WPL HOLDINGS INC
S-4/A, 1996-08-22
ELECTRIC & OTHER SERVICES COMBINED
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<PAGE>
   
                                                      Registration No. 333-10401
    
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                           --------------------------
 
   
                                   AMENDMENT
                                    NO. 1 TO
    
                                    FORM S-4
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
 
                               WPL HOLDINGS, INC.
             (Exact name of registrant as specified in its charter)
                 [TO BE RENAMED INTERSTATE ENERGY CORPORATION]
 
<TABLE>
<S>                                 <C>                                 <C>
            WISCONSIN                              6719                             39-1380265
 (State or other jurisdiction of       (Primary Standard Industrial              (I.R.S. Employer
  incorporation or organization)       Classification Code Number)             Identification No.)
</TABLE>
 
                           222 WEST WASHINGTON AVENUE
                            MADISON, WISCONSIN 53703
                                 (608) 252-3311
         (Address, including zip code, and telephone number, including
            area code, of registrant's principal executive offices)
 
                              ERROLL B. DAVIS, JR.
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                               WPL HOLDINGS, INC.
                           222 WEST WASHINGTON AVENUE
                            MADISON, WISCONSIN 53703
                                 (608) 252-3311
      (Name, address, including zip code, and telephone number, including
                        area code, of agent for service)
                           --------------------------
 
                            INTERSTATE POWER COMPANY
             (Exact name of registrant as specified in its charter)
 
<TABLE>
<S>                                 <C>                                 <C>
            WISCONSIN                              4939                             42-1457523
 (State or other jurisdiction of       (Primary Standard Industrial              (I.R.S. Employer
  incorporation or organization)       Classification Code Number)             Identification No.)
</TABLE>
 
                                1000 MAIN STREET
                              DUBUQUE, IOWA 52001
                                 (319) 582-5421
         (Address, including zip code, and telephone number, including
            area code, of registrant's principal executive offices)
 
                                MICHAEL R. CHASE
                                   PRESIDENT
                            INTERSTATE POWER COMPANY
                                1000 MAIN STREET
                              DUBUQUE, IOWA 52001
                                 (319) 582-5421
      (Name, address, including zip code, and telephone number, including
                        area code, of agent for service)
                           --------------------------
 
                        COPIES OF ALL CORRESPONDENCE TO:
 
<TABLE>
<S>                                 <C>                                 <C>
  Benjamin F. Garmer, III, Esq.         Stephen W. Southwick, Esq.            M. Douglas Dunn, Esq.
         Foley & Lardner            Vice President, General Counsel &    Milbank, Tweed, Hadley & McCloy
    777 East Wisconsin Avenue                   Secretary                    1 Chase Manhattan Plaza
     Milwaukee, WI 53202-5367              IES Industries Inc.                  New York, NY 10005
                                                IES Tower
                                          200 First Street S.E.
                                          Cedar Rapids, IA 52401
</TABLE>
 
    APPROXIMATE  DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after this  Registration Statement becomes  effective and all  other
conditions to the Mergers as defined herein have been satisfied or waived.
 
    If  the  securities  being registered  on  this  Form are  being  offered in
connection with the formation of a holding company and there is compliance  with
General Instruction G, check the following box. / /
                           --------------------------
 
   
    Pursuant  to Rule  429 under  the Securities  Act of  1933, the  Joint Proxy
Statement/Prospectus and  the  Supplement  thereto contained  as  part  of  this
Registration  Statement on Form S-4 also relate to the Registration Statement on
Form S-4 (Registration No. 333-07931).
    
                           --------------------------
 
    THE REGISTRANTS HEREBY  AMEND THIS  REGISTRATION STATEMENT ON  SUCH DATE  OR
DATES  AS MAY  BE NECESSARY  TO DELAY ITS  EFFECTIVE DATE  UNTIL THE REGISTRANTS
SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS  REGISTRATION
STATEMENT  SHALL THEREAFTER BECOME EFFECTIVE IN  ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT  OF 1933 OR  UNTIL THIS REGISTRATION  STATEMENT SHALL  BECOME
EFFECTIVE  ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
                               WPL HOLDINGS, INC.
                 [TO BE RENAMED INTERSTATE ENERGY CORPORATION]
                            INTERSTATE POWER COMPANY
 
               CROSS REFERENCE SHEET SHOWING THE LOCATION IN THE
 JOINT PROXY STATEMENT/PROSPECTUS AND THE SUPPLEMENT THERETO OF THE INFORMATION
              REQUIRED BY ITEMS 1 THROUGH 19, PART I, OF FORM S-4
 
<TABLE>
<CAPTION>
ITEM NUMBER AND CAPTION OF FORM S-4                                                            LOCATION
- ------------------------------------------------------------------------  --------------------------------------------------
<C>        <C>        <S>                                                 <C>
       A.  Information About the Transaction
                  1.  Forepart of Registration Statement and Outside
                       Front Cover Page of Prospectus...................  Facing Page of Registration Statement; Cross
                                                                           Reference Sheet; Cover Page of Prospectus
                  2.  Inside Front and Outside Back Cover Pages of
                       Prospectus.......................................  Available Information; Incorporation of Documents
                                                                           by Reference (in the Joint Proxy
                                                                           Statement/Prospectus and the Supplement thereto);
                                                                           Table of Contents
                  3.  Risk Factors, Ratio of Earnings to Fixed Charges
                       and Other Information............................  Summary; Selected Historical and Pro Forma
                                                                           Financial Data; Recent Developments
                  4.  Terms of Transaction..............................  Summary; The Mergers; The Merger Agreement; The
                                                                           Stock Option Agreements; Description of
                                                                           Interstate Energy Capital Stock; Amendments to
                                                                           WPLH Restated Articles of Incorporation;
                                                                           Comparison of Shareowner Rights; Interstate
                                                                           Energy Following the Mergers; Recent Developments
                  5.  Pro Forma Financial Information...................  Unaudited Pro Forma Combined Financial Information
                                                                           (in the Joint Proxy Statement/Prospectus and the
                                                                           Supplement thereto)
                  6.  Material Contacts with the Company Being
                       Acquired.........................................  Summary; The Mergers; The Merger Agreement; The
                                                                           Stock Option Agreements; Selected Information
                                                                           Concerning WPLH, IES and IPC; Recent Developments
                  7.  Additional Information Required for Reoffering by
                       Person and Parties Deemed to be Underwriters.....  Not Applicable
                  8.  Interests of Named Experts and Counsel............  Legal Matters
                  9.  Disclosure of Commission Position on
                       Indemnification for Securities Act Liabilities...  Not Applicable
       B.  Information About the Registrant
                 10.  Information With Respect to S-3 Registrants.......  Incorporation of Documents by Reference (in the
                                                                           Joint Proxy Statement/Prospectus and the
                                                                           Supplement thereto)
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
ITEM NUMBER AND CAPTION OF FORM S-4                                                            LOCATION
- ------------------------------------------------------------------------  --------------------------------------------------
<C>        <C>        <S>                                                 <C>
                 11.  Incorporation of Certain Information by
                       Reference........................................  Incorporation of Documents by Reference (in the
                                                                           Joint Proxy Statement/Prospectus and the
                                                                           Supplement thereto)
                 12.  Information With Respect to S-2 or S-3
                       Registrants......................................  Not Applicable
                 13.  Incorporation of Certain Information by
                       Reference........................................  Not Applicable
                 14.  Information With Respect to Registrants Other Than
                       S-3 or S-2 Registrants...........................  Summary; The Mergers; Selected Historical and Pro
                                                                           Forma Data; Selected Information Concerning WPLH,
                                                                           IES and IPC; Annex S
       C.  Information About the Company Being Acquired
                 15.  Information With Respect to S-3 Companies.........  Incorporation of Documents by Reference
                 16.  Information With Respect to S-2 or S-3
                       Companies........................................  Not Applicable
                 17.  Information With Respect to Companies Other Than
                       S-3 or S-2 Companies.............................  Not Applicable
       D.  Voting and Management Information
                 18.  Information if Proxies, Consents or Authorizations
                       are to be Solicited..............................  Incorporation of Documents by Reference; Summary;
                                                                           Meetings, Voting and Proxies; The Mergers;
                                                                           Selected Information Concerning WPLH, IES and
                                                                           IPC; For WPLH -- Election of WPLH Directors,
                                                                           Meetings and Committees of WPLH Board, Ownership
                                                                           of Voting Securities, Compensation of Executive
                                                                           Officers*, Comparison of Five-Year Cumulative
                                                                           Total Return*; For IES -- Election of IES
                                                                           Directors, Security Ownership of Beneficial
                                                                           Owners, Security Ownership of Management, Other
                                                                           Transactions, Functioning of the IES Board and
                                                                           Committees, Compensation of Directors, Report of
                                                                           the Compensation Committee on Executive
                                                                           Compensation*, Performance Graph*, IES Plans,
                                                                           Iowa Southern Utilities Plans, Employment
                                                                           Agreement; For IPC -- Election of IPC Directors,
                                                                           Principal Holders of Voting Securities,
                                                                           Compensation of Directors and Executive Officers*
                 19.  Information if Proxies, Consents or Authorizations
                       are not to be Solicited or in an Exchange
                       Offer............................................  Not Applicable
</TABLE>
 
- ------------------------
* In  accordance  with  Item 402(a)(8)  and  (9)  of Regulation  S-K,  the board
  compensation committee report  on executive compensation  and the  performance
  graph  information under these captions is provided for the purpose of WPLH's,
  IES's or IPC's Proxy Statement  only and is not intended  to be a part of  the
  Joint  Registration  Statement,  the  Prospectus  or  the  Supplement  to  the
  Prospectus.
<PAGE>
                        [WPL HOLDINGS, INC. LETTERHEAD]
                                                            ERROLL B. DAVIS, JR.
                                                             PRESIDENT AND CHIEF
                                                               EXECUTIVE OFFICER
 
   
August 21, 1996
    
 
Dear WPL Holdings, Inc. Shareowner:
 
    On August 15, 1996, your Board of Directors approved an amendment to the
Agreement and Plan of Merger (the "Merger Agreement") for the strategic
three-way business combination of WPL Holdings, Inc. ("WPLH"), Cedar Rapids,
Iowa-based IES Industries Inc. ("IES") and Dubuque, Iowa-based Interstate Power
Company ("IPC").
 
    Under the terms of the revised Merger Agreement, which was also approved by
the Boards of Directors of IES and IPC, each share of IES common stock will be
converted into 1.14 shares of Interstate Energy Corporation common stock at the
time of the consummation of the merger transaction. Under the prior arrangement,
each share of IES common stock was to be converted into 1.01 shares of
Interstate Energy Corporation common stock. The IES exchange ratio was adjusted
in conjunction with the rejection by the IES Board of an unsolicited proposal
made for IES by Des Moines, Iowa-based MidAmerican Energy Company.
 
    Only the IES exchange ratio has been adjusted under the revised Merger
Agreement. As under the prior arrangement, each share of IPC common stock will
be converted into 1.11 shares of Interstate Energy Corporation common stock and
each share of WPLH common stock will represent one share of Interstate Energy
Corporation common stock following consummation of the merger transaction.
 
   
    Your Board of Directors continues to believe that the proposed transaction
between WPLH, IES and IPC will result in a combined entity that will be
well-positioned to compete in an increasingly competitive utility industry
environment. The Board further believes that the increased IES exchange ratio is
justified by the strategic value of the three-way combination. The Board has
received a written opinion from its financial advisor, Merrill Lynch, Pierce,
Fenner & Smith Incorporated, dated August 21, 1996, to the effect that, as of
such date, and based upon the assumptions made, matters considered and limits of
review set forth in such opinion, the revised IES exchange ratio and the IPC
exchange ratio, taken together, are fair, from a financial point of view, to
WPLH.
    
 
    The 1996 WPLH Annual Meeting remains scheduled for Thursday, September 5,
1996, at the Exhibition Hall at the Dane County Expo Center, 1881 Expo Mall,
Madison, Wisconsin. The WPLH Annual Meeting will be held immediately following
the Annual Meeting of Shareowners of Wisconsin Power and Light Company, which
meeting will start at 10:00 a.m. (Central Time).
 
    Your Board of Directors believes that each of the proposals to be voted on
at the WPLH Annual Meeting (including the proposal to approve the revised Merger
Agreement and the transactions contemplated thereby) is in the best interests of
WPLH and its shareowners, and unanimously recommends that shareowners vote "FOR"
each of the proposals.
 
    We have enclosed an additional proxy card for the WPLH Annual Meeting for
your use. IF YOU HAVE ALREADY MAILED A PROXY FOR THE WPLH ANNUAL MEETING, YOU
NEED NOT RETURN THE ENCLOSED CARD UNLESS YOU WISH TO CHANGE YOUR VOTE, WHICH YOU
MAY DO BY COMPLETING, SIGNING, DATING AND RETURNING THE ENCLOSED PROXY. SUCH NEW
PROXY WHEN RECEIVED WILL SUPERSEDE YOUR EARLIER PROXY. IF YOU HAVE NOT ALREADY
RETURNED A PROXY, YOU ARE URGED TO RETURN THE ENCLOSED PROXY AS SOON AS
POSSIBLE.
 
    The accompanying Supplement to the Joint Proxy Statement/Prospectus provides
shareowners with further details regarding the revised Merger Agreement and
other recent developments. If you have any questions about these specific
matters or about the WPLH Annual Meeting in general, please call Shareowner
Services at 608-252-3110 (local) or 1-800-356-5343 (toll-free).
 
                                          Sincerely,
 
                                            [/S/ ERROLL B. DAVIS, JR.]
 
                                          Erroll B. Davis, Jr.
                                          PRESIDENT AND CHIEF EXECUTIVE OFFICER
<PAGE>
                        [IES Industries Inc. Letterhead]
 
Dear IES Industries Inc. Shareholder:
 
    Enclosed is a copy of the Supplement to Joint Proxy Statement/Prospectus
relating to the matters to be voted on at the annual meeting of shareholders on
Thursday, September 5, 1996. IES Industries seeks your approval of a revised
agreement for a strategic three-way business combination among IES, WPL
Holdings, Inc. ("WPLH") and Interstate Power Company ("IPC"), to create a new
regional energy powerhouse, Interstate Energy Corporation.
 
    Your Board of Directors believes the combination of IES, WPLH and IPC will
result in a strong business organization able to take advantage of attractive
regional opportunities in both its core utility and its diversified businesses.
 
   
    Under the terms of the revised agreement for the proposed transaction, which
was also approved by the Boards of WPLH and IPC, each share of IES common stock
will be converted into 1.14 shares of Interstate Energy common stock (the "IES
Ratio"). Under the new terms, it is anticipated that the value to IES
shareholders of Interstate Energy's initial annual cash dividend will be $2.25
per share of IES common stock. As under the prior agreement, each share of IPC
common stock will be converted into 1.11 shares of Interstate Energy common
stock (the "IPC Ratio").
    
 
   
    Under the former agreement, each IES common share was to be converted into
1.01 shares of Interstate Energy common stock. Under the revised agreement, the
Interstate Energy transaction provides enhanced value to IES shareholders,
giving them an even bigger stake in a regional utility with excellent growth
potential. In addition, the Board received a written opinion dated the date
hereof from its financial advisor, Morgan Stanley & Co. Incorporated, to the
effect that, as of such date, and based upon the procedures and subject to the
assumptions described therein, the revised IES Ratio, taking into account the
IPC Ratio, is fair from a financial point of view to the holders of IES common
stock.
    
 
    THE IES BOARD OF DIRECTORS HAS CAREFULLY REVIEWED AND CONSIDERED THE TERMS
AND CONDITIONS OF THE MERGER TO BE VOTED UPON AT THE IES ANNUAL MEETING AND
BELIEVES IT IS IN THE BEST INTERESTS OF IES AND ITS SHAREHOLDERS AND RECOMMENDS
THAT SHAREHOLDERS VOTE "FOR" THE PROPOSALS DESCRIBED IN THE ATTACHED SUPPLEMENT
TO JOINT PROXY STATEMENT/PROSPECTUS.
 
    In addition, IES shareholders will be asked to elect nine directors to serve
until the next annual meeting of IES shareholders or until their successors are
elected and qualified.
 
   
    The IES Board also unanimously (with one abstention by a director who was
not eligible to vote on the matter) rejected the hostile takeover proposal from
MidAmerican Energy of Des Moines, Iowa, concluding that it is inferior to the
terms of the revised Interstate Energy merger agreement and is not in the best
interests of IES shareholders. The Board also viewed with concern the impact of
the proposed MidAmerican transaction on customers, employees and the communities
IES has served for more than 100 years.
    
 
   
    Despite your Board's rejection of MidAmerican's hostile offer, MidAmerican
has sent you materials asking you to vote against our merger with WPLH and IPC,
and to support their takeover. Your Board strongly urges that you do NOT return
any solicitation materials received from MidAmerican.
    
 
    WE HAVE ENCLOSED AN ADDITIONAL PROXY/DIRECTION CARD FOR THE ANNUAL MEETING
FOR YOUR USE. IES STRONGLY URGES YOU TO VOTE FOR THE REVISED INTERSTATE ENERGY
MERGER (PROPOSAL 2) ON THE ENCLOSED WHITE PROXY/ DIRECTION CARD. TIME IS SHORT,
SO PLEASE SIGN, DATE AND RETURN THE ENCLOSED WHITE PROXY/DIRECTION CARD IN THE
POSTAGE PAID ENVELOPE TODAY. EVEN IF YOU HAVE PREVIOUSLY VOTED AGAINST THE
MERGER, ON EITHER IES'S PROXY/ DIRECTION CARD OR MIDAMERICAN'S PROXY/DIRECTION
CARD, THERE IS STILL TIME TO CHANGE YOUR MIND BY SIGNING, DATING AND RETURNING
THE ENCLOSED WHITE PROXY/DIRECTION CARD FOR A VOTE FOR PROPOSAL 2. REMEMBER,
ONLY YOUR LATEST DATED, VALIDLY EXECUTED PROXY/DIRECTION CARD COUNTS, SO PLEASE
ACT TODAY. AS A SHAREHOLDER, IT IS IN YOUR BEST INTEREST, AS WELL AS HELPFUL TO
YOUR BOARD OF DIRECTORS, THAT YOU PARTICIPATE IN THE AFFAIRS OF IES, WHETHER YOU
OWN A FEW SHARES OR MANY SHARES.
<PAGE>
    Let me express my appreciation for your past cooperation. I look forward to
your continued interest in IES.
 
   
    Whether or not you plan to attend the Annual Meeting, please promptly
complete, sign, date and return the enclosed proxy/direction card in the
enclosed postage prepaid envelope. You may, of course, attend the Annual Meeting
and vote in person, even if you have previously returned your proxy card. The
Annual Meeting will be held at the Collins Plaza Hotel, 1200 Collins Road N.E.,
Cedar Rapids, Iowa, on September 5, 1996 at 10:00 a.m. (Central Time). If you
have any questions about the IES Annual Meeting, please call Georgeson & Co.,
IES's proxy solicitor, at (800) 223-2064.
    
 
    On behalf of your Board of Directors, thank you for your continued support.
 
                                          Sincerely,
 
                                                      [/S/ LEE LIU]
                                          Lee Liu
                                          Chairman of the Board,
                                          President & Chief
                                          Executive Officer
   
August 21, 1996
    
<PAGE>
                     [INTERSTATE POWER COMPANY LETTERHEAD]
 
                                                            WAYNE H. STOPPELMOOR
                                                          CHAIRMAN OF THE BOARD,
                                                             PRESIDENT AND CHIEF
                                                               EXECUTIVE OFFICER
   
                                August 21, 1996
    
 
Dear Interstate Power Company Stockholder:
 
    On August 15, 1996, your Board of Directors approved an amendment to the
Agreement and Plan of Merger (the "Merger Agreement") for the strategic
three-way business combination of Interstate Power Company ("IPC"), Madison,
Wisconsin-based WPL Holdings, Inc. ("WPLH") and Cedar Rapids, Iowa-based IES
Industries Inc. ("IES").
 
    Under the terms of the revised Merger Agreement, which was also approved by
the Boards of Directors of WPLH and IES, each share of IES common stock will be
converted into 1.14 shares of Interstate Energy Corporation common stock at the
time of the consummation of the merger transaction. Under the prior arrangement,
each share of IES common stock was to be converted into 1.01 shares of
Interstate Energy Corporation common stock. The IES exchange ratio was adjusted
in conjunction with the rejection by the IES Board of an unsolicited takeover
proposal made for IES by Des Moines, Iowa-based MidAmerican Energy Company.
 
    Only the IES exchange ratio has been adjusted under the revised Merger
Agreement. As under the prior arrangement, each share of IPC common stock will
be converted into 1.11 shares of Interstate Energy Corporation common stock and
each share of WPLH common stock will represent one share of Interstate Energy
Corporation common stock following consummation of the merger transaction.
 
   
    Your Board of Directors continues to believe that the proposed transaction
between IPC, WPLH and IES will result in a combined entity that will be
well-positioned to compete in an increasingly competitive utility industry
environment. The Board further believes that the increased IES exchange ratio is
justified by the strategic value of the three-way combination. The Board has
received a written opinion from its financial advisor, Salomon Brothers Inc,
dated August 21, 1996, to the effect that, as of such date, and based upon the
assumptions made, matters considered and limits of review set forth in such
opinion, the IPC exchange ratio is fair to the holders of IPC common stock from
a financial point of view.
    
 
    The 1996 IPC Annual Meeting remains scheduled for Thursday, September 5,
1996, at the Holiday Inn Dubuque Five Flags, 450 Main Street, Dubuque, Iowa at
10:00 a.m. (Central Time).
 
   
    Your Board of Directors believes that each of the proposals to be voted on
at the IPC Annual Meeting (including the proposal to approve the revised Merger
Agreement and the transactions contemplated thereby) is in the best interests of
IPC and its stockholders, and unanimously recommends that stockholders vote
"FOR" each of the proposals.
    
 
    We have enclosed an additional proxy card for the IPC Annual Meeting for
your use. IF YOU HAVE ALREADY MAILED A PROXY FOR THE IPC ANNUAL MEETING, YOU
NEED NOT RETURN THE ENCLOSED CARD. If you wish to change your vote, you may do
so by completing, signing, dating and returning the enclosed proxy which when
received, will supersede your earlier proxy. If you have not already returned a
proxy, I urge you to return the enclosed proxy as soon as possible.
<PAGE>
    The accompanying Supplement to the Joint Proxy Statement/Prospectus provides
stockholders with further details regarding the revised Merger Agreement and
other recent developments. If you have any questions about these specific
matters or about the IPC Annual Meeting in general, please call IPC Stockholder
Services at 319-582-5421, ext. 465.
 
                                          Sincerely,
 
                                           [/S/ WAYNE H. STOPPELMOOR]
 
                                          Wayne H. Stoppelmoor
                                          CHAIRMAN OF THE BOARD,
                                          PRESIDENT AND CHIEF
                                          EXECUTIVE OFFICER
<PAGE>
                                 SUPPLEMENT TO
                             JOINT PROXY STATEMENT
                                       OF
                              WPL HOLDINGS, INC.,
                              IES INDUSTRIES INC.
                                      AND
                            INTERSTATE POWER COMPANY
                            (A DELAWARE CORPORATION)
                            ------------------------
 
                                   PROSPECTUS
                                   SUPPLEMENT
                                       OF
 
<TABLE>
<S>                                         <C>        <C>
            WPL HOLDINGS, INC.
              TO BE RENAMED
      INTERSTATE ENERGY CORPORATION                             INTERSTATE POWER COMPANY
        (A WISCONSIN CORPORATION)              AND             (A WISCONSIN CORPORATION)
    relating to shares of common stock                   relating to shares of preferred stock
      (and accompanying common stock
             purchase rights)
</TABLE>
 
                            ------------------------
 
    This Supplement to Joint Proxy Statement/Prospectus relates to the proposed
combination of WPL Holdings, Inc. ("WPLH"), IES Industries Inc. ("IES") and
Interstate Power Company ("IPC") into a single entity to be known after the
combination as Interstate Energy Corporation ("Interstate Energy"). This
Supplement supplements, and should be read in conjunction with, the Joint Proxy
Statement/Prospectus dated July 11, 1996 (the "Original Joint Proxy
Statement/Prospectus"). The Original Joint Proxy Statement/Prospectus is
modified as set forth herein. Capitalized terms used herein and not otherwise
defined have the meanings ascribed to such terms in the Original Joint Proxy
Statement/Prospectus.
 
    The purpose of this Supplement is to inform the shareowners of WPLH, IES and
IPC that the Merger Agreement has been amended to increase the IES Ratio from
1.01 to 1.14 (which represents a value per share of IES Common Stock of $36.20,
based upon the closing price per share of WPLH Common Stock of $31 3/4 on August
15, 1996), and to seek approval from such shareowners for the Merger Agreement,
as so amended, at the annual meetings of WPLH, IES and IPC scheduled to be held
on Thursday, September 5, 1996. See "Recent Developments."
                            ------------------------
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
 EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
   COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY
     OR ADEQUACY OF THE ORIGINAL JOINT PROXY STATEMENT/ PROSPECTUS AS
      SUPPLEMENTED BY THIS SUPPLEMENT. ANY     REPRESENTATION TO THE
                        CONTRARY IS A CRIMINAL OFFENSE.
                            ------------------------
 
   
    This Supplement to Joint Proxy Statement/Prospectus and accompanying forms
of proxy are first being mailed to shareowners of WPLH, IES and IPC on or about
August 23, 1996.
    
 
   
 THE DATE OF THIS SUPPLEMENT TO JOINT PROXY STATEMENT/PROSPECTUS IS AUGUST 21,
                                     1996.
    
<PAGE>
                              RECENT DEVELOPMENTS
 
BACKGROUND OF THE MERGERS
 
    On November 10, 1995, WPLH, IES and IPC entered into the Merger Agreement,
which was subsequently amended by Amendment No. 1 thereto, dated May 22, 1996.
Each of the parties to the Merger Agreement has scheduled an annual meeting for
September 5, 1996 at which the respective shareowners of WPLH, IES and IPC are
to vote to approve, among other things, the Merger Agreement and the
transactions contemplated thereby. On August 4, 1996, MidAmerican Energy Company
("MEC") made an unsolicited takeover proposal for IES.
 
    A predecessor of MEC had previously entered into a Confidentiality and
Standstill Agreement with IES dated August 16, 1993 (the "Standstill
Agreement"), which provided, among other things, that until August 1, 1996,
neither party would,
 
    without the prior written consent of the Board of Directors of the other
    party (i) in any manner acquire, agree to acquire or make any proposal to
    acquire, directly or indirectly, any securities of the other party or any of
    its subsidiaries, (ii) in any manner acquire, agree to acquire or make any
    proposal to acquire, directly or indirectly, any property of the other party
    or any of its subsidiaries, except in the ordinary course of business, (iii)
    make, or in any way participate, directly or indirectly, in any
    "solicitation" of "proxies" (as such terms are used in the proxy rules of
    the Securities and Exchange Commission) to vote, or seek to advise or
    influence any person with respect to the voting of, any voting securities of
    the other party or any of its subsidiaries, (iv) form, join or in any way
    participate in a "group" (within the meaning of Section 13(d)(3) of the
    Securities Exchange Act of 1934, as amended) with respect to any voting
    securities of the other party or any of its subsidiaries, (v) otherwise act,
    alone or in concert with others, to seek to control or influence the
    management, Board of Directors or policies of the other party, (vi) disclose
    any intention, plan or arrangement inconsistent with the foregoing, or (vii)
    advise, assist or encourage any other persons in connection with the
    foregoing.
 
Each party also agreed, until August 1, 1996,
 
    not to (i) request the other party or its Representatives, directly or
    indirectly, to amend or waive any provision of this paragraph (including
    this sentence) or (ii) take any action which might require the other party
    to make a public announcement regarding the possibility of a business
    combination or merger.
 
    Notwithstanding the restrictions contained in the Standstill Agreement, in
August 1995 executives of MEC approached Lee Liu, Chairman of the Board,
President & Chief Executive Officer of IES, to discuss a potential business
combination between MEC and IES. MEC did not propose any terms for such a
combination and IES indicated that it was not interested in discussing such a
combination at that time. MEC then sent letters to IES dated October 3 and
October 10, 1995, requesting discussions with IES concerning a possible
combination. Neither of these letters contained any proposed terms for such a
combination and IES again declined to enter into discussions with MEC. IES
responded to MEC's first letter on October 6, 1995, writing that members of the
IES Board had discussed MEC's letter, and that at that time, IES was "not
interested in entering into discussion with [MEC] relative to a possible
business combination."
 
    Also notwithstanding the restrictions contained in the Standstill Agreement,
on October 23, 1995 MEC formally requested that the IES Board grant it
permission to make a formal business combination proposal. In the letter, MEC
indicated that such a formal proposal would contain, among other things, the
following terms: (i) a "merger of equals" between MEC and IES after receipt of
all appropriate approvals; (ii) an exchange ratio of common stock to provide a
premium to IES shareholders of 15% over its $26.875 market value at closing on
October 20, 1995 (premised and conditioned on 29,290,660 outstanding shares of
IES Common Stock); (iii) the combined company would continue to maintain a
"significant and appropriate" presence in Cedar Rapids; and (iv) IES
shareholders would have "appropriate" representation on the combined company's
Board of Directors.
 
                                       2
<PAGE>
    On October 26, 1995, IES informed MEC that it would consider its request at
the next regular IES Board meeting in November.
 
    On November 10, 1995, the IES Board held a meeting at which it discussed,
among other things, the proposed terms of MEC's combination proposal. After
discussion and consultation with its legal and financial advisors and a review
of its previous strategic option evaluations as discussed in the Original Joint
Proxy Statement/Prospectus under the caption "The Mergers -- Background of the
Mergers," the IES Board determined not to pursue the MEC proposal and approved
the Merger Agreement. Later that day, IES entered into the Merger Agreement with
WPLH and IPC.
 
    On Thursday, August 1, 1996, the Standstill Agreement terminated and
thereafter, on Sunday, August 4, MEC delivered a letter to IES with a formal
takeover proposal (the "MEC Takeover Proposal"). Mr. Liu subsequently informed
Erroll B. Davis, Jr., President and Chief Executive Officer of WPLH, and Wayne
H. Stoppelmoor, Chairman of the Board, President and Chief Executive Officer of
IPC, of the MEC Takeover Proposal. MEC also delivered to IES a demand, from
Regina Rae Huggins, a holder of four shares of IES Common Stock, for a list of
the IES shareholders.
 
    The MEC Takeover Proposal was premised upon the withdrawal by IES from its
proposed transaction with WPLH and IPC. MEC stated that the MEC Takeover
Proposal had been approved and authorized by MEC's Board of Directors. The MEC
Takeover Proposal contained, among other things, the following terms: (i) IES
would merge with and into MEC or with a subsidiary of MEC; (ii) the aggregate
consideration would be 40% cash (or less if shareholders so elected) and the
remainder in MEC common stock, to be allocated in accordance with customary
election and allocation procedures to be set forth in a new merger agreement;
(iii) IES common shareholders electing to receive cash would receive $39 for
each share of IES Common Stock; (iv) IES common shareholders electing to receive
stock would receive 2.346 shares of MEC common stock for each share of IES
Common Stock (which has a value of $37.24 per share of IES Common Stock, based
upon the closing price of MEC common stock of $15 7/8 per share on August 15,
1996); (v) a new merger agreement would include "the same representations and
warranties and substantially the same applicable terms, conditions and
covenants" as the Merger Agreement; (vi) the headquarters of the combined
company would be in Des Moines, Iowa; (vii) the combined company would continue
to maintain a "significant" presence in Cedar Rapids; (viii) the proposed
transaction would be accounted for as a purchase rather than a pooling of
interests; and (ix) the Board of the combined company would include an
unspecified number of directors from IES.
 
    On Monday, August 5, the IES Board, together with its counsel, Winthrop,
Stimson, Putnam & Roberts, and its financial advisor, Morgan Stanley & Co.
Incorporated ("Morgan Stanley"), held a telephonic meeting at which the
participants discussed the status of the Standstill Agreement, the MEC Takeover
Proposal and the options available to the IES Board. The IES Board scheduled a
meeting for August 14 for further discussion of the MEC Takeover Proposal with
its legal and financial advisors. Thereafter, IES issued a press release
indicating that it had received the MEC Takeover Proposal and that it would be
considered and evaluated by the IES Board. In the press release, IES also
requested that its shareholders take no action until the IES Board had fully
evaluated the MEC Takeover Proposal.
 
    In the eight days following the August 5, 1996 announcement of the MEC
Takeover Proposal, and prior to the August 14, 1996 IES Board meeting, IES's
directors and officers continued to examine the MEC Takeover Proposal and to
consult with IES's legal and financial advisors concerning their options and
obligations. On August 7, 1996, Mr. Liu and Larry Root, a former executive
officer of and now a consultant to IES, held a conference call with counsel to
IES and with Morgan Stanley. IES retained Georgeson & Co. ("Georgeson") to act
as its individual proxy solicitor and Kekst & Co. ("Kekst") to assist with
public relations. For its services, Georgeson will be paid a fee not to exceed
$500,000 on the following basis: $200,000 payable upon execution of an
arrangement with IES, $200,000 payable September 8, 1996, and if Georgeson's
services are required after December 7, 1996, an additional $100,000 payable
December 8, 1996. IES will also pay Georgeson an additional $6.00 per
 
                                       3
<PAGE>
phone call to individual shareholders and non-objecting beneficial owners and
for incoming calls from such owners, which fees shall include all telephone
charges. In addition, the respective counsel and financial advisors of WPLH, IES
and IPC held several informal, nonsubstantive discussions during this period
regarding the status of the MEC Takeover Proposal and the Merger Agreement.
 
    On Friday, August 9, 1996, IES issued a press release, together with letters
to its shareholders and employees, informing them that the IES Board would be
meeting to evaluate the MEC Takeover Proposal. IES urged its shareholders not to
act until the IES Board had made its recommendation. IES also made available its
shareholder list to Ms. Huggins on August 9, 1996.
 
   
    Also on August 9, 1996, Stanley J. Bright, President and Chief Executive
Officer of MEC, called Mr. Stoppelmoor. Mr. Bright informed Mr. Stoppelmoor of
the MEC Takeover Proposal and indicated that the purpose of the call was merely
a courtesy to Mr. Stoppelmoor. Messrs. Bright and Stoppelmoor did not engage in
any substantive discussion of the MEC Takeover Proposal or any other matter.
    
 
    On Sunday, August 11, 1996, Messrs. Liu and Root and Stephen Southwick, Vice
President, General Counsel & Secretary of IES, held a conference call with
counsel to IES and with Morgan Stanley, during which the participants discussed
the MEC Takeover Proposal. Mr. Liu authorized Morgan Stanley to contact Merrill
Lynch, Pierce, Fenner & Smith Incorporated ("Merrill Lynch"), WPLH's financial
advisor, and Salomon Brothers Inc ("Salomon Brothers"), IPC's financial advisor,
to discuss IES's interest in increasing the IES Ratio in light of the MEC
Takeover Proposal.
 
    During this period, senior management of WPLH held several discussions with
Merrill Lynch and with Foley & Lardner, WPLH's legal counsel, and Mr.
Stoppelmoor held several discussions with Salomon Brothers and Milbank, Tweed,
Hadley & McCloy, IPC's financial and legal advisors, to discuss the
ramifications of the MEC Takeover Proposal on the transactions contemplated by
the Merger Agreement. On August 13, 1996, representatives of WPLH and IPC, along
with their respective legal and financial advisors, held several conference
calls regarding increasing the IES Ratio in light of the MEC Takeover Proposal
and in response to discussions such financial advisors had with Morgan Stanley.
 
    On August 14, 1996, Mr. Stoppelmoor called Mr. Liu to inform him that WPLH
and IPC managements, after consulting with members of their respective Boards of
Directors and financial and legal advisors, would be prepared to recommend to
their Boards of Directors that the IES Ratio be increased from 1.01 to 1.11.
 
   
    Also on August 14, 1996, the IES Board met in Chicago. All directors were
present for the meeting. Representatives of Arthur Andersen Economic Consulting,
Morgan Stanley, Winthrop, Stimson, Putnam & Roberts, Georgeson and Kekst were
also present at the request of the IES Board. At such meeting, Arthur Andersen
Economic Consulting reviewed certain publicly available information with respect
to the MEC Takeover Proposal and the Mergers, as well as its analysis presented
at the October 5, 1995 IES Board meeting, which had not been updated. Its
representative discussed the following factors: (i) WPLH's price to earnings
ratio at the time of Arthur Andersen Economic Consulting's 1995 study, based on
1994 earnings, was approximately 16, compared with MEC's pro forma price to
earnings ratio, based on the individual MEC constituent corporations' price to
earnings ratios of approximately 12; (ii) the total return to shareholders of
WPLH during the period 1990-1994 was $1.55 for every dollar invested at the
beginning of the period, while returns to shareholders of the constituent
corporations that formed MEC during the same period was $1.08 and $1.26 for
every dollar invested at the beginning of the period, assuming in each case that
dividends were reinvested; (iii) WPLH's bond rating is higher than that of MEC,
WPLH's long-term debt is approximately 36% of capitalization compared to 51% for
MEC, and MEC has stated publicly that its debt ratio may increase beyond the
range of its present debt rating due to the additional indebtedness it intends
to incur to acquire IES; (iv) MEC's potential stranded costs (defined as
expenditures made for prior utility investments in generation or other plant
and/or property that may not be recoverable through rates in the new competitive
environment), estimated in 1995 by Moody's Investor Service, are approximately
$172 million, while Moody's estimated no stranded costs for WPLH; (v) MEC's
average cost per
    
 
                                       4
<PAGE>
   
kilowatt-hour for 1994 was 5.5 CENTS, while WPLH's average cost per
kilowatt-hour was 4.9 CENTS and IES's average cost per kilowatt-hour was
5.2 CENTS; (vi) under the MEC Takeover Proposal, IES shareholders would receive
29% of the combined company (assuming that 40% of the consideration is cash)
compared to 34% in MEC's October 1995 proposal and 42% in the Mergers under the
Merger Agreement as it existed on August 14, 1996; (vii) the MEC Takeover
Proposal would concentrate regulatory matters primarily before a single state
commission, while a combination involving WPLH would subject the combined entity
to less concentrated regulation at the state level; (viii) MEC's then-current
estimate of synergies from the MEC Takeover Proposal of more than $500 million
over ten years (which MEC has since increased to an amount in excess of $650
million), based exclusively on publicly available information relating to IES,
contrasts with IES's estimated synergies resulting from the Mergers of $677
million over the same period, based exclusively on publicly available
information so that, based upon these estimates, at the relevant percentages of
ownership and assuming that 40% of the consideration in the MEC Takeover
Proposal is cash, IES would receive an estimated average benefit of $15 million
per year before taxes from the MEC transaction, compared to an estimated average
benefit of $28 million per year it would receive from the Mergers; and (ix)
Arthur Andersen Economic Consulting's view that MEC's methodology in estimating
labor synergies yields higher estimates than does IES's methodology, such that
if IES's estimate of labor savings were applied to the MEC Takeover Proposal the
combined company would be expected to achieve less than $400 million in
synergies over ten years, while if MEC's estimate of labor savings were applied
to the Mergers, Interstate Energy would be expected to achieve synergies of more
than $800 million over the same period. Arthur Andersen Economic Consulting also
informed the IES Board that the MEC Takeover Proposal stated that it would
result in approximately 450 lost jobs while its September 1995 analysis of a
hypothetical IES/MEC merger, based solely on publicly available data, estimated
less than 110 jobs would be lost. Finally, Arthur Andersen Economic Consulting
observed that the impact of the sale of underperforming and non-strategic assets
under the MEC Takeover Proposal should be considered. Arthur Andersen Economic
Consulting is a practice unit within Arthur Andersen LLP. Arthur Andersen LLP
has served as the independent accountants for IES, WPLH and MEC for many years,
performing the independent annual audit of the companies and providing business
advisory and tax consultation to the three companies. Arthur Andersen LLP has
received customary fees for these services.
    
 
   
    To assist the IES Board in its consideration of the MEC Takeover Proposal
and the Mergers, the IES Board requested that Morgan Stanley provide it with
information and analyses related thereto. Further to such requests, at the
August 14, 1996 IES Board meeting, Morgan Stanley presented information and
analyses consisting of the following: (i) an estimate of the nominal value of
the MEC Takeover Proposal as between $36.95 and $37.77 per share of IES Common
Stock on a pre-tax basis, based upon the closing price of MEC's common stock as
of August 13, 1996 and depending on the percentage of IES shares exchanged for
cash, compared with the nominal value of the Mergers to the holders of IES
Common Stock as between $31.69 and $39.72, based upon the closing price of WPLH
Common Stock as of August 13, 1996 and assuming various modified exchange ratios
for the IES Ratio; (ii) a comparison of certain financial implications of the
MEC Takeover Proposal and the Mergers, including the view that the Mergers
afforded the combined company with the opportunity to trade at a relatively
higher pro forma price to earnings multiple and would, in most cases, maintain a
lower pro forma dividend payout ratio, but would offer a lower pro forma
dividend per share increase, in each case, than would the MEC Takeover Proposal
if effectuated; (iii) an overview of selected business, financial and market
statistics for IES and MEC, including certain financial and operating
information taken from publicly available financial statements and reports of
each such companies, closing prices for the common stock of IES and MEC as of
August 13, 1996, securities research analysts consensus earnings estimates and
five-year earnings growth rates as reported by I/B/E/S, and senior corporate
credit ratings as reported by Standard & Poor's; (iv) an analysis of the trading
history of the common stock of each of IES and MEC, including the fact that MEC
had traded in a range between $13.75 and $18.75 per share since its initial
listing on July 3, 1995 following the merger forming MEC and that MEC stock had
underperformed on a relative basis as compared to IES
    
 
                                       5
<PAGE>
   
Common Stock during such period; (v) analyses of the pro forma ownership
interests of IES shareholders, ranging from approximately 29.4% to 41.0%, and
MEC shareholders, ranging from 59.0% to 70.6%, respectively, in a combined
company, assuming varying percentages of cash consideration to be paid by MEC to
effect the MEC Takeover Proposal; (vi) pro forma analyses of the earnings impact
of the MEC Takeover Proposal if effectuated to (a) holders of IES Common Stock,
which generated earnings accretion during the period 1997-1999 ranging from
26.8% to 52.1%, and (b) MEC shareholders, which yielded results during the
period 1997-1999 ranging from 19.8% dilution to 0.8% accretion, in each case,
based upon consensus estimates of securities research analysts as of July 18,
1996 and depending upon varying percentages of cash consideration to be paid by
MEC to effect the MEC Takeover Proposal, the levels, amount and timing of
synergies realized by the combined company and the financing and stock
repurchase strategies that were implemented (this analysis, which was provided
to the IES Board for background purposes, is relevant in assessing the ability
of MEC to obtain approval from its shareholders and in terms of how the future
trading value of MEC common stock might be adversely affected); (vii) a summary
analysis of the pro forma dividend impact per share if the MEC Takeover Proposal
were effectuated showing that holders of IES Common Stock would experience an
increase in dividends per share during the period 1997-1999 ranging from
approximately 31.6% to 34.1% over the projected IES stand-alone dividend level;
(viii) estimates of expected MEC pro forma 1998 per share values ranging from
$13.34 to $19.62, with the per share values at the lower end of such range being
more relevant based on the 1998 price to earnings multiple of MEC as of August
2, 1996 and August 13, 1996, based on sensitivity analyses performed using a
range of price to earnings multiples, varying percentages of cash consideration
to be paid by MEC to effectuate the MEC Takeover Proposal, the levels, amount
and timing of synergies realized by the combined company, and the financing and
stock repurchase strategies implemented; (ix) analyses of the pro forma
ownership interests of WPLH shareholders, ranging from approximately 39.8% to
43.0%, of IES shareholders, ranging from approximately 42.1% to 46.5%, and IPC
shareholders, ranging from 13.7% to 14.8%, respectively, if the Mergers were
consummated, based on various modified exchange ratios for the IES Ratio; (x)
pro forma analyses of the earnings impact of the Mergers to (a) holders of IES
Common Stock, which resulted in earnings accretion during 1998 ranging from 3.7%
to 30.0%, (b) holders of WPLH Common Stock, which in 1998 led to results ranging
from earnings dilution of 13.9% to earnings accretion of 5.4%, and (c) holders
of IPC Common Stock, which in 1998 generated earnings accretion ranging from
3.0% to 26.1%, in each case, based upon consensus estimates of securities
research analysts as of July 18, 1996 and using various modified exchange ratios
for the IES Ratio and varying levels of synergies realized by the combined
company; (xi) a summary analysis of the pro forma dividend impact per share of
the Mergers showing that holders of IES Common Stock would experience during the
period 1997-1999 results ranging from 4.0% dilution to 18.4% accretion, based on
various modified exchange ratios for the IES Ratio; (xii) estimates of expected
Interstate Energy pro forma 1998 per share values ranging from $25.62 to $33.93,
with the per share values at the higher end of such range being more relevant
based on the 1998 price to earnings multiple of WPLH as of August 2, 1996 and
August 13, 1996, based on sensitivity analyses performed using a range of price
to earnings multiples, various modified exchange ratios for the IES Ratio and
varying levels of synergies realized; and (xiii) pro forma financial ratios for
the MEC Takeover Proposal if effectuated, including latest twelve months
EBITDA/Total Interest Expense ranging between 3.7x-4.6x and Total Debt/Total
Book Capitalization ranging between 47.5% and 57.0%, in each case, depending on
the percentages of cash consideration to be paid by MEC in effectuating the MEC
Takeover Proposal, and the Mergers, including latest twelve months EBITDA/Total
Interest Expense of 5.2x and Total Debt/Total Book Capitalization of 47.4%.
Morgan Stanley assumed various modified exchange ratios for the IES Ratio for
purposes of performing its analyses as indicated above, since at August 14,
1996, it was not known whether the Board of Directors of WPLH and IPC would
approve an exchange ratio more favorable to IES than the ratio then in effect,
or what that exchange ratio would be. Morgan Stanley also presented (a) a
listing of the IES shareholdings showing the relative levels of institutional,
retail and insider/beneficial ownership and (b) a listing of certain other
electric utility transactions and comparative statistics derived therefrom.
    
 
                                       6
<PAGE>
    After discussion, the IES Board concluded that, from a strategic
perspective, the Mergers would be more beneficial to IES and its shareholders,
customers and employees and the communities that IES serves than the MEC
Takeover Proposal would be. The IES Board then asked Mr. Liu to speak again with
Mr. Stoppelmoor to suggest that the parties agree on an increase in the IES
Ratio beyond 1.11 to enhance further the probability that the IES shareholders
would approve the Merger Agreement. This conversation thereafter took place
wherein Mr. Stoppelmoor indicated to Mr. Liu that he believed an increase in the
IES Ratio by an unspecified amount over 1.11 might be possible. Mr. Stoppelmoor
also told Mr. Liu that WPLH and IPC had scheduled Board meetings for the next
day. The IES Board then reconvened and approved the change of control agreements
described in "Executive Change of Control Agreements" below. Following
consultations with representatives of WPLH and IPC and their respective
financial and legal advisors and a separate conversation between Mr. Davis and
Mr. Stoppelmoor, Mr. Stoppelmoor called Mr. Liu in the evening of August 14,
1996 to inform him that the managements of WPLH and IPC were prepared to
recommend to their respective Boards of Directors an increase in the IES Ratio
to 1.14.
 
    On August 15, 1996, the WPLH Board, at a special meeting, discussed with
WPLH's financial and legal advisors the MEC Takeover Proposal and the proposed
increase in the IES Ratio. Merrill Lynch discussed and reviewed with the WPLH
Board the proposed adjustment of the IES Ratio to 1.14 and orally confirmed that
Merrill Lynch would be prepared to render an opinion to the effect that, based
on the assumptions made, matters considered and limits of review set forth in
such opinion, the Ratios (including the IES Ratio as proposed to be adjusted)
are fair to WPLH from a financial point of view. At this meeting, counsel to
WPLH also described the proposed amendment to the Merger Agreement and discussed
with the WPLH Board legal issues relating to soliciting proxies for the WPLH
Meeting. The WPLH Board further discussed and affirmed the benefits of the
Mergers to WPLH and its shareowners, employees and customers and the communities
that it serves, as set forth in the Original Joint Proxy Statement/Prospectus
under the caption "The Mergers -- Reasons for the Mergers; Recommendations of
the Boards of Directors." After considering the presentations made and the
matters discussed at the meeting, the WPLH Board by the directors present
unanimously approved a proposal to amend the Merger Agreement to increase the
IES Ratio to 1.14.
 
    Also on August 15, 1996, at a special meeting of the IPC Board, the IPC
Board discussed with IPC's legal and financial advisors the MEC Takeover
Proposal and the proposed increase in the IES Ratio. Salomon Brothers discussed
and reviewed with the IPC Board the proposed adjustment of the IES Ratio and
orally confirmed that Salomon Brothers would be able to render an opinion to the
effect that, based on the assumptions made, matters considered and limits of
review set forth in such opinion, the IPC Ratio (assuming the increase for the
IES Ratio from 1.01 to 1.14) is fair from a financial point of view to the
holders of IPC Common Stock. The IPC Board further discussed and affirmed the
benefits of the Mergers to IPC and its shareholders, employees and customers and
the communities that it serves, as set forth in the Original Joint Proxy
Statement/Prospectus under the caption "The Mergers -- Reasons for the Mergers;
Recommendations of the Boards of Directors." IPC's legal advisors described the
proposed amendment to the Merger Agreement and discussed with the IPC Board
various other matters relating to the solicitation of proxies for the IPC
Meeting. After considering the presentations made and the matters discussed at
the meeting, the IPC Board unanimously approved a resolution to amend the Merger
Agreement to increase the IES Ratio to 1.14.
 
    At 6:00 p.m., Central time, on August 15, 1996, the IES Board held a
telephonic meeting. Mr. Liu informed the IES Board that WPLH and IPC had agreed
to increase the IES Ratio to 1.14, and the IES Board unanimously (with one
abstention by a director who was not eligible to vote on the matter) authorized
the execution and delivery by IES of an amendment to the Merger Agreement
effecting this change. The IES Board also determined unanimously (with one
abstention) to reject the MEC Takeover Proposal.
 
    The parties thereafter executed and delivered Amendment No. 2, dated as of
August 16, 1996, to the Merger Agreement, increasing the IES Ratio to 1.14.
 
                                       7
<PAGE>
   
    On August 21, 1996, a lawsuit described as a class action was filed against
IES, each of its directors and James E. Hoffman, its Executive Vice President.
The plaintiffs claim ownership of a total of 600 shares of IES Common Stock. The
lawsuit alleges breaches of fiduciary duties by the directors of IES for claimed
conflicts of interest and for allegedly failing to consider the MEC Takeover
Proposal adequately. The plaintiffs seek an order directing the named defendants
to negotiate in good faith with MEC; to undertake "an appropriate" evaluation of
the MEC Takeover Proposal; rescinding the Merger Agreement "to the extent
already implemented"; and providing certain ancillary relief. To IES's
knowledge, no order for certification of a class has issued, and the hearing
required for such an order has not yet been sought by plaintiffs. IES beleives
the suit is without merit. IES intends to oppose certification of a class and to
defend the lawsuit vigorously.
    
 
REASONS FOR THE MERGERS; RECOMMENDATIONS OF THE BOARDS OF DIRECTORS
 
    WPLH.  WPLH continues to believe that the Mergers offer significant
strategic and financial benefits to WPLH and its shareowners, as well as to its
employees and customers and the communities which it serves. These reasons are
summarized in the Original Joint Proxy Statement/Prospectus under the caption
"The Mergers -- Reasons for the Mergers; Recommendations of the Boards of
Directors."
 
    THE WPLH BOARD BY THE DIRECTORS PRESENT HAS UNANIMOUSLY APPROVED THE MERGER
AGREEMENT, AS AMENDED, AND BELIEVES THAT THE TERMS OF THE MERGERS ARE FAIR TO,
AND IN THE BEST INTERESTS OF, WPLH'S SHAREOWNERS, HAS APPROVED EACH OF THE WPLH
CHARTER AMENDMENTS DESCRIBED IN THE ORIGINAL JOINT PROXY STATEMENT/PROSPECTUS,
SUPPORTS THE ELECTION OF THE NOMINATED WPLH DIRECTORS AND SUPPORTS THE
APPOINTMENT OF ARTHUR ANDERSEN LLP AS WPLH'S INDEPENDENT AUDITORS FOR THE YEAR
ENDING DECEMBER 31, 1996. THE WPLH BOARD RECOMMENDS A VOTE FOR APPROVAL OF THE
MERGER AGREEMENT, AS AMENDED, FOR APPROVAL OF EACH OF THE WPLH CHARTER
AMENDMENTS, FOR THE ELECTION OF THE NOMINATED WPLH DIRECTORS AND FOR THE
RATIFICATION OF THE APPOINTMENT OF THE INDEPENDENT AUDITORS.
 
    IES.  For the reasons stated in the Original Joint Proxy
Statement/Prospectus under the caption "The Mergers -- Reasons for the Mergers;
Recommendations of the Boards of Directors" and for the reasons set forth below,
the IES Board believes that the terms of the Mergers, as amended, are fair to,
and in the best interests of, IES and its shareholders. Accordingly, the IES
Board, by a unanimous vote (with one abstention), has approved the Merger
Agreement, as amended, and the transactions contemplated thereby, recommends its
approval and adoption by IES's shareholders, and has rejected the MEC Takeover
Proposal.
 
   
    The IES Board believes that: (i) the IES Ratio offers IES shareholders an
attractive premium over the recent historical trading prices of IES Common
Stock, including a 22% premium (based on the closing price of WPLH Common Stock
on August 15, 1996) over the closing price of IES Common Stock on the New York
Stock Exchange (the "NYSE") on August 2, 1996 (the last full trading day prior
to the public announcement of the MEC Takeover Proposal); (ii) as shareholders
of Interstate Energy, IES shareholders will benefit more by participation in the
combined economic growth of the service territories of IES Utilities Inc.
("Utilities"), Wisconsin Power & Light Company ("WP&L") and IPC than IES
shareholders would benefit as shareholders of IES alone or in combination with
MEC, due to a higher expected growth rate in Utilities', WP&L's and IPC's
service territories than in MEC's service territory, and as evidenced by the
difference in the price to earnings ratios of WPLH and MEC stock; (iii) as
shareholders of Interstate Energy, IES shareholders will benefit more from the
inherent increase in economies of scale, the market and regulatory
diversification and the resulting increased financial stability and strength of
the combined entity than IES shareholders would benefit as shareholders of IES
alone or in combination with MEC, due in large measure to the difference in cost
and capital structures between WPLH and MEC and MEC's proposed plan for
financing the MEC Takeover Proposal; (iv) the Mergers will result in cost
savings from decreased electric production and gas supply costs, a reduction in
operating and maintenance expense and other factors discussed in the
    
 
                                       8
<PAGE>
   
Original Joint Proxy Statement/Prospectus in comparison with IES alone or in
combination with MEC, while the MEC Takeover Proposal would result in increased
average cost per kilowatt hour compared to IES alone or in combination with WPLH
and IPC; (v) in large part due to its expected lower cost structure and its
presence in several jurisdictions, Interstate Energy would be better able to
participate in the increasingly competitive market for the generation of power
than could IES alone or in combination with MEC; and (vi) the Mergers and
various provisions of the Merger Agreement offer IES shareholders, ratepayers
and employees a unique opportunity to realize the benefits created by combining
the three entities, due to the unprecedented combination of the service
territories of three strong neighboring utilities and the management succession
plan resulting therefrom. The IES Board believes that these factors offer a
potential increase in earnings in excess of those that could be achieved by IES
alone or in combination with MEC, and that the Mergers will result in the
creation of a financially stronger company.
    
 
   
    In reaching its conclusions, the IES Board considered (i) the original and
newly-adjusted IES Ratio and the fact that such ratios represent an 11% premium
and a 32% premium (based on the closing price of WPLH Common Stock on August 15,
1996), respectively, over the closing price of IES Common Stock on the NYSE on
November 10, 1995 (the last full trading day prior to the public announcement of
the Mergers) and premiums of approximately 14% and 37%, respectively, over the
closing price of IES Common Stock on the NYSE on October 10, 1995 (the trading
day that is 30 days prior to the date on which the Mergers were publicly
announced); (ii) the newly-adjusted IES Ratio represents a 22% premium (based on
the closing price of WPLH Common Stock on August 15, 1996) over the closing
price of IES Common Stock on the NYSE on August 2, 1996 (the last full trading
day prior to the public announcement of the MEC Takeover Proposal); (iii) the
financial performance (1995 revenue of $851 million, $807 million, $318.5
million and $1,723.6 million, respectively, and net income of $64.2 million,
$58.4 million, $27.7 million and $122.8 million, respectively), financial
condition, business operations, prospects and historical price to earnings ratio
(14.83, 13.51, 14.20 and 10.73 times estimated 1996 earnings, based on I/B/E/S
dated July 18, 1996 and closing stock prices as of August 15, 1996) of each of
IES, WPLH, IPC and MEC and that, on a combined basis, IES, WPLH and IPC will
likely have greater financial stability and strength than IES alone or in
combination with MEC due to participation in the combined economic climate and
growth of each of the Utilities, WP&L and IPC service territories, the inherent
increase in economies of scale, the market diversification resulting from the
combination of customer bases and the impact of the potential operating
efficiencies and other synergies which are expected to reduce operational and
maintenance expenses, as more fully discussed in the Original Joint Proxy
Statement/Prospectus; (iv) current industry, economic, market and regulatory
conditions which encourage consolidation to reduce risk and create new avenues
for earnings growth (as discussed under "The Mergers -- Background of the
Mergers" in the Original Joint Proxy Statement/Prospectus); (v) the prospects
for earnings and dividend growth of IES alone and in combination with MEC in
light of the pro forma percentage (44% in the case of the Mergers after the
increase in the IES Ratio, 29% in the case of the MEC Takeover Proposal,
assuming 40% of the consideration in the MEC Takeover Proposal is cash) of
estimated synergies ($749 million in the case of the Mergers, based upon a
report prepared jointly by WPLH, IES and IPC, and $500 million in the case of
the MEC Takeover Proposal, according to MEC's public filings (which amount MEC
has since increased to an amount in excess of $650 million)) that would inure to
the benefit of the holders of IES Common Stock, as well as the cost structures
of the respective combined companies; (vi) the recent levels of merger activity
involving electric utility companies in markets near Utilities' service
territory and the ability of IES alone or in combination with MEC to remain
competitive over the long-term; (vii) the anticipated positive effect of the
Mergers on IES's shareholders and Utilities' customers, including maintaining
competitiveness, integrating corporate and administrative functions and reducing
operating costs, particularly as compared with the MEC Takeover Proposal (all as
more fully described above and in the Original Joint Proxy
Statement/Prospectus); (viii) the terms of the Merger Agreement, the Stock
Option Agreements, the Employment Agreements and other documents executed and to
be executed in connection with the Mergers which provide for reciprocal
representations and warranties, conditions to closing and rights to termination,
and balanced rights
    
 
                                       9
<PAGE>
   
and obligations; (ix) the management succession plan specified in the Merger
Agreement and the Employment Agreements of Messrs. Liu, Davis, Stoppelmoor and
Chase (as described under "The Mergers -- Employment Agreements" and "Interstate
Energy Following the Mergers -- Management of Interstate Energy" in the Original
Joint Proxy Statement/Prospectus) which provides a plan for managing the
integration of and transition in management; (x) the impact of regulation under
various state and federal laws (as described under "Regulatory Matters" and "The
Mergers -- Background of the Mergers" in the Original Joint Proxy
Statement/Prospectus); (xi) that the Mergers are expected to be treated as
tax-free reorganizations to shareholders and to be accounted for as a
pooling-of-interests transaction (which avoids the reduction in earnings which
would result from increased depreciation associated with the write-up of asset
values, and the creation and amortization of goodwill, under purchase
accounting); (xii) equivalent annual dividends per share of Interstate Energy
Common Stock which are expected to be approximately 15 cents or 7% higher than
the current annualized dividends which have been paid on IES Common Stock;
(xiii) the risk that MEC might not be able to obtain its own shareholders'
approval for the MEC Takeover Proposal in light of the potential substantial
earnings dilution that would be experienced by MEC shareholders, as well as the
risk that MEC might not be able to obtain regulatory approval for a transaction
with significant consequences within Iowa; and (xiii) the opinion of Morgan
Stanley, described below, that the IES Ratio, taking into account the IPC Ratio,
is fair from a financial point of view to the holders of IES Common Stock. The
IES Board did not rely on Morgan Stanely's opinion in determining that the
strategic benefits of the Mergers were more favorable to IES, its shareholders
and its other constituencies than those which could be realized in the MEC
Takeover Proposal. The IES Board believed that the strategic benefits of the
Mergers outweighed the apparent differences in immediate shareholder value which
would be higher for the MEC Takeover Proposal. The IES Board determined it to be
reasonable to rely on the Morgan Stanley opinion in respect of the fariness of
the Mergers to the holders of IES Common Stock, as stated in Morgan Stanely's
opinion, because of Morgan Stanley's recognized expertise in financial analysis,
its history of providing opinions as to the fairness of other transactions and
the comprehensive analysis upon which its opinion was based. Moreover, under
Section 490.1108 of the Iowa Business Corporation Act, the IES Board was
entitled to consider, in addition to the interests of IES and its shareholders,
the effects of the MEC Takeover Proposal on IES's employees, suppliers,
creditors and customers; the effects of the MEC Takeover Proposal on the
communities in which IES operates; and the long-term as well as the short-term
interests of IES and its shareholders, including the possibility that these
interests may be best served by the continued independence of IES. Moreover, the
IES Board obtained advice from its legal counsel as to its fiduciary obligations
in connection with its consideration of the relative benefits to IES
shareholders and IES's other constituencies, which could be derived from the
Mergers compared to the MEC Takeover Proposal. The IES Board recognized that,
(a) the consideration offered by MEC in the MEC Takeover Proposal may be valued
at a greater amount than the value of the consideration to be received in the
Mergers, (b) although annual dividends per share of Interstate Energy Common
Stock are expected to be higher than those which have been paid on IES Common
Stock, such dividends would be approximately 20% less than the annual dividends
per share that MEC claims would be paid under the MEC Takeover Proposal, and (c)
IES combined with MEC would be a larger company than Interstate Energy would be.
Although the IES Board recognized the negative factors discussed in this
paragraph are not immaterial, the IES Board believes considerations favoring the
Mergers, together with the advice or assistance of its financial advisor and
consultants as described herein, substantially outweigh any negatives and the
terms of the Mergers are, as a whole, in the best interests of IES and its
shareholders. The IES Board believes that the difference in the value of the
consideration between the MEC Takeover Proposal and the Mergers is not
significant enough to justify terminating the Mergers, which the IES Board
believes provide greater strategic benefits than the MEC Takeover Proposal. The
IES Board further believes that, although MEC has projected that it will be able
to maintain its promised dividend rate, MEC might not be able to do so if it is
not able to sell assets sufficiently quickly or to realize enough from asset
sales to reduce the debt it would incur to complete the MEC Takeover Proposal.
Finally, the IES Board believes that the quality of management and a shared
strategic vision is more important in the creation of a low-cost energy producer
able to meet the
    
 
                                       10
<PAGE>
   
challenges arising from an expansion of competition in the utility business than
size alone. In determining that the Mergers are fair to and in the best
interests of shareholders, the IES Board considered the above factors as a whole
and did not assign specific or relative weights to any one factor or group of
factors.
    
 
    THE IES BOARD HAS APPROVED THE MERGER AGREEMENT, AS AMENDED, BY UNANIMOUS
VOTE (WITH ONE ABSTENTION) AND BELIEVES THAT THE TERMS OF THE MERGERS ARE FAIR
TO, AND IN THE BEST INTERESTS OF, IES'S SHAREHOLDERS, AND SUPPORTS THE ELECTION
OF THE NOMINATED IES DIRECTORS. THE IES BOARD RECOMMENDS A VOTE FOR APPROVAL OF
THE MERGER AGREEMENT, AS AMENDED, AND FOR THE ELECTION OF THE NOMINATED IES
DIRECTORS.
 
    IPC.  IPC continues to believe that the Mergers offer significant strategic
and financial benefits to IPC and its stockholders, as well as to its employees
and customers. These reasons are summarized in the Original Joint Proxy
Statement/Prospectus under the caption "The Mergers -- Reasons for the Mergers;
Recommendations of the Boards of Directors."
 
    THE IPC BOARD HAS UNANIMOUSLY APPROVED THE MERGER AGREEMENT, AS AMENDED, AND
BELIEVES THAT THE TERMS OF THE MERGERS ARE FAIR TO, AND IN THE BEST INTERESTS
OF, IPC'S STOCKHOLDERS, HAS UNANIMOUSLY ADOPTED A RESOLUTION SETTING FORTH THE
IPC CHARTER AMENDMENT AND DECLARING ITS ADVISABILITY, AND SUPPORTS THE ELECTION
OF THE NOMINATED IPC DIRECTORS. THE IPC BOARD RECOMMENDS A VOTE FOR APPROVAL OF
THE MERGER AGREEMENT, AS AMENDED, FOR APPROVAL OF THE IPC CHARTER AMENDMENT AND
FOR THE ELECTION OF THE NOMINATED IPC DIRECTORS.
 
OPINIONS OF FINANCIAL ADVISORS
 
   
    WPLH'S FINANCIAL ADVISOR.  Merrill Lynch has delivered to the WPLH Board its
written opinion dated August 21, 1996 to the effect that, as of such date, and
based upon the assumptions made, matters considered and limits of review as set
forth in such opinion, the Ratios are fair, from a financial point of view, to
WPLH. On August 15, 1996, at a special meeting of the WPLH Board, Merrill Lynch
discussed and reviewed with the WPLH Board the proposed adjustment of the IES
Ratio to 1.14 (the "Adjusted IES Ratio"). The following is a summary of all of
the analyses that Merrill Lynch performed in connection with the Adjusted IES
Ratio.
    
 
   
    Merrill Lynch compared the financial terms and related impact on WPLH
shareowners of the Merger Agreement, as amended as of May 22, 1996, to the terms
of the proposed amendment to the Merger Agreement. In this regard, Merrill Lynch
compared the overall aggregate percentage pro forma ownership of the combined
company assuming the Mergers were consummated at the Ratios (assuming the IES
Ratio was 1.01 (the "Old IES Ratio")) to the Adjusted IES Ratio as follows: (i)
the holders of WPLH Common Stock would own 43.0% of the combined company
(assuming the Old IES Ratio) compared to 40.8% of the combined company (assuming
the Adjusted IES Ratio), (ii) the holders of IES Common Stock would own 42.0% of
the combined company (assuming the Old IES Ratio) compared to 45.0% of the
combined company (assuming the Adjusted IES Ratio), and (iii) the holders of IPC
Common Stock would own 14.9% of the combined company (assuming the Old IES
Ratio) compared to 14.2% of the combined company (assuming the Adjusted IES
Ratio). Merrill Lynch also analyzed the payout ratio of dividends to earnings
for the combined company and WPLH using the projected earnings for the years
1997 through 1999 provided by the respective managements of WPLH, IES and IPC
(the "Projections"). This analysis resulted in amounts equal to approximately
82.8% in 1997, 78.1% in 1998 and 76.5% in 1999 for the combined company on a pro
forma basis compared to 78.7% in 1997, 79.4% in 1998 and 77.4% in 1999 for WPLH
on a stand-alone basis. Merrill Lynch summarized the MEC Takeover Proposal and
compared such proposal to the IES Ratio and to the Adjusted IES Ratio. Merrill
Lynch reviewed the performance of the per share market price of IES Common Stock
and WPLH Common Stock during the period from November 10, 1995 through August
14, 1996 and calculated the ratio of the per share market price of IES Common
Stock to the per
    
 
                                       11
<PAGE>
   
share market price of WPLH Common Stock during this period and compared such
result to the Adjusted IES Ratio. In addition, Merrill Lynch compared the
results of its analyses performed in connection with the opinion of Merrill
Lynch rendered on November 10, 1995, as adjusted by the increase in the McLeod,
Inc. ("McLeod") valuation referred to below, to the Adjusted IES Ratio. This
comparison confirmed that the Adjusted IES Ratio was within the ranges
calculated for each of the following analyses: (i) comparable publicly traded
company analysis, (ii) contribution analysis, (iii) dividend discount analysis,
(iv) discounted cash flow analysis and (v) comparable acquisition transaction
analysis, in each case assuming a discount off of the public market trading
value of McLeod shares on August 14, 1996. Merrill Lynch noted to the WPLH Board
that (i) Merrill Lynch originally valued IES's equity interest in McLeod at book
value, which was approximately $10.0 million in November 1995, to arrive at the
opinion of Merrill Lynch rendered on November 10, 1995 and (ii) that on June 14,
1996, McLeod consummated its initial public offering. Merrill Lynch calculated
IES's equity interest in McLeod based on the public trading market of McLeod on
August 14, 1996 to be approximately $252.2 million. Merrill Lynch calculated the
net increase in the value of each IES share based solely on the increase in the
value of IES owned shares of McLeod by comparing the initial McLeod valuation
with the current trading value of McLeod at 100% and 70% of the public market
trading value of McLeod shares as of August 14, 1996. Such calculation resulted
in a net increase in the value of each IES share of $8.47 and $5.83, assuming
100% and 70%, respectively, of the public market trading value of McLeod shares
as of August 14, 1996. Merrill Lynch also analyzed the earnings per share
accretion/dilution of WPLH Common Stock using the Projections and assuming
certain synergies for the combined company provided by WPLH management. This
analysis indicated that the Old IES Ratio would be accretive to WPLH shareowners
in amounts of 0.4% in 1997, 7.4% in 1998 and 7.1% in 1999, and the Adjusted IES
Ratio would be dilutive to WPLH shareowners in the amount of 4.9% in 1997 and
accretive to WPLH shareowners in the amounts of 1.6% in 1998 and 1.2% in 1999.
Merrill Lynch noted to the WPLH Board that compared to the Old IES Ratio, the
Adjusted IES Ratio would produce earnings per share which are dilutive to WPLH
shareowners in 1997, and less accretive in 1998 and 1999. However, in light of
the increased value of McLeod and the results of all of the analyses performed
by Merrill Lynch, Merrill Lynch concluded that the Ratios (including the
Adjusted IES Ratio) are fair, from a financial point of view, to WPLH.
    
 
   
    The summary set forth above does not purport to be a complete description of
the analyses performed by Merrill Lynch in arriving at the August 21, 1996
opinion.
    
 
   
    A COPY OF THE AUGUST 21, 1996 OPINION OF MERRILL LYNCH, WHICH SETS FORTH THE
ASSUMPTIONS MADE, MATTERS CONSIDERED AND CERTAIN LIMITATIONS ON THE SCOPE OF
REVIEW UNDERTAKEN BY MERRILL LYNCH, IS ATTACHED AS ANNEX II TO THIS SUPPLEMENT
TO THE JOINT PROXY STATEMENT/PROSPECTUS. WPLH SHAREOWNERS ARE URGED TO READ SUCH
OPINION IN ITS ENTIRETY. THE AUGUST 21, 1996 OPINION OF MERRILL LYNCH IS
DIRECTED ONLY TO THE FAIRNESS OF THE RATIOS FROM A FINANCIAL POINT OF VIEW AND
DOES NOT CONSTITUTE A RECOMMENDATION TO ANY WPLH SHAREOWNER AS TO HOW SUCH
SHAREOWNER SHOULD VOTE AT THE WPLH MEETING. REFERENCES TO THE AUGUST 21, 1996
OPINION OF MERRILL LYNCH SET FORTH HEREIN ARE QUALIFIED IN THEIR ENTIRETY BY
REFERENCE TO THE FULL TEXT OF SUCH OPINION ATTACHED AS ANNEX II HERETO.
    
 
   
    IES'S FINANCIAL ADVISOR.  On August 14, 1996, at a meeting of the IES Board,
Morgan Stanley discussed and reviewed with the IES Board the proposed adjustment
to the IES Ratio and rendered to the IES Board an oral opinion to the effect
that, as of such date, and based on the procedures and subject to the
assumptions stated at such August 14, 1996 IES Board meeting, and in the opinion
dated the date of this Supplement to Joint Proxy Statement/Prospectus, which is
attached hereto as Annex III, the IES Ratio (as adjusted to 1.14), taking into
account the IPC Ratio, is fair from a financial point of view. In a written
opinion dated the date hereof, Morgan Stanley confirmed its August 14, 1996 oral
opinion.
    
 
    THE FULL TEXT OF MORGAN STANLEY'S WRITTEN OPINION DATED THE DATE HEREOF,
WHICH SETS FORTH THE ASSUMPTIONS MADE, MATTERS CONSIDERED AND LIMITATIONS ON THE
REVIEW UNDERTAKEN, IS ATTACHED AS ANNEX III TO THIS SUPPLEMENT TO JOINT PROXY
STATEMENT/PROSPECTUS AND IS INCORPORATED HEREIN BY REFERENCE. HOLDERS OF IES
COMMON STOCK ARE URGED TO, AND SHOULD, READ THIS OPINION CAREFULLY IN ITS
ENTIRETY. MORGAN STANLEY'S
 
                                       12
<PAGE>
OPINION ADDRESSES ONLY THE FAIRNESS OF THE IES RATIO (AS ADJUSTED), TAKING INTO
ACCOUNT THE IPC RATIO, FROM A FINANCIAL POINT OF VIEW TO THE HOLDERS OF IES
COMMON STOCK, AND IT DOES NOT ADDRESS ANY OTHER ASPECT OF THE MERGERS NOR DOES
IT CONSTITUTE A RECOMMENDATION TO ANY HOLDER OF IES COMMON STOCK AS TO HOW TO
VOTE AT THE IES MEETING. THE SUMMARY OF THE OPINION OF MORGAN STANLEY SET FORTH
IN THIS SUPPLEMENT TO JOINT PROXY STATEMENT/PROSPECTUS IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO THE FULL TEXT OF SUCH OPINION.
 
   
    In rendering its opinion, Morgan Stanley assumed and relied upon without
independent verification the accuracy and completeness of the information
reviewed by Morgan Stanley for the purposes of its opinion. With respect to the
financial projections and the estimates of potential cost savings to be derived
from the Mergers, Morgan Stanley assumed that such projections and estimates
were reasonably prepared on bases reflecting the best currently available
estimates and judgments of the future financial performance of each of IES, WPLH
and IPC, respectively, and of the amount and timing of such cost savings. Morgan
Stanley also relied upon, with the consent of IES, IES's assessment of the
strategic and other benefits of the Mergers. Morgan Stanley did not make any
independent valuation or appraisal of the assets or liabilities of IES, WPLH and
IPC. In addition, Morgan Stanley, in rendering its opinion dated as of the date
of this Supplement to the Joint Proxy Statement/Prospectus, did not address the
relative merits of the Mergers and the MEC Takeover Proposal or any other
alternative potential transactions. In arriving at its opinion, Morgan Stanley
assumed that in connection with the receipt of all the necessary regulatory and
governmental approvals for the proposed Mergers, no restriction will be imposed
that would have a material adverse effect on the contemplated benefits expected
to be derived in the proposed Mergers. Morgan Stanley also assumed that the
Mergers will be consummated in accordance with the terms set forth in the Merger
Agreement, including, among other things, that the Mergers will be accounted for
as a "pooling-of-interests" business combination in accordance with United
States generally accepted accounting principles and that the Mergers will be
treated as a tax-free reorganization and/or exchange, in each case, pursuant to
the Code. Morgan Stanley's opinion is necessarily based on economic, market and
other conditions as in effect on, and the information made available to it as
of, the date of its opinion.
    
 
   
    In addition, Morgan Stanley was not authorized to solicit, and did not
solicit, interest from any party with respect to a merger with or other business
combination transaction involving IES, or any of its assets, nor did Morgan
Stanley have any discussions or negotiations with any parties, other than WPLH
and IPC, in connection with the Mergers.
    
 
    In connection with its opinion dated as of the date of this Supplement to
Joint Proxy Statement/ Prospectus, Morgan Stanley confirmed the appropriateness
of its reliance on the analyses used to render its November 10, 1995 oral
opinion and its July 11, 1996 written opinion by performing procedures to update
certain of such analyses and by reviewing the asssumptions upon which such
analyses were based and the factors considered in connection therewith. In
arriving at this opinion, Morgan Stanley, in addition to the aforementioned
procedures, performed certain analyses which were reviewed by the IES Board in
connection with the delivery of its opinion dated the date hereof, which are
briefly summarized as follows:
 
    PRO FORMA OWNERSHIP.  Morgan Stanley compared the overall aggregate
percentage share ownership of the combined company assuming the Mergers were
consummated at the prior exchange ratios (assuming the previous IES Ratio of
1.01) and at the IES Ratio (as adjusted to 1.14): (i) the holders of IES Common
Stock would own approximately 45.1% of the combined company pursuant to the
adjusted IES Ratio as compared to 42.1% of the combined company pursuant to the
previous exchange ratio, (ii) the holders of WPLH Common Stock would own
approximately 40.8% of the combined company pursuant to the adjusted IES Ratio
as compared to 43.0% of the combined company pursuant to the previous exchange
ratio and (iii) the holders of IPC Common Stock would own approximately 14.1% of
the combined company pursuant to the adjusted IES Ratio as compared to 14.9% of
the combined company pursuant to the previous exchange ratio.
 
    UPDATED PRO FORMA ANALYSIS OF THE MERGERS.  Morgan Stanley analyzed the pro
forma impact, taking into account the impact of the upward adjustment to the IES
Ratio of the Mergers on IES
 
                                       13
<PAGE>
   
earnings per share for the fiscal years ended 1997 through 1999. Such analysis
was performed utilizing stand-alone earnings estimated for the fiscal years
ended 1997 through 1999 for IES, WPLH and IPC based on an updated compilation of
earnings projections by securities research analysts, taking into account the
cost savings expected to be derived from the Mergers as estimated by the
managements of IES, WPLH and IPC. Based on the IES Ratio, earnings accretion to
holders of IES Common Stock during the period 1997-1999 ranged from 9.2% to
26.3%.
    
 
    The preparation of a fairness opinion is a complex process and is not
necessarily susceptible to a partial analysis or summary description. Morgan
Stanley believes that its analyses must be considered as a whole and that
selecting portions of its analyses, without considering all analyses, would
create an incomplete view of the process underlying its opinion. In addition,
Morgan Stanley may have given various analyses more or less weight than other
analyses, and may have deemed various assumptions more or less probable than
other assumptions, so that the ranges of valuations resulting for any particular
analysis described above should not be taken to be Morgan Stanley's view of the
actual value of IES, WPLH and IPC.
 
    In performing its analyses, Morgan Stanley made numerous assumptions with
respect to industry performance, general business and economic conditions and
other matters, many of which are beyond the control of IES, WPLH and IPC. The
analyses performed by Morgan Stanley are not necessarily indicative of actual
value, which may be significantly more or less favorable than suggested by such
analyses. Such analyses were prepared solely as part of Morgan Stanley's
analysis of the fairness of the IES Ratio, taking into account the IPC Ratio,
from a financial point of view to the holders of IES Common Stock and were
provided to the IES Board in connection with the delivery of Morgan Stanley's
written opinion dated the date hereof confirming its oral opinion of August 14,
1996. The analyses do not purport to be appraisals or to reflect the prices at
which IES, WPLH and IPC might actually be sold. Because such estimates are
inherently subject to uncertainty, none of IES, Morgan Stanley, or any other
person assumes responsibility for their accuracy. In addition, as described
above, Morgan Stanley's opinion and presentation to the IES Board was one of
many factors taken into consideration by the IES Board in making its
determination to approve the Mergers. Consequently, the Morgan Stanley analyses
described above should not be viewed as determinative of the opinion of the IES
Board or the view of management of either WPLH or IPC with respect to the value
of WPLH and IPC or of whether the IES Board or the managements of WPLH and IPC
would have been willing to agree to a different exchange ratio.
 
    In addition to its retention to act as financial advisor with respect to the
Mergers, Morgan Stanley has been retained by IES to act as financial advisor
with respect to the MEC Takeover Proposal. Pursuant to a letter agreement dated
as of August 4, 1996 between IES and Morgan Stanley, Morgan Stanley is entitled
to (a) an advisory fee for advising IES in the amount of $1,250,000, which is
payable as of the date of this Supplement to Joint Proxy Statement/Prospectus,
and (b) a transaction fee based upon the Aggregate Value (as such term is
defined in such letter agreement) of any consummated Acquisition Transaction (as
such term is defined in such letter agreement, which excludes the Mergers),
which fee will be a varying percentage of such Aggregate Value, decreasing from
0.450% of the aggregate value for an Acquisition Transaction having a value of
$1 billion, to 0.426% of the Aggregate Value for an Acquisition Transaction
having a value of $1.4 billion or more. The amount paid or payable to Morgan
Stanley as an advisory fee will be credited against the transaction fee.
 
   
    IPC'S FINANCIAL ADVISOR.  On August 15, 1996, at a meeting of the IPC Board,
Salomon Brothers reviewed with the IPC Board the proposed increase to the IES
Ratio from 1.01 to 1.14 and the financial impact of the proposed amendment to
the Merger Agreement on the holders of IPC Common Stock. Salomon Brothers
reviewed with the IPC Board the terms of the MEC Takeover Proposal and compared
such terms to those terms contemplated by the Merger Agreement and the proposed
amendment thereto. Salomon Brothers estimated the value of the MEC Takeover
Proposal to be approximately $37.95 per share of IES Common Stock, assuming
closing stock prices as of August 14, 1996 and 40% cash consideration. Salomon
Brothers compared the results of its analyses, as adjusted to give effect to the
increase in the valuation of McLeod, with the results of its analyses performed
in
    
 
                                       14
<PAGE>
   
connection with its opinion rendered on November 10, 1995. Salomon Brothers
calculated the net increase in the value of each share of IES Common Stock by
comparing the initial valuation of McLeod with a range of trading values for
McLeod, which range included the closing stock price for McLeod as of August 14,
1996. Such calculations resulted in a range of incremental after-tax value
attributable to IES Common Stock of $3.80 to $5.91 per share. Salomon Brothers
noted that such range of incremental value attributable to the IES-owned shares
of McLeod supported the proposed increase to the IES Ratio, and that such range
of incremental value would be attributable to the combined company, and
therefore attributable to the value of common stock of the combined company to
be received by holders of IPC Common Stock, assuming the Mergers were
consummated as of August 14, 1996. Salomon Brothers reviewed the results of its
analyses which were prepared in connection with its opinion rendered on November
10, 1995, which analyses related to the prices of the common stock of each of
IPC, WPLH and IES immediately prior to the initial announcement of the Mergers.
Salomon Brothers also noted that, assuming the Mergers were consummated at the
revised Ratios, the former holders of IPC Common Stock would own 14.1% of the
combined company, which compared to 14.9% of the combined company based upon the
Ratios presented at the meeting of the IPC Board on May 10, 1996. Further,
Salomon Brothers reviewed with the Board an updated pro forma analysis of merger
consequences to reflect the proposed increase to the IES Ratio. In addition to
the analyses set forth above, Salomon Brothers updated all of its analyses set
forth on pages 65-68 of the Original Joint Proxy Statement/Prospectus to reflect
the proposed increase to the IES Ratio. However, since such updated analyses did
not adversely affect Salomon Brothers' opinion as to the fairness of the IPC
Ratio, Salomon Brothers did not review the results of such updated analyses with
the IPC Board. Salomon Brothers advised the IPC Board that if the proposed
amendment to the Merger Agreement to give effect to the proposed increase to the
IES Ratio were entered into, Salomon Brothers would be able to render an opinion
to the effect that, based upon and subject to various considerations that would
be set forth in such opinion, the IPC Ratio (assuming the increase to the IES
Ratio from 1.01 to 1.14) is fair from a financial point of view to the holders
of IPC Common Stock (other than WPLH, IES or any of their respective
affiliates). In addition, Salomon Brothers has delivered to the IPC Board its
written opinion, dated August 21, 1996, to the effect that, based upon and
subject to various considerations set forth in such opinion, as of such date,
the IPC Ratio is fair from a financial point of view to the holders of IPC
Common Stock (other than WPLH, IES or any of their respective affiliates).
    
 
    THE FULL TEXT OF SALOMON BROTHERS' OPINION DATED THE DATE OF THIS SUPPLEMENT
TO JOINT PROXY STATEMENT/ PROSPECTUS, WHICH SETS FORTH THE ASSUMPTIONS MADE,
GENERAL PROCEDURES FOLLOWED, MATTERS CONSIDERED AND LIMITS ON THE REVIEW
UNDERTAKEN, IS ATTACHED AS ANNEX IV TO THIS SUPPLEMENT TO JOINT PROXY STATEMENT/
PROSPECTUS AND IS INCORPORATED HEREIN BY REFERENCE. SALOMON BROTHERS' OPINIONS
ARE DIRECTED ONLY TO THE FAIRNESS, FROM A FINANCIAL POINT OF VIEW, TO THE IPC
STOCKHOLDERS OF THE IPC RATIO AND DO NOT ADDRESS IPC'S UNDERLYING BUSINESS
DECISION TO ENTER INTO THE MERGERS OR CONSTITUTE A RECOMMENDATION TO ANY IPC
STOCKHOLDER AS TO HOW SUCH STOCKHOLDER SHOULD VOTE WITH RESPECT TO THE MERGER
AGREEMENT, AS AMENDED. THE SUMMARY OF SALOMON BROTHERS' OPINION SET FORTH ABOVE
IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE FULL TEXT OF SALOMON BROTHERS'
OPINION DATED THE DATE OF THIS SUPPLEMENT TO JOINT PROXY STATEMENT/PROSPECTUS
ATTACHED AS ANNEX IV HERETO. IPC STOCKHOLDERS ARE URGED TO, AND SHOULD, READ THE
OPINION CAREFULLY AND IN ITS ENTIRETY. THE OPINION DATED THE DATE OF THIS
SUPPLEMENT TO JOINT PROXY STATEMENT/PROSPECTUS IS SUBSTANTIALLY SIMILAR TO THE
SALOMON BROTHERS' OPINIONS DATED NOVEMBER 10, 1995 AND JULY 11, 1996.
 
THE MERGER AGREEMENT
 
    The parties have executed and delivered Amendment No. 2 to the Merger
Agreement, dated as of August 16, 1996, a copy of which is attached hereto as
Annex I. The only substantive change effected by Amendment No. 2 was to increase
the IES Ratio to 1.14. The other terms of the Merger Agreement as in effect
prior to Amendment No. 2 are summarized in the Original Joint Proxy Statement/
Prospectus under the caption "The Merger Agreement" and such Merger Agreement is
attached as Annex A to the Original Joint Proxy Statement/Prospectus.
 
                                       15
<PAGE>
    On August 15, 1996, the last full trading day before the public announcement
of an agreement in principle to increase the IES Ratio to 1.14, the high, low
and closing sales prices per share of (i) WPLH Common Stock on the NYSE were
$31 3/4, $31 1/2 and $31 3/4, respectively, (ii) IES Common Stock on the NYSE
were $33 3/8, $33 and $33 3/8, respectively, and (iii) IPC Common Stock on the
NYSE were $31 1/2, $31 1/4 and $31 1/4, respectively. Accordingly, if the
Mergers had been consummated on that date, each share of IES Common Stock would
have been converted into the right to receive 1.14 shares of WPLH Common Stock
having a market value of $36.20 based upon the closing price per share of WPLH
Common Stock on such date and each share of IPC Common Stock would have been
converted into the right to receive 1.11 shares of WPLH Common Stock having a
market value of $35.24 based on the closing price per share of WPLH Common Stock
on that date.
 
    Based on the capitalization of WPLH, IES and IPC on August 15, 1996 and the
Ratios (including the IES Ratio of 1.14), holders of WPLH Common Stock, IES
Common Stock and IPC Common Stock would have held approximately 40.8%, 45.1% and
14.1%, respectively, of Interstate Energy Common Stock that would have been
outstanding if the Mergers had been consummated as of such date.
 
EXECUTIVE CHANGE OF CONTROL AGREEMENTS
 
    The Original Joint Proxy Statement/Prospectus describes certain existing
severance agreements with IES executives, which include amendments to those
agreements approved by IES in November 1995. The severance agreements as so
amended provide salary continuation and other benefits in the event the
executive is terminated during the period beginning 180 days prior to a change
of control of IES and ending three years after the date of the change of
control. The Mergers will constitute a change of control for purposes of each of
these severance agreements.
 
   
    On August 14, 1996, the IES Board approved special change of control
severance agreements with fourteen of the Company's executives, including Mr.
Liu, James E. Hoffman and John F. Franz, Jr. The special severance agreements
would not apply in the event the Mergers are consummated (the existing severance
agreements would remain in place for this purpose), but would apply in the event
IES experiences another type of change of control, including, but not limited to
the transaction contemplated by the MEC Takeover Proposal. Specifically, the
special severance agreements define a "change of control" to mean any of the
following events: (i) an acquisition of 20% or more of IES's voting stock by any
person, entity or group acting together; (ii) individuals who, at the time the
special severance agreements are entered into, constitute the IES Board (the
"Incumbent Board") cease for any reason to constitute at least a majority of the
IES Board, except that individuals whose election to the IES Board is approved
by a majority of the Incumbent Board shall be considered to be members of the
Incumbent Board for this purpose; (iii) shareholder approval of a merger in
which IES is not the surviving entity (other than the Mergers); (iv) shareholder
approval of a sale of all or substantially all of the assets of IES; and (v)
shareholder approval of a liquidation or dissolution of IES. The special
severance agreements were approved partly in response to the MEC Takeover
Proposal but were also intended to apply to transactions involving any other
potential acquiror that meets the above definition of "change of control" (other
than the Mergers).
    
 
   
    The special severance agreements are identical to the existing severance
agreements in defining the types of terminations of employment that will trigger
salary and benefit continuation, and the period during which such terminations
have to occur (I.E., the period beginning 180 days prior to a change of control
and ending three years after the change of control). The specific levels of
salary and benefit continuation and other benefit entitlements provided under
the special severance agreements are identical to those provided under the
existing severance agreements, except for the following changes. Salary and
benefit continuation would be provided for a period ranging from twenty-four to
thirty-six months (Mr. Liu's continuation period would remain unchanged at
thirty-six months, while the continuation period for Messrs. Hoffman and Franz
would increase from eighteen to twenty-four months). In addition, there are
certain changes regarding executives with supplemental retirement plan ("SERP")
benefits. The special severance agreements would provide Mr. Liu with the same
level of SERP benefits as would be provided in the Employment Agreement to be
executed between Mr. Liu
    
 
                                       16
<PAGE>
   
and Interstate Energy in connection with the Mergers. Under that Employment
Agreement, Mr. Liu's SERP payments would be based on 75% of the sum of his
annual base salary and average annual bonus during the preceding three years (as
opposed to 75% of annual base salary under his existing severance agreement),
and in the event of Mr. Liu's death, payments would be guaranteed for a period
of 180 months (as opposed to 120 months under his existing severance agreement).
Other executives who are under age 56 with at least ten years of service at the
time of the change of control would be entitled to the same SERP benefits as
executives age 56 or older (under the existing severance agreements, all
executives who are under age 56 forfeit their SERP benefits and receive instead
a tax-deferred annuity). Mr. Franz is over age 56 and his SERP benefits would
not change. Mr. Hoffman is under age 56 with less than ten years of service, and
thus would receive only a tax-deferred annuity purchased with a cash amount
equal to twelve months of salary, an increase from six months under the original
agreement.
    
 
   
    If all fourteen of the executives covered by the special severance
agreements were involuntarily terminated in 1996 following a change in control,
the approximate cost in present value terms of the additional benefits provided
under the special severance agreements (as compared to the existing severance
agreements) would be less than $1.3 million. The special severance agreements
thus would not have a significant anti-takeover effect. IES believes that the
special severance agreements and the existing severance agreements enable IES to
employ key executives who can approach major business decisions objectively and
without concern for their personal situations.
    
 
                                       17
<PAGE>
COMPARATIVE BOOK VALUES, DIVIDENDS AND EARNINGS PER COMMON SHARE
 
    The following sets forth certain data on a historical and equivalent pro
forma basis giving effect to the Mergers and providing for the IES Ratio of 1.14
and the IPC Ratio of 1.11.
 
<TABLE>
<CAPTION>
                                                                                          JUNE 30,      DECEMBER 31,
                                                                                            1996            1995
                                                                                       ---------------  -------------
<S>                                                                                    <C>              <C>
BOOK VALUES PER COMMON SHARE
  WPLH/Interstate Energy
    Historical (6)...................................................................     $   19.99       $   19.41
    Equivalent pro forma (6).........................................................     $   18.82       $   18.64
  IES
    Historical.......................................................................     $   20.51       $   20.75
    Equivalent pro forma (1)(6)......................................................     $   21.45       $   21.25
  IPC
    Historical.......................................................................     $   20.95       $   20.68
    Equivalent pro forma (1)(6)......................................................     $   20.89       $   20.69
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                                   YEAR ENDED DECEMBER 31,
                                                                               TWELVE MONTHS
                                                                                   ENDED       -------------------------------
                                                                               JUNE 30, 1996     1995       1994       1993
                                                                              ---------------  ---------  ---------  ---------
<S>                                                                           <C>              <C>        <C>        <C>
CASH DIVIDENDS DECLARED PER COMMON SHARE
  WPLH/Interstate Energy
    Historical..............................................................     $    1.96     $    1.94  $    1.92  $    1.90
    Equivalent pro forma (1)................................................     $    1.89     $    1.89  $    1.88  $    1.87
  IES
    Historical..............................................................     $    2.10     $    2.10  $    2.10  $    2.10
    Equivalent pro forma (1)................................................     $    2.15     $    2.15  $    2.14  $    2.13
  IPC
    Historical..............................................................     $    2.08     $    2.08  $    2.08  $    2.08
    Equivalent pro forma (1)................................................     $    2.10     $    2.10  $    2.09  $    2.08
EARNINGS PER COMMON SHARE FROM CONTINUING OPERATIONS
  WPLH/Interstate Energy
    Historical (3)(6).......................................................     $    2.99     $    2.33  $    2.17  $    2.15
    Equivalent pro forma (1)(3)(6)..........................................     $    2.48     $    2.16  $    2.05  $    2.06
  IES
    Historical (3)..........................................................     $    2.27     $    2.20  $    2.34  $    2.45
    Equivalent pro forma (1)(3).............................................     $    2.83     $    2.46  $    2.34  $    2.35
  IPC
    Historical (3)..........................................................     $    2.82     $    2.63  $    1.92  $    1.73
    Equivalent pro forma (1)(3).............................................     $    2.75     $    2.40  $    2.28  $    2.29
</TABLE>
 
   
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
    
 
   
PRO FORMA DIVIDEND PAYOUT RATIO
    
 
   
    The pro forma dividend payout ratio of Interstate Energy for the twelve
months ended June 30, 1996 is based upon Interstate Energy's expected dividend
rate divided by the pro forma earnings per share for such period. It is
anticipated that Interstate Energy will retain WPLH's then current common share
dividend payment level as of the effective time of the Mergers. WPLH's current
annualized dividend rate is $1.97 per share.
    
 
   
<TABLE>
<CAPTION>
                                                                                           TWELVE MONTHS
                                                                                               ENDED
                                                                                           JUNE 30, 1996
                                                                                           -------------
<S>                                                                                        <C>
Pro Forma Dividend Payout Ratio
    Interstate Energy....................................................................        79.4%
</TABLE>
    
 
                                       18
<PAGE>
               UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION
 
    The following unaudited pro forma financial information combines the
historical consolidated balance sheets and statements of income of WPLH, IES and
IPC, including their respective Subsidiaries, after giving effect to the Mergers
and providing for the IES Ratio of 1.14 and the IPC Ratio of 1.11. The
historical data for WPLH have been adjusted to reflect the restatement of such
data to account for certain discontinued operations discussed in the notes
hereto. The unaudited pro forma combined balance sheet at June 30, 1996 gives
effect to the Mergers as if they had occurred at June 30, 1996. The unaudited
pro forma combined statements of income for each of the three years in the
period ended December 31, 1995, the six-month periods ended June 30, 1996 and
1995, and the twelve-month period ended June 30, 1996 give effect to the Mergers
as if they had occurred at January 1, 1993. These statements are prepared on the
basis of accounting for the Mergers as a pooling of interests and are based on
the assumptions set forth in the notes thereto. In addition, the pro forma
financial information does not give effect to the expected synergies or the
costs to be incurred to achieve such synergies. The pro forma financial
information, however, does reflect the transaction costs to effect the Mergers.
 
    The following pro forma financial information has been prepared from, and
should be read in conjunction with, the historical consolidated financial
statements and related notes thereto of WPLH, IES and IPC, incorporated by
reference herein. The following information is not necessarily indicative of the
financial position or operating results that would have occurred had the Mergers
been consummated on the date, or at the beginning of the periods, for which the
Mergers are being given effect nor is it necessarily indicative of future
operating results or financial position. In addition, due to the effect of
weather on sales and other factors which are characteristic of public utility
operations, financial results for the six-month periods ended June 30, 1996 and
1995 are not necessarily indicative of trends for any twelve-month period.
 
                                       19
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
                   UNAUDITED PRO FORMA COMBINED BALANCE SHEET
 
                                 JUNE 30, 1996
                                 (IN THOUSANDS)
 
ASSETS
<TABLE>
<CAPTION>
                                                                                             WPLH            IES            IPC
                                                                                         (AS REPORTED)  (AS REPORTED)  (AS REPORTED)
                                                                                         -------------  -------------  -------------
<S>                                                                                      <C>            <C>            <C>
UTILITY PLANT
  Electric.............................................................................   $ 1,686,564    $ 1,921,426     $ 843,003
  Gas..................................................................................       220,824        167,760        63,518
  Other................................................................................       166,316        109,088        --
                                                                                         -------------  -------------  -------------
      Total............................................................................     2,073,704      2,198,274       906,521
  Accumulated provision for depreciation...............................................       929,494        996,595       416,090
  Construction work in progress........................................................        52,936         82,070         6,319
  Nuclear fuel -- net..................................................................        17,247         40,532        --
                                                                                         -------------  -------------  -------------
      Net utility plant................................................................     1,214,393      1,324,281       496,750
OTHER PROPERTY, PLANT AND EQUIPMENT -- NET AND INVESTMENTS (Note 8)....................       125,270        263,990           460
CURRENT ASSETS
  Cash and cash equivalents............................................................         9,635         14,520         1,324
  Accounts receivable -- net...........................................................        81,253         38,407        27,298
  Fossil fuel inventories, at average cost.............................................        14,548         12,821        13,926
  Materials and supplies, at average cost..............................................        21,304         23,968         5,955
  Prepayments and other................................................................        39,040         45,994        12,743
                                                                                         -------------  -------------  -------------
      Total current assets.............................................................       165,780        135,710        61,246
EXTERNAL DECOMMISSIONING FUND..........................................................        84,747         52,084        --
DEFERRED CHARGES AND OTHER.............................................................       248,232        238,242        72,010
                                                                                         -------------  -------------  -------------
      TOTAL ASSETS.....................................................................   $ 1,838,422    $ 2,014,307     $ 630,466
                                                                                         -------------  -------------  -------------
                                                                                         -------------  -------------  -------------
 
<CAPTION>
                                                                                          PRO FORMA   PRO FORMA
                                                                                         ADJUSTMENTS   COMBINED
                                                                                         -----------  ----------
<S>                                                                                      <C>          <C>
UTILITY PLANT
  Electric.............................................................................   $  --       $4,450,993
  Gas..................................................................................      --          452,102
  Other................................................................................      --          275,404
                                                                                         -----------  ----------
      Total............................................................................      --        5,178,499
  Accumulated provision for depreciation...............................................      --        2,342,179
  Construction work in progress........................................................      --          141,325
  Nuclear fuel -- net..................................................................      --           57,779
                                                                                         -----------  ----------
      Net utility plant................................................................      --        3,035,424
OTHER PROPERTY, PLANT AND EQUIPMENT -- NET AND INVESTMENTS (Note 8)....................      --          389,720
CURRENT ASSETS
  Cash and cash equivalents............................................................      --           25,479
  Accounts receivable -- net...........................................................      --          146,958
  Fossil fuel inventories, at average cost.............................................      --           41,295
  Materials and supplies, at average cost..............................................      --           51,227
  Prepayments and other................................................................      --           97,777
                                                                                         -----------  ----------
      Total current assets.............................................................      --          362,736
EXTERNAL DECOMMISSIONING FUND..........................................................      --          136,831
DEFERRED CHARGES AND OTHER.............................................................      --          558,484
                                                                                         -----------  ----------
      TOTAL ASSETS.....................................................................   $  --       $4,483,195
                                                                                         -----------  ----------
                                                                                         -----------  ----------
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       20
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
             UNAUDITED PRO FORMA COMBINED BALANCE SHEET (CONTINUED)
 
                                 JUNE 30, 1996
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>
                                                                                         WPLH            IES            IPC
                                                                                     (AS REPORTED)  (AS REPORTED)  (AS REPORTED)
                                                                                     -------------  -------------  -------------
<S>                                                                                  <C>            <C>            <C>
LIABILITIES AND EQUITY
CAPITALIZATION
  Common Stock Equity:
    Common stock (Note 1)..........................................................  $         308  $     399,928   $    33,583
    Other stockholders' equity (Note 1)............................................        615,307        212,003       167,410
                                                                                     -------------  -------------  -------------
      Total common stock equity....................................................        615,615        611,931       200,993
  Preferred stock not mandatorily redeemable.......................................         59,963         18,320        10,819
  Preferred stock mandatory sinking fund...........................................       --             --              24,090
  Long-term debt -- net............................................................        423,701        604,469       171,918
                                                                                     -------------  -------------  -------------
      Total capitalization.........................................................      1,099,279      1,234,720       407,820
CURRENT LIABILITIES
  Current maturities, sinking funds, and capital lease obligations.................          3,453         37,343        17,000
  Commercial paper, notes payable and other........................................         57,534        125,000        29,700
  Variable rate demand bonds.......................................................         56,975       --             --
  Accounts payable and accruals....................................................         86,049         67,047        19,061
  Taxes accrued....................................................................         17,680         47,698        15,145
  Other accrued liabilities........................................................         50,784         69,872         8,348
                                                                                     -------------  -------------  -------------
      Total current liabilities....................................................        272,475        346,960        89,254
OTHER LIABILITIES
  Deferred income taxes............................................................        238,048        258,310        98,269
  Deferred investment tax credits..................................................         37,887         35,793        17,527
  Accrued environmental remediation costs..........................................         76,611         43,400         6,834
  Capital lease obligations........................................................       --               26,649       --
  Other liabilities and deferred credits...........................................        114,122         68,475        10,762
                                                                                     -------------  -------------  -------------
      Total other liabilities......................................................        466,668        432,627       133,392
                                                                                     -------------  -------------  -------------
    TOTAL CAPITALIZATION AND LIABILITIES...........................................  $   1,838,422  $   2,014,307   $   630,466
                                                                                     -------------  -------------  -------------
                                                                                     -------------  -------------  -------------
 
<CAPTION>
                                                                                      PRO FORMA   PRO FORMA
                                                                                     ADJUSTMENTS   COMBINED
                                                                                     -----------  ----------
<S>                                                                                  <C>          <C>
LIABILITIES AND EQUITY
CAPITALIZATION
  Common Stock Equity:
    Common stock (Note 1)..........................................................   $(433,064)  $      755
    Other stockholders' equity (Note 1)............................................     424,804    1,419,524
                                                                                     -----------  ----------
      Total common stock equity....................................................      (8,260)   1,420,279
  Preferred stock not mandatorily redeemable.......................................      --           89,102
  Preferred stock mandatory sinking fund...........................................      --           24,090
  Long-term debt -- net............................................................      --        1,200,088
                                                                                     -----------  ----------
      Total capitalization.........................................................      (8,260)   2,733,559
CURRENT LIABILITIES
  Current maturities, sinking funds, and capital lease obligations.................      --           57,796
  Commercial paper, notes payable and other........................................      --          212,234
  Variable rate demand bonds.......................................................      --           56,975
  Accounts payable and accruals....................................................      --          172,157
  Taxes accrued....................................................................      --           80,523
  Other accrued liabilities........................................................      14,000      143,004
                                                                                     -----------  ----------
      Total current liabilities....................................................      14,000      722,689
OTHER LIABILITIES
  Deferred income taxes............................................................      (5,740)     588,887
  Deferred investment tax credits..................................................      --           91,207
  Accrued environmental remediation costs..........................................      --          126,845
  Capital lease obligations........................................................      --           26,649
  Other liabilities and deferred credits...........................................      --          193,359
                                                                                     -----------  ----------
      Total other liabilities......................................................      (5,740)   1,026,947
                                                                                     -----------  ----------
    TOTAL CAPITALIZATION AND LIABILITIES...........................................   $  --       $4,483,195
                                                                                     -----------  ----------
                                                                                     -----------  ----------
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       21
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                         SIX MONTHS ENDED JUNE 30, 1996
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                               WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                           (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                           -------------  -------------  -------------  -------------  ------------
<S>                                        <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric...............................   $   285,584    $   262,400    $   132,936     $  --        $    680,920
  Gas....................................        99,743        132,651         30,411        --             262,805
  Other..................................        83,843         58,793        --             --             142,636
                                           -------------  -------------  -------------  -------------  ------------
    Total operating revenues.............       469,170        453,844        163,347        --           1,086,361
Operating Expenses
  Electric production fuels..............        55,943         43,021         28,941        --             127,905
  Purchased power........................        31,773         36,469         30,980        --              99,222
  Cost of gas sold.......................        61,054         99,250         16,585        --             176,889
  Other operation........................       151,737        104,808         25,418        --             281,963
  Maintenance............................        19,491         25,920          8,433        --              53,844
  Depreciation and amortization..........        45,828         54,608         15,175        --             115,611
  Taxes other than income taxes..........        18,055         26,004          8,638        --              52,697
                                           -------------  -------------  -------------  -------------  ------------
    Total operating expenses.............       383,881        390,080        134,170        --             908,131
                                           -------------  -------------  -------------  -------------  ------------
Operating Income.........................        85,289         63,764         29,177        --             178,230
Other Income (Expense)
  Allowance for equity funds used during
   construction..........................           905             (4)       --             --                 901
  Other income and deductions -- net.....        10,078          2,373            713        --              13,164
                                           -------------  -------------  -------------  -------------  ------------
    Total other income (expense).........        10,983          2,369            713        --              14,065
Interest Charges.........................        18,526         24,455          8,035        --              51,016
                                           -------------  -------------  -------------  -------------  ------------
Income from continuing operations before
 income taxes and preferred dividends....        77,746         41,678         21,855        --             141,279
Income Taxes.............................        27,871         19,070          8,387        --              55,328
Preferred dividends of subsidiaries (Note
 2)......................................         1,656            457          1,231        --               3,344
                                           -------------  -------------  -------------  -------------  ------------
Income from Continuing Operations (Notes
 3 and 6)................................   $    48,219    $    22,151    $    12,237     $  --        $     82,607
                                           -------------  -------------  -------------  -------------  ------------
                                           -------------  -------------  -------------  -------------  ------------
Average Common Shares Outstanding (Note
 1)......................................        30,784         29,723          9,566         5,213          75,286
Earnings per share of Common Stock from
 continuing operations...................      $1.57          $0.75         $1.28           $ --          $1.10
                                              -----          -----          -----          -----           ----
                                              -----          -----          -----          -----           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       22
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                         SIX MONTHS ENDED JUNE 30, 1995
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                                WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                            (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS    COMBINED
                                            -------------  -------------  -------------  -------------  -----------
<S>                                         <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric................................   $   257,244    $   249,626    $   128,887     $  --         $ 635,757
  Gas.....................................        77,657         96,992         25,932        --           200,581
  Other...................................        56,963         49,221        --             --           106,184
                                            -------------  -------------  -------------  -------------  -----------
    Total operating revenues..............       391,864        395,839        154,819        --           942,522
Operating Expenses
  Electric production fuels...............        57,611         39,746         32,618        --           129,975
  Purchased power.........................        17,382         33,444         27,163        --            77,989
  Cost of gas sold........................        46,241         72,356         13,831        --           132,428
  Other operation.........................       119,947         93,965         18,974        --           232,886
  Maintenance.............................        23,048         23,489          7,242        --            53,779
  Depreciation and amortization...........        42,836         50,461         14,487        --           107,784
  Taxes other than income taxes...........        18,671         26,807          8,745        --            54,223
                                            -------------  -------------  -------------  -------------  -----------
    Total operating expenses..............       325,736        340,268        123,060        --           789,064
                                            -------------  -------------  -------------  -------------  -----------
Operating Income..........................        66,128         55,571         31,759        --           153,458
Other Income (Expense)
  Allowance for equity funds used during
   construction...........................           722            360        --             --             1,082
  Other income and deductions -- net......          (106)           523         (4,561)       --            (4,144)
                                            -------------  -------------  -------------  -------------  -----------
    Total other income (expense)..........           616            883         (4,561)       --            (3,062)
Interest Charges..........................        20,217         23,507          8,396        --            52,120
                                            -------------  -------------  -------------  -------------  -----------
Income from continuing operations before
 income taxes and preferred dividends.....        46,527         32,947         18,802        --            98,276
Income Taxes..............................        16,971         13,242          7,180        --            37,393
Preferred dividends of subsidiaries (Note
 2).......................................         1,655            457          1,228        --             3,340
                                            -------------  -------------  -------------  -------------  -----------
Income from Continuing Operations (Notes 3
 and 6)...................................   $    27,901    $    19,248    $    10,394     $  --         $  57,543
                                            -------------  -------------  -------------  -------------  -----------
                                            -------------  -------------  -------------  -------------  -----------
Average Common Shares Outstanding (Note
 1).......................................        30,774         29,008          9,564         5,113        74,459
Earnings per share of Common Stock from
 continuing operations....................      $0.91          $0.66         $1.08           $ --         $0.77
                                               -----          -----          -----          -----         -----
                                               -----          -----          -----          -----         -----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       23
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                       TWELVE MONTHS ENDED JUNE 30, 1996
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                               WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                           (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                           -------------  -------------  -------------  -------------  ------------
<S>                                        <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric...............................   $   574,664    $   573,246    $   278,922     $  --        $  1,426,832
  Gas....................................       161,251        225,999         48,148        --             435,398
  Other..................................       148,646        109,773        --             --             258,419
                                           -------------  -------------  -------------  -------------  ------------
    Total operating revenues.............       884,561        909,018        327,070        --           2,120,649
Operating Expenses.......................
  Electric production fuels..............       114,820         99,530         58,487        --             272,837
  Purchased power........................        58,406         69,899         61,382        --             189,687
  Cost of gas sold.......................        98,815        168,610         28,642        --             296,067
  Other operation........................       282,586        212,231         52,161        --             546,978
  Maintenance............................        38,486         48,525         16,072        --             103,083
  Depreciation and amortization..........        89,311        102,104         30,249        --             221,664
  Taxes other than income taxes..........        33,572         48,211         15,882        --              97,665
                                           -------------  -------------  -------------  -------------  ------------
    Total operating expenses.............       715,996        749,110        262,875        --           1,727,981
Operating Income.........................       168,565        159,908         64,195        --             392,668
                                           -------------  -------------  -------------  -------------  ------------
Other Income (Expense)...................
  Allowance for equity funds used during
   construction..........................         2,484             22              3        --               2,509
  Other income and deductions -- net.....        13,287          5,016          2,885        --              21,188
                                           -------------  -------------  -------------  -------------  ------------
    Total other income (expense).........        15,771          5,038          2,888        --              23,697
Interest Charges.........................        42,081         48,636         16,434        --             107,151
                                           -------------  -------------  -------------  -------------  ------------
Income from continuing operations before
 income taxes and preferred dividends....       142,255        116,310         50,649        --             309,214
Income Taxes.............................        47,008         48,318         21,146        --             116,472
Preferred dividends of subsidiaries (Note
 2)......................................         3,311            914          2,461        --               6,686
                                           -------------  -------------  -------------  -------------  ------------
Income from Continuing Operations (Notes
 3 and 6)................................   $    91,936    $    67,078    $    27,042     $  --        $    186,056
                                           -------------  -------------  -------------  -------------  ------------
                                           -------------  -------------  -------------  -------------  ------------
Average Common Shares Outstanding (Note
 1)......................................        30,779         29,560          9,565         5,190          75,094
Earnings per share of Common Stock from
 continuing operations...................      $2.99          $2.27         $2.82           $ --          $2.48
                                              -----          -----          -----          -----           ----
                                              -----          -----          -----          -----           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       24
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                          YEAR ENDED DECEMBER 31, 1995
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                             WPLH            IES            IPC         PRO FORMA      PRO FORMA
                                         (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                         -------------  -------------  -------------  -------------  -------------
<S>                                      <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric.............................   $   546,324    $   560,471    $   274,873     $  --        $   1,381,668
  Gas..................................       139,165        190,339         43,669        --              373,173
  Other................................       121,766        100,200        --             --              221,966
                                         -------------  -------------  -------------        -----    -------------
    Total operating revenues...........       807,255        851,010        318,542        --            1,976,807
Operating Expenses
  Electric production fuels............       116,488         96,256         62,164        --              274,908
  Purchased power......................        44,015         66,874         57,566        --              168,455
  Cost of gas sold.....................        84,002        141,716         25,888        --              251,606
  Other operation......................       250,796        201,390         45,717        --              497,903
  Maintenance..........................        42,043         46,093         14,881        --              103,017
  Depreciation and amortization........        86,319         97,958         29,560        --              213,837
  Taxes other than income
   taxes...............................        34,188         49,011         15,990        --               99,189
                                         -------------  -------------  -------------        -----    -------------
    Total operating expenses...........       657,851        699,298        251,766        --            1,608,915
                                         -------------  -------------  -------------        -----    -------------
Operating Income.......................       149,404        151,712         66,776        --              367,892
Other Income (Expense)
  Allowance for equity funds used
   during construction.................         1,425            386        --             --                1,811
  Other income and deductions -- net...         3,103          3,170         (2,872)       --                3,401
                                         -------------  -------------  -------------        -----    -------------
    Total other income
     (expense).........................         4,528          3,556         (2,872)       --                5,212
Interest Charges.......................        42,896         47,689         16,795        --              107,380
                                         -------------  -------------  -------------        -----    -------------
Income from continuing operations
 before income taxes and preferred
 dividends.............................       111,036        107,579         47,109        --              265,724
Income Taxes...........................        36,108         42,489         19,453        --               98,050
Preferred dividends of subsidiaries
 (Note 2)..............................         3,310            914          2,458        --                6,682
                                         -------------  -------------  -------------        -----    -------------
Income from Continuing Operations
 (Notes 3 and 6).......................   $    71,618    $    64,176    $    25,198     $  --        $     160,992
                                         -------------  -------------  -------------        -----    -------------
                                         -------------  -------------  -------------        -----    -------------
Average Common Shares Outstanding (Note
 1)....................................        30,774         29,202          9,564         5,140           74,680
Earnings per share of Common Stock from
 continuing operations.................      $2.33          $2.20         $2.63       $    --            $2.16
                                            -----          -----          -----          -----           ----
                                            -----          -----          -----          -----           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       25
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
 
                          YEAR ENDED DECEMBER 31, 1994
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                             WPLH            IES            IPC         PRO FORMA      PRO FORMA
                                         (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                         -------------  -------------  -------------  -------------  -------------
<S>                                      <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric.............................   $   531,747    $   537,327    $   261,730     $  --        $   1,330,804
  Gas..................................       151,931        165,569         45,920        --              363,420
  Other................................       112,039         82,968        --             --              195,007
                                         -------------  -------------  -------------        -----    -------------
    Total operating revenues...........       795,717        785,864        307,650        --            1,889,231
Operating Expenses
  Electric production fuels............       123,469         85,952         61,384        --              270,805
  Purchased power......................        37,913         68,794         58,339        --              165,046
  Cost of gas sold.....................       100,942        120,795         30,905        --              252,642
  Other operation......................       246,212        176,863         51,917        --              474,992
  Maintenance..........................        41,227         52,841         17,160        --              111,228
  Depreciation and amortization........        80,351         86,378         28,212        --              194,941
  Taxes other than income
   taxes...............................        33,788         46,308         16,298        --               96,394
                                         -------------  -------------  -------------        -----    -------------
    Total operating expenses...........       663,902        637,931        264,215        --            1,566,048
                                         -------------  -------------  -------------        -----    -------------
Operating Income.......................       131,815        147,933         43,435        --              323,183
Other Income (Expense)
  Allowance for equity funds used
   during construction.................         3,009          2,299            166        --                5,474
  Other income and deductions -- net...         7,610          3,472          3,100        --               14,182
                                         -------------  -------------  -------------        -----    -------------
    Total other income
     (expense).........................        10,619          5,771          3,266        --               19,656
Interest Charges.......................        36,657         44,399         16,845        --               97,901
                                         -------------  -------------  -------------        -----    -------------
Income from continuing operations
 before income taxes and preferred
 dividends.............................       105,777        109,305         29,856        --              244,938
Income Taxes...........................        36,043         41,573          9,189        --               86,805
Preferred dividends of subsidiaries
 (Note 2)..............................         3,310            914          2,454        --                6,678
                                         -------------  -------------  -------------        -----    -------------
Income from Continuing Operations
 (Notes 3 and 6).......................   $    66,424    $    66,818    $    18,213     $  --        $     151,455
                                         -------------  -------------  -------------        -----    -------------
                                         -------------  -------------  -------------        -----    -------------
Average Common Shares Outstanding (Note
 1)....................................        30,671         28,560          9,479         5,041           73,751
Earnings per share of Common Stock from
 continuing operations.................      $2.17          $2.34         $1.92       $    --            $2.05
                                            -----          -----          -----          -----           ----
                                            -----          -----          -----          -----           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       26
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
 
                          YEAR ENDED DECEMBER 31, 1993
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                             WPLH            IES            IPC         PRO FORMA      PRO FORMA
                                         (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                         -------------  -------------  -------------  -------------  -------------
<S>                                      <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric.............................   $   503,187    $   550,521    $   255,759     $  --        $   1,309,467
  Gas..................................       137,270        181,923         53,709        --              372,902
  Other................................        98,147         68,822        --             --              166,969
                                         -------------  -------------  -------------        -----    -------------
    Total operating revenues...........       738,604        801,266        309,468        --            1,849,338
Operating Expenses
  Electric production fuels............       123,919         87,702         64,059        --              275,680
  Purchased power......................        28,574         93,449         53,936        --              175,959
  Cost of gas sold.....................        90,505        135,830         38,309        --              264,644
  Other operation......................       221,840        162,642         48,567        --              433,049
  Maintenance..........................        44,763         48,913         16,771        --              110,447
  Depreciation and amortization........        68,680         77,012         26,955        --              172,647
  Taxes other than income taxes........        32,379         44,449         17,080        --               93,908
                                         -------------  -------------  -------------        -----    -------------
    Total operating expenses...........       610,660        649,997        265,677        --            1,526,334
                                         -------------  -------------  -------------        -----    -------------
Operating Income.......................       127,944        151,269         43,791        --              323,004
Other Income (Expense)
  Allowance for equity funds used
   during construction.................         2,978            824             68        --                3,870
  Other income and deductions net......          (633)        (2,908)         1,209        --               (2,332)
                                         -------------  -------------  -------------        -----    -------------
    Total other income (expense).......         2,345         (2,084)         1,277        --                1,538
Interest Charges.......................        37,020         43,292         16,617        --               96,929
                                         -------------  -------------  -------------        -----    -------------
Income from continuing operations
 before income taxes and preferred
 dividends.............................        93,269        105,893         28,451        --              227,613
Income Taxes...........................        25,656         37,041          9,464        --               72,161
Preferred dividends of subsidiaries
 (Note 2)..............................         3,928            914          2,861        --                7,703
                                         -------------  -------------  -------------        -----    -------------
Income from Continuing Operations
 (Notes 3 and 6).......................   $    63,685    $    67,938    $    16,126     $  --        $     147,749
                                         -------------  -------------  -------------        -----    -------------
                                         -------------  -------------  -------------        -----    -------------
Average Common Shares Outstanding (Note
 1)....................................        29,681         27,764          9,316         4,912           71,673
Earnings per share of Common Stock from
 continuing operations.................      $2.15          $2.45         $1.73       $    --            $2.06
                                            -----          -----          -----          -----           ----
                                            -----          -----          -----          -----           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                       27
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                         COMBINED FINANCIAL STATEMENTS
 
1.  The pro forma combined financial statements reflect the conversion of each
    share of IES Common Stock (no par value) outstanding into 1.14 shares of
    WPLH Common Stock ($.01 par value) and the conversion of each share of IPC
    Common Stock ($3.50 par value) into 1.11 of a share of WPLH Common Stock
    ($.01 par value), and the continuation of each share of WPLH Common Stock
    ($.01 par value) outstanding as one share of Interstate Energy Common Stock,
    as provided in the Merger Agreement. The pro forma adjustment to common
    stock equity restates the common stock account to equal par value for all
    shares to be issued ($.01 par value per share of Interstate Energy Common
    Stock) and reclassifies the excess to other stockholders' equity. The pro
    forma combined statements of income are presented as if the companies were
    combined on January 1, 1993. The pro forma combined balance sheet gives
    effect to the Mergers as if they occurred at June 30, 1996.
 
    The number of shares of common stock used for calculating per share amounts
    is based on the exchange ratios shown below.
 
        AVERAGE NUMBER OF SHARES OUTSTANDING FOR THE TWELVE MONTHS ENDED
 
<TABLE>
<CAPTION>
                   EXCHANGE       AS REPORTED   PRO FORMA   AS REPORTED   PRO FORMA   AS REPORTED   PRO FORMA
                     RATIO          6/30/96      6/30/96     12/31/95     12/31/95     12/31/94     12/31/94
               -----------------  -----------  -----------  -----------  -----------  -----------  -----------
                                                                 (IN THOUSANDS)
<S>            <C>                <C>          <C>          <C>          <C>          <C>          <C>
IES..........           1.14          29,560       33,698       29,202       33,290       28,560       32,558
IPC..........           1.11           9,565       10,617        9,564       10,616        9,479       10,522
WPLH.........            N/A          30,779       30,779       30,774       30,774       30,671       30,671
</TABLE>
 
<TABLE>
<CAPTION>
                                         EXCHANGE       AS REPORTED   PRO FORMA
                                           RATIO         12/31/93     12/31/93
                                     -----------------  -----------  -----------
                                                             (IN THOUSANDS)
<S>                                  <C>                <C>          <C>          <C>          <C>
IES................................           1.14          27,764       31,651
IPC................................           1.11           9,316       10,341
WPLH...............................            N/A          29,681       29,681
</TABLE>
 
         AVERAGE NUMBER OF SHARES OUTSTANDING FOR THE SIX MONTHS ENDED
 
<TABLE>
<CAPTION>
                                         EXCHANGE       AS REPORTED   PRO FORMA   AS REPORTED   PRO FORMA
                                           RATIO          6/30/96      6/30/96      6/30/95      6/30/95
                                     -----------------  -----------  -----------  -----------  -----------
                                                                          (IN THOUSANDS)
<S>                                  <C>                <C>          <C>          <C>          <C>
IES................................           1.14          29,723       33,884       29,008       33,069
IPC................................           1.11           9,566       10,618        9,564       10,616
WPLH...............................            N/A          30,784       30,784       30,774       30,774
</TABLE>
 
2.  The IPC Preferred Stock has been reclassified in the pro forma statements as
    preferred stock of subsidiary companies and deducted in the determination of
    income from continuing operations which reflects the holding company
    structure of the entity formed through the Mergers.
 
3.  Nonrecurring items affecting WPLH's 1994 performance included the impact of
    early retirement and severance programs and the reversal of a coal contract
    penalty assessed by the Wisconsin Commission which was charged to income in
    1989. The net after-tax impact of these items on income from continuing
    operations for the year ended December 31, 1994 was a decrease of $8.3
    million related to the early retirement and severance programs offset by an
    increase of $4.9 million related to the coal contract penalty reversal.
    Nonrecurring items affecting WPLH's
 
                                       28
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                   COMBINED FINANCIAL STATEMENTS (CONTINUED)
    performance for the twelve months ended June 30, 1996 included a net
    after-tax gain of $2.0 million on the sale of an HDC real estate investment,
    Heartland Retirement Services, and a net after-tax gain of $3.4 million on
    the sale of a combustion turbine.
 
    IPC's income from continuing operations includes expenses associated with
    the environmental investigation and remediation costs of former manufactured
    gas plants. Operating expenses for the twelve months ended June 30, 1996 and
    for the years ended December 31, 1995, 1994 and 1993 include $0.1 million,
    $0.3 million, $0.8 million and $3.5 million, respectively, for these costs.
    Other operating expenses for the twelve months ended June 30, 1996 and for
    the year ended December 31, 1995 also include $1.2 million and $0.7 million,
    respectively, of legal fees related to coal tar remediation, compared with
    $1.0 million and $0.3 million for the years ended December 31, 1994 and
    1993, respectively. For the twelve months ended June 30, 1996 and for the
    years ended December 31, 1995, 1994 and 1993, $0.2 million, $0.6 million,
    $0.7 million and $0.6 million, respectively, of the foregoing expenses were
    recovered in rates.
 
    Nonrecurring items affecting IES's income from continuing operations for the
    year ended December 31, 1993 include various gains and losses related to
    sales of assets and property valuation adjustments associated with its
    nonregulated businesses. The net after-tax impact of these items on income
    from continuing operations for the year ended December 31, 1993 was a
    decrease of $2.0 million.
 
4.  The allocation between WPLH, IES and IPC and their customers of the
    estimated costs savings of approximately $749 million over ten years
    resulting from the Mergers, net of the costs incurred to achieve such
    savings, will be subject to regulatory review and approval. Costs arising
    from the proposed Mergers are currently estimated to be approximately $78.4
    million (including transaction costs of $11.5 million related to fees for
    financial advisors and $2.5 million related to fees for attorneys,
    accountants, consultants, filings and printing). Such costs do not reflect
    the increased costs associated with the MEC Takeover Proposal and the
    increase in the IES Ratio, which WPLH, IES and IPC are unable to estimate as
    of the date of this Supplement to Joint Proxy Statement/Prospectus, but
    which the parties believe will exceed $4 million. In addition, none of the
    estimated cost savings, or the costs to achieve such savings, have been
    reflected in the pro forma combined financial statements. The transaction
    costs have been reflected in the pro forma balance sheet at June 30, 1996
    such that shareowner equity has been reduced by $8.26 million, accrued
    liabilities have been increased by $14.0 million, and deferred taxes were
    decreased by $5.74 million.
 
5.  Intercompany transactions (including purchased and exchange power
    transactions) between WPLH, IES and IPC during the periods presented were
    included in the determination of regulated rates and were not material.
    Accordingly, no pro forma adjustments were made to eliminate such
    transactions.
 
6.  The financial statements of WPLH reflect the discontinuance of operations of
    its utility energy and marketing consulting business in 1995. The
    discontinuance of this business resulted in a pre-tax loss of $7.7 million
    ($11.0 million net of the applicable income tax expenses) in 1995. Operating
    revenues, operating expenses, other income and expense and income taxes for
    the discontinued operations for the time periods presented have been
    excluded from income from continuing operations. Interest expense has been
    adjusted for the amounts associated with direct obligations of the
    discontinued operations.
 
                                       29
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                   COMBINED FINANCIAL STATEMENTS (CONTINUED)
 
    Operating revenues, related losses, and income tax benefits associated with
    the discontinued operations for the indicated time periods were as follows:
 
<TABLE>
<CAPTION>
                                                       TWELVE MONTHS
                                                           ENDED           YEAR ENDED DECEMBER 31,
                                                          JUNE 30,     -------------------------------
                                                            1996         1995       1994       1993
                                                       --------------  ---------  ---------  ---------
                                                                   (DOLLARS IN THOUSANDS)
<S>                                                    <C>             <C>        <C>        <C>
Operating revenues...................................    $    8,806    $  24,979  $  34,798  $  33,340
                                                       --------------  ---------  ---------  ---------
                                                       --------------  ---------  ---------  ---------
Loss from discontinued operations before tax
 benefit.............................................    $    1,496    $   3,663  $   1,806  $   1,761
Income tax benefit...................................           593        1,451        632        599
                                                       --------------  ---------  ---------  ---------
Loss from discontinued operations....................    $      903    $   2,212  $   1,174  $   1,162
                                                       --------------  ---------  ---------  ---------
                                                       --------------  ---------  ---------  ---------
</TABLE>
 
7.  Accounting principles have been consistently applied in the financial
    statement presentations for WPLH, IES and IPC with one exception. IPC does
    not include unbilled electric and gas revenues in its calculation of total
    revenues. The utility subsidiaries of WPLH and IES accrue unbilled revenues.
    The impact of this difference in accounting principles among the companies
    does not have a material impact on the unaudited pro forma combined
    financial statements as presented and, accordingly, no adjustments have been
    made to conform accounting principles.
 
8.  At June 30, 1996, IES had a $10.0 million investment in Class A common stock
    of McLeod, Inc., a $9.2 million investment in Class B common stock and
    vested options that, if exercised, would represent an additional investment
    of approximately $2.3 million. McLeod provides local and long-distance
    telecommunications services to business customers and other services related
    to fiber optics.
 
    In June 1996, McLeod completed an initial public offering (IPO) of its Class
    A common stock. As of June 30, 1996, IES is the beneficial owner of
    approximately 10.2 million total shares on a fully diluted basis. Class B
    shares are convertible at the option of IES into Class A shares at any time
    on a one-for-one basis. The rights of McLeod Class A common stock and Class
    B common stock are substantially identical except that Class A common stock
    has 1 vote per share and Class B common stock has 0.40 votes per share. IES
    currently accounts for this investment under the cost method.
 
    IES has entered into an agreement with McLeod which provides that for two
    years commencing on June 10, 1996, IES cannot sell or otherwise dispose of
    any of its securities of McLeod without the consent of the McLeod Board of
    Directors. Also, under certain SEC rules, IES may be subject to certain
    restrictions with respect to the sale of McLeod shares for a period of time.
    These contractual and SEC sale restrictions result in restricted stock under
    the provisions of Statement of Financial Accounting Standards No. 115 (SFAS
    No. 115), Accounting for Certain Investments in Debt and Equity Securities,
    until such time as the restrictions lapse and such shares became qualified
    for sale within a one year period. As a result, IES currently carries this
    investment at cost.
 
    Under the provisions of SFAS No. 115, the carrying value of the McLeod
    investment will be adjusted to estimated fair value at the time such shares
    are not considered to be restricted stock. Under the SEC rules, it is
    possible that the shares will become unrestricted over time rather than all
    at once. Therefore, adjustments to market value under the provisions of SFAS
    No. 115 would only be recorded for the portion of shares held that are no
    longer deemed to be restricted. Any
 
                                       30
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                   COMBINED FINANCIAL STATEMENTS (CONTINUED)
    such adjustments to reflect the estimated fair value of this investment
    would be reflected as an increase in the investment carrying value with the
    unrealized gains reported as a net of tax amount in other common
    shareholders equity until realized (I.E., sold by IES).
 
    The closing price of the McLeod Class A common stock on June 30, 1996, on
    the Nasdaq National Market, was $24.00 per share. The current market value
    of the shares IES beneficially owns (approximately 10.2 million shares) is
    currently impacted by, among other things, the fact that the shares cannot
    be sold for a period of time and it is not possible to estimate what the
    market value of the shares will be at the point in time such sale
    restrictions are lifted. In addition, any gain upon an eventual sale of this
    investment would likely be subject to tax.
 
                                       31
<PAGE>
                    INCORPORATION OF DOCUMENTS BY REFERENCE
 
    THIS SUPPLEMENT TO JOINT PROXY STATEMENT/PROSPECTUS INCORPORATES DOCUMENTS
BY REFERENCE WHICH ARE NOT PRESENTED HEREIN OR DELIVERED HEREWITH. SUCH
DOCUMENTS (OTHER THAN EXHIBITS TO SUCH DOCUMENTS UNLESS SUCH EXHIBITS ARE
SPECIFICALLY INCORPORATED BY REFERENCE) ARE AVAILABLE TO ANY PERSON, INCLUDING
ANY BENEFICIAL OWNER, TO WHOM THIS SUPPLEMENT TO JOINT PROXY
STATEMENT/PROSPECTUS IS DELIVERED, UPON WRITTEN OR ORAL REQUEST, WITHOUT CHARGE,
IN THE CASE OF DOCUMENTS RELATING TO WPLH, DIRECTED TO EDWARD M. GLEASON, VICE
PRESIDENT, TREASURER AND CORPORATE SECRETARY, WPL HOLDINGS, INC., 222 WEST
WASHINGTON AVENUE, P.O. BOX 2568, MADISON, WISCONSIN 53701-2568 (TELEPHONE
NUMBER (608) 252-3311), IN THE CASE OF DOCUMENTS RELATING TO IES, DIRECTED TO
STEPHEN W. SOUTHWICK, ESQ., VICE PRESIDENT, GENERAL COUNSEL & SECRETARY, IES
INDUSTRIES INC., IES TOWER, 200 FIRST STREET S.E., CEDAR RAPIDS, IOWA 52401
(TELEPHONE NUMBER (319) 398-4411), OR IN THE CASE OF DOCUMENTS RELATING TO IPC,
DIRECTED TO JOSEPH C. MCGOWAN, SECRETARY AND TREASURER, INTERSTATE POWER
COMPANY, 1000 MAIN STREET, P.O. BOX 769, DUBUQUE, IOWA 52004-0769 (TELEPHONE
NUMBER (319) 582-5421). IN ORDER TO ENSURE TIMELY DELIVERY OF THE DOCUMENTS, ANY
REQUESTS SHOULD BE MADE BY AUGUST 28, 1996.
 
    An additional copy of the Original Joint Proxy Statement/Prospectus may be
obtained by any WPLH, IES or IPC shareowner by calling, in the case of WPLH
shareowners, WPLH Shareowner Services at (608) 252-3110 (local) or (800)
356-5343 (toll-free), in the case of IES shareholders, IES Shareholder Services
at (319) 398-7755 (local) or (800) 247-9785 (toll-free) or, in the case of IPC
stockholders, IPC Stockholder Services (collect) at (319) 582-5421, ext. 465.
 
    The following documents filed with the SEC by WPLH (File No. 1-9894), IES
(File No. 1-9187) or IPC (File No. 1-3632) pursuant to the Exchange Act are
incorporated in this Supplement to Joint Proxy Statement/Prospectus by
reference:
 
   
        1.  WPLH's Annual Report on Form 10-K filed on March 29, 1996 for the
    year ended December 31, 1995, as amended by the Form 10-K/A filed on April
    29, 1996.
    
 
   
        2.  WPLH's Quarterly Reports on Form 10-Q for the quarters ended March
    31 and June 30, 1996, filed on May 15 and August 14, 1996, respectively, as
    amended by the Form 10-Q/A filed August 16, 1996.
    
 
   
        3.  WPLH's Current Reports on Form 8-K dated January 17 and May 22,
    1996, filed on January 17 and May 24, 1996, respectively.
    
 
   
        4.  IES's Annual Report on Form 10-K filed on March 7, 1996 for the year
    ended December 31, 1995, as amended by the Form 10-K/A filed on April 29,
    1996.
    
 
   
        5.  IES's Quarterly Reports on Form 10-Q for the quarters ended March 31
    and June 30, 1996, filed on May 14 and August 14, 1996, respectively.
    
 
   
        6.  IES's Current Reports on Form 8-K dated February 9, April 3, April
    12 and May 22, 1996, filed on February 20, April 8, April 18 and May 24,
    1996, respectively.
    
 
   
        7.  The description of IES Common Stock in IE Industries Inc.'s
    Registration Statement on Form 8-B filed June 20, 1986, as amended, and the
    share purchase rights associated with IES Common Stock contained in IES's
    registration statement on Form 8-A filed November 13, 1991, as amended.
    
 
   
        8.  IPC's Annual Report on Form 10-K filed on March 29, 1996 for the
    year ended December 31, 1995, as amended by the Form 10-K/A filed on April
    29, 1996.
    
 
   
        9.  IPC's Quarterly Reports on Form 10-Q for the quarters ended March 31
    and June 30, 1996, filed on May 15 and August 13, 1996, respectively, as
    amended by the Form 10-Q/A filed on August 14, 1996.
    
 
   
        10. IPC's Current Report on Form 8-K dated May 22, 1996, filed on May
    29, 1996.
    
 
                                       32
<PAGE>
   
        11. The description of IPC Common Stock contained in IPC's registration
    statements filed pursuant to Section 12 of the Exchange Act and any
    amendment or report filed for the purpose of updating such description.
    
 
    In lieu of incorporating by reference the description of WPLH Common Stock
(including the accompanying common stock purchase rights) contained in WPLH's
Form 8-B and Form 8-A registration statements filed pursuant to Section 12 of
the Exchange Act, such description is included in the Original Joint Proxy
Statement/Prospectus. See "Description of Interstate Energy Capital Stock."
 
    The information relating to WPLH, IES and IPC contained in the Original
Joint Proxy Statement/Prospectus, as supplemented hereby, does not purport to be
comprehensive and should be read together with the information in the documents
incorporated by reference herein.
 
    All documents filed by WPLH, IES or IPC pursuant to Sections 13(a), 13(c),
14 or 15(d) of the Exchange Act subsequent to the date hereof and prior to the
date of the WPLH Meeting on Thursday, September 5, 1996, and any adjournment or
postponement thereof, the IES Meeting on Thursday, September 5, 1996, and any
adjournment or postponement thereof, or the IPC Meeting on Thursday, September
5, 1996, and any adjournment or postponement thereof, respectively, shall be
deemed to be incorporated by reference herein and into the Original Joint Proxy
Statement/Prospectus, as supplemented hereby, and to be a part hereof and
thereof from the date of filing of such documents.
 
    Any statement contained in a document incorporated by reference herein or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Supplement to Joint Proxy Statement/Prospectus
to the extent that a statement contained herein or in any other subsequently
filed document which also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any statement so modified or superseded
shall not be deemed, except as so modified or superseded, to constitute a part
of this Supplement to Joint Proxy Statement/Prospectus.
 
    The Original Joint Proxy Statement/Prospectus as supplemented constitutes a
prospectus of WPLH (to be renamed Interstate Energy) with respect to up to
46,879,250 shares of Interstate Energy Common Stock to be issued pursuant to or
as contemplated by the Merger Agreement. The Original Joint Proxy
Statement/Prospectus as supplemented also constitutes a prospectus of New IPC
with respect to up to 761,381 shares of New IPC Preferred Stock to be issued,
assuming that the IPC Reincorporation Merger is effected, pursuant to or as
contemplated by the Merger Agreement.
 
                                       33
<PAGE>
                                                                         ANNEX I
 
                                AMENDMENT NO. 2
                                       TO
                          AGREEMENT AND PLAN OF MERGER
 
    THIS AMENDMENT No. 2 (this "Amendment No. 2") dated as of August 16, 1996,
by and among WPL Holdings, Inc., a holding company incorporated under the laws
of the State of Wisconsin ("WPL"), IES Industries Inc., a holding company
incorporated under the laws of the State of Iowa ("IES"), Interstate Power
Company, an operating public utility incorporated under the laws of the State of
Delaware ("Interstate"), WPLH Acquisition Co., a wholly-owned subsidiary of WPL
incorporated under the laws of the State of Wisconsin ("Acquisition"), and
Interstate Power Company, a wholly-owned subsidiary of Interstate incorporated
under the laws of the State of Wisconsin ("New Interstate");
 
                              W I T N E S S E T H:
 
    WHEREAS, the parties hereto have entered into an Agreement and Plan of
Merger dated as of November 10, 1995, as amended (the "Merger Agreement");
 
    WHEREAS, in furtherance of the transactions contemplated therein, the
respective parties have agreed to make certain further amendments to the Merger
Agreement;
 
    NOW, THEREFORE, in consideration of the premises and the representations,
warranties, covenants and agreements contained herein, the parties hereto,
intending to be legally bound hereby, agree as follows:
 
    1.  AMENDMENTS.  Upon the execution of this Amendment No. 2 by all parties
hereto, the Merger Agreement shall be amended as follows:
 
        (a) Section 2.1(b)(i) of the Merger Agreement shall be amended by
    deleting such section in its entirety and replacing it with the following
    language:
 
               "Each issued and outstanding share of IES Common Stock
           (other than shares canceled pursuant to Section 2.1(a)(i)
           and IES Dissenting Shares (as hereinafter defined)) shall
           be converted into the right to receive 1.14 (the "IES
           Ratio") duly authorized, validly issued, fully paid and
           nonassessable (except as otherwise provided in Section
           180.0622(2)(b) of the WBCL) shares of Common Stock, par
           value $.01 per share, of WPL ("WPL Common Stock"),
           including, if applicable, associated rights (the "WPL
           Rights") to purchase shares of WPL Common Stock pursuant
           to the terms of that certain Rights Agreement between WPL
           and Morgan Shareholder Services Trust Company, as Rights
           Agent thereunder, dated as of February 22, 1989 (the "WPL
           Rights Agreement"). Until the Distribution Date (as
           defined in the WPL Rights Agreement) all references in
           this Agreement to the WPL Common Stock shall be deemed to
           include the associated WPL Rights."
 
        (b) The Index of Defined Terms which precedes the body of the Merger
    Agreement shall be amended to delete the defined terms "McLeod Contingency"
    and "McLeod."
 
    2.  REFERENCES TO MERGER AGREEMENT.  From and after the date of this
Amendment No. 2, each reference in the Merger Agreement to "this Agreement,"
"hereof," "hereunder" or words of like import, and all references to the Merger
Agreement in any and all agreements, instruments, documents, notes, certificates
and other writings of every kind and nature, shall be deemed to mean the Merger
Agreement as modified and amended by this Amendment No. 2.
 
    3.  FULL FORCE AND EFFECT.  The Merger Agreement, as amended by this
Amendment No. 2, is and shall remain in full force and effect and is hereby in
all respects ratified and confirmed.
 
                                      I-1
<PAGE>
    4.  COUNTERPARTS.  This Amendment No. 2 may be executed in counterparts,
each of which shall be deemed to be an original, with the same effect as if the
signatures thereto and hereto were upon the same instrument.
 
    IN WITNESS WHEREOF, WPL, IES, Interstate, Acquisition and New Interstate
have caused this Amendment No. 2 to be signed by their respective officers
thereunto duly authorized as of the date first written above.
 
<TABLE>
<S>                                            <C>
                                               WPL HOLDINGS, INC.
Attest:
 
                                               By: /s/ERROLL B. DAVIS, JR.
          By: /s/EDWARD M. GLEASON                 Name: Erroll B. Davis, Jr
              Edward M. Gleason                    Title:  PRESIDENT AND CHIEF EXECUTIVE
             CORPORATE SECRETARY                         OFFICER
 
                                               IES INDUSTRIES INC.
 
Attest:
 
                                               By: /s/LEE LIU
         By: /s/STEPHEN W. SOUTHWICK               Name: Lee Liu
            Stephen W. Southwick                   Title:  CHAIRMAN OF THE BOARD, PRESIDENT
        SECRETARY AND GENERAL COUNSEL                    AND CHIEF EXECUTIVE OFFICER
 
                                               INTERSTATE POWER COMPANY
                                               (a Delaware corporation)
 
Attest:
 
          By: /s/JOSEPH C. MCGOWAN             By: /s/MICHAEL R. CHASE
              Joseph C. McGowan                    Name: Michael R. Chase
           SECRETARY AND TREASURER                 Title:  EXECUTIVE VICE PRESIDENT
 
                                               WPLH ACQUISITION CO.
 
Attest:
 
          By: /s/EDWARD M. GLEASON             By: /s/ERROLL B. DAVIS, JR.
              Edward M. Gleason                    Name: Erroll B. Davis, Jr.
                  SECRETARY                        Title:  PRESIDENT
 
                                               INTERSTATE POWER COMPANY
                                               (a Wisconsin corporation)
 
Attest:
 
          By: /s/JOSEPH C. MCGOWAN             By: /s/MICHAEL R. CHASE
              Joseph C. McGowan                    Name: Michael R. Chase
                  SECRETARY                        Title:  PRESIDENT
</TABLE>
 
                                      I-2
<PAGE>
                                                                        ANNEX II
 
Merrill Lynch
 
   
                                August 21, 1996
    
 
Board of Directors
WPL Holdings, Inc.
P.O. Box 2568
Madison, Wisconsin 53701-2568
 
Directors:
 
    WPL Holdings, Inc. ("WPL"), IES Industries Inc. ("IES"), Interstate Power
Company ("Interstate"), WPLH Acquisition Co., a wholly-owned subsidiary of WPL
("Acquisition"), and Interstate Power Company, a wholly-owned subsidiary of
Interstate, have entered into an agreement and plan of merger dated as of
November 10, 1995, as amended as of May 22, 1996 and as of August 16, 1996 (the
"Agreement") pursuant to which IES will be merged with and into WPL (the "IES
Merger"), and Acquisition will be merged with and into Interstate (the
"Interstate Merger" and together with the IES Merger, the "Merger"). In the IES
Merger, each issued and outstanding share of IES's common stock, no par value
(the "IES Shares"), shall be converted into the right to receive 1.14 shares of
the common stock, par value $.01 per share of WPL (the "WPL Shares"), and in the
Interstate Merger, each issued and outstanding share of Interstate's common
stock, par value $3.50 per share (the "Interstate Shares"), shall be converted
into the right to receive 1.11 WPL Shares. The ratio at which IES Shares are
converted into WPL Shares, in accordance with the Agreement, is referred to
herein as the "IES Ratio", and the ratio at which Interstate Shares are
converted into WPL Shares, in accordance with the Agreement, is referred to
herein as the "Interstate Ratio." The IES Ratio and Interstate Ratio together
are referred to herein as the "Conversion Ratios." Consummation of the Merger is
subject to the terms and conditions set forth in the Agreement. The Agreement
also provides for an alternative transaction structure, to satisfy certain
regulatory requirements, in the event the structure described above does not
comply with such regulatory requirements. In connection with the Merger, WPL,
IES and Interstate also have entered into six agreements dated as of November
10, 1995, as amended as of May 22, 1996 (the "Stock Option Agreements") pursuant
to which each of WPL, IES, and Interstate, respectively, has granted to the
others an option to purchase shares of its common stock on the terms and
conditions provided in such agreements, representing in the aggregate 19.9% of
the total issued and outstanding shares of each company as of November 10, 1995.
 
    You have asked us whether, in our opinion, the Conversion Ratios
contemplated by the Agreement are fair to WPL from a financial point of view.
 
    In arriving at the opinion set forth below, we have, among other things:
 
    (1) Reviewed WPL's Annual Reports, Forms 10-K and related financial
        information for the three fiscal years ended December 31, 1995 and WPL's
        Form 10-Q and the related unaudited financial information for the
        quarterly periods ending March 31, 1996 and June 30, 1996;
 
                                      II-1
<PAGE>
    (2) Reviewed IES's Annual Reports, Forms 10-K and related financial
        information for the three fiscal years ended December 31, 1995 and IES's
        Form 10-Q and the related unaudited financial information for the
        quarterly periods ending March 31, 1996 and June 30, 1996;
 
    (3) Reviewed Interstate's Annual Reports, Forms 10-K and related financial
        information for the three fiscal years ended December 31, 1995 and
        Interstate's Form 10-Q and the related unaudited financial information
        for the quarterly periods ending March 31, 1996 and June 30, 1996;
 
    (4) Reviewed certain other filings with the Securities and Exchange
        Commission made by WPL, IES and Interstate, including proxy statements,
        Forms 8-K and registration statements, during the last three years;
 
    (5) Reviewed certain information, including financial forecasts, relating to
        the business, earnings, dividends, cash flow, assets and prospects of
        WPL, IES, and Interstate, furnished to us by WPL, IES, and Interstate,
        respectively;
 
    (6) Conducted discussions with members of senior management of WPL, IES and
        Interstate concerning their respective businesses, regulatory
        environments, prospects and strategic objectives and possible operating,
        administrative and capital synergies which might be realized for the
        combined companies following the Merger;
 
    (7) Reviewed the historical market prices and trading activity for WPL
        Shares, IES Shares, Interstate Shares and Class A common stock of
        McLeod, Inc.;
 
    (8) Compared the results of operations of WPL, IES and Interstate with that
        of certain companies which we deemed to be reasonably similar to WPL,
        IES and Interstate, respectively;
 
    (9) Compared the proposed financial terms of the Merger with the financial
        terms of certain other mergers and acquisitions which we deemed to be
        relevant;
 
   (10) Analyzed the relative valuation of WPL Shares, IES Shares and Interstate
        Shares using various valuation methodologies which we deemed
        appropriate;
 
   (11) Considered the pro forma effect of the Merger, in terms of net income
        available to common stockholders, dividends per common share, book value
        per share and capitalization, on WPL Shares;
 
   (12) Reviewed the Agreement;
 
   (13) Reviewed the Stock Option Agreements; and
 
   (14) Reviewed such other financial studies and analyses and made such other
        inquiry and took into account such other matters as we deemed necessary
        or appropriate.
 
    In preparing our opinion, we have relied on the accuracy and completeness of
all information supplied or otherwise made available to us by WPL, IES and
Interstate, and we have not independently verified such information or any
underlying assumptions, conducted a physical inspection of the properties or
facilities of WPL, IES or Interstate, or undertaken or obtained any evaluation
or independent appraisal of the assets or liabilities (contingent or otherwise)
of WPL, IES or Interstate. We have assumed that the financial forecasts and
projected synergies furnished by WPL, IES and Interstate have been reasonably
prepared in accordance with accepted industry practices and reflect the best
currently available estimates and judgment of WPL's, IES's and Interstate's
management as to the expected future financial performance of WPL, IES and
Interstate, respectively, and as to the expected future projected outcomes of
various legal, regulatory and other contingencies. We have also assumed that the
Merger will be free of Federal tax to WPL, Acquisition, IES, Interstate and the
respective holders of WPL Shares, IES Shares
 
                                      II-2
<PAGE>
and Interstate Shares, and we further assume that the Merger will be accounted
for as a pooling of interests. Our opinion is based upon general economic,
market, monetary and other conditions as they exist and can be evaluated, and
the information made available to us, as of the date hereof.
 
    We have, in the past, provided financial advisory and financing services to
WPL, its subsidiary Wisconsin Power and Light Company, IES, its subsidiary IES
Utilities Inc., and Interstate and have received fees for the rendering of such
services. In addition, in the ordinary course of our securities business, we may
actively trade debt and equity securities of WPL, its subsidiary Wisconsin Power
and Light Company, IES, its subsidiary IES Utilities Inc., and Interstate for
our own account and the accounts of our customers, and we therefore may from
time to time hold a long or short position in such securities.
 
    This opinion has been prepared for the confidential use of WPL's Board of
Directors and may not be reproduced, summarized, described or referred to
without Merrill Lynch's prior written consent.
 
    On the basis of, and subject to the foregoing, we are of the opinion that
the Conversion Ratios contemplated by the Agreement are fair to WPL from a
financial point of view.
 
                                       Very truly yours,
                                       MERRILL LYNCH, PIERCE, FENNER & SMITH
                                                    INCORPORATED
 
                                      II-3
<PAGE>
                       MORGAN STANLEY & CO. INCORPORATED
 
                                                                       ANNEX III
 
   
                                                                 August 21, 1996
    
Board of Directors
IES Industries Inc.
IES Tower
200 First Street, S.E.
Cedar Rapids, IA 52401
 
Members of the Board of Directors
 
    We understand that IES Industries Inc. ("IES" or the "Company"), WPL
Holdings, Inc., which upon or immediately prior to consummation of the Merger
(as hereinafter defined) is proposed to be renamed Interstate Energy Corporation
("WPL"), Interstate Power Company ("IPC") and WPLH Acquisition Co., a wholly
owned subsidiary of WPL ("Merger Sub") have entered into an Agreement and Plan
of Merger, dated as of November 10, 1995, and subsequently have entered into
amendments thereto, dated as of May 22, 1996 and August 16, 1996 (as amended,
the "Merger Agreement"), which provides, among other things, for (i) the merger
of the Company with and into WPL (the "IES Merger") and (ii) the merger of
Merger Sub with and into IPC (the "IPC Merger" and, together with the IES
Merger, the "Merger"). Pursuant to the Merger, (i) WPL will be the surviving
corporation of the IES Merger and each issued and outstanding share of common
stock, no par value, of the Company (the "Company Common Stock"), other than
shares held in treasury or held by WPL or IPC or any of their subsidiaries or as
to which dissenters' rights have been perfected, will be converted into the
right to receive 1.14 shares (the "IES Ratio") of common stock, par value $.01
per share of WPL (the "WPL Common Stock"); and (ii) IPC will become a wholly
owned subsidiary of WPL and each issued and outstanding share of common stock,
par value $3.50 per share, of IPC (the "IPC Common Stock"), other than shares
held in treasury or held by WPL or the Company or any of their subsidiaries,
will be converted into the right to receive 1.11 shares (the "IPC Ratio") of WPL
Common Stock. It is also our understanding that the Company, WPL and IPC have
entered into Stock Option Agreements, each dated as of November 10, 1995, as
amended (the "Option Agreements"), which provide, among other things, for the
grant by the Company to each of WPL and IPC of an option to acquire certain
shares of Company Common Stock, the grant by WPL to each of the Company and IPC
to acquire certain shares of WPL Common Stock, and the grant by IPC to each of
the Company and WPL of an option to acquire certain shares of IPC Common Stock,
in each case, upon the terms and conditions provided in such agreements
(collectively, the "Options"). We further understand that the Merger Agreement
provides for an alternative transaction structure, to satisfy certain regulatory
requirements, in the event the structure outlined above does not comply with
such regulatory requirements. The terms and conditions of the Merger and Options
are more fully set forth in the Merger Agreement and Option Agreements,
respectively.
 
    We further understand that on August 4, 1996 MidAmerican Energy Company
("MidAmerican") made an unsolicited proposal to acquire all of the outstanding
shares of Company Common Stock (the "Acquisition Proposal"). Pursuant to the
Acquisition Proposal, the Company would merge with and into MidAmerican or a
subsidiary of MidAmerican and the holders of each issued and outstanding share
of Company Common Stock would have the right to elect to receive either (i)
$39.00 in cash or (ii) 2.346 shares of common stock of MidAmerican; provided
that the cash consideration may not exceed 40% of the aggregate consideration
paid.
 
    You have asked for our opinion as to whether the IES Ratio, taking into
account the IPC Ratio, is fair from a financial point of view to the holders of
shares of the Company Common Stock. As you are aware, we have previously
rendered a financial opinion letter dated July 11, 1996 in connection with the
Merger.
 
                                     III-1
<PAGE>
    For purposes of the opinion set forth herein, we have:
 
            (i)
            analyzed certain publicly available statements and other information
            of the Company, WPL and IPC, respectively;
 
           (ii)
            analyzed certain internal financial statements and other financial
            and operating data concerning the Company, WPL and IPC prepared by
    their respective managements;
 
          (iii)
            analyzed certain financial projections of the Company, WPL and IPC
            prepared by their respective managements;
 
           (iv)
            reviewed certain public research reports concerning IES, WPL and IPC
            prepared by certain equity research analysts and discussed these
    research reports, including financial projections contained therein, with
    the managements of IES, WPL and IPC, respectively;
 
            (v)
            discussed the past and current operations and financial condition
            and the prospects of the Company, WPL and IPC with senior executives
    of the Company, WPL and IPC, respectively;
 
           (vi)
            reviewed the reported prices and trading activity of each of the
            Company Common Stock, WPL Common Stock, IPC Common Stock and the
    Class A common stock of McLeod, Inc. ("McLeod");
 
          (vii)
            compared the financial performance of the Company, WPL and IPC and
            the prices and trading activity of the Company Common Stock, WPL
    Common Stock and IPC Common Stock with that of certain other comparable
    publicly traded companies and their securities;
 
         (viii)
            reviewed the financial terms, to the extent publicly available, of
            certain comparable merger or acquisition transactions;
 
           (ix)
            analyzed the pro forma financial impact of the Merger on the
            Company;
 
            (x)
            participated in discussions and negotiations among representatives
            of the Company, WPL and IPC and their respective financial and legal
    advisors;
 
           (xi)
            reviewed the Merger Agreement, the Option Agreements and certain
            related documents;
 
          (xii)
            reviewed and discussed with the Company, WPL and IPC an analysis
            prepared by the Company, WPL and IPC with the assistance of a third
    party consultant to the Company, WPL and IPC regarding estimates of the
    amount and timing of the potential cost savings to be derived from the
    Merger;
 
         (xiii)
            reviewed the registration statements filed on Form S-1, dated May
            15, 1996 and on June 10, 1996, respectively, regarding the initial
    public offering of Class A common stock of McLeod (the "McLeod IPO"), as
    well as the Investor Agreement among various parties, including McLeod, IES
    Investments Inc., Midwest Capital Group Inc., MWR Investments, Inc. and
    Clark and Mary McLeod, entered into as April 1, 1996 which, among other
    things, sets forth certain restrictions on the transfer of McLeod common
    stock owned by the Company;
 
          (xiv)
            reviewed certain information pertaining to McLeod and the McLeod IPO
            provided by the Company and discussed certain aspects of such
    information with the management of the Company; and
 
           (xv)
            performed such other analyses and examinations and considered such
            other factors as we have deemed appropriate.
 
    We have assumed and relied upon without independent verification the
accuracy and completeness of the information reviewed by us for the purpose of
this opinion. With respect to the financial projections and the estimates of the
potential cost savings to be derived from the Merger, we have assumed that such
projections and estimates have been reasonably prepared on bases reflecting the
best currently available estimates and judgments of the future financial
performance of the Company,
 
                                     III-2
<PAGE>
   
WPL and IPC, respectively, and of the amount and timing of such cost savings. We
have also relied upon, with your consent, the Company's assessment of the
strategic and other benefits of the Merger. We have not made any independent
valuation or appraisal of the assets or liabilities of the Company, WPL and IPC.
In addition, we did not address the relative merits of the Merger and the
Acquisition Proposal or any other alternative potential transactions. We assumed
that the Merger will be consummated in accordance with the terms set forth in
the Merger Agreement, including, among other things, that the Merger will be
accounted for as a "pooling-of-interests" business combination in accordance
with U.S. generally accepted accounting principles and that the Merger will be
treated as a tax-free reorganization and/or exchange, each pursuant to the
Internal Revenue Code of 1986. Our opinion is necessarily based on economic,
market and other conditions as in effect on, and the information made available
to us as of, the date hereof.
    
 
    In arriving at our opinion, we have assumed that in connection with the
receipt of all the necessary regulatory and governmental approvals for the
proposed Merger, no restriction will be imposed that would have a material
adverse effect on the contemplated benefits expected to be derived in the
proposed Merger. In addition, we were not authorized to solicit, and did not
solicit, interest from any party with respect to a merger with or other business
combination transaction involving the Company or any of its assets, nor did we
have any discussions or negotiations with any parties, other than WPL and IPC,
in connection with the Merger.
 
    We have acted as financial advisor to the Board of Directors of the Company
in connection with this transaction and will receive a fee for our services. In
the past, Morgan Stanley & Co. Incorporated and its affiliates ("Morgan
Stanley") have provided financial advisory and financing services for the
Company and WPL and have received fees for the rendering of these services.
Morgan Stanley acted as co-lead manager of the McLeod IPO.
 
    It is understood that this letter is for the information of the Board of
Directors of the Company and may not be used for any other purpose without our
prior written consent, except that this opinion may be included in its entirety
in any filing made by the Company with the Securities and Exchange Commission
with respect to the Merger and the transactions related thereto. In addition, we
express no recommendation as to how the shareholders of the Company should vote
at the shareholders' meeting held in connection with the Merger.
 
    Based on the foregoing, we are of the opinion on the date hereof that the
IES Ratio, taking into account the IPC Ratio, is fair from a financial point of
view to the holders of shares of the Company Common Stock.
 
                                          Very truly yours,
 
                                          MORGAN STANLEY & CO. INCORPORATED
 
                                          By: /s/ ROBERT W. JONES
 
                                             -----------------------------------
                                              Robert W. Jones
                                              Managing Director
 
                                     III-3
<PAGE>
                                                                        ANNEX IV
 
Salomon Brothers Inc
 
   
August 21, 1996
    
 
Board of Directors
Interstate Power Company
1000 Main Street
Post Office Box 769
Dubuque, IA 52004-0769
Dear Sirs:
 
    You have requested our opinion as to the fairness, from a financial point of
view, to the holders of common stock, par value $3.50 per share ("Company Common
Stock"), of Interstate Power Company, a Delaware corporation (the "Company"),
other than WPL Holdings, Inc. ("WPL"), IES Industries Inc. ("IES") or any of
their respective affiliates, of the exchange ratio to be used for the conversion
of Company Common Stock in connection with the proposed combination (the
"Combination") of the Company, WPL and IES pursuant to the Agreement and Plan of
Merger dated as of November 10, 1995, as amended (the "Merger Agreement"), by
and among WPL, IES, the Company, WPLH Acquisition Co., a wholly owned subsidiary
of WPL ("Acquisition"), and Interstate Power Company, a wholly owned subsidiary
of the Company and a Wisconsin corporation ("New IPC"). In the Combination, IES
will merge into WPL, which will be the surviving corporation in the Combination,
and either (x) Acquisition will merge into the Company, with the Company to be
the surviving corporation and a wholly owned subsidiary of WPL, or (y) in the
event certain regulatory requirements mandate that the utility subsidiaries of
WPL be Wisconsin corporations, the Company will merge into New IPC and then
Acquisition will merge into New IPC, with New IPC to be the surviving
corporation and a wholly owned subsidiary of WPL. As a result of the foregoing,
WPL (which will change its name to Interstate Energy Corporation) will be a
holding company with three operating utilities as subsidiaries. In the
Combination, each issued and outstanding share of Company Common Stock, other
than shares owned by the Company, WPL, IES or any of their respective
subsidiaries, will be converted into 1.11 shares (the "Company Exchange Ratio")
of common stock, par value of $0.01 per share ("WPL Common Stock"), of WPL. Each
issued and outstanding share of common stock, no par value, of IES, other than
shares owned by IES, WPL, the Company or any of their respective subsidiaries,
will be converted into 1.14 shares of WPL Common Stock. We understand the
Combination is intended to be accounted for as a pooling of interests in
accordance with generally accepted accounting principles as described in
Accounting Principles Board Opinion Number 16.
 
    In arriving at our opinion, we have reviewed the Merger Agreement, its
related exhibits and the Joint Proxy Statement/Prospectus dated July 11, 1996
and the Supplement to such Joint Proxy Statement/Prospectus dated the date
hereof, in each case relating to the Combination. We also have reviewed certain
publicly available business and financial information relating to the Company,
WPL and IES, as well as certain other information, including financial
projections, provided to us by the Company, WPL and IES. We have discussed the
past and current operations and financial condition and prospects of the
Company, WPL and IES with their respective senior management. We also have
considered such other information, financial studies, analyses, investigations
and financial, economic, market and trading criteria which we deemed relevant,
including the amended registration statement on Form S-1 filed by McLeod, Inc.
(a Delaware corporation in which IES has a significant ownership interest).
 
    We have assumed and relied on the accuracy and completeness of the
information reviewed by us for the purpose of this opinion and we have not
assumed any responsibility for independent verification of such information or
for independent evaluation or appraisal of the assets of the Company, WPL or
IES. With respect to the financial projections of the Company, WPL and IES, we
have assumed that
 
                                      IV-1
<PAGE>
Board of Directors
Interstate Power Company
Page 2
they have been reasonably prepared on bases reflecting the best currently
available estimates and judgments of the management of the Company, WPL or IES,
as the case may be, as to the future financial performance of such entity, and
we express no opinion with respect to such forecasts or the assumptions on which
they are based.
 
    Our opinion is necessarily based upon business, market, economic and other
conditions as they exist on, and can be evaluated as of, the date of this letter
and does not address the Company's underlying business decision to enter into
the Combination or constitute a recommendation to any holder of Company Common
Stock as to how such holder should vote with respect to the Combination. We were
not requested to, and did not, solicit third party offers to acquire all or any
part of the Company. Our opinion as expressed below does not imply any
conclusion as to the likely trading range for WPL Common Stock following the
consummation of the Combination, which may vary depending on, among other
factors, changes in interest rates, dividend rates, market conditions, general
economic conditions and other factors that generally influence the price of
securities.
 
    We have acted as financial advisor to the Board of Directors of the Company
in connection with the Combination and will receive a fee for our services, the
payment of a portion of which is contingent upon the consummation of the
Combination. Additionally, we have acted as underwriter for the Company in
connection with three of its prior financings, as well as lead manager for the
initial public offering by McLeod, Inc. In the ordinary course of our business,
we actively trade the debt and equity securities of the Company, WPL and IES for
our own account and for the accounts of customers and, accordingly, may at any
time hold a long or short position in such securities.
 
    Based upon and subject to the foregoing, it is our opinion that, as of the
date hereof, the Company Exchange Ratio is fair from a financial point of view
to the holders of Company Common Stock (other than WPL, IES or any of their
respective affiliates).
 
Very truly yours,
 
Salomon Brothers Inc
 
                                      IV-2
<PAGE>
                        [WPL HOLDINGS, INC. LETTERHEAD]
                                                            ERROLL B. DAVIS, JR.
                                                             PRESIDENT AND CHIEF
                                                               EXECUTIVE OFFICER
 
                                                                   July 23, 1996
 
Dear WPL Holdings, Inc. Shareowner:
 
    We  extend a cordial invitation to you to join us at the 1996 Annual Meeting
of Shareowners of WPL Holdings, Inc.  ("WPLH"). The WPLH Annual Meeting will  be
held  immediately following the Annual Meeting of Shareowners of Wisconsin Power
and Light Company at the  Exhibition Hall at the  Dane County Expo Center,  1881
Expo  Mall, Madison,  Wisconsin, on  September 5,  1996, at  10:00 a.m. (Central
Time). A lunch will be served following the meeting.
 
    At this important meeting, the WPLH  shareowners will be asked to approve  a
strategic  three-way business  combination among WPLH,  Cedar Rapids, Iowa-based
IES Industries Inc.  ("IES") and  Dubuque, Iowa-based  Interstate Power  Company
("IPC").  WPLH, as the surviving holding company in the merger transaction, will
be renamed Interstate Energy Corporation.
 
    The utility  industry continues  to  undergo rapid  change and  is  becoming
increasingly  competitive. This new environment, driven by regulatory changes at
the federal  and  state levels  and  by  technological advances,  has  and  will
continue  to alter in a  fundamental way the manner  in which the entire utility
industry does  business. Your  Board  of Directors  believes that  the  proposed
combination  with IES and  IPC will result  in a combined  business that will be
well-positioned to compete in this new environment.
 
    Following consummation of the mergers, each  share of WPLH common stock  you
own will represent one share of Interstate Energy Corporation common stock. AS A
SHAREOWNER  OF WPLH, YOU WILL NOT NEED TO EXCHANGE YOUR WPLH STOCK CERTIFICATES.
In the mergers,  each share  of IES  common stock  will be  converted into  1.01
shares  of  Interstate Energy  Corporation common  stock and  each share  of IPC
common stock will be converted into 1.11 shares of Interstate Energy Corporation
common stock.  As  described in  greater  detail  in the  attached  Joint  Proxy
Statement/Prospectus,  the shares of WPLH common stock issued in the mergers are
expected to have attached  thereto associated rights  to purchase common  stock.
Your  Board has received  a written opinion from  its financial advisor, Merrill
Lynch, Pierce, Fenner & Smith Incorporated,  dated November 10, 1995, which  was
confirmed  in  a written  opinion dated  the  date of  the attached  Joint Proxy
Statement/Prospectus, to the effect that, as  of such dates, and based upon  the
assumptions  made, matters considered and limits of  review as set forth in such
opinions, the  foregoing  exchange ratios,  taken  together, are  fair,  from  a
financial  point of view, to WPLH. Wisconsin law does not provide shareowners of
WPLH with statutory dissenters' rights in connection with the mergers.
 
    Approval of the combination by the shareowners of WPLH, IES and IPC entitled
to vote  thereon  is  a condition  to  the  completion of  the  transaction.  In
addition,  the  transaction will  be consummated  only after  certain regulatory
approvals are received  and other  conditions are  satisfied or  waived. If  all
required  approvals are received, it is  presently anticipated that the proposed
combination will be completed during the first half of 1997.
 
    At the WPLH Annual Meeting, you will also be asked to consider and vote upon
certain proposed amendments to the  Restated Articles of Incorporation of  WPLH,
the election of three directors for terms expiring at the 1999 Annual Meeting of
Shareowners, and the appointment of Arthur Andersen
<PAGE>
LLP  as the independent auditors of WPLH  for the year ending December 31, 1996.
The amendments to the Restated Articles are necessary to effect the name  change
from  WPLH to Interstate Energy Corporation and to ensure that Interstate Energy
Corporation will have sufficient authorized but unissued shares of common  stock
to  complete the proposed  combination, as well as  to provide Interstate Energy
Corporation with the  flexibility to issue  shares in the  future when the  need
arises  without the delay  of having to obtain  shareowner approval to authorize
the issuance if not otherwise required.
 
    Each of  the  proposals to  be  considered at  the  WPLH Annual  Meeting  is
described  in  greater  detail  in  the  accompanying  Notice  and  Joint  Proxy
Statement/Prospectus and its various attachments. I encourage you to read  these
materials carefully.
 
    THE  BOARD OF  DIRECTORS OF WPLH  HAS CAREFULLY REVIEWED  AND CONSIDERED THE
TERMS AND  CONDITIONS OF  THE PROPOSALS  TO BE  VOTED UPON  AT THE  WPLH  ANNUAL
MEETING  AND  BELIEVES THAT  THEY  ARE IN  THE BEST  INTERESTS  OF WPLH  AND ITS
SHAREOWNERS, AND UNANIMOUSLY RECOMMENDS THAT SHAREOWNERS VOTE "FOR" EACH OF  THE
PROPOSALS DESCRIBED IN THE ATTACHED JOINT PROXY STATEMENT/PROSPECTUS.
 
    Your  vote is important no  matter how many shares  you hold. Whether or not
you plan to attend the WPLH Annual  Meeting, please fill out, sign and date  the
enclosed  proxy card, and return it promptly in the accompanying envelope, which
requires no postage if mailed  in the United States. If  you plan to join us  at
the  WPLH Annual Meeting, please indicate the  names of the individuals who will
be attending  on  the  enclosed  proxy  card  reservation  form.  To  help  with
directions  to the site  for the WPLH Annual  Meeting, a map  is provided on the
last page of this document for your reference. Parking will be available to  you
at no charge.
 
    If  you  have  any questions  about  the  WPLH Annual  Meeting,  please call
Shareowner Services at 608-252-3110 (local) or 1-800-356-5343 (toll-free).
 
                                          Sincerely,
 
                                            [/S/ ERROLL B. DAVIS, JR.]
                                          Erroll B. Davis, Jr.
                                          PRESIDENT AND CHIEF EXECUTIVE OFFICER
<PAGE>
                        [IES Industries Inc. Letterhead]
 
Dear IES Industries Inc. Shareholder:
 
    You  are cordially invited  to attend the Annual  Meeting of Shareholders of
IES Industries Inc. ("IES") which will  be held on Thursday, September 5,  1996,
at the Collins Plaza Hotel, 1200 Collins Road N.E., Cedar Rapids, Iowa, at 10:00
a.m. (Central Time).
 
    At  this meeting, the IES Shareholders will  be asked to approve a strategic
three-way business  combination  among  IES, WPL  Holdings,  Inc.  ("WPLH")  and
Interstate  Power  Company  ("IPC"). The  new  holding company  will  be renamed
Interstate Energy Corporation.
 
    Your Board of Directors expects the utility industry to undergo rapid change
over the  next several  years, becoming  increasingly competitive.  Federal  and
state  regulatory  changes  and  technological  advances  will  have fundamental
effects on the entire utility industry.
 
    Your Board of Directors believes the  combination of IES, WPLH and IPC  will
result in a strong business organization able to take advantage of opportunities
in both its core utility and its diversified businesses.
 
    In the proposed transaction, each outstanding share of IES Common Stock will
be  converted  into 1.01  shares  of Interstate  Energy  Common Stock  (the "IES
Ratio"). In  addition,  each outstanding  share  of  IPC Common  Stock  will  be
converted  into 1.11 shares of Interstate Energy Common Stock (the "IPC Ratio").
As described in greater detail in the attached Joint Proxy Statement/Prospectus,
the shares  of Interstate  Energy Common  Stock issued  in the  transaction  are
expected to have attached thereto associated rights to purchase common stock. On
November  10, 1995,  your Board  of Directors received  the oral  opinion of its
financial advisor, Morgan Stanley & Co.  Incorporated, which was confirmed in  a
written   opinion  dated   as  of   the  date   of  the   attached  Joint  Proxy
Statement/Prospectus, to the effect that, as  of such dates, and based upon  the
procedures  and subject  to the  assumptions described  therein, the  IES Ratio,
taking into account the IPC Ratio, is fair from a financial point of view to the
holders of IES Common Stock.  The transaction requires, among other  conditions,
certain  regulatory approvals,  as well  as the  approval of  IES, WPLH  and IPC
shareholders.
 
    THE IES BOARD OF DIRECTORS HAS  CAREFULLY REVIEWED AND CONSIDERED THE  TERMS
AND  CONDITIONS OF  THE MERGER TO  BE VOTED UPON  AT THE IES  ANNUAL MEETING AND
BELIEVES IT IS IN THE BEST INTERESTS OF IES AND ITS SHAREHOLDERS AND  RECOMMENDS
THAT SHAREHOLDERS VOTE "FOR" THE PROPOSALS DESCRIBED IN THE ATTACHED JOINT PROXY
STATEMENT/PROSPECTUS.
 
    In addition, IES Shareholders will be asked to elect nine directors to serve
until  the next annual meeting of IES Shareholders or until their successors are
elected and qualified.
 
    You have, as an IES  Shareholder, the right under  Iowa law to dissent  from
and  obtain  the  "fair  value"  of  your IES  Common  Stock  in  the  event the
transaction contemplated by the  Merger Agreement is completed.  If you wish  to
assert  your  dissenters' rights,  you  must give  notice  to IES  prior  to the
shareholder meeting  and  not  vote in  favor  of  the merger.  Please  see  the
discussion   of  your  dissenters'  rights   in  the  accompanying  Joint  Proxy
Statement/Prospectus.
 
    A map showing the location of the Annual Meeting of Shareholders is  printed
on  the last  page of  this Joint  Proxy Statement/Prospectus.  A notice  of the
meeting and a proxy/directions  card are enclosed. We  hope you will sign,  date
and  return the  proxy/directions card as  promptly as possible  in the enclosed
self-addressed postage prepaid envelope.  As a Shareholder, it  is in your  best
interest, as well as helpful to your Board of Directors, that you participate in
the affairs of IES, whether you own a few shares or many shares.
 
    A  copy of the Annual Report of  IES, including financial statements for the
year ended December 31, 1995, has previously  been sent to you. A report of  the
Annual Meeting will be mailed to all Shareholders following the meeting.
 
    Please  let me  express my  appreciation for  your past  cooperation. I look
forward to your continued interest in IES.
<PAGE>
    Whether or  not you  plan  to attend  the  Annual Meeting,  please  promptly
complete,  sign,  date  and return  the  enclosed proxy/directions  card  in the
enclosed postage prepaid envelope. You may, of course, attend the Annual Meeting
and vote in person, even if you have previously returned your proxy card. If you
have any questions  about the IES  Annual Meeting, please  call IES  Shareholder
Services at (319) 398-7755 or (800) 247-9785 (toll-free).
 
    On behalf of your Board of Directors, thank you for your continued support.
 
                                          Sincerely,
 
                                                [/S/ LEE LIU]
                                          LEE LIU
                                          CHAIRMAN OF THE BOARD, PRESIDENT &
                                          CHIEF EXECUTIVE OFFICER
 
July 23, 1996
<PAGE>
                     [INTERSTATE POWER COMPANY LETTERHEAD]
                                                            WAYNE H. STOPPELMOOR
                                                          CHAIRMAN OF THE BOARD,
                                                             PRESIDENT AND CHIEF
                                                               EXECUTIVE OFFICER
 
                                 July 23, 1996
 
Dear Interstate Power Company Stockholder:
 
    You  are cordially invited  to attend the Annual  Meeting of Stockholders of
Interstate Power Company ("IPC")  which will be held  on Thursday, September  5,
1996,  at the Holiday Inn Dubuque Five  Flags, 450 Main Street, Dubuque, Iowa at
10:00 a.m. (Central Time).
 
    At this important  meeting, holders  of IPC Common  Stock will  be asked  to
approve  a strategic  three-way business  combination among  IPC, IES Industries
Inc. ("IES") based in Cedar Rapids, Iowa, and WPL Holdings, Inc. ("WPLH")  based
in  Madison, Wisconsin. The resulting entity  in this three-way combination will
be named Interstate Energy Corporation. Holders  of IPC Preferred Stock are  not
entitled to vote on the three-way combination.
 
    The utility industry is in the midst of fundamental change fueled by federal
and state regulatory shifts and technological advances. These changes are moving
the  utility industry  into an era  of unprecedented competition.  Your Board of
Directors believes the proposed combination with  WPLH and IES will result in  a
strong  organization well positioned to take  advantage of opportunities in this
new environment.
 
    In the  mergers,  each share  of  IPC Common  Stock  that you  own  will  be
converted  into 1.11 shares  of common stock of  the combined entity, Interstate
Energy Corporation. In addition, each outstanding share of IES Common Stock will
be converted into 1.01 shares of common stock of Interstate Energy  Corporation.
As described in greater detail in the attached Joint Proxy Statement/Prospectus,
the  shares  of common  stock  of Interstate  Energy  Corporation issued  in the
mergers are  expected to  have attached  thereto associated  rights to  purchase
common stock.
 
    As an important part of the mergers, and in order to ensure that the mergers
qualify  for tax-free reorganization treatment  under the Internal Revenue Code,
holders of IPC Common Stock will be asked to consider and vote upon the approval
of an  amendment  to IPC's  Restated  Certificate of  Incorporation  which  will
provide  that  each share  of IPC  Preferred  Stock will  have one  vote, voting
together as one class with the holders of IPC Common Stock (except as  otherwise
required  by  law or  as specifically  provided in  the Restated  Certificate of
Incorporation), on all matters to come before a vote of the stockholders of IPC.
 
    Under Delaware law, holders of IPC Preferred Stock who do not wish to accept
the consideration  to  be provided  them  in  connection with  the  mergers  are
entitled  to  an appraisal  of the  fair value  of such  holder's shares  by the
Delaware courts. Holders of IPC Common Stock are not entitled to an appraisal of
their shares. Please read the Joint Proxy Statement/Prospectus for a description
of the procedural requirements to be followed to perfect appraisal rights.
<PAGE>
    In addition, holders of IPC Common Stock will be asked to elect two Class II
directors to hold office for a term  of three years expiring at the 1999  annual
meeting  of IPC stockholders,  and until their  respective successors shall have
been duly elected and qualified.
 
    Each of  the  proposals  to be  considered  at  the IPC  Annual  Meeting  is
described  in greater  detail in  the accompanying  Notice of  Meeting and Joint
Proxy Statement/Prospectus and its various attachments. I encourage you to  read
these materials carefully.
 
    YOUR BOARD OF DIRECTORS HAS CAREFULLY CONSIDERED THE TERMS AND CONDITIONS OF
THE  MERGERS AND THE OTHER PROPOSALS TO BE  VOTED UPON AT THE IPC ANNUAL MEETING
AND BELIEVES THEY ARE  IN THE BEST  INTERESTS OF IPC  AND ITS STOCKHOLDERS,  AND
UNANIMOUSLY  RECOMMENDS  THAT  STOCKHOLDERS  VOTE "FOR"  EACH  OF  THE PROPOSALS
DESCRIBED IN THE ATTACHED JOINT PROXY STATEMENT/PROSPECTUS.
 
    A copy of the Annual Report  of IPC, including financial statements for  the
fiscal year ended December 31, 1995, has previously been sent to you.
 
    Your  vote is important no  matter how many shares  you hold. WHETHER OR NOT
YOU PLAN TO ATTEND THE ANNUAL MEETING, PLEASE PROMPTLY COMPLETE, SIGN, DATE  AND
RETURN  THE ENCLOSED PROXY IN THE ENCLOSED POSTAGE PREPAID ENVELOPE. You may, of
course, attend  the  Annual  Meeting  and  vote in  person,  even  if  you  have
previously returned your proxy.
 
    If  you have any questions regarding the IPC Annual Meeting, please call IPC
Stockholder Services at (319) 582-5421, ext. 465.
 
    On behalf of your Board of Directors, thank you for your continued support.
 
                                          Sincerely,
 
                                      [/S/ WAYNE H. STOPPELMOOR]
                                          Wayne H. Stoppelmoor
                                          CHAIRMAN OF THE BOARD, PRESIDENT AND
                                          CHIEF EXECUTIVE OFFICER
<PAGE>
                                 [LOGO]
 
                            ------------------------
 
                    NOTICE OF ANNUAL MEETING OF SHAREOWNERS
        DIRECTLY FOLLOWING THE 10:00 A.M. ANNUAL MEETING OF SHAREOWNERS
            OF WISCONSIN POWER AND LIGHT COMPANY, SEPTEMBER 5, 1996
                            ------------------------
 
    The  Annual  Meeting  of  Shareowners of  WPL  Holdings,  Inc.,  a Wisconsin
corporation ("WPLH"), will  be held at  the Exhibition Hall  at the Dane  County
Expo  Center, 1881 Expo Mall, Madison, Wisconsin, on September 5, 1996, directly
following the  10:00  a.m.,  Central  Time, Annual  Meeting  of  Shareowners  of
Wisconsin  Power and Light Company, for the following purposes, all of which are
more fully described in the accompanying Joint Proxy Statement/Prospectus:
 
    1.  To consider and vote upon  a proposal to approve the Agreement and  Plan
       of  Merger, dated as  of November 10,  1995, as amended  (together with a
       related  Plan  of  Merger,  the  "Merger  Agreement"),  among  WPLH,  IES
       Industries Inc., an Iowa corporation ("IES"), Interstate Power Company, a
       Delaware   corporation  ("IPC"),   WPLH  Acquisition   Co.,  a  Wisconsin
       corporation and  wholly-owned subsidiary  of WPLH,  and Interstate  Power
       Company,  a Wisconsin corporation  and wholly-owned subsidiary  of IPC, a
       copy of which  is attached  as Annex A  to the  accompanying Joint  Proxy
       Statement/Prospectus,   and   the   transactions   contemplated  thereby,
       including, among other things, the issuance of shares of common stock  of
       WPLH  (to be renamed Interstate Energy Corporation) pursuant to the terms
       of the Merger Agreement.
 
    2.   To consider  and vote  upon a  proposal to  approve amendments  to  the
       Restated Articles of Incorporation of WPLH (a) to change the name of WPLH
       to Interstate Energy Corporation (the "Name Change Amendment") and (b) to
       increase  the number  of shares  of common  stock of  WPLH authorized for
       issuance from 100,000,000 to  200,000,000 ("the Common Stock  Amendment,"
       and   together  with  the  Name   Change  Amendment,  the  "WPLH  Charter
       Amendments").
 
    3.  To  elect a  total of  three directors for  terms expiring  at the  1999
       Annual Meeting of Shareowners.
 
    4.   To  appoint Arthur  Andersen LLP as  independent auditors  for the year
       ending December 31, 1996.
 
    5.  To  consider and  act upon  any other  business that  may properly  come
       before the meeting or any adjournment or postponement thereof.
 
    Only the holders of common stock of record on the books of WPLH at the close
of  business  on July  10, 1996,  are entitled  to  vote at  the meeting  or any
adjournment or postponement thereof.  All such shareowners  are requested to  be
present  at the meeting in person or by  proxy, so that the presence of a quorum
may be assured.
 
    Approval of proposals  1 and  2 are conditions  to the  consummation of  the
transactions  contemplated by the Merger  Agreement. If approved by shareowners,
each  of  the  WPLH  Charter  Amendments  will  become  effective  only  if  the
transactions  contemplated by the Merger Agreement are consummated. As described
in greater detail in the  attached Joint Proxy Statement/Prospectus, the  shares
of WPLH common stock issued in the mergers are expected to have attached thereto
associated rights to purchase common stock.
 
    PLEASE  SIGN AND RETURN  YOUR PROXY IMMEDIATELY. IF  YOU ATTEND THE MEETING,
YOU MAY WITHDRAW YOUR  PROXY AT THE  REGISTRATION DESK AND  VOTE IN PERSON.  ALL
SHAREOWNERS ARE URGED TO RETURN THEIR PROXIES PROMPTLY.
<PAGE>
    Your proxy covers all of your shares of common stock of WPLH. For present or
past employees of WPLH or Wisconsin Power and Light Company, your proxy includes
any  shares held for  your account under WPLH's  Dividend Reinvestment and Stock
Purchase Plan. For shares credited to  an account under the Wisconsin Power  and
Light  Company Employees' Retirement Savings  Plan (formerly the Employees' Long
Range Savings and Investment Plan),  you will receive a  form of proxy from  the
trustee of the plan.
 
    A copy of the 1995 Annual Report of WPLH has previously been sent to you.
 
                                          By Order of the Board of Directors
 
                                                [/S/ EDWARD M. GLEASON]
                                          Edward M. Gleason
                                          VICE PRESIDENT, TREASURER AND
                                          CORPORATE SECRETARY
 
Madison, Wisconsin
July 23, 1996
 
YOUR  VOTE IS IMPORTANT  NO MATTER HOW LARGE  OR SMALL YOUR  HOLDINGS MAY BE. TO
ASSURE YOUR  REPRESENTATION AT  THE  ANNUAL MEETING,  PLEASE DATE  THE  ENCLOSED
PROXY,  WHICH IS SOLICITED  BY THE BOARD  OF DIRECTORS OF  WPLH, SIGN EXACTLY AS
YOUR NAME APPEARS THEREON AND RETURN IMMEDIATELY.
<PAGE>
                              IES INDUSTRIES INC.
                               ------------------
 
                    NOTICE OF ANNUAL MEETING OF SHAREHOLDERS
                          TO BE HELD SEPTEMBER 5, 1996
 
To the Shareholders of IES INDUSTRIES INC.:
 
    The  Annual  Meeting  of  Shareholders  of  IES  Industries  Inc.,  an  Iowa
corporation ("IES"), will be held at the Collins Plaza Hotel, 1200 Collins  Road
N.E.,  Cedar Rapids,  Iowa, on the  5th day of  September, 1996, at  the hour of
10:00 a.m. (Central  Time) for  the following purposes,  all of  which are  more
fully described in the accompanying Joint Proxy Statement/Prospectus:
 
    1.   To consider and vote upon a  proposal to approve the Agreement and Plan
       of Merger, dated  as of November  10, 1995, as  amended (together with  a
       related Plan of Merger, the "Merger Agreement"), among IES, WPL Holdings,
       Inc.,  a  Wisconsin  corporation ("WPLH"),  Interstate  Power  Company, a
       Delaware  corporation  ("IPC"),   WPLH  Acquisition   Co.,  a   Wisconsin
       corporation  and wholly-owned  subsidiary of  WPLH, and  Interstate Power
       Company, a Wisconsin  corporation and wholly-owned  subsidiary of IPC,  a
       copy  of which  is attached  as Annex A  to the  accompanying Joint Proxy
       Statement/Prospectus.
 
    2.   To elect  a board  of nine  directors to  serve until  the next  annual
       meeting or until their successors are duly elected and qualified.
 
    3.   To transact such other business as may properly come before the meeting
       or at any adjournment or postponement thereof.
 
    The Board  of Directors,  in  accordance with  the  Bylaws and  Articles  of
Incorporation  of IES, has  fixed the close  of business, July  10, 1996, as the
record date for the determination of  shareholders entitled to notice of and  to
vote at this meeting and any adjournment or postponement thereof. Your continued
interest and cooperation are greatly appreciated.
 
    Approval  of the Merger Agreement is a  condition to the consummation of the
transactions contemplated  by  the Merger  Agreement.  As described  in  greater
detail  in the attached  Joint Proxy Statement/Prospectus,  the shares of common
stock to  be  issued pursuant  to  the Merger  Agreement  are expected  to  have
attached thereto associated rights to purchase common stock.
 
    Any shareholder has the right to dissent from and to obtain the "fair value"
of  such  shareholder's  shares  of  IES  Common  Stock  in  the  event  of  the
consummation of the transactions contemplated by the Merger Agreement,  provided
that  such shareholder perfects his or her dissenter's rights in accordance with
Sections 490.1301 through 490.1331 of the Iowa Business Corporation Act.  Please
see  the  discussion  of  dissenters' rights  in  the  accompanying  Joint Proxy
Statement/Prospectus and Sections 490.1301 through 490.1331, a copy of which  is
attached as Annex P to the Joint Proxy Statement/Prospectus.
 
    This Notice is sent to you by order of the Board of Directors.
 
                                             [/S/ STEPHEN W. SOUTHWICK]
                                          STEPHEN W. SOUTHWICK
                                          VICE PRESIDENT, GENERAL COUNSEL &
                                          SECRETARY
 
Cedar Rapids, Iowa
July 23, 1996
 
    THE  BYLAWS REQUIRE THAT THE HOLDERS OF A MAJORITY OF THE OUTSTANDING SHARES
OF STOCK ENTITLED TO VOTE BE REPRESENTED IN PERSON OR BY PROXY AT THE MEETING TO
CONSTITUTE A QUORUM FOR  THE TRANSACTION OF  BUSINESS. THEREFORE, REGARDLESS  OF
THE  NUMBER OF SHARES YOU HOLD, IT  IS IMPORTANT THAT YOUR SHARES BE REPRESENTED
AT THE MEETING.
    PLEASE SIGN, DATE AND MAIL THE  PROXY/DIRECTIONS CARD PROMPTLY IN THE  SELF-
ADDRESSED  ENVELOPE, WHICH REQUIRES  NO POSTAGE IF MAILED  IN THE UNITED STATES.
THE PROMPT RETURN OF YOUR PROXY/DIRECTIONS  CARD WILL SAVE THE EXPENSE  INVOLVED
IN FURTHER COMMUNICATION.
<PAGE>
                            INTERSTATE POWER COMPANY
 
                                1000 Main Street
                                  P.O. Box 769
                            Dubuque, Iowa 52004-0769
 
                    NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
 
TO THE HOLDERS OF COMMON STOCK OF
INTERSTATE POWER COMPANY:
 
    NOTICE  IS  HEREBY GIVEN  that  the annual  meeting  of the  stockholders of
Interstate Power Company, a  Delaware corporation ("IPC"), will  be held at  the
Holiday Inn Dubuque Five Flags, 450 Main Street, Dubuque, Iowa, on Thursday, the
fifth (5th) day of September, 1996, at ten o'clock in the morning, Central Time,
for the purpose of considering and voting with respect to the following matters,
all  of  which  are  more  fully  described  in  the  accompanying  Joint  Proxy
Statement/Prospectus:
 
    1.  To consider and vote upon  a proposal to approve the Agreement and  Plan
       of  Merger,  dated  as of  November  10,  1995, as  amended  (the "Merger
       Agreement"), among  IPC,  WPL  Holdings, Inc.,  a  Wisconsin  corporation
       ("WPLH"),   IES  Industries  Inc.,  an  Iowa  corporation  ("IES"),  WPLH
       Acquisition Co., a Wisconsin corporation and a wholly-owned subsidiary of
       WPLH, and  Interstate  Power  Company,  a  Wisconsin  corporation  and  a
       wholly-owned subsidiary of IPC, a copy of which is attached as Annex A to
       the  accompanying Joint Proxy Statement/ Prospectus. Each of the specific
       merger transactions to which IPC may be a party that are contemplated  by
       the  Merger Agreement  (including the IPC  Reincorporation Merger), which
       are   described   in   detail    in   the   accompanying   Joint    Proxy
       Statement/Prospectus,  requires  approval of  the  holders of  IPC common
       stock.
 
    2.  To consider and  vote upon a proposal to  approve an amendment to  IPC's
       Restated  Certificate  of Incorporation  to  provide that  each  share of
       preferred stock of IPC outstanding from time to time will have one  vote,
       voting  together as a class with the  holders of IPC common stock (except
       as otherwise provided by law or specifically set forth in IPC's  Restated
       Certificate  of Incorporation), on  all matters to come  before a vote of
       the stockholders of IPC.
 
    3.  The  election of two  Class II directors  to hold office  for a term  of
       three  years expiring at the 1999  annual meeting of stockholders of IPC,
       or until their  respective successors  shall have been  duly elected  and
       qualified.
 
    4.   The transaction of such other  business as may properly be presented to
       the meeting.
 
    In  accordance  with   the  provisions  of   the  Restated  Certificate   of
Incorporation,  as amended, and  the By-Laws, as  amended, of IPC,  the Board of
Directors has determined that only holders of IPC common stock of record at  the
close of business on July 10, 1996, will be entitled to notice of and to vote at
the meeting.
 
    Approval  of proposals  1 and  2 are conditions  to the  consummation of the
transactions contemplated  by  the Merger  Agreement.  As described  in  greater
detail  in the attached Joint Proxy  Statement/ Prospectus, the shares of common
stock issued pursuant  to the  Merger Agreement  are expected  to have  attached
thereto associated rights to purchase common stock.
 
    Under  Section 262 of  the Delaware General Corporation  Law, holders of IPC
preferred stock have the right to dissent from the transactions contemplated  by
the  Merger  Agreement  and, if  such  transactions are  consummated,  to obtain
payment of the "fair value" of their shares. Section 262 of the Delaware General
Corporation Law is attached in full as  Annex Q to the accompanying Joint  Proxy
Statement/Prospectus,  which also includes  the description of  procedures to be
followed under  that section  by a  holder  of IPC  preferred stock  wishing  to
dissent.
<PAGE>
    If  you  do not  expect to  be present  at the  meeting, please  execute the
enclosed proxy and return it promptly in the accompanying addressed envelope.
 
                                          INTERSTATE POWER COMPANY
 
                                          BY: [/S/ J.C. MCGOWAN]
                                             J.C. McGowan
                                              SECRETARY
Dubuque, Iowa
July 23, 1996
 
YOUR VOTE IS IMPORTANT  NO MATTER HOW  LARGE OR SMALL YOUR  HOLDINGS MAY BE.  TO
ASSURE  YOUR  REPRESENTATION AT  THE ANNUAL  MEETING,  PLEASE DATE  THE ENCLOSED
PROXY, WHICH IS SOLICITED BY THE BOARD OF DIRECTORS OF IPC, SIGN EXACTLY AS YOUR
NAME APPEARS THEREON AND RETURN IMMEDIATELY.
<PAGE>
                             JOINT PROXY STATEMENT
                                       OF
                              WPL HOLDINGS, INC.,
                              IES INDUSTRIES INC.
                                      AND
                            INTERSTATE POWER COMPANY
                            (A DELAWARE CORPORATION)
                           --------------------------
 
                                   PROSPECTUS
                                       OF
 
<TABLE>
<S>                                                      <C>        <C>
                  WPL HOLDINGS, INC.
                     TO BE RENAMED
             INTERSTATE ENERGY CORPORATION                                         INTERSTATE POWER COMPANY
               (A WISCONSIN CORPORATION)                    AND                    (A WISCONSIN CORPORATION)
          relating to shares of common stock                                 relating to shares of preferred stock
            (and accompanying common stock
                   purchase rights)
</TABLE>
 
                           --------------------------
 
    This Joint Proxy Statement/Prospectus relates to the proposed combination of
WPL  Holdings, Inc.,  IES Industries  Inc. and  Interstate Power  Company into a
single  entity  to  be  known   after  the  combination  as  Interstate   Energy
Corporation.  Following the combination, the  utility subsidiaries of Interstate
Energy Corporation (Wisconsin Power  and Light Company,  IES Utilities Inc.  and
Interstate  Power Company)  will continue to  operate as  separate entities. Set
forth below are  disclosures relating to  (i) the proposed  mergers and  certain
related  transactions contemplated by the Agreement and Plan of Merger, dated as
of November 10, 1995, as  amended (together with a  related Plan of Merger,  the
"Merger  Agreement"),  by  and  among  WPL  Holdings,  Inc.,  a  holding company
incorporated under the laws of the  State of Wisconsin ("WPLH"), IES  Industries
Inc.,  a  holding company  incorporated  under the  laws  of the  State  of Iowa
("IES"), Interstate  Power Company,  an  operating public  utility  incorporated
under the laws of the State of Delaware ("IPC"), WPLH Acquisition Co., a wholly-
owned  subsidiary of WPLH incorporated under the  laws of the State of Wisconsin
("Acquisition"), and Interstate Power Company, a wholly-owned subsidiary of  IPC
incorporated  under the laws of the State of Wisconsin ("New IPC"), and (ii) the
election of directors and certain other  matters related to the annual  meetings
of  each of WPLH, IES and IPC. The  other matters to be considered at the annual
meetings include: (i) in  the case of WPLH,  the approval of charter  amendments
authorizing  the change in  corporate name to  Interstate Energy Corporation and
increasing the number of authorized shares  of common stock, the appointment  of
independent auditors, and the transaction of any other business properly brought
before  the  meeting; (ii)  in the  case of  IES, the  transaction of  any other
business properly brought before the meeting; and (iii) in the case of IPC,  the
approval  of a charter amendment providing the holders of preferred stock of IPC
with specified voting rights and the transaction of any other business  properly
brought before the meeting.
    Upon  consummation of the mergers provided for in the Merger Agreement, WPLH
(which will be renamed Interstate Energy Corporation ("Interstate Energy") at or
prior to  such time)  will  be the  holding company  of  the utility  and  other
subsidiaries  of WPLH, including Wisconsin Power  and Light Company, a Wisconsin
corporation ("WP&L"), the utility and  other subsidiaries of IES, including  IES
Utilities  Inc.,  an  Iowa  corporation ("Utilities")  (which,  if  required for
regulatory reasons,  will  be  merged  with  and  into  IES  Utilities  Inc.,  a
corporation  which will be  a wholly-owned subsidiary  of IES incorporated under
the laws  of the  State of  Wisconsin  ("New Utilities")),  and IPC  (which,  if
required  for regulatory  reasons, will  be merged  with and  into the Wisconsin
corporation, New IPC).  Interstate Energy  will be a  registered public  utility
holding company under the Public Utility Holding Company Act of 1935, as amended
(the  "1935  Act").  See  "Regulatory  Matters." As  used  in  this  Joint Proxy
Statement/Prospectus, "Interstate Energy" shall refer to WPLH from and after the
effective time of the mergers provided for in the Merger Agreement.
    Subject to an  alternative structure described  below, the Merger  Agreement
provides for: (i) the merger of IES with and into WPLH, which merger will result
in  the combination  of WPLH  and IES  as a  single company  (the "IES Merger"),
pursuant to which each outstanding share of  common stock, no par value, of  IES
("IES  Common Stock")  (other than  shares held  by IES  shareowners who perfect
dissenters' rights under  applicable state  law ("IES  Dissenting Shares"),  and
other  than  shares  owned  by WPLH,  IES  or  IPC or  any  of  their respective
subsidiaries, which shares will be cancelled)  will be converted into the  right
to  receive 1.01 shares  (the "IES Ratio")  of common stock,  par value $.01 per
share, of Interstate  Energy ("Interstate  Energy Common Stock");  and (ii)  the
merger  of  Acquisition with  and  into IPC,  which  merger will  result  in IPC
becoming a subsidiary of Interstate  Energy (the "IPC Direct Merger"),  pursuant
to  which (a) each outstanding share of common stock, par value $3.50 per share,
of IPC ("IPC Common Stock") (other than shares owned by WPLH, IES or IPC or  any
of  their  respective  subsidiaries, which  shares  will be  cancelled)  will be
converted into the right to receive  1.11 shares (the "IPC Ratio," and  together
with the IES Ratio, the "Ratios") of Interstate Energy Common Stock and (b) each
outstanding  share of  preferred stock,  par value $50  per share,  of IPC ("IPC
Preferred Stock")  (other than  shares held  by IPC  preferred stockholders  who
perfect dissenters' rights under applicable state law ("IPC Dissenting Shares"))
will  remain outstanding and shall be  unchanged thereby (including with respect
to the  additional voting  rights proposed  to  be approved  at the  IPC  annual
meeting).  Unless regulatory requirements require  the foregoing transactions to
be consummated  pursuant  to  the  alternate  structure  described  below,  such
transactions will be effected in the manner described above.
 
                [COVER PAGE IS CONTINUED ON THE FOLLOWING PAGE]
                           --------------------------
 
THESE  SECURITIES HAVE  NOT BEEN APPROVED  OR DISAPPROVED BY  THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE  SECURITIES COMMISSION NOR HAS THE  COMMISSION
 OR  ANY STATE SECURITIES COMMISSION PASSED  UPON THE ACCURACY OR ADEQUACY OF
   THIS JOINT  PROXY      STATEMENT/PROSPECTUS.  ANY REPRESENTATION  TO  THE
                        CONTRARY IS A CRIMINAL OFFENSE.
                           --------------------------
 
    This  Joint Proxy Statement/Prospectus  and accompanying forms  of proxy are
first being mailed  to shareowners of  WPLH, IES and  IPC on or  about July  23,
1996.
 
      THE DATE OF THIS JOINT PROXY STATEMENT/PROSPECTUS IS JULY 11, 1996.
<PAGE>
    The  Merger Agreement provides, however, that  if, prior to the consummation
of the  transactions  described  above, the  companies  determine  that  certain
regulatory  requirements  mandate that  the  utility subsidiaries  of Interstate
Energy be  Wisconsin corporations,  the transactions  will be  consummated in  a
manner  designed to comply with such regulatory requirements. In that event, the
(i) IES Merger will be  effected as described above  and (ii) Utilities will  be
merged  with and  into New  Utilities (the  "Utilities Reincorporation Merger"),
pursuant to which each  outstanding share of common  stock, $2.50 par value,  of
Utilities  ("Utilities Common Stock") will be converted into one share of common
stock, $2.50 par value, of New Utilities ("New Utilities Common Stock"). If  the
Utilities   Reincorporation  Merger  is  to  be  consummated,  it  is  currently
anticipated that the  shares of cumulative  preferred stock, $50  par value,  of
Utilities  ("Utilities Preferred  Stock") then  outstanding will  be redeemed by
Utilities prior to the consummation of such merger. Redemption of the  Utilities
Preferred   Stock  is  not  expected  to  occur  as  part  of  the  transactions
contemplated hereby if the Utilities  Reincorporation Merger is not required  to
be  effected.  If  the Utilities  Reincorporation  Merger is  not  effected, the
Utilities Preferred Stock will remain outstanding  and unchanged as a result  of
the transactions described herein. See "Summary -- The Parties -- IES," "Summary
- -- The Mergers" and "The Mergers -- Redemption of Utilities Preferred Stock." In
addition, the merger involving IPC will be reconstituted to provide for: (i) the
merger  of IPC with and into New IPC (the "IPC Reincorporation Merger") pursuant
to which (a) each outstanding share of IPC Common Stock (other than shares owned
by WPLH, IES or IPC or any  of their respective subsidiaries, which shares  will
be  cancelled) will be converted into one share of common stock, par value $3.50
per share, of New IPC ("New IPC Common Stock") and (b) each outstanding share of
IPC Preferred Stock (other  than IPC Dissenting Shares)  will be converted  into
one  share of  preferred stock, par  value $50 per  share, of New  IPC ("New IPC
Preferred Stock") with terms (including  dividend rates) and designations  under
New   IPC's  Restated  Articles   of  Incorporation  (the   "New  IPC  Charter")
substantially identical to those of  IPC's Preferred Stock under IPC's  Restated
Certificate  of  Incorporation  (the "IPC  Charter"),  including  the additional
voting rights proposed to be  approved at the IPC  annual meeting; and (ii)  the
merger of Acquisition with and into New IPC, which merger will result in New IPC
becoming a subsidiary of Interstate Energy (the "IPC Merger"), pursuant to which
(a)  each outstanding share of New IPC  Common Stock (other than shares owned by
WPLH, IES  or  IPC  or any  of  their  respective subsidiaries,  which  will  be
cancelled)  will be  converted into  the right  to receive  shares of Interstate
Energy Common Stock based on the IPC Ratio and (b) each outstanding share of New
IPC Preferred Stock (other than  IPC Dissenting Shares) will remain  outstanding
and unchanged as a result thereof.
    APPROVAL OF THE MERGER AGREEMENT AT THE ANNUAL MEETINGS OF EACH OF WPLH, IES
AND  IPC WILL CONSTITUTE APPROVAL OF THE TRANSACTIONS DESCRIBED ABOVE REGARDLESS
OF WHICH OF THE ALTERNATIVE  STRUCTURES DESCRIBED HEREIN IS ULTIMATELY  EMPLOYED
TO EFFECT SUCH TRANSACTIONS. The IES Merger and the IPC Direct Merger or, in the
alternative,  the IES Merger, the IPC Reincorporation Merger, the IPC Merger and
the Utilities Reincorporation Merger, are collectively referred to herein as the
"Mergers." Approval  of the  holders of  IES Common  Stock is  not  specifically
required  to consummate the Utilities Reincorporation  Merger. In the event that
the Utilities Reincorporation  Merger is  required and  the Utilities  Preferred
Stock  is therefore  redeemed, IES, as  the sole shareholder  of Utilities, will
approve the  Utilities  Reincorporation Merger.  The  Utilities  Reincorporation
Merger will not, however, be effected if the holders of IES Common Stock fail to
approve the Merger Agreement. The approval of the holders of IPC Common Stock is
required  to approve the IPC Reincorporation Merger, if, for regulatory reasons,
such transaction is required in order to consummate the Mergers. Approval of the
holders  of  IPC   Preferred  Stock  is   not  required  to   approve  the   IPC
Reincorporation Merger.
    The  Merger Agreement requires that specified termination fees be paid under
certain circumstances in the event the Merger Agreement is terminated, including
if there is  a material, willful  breach of  the Merger Agreement  or if,  under
certain  circumstances, a business combination with a third party is consummated
within two and one-half  years of the termination  of the Merger Agreement.  The
aggregate  termination  fees  under  this provision  together  with  the amounts
payable under certain provisions of stock option agreements entered into by  the
parties  may  not  exceed  $40,000,000  payable by  each  of  WPLH  and  IES and
$20,000,000 payable by IPC. The Merger  Agreement also provides for the  payment
of expenses by a breaching party in the event the Merger Agreement is terminated
as  a result of a breach of  the representations and warranties or covenants and
agreements contained in  the Merger  Agreement. In  the event  of a  non-willful
breach,  each non-breaching party  will be entitled to  the reimbursement of its
documented  out-of-pocket   expenses,  not   to  exceed   $5,000,000  for   each
non-breaching  party. In the  event the breach is  willful, the $5,000,000 limit
will not apply. For a more detailed description of the termination fees that may
be payable in certain  circumstances, see "The  Merger Agreement --  Termination
Fees"  and  "The  Stock  Option  Agreements  --  Certain  Repurchases  and Other
Payments."
    Under applicable state law,  holders of IES Common  Stock and IPC  Preferred
Stock  who  do not  wish  to accept  the  consideration to  be  paid to  them in
connection with the Mergers will have the right to have the fair value of  their
shares appraised by judicial determination and paid to them. In order to perfect
such  dissenters' rights,  holders of IES  Common Stock and  IPC Preferred Stock
must comply with the procedural requirements of applicable state law, including,
without limitation, delivering notice to  IES or IPC, as  the case may be,  with
respect  to the exercise of  such rights prior to the  annual meetings of IES or
IPC, as the case may be, and not voting in favor of the Merger Agreement. For  a
discussion  of the  dissenters' rights applicable  to the holders  of IES Common
Stock, see "The  Mergers --  Iowa Dissenters'  Rights" and  Annex P,  and for  a
discussion  of the dissenters' rights applicable to the holders of IPC Preferred
Stock, see "The Mergers -- Delaware Dissenters' Rights" and Annex Q. Holders  of
WPLH Common Stock and IPC Common Stock are not entitled to dissenters' rights in
connection with the Mergers.
    In  connection with the Mergers, each outstanding share of common stock, par
value $.01 per share, of WPLH ("WPLH Common Stock") will remain outstanding  and
unchanged  as  one  share  of  Interstate  Energy  Common  Stock.  Based  on the
capitalization of WPLH, IES and IPC on July 10, 1996 and the Ratios, holders  of
WPLH  Common  Stock, IES  Common  Stock and  IPC  Common Stock  would  have held
approximately 43%, 42.2%  and 14.8%,  respectively, of the  aggregate number  of
shares of Interstate Energy Common Stock that would have been outstanding if the
Mergers   had  been   consummated  as  of   such  date.  In   this  Joint  Proxy
Statement/Prospectus, unless the context  otherwise requires, all references  to
Interstate  Energy Common Stock include, if applicable, the associated rights to
purchase shares  of  such common  stock  pursuant to  the  terms of  the  Rights
Agreement  between WPLH and Morgan Shareholder Services Trust Company, as Rights
Agent thereunder, dated as  of February 22, 1989  (the "Rights Agreement").  For
more  detailed description  of the  Rights Agreement  and the  associated rights
accompanying shares  of  Interstate Energy  Common  Stock, see  "Description  of
Interstate Energy Capital Stock -- Certain Anti-Takeover Provisions."
<PAGE>
    This  Joint Proxy Statement/Prospectus constitutes  a prospectus of WPLH (to
be renamed Interstate Energy) filed as part of the Joint Registration  Statement
(as  hereinafter defined) with respect to  up to 42,798,875 shares of Interstate
Energy Common Stock to be  issued pursuant to or  as contemplated by the  Merger
Agreement.  This Joint Proxy Statement/Prospectus  also constitutes a prospectus
of New IPC filed as part of the Joint Registration Statement with respect to  up
to 761,381 shares of New IPC Preferred Stock to be issued, assuming that the IPC
Reincorporation Merger is effected, pursuant to or as contemplated by the Merger
Agreement.
 
    This  Joint Proxy Statement/Prospectus is being  furnished to the holders of
WPLH Common Stock  in connection with  solicitation of proxies  by the Board  of
Directors of WPLH (the "WPLH Board") for use at the annual meeting of WPLH to be
held  immediately following the  annual meeting of shareowners  of WP&L at 10:00
a.m., Central Time, on Thursday, September 5, 1996 at the Exhibition Hall of the
Dane County  Expo  Center,  1881  Expo Mall,  Madison,  Wisconsin,  and  at  any
adjournment  or postponement thereof (the "WPLH  Meeting"). At the WPLH Meeting,
in addition to  voting upon proposals  to approve the  Merger Agreement and  the
transactions   contemplated  thereby,  including  the   issuance  of  shares  of
Interstate Energy Common Stock  pursuant to the terms  of the Merger  Agreement,
and  to approve certain amendments to  the Restated Articles of Incorporation of
WPLH (the "WPLH Charter"), holders of  WPLH Common Stock will also consider  and
vote  upon  proposals  with  respect  to  the  election  of  directors  and  the
ratification of the appointment of WPLH's independent auditors. Information with
respect to these proposals is  being furnished at the  back of this Joint  Proxy
Statement/Prospectus to the shareowners of WPLH only.
 
    This Joint Proxy Statement/Prospectus is also being furnished to the holders
of  IES Common Stock in connection with the solicitation of proxies by the Board
of Directors of IES (the "IES Board") for use at the annual meeting of IES to be
held at 10:00 a.m., Central Time, on Thursday, September 5, 1996 at the  Collins
Plaza  Hotel, 1200 Collins Road N.E., Cedar Rapids, Iowa, and at any adjournment
or postponement thereof (the "IES Meeting"). At the IES Meeting, in addition  to
voting  upon a proposal to  approve the Merger Agreement,  holders of IES Common
Stock will also consider and vote upon  a proposal with respect to the  election
of  directors. Information with  respect to this proposal  is being furnished at
the back of  this Joint Proxy  Statement/Prospectus to the  shareholders of  IES
only.
 
    This Joint Proxy Statement/Prospectus is also being furnished to the holders
of  IPC Common Stock in connection with the solicitation of proxies by the Board
of Directors of IPC (the "IPC Board") for use at the annual meeting of IPC to be
held at 10:00 a.m., Central Time, on Thursday, September 5, 1996 at the  Holiday
Inn  Dubuque Five Flags, 450 Main Street,  Dubuque, Iowa, and at any adjournment
or postponement thereof (the "IPC Meeting"). At the IPC Meeting, in addition  to
voting upon a proposal to approve the Merger Agreement and a proposal to approve
an  amendment to the IPC Charter to provide expanded voting rights to holders of
shares of IPC Preferred  Stock, holders of IPC  Common Stock will also  consider
and  vote upon a proposal with respect to the election of directors. Information
with respect to the proposal to elect directors of IPC is being furnished at the
back of this Joint Proxy Statement/Prospectus to the stockholders of IPC only.
 
    All information concerning WPLH and Acquisition included in this Joint Proxy
Statement/ Prospectus has  been furnished  by WPLH,  all information  concerning
IES,    Utilities   and   New   Utilities   included   in   this   Joint   Proxy
Statement/Prospectus has been  furnished by IES  and all information  concerning
IPC  and  New IPC  included in  this Joint  Proxy Statement/Prospectus  has been
furnished by IPC.
 
    No  person  is  authorized   to  give  any  information   or  to  make   any
representation  other than those contained or  incorporated by reference in this
Joint Proxy Statement/Prospectus,  and, if  given or made,  such information  or
representation  should not be relied upon  as having been authorized. This Joint
Proxy  Statement/Prospectus  does  not  constitute  an  offer  to  sell,  or   a
solicitation of an offer to purchase, the securities offered by this Joint Proxy
Statement/Prospectus, or the solicitation of a proxy, in any jurisdiction, to or
from  any person  to whom or  from whom  it is unlawful  to make  such an offer,
solicitation of an offer or proxy solicitation in such jurisdiction. Neither the
delivery of  this  Joint  Proxy Statement/Prospectus  nor  any  distribution  of
securities  pursuant to this  Joint Proxy Statement/Prospectus  shall, under any
circumstances, create  an implication  that  there has  been  no change  in  the
affairs  of WPLH, IES  or IPC or in  the information set  forth herein since the
date of this Joint Proxy Statement/Prospectus.
 
                                       ii
<PAGE>
    This Joint  Proxy Statement/Prospectus  does  not cover  any resale  of  the
securities  to be received by shareowners of IES or IPC upon consummation of the
Mergers, and  no person  is  authorized to  make any  use  of this  Joint  Proxy
Statement/Prospectus in connection with any such resale.
 
                             AVAILABLE INFORMATION
 
    WPLH,  IES  and IPC  are subject  to the  informational requirements  of the
Securities Exchange  Act  of 1934,  as  amended  (the "Exchange  Act"),  and  in
accordance  therewith, file reports, proxy statements and other information with
the  Securities  and  Exchange  Commission  (the  "SEC").  Such  reports,  proxy
statements  and other information filed by WPLH, IES and IPC with the SEC can be
inspected and copied at the public reference facilities maintained by the SEC at
Room 1024, Judiciary Plaza, 450 Fifth  Street, N.W., Washington, D.C. 20549  and
at  the Regional Offices of the SEC at Citicorp Center, 500 West Madison Street,
Suite 1400, Chicago,  Illinois 60661-2511, and  at 7 World  Trade Center,  Suite
1300,  New York, New  York 10048. Copies  of such material  may also be obtained
from the Public Reference Section of the SEC, Judiciary Plaza, 450 Fifth Street,
N.W., Washington,  D.C. 20549  at  prescribed rates.  In addition,  WPLH  Common
Stock,  IES Common Stock and  IPC Common Stock are listed  on the New York Stock
Exchange, the Chicago Stock  Exchange and the Pacific  Stock Exchange, and  WPLH
Common  Stock and IES Common Stock are  listed on the Boston Stock Exchange, and
reports, proxy statements and  other information filed by  WPLH, IES and/or  IPC
with  such  exchanges may  be inspected  at the  offices of  the New  York Stock
Exchange, Inc. (the  "NYSE"), 20  Broad Street, 7th  Floor, New  York, New  York
10005,  the Boston Stock  Exchange, Inc. (the "BSE"),  One Boston Place, Boston,
Massachusetts 02108, the  Chicago Stock  Exchange, Inc. (the  "CSE"), 440  South
LaSalle  Street, Chicago,  Illinois 60605, or  the Pacific  Stock Exchange, Inc.
(the "PSE"), 301 Pine Street, San Francisco, California 94104, and such material
and other information concerning IES can  also be inspected at the  Philadelphia
Stock   Exchange,  Inc.   (the  "PhSE"),   1900  Market   Street,  Philadelphia,
Pennsylvania 19103, on which exchange the IES Common Stock is listed.
 
    In addition, the SEC maintains a  Web site that contains reports, proxy  and
information  statements and  other information  regarding registrants  that file
electronically with the SEC. The address of such Web site is http://www.sec.gov.
 
    WPLH and New IPC have filed with  the SEC a Joint Registration Statement  on
Form  S-4 (together  with all  amendments, schedules  and exhibits  thereto, the
"Joint Registration Statement")  under the  Securities Act of  1933, as  amended
(the  "Securities Act"), with respect to  the shares of Interstate Energy Common
Stock to be issued in connection with the  IES Merger and the IPC Merger or  IPC
Direct  Merger, as the  case may be, and  the shares of  New IPC Preferred Stock
which may be  issued in  connection with  the IPC  Reincorporation Merger.  This
Joint  Proxy Statement/Prospectus does not contain all the information set forth
in the Joint Registration Statement, certain parts of which have been omitted in
accordance with the  rules and regulations  of the SEC.  The Joint  Registration
Statement is available for inspection and copying as set forth above. Statements
contained   in  this  Joint  Proxy   Statement/Prospectus  or  in  any  document
incorporated by reference  in this  Joint Proxy Statement/Prospectus  as to  the
contents of any contract or other document referred to herein or therein are not
necessarily  complete, and, in each  instance, reference is made  to the copy of
such contract or other  document filed as an  exhibit to the Joint  Registration
Statement  or such  other document, each  such statement being  qualified in all
respects by such reference.
 
                    INCORPORATION OF DOCUMENTS BY REFERENCE
 
    THIS JOINT PROXY  STATEMENT/PROSPECTUS INCORPORATES  DOCUMENTS BY  REFERENCE
WHICH ARE NOT PRESENTED HEREIN OR DELIVERED HEREWITH. SUCH DOCUMENTS (OTHER THAN
EXHIBITS TO SUCH DOCUMENTS UNLESS SUCH EXHIBITS ARE SPECIFICALLY INCORPORATED BY
REFERENCE)  ARE AVAILABLE TO ANY PERSON, INCLUDING ANY BENEFICIAL OWNER, TO WHOM
THIS JOINT  PROXY  STATEMENT/PROSPECTUS  IS  DELIVERED,  UPON  WRITTEN  OR  ORAL
REQUEST,  WITHOUT CHARGE, IN THE CASE OF DOCUMENTS RELATING TO WPLH, DIRECTED TO
EDWARD M.  GLEASON,  VICE  PRESIDENT, TREASURER  AND  CORPORATE  SECRETARY,  WPL
HOLDINGS,  INC., 222 WEST  WASHINGTON AVENUE, P.O.  BOX 2568, MADISON, WISCONSIN
53701-2568 (TELEPHONE NUMBER (608) 252-3311), IN THE CASE OF DOCUMENTS  RELATING
TO  IES, DIRECTED TO STEPHEN W. SOUTHWICK, ESQ., VICE PRESIDENT, GENERAL COUNSEL
& SECRETARY,  IES INDUSTRIES  INC.,  IES TOWER,  200  FIRST STREET  S.E.,  CEDAR
RAPIDS,  IOWA  52401  (TELEPHONE  NUMBER  (319) 398-4411),  OR  IN  THE  CASE OF
 
                                      iii
<PAGE>
DOCUMENTS RELATING  TO  IPC,  DIRECTED  TO  JOSEPH  C.  MCGOWAN,  SECRETARY  AND
TREASURER,  INTERSTATE POWER COMPANY,  1000 MAIN STREET,  P.O. BOX 769, DUBUQUE,
IOWA 52004-0769 (TELEPHONE  NUMBER (319)  582-5421). IN ORDER  TO ENSURE  TIMELY
DELIVERY OF THE DOCUMENTS, ANY REQUESTS SHOULD BE MADE BY AUGUST 28, 1996.
 
    The  following documents filed with  the SEC by WPLH  (File No. 1-9894), IES
(File No. 1-9187)  or IPC (File  No. 1-3632)  pursuant to the  Exchange Act  are
incorporated in this Joint Proxy Statement/ Prospectus by reference:
 
        1.   WPLH's Annual Report  on Form 10-K for  the year ended December 31,
    1995, as amended by the Form 10-K/A filed on April 29, 1996.
 
        2.  WPLH's Quarterly Report on Form 10-Q for the quarter ended March 31,
    1996.
 
        3.  WPLH's  Current Reports on  Form 8-K  dated January 17  and May  22,
    1996.
 
        4.   IES's Annual  Report on Form  10-K for the  year ended December 31,
    1995, as amended by the Form 10-K/A filed on April 29, 1996.
 
        5.  IES's Quarterly Report on Form 10-Q for the quarter ended March  31,
    1996.
 
        6.   IES's Current Reports on Form  8-K dated February 9, April 3, April
    12 and May 22, 1996.
 
        7.   The description  of IES  Common Stock  (including the  accompanying
    preferred  share purchase rights) contained in IES's registration statements
    filed pursuant to Section 12 of the Exchange Act and any amendment or report
    filed for the purpose of updating such description.
 
        8.  IPC's Annual  Report on Form  10-K for the  year ended December  31,
    1995, as amended by the Form 10-K/A filed on April 29, 1996.
 
        9.   IPC's Quarterly Report on Form 10-Q for the quarter ended March 31,
    1996.
 
        10. IPC's Current Report on Form 8-K dated May 22, 1996.
 
        11. The description of IPC Common Stock contained in IPC's  registration
    statements  filed  pursuant  to  Section  12 of  the  Exchange  Act  and any
    amendment or report filed for the purpose of updating such description.
 
    In lieu of incorporating by reference  the description of WPLH Common  Stock
(including  the accompanying common  stock purchase rights)  contained in WPLH's
Form 8-B and Form  8-A registration statements filed  pursuant to Section 12  of
the   Exchange  Act,   such  description  is   included  in   this  Joint  Proxy
Statement/Prospectus. See "Description of Interstate Energy Capital Stock."
 
    The information relating to WPLH, IES and IPC contained in this Joint  Proxy
Statement/  Prospectus does not  purport to be comprehensive  and should be read
together with the information in the documents incorporated by reference herein.
 
    All documents filed by WPLH, IES  or IPC pursuant to Sections 13(a),  13(c),
14  or 15(d) of the Exchange Act subsequent  to the date hereof and prior to the
date of the WPLH Meeting on Thursday, September 5, 1996, and any adjournment  or
postponement  thereof, the IES  Meeting on Thursday, September  5, 1996, and any
adjournment or postponement thereof, or  the IPC Meeting on Thursday,  September
5,  1996, and  any adjournment or  postponement thereof,  respectively, shall be
deemed   to   be   incorporated   by    reference   into   this   Joint    Proxy
Statement/Prospectus  and to be  a part hereof  from the date  of filing of such
documents.
 
    Any statement contained in  a document incorporated  by reference herein  or
deemed  to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this  Joint Proxy Statement/Prospectus to the  extent
that  a statement contained  herein or in any  other subsequently filed document
which also is or is  deemed to be incorporated  by reference herein modifies  or
supersedes  such statement. Any statement so modified or superseded shall not be
deemed, except as so modified or superseded, to constitute a part of this  Joint
Proxy Statement/Prospectus.
 
                                       iv
<PAGE>
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                             ---------
<S>                                                                                                          <C>
AVAILABLE INFORMATION......................................................................................        iii
INCORPORATION OF DOCUMENTS BY REFERENCE....................................................................        iii
INDEX OF DEFINED TERMS.....................................................................................         ix
SUMMARY....................................................................................................          1
  The Parties..............................................................................................          1
  The Meetings.............................................................................................          2
  Required Vote............................................................................................          4
  The Mergers..............................................................................................          4
  Exchange of Stock Certificates...........................................................................          6
  Stock Option Agreements..................................................................................          6
  Treatment of Shares; Ratios..............................................................................          7
  Background...............................................................................................          8
  Reasons for the Mergers..................................................................................          8
  Recommendations of the Board of Directors................................................................          8
  Opinions of Financial Advisors...........................................................................          9
  Interests of Certain Persons in the Mergers..............................................................          9
  Management of Interstate Energy..........................................................................         11
  Conditions to the Mergers................................................................................         11
  Rights to Terminate, Amend or Waive Conditions...........................................................         11
  Certain Federal Income Tax Consequences..................................................................         12
  Operations After the Mergers.............................................................................         13
  Regulatory Matters.......................................................................................         13
  Accounting Treatment.....................................................................................         14
  Dissenters' Rights.......................................................................................         15
  Dividends................................................................................................         15
  Amendments to WPLH Charter...............................................................................         16
  Amendment to IPC Charter.................................................................................         16
  Comparison of Rights of Shareowners......................................................................         16
SELECTED HISTORICAL AND PRO FORMA DATA.....................................................................         17
  Selected Historical Financial and Market Data............................................................         17
  Selected Unaudited Pro Forma Financial Data..............................................................         21
  Comparative Book Values, Dividends and Earnings Per Common Share.........................................         22
  Comparative Market Prices and Dividends..................................................................         24
MEETINGS, VOTING AND PROXIES...............................................................................         26
  The WPLH Meeting.........................................................................................         26
  The IES Meeting..........................................................................................         28
  The IPC Meeting..........................................................................................         30
THE MERGERS................................................................................................         31
  Background of the Mergers................................................................................         31
  Reasons for the Mergers; Recommendations of the Boards of Directors......................................         46
  Opinions of Financial Advisors...........................................................................         53
  Interests of Certain Persons in the Mergers..............................................................         69
  Certain Arrangements Regarding the Directors and Management of Interstate Energy Following the Mergers...         72
  Employment Agreements....................................................................................         73
  Certain Federal Income Tax Consequences..................................................................         74
  Accounting Treatment.....................................................................................         77
  Stock Exchange Listing of Interstate Energy Common Stock.................................................         77
</TABLE>
 
                                       v
<PAGE>
<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                             ---------
<S>                                                                                                          <C>
  Redemption of Utilities Preferred Stock..................................................................         77
  Federal Securities Law Consequences......................................................................         77
  No Wisconsin Dissenters' Rights..........................................................................         78
  Iowa Dissenters' Rights..................................................................................         78
  Delaware Dissenters' Rights..............................................................................         80
REGULATORY MATTERS.........................................................................................         82
  State Approvals and Related Matters......................................................................         82
  Public Utility Holding Company Act of 1935...............................................................         84
  Federal Power Act........................................................................................         85
  Antitrust Considerations.................................................................................         86
  Atomic Energy Act........................................................................................         86
  Other....................................................................................................         86
  General..................................................................................................         87
THE MERGER AGREEMENT.......................................................................................         87
  The Mergers..............................................................................................         87
  Subsidiaries and Joint Ventures..........................................................................         90
  Representations and Warranties...........................................................................         90
  Certain Covenants........................................................................................         91
  No Solicitation of Transactions..........................................................................         92
  Interstate Energy Board of Directors.....................................................................         93
  Indemnification..........................................................................................         93
  Conditions to Each Party's Obligation to Effect the Mergers..............................................         94
  Benefit Plans............................................................................................         95
  Termination..............................................................................................         96
  Termination Fees.........................................................................................         97
  Expenses.................................................................................................         98
  Amendment and Waiver.....................................................................................         98
  Standstill Provisions....................................................................................         99
THE STOCK OPTION AGREEMENTS................................................................................         99
  General..................................................................................................         99
  Certain Repurchases and Other Payments...................................................................        100
  Voting...................................................................................................        101
  Restrictions on Transfer.................................................................................        101
AMENDMENTS TO WPLH RESTATED ARTICLES OF INCORPORATION......................................................        101
  Name Change Amendment....................................................................................        102
  Common Stock Amendment...................................................................................        102
AMENDMENT TO IPC RESTATED CERTIFICATE OF INCORPORATION.....................................................        103
DESCRIPTION OF INTERSTATE ENERGY CAPITAL STOCK.............................................................        104
  General..................................................................................................        104
  Interstate Energy Common Stock...........................................................................        104
  Certain Anti-Takeover Provisions.........................................................................        105
DESCRIPTION OF NEW IPC PREFERRED STOCK.....................................................................        107
  General..................................................................................................        107
  Dividend Rights..........................................................................................        107
  Dividend Restrictions....................................................................................        108
  Voting Rights............................................................................................        108
  Redemption Provisions....................................................................................        109
  Change in Control........................................................................................        109
  Liquidation Rights.......................................................................................        109
</TABLE>
 
                                       vi
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                             ---------
<S>                                                                                                          <C>
 Preemption and Subscription Rights........................................................................        110
COMPARISON OF SHAREOWNER RIGHTS............................................................................        110
  Comparison of Interstate Energy Charter and Bylaws to IES and IPC Charter and Bylaws.....................        110
  Comparison of Wisconsin, Iowa and Delaware Law...........................................................        114
  Anti-Takeover Statutes...................................................................................        118
UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION.........................................................        120
SELECTED INFORMATION CONCERNING WPLH, IES AND IPC..........................................................        132
  Business of WPLH.........................................................................................        132
  Business of IES..........................................................................................        132
  Business of IPC..........................................................................................        132
  Certain Business Relationships Between WPLH, IES and IPC.................................................        133
INTERSTATE ENERGY FOLLOWING THE MERGERS....................................................................        133
  Management of Interstate Energy..........................................................................        133
  Operations...............................................................................................        133
  Dividends................................................................................................        134
EXPERTS....................................................................................................        134
LEGAL MATTERS..............................................................................................        135
SHAREOWNER PROPOSALS.......................................................................................        135
ELECTION OF WPLH DIRECTORS.................................................................................        136
  Nominees.................................................................................................        136
  Continuing Directors.....................................................................................        137
APPOINTMENT OF INDEPENDENT AUDITORS........................................................................        139
MEETINGS AND COMMITTEES OF THE WPLH BOARD..................................................................        139
  Audit Committee..........................................................................................        140
  Compensation and Personnel Committee.....................................................................        140
  Nominating Committee.....................................................................................        140
  Compensation of Directors................................................................................        140
OWNERSHIP OF VOTING SECURITIES.............................................................................        141
COMPENSATION OF EXECUTIVE OFFICERS.........................................................................        142
  Stock Options............................................................................................        143
  Long-Term Incentive Awards...............................................................................        144
  Certain Transactions and Agreements with Executives......................................................        145
  Retirement and Employee Benefit Plans....................................................................        145
  Report of the Compensation and Personnel Committee on Executive Compensation.............................        147
COMPARISON OF FIVE-YEAR CUMULATIVE TOTAL RETURN............................................................        151
COMPLIANCE WITH SECTION 16(a) OF THE SECURITIES EXCHANGE ACT OF 1934.......................................        151
</TABLE>
 
                                      vii
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                             ---------
<S>                                                                                                          <C>
 Preemption and Subscription Rights........................................................................        110
COMPARISON OF SHAREOWNER RIGHTS............................................................................        110
  Comparison of Interstate Energy Charter and Bylaws to IES and IPC Charter and Bylaws.....................        110
  Comparison of Wisconsin, Iowa and Delaware Law...........................................................        114
  Anti-Takeover Statutes...................................................................................        118
UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION.........................................................        120
SELECTED INFORMATION CONCERNING WPLH, IES AND IPC..........................................................        132
  Business of WPLH.........................................................................................        132
  Business of IES..........................................................................................        132
  Business of IPC..........................................................................................        132
  Certain Business Relationships Between WPLH, IES and IPC.................................................        133
INTERSTATE ENERGY FOLLOWING THE MERGERS....................................................................        133
  Management of Interstate Energy..........................................................................        133
  Operations...............................................................................................        133
  Dividends................................................................................................        134
EXPERTS....................................................................................................        134
LEGAL MATTERS..............................................................................................        135
SHAREOWNER PROPOSALS.......................................................................................        135
ELECTION OF IES DIRECTORS..................................................................................        136
SECURITY OWNERSHIP OF BENEFICIAL OWNERS....................................................................        139
SECURITY OWNERSHIP OF MANAGEMENT...........................................................................        139
OTHER TRANSACTIONS.........................................................................................        140
FUNCTIONING OF THE IES BOARD AND COMMITTEES................................................................        140
COMPENSATION OF DIRECTORS..................................................................................        140
REPORT OF THE COMPENSATION COMMITTEE ON EXECUTIVE COMPENSATION.............................................        141
  Compensation Philosophy..................................................................................        141
  Description of Compensation Programs.....................................................................        142
EXECUTIVE COMPENSATION.....................................................................................        145
PERFORMANCE GRAPH..........................................................................................        147
IES PLANS..................................................................................................        148
IOWA SOUTHERN UTILITIES PLANS..............................................................................        151
EMPLOYMENT AGREEMENT.......................................................................................        152
CERTAIN SEC FILINGS........................................................................................        153
INDEPENDENT PUBLIC ACCOUNTANTS.............................................................................        153
GENERAL....................................................................................................        153
</TABLE>
 
                                      vii
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                             ---------
<S>                                                                                                          <C>
  Preemption and Subscription Rights.......................................................................        110
COMPARISON OF SHAREOWNER RIGHTS............................................................................        110
  Comparison of Interstate Energy Charter and Bylaws to IES and IPC Charter and Bylaws.....................        110
  Comparison of Wisconsin, Iowa and Delaware Law...........................................................        114
  Anti-Takeover Statutes...................................................................................        118
UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION.........................................................        120
SELECTED INFORMATION CONCERNING WPLH, IES AND IPC..........................................................        132
  Business of WPLH.........................................................................................        132
  Business of IES..........................................................................................        132
  Business of IPC..........................................................................................        132
  Certain Business Relationships Between WPLH, IES and IPC.................................................        133
INTERSTATE ENERGY FOLLOWING THE MERGERS....................................................................        133
  Management of Interstate Energy..........................................................................        133
  Operations...............................................................................................        133
  Dividends................................................................................................        134
EXPERTS....................................................................................................        134
LEGAL MATTERS..............................................................................................        135
SHAREOWNER PROPOSALS.......................................................................................        135
ELECTION OF IPC DIRECTORS..................................................................................        136
  Nominees for Directors...................................................................................        136
  Committees of the IPC Board..............................................................................        138
  Compensation of Directors................................................................................        139
  Compensation Committee Interlocks and Insider Participation..............................................        139
PRINCIPAL HOLDERS OF VOTING SECURITIES.....................................................................        139
  Security Ownership of Certain Beneficial Owners..........................................................        139
  Security Ownership of Management.........................................................................        139
COMPENSATION OF DIRECTORS AND EXECUTIVE OFFICERS...........................................................        141
  Compensation Committee Report............................................................................        141
  Performance Graph........................................................................................        142
  Cash Compensation........................................................................................        143
  Summary Compensation Table...............................................................................        143
  Compensation Pursuant to Plans...........................................................................        143
  Other Compensation.......................................................................................        144
  Stock Option and Stock Appreciation Right Plans..........................................................        145
  Termination of Employment and Change in Control Arrangements.............................................        145
  Employment Agreements....................................................................................        145
RELATIONSHIP WITH INDEPENDENT PUBLIC AUDITORS..............................................................        145
</TABLE>
 
                                      vii
<PAGE>
 
<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                            ---------
<S>          <C>                                                                                            <C>
Annex A      Agreement and Plan of Merger, as amended.....................................................        A-1
Annex B      WPLH/IES Stock Option Agreement..............................................................        B-1
Annex C      WPLH/IPC Stock Option Agreement..............................................................        C-1
Annex D      IES/WPLH Stock Option Agreement..............................................................        D-1
Annex E      IES/IPC Stock Option Agreement...............................................................        E-1
Annex F      IPC/WPLH Stock Option Agreement..............................................................        F-1
Annex G      IPC/IES Stock Option Agreement...............................................................        G-1
Annex H      Form of Employment Agreement with Lee Liu....................................................        H-1
Annex I      Form of Employment Agreement with Erroll B. Davis, Jr........................................        I-1
Annex J      Form of Employment Agreement with Wayne Stoppelmoor..........................................        J-1
Annex K      Form of Employment Agreement with Michael Chase..............................................        K-1
Annex L      Opinion of Merrill Lynch, Pierce, Fenner & Smith Incorporated................................        L-1
Annex M      Opinion of Morgan Stanley & Co. Incorporated.................................................        M-1
Annex N      Opinion of Salomon Brothers Inc..............................................................        N-1
Annex O      Proposed Amendments to the Restated Articles of Incorporation of Interstate Energy
              Corporation.................................................................................        O-1
Annex P      Sections 490.1301 to 490.1331 of the Iowa Business Corporation Act...........................        P-1
Annex Q      Section 262 of the Delaware General Corporation Law..........................................        Q-1
Annex R      Proposed Amendment to the Restated Certificate of Incorporation of Interstate Power Company
              (IPC).......................................................................................        R-1
Annex S      Audited Financial Statements of Interstate Power Company (New IPC)...........................        S-1
</TABLE>
 
                                      viii
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
                             INDEX OF DEFINED TERMS
<TABLE>
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
1935 Act.......................................          i
1992 Act.......................................         31
1995 EPS Ratio.................................         55
1996 EPS Ratio.................................         55
Acquisition....................................          i
Antitrust Division.............................         86
Atomic Energy Act..............................         13
Book Value Multiple............................         57
BSE............................................        iii
Business Combination...........................         96
Certificates...................................          6
Class I........................................         93
Class II.......................................         93
Class III......................................         93
Closing........................................         87
Closing Date...................................         87
Code...........................................         12
Common Equity Ratio............................         55
Common Stock Amendment.........................          2
Comparable Merger Transactions.................         57
Confidentiality Agreement......................         97
Consulting Group...............................         36
CRANDIC........................................         57
CSE............................................        iii
DCF............................................         56
Delaware Business Combination Statute..........        119
Delaware Chancery Court........................         15
DGCL...........................................          4
Diversified....................................          1
Dividend Ratio.................................         55
Division.......................................         85
DRSPP Shares...................................         31
EBIT...........................................         56
EBIT Multiple..................................         57
EBITDA.........................................         57
EBITDA Multiple................................         57
Effective Time.................................          5
EHC............................................         56
Electric Utility MOE Transactions..............         62
Employment Agreements..........................         10
EPS............................................         55
ERISA..........................................         91
EWGs...........................................         31
Exchange Act...................................        iii
Exchange Agent.................................         89
FERC...........................................         13
FERC Application...............................         86
FTC............................................         86
HDC............................................          1
 
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
HDC MIP........................................        148
Historical Period..............................         56
HPI............................................         56
HSR Act........................................         13
IBCA...........................................          4
ICC............................................         13
IEA............................................         57
IES............................................          i
IES Board......................................         ii
IES Bylaws.....................................          4
IES Cancelled Shares...........................         88
IES Charter....................................          4
IES Common Stock...............................          i
IES Dissenting Shares..........................          i
IES Joint Ventures.............................         90
IES Meeting....................................         ii
IES Merger.....................................          i
IES Options....................................         99
IES Preferred Stock............................         15
IES Ratio......................................          i
IES Record Date................................          3
IES Stock Award................................         96
IES Stock Option...............................         95
IES Subsidiaries...............................         90
Indemnified Parties............................         94
Interested Contracts or Transactions...........        114
Interstate Energy..............................          i
Interstate Energy Board........................         10
Interstate Energy Bylaws.......................         16
Interstate Energy Charter......................         16
Interstate Energy Common Stock.................          i
IPC............................................          i
IPC Board......................................         ii
IPC Bonds......................................        108
IPC Bylaws.....................................          4
IPC Cancelled Shares...........................         88
IPC Charter....................................          i
IPC Charter Amendment..........................          3
IPC Common Stock...............................          i
IPC Direct Merger..............................          i
IPC Dissenting Shares..........................          i
IPC DRSPP......................................         31
IPC Executives.................................         71
IPC Joint Ventures.............................         90
IPC Meeting....................................         ii
IPC Merger.....................................          i
IPC Options....................................         99
IPC Preference Stock...........................        107
IPC Preferred Stock............................          i
</TABLE>
 
                                       ix
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
<TABLE>
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
IPC Ratio......................................          i
IPC Record Date................................          3
IPC Reincorporation Effective Time.............          5
IPC Reincorporation Merger.....................          i
IPC Severance Agreements.......................         71
IPC Subsidiaries...............................         90
IUB............................................         13
Joint Registration Statement...................        iii
LTM............................................         57
Market/Offer Price.............................        100
Merger Agreement...............................          i
Mergers........................................          i
Merrill Lynch..................................          9
Merrill Lynch Opinion..........................         53
McLeod.........................................          5
McLeod Contingency.............................          5
Minnesota Commission...........................         13
ML IES Comparables.............................         55
ML IPC Comparables.............................         55
ML WPLH Comparables............................         55
Morgan Stanley.................................          9
Mr. Ahearn.....................................         11
Mr. Chase......................................          9
Mr. Davis......................................          9
Mr. Liu........................................          9
Mr. Stoppelmoor................................          9
MS IES Comparables.............................         61
MS WPLH Comparables............................         61
Name Change Amendment..........................          2
Net Income Multiple............................         57
New IPC........................................          i
New IPC Charter................................          i
New IPC Common Stock...........................          i
New IPC Preference Stock.......................        107
New IPC Preferred Stock........................          i
New Utilities..................................          i
New Utilities Common Stock.....................          i
Notice Date....................................        100
NRC............................................         13
NYSE...........................................        iii
Offer Price....................................        100
Option.........................................          6
Option Grantor.................................         99
Option Holders.................................         99
Option Shares..................................         99
Options........................................          6
Payor..........................................         98
Payors.........................................         98
PhSE...........................................        iii
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
PP&E...........................................         66
Projected Period...............................         56
PSE............................................        iii
Ratios.........................................          i
Representatives................................         93
Repurchase Period..............................        100
Restricted Shares..............................        101
Right..........................................        106
Rights Agreement...............................          i
Salomon Brothers...............................          9
Salomon Brothers Report........................         66
SB IES Comparable Group........................         67
SB IPC Comparable Group........................         66
SB WPLH Comparable Group.......................         66
SEC............................................        iii
Section 262....................................         80
Securities Act.................................        iii
SERP...........................................         71
S&P............................................        151
Stock Option Agreements........................          6
Stock Price....................................         66
Subsidiaries...................................         90
Target Party...................................         97
Trigger Payment................................        101
Utilities......................................          i
Utilities Common Stock.........................          i
Utilities Preferred Stock......................          i
Utilities Reincorporation Merger...............          i
WBCL...........................................          4
Wisconsin Commission...........................         13
Wisconsin Holding Company Act..................         14
WP&L...........................................          i
WP&L MIP.......................................        148
WP&L Preferred Stock...........................         15
WP&L Savings Plan..............................         27
WPLH...........................................          i
WPLH Board.....................................         ii
WPLH Bylaws....................................          4
WPLH Charter...................................         ii
WPLH Charter Amendments........................          2
WPLH Committee.................................        147
WPLH Common Stock..............................          i
WPLH DRIP......................................         27
WPLH Joint Ventures............................         90
WPLH Meeting...................................         ii
WPLH MIP.......................................        149
WPLH Options...................................         99
WPLH Record Date...............................          3
WPLH Subsidiaries..............................         90
</TABLE>
 
                                       x
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
                             INDEX OF DEFINED TERMS
<TABLE>
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
1935 Act.......................................          i
1992 Act.......................................         31
1995 EPS Ratio.................................         55
1996 EPS Ratio.................................         55
Acquisition....................................          i
Antitrust Division.............................         86
Atomic Energy Act..............................         13
Book Value Multiple............................         57
BSE............................................        iii
Business Combination...........................         96
CCK............................................        142
Certificates...................................          6
Class I........................................         93
Class II.......................................         93
Class III......................................         93
Closing........................................         87
Closing Date...................................         87
Code...........................................         12
Common Equity Ratio............................         55
Common Stock Amendment.........................          2
Comparable Merger Transactions.................         57
Confidentiality Agreement......................         97
Consulting Group...............................         36
CRANDIC........................................         57
CSE............................................        iii
DCF............................................         56
Delaware Business Combination Statute..........        119
Delaware Chancery Court........................         15
DGCL...........................................          4
Diversified....................................          1
Dividend Ratio.................................         55
Division.......................................         85
DRSPP Shares...................................         31
EBIT...........................................         56
EBIT Multiple..................................         57
EBITDA.........................................         57
EBITDA Multiple................................         57
Effective Time.................................          5
EHC............................................         56
Electric Utility MOE Transactions..............         62
Employment Agreements..........................         10
EPS............................................         55
ERISA..........................................         91
EWGs...........................................         31
Exchange Act...................................        iii
Exchange Agent.................................         89
FERC...........................................         13
FERC Application...............................         86
FTC............................................         86
 
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
Guaranty Plan..................................        150
HDC............................................          1
Historical Period..............................         56
HPI............................................         56
HSR Act........................................         13
IASD...........................................        137
IBCA...........................................          4
ICC............................................         13
IEA............................................         57
IES............................................          i
IES Board......................................         ii
IES Bylaws.....................................          4
IES Cancelled Shares...........................         88
IES Charter....................................          4
IES Common Stock...............................          i
IES Dissenting Shares..........................          i
IES Joint Ventures.............................         90
IES Meeting....................................         ii
IES Merger.....................................          i
IES Options....................................         99
IES Preferred Stock............................         15
IES Ratio......................................          i
IES Record Date................................          3
IES Stock Award................................         96
IES Stock Option...............................         95
IES Subsidiaries...............................         90
Indemnified Parties............................         94
Interested Contracts or Transactions...........        114
Interstate Energy..............................          i
Interstate Energy Board........................         10
Interstate Energy Bylaws.......................         16
Interstate Energy Charter......................         16
Interstate Energy Common Stock.................          i
Iowa Southern Utilities........................        151
IPC............................................          i
IPC Board......................................         ii
IPC Bonds......................................        108
IPC Bylaws.....................................          4
IPC Cancelled Shares...........................         88
IPC Charter....................................          i
IPC Charter Amendment..........................          3
IPC Common Stock...............................          i
IPC Direct Merger..............................          i
IPC Dissenting Shares..........................          i
IPC DRSPP......................................         31
IPC Executives.................................         71
IPC Joint Ventures.............................         90
IPC Meeting....................................         ii
IPC Merger.....................................          i
</TABLE>
 
                                       ix
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
<TABLE>
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
IPC Options....................................         99
IPC Preference Stock...........................        107
IPC Preferred Stock............................          i
IPC Ratio......................................          i
IPC Record Date................................          3
IPC Reincorporation Effective Time.............          5
IPC Reincorporation Merger.....................          i
IPC Severance Agreements.......................         71
IPC Subsidiaries...............................         90
IUB............................................         13
Joint Registration Statement...................        iii
Liu Agreement..................................        152
LTM............................................         57
Market/Offer Price.............................        100
Merger Agreement...............................          i
Mergers........................................          i
Merrill LyGnch.................................          9
Merrill Lynch Opinion..........................         53
McLeod.........................................          5
McLeod Contingency.............................          5
Minnesota Commission...........................         13
ML IES Comparables.............................         55
ML IPC Comparables.............................         55
ML WPLH Comparables............................         55
Morgan Stanley.................................          9
Mr. Ahearn.....................................         11
Mr. Chase......................................          9
Mr. Davis......................................          9
Mr. Liu........................................          9
Mr. Stoppelmoor................................          9
MS IES Comparables.............................         61
MS WPLH Comparables............................         61
Name Change Amendment..........................          2
Net Income Multiple............................         57
New IPC........................................          i
New IPC Charter................................          i
New IPC Common Stock...........................          i
New IPC Preference Stock.......................        107
New IPC Preferred Stock........................          i
New Utilities..................................          i
New Utilities Common Stock.....................          i
Notice Date....................................        100
NRC............................................         13
NYSE...........................................        iii
Offer Price....................................        100
Option.........................................          6
Option Grantor.................................         99
Option Holders.................................         99
Option Shares..................................         99
Options........................................          6
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
Payor..........................................         98
Payors.........................................         98
Period of Consulting...........................        152
Period of Employment...........................        152
PhSE...........................................        iii
PP&E...........................................         66
Projected Period...............................         56
PSE............................................        iii
Ratios.........................................          i
Representatives................................         93
Repurchase Period..............................        100
Restricted Shares..............................        101
Right..........................................        106
Rights Agreement...............................          i
Salomon Brothers...............................          9
Salomon Brothers Report........................         66
SB IES Comparable Group........................         67
SB IPC Comparable Group........................         66
SB WPLH Comparable Group.......................         66
SEC............................................        iii
Section 262....................................         80
Securities Act.................................        iii
SERP...........................................         71
Stock Option Agreements........................          6
Stock Price....................................         66
Subsidiaries...................................         90
Target Party...................................         97
Trigger Payment................................        101
Utilities......................................          i
Utilities Common Stock.........................          i
Utilities Preferred Stock......................          i
Utilities Reincorporation Merger...............          i
WBCL...........................................          4
Wisconsin Commission...........................         13
Wisconsin Holding Company Act..................         14
WP&L...........................................          i
WP&L Preferred Stock...........................         15
WP&L Savings Plan..............................         27
WPLH...........................................          i
WPLH Board.....................................         ii
WPLH Bylaws....................................          4
WPLH Charter...................................         ii
WPLH Charter Amendments........................          2
WPLH Common Stock..............................          i
WPLH DRIP......................................         27
WPLH Joint Ventures............................         90
WPLH Meeting...................................         ii
WPLH Options...................................         99
WPLH Record Date...............................          3
WPLH Subsidiaries..............................         90
</TABLE>
 
                                       x
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
                             INDEX OF DEFINED TERMS
<TABLE>
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
1935 Act.......................................          i
1992 Act.......................................         31
1995 EPS Ratio.................................         55
1996 EPS Ratio.................................         55
Acquisition....................................          i
Antitrust Division.............................         86
Atomic Energy Act..............................         13
Book Value Multiple............................         57
BSE............................................        iii
Business Combination...........................         96
Certificates...................................          6
CEOs...........................................        141
Class I........................................         93
Class II.......................................         93
Class III......................................         93
Closing........................................         87
Closing Date...................................         87
Code...........................................         12
Common Equity Ratio............................         55
Common Stock Amendment.........................          2
Comparable Merger Transactions.................         57
Confidentiality Agreement......................         97
Consulting Group...............................         36
CRANDIC........................................         57
CSE............................................        iii
DCF............................................         56
Delaware Business Combination Statute..........        119
Delaware Chancery Court........................         15
DGCL...........................................          4
Diversified....................................          1
Dividend Ratio.................................         55
Division.......................................         85
DRSPP Shares...................................         31
EBIT...........................................         56
EBIT Multiple..................................         57
EBITDA.........................................         57
EBITDA Multiple................................         57
Effective Time.................................          5
EHC............................................         56
Electric Utility MOE Transactions..............         62
Employment Agreements..........................         10
EPS............................................         55
ERISA..........................................         91
EWGs...........................................         31
Exchange Act...................................        iii
Exchange Agent.................................         89
FERC...........................................         13
FERC Application...............................         86
FTC............................................         86
 
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
HDC............................................          1
Historical Period..............................         56
HPI............................................         56
HSR Act........................................         13
IBCA...........................................          4
ICC............................................         13
IEA............................................         57
IES............................................          i
IES Board......................................         ii
IES Bylaws.....................................          4
IES Cancelled Shares...........................         88
IES Charter....................................          4
IES Common Stock...............................          i
IES Dissenting Shares..........................          i
IES Joint Ventures.............................         90
IES Meeting....................................         ii
IES Merger.....................................          i
IES Options....................................         99
IES Preferred Stock............................         15
IES Ratio......................................          i
IES Record Date................................          3
IES Stock Award................................         96
IES Stock Option...............................         95
IES Subsidiaries...............................         90
Indemnified Parties............................         94
Interested Contracts or Transactions...........        114
Interstate Energy..............................          i
Interstate Energy Board........................         10
Interstate Energy Bylaws.......................         16
Interstate Energy Charter......................         16
Interstate Energy Common Stock.................          i
IPC............................................          i
IPC Board......................................         ii
IPC Bonds......................................        108
IPC Bylaws.....................................          4
IPC Cancelled Shares...........................         88
IPC Charter....................................          i
IPC Charter Amendment..........................          3
IPC Common Stock...............................          i
IPC Direct Merger..............................          i
IPC Dissenting Shares..........................          i
IPC DRSPP......................................         31
IPC Executives.................................         71
IPC Joint Ventures.............................         90
IPC Meeting....................................         ii
IPC Merger.....................................          i
IPC Options....................................         99
IPC Preference Stock...........................        107
IPC Preferred Stock............................          i
</TABLE>
 
                                       ix
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
<TABLE>
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
IPC Ratio......................................          i
IPC Record Date................................          3
IPC Reincorporation Effective Time.............          5
IPC Reincorporation Merger.....................          i
IPC Severance Agreements.......................         71
IPC Subsidiaries...............................         90
IUB............................................         13
Joint Registration Statement...................        iii
LTM............................................         57
Market/Offer Price.............................        100
Merger Agreement...............................          i
Mergers........................................          i
Merrill Lynch..................................          9
Merrill Lynch Opinion..........................         53
McLeod.........................................          5
McLeod Contingency.............................          5
Minnesota Commission...........................         13
ML IES Comparables.............................         55
ML IPC Comparables.............................         55
ML WPLH Comparables............................         55
Morgan Stanley.................................          9
Mr. Ahearn.....................................         11
Mr. Chase......................................          9
Mr. Davis......................................          9
Mr. Liu........................................          9
Mr. Stoppelmoor................................          9
MS IES Comparables.............................         61
MS WPLH Comparables............................         61
Name Change Amendment..........................          2
Net Income Multiple............................         57
New IPC........................................          i
New IPC Charter................................          i
New IPC Common Stock...........................          i
New IPC Preference Stock.......................        107
New IPC Preferred Stock........................          i
New Utilities..................................          i
New Utilities Common Stock.....................          i
Notice Date....................................        100
NRC............................................         13
NYSE...........................................        iii
Offer Price....................................        100
Option.........................................          6
Option Grantor.................................         99
Option Holders.................................         99
Option Shares..................................         99
Options........................................          6
Payor..........................................         98
Payors.........................................         98
<CAPTION>
                                                   PAGE
                                                 ---------
<S>                                              <C>
PhSE...........................................        iii
PP&E...........................................         66
Projected Period...............................         56
PSE............................................        iii
Ratios.........................................          i
Representatives................................         93
Repurchase Period..............................        100
Restricted Shares..............................        101
Right..........................................        106
Rights Agreement...............................          i
Salomon Brothers...............................          9
Salomon Brothers Report........................         66
SB IES Comparable Group........................         67
SB IPC Comparable Group........................         66
SB WPLH Comparable Group.......................         66
SEC............................................        iii
Section 262....................................         80
Securities Act.................................        iii
SERP...........................................         71
SRP............................................        144
Stock Option Agreements........................          6
Stock Price....................................         66
Subsidiaries...................................         90
Target Party...................................         97
Trigger Payment................................        101
Utilities......................................          i
Utilities Common Stock.........................          i
Utilities Preferred Stock......................          i
Utilities Reincorporation Merger...............          i
WBCL...........................................          4
Wisconsin Commission...........................         13
Wisconsin Holding Company Act..................         14
WP&L...........................................          i
WP&L Preferred Stock...........................         15
WP&L Savings Plan..............................         27
WPLH...........................................          i
WPLH Board.....................................         ii
WPLH Bylaws....................................          4
WPLH Charter...................................         ii
WPLH Charter Amendments........................          2
WPLH Common Stock..............................          i
WPLH DRIP......................................         27
WPLH Joint Ventures............................         90
WPLH Meeting...................................         ii
WPLH Options...................................         99
WPLH Record Date...............................          3
WPLH Subsidiaries..............................         90
</TABLE>
 
                                       x
<PAGE>
                                    SUMMARY
 
    THE  FOLLOWING IS A BRIEF SUMMARY  OF CERTAIN IMPORTANT TERMS AND CONDITIONS
OF  THE  MERGERS  AND  RELATED  INFORMATION.   AS  USED  IN  THIS  JOINT   PROXY
STATEMENT/PROSPECTUS,   THE  TERMS  "WPLH,"  "IES"   AND  "IPC"  REFER  TO  SUCH
CORPORATIONS, RESPECTIVELY, AND,  EXCEPT WHERE THE  CONTEXT OTHERWISE  REQUIRES,
SUCH  ENTITIES AND THEIR RESPECTIVE SUBSIDIARIES.  THIS SUMMARY DOES NOT PURPORT
TO BE  COMPLETE AND  IS  QUALIFIED IN  ITS ENTIRETY  BY  REFERENCE TO  THE  MORE
DETAILED    INFORMATION    CONTAINED    ELSEWHERE    IN    THIS    JOINT   PROXY
STATEMENT/PROSPECTUS, THE ANNEXES HERETO  AND THE DOCUMENTS INCORPORATED  HEREIN
BY  REFERENCE. SHAREOWNERS ARE URGED TO  REVIEW CAREFULLY THE ENTIRE JOINT PROXY
STATEMENT/PROSPECTUS.
 
THE PARTIES
 
    INTERSTATE ENERGY.  The WPLH Charter will be amended immediately prior to or
upon consummation of the Mergers to, among other things, change the name of WPLH
to "Interstate  Energy  Corporation."  Interstate Energy  will  be  the  holding
company  for IPC or New IPC, as the  case may be, and the operating subsidiaries
of WPLH  and IES  following the  Mergers.  Interstate Energy  will be  a  public
utility  holding company registered under the 1935 Act. See "Regulatory Matters"
and "Interstate Energy Following the Mergers." The principal executive office of
Interstate Energy  will  be located  at  222 West  Washington  Avenue,  Madison,
Wisconsin 53703, telephone number (608) 252-3311.
 
    WPLH.   WPLH, incorporated under the laws of the State of Wisconsin in 1981,
is the  holding company  for WP&L  and its  utility-related subsidiary  and  for
Heartland  Development Corporation  ("HDC"), the  parent corporation  for WPLH's
non-utility  businesses.  WP&L  is  a  public  utility  engaged  principally  in
generating,  purchasing, distributing and selling electric energy in portions of
southern and central Wisconsin. WP&L also purchases, distributes, transports and
sells natural gas in parts of such areas and supplies water in two  communities.
A  wholly-owned  subsidiary of  WP&L supplies  electric,  gas and  water service
principally in Winnebago  County, Illinois. HDC  and its principal  subsidiaries
are  engaged  in  business  development  in  three  major  areas:  environmental
engineering  and  consulting;  affordable  housing;  and  energy  services.  The
principal  executive office  of WPLH  and WP&L  is, and  the principal executive
office of  WP&L after  the  Effective Time  (as  hereinafter defined)  will  be,
located  at  222 West  Washington  Avenue, Madison,  Wisconsin  53703, telephone
number (608) 252-3311. See "Selected Information Concerning WPLH, IES and IPC --
Business of WPLH" and "Interstate Energy Following the Mergers -- Operations."
 
    IES.  IES, incorporated under  the laws of the State  of Iowa in 1986, is  a
holding  company for Utilities and for IES Diversified Inc. ("Diversified"), the
parent corporation  for most  of IES's  non-utility businesses.  Utilities is  a
public  utility engaged principally in  generating, purchasing, distributing and
selling electric  energy  in portions  of  the  State of  Iowa.  Utilities  also
purchases,  distributes,  transports  and  sells  natural  gas  in  its  service
territory. The  shares of  Utilities Preferred  Stock are  currently  registered
under  Section 12(g) of the Exchange Act  and, as such, Utilities is required to
make periodic and other filings with the SEC. In the event that the Mergers  can
be  effected without  consummating the  Utilities Reincorporation  Merger, it is
expected that  the  Utilities  Preferred  Stock  would  remain  outstanding  and
unchanged  as a  result of the  Mergers and  that Utilities, as  a subsidiary of
Interstate Energy, would remain a reporting  company under the Exchange Act.  In
the  event  that the  consummation of  the  Utilities Reincorporation  Merger is
necessary for regulatory reasons and the Utilities Preferred Stock is  redeemed,
it  is anticipated  that New  Utilities (as  the successor  to Utilities  in the
Utilities  Reincorporation  Merger)  would  not  be  subject  to  the  reporting
requirements  of the Exchange Act  and would not make  filings on its own behalf
with the SEC.  Diversified and  its subsidiaries engage  in various  non-utility
operations,  including  oil and  natural  gas production  and  marketing, energy
services, railroad and other transportation  services in the Midwest, and  local
real  estate development. The principal executive office of IES and Utilities is
located at IES Tower, 200 First Street S.E., Cedar Rapids, Iowa 52401, telephone
number (319) 398-4411. See "Selected Information Concerning WPLH, IES and IPC --
Business of IES" and "Interstate Energy Following the Mergers -- Operations."
 
                                       1
<PAGE>
    IPC.  IPC, an operating public  utility incorporated in 1925 under the  laws
of  the State of Delaware, is engaged in the generation, purchase, transmission,
distribution and  sale of  electric energy.  IPC owns  property in  portions  of
twenty-five counties in the northern and northeastern parts of Iowa, in portions
of  twenty-two counties in  the southern part  of Minnesota, and  in portions of
four counties in northwestern Illinois. IPC also engages in the distribution and
sale of natural  gas in  Albert Lea, Minnesota;  Clinton, Mason  City and  Clear
Lake,  Iowa; Fulton and Savanna, Illinois; and in a number of smaller Minnesota,
Iowa and Illinois communities, and in  the transportation of natural gas  within
Iowa,  Minnesota and in  interstate commerce. The  principal executive office of
IPC is located at 1000 Main Street, Dubuque, Iowa 52001, telephone number  (319)
582-5421.  In  the event  the IPC  Direct Merger  is consummated,  the principal
executive office of IPC after the Effective Time will continue to be located  at
such address. See "Selected Information Concerning WPLH, IES and IPC -- Business
of IPC" and "Interstate Energy Following the Mergers -- Operations."
 
    NEW IPC.  New IPC is a Wisconsin corporation which was created to effect the
IPC  Reincorporation Merger in the event  such merger is required for regulatory
purposes. It has, and prior  to the Mergers will  have, no operations except  as
contemplated  by the Merger  Agreement. The audited  financial statements of New
IPC are attached as Annex S. IPC is the sole shareowner of New IPC. Pursuant  to
the  Merger Agreement, in the event that the IPC Reincorporation Merger is to be
effected, immediately prior  to the  consummation of  the Mergers  New IPC  will
acquire  certain utility assets from WP&L. The principal executive office of New
IPC is, and  after the  Effective Time  will be,  located at  1000 Main  Street,
Dubuque,  Iowa 52001, telephone number (319) 582-5421. See "The Merger Agreement
- -- The Mergers" and "Interstate Energy Following the Mergers -- Operations."
 
    NEW UTILITIES.  New Utilities will be a Wisconsin corporation which will  be
created  to effect the Utilities Reincorporation Merger in the event such merger
is required  for regulatory  purposes. Prior  to the  Mergers, it  will have  no
operations  except as contemplated by the Merger Agreement. IES will be the sole
shareowner of New Utilities. Pursuant to the Merger Agreement, in the event that
the Utilities Reincorporation Merger is to be effected, immediately prior to the
consummation of the Mergers  New Utilities will  acquire certain utility  assets
from  WP&L. The principal executive  office of New Utilities  will be located at
IES Tower, 200  First Street S.E.,  Cedar Rapids, Iowa  52401, telephone  number
(319) 398-4411. See "The Merger Agreement -- The Mergers" and "Interstate Energy
Following the Mergers -- Operations."
 
    ACQUISITION.   Acquisition is  a Wisconsin corporation  which was created to
effect the IPC Merger or the IPC Direct Merger, as the case may be. It has,  and
prior  to the  Mergers will  have, no operations  except as  contemplated by the
Merger Agreement.  WPLH is  the sole  shareowner of  Acquisition. The  principal
executive  office  of  Acquisition is  located  at 222  West  Washington Avenue,
Madison, Wisconsin  53703,  telephone number  (608)  252-3311. See  "The  Merger
Agreement -- The Mergers."
 
THE MEETINGS
 
    WPLH.   At the WPLH Meeting, the holders  of WPLH Common Stock will be asked
to consider and vote upon proposals (i) to approve the Merger Agreement and  the
transactions  contemplated thereby, including, among  other things, the issuance
of shares of Interstate Energy Common Stock pursuant to the terms of the  Merger
Agreement, (ii) to approve the amendments to the WPLH Charter to change the name
of  WPLH to "Interstate Energy Corporation" (the "Name Change Amendment") and to
increase the number of shares of WPLH Common Stock authorized for issuance  from
100,000,000  to 200,000,000 (the "Common Stock Amendment," and together with the
Name Change Amendment, the "WPLH Charter Amendments"), (iii) to elect a total of
three directors for terms expiring at the 1999 annual meeting of shareowners  of
WPLH  or until  their successors  are duly  elected and  qualified, and  (iv) to
appoint Arthur Andersen LLP as independent auditors for WPLH for the year ending
December 31, 1996. Pursuant to the Merger Agreement, consummation of the Mergers
is conditioned  upon  approval of  proposals  (i) and  (ii)  above, but  is  not
conditioned  upon approval by the shareowners of WPLH of any other proposal. See
"Meetings, Voting and Proxies -- The WPLH Meeting."
 
                                       2
<PAGE>
    The WPLH Meeting is  scheduled to be held  immediately following the  annual
meeting  of shareowners of WP&L which will  be held at 10:00 a.m., Central Time,
on Thursday, September 5, 1996 at the  Dane County Expo Center, 1881 Expo  Mall,
Madison,  Wisconsin. The WPLH Board has fixed  the close of business on July 10,
1996 as  the record  date (the  "WPLH  Record Date")  for the  determination  of
holders  of WPLH  Common Stock  entitled to notice  of and  to vote  at the WPLH
Meeting.
 
    The WPLH  Board, by  a unanimous  vote of  the directors  then present,  has
approved  the Merger  Agreement and  the transactions  contemplated thereby, and
each of the WPLH Charter Amendments,  and recommends that WPLH shareowners  vote
FOR  approval  of the  Merger  Agreement (including  the  issuance of  shares of
Interstate Energy Common Stock pursuant to  the terms of the Merger  Agreements)
and  FOR approval of each of the  WPLH Charter Amendments. In addition, the WPLH
Board unanimously recommends that WPLH shareowners vote FOR the election of  the
nominated  WPLH  directors and  FOR the  appointment of  Arthur Andersen  LLP as
WPLH's independent auditors.
 
    IES.  At the IES Meeting, the holders  of IES Common Stock will be asked  to
consider  and vote upon  proposals (i) to  approve the Merger  Agreement and the
transactions contemplated thereby,  and (ii)  to elect nine  directors to  serve
until  the next annual  meeting or until  their successors are  duly elected and
qualified. Pursuant  to the  Merger Agreement,  consummation of  the Mergers  is
conditioned  upon approval  of proposal (i)  above, but is  not conditioned upon
approval by the shareholders of IES of any other proposal. See "Meetings, Voting
and Proxies -- The IES Meeting."
 
    The IES Meeting  is scheduled to  be held  at 10:00 a.m.,  Central Time,  on
Thursday,  September 5, 1996 at the Collins Plaza Hotel, 1200 Collins Road N.E.,
Cedar Rapids, Iowa. The IES  Board has fixed the close  of business on July  10,
1996 as the record date (the "IES Record Date") for the determination of holders
of IES Common Stock entitled to notice of and to vote at the IES Meeting.
 
    The  IES  Board, by  a unanimous  vote  of the  directors then  present, has
approved the Merger  Agreement and  the transactions  contemplated thereby,  and
recommends  that IES shareholders vote FOR  approval of the Merger Agreement. In
addition, the IES Board  unanimously recommends that  IES shareholders vote  FOR
the election of the nominated IES directors.
 
    IPC.   At the IPC Meeting, the holders  of IPC Common Stock will be asked to
consider and vote  upon proposals (i)  to approve the  Merger Agreement and  the
transactions  contemplated  thereby, (ii)  to approve  an  amendment to  the IPC
Charter to provide that each share of IPC Preferred Stock outstanding from  time
to time will have one vote, voting together as one class with the holders of IPC
Common  Stock (except as otherwise required by applicable law or as specifically
set forth in  the IPC  Charter), on all  matters to  come before a  vote of  the
stockholders  of IPC (the "IPC Charter Amendment"), and (iii) to elect two Class
II directors to  hold office  for a  term of three  years expiring  at the  1999
annual meeting of stockholders of IPC or until their respective successors shall
have  been duly elected  and qualified. Holders  of IPC Preferred  Stock are not
entitled to vote on the proposed amendment  to the IPC Charter. Pursuant to  the
Merger  Agreement, consummation of  the Mergers is  conditioned upon approval of
proposals (i)  and (ii)  above, but  is  not conditioned  upon approval  by  the
stockholders  of IPC of any other proposal. See "Meetings, Voting and Proxies --
The IPC Meeting."
 
    The IPC Meeting  is scheduled to  be held  at 10:00 a.m.,  Central Time,  on
Thursday,  September 5,  1996 at  the Holiday Inn  Dubuque Five  Flags, 450 Main
Street, Dubuque, Iowa. The IPC Board has fixed the close of business on July 10,
1996 as the record date (the "IPC Record Date") for the determination of holders
of IPC Common Stock entitled to notice of and to vote at the IPC Meeting.
 
    The IPC Board, by  a unanimous vote, has  approved the Merger Agreement  and
has  determined that  the IPC  Charter Amendment  is advisable,  and accordingly
recommends that IPC stockholders vote FOR  approval of the Merger Agreement  and
FOR  approval  of  the  IPC  Charter  Amendment.  In  addition,  the  IPC  Board
unanimously recommends  that  IPC stockholders  vote  FOR the  election  of  the
nominated IPC directors.
 
                                       3
<PAGE>
REQUIRED VOTE
 
    WPLH.    As  provided  under the  Wisconsin  Business  Corporation  Law (the
"WBCL"), the  WPLH  Charter and  the  bylaws of  WPLH  (the "WPLH  Bylaws"),  as
applicable:  (i) the affirmative vote of a  majority of the votes entitled to be
cast by the holders of the outstanding  shares of WPLH Common Stock entitled  to
vote  thereon is  required for approval  of the Merger  Agreement (including the
issuance of shares of  Interstate Energy Common Stock  pursuant to the terms  of
the  Merger Agreement),  (ii) the  affirmative vote of  a majority  of the votes
entitled to  be  cast  by  the  holders of  the  shares  of  WPLH  Common  Stock
represented  in person  or by  proxy at  the WPLH  Meeting and  entitled to vote
thereon is required for approval of each of the WPLH Charter Amendments, (iii) a
plurality of the votes cast at the WPLH Meeting is required for the election  of
directors  and (iv) the affirmative vote of  a majority of the votes entitled to
be cast by the holders of the shares of WPLH Common Stock represented in  person
or  by proxy  at the WPLH  Meeting and entitled  to vote thereon  is required to
appoint Arthur Andersen LLP as WPLH's  independent auditors. On the WPLH  Record
Date, there were 30,795,260 shares of WPLH Common Stock outstanding and entitled
to  vote. As of the WPLH Record  Date, directors and executive officers of WPLH,
together with their affiliates as a group, owned less than 1% of the issued  and
outstanding  shares of WPLH  Common Stock. See "Meetings,  Voting and Proxies --
The WPLH Meeting."
 
    IES.  As provided under the Iowa Business Corporation Act (the "IBCA"),  the
Restated  Articles of Incorporation of IES (the "IES Charter") and the bylaws of
IES (the "IES Bylaws"), as applicable: (i) the affirmative vote of a majority of
the votes entitled  to be  cast by  the holders of  shares of  IES Common  Stock
entitled  to vote thereon is  required for approval of  the Merger Agreement and
(ii) the affirmative vote of a majority of the votes entitled to be cast by  the
holders  of the shares of IES Common Stock  represented in person or by proxy at
the IES Meeting and  entitled to vote  thereon is required  for the election  of
directors.  On the IES Record  Date, there were 29,923,233  shares of IES Common
Stock outstanding and entitled to vote. As of the IES Record Date, directors and
executive officers of IES, together with their affiliates as a group, owned less
than 1% of the issued and outstanding shares of IES Common Stock. See "Meetings,
Voting and Proxies -- The IES Meeting."
 
    IPC.  As provided under the  Delaware General Corporation Law (the  "DGCL"),
the IPC Charter and the bylaws of IPC (the "IPC Bylaws"), as applicable: (i) the
affirmative  vote of a majority of the votes  entitled to be cast by the holders
of shares of IPC Common Stock is  required for approval of the Merger  Agreement
and  the approval of the IPC Charter Amendment and (ii) a plurality of the votes
cast at the IPC Meeting  is required for the election  of directors. On the  IPC
Record  Date, there  were 9,595,028 shares  of IPC Common  Stock outstanding and
entitled to vote. As of the IPC Record Date, directors and executive officers of
IPC, together with their affiliates as a group, owned less than 1% of the issued
and outstanding shares of IPC Common Stock. See "Meetings, Voting and Proxies --
The IPC Meeting."
 
THE MERGERS
 
    Subject to an  alternative structure described  below, the Merger  Agreement
provides  for (a) the IES Merger in which  IES will be merged with and into WPLH
with WPLH to be the surviving corporation and (b) the IPC Direct Merger in which
Acquisition will  be merged  with and  into IPC  with IPC  to be  the  surviving
corporation.  However,  in the  event that  the parties  determine that  the IPC
Reincorporation Merger and the Utilities Reincorporation Merger are required for
regulatory purposes, the Merger  Agreement provides that  those mergers will  be
consummated,  followed by  the IPC  Merger and the  IES Merger.  Pursuant to the
Merger Agreement (i)  each outstanding  share of  IES Common  Stock (other  than
shares  owned directly  or indirectly  by WPLH,  IES or  IPC and  IES Dissenting
Shares) will be converted  into the right to  receive 1.01 shares of  Interstate
Energy Common Stock; (ii) each outstanding share of IPC Common Stock (other than
shares owned directly or indirectly by WPLH, IES, or IPC) will be converted into
the  right to receive 1.11 shares of  Interstate Energy Common Stock; (iii) each
outstanding share of IPC  Preferred Stock (other than  shares owned directly  or
indirectly by WPLH, IES or IPC and other than IPC Dissenting Shares) will remain
outstanding  and  unchanged (including  with  respect to  the  additional voting
rights proposed to be
 
                                       4
<PAGE>
approved at  the IPC  Meeting) or,  in the  event that  the IPC  Reincorporation
Merger  is to be effected, will be converted into one share of New IPC Preferred
Stock with terms (including dividend rights) and designations under the New  IPC
Charter  substantially  identical  to  those  of  the  converted  shares  of IPC
Preferred Stock under the  IPC Charter, including  the additional voting  rights
proposed  to be approved at the IPC Meeting; (iv) each outstanding share of WPLH
Common Stock will remain  outstanding and unchanged as  one share of  Interstate
Energy  Common  Stock;  and  (v)  if  the  Utilities  Reincorporation  Merger is
effected, each outstanding  share of  Utilities Common Stock  will be  converted
into  one share of New Utilities  Common Stock. If the Utilities Reincorporation
Merger is  to  be  consummated,  it is  currently  anticipated  that  shares  of
Utilities  Preferred Stock then outstanding will  be redeemed by Utilities prior
to the consummation of  such merger. The redemption  of the Utilities  Preferred
Stock  would avoid the need to obtain a  class vote of the holders of such stock
to approve the Utilities Reincorporation  Merger. The Utilities Preferred  Stock
is  redeemable, in whole or in  part, at the option of  Utilities at any time or
from time to time on not less than  30 days' notice at $51.00 per share for  the
4.30%  Series and the 6.10% Series and at $50.25 per share for the 4.80% Series,
plus, in each case, dividends  accrued and unpaid to  and including the date  of
redemption.  See "The Mergers -- Redemption  of Utilities Preferred Stock." As a
result of the Mergers, the common  shareowners of WPLH, IES and IPC  immediately
prior  to the Mergers (except for holders  of IES Dissenting Shares) will all be
common shareowners of  Interstate Energy immediately  following consummation  of
the Mergers.
 
    The  Merger Agreement  also contemplated an  adjustment of the  IES Ratio to
1.01 from the initial ratio of 0.98 in the event that, prior to the consummation
of the  Mergers,  McLeod,  Inc., a  Delaware  corporation  in which  IES  has  a
significant  ownership  interest  ("McLeod"), (a)  completed  a  firm commitment
underwritten initial public offering of its Class A common stock at a per  share
price  of at least $13.00 (subject to adjustment) in which McLeod received gross
proceeds (exclusive  of  proceeds  from  shares  purchased  by  existing  McLeod
shareowners)  of at least $75 million  and (b) immediately following such public
offering the  Class  A common  stock  was registered  under  Section 12  of  the
Exchange  Act (the "McLeod Contingency"). On  June 14, 1996, McLeod completed an
initial public offering of 13.8 million shares of its Class A common stock at  a
price  to  the  public of  $20  per  share. The  McLeod  offering  satisfied the
conditions of  the  McLeod Contingency  and,  as a  result,  the IES  Ratio  was
automatically adjusted to 1.01. See "The Mergers -- Background of the Mergers."
 
    Pursuant  to the Merger Agreement, (a)  the IES Merger will become effective
at the  time  specified  in the  articles  of  merger filed  by  WPLH  with  the
Secretaries  of State of the States of Wisconsin and Iowa and (b) the IPC Direct
Merger will become effective at the time specified in the certificate of  merger
and  articles of merger filed by IPC with the Secretaries of State of the States
of Delaware and Wisconsin. If only the IES Merger and the IPC Direct Merger  are
to  be consummated, the term "Effective Time"  as used herein will mean the time
that the  IES  Merger  and  the  IPC  Direct  Merger  become  effective.  It  is
anticipated that in that case both the IES Merger and the IPC Direct Merger will
be  consummated  simultaneously.  If  the  IPC  Reincorporation  Merger  and the
Utilities Reincorporation Merger are  deemed by the parties  to be required  for
regulatory purposes, the IPC Reincorporation Merger will become effective at the
time  specified in the certificate of merger and articles of merger filed by New
IPC with the Secretaries of State of  the States of Delaware and Wisconsin  (the
"IPC  Reincorporation  Effective Time").  If the  IPC Reincorporation  Merger is
effected, (a) the IES Merger will then become effective at the time specified in
the articles of merger filed by IES with the Secretaries of State of the  States
of  Wisconsin and  Iowa; (b) the  IPC Merger  will become effective  at the time
specified in the articles of merger filed by New IPC with the Secretary of State
of the State  of Wisconsin; and  (c) the Utilities  Reincorporation Merger  will
become  effective at the time  specified in the articles  of merger filed by New
Utilities with the Secretaries of State of the States of Wisconsin and Iowa.  If
the  IPC Reincorporation Merger  is effected, the term  "Effective Time" as used
herein will mean the time that the IES Merger, the IPC Merger and the  Utilities
Reincorporation  Merger become  effective, which will  be subsequent  to the IPC
Reincorporation Effective Time.
 
    See "The Merger Agreement -- The Mergers."
 
                                       5
<PAGE>
EXCHANGE OF STOCK CERTIFICATES
 
    As soon as  practicable after the  Effective Time, the  exchange agent  will
mail  transmittal instructions to each holder of record of shares of IES and IPC
Common Stock at the  Effective Time, advising such  holder of the procedure  for
surrendering  such holder's certificates  (the "Certificates") which immediately
prior to the IPC  Reincorporation Effective Time or  the Effective Time, as  the
case  may be, represented  shares of IES  Common Stock or  IPC Common Stock that
were cancelled and  became instead  the right  to receive  shares of  Interstate
Energy Common Stock. Holders of Certificates, which prior to the Reincorporation
Effective  Time or the Effective Time, as the case may be, represented shares of
IES Common  Stock or  IPC Common  Stock, will  not be  entitled to  receive  any
payment  of dividends  or other distributions  on or payment  for any fractional
share with respect to their IES or IPC Certificates until such Certificates have
been surrendered  for  certificates  representing shares  of  Interstate  Energy
Common Stock. Cash will be paid to IES and IPC shareowners in lieu of fractional
shares  of Interstate Energy Common Stock. Holders of shares of IES Common Stock
and IPC Common  Stock should not  submit their stock  certificates for  exchange
until  a form of  letter of transmittal and  instructions therefor are received.
See "The Merger Agreement -- The Mergers."
 
    Holders of  IPC Preferred  Stock  do not  need  to exchange  their  existing
certificates   representing  shares  of  IPC   Preferred  Stock  for  new  stock
certificates. Shares of IPC Preferred  Stock (other than IPC Dissenting  Shares)
will  remain unchanged (including  with respect to  the additional voting rights
proposed to be approved  at the IPC Meeting)  and outstanding following the  IPC
Direct  Merger. In the event the IPC Reincorporation Merger is consummated, each
outstanding certificate representing shares of  IPC Preferred Stock (other  than
IPC  Dissenting Shares) immediately  prior to the  IPC Reincorporation Effective
Time will, from and after the IPC Reincorporation Effective Time, represent  the
same  number of shares  of the corresponding  series of New  IPC Preferred Stock
with terms (including dividend rates) and designations under the New IPC Charter
substantially identical to those of the converted shares of IPC Preferred  Stock
under  the IPC  Charter, including the  additional voting rights  proposed to be
approved  at  the   IPC  Meeting.  After   the  Effective  Time,   if  the   IPC
Reincorporation  Merger is effected,  new certificates reflecting  the fact that
New IPC  is  a  Wisconsin  corporation  will  be  issued  as  outstanding  stock
certificates  formerly representing shares of  IPC Preferred Stock are presented
for transfer.
 
    Shareowners  of  WPLH  do  not   need  to  exchange  their  existing   stock
certificates  for  new  stock  certificates  reflecting  WPLH's  name  change to
Interstate Energy. However, any WPLH shareowners desiring new stock certificates
may,  after  the  Effective  Time,  submit  their  existing  stock  certificates
representing  shares of  WPLH Common Stock  to the transfer  agent of Interstate
Energy to  obtain new  certificates. Each  outstanding certificate  representing
shares  of WPLH Common Stock immediately prior  to the Effective Time will, from
and after the Effective Time, represent the same number of shares of  Interstate
Energy Common Stock. After the Effective Time, new certificates bearing the name
of  Interstate Energy will be issued  as outstanding stock certificates formerly
representing shares of WPLH Common Stock are presented for transfer.
 
STOCK OPTION AGREEMENTS
 
    In connection with the execution and delivery of the Merger Agreement, WPLH,
IES and IPC entered  into reciprocal option  grantor/option holder stock  option
and trigger payment agreements (the "Stock Option Agreements") each granting the
other   two  parties  an  irrevocable   option  (individually  an  "Option"  and
collectively the "Options") to purchase, under certain circumstances, a  certain
percentage  of authorized but unissued shares  of the respective issuer's common
stock (representing up to an aggregate of 19.9% of the outstanding common  stock
of  such issuer on November 10, 1995), at an exercise price of $30.675 per share
in the case of WPLH Common Stock, $26.7125  per share in the case of IES  Common
Stock  and $28.9375 per share  in the case of IPC  Common Stock. The exercise of
the Options and  the effectiveness  of certain  provisions of  the Stock  Option
Agreements  are  subject to  certain conditions  described  in the  Stock Option
Agreements and in  the Merger Agreement.  See "The Stock  Options Agreements  --
General"  and "The Merger Agreement -- Termination Fees." In addition, the Stock
Option Agreements provide that the holder of an option has the right to  require
 
                                       6
<PAGE>
the  issuer thereof to repurchase  from the holder of the  Option (i) all or any
portion of the Option at any time the Option is exercisable at a price equal  to
the  amount of  the difference between  the Market/ Offer  Price (as hereinafter
defined) and the exercise price of the Option; and (ii) on or at any time  prior
to  May 10,  1997 (which  date may  be extended  to May  10, 1998  under certain
circumstances) all  or any  portion  of any  shares  purchased pursuant  to  the
Option.  In addition, the Stock  Option Agreements provide that  in the event an
Option becomes  exercisable  but  regulatory  approvals  relating  to  issuance,
acquisition  or exercise  of the  Option, if  any, have  not been  obtained, the
holder of the Option has the right  to demand from the issuer thereof an  amount
in  cash equal to the product of (a)  the number of shares the holder would have
received upon  exercise  of  the  Option and  (b)  the  difference  between  the
Market/Offer  Price and the exercise price of  the Option. See "The Stock Option
Agreements  --  Certain  Repurchases  and  Other  Payments."  The  Stock  Option
Agreements  are intended  to increase  the likelihood  that the  Mergers will be
consummated in accordance with  the terms of the  Merger Agreement and may  have
the effect of discouraging competing offers. See "The Stock Options Agreements."
 
    The  Options will generally become exercisable  at any time after the Merger
Agreement becomes  terminable by  the holder  of an  Option under  circumstances
which  could entitle  such holder  to termination  fees from  the issuer  of the
Option, including if there is a material, willful breach of the Merger Agreement
at any  time  which  a  third  party  has  proposed  to  consummate  a  business
combination  with the issuer of the Option or if, under certain circumstances, a
business combination with a third party  is consummated within two and  one-half
years  of  the  termination  of  the Merger  Agreement.  See  "The  Stock Option
Agreements."
 
    Further, the Stock Option Agreements contemplate the continuation of certain
standstill provisions and provide that any shares of any other party acquired or
otherwise beneficially owned must be voted for and against each matter submitted
to a shareowner  vote in the  same proportion  as the other  shareowners of  the
issuer  thereof vote for and  against such matter. See  "The Merger Agreement --
Standstill Provisions" and "The Stock Option Agreements -- Voting."
 
TREATMENT OF SHARES; RATIOS
 
    Each share of IES Common Stock  issued and outstanding immediately prior  to
the  Effective Time  (other than  IES Dissenting  Shares) will,  pursuant to the
Merger Agreement, be  cancelled and  converted into  the right  to receive  1.01
shares  of Interstate Energy Common Stock. In  the IPC Direct Merger, each share
of IPC Common Stock  issued and outstanding immediately  prior to the  Effective
Time will, pursuant to the Merger Agreement, be cancelled and converted into the
right  to receive 1.11  shares of Interstate  Energy Common Stock.  In the event
that the IPC Reincorporation Merger is effected, each share of IPC Common  Stock
issued  and outstanding immediately  prior to the  IPC Reincorporation Effective
Time will, pursuant to the Merger Agreement, be cancelled and converted into one
share of New IPC Common Stock which, in turn, will immediately be cancelled  and
converted  into the  right to  receive 1.11  shares of  Interstate Energy Common
Stock in  connection  with the  IPC  Merger. Each  share  of WPLH  Common  Stock
outstanding  immediately prior to the Effective  Time will, upon consummation of
the Mergers, remain outstanding and unchanged as one share of Interstate  Energy
Common Stock. Holders of IES Common Stock and IPC Common Stock will receive cash
in  lieu of  fractional shares  of Interstate  Energy Common  Stock. In  the IPC
Direct Merger, each share of  IPC Preferred Stock outstanding immediately  prior
to  the Effective  Time (other  than the IPC  Dissenting Shares)  will after the
Effective Time remain unchanged (including with respect to the additional voting
rights proposed to be approved at the IPC Meeting) and outstanding as a share of
IPC Preferred Stock. In  the event the IPC  Reincorporation Merger is  effected,
each  share  of IPC  Preferred Stock  outstanding immediately  prior to  the IPC
Reincorporation Effective Time  (other than  IPC Dissenting  Shares) will,  upon
consummation  of the Mergers, be  cancelled and converted into  one share of New
IPC Preferred Stock with terms (including dividend rates) and designations under
the New IPC Charter substantially identical to those of the IPC Preferred  Stock
under  the IPC  Charter, including the  additional voting rights  proposed to be
approved at the IPC Meeting. In the event the
 
                                       7
<PAGE>
Utilities Reincorporation Merger  is effected,  each share  of Utilities  Common
Stock  issued and outstanding immediately prior to the Effective Time will, upon
consummation of the Mergers,  be cancelled and converted  into one share of  New
Utilities Common Stock. See "The Merger Agreement -- The Mergers."
 
BACKGROUND
 
    For  a description  of the  background of the  Mergers, see  "The Mergers --
Background of the Mergers."
 
REASONS FOR THE MERGERS
 
    WPLH, IES and IPC believe that  the Mergers offer significant strategic  and
financial  benefits to each company and to their respective shareowners, as well
as to their employees and customers. These benefits include, among others:
 
    - Maintenance of competitive rates that  will improve the combined  entity's
      ability to meet the challenges of the increasingly competitive environment
      in the utility industry.
 
    - Reduced  operating costs  and expenditures  resulting from  integration of
      corporate and  administrative  functions,  including  the  elimination  of
      duplicative  positions,  limiting  duplicative  capital  expenditures  for
      administrative and customer service programs and information systems,  and
      savings in areas such as legal, audit and consulting fees.
 
    - Reduced  electric production costs  through the joint  dispatch of systems
      and natural gas supply savings through combined purchasing.
 
    - Greater purchasing  power  for  items  such  as  fuel  and  transportation
      services,  general and operational goods and services and the reduction of
      inventories.
 
    - More efficient pursuit of diversification into non-utility areas.
 
    - Increased  customer  diversity   and  geographic   diversity  of   service
      territories,  reducing exposure to local  changes in economic, competitive
      or climatic conditions.
 
    - Expanded management  resources and  ability to  select leadership  from  a
      larger and more diverse management pool.
 
    See  "The Mergers -- Reasons for  the Mergers; Recommendations of the Boards
of Directors."
 
RECOMMENDATIONS OF THE BOARD OF DIRECTORS
 
    WPLH.  The WPLH  Board, by a  unanimous vote of  the directors present,  has
approved  the  Merger  Agreement  and  the  transactions  contemplated  thereby,
believes that the terms of  the Mergers are fair to,  and in the best  interests
of,  WPLH's  shareowners,  has approved  each  of the  WPLH  Charter Amendments,
supports  the  election  of  the  nominated  WPLH  directors  and  supports  the
appointment  of Arthur Andersen LLP as  WPLH's independent auditors for the year
ending December 31, 1996. The WPLH Board recommends that the shareowners of WPLH
vote (i) FOR approval of the Merger Agreement (including the issuance of  shares
of  Interstate  Energy  Common  Stock  pursuant  to  the  terms  of  the  Merger
Agreement), (ii) FOR approval of each of the WPLH Charter Amendments, (iii)  FOR
the  election of the nominated  WPLH directors and (iv)  FOR the ratification of
the appointment of the independent auditors. The WPLH Board approved the  Merger
Agreement after consideration of a number of factors described under the heading
"The  Mergers  -- Reasons  for  the Mergers;  Recommendations  of the  Boards of
Directors." WPLH directors  Katharine C. Lyall  and Arnold M.  Nemirow were  not
present  at the WPLH Board  meeting at which the  Merger Agreement was initially
approved and WPLH director Milton  E. Neshek was not  present at the WPLH  Board
meeting at which the amendment to the Merger Agreement was approved.
 
    IES.   The  IES Board,  by a  unanimous vote  of the  directors present, has
approved  the  Merger  Agreement  and  the  transactions  contemplated  thereby,
believes  that the terms of  the Mergers are fair to,  and in the best interests
of,  IES's  shareholders,  and  supports  the  election  of  the  nominated  IES
directors.  The IES Board recommends  that the shareholders of  IES vote (i) FOR
approval of the Merger Agreement and the transactions contemplated thereby,  and
(ii) FOR the election of the
 
                                       8
<PAGE>
nominated  IES  directors. The  IES Board  approved  the Merger  Agreement after
consideration of a number of factors described under the heading "The Mergers --
Reasons for  the  Mergers; Recommendations  of  the Boards  of  Directors."  IES
shareholders are urged to consider those factors before making any decision with
respect  to their proxies. IES  director Dr. George Daly  was not present at the
IES Board meeting at which the Merger Agreement was initially approved. Dr. Daly
resigned as  an IES  director  prior to  the time  the  IES Board  approved  the
amendment to the Merger Agreement.
 
    IPC.   The IPC Board,  by unanimous vote, has  approved the Merger Agreement
and the  transactions  contemplated thereby,  believes  that the  terms  of  the
Mergers are fair to, and in the best interests of, IPC stockholders, has adopted
a  resolution  setting  forth  the  IPC  Charter  Amendment  and  declaring  its
advisability, and supports the election of the nominated IPC directors. The  IPC
Board  recommends that the IPC stockholders vote  (i) FOR approval of the Merger
Agreement and the transactions  contemplated thereby, (ii)  FOR approval of  the
IPC  Charter  Amendment,  and  (iii)  FOR  the  election  of  the  nominated IPC
directors. The IPC Board approved the Merger Agreement after consideration of  a
number  of factors described under  the heading "The Mergers  -- Reasons for the
Mergers; Recommendations of the Boards of Directors."
 
OPINIONS OF FINANCIAL ADVISORS
 
    WPLH.  Merrill Lynch, Pierce, Fenner & Smith Incorporated ("Merrill  Lynch")
delivered  to the WPLH Board its written  opinion dated November 10, 1995, which
was confirmed  in  a  written  opinion  dated  the  date  of  this  Joint  Proxy
Statement/Prospectus,  to the effect that, as of  such dates, and based upon the
assumptions made, matters considered and limits  of review as set forth in  such
opinions,  the Ratios  are fair, from  a financial  point of view,  to WPLH. The
written  opinion  of  Merrill  Lynch  dated   the  date  of  this  Joint   Proxy
Statement/Prospectus is attached hereto as Annex L and is incorporated herein by
reference. HOLDERS OF SHARES OF WPLH COMMON STOCK ARE URGED TO, AND SHOULD, READ
SUCH  OPINION IN  ITS ENTIRETY.  For a description  of the  assumptions made and
matters considered  by Merrill  Lynch  in reaching  its  opinions and  the  fees
received  and to be received  by Merrill Lynch, see  "The Mergers -- Opinions of
Financial Advisors" and Annex L.
 
    IES.  Morgan  Stanley &  Co. Incorporated ("Morgan  Stanley") delivered  its
oral  opinion on  November 10, 1995  to the IES  Board which was  confirmed in a
written opinion dated as of the date of this Joint Proxy Statement/Prospectus to
the IES Board to the effect that,  as of the respective dates of such  opinions,
and  based upon the procedures and subject to assumptions described therein, the
IES Ratio, taking into account the IPC Ratio, is fair from a financial point  of
view  to the holders of IES Common  Stock. The written opinion of Morgan Stanley
dated as of the date of this Joint Proxy Statement/Prospectus is attached hereto
as Annex M. HOLDERS OF SHARES OF IES COMMON STOCK ARE URGED TO, AND SHOULD, READ
SUCH OPINION IN  ITS ENTIRETY.  For a description  of the  assumptions made  and
matters  considered  by Morgan  Stanley in  reaching its  opinions and  the fees
received and to be received by Morgan  Stanley, see "The Mergers -- Opinions  of
Financial Advisors" and Annex M.
 
    IPC.   Salomon Brothers Inc ("Salomon  Brothers") delivered to the IPC Board
its written opinions dated November  10, 1995 and the  date of this Joint  Proxy
Statement/Prospectus  to  the effect  that, based  upon  and subject  to various
considerations set forth in  such opinions, as of  the respective dates of  such
opinions,  the IPC  Ratio is  fair to  the holders  of IPC  Common Stock  from a
financial point of view. The written opinion of Salomon Brothers dated the  date
of  this Joint Proxy Statement/ Prospectus is  attached hereto as Annex N and is
incorporated herein by  reference. HOLDERS  OF SHARES  OF IPC  COMMON STOCK  ARE
URGED  TO, AND SHOULD, READ  SUCH OPINION IN ITS  ENTIRETY. For a description of
the assumptions made and matters considered by Salomon Brothers in reaching  its
opinions  and the fees received and to be received by Salomon Brothers, see "The
Mergers -- Opinions of Financial Advisors" and Annex N.
 
INTERESTS OF CERTAIN PERSONS IN THE MERGERS
 
    EMPLOYMENT AGREEMENTS.  Each of Lee Liu, Chairman of the Board, President  &
Chief  Executive Officer of IES ("Mr. Liu"), Erroll B. Davis, Jr., President and
Chief Executive Officer of WPLH ("Mr. Davis"), Wayne H. Stoppelmoor, Chairman of
the Board, President and Chief Executive Officer of IPC ("Mr. Stoppelmoor"), and
Michael  R.   Chase,   Executive   Vice  President   of   IPC   ("Mr.   Chase"),
 
                                       9
<PAGE>
will enter into employment agreements with Interstate Energy or its subsidiaries
to   become  effective  upon  consummation   of  the  Mergers  (the  "Employment
Agreements"). Pursuant  to the  Employment  Agreements, Mr.  Liu will  serve  as
Chairman  of Interstate Energy for a period of two years following the Effective
Time and thereafter will retire as an officer of Interstate Energy, although  he
may continue to serve as a director. Mr. Davis will serve as President and Chief
Executive  Officer of Interstate Energy for a  period of two years following the
Effective Time and, for the three-year period thereafter and following Mr. Liu's
retirement, Mr.  Davis will  serve as  Chairman, President  and Chief  Executive
Officer  of Interstate  Energy. Mr. Stoppelmoor  will serve as  Vice Chairman of
Interstate Energy for  a period of  two years following  the Effective Time  and
thereafter  will  retire as  an officer  of Interstate  Energy, although  he may
continue to serve as a director. Mr. Chase will serve as President of New IPC or
IPC, as the case may be, from and after the Effective Time until the last day of
the calendar month immediately following the calendar month in which he  attains
age  62. See  "The Mergers  -- Interests  of Certain  Persons in  the Mergers --
Employment Agreements."
 
    SEVERANCE ARRANGEMENTS.  Each of WPLH, IES and IPC maintain or have  entered
into certain severance agreements under which certain benefits may become vested
and  certain payments  may become payable  in connection with  certain change in
control conditions which include the Mergers. WPLH has employment and  severance
agreements  with  each  of  thirteen  executives  of  WPLH  and  certain  of its
subsidiaries which  generally provide  for  certain benefits  in the  event  the
executive  is terminated following a change in control of WPLH (as defined). The
WPLH Board has authorized the amendment of each of the foregoing WPLH agreements
to provide specifically that the consummation  of the Mergers will constitute  a
change  in control in certain circumstances  for purposes of the agreements. IES
has severance agreements with  twelve executives of IES  and Utilities. Each  of
the  IES severance  agreements provides severance  payments and  benefits if the
employment of the covered executive is terminated following a change in control.
The Mergers  will  constitute  a  change in  control  under  the  IES  severance
agreements.  IPC has  change in control  severance agreements with  each of nine
senior executives of  IPC which generally  provide for certain  benefits in  the
event  the  executive  is  terminated  or  resigns  under  certain circumstances
following a change in control of IPC (as defined in the agreements). The Mergers
will constitute a  change in  control of IPC  for purposes  of such  agreements.
Based  on the compensation paid  to the executives of WPLH,  IES and IPC in 1995
and assuming the occurrence of a termination for which severance benefits  would
be  payable following  a change  of control,  the maximum  amounts payable under
these severance agreements to all of the executives of WPLH, IES or IPC, each as
a  group,  respectively,  would  be  approximately  $7,014,000,  $6,263,000  and
$2,800,000,  respectively. See "The  Mergers -- Interests  of Certain Persons in
the Mergers -- Severance Arrangements."
 
    BOARD OF  DIRECTORS.   The  Merger Agreement  provides that  the  Interstate
Energy   Board  of  Directors   (the  "Interstate  Energy   Board")  will,  upon
consummation of the  Mergers, consist of  fifteen persons, six  of whom will  be
designated  by WPLH, including Mr. Davis, six of whom will be designated by IES,
including Mr. Liu, and three  of whom will be  designated by IPC, including  Mr.
Stoppelmoor.  See "The Mergers -- Interests of Certain Persons in the Mergers --
Board of Directors."
 
    INDEMNIFICATION.   The parties  have  agreed in  the Merger  Agreement  that
Interstate  Energy will indemnify, to the fullest extent permitted by applicable
law, the present  and former officers,  directors and employees  of each of  the
parties  to the  Merger Agreement or  any of their  subsidiaries against certain
liabilities (i) arising out of actions or omissions occurring at or prior to the
Effective Time that  arise from  or are  based on  such service  as an  officer,
director  or employee; or (ii) that  are based on or arise  out of or pertain to
the transactions contemplated by the Merger Agreement, and to maintain  policies
of  directors' and officers' liability  insurance for a period  of not less than
six years after the Effective Time. To the fullest extent permitted by law, from
and after the Effective Time, all rights to indemnification existing in favor of
the employees, agents,  directors or  officers of WPLH,  IES and  IPC and  their
respective  subsidiaries with respect  to their activities as  such prior to the
Effective Time,  as provided  in  their respective  certificate or  articles  of
incorporation and bylaws, in effect on November 10, 1995, or otherwise in effect
on    November    10,   1995,    shall   survive    the   Mergers    and   shall
 
                                       10
<PAGE>
continue in full force and effect for a  period of not less than six years  from
the  Effective Time.  See "The  Mergers -- Interests  of Certain  Persons in the
Mergers -- Indemnification" and "The Merger Agreement -- Indemnification."
 
MANAGEMENT OF INTERSTATE ENERGY
 
    As provided in the Merger Agreement,  at the Effective Time, the  Interstate
Energy  Board will  consist of  fifteen directors,  six designated  by WPLH, six
designated by IES and three  designated by IPC. At  the Effective Time, Mr.  Liu
will become Chairman of Interstate Energy, Mr. Davis will be President and Chief
Executive  Officer of  Interstate Energy  and Mr.  Stoppelmoor will  become Vice
Chairman of Interstate Energy.  In addition, following  the Effective Time,  Mr.
Chase  will become President of New IPC or IPC, as the case may be, and Lance W.
Ahearn ("Mr. Ahearn") will become President  and Chief Operating Officer of  the
holding  company for the  non-utility businesses of  Interstate Energy. To date,
WPLH, IES  and IPC  have not  determined  the individuals,  in addition  to  the
foregoing,  who  will  be  designated  to  serve  as  directors  or  officers of
Interstate Energy or its subsidiaries as of the Effective Time. See "The Mergers
- -- Employment  Agreements"  and  "Interstate Energy  Following  the  Mergers  --
Management of Interstate Energy."
 
CONDITIONS TO THE MERGERS
 
    The  respective obligations of  WPLH, IES and IPC  to consummate the Mergers
are subject to the satisfaction  of certain conditions, including: the  approval
of  the Merger Agreement  by the shareowners of  each of WPLH,  IES and IPC; the
receipt of all material  governmental approvals; the  absence of any  injunction
that  prevents the consummation of  the Mergers; the listing  on the NYSE of the
shares of Interstate Energy Common Stock to  be issued pursuant to the terms  of
the  Merger  Agreement;  the qualification  of  the business  combination  to be
effected by the  Mergers as a  pooling of interests  transaction for  accounting
purposes;  the  accuracy  of the  representations  and warranties  of  the other
parties set forth in  the Merger Agreement  as of the  Closing Date (as  defined
herein)  (except for inaccuracies which would not reasonably be likely to result
in a  material adverse  effect); the  performance by  the other  parties in  all
material  respects, or waiver, of all obligations required to be performed under
the Merger  Agreement  and  the  Stock Option  Agreements;  the  receipt  of  an
officer's certificate from the other parties stating that certain conditions set
forth in the Merger Agreement have been satisfied, there having been no material
adverse effect on any other party; the receipt of opinions that the Mergers will
qualify as tax-free reorganizations; the receipt of certain material third-party
consents;  the  receipt of  letters from  affiliates of  the other  parties with
respect to transactions in securities of WPLH, IES or IPC; and the effectiveness
of the Joint Registration Statement. See "The Merger Agreement -- Conditions  to
Each Party's Obligation to Effect the Mergers."
 
RIGHTS TO TERMINATE, AMEND OR WAIVE CONDITIONS
 
    The   Merger  Agreement  may  be  terminated  under  certain  circumstances,
including: by mutual consent of WPLH, IES  and IPC; by any party if the  Mergers
are  not consummated by May 10, 1997 (which date may be extended to May 10, 1998
under certain circumstances); by any party if the requisite shareowner approvals
are not  obtained or  if  any state  or federal  law  or court  order  prohibits
consummation of the Mergers; by a non-breaching party if there occurs a material
breach of the Merger Agreement which is not cured within 20 days; or by a party,
under  certain circumstances, as a result of a more favorable third-party tender
offer or business combination  proposal with respect to  such party. The  Merger
Agreement  requires that termination  fees be paid  under certain circumstances,
including if there is a material, willful breach of the Merger Agreement or  if,
under  certain  circumstances,  a business  combination  with a  third  party is
consummated within  two and  one-half years  of the  termination of  the  Merger
Agreement. The aggregate termination fees under this provision together with the
amounts  payable under certain provisions of the Stock Option Agreements may not
exceed $40,000,000 payable by  each of WPLH and  IES and $20,000,000 payable  by
IPC.  See  "The  Merger  Agreement --  Termination,"  "The  Merger  Agreement --
Termination Fees" and "The Stock  Options Agreements -- Certain Repurchases  and
Other  Payments." The  Merger Agreement also  provides for  the reimbursement of
documented out-of-pocket expenses incurred by the non-breaching party or parties
in the event the Merger Agreement is terminated under certain circumstances.  In
the
 
                                       11
<PAGE>
event  that  the Merger  Agreement provides  for  expense reimbursement  and the
breach giving rise to  the termination of the  Merger Agreement is not  willful,
each   non-breaching   party  is   entitled   to  reimbursement   of  documented
out-of-pocket expenses, not to exceed  $5,000,000 for each non-breaching  party.
In  the event of a willful breach, the $5,000,000 limit on expense reimbursement
will not apply. The  Merger Agreement does not  provide for any modification  in
the  Ratios  due to  changes in  the operating  results, financial  condition or
trading prices of the WPLH  Common Stock, IES Common  Stock or IPC Common  Stock
between  the time of the execution of  the Merger Agreement and the consummation
of the transactions contemplated thereby.
 
    The Merger  Agreement may  be amended  by  the boards  of directors  of  the
parties at any time before or after its approval by the shareowners of WPLH, IES
and  IPC, but after any such approval, no  amendment may be made which alters or
changes (i) the amount or kind of shares, rights or the manner of conversion  of
such  shares, (ii)  the terms  or conditions  of the  Merger Agreement,  if such
alteration or  change, alone  or in  the aggregate,  would materially  adversely
affect  the rights of the WPLH, IES or IPC shareowners, or (iii) any term of the
WPLH, IES or IPC Charter, except for alterations or changes that could otherwise
be adopted by the Interstate Energy  Board without the further approval of  such
shareowners. See "The Merger Agreement -- Amendment and Waiver."
 
    At  any  time  prior to  the  Effective  Time, to  the  extent  permitted by
applicable  law,  the  conditions  to  WPLH's,  IES's  or  IPC's  obligation  to
consummate the Mergers may be waived by such party. Any determination to waive a
condition  would depend upon the facts and circumstances existing at the time of
such waiver  and would  be made  by the  waiving parties'  boards of  directors,
exercising  their  fiduciary  duties  to  their  shareowners.  See  "The  Merger
Agreement -- Amendment and Waiver."
 
CERTAIN FEDERAL INCOME TAX CONSEQUENCES
 
    WPLH's obligation to effect the Mergers is conditioned on the delivery of an
opinion to WPLH  from Foley  & Lardner, counsel  for WPLH,  IES's obligation  to
effect  the Mergers is conditioned  upon the delivery of  an opinion to IES from
Winthrop, Stimson, Putnam &  Roberts, counsel for IES,  and IPC's obligation  to
effect  the Mergers is conditioned  upon the delivery of  an opinion to IPC from
Milbank, Tweed, Hadley & McCloy, counsel for  IPC, each dated as of the  Closing
Date,  based upon  certain customary  representations and  assumptions set forth
therein, substantially to the effect that, for federal income tax purposes, each
of the  mergers  to  which such  party  or  its subsidiaries  is  a  constituent
constitutes  a tax-free reorganization  within the meaning  of Section 368(a) of
the Internal Revenue Code of 1986, as amended (the "Code").
 
    Subject to  the  approval  by  the  IPC  stockholders  of  the  IPC  Charter
Amendment,  and  provided  that there  shall  have  been no  adverse  changes in
applicable law or facts prior to the Effective Time, in general: (i) no gain  or
loss will be recognized by WPLH, IES, IPC, or Acquisition (or New IPC, Utilities
and  New Utilities, if applicable) pursuant to the Mergers; (ii) no gain or loss
will be recognized by holders  of IES Common Stock or  IPC Common Stock (or  New
IPC  Common Stock, if applicable) upon the exchange of their IES Common Stock or
IPC Common Stock (or New IPC Common Stock, if applicable) into Interstate Energy
Common Stock pursuant to the Mergers; (iii)  no gain or loss will be  recognized
by  holders of IPC Preferred  Stock (or New IPC  Preferred Stock, if applicable)
either upon  consummation  of the  IPC  Direct Merger  (or  the IPC  Merger,  if
applicable)  or, if applicable,  upon the exchange of  their IPC Preferred Stock
for New IPC Preferred Stock pursuant to the IPC Reincorporation Merger; and (iv)
no gain or loss will be recognized  by shareowners of WPLH upon consummation  of
the Mergers. See "The Mergers -- Certain Federal Income Tax Consequences."
 
    EACH  SHAREOWNER IS URGED TO  CONSULT HIS, HER OR ITS  TAX ADVISOR AS TO THE
TAX CONSEQUENCES OF THE  MERGERS APPLICABLE TO  THE INDIVIDUAL CIRCUMSTANCES  OF
SUCH SHAREOWNER UNDER FEDERAL, STATE, LOCAL OR ANY OTHER
APPLICABLE LAW.
 
                                       12
<PAGE>
OPERATIONS AFTER THE MERGERS
 
    Following the Mergers, Interstate Energy will be a registered public utility
holding  company under  the 1935 Act  (unless pending legislation  to repeal the
1935 Act has been enacted), and  the operating utilities WP&L, New Utilities  or
Utilities,  as the case may be, and New IPC  or IPC, as the case may be, will be
its principal subsidiaries.  The headquarters  of Interstate Energy  will be  in
Madison,  Wisconsin.  The headquarters  of the  three utility  subsidiaries will
remain in their current locations, WP&L in Madison, Wisconsin, New Utilities  or
Utilities  in Cedar Rapids, Iowa and New IPC or IPC in Dubuque, Iowa. Interstate
Energy's utility  subsidiaries  are  expected  to  serve  approximately  870,000
electric  customers  and  360,000 natural  gas  customers in  portions  of Iowa,
Illinois, Minnesota and Wisconsin. The business of Interstate Energy will be  to
operate   as  a  holding  company  for  its  utility  subsidiaries  and  various
non-utility subsidiaries. WPLH, IES and IPC recognize that the SEC could require
divestiture of  all  or  part  of their  existing  gas  operations  and  certain
non-utility  operations  under  the registered  holding  company  structure, but
intend to seek approval from the SEC to retain such businesses. See  "Regulatory
Matters" and "Interstate Energy Following the Mergers -- Operations."
 
REGULATORY MATTERS
 
    The  approval  of  the  SEC  under  the  1935  Act,  the  Nuclear Regulatory
Commission (the "NRC")  under the  Atomic Energy Act  of 1954,  as amended  (the
"Atomic  Energy  Act"), the  Federal Energy  Regulatory Commission  (the "FERC")
under the Federal Power Act, as well as the approval of the Iowa Utilities Board
(the "IUB"), the Illinois Commerce Commission (the "ICC"), the Minnesota  Public
Utilities  Commission  (the  "Minnesota  Commission")  and  the  Public  Service
Commission of Wisconsin (the "Wisconsin Commission") under applicable state laws
and the expiration  or termination of  the applicable waiting  period under  the
Hart-Scott-Rodino  Antitrust  Improvements Act  of  1976, as  amended  (the "HSR
Act"), are required in order to consummate the Mergers.
 
    Upon consummation  of the  Mergers, Interstate  Energy will  be required  to
register  as a holding company under the  1935 Act unless pending legislation to
repeal the 1935 Act has been enacted.  The 1935 Act imposes restrictions on  the
operations  of registered holding company  systems. Among these are requirements
that securities issuances, sales and acquisitions of utility assets,  securities
of  utility and  other companies,  and any  other interests  in any  business be
approved by the SEC. The 1935 Act also limits the ability of registered  holding
companies to engage in non-utility ventures and regulates holding company system
service companies and the rendering of services by holding company affiliates to
the system's utilities. WPLH, IES and IPC believe the foregoing restrictions and
limitations  imposed by  the 1935  Act in  its current  form may  limit possible
operations of Interstate Energy  following the Mergers.  However, WPLH, IES  and
IPC  believe the benefits of the Mergers exceed the potential adverse effects of
such 1935 Act regulation.
 
    In addition, the SEC historically has  interpreted the 1935 Act to  preclude
registered holding companies, with limited exceptions, from owning both electric
and  gas  utility  systems.  Although  the  SEC  has  recently  recommended that
registered holding companies be  allowed to hold both  gas and electric  utility
operations  if the affected states  agree, it remains possible  that the SEC may
require as a condition  to its approval  of the Mergers that  WPLH, IES and  IPC
divest  their gas utility  properties and possibly  certain non-utility ventures
within a  reasonable time  after the  Mergers.  In certain  cases, the  SEC  has
allowed the retention of such properties or deferred the question of divestiture
for  a substantial period of time. In those cases in which divestiture has taken
place, the SEC has usually allowed enough time to complete the divestiture so as
to allow the applicant to conduct an orderly sale of the divested assets.  WPLH,
IES  and IPC  believe there  are strong policy  reasons and  prior SEC decisions
which support their retention of existing gas utility properties and non-utility
ventures, or, alternatively, which support deferring the question of divestiture
for a substantial period of time. Accordingly, WPLH, IES and IPC will request in
their 1935 Act application that  WPLH, IES and IPC be  allowed to retain, or  in
the  alternative that the  question of divestiture be  deferred with respect to,
WPLH's,  IES's  and  IPC's  existing  gas  utility  properties  and  non-utility
ventures. Should the SEC
 
                                       13
<PAGE>
deny this request, a required divestiture could, under certain circumstances, be
at  a price below fair market value  or otherwise on terms deemed unsatisfactory
by Interstate Energy and could have a material adverse effect on the operations,
earnings and financial condition of Interstate Energy.
 
    Legislation to repeal the 1935 Act was introduced in Congress in 1995 and is
pending. No assurance can  be given as  to when or if  such legislation will  be
considered  or enacted. The Staff  of the SEC has  also recommended that the SEC
"permit combination  systems by  registered holding  companies if  the  affected
states  concur,"  and  the  SEC  has proposed  rules  that  would  relax current
restrictions on investment  by registered holding  companies in certain  "energy
related," non-utility businesses. No prediction can be made as to the outcome of
these legislative and regulatory proposals.
 
    Following  consummation  of  the  Mergers, Interstate  Energy  also  will be
subject to regulation  by the  Wisconsin Commission under  Section 196.795  Wis.
Stats. (the "Wisconsin Holding Company Act") as WPLH and WP&L are currently. The
Wisconsin Holding Company Act regulates, among other things, the type and amount
of  investments in non-utility businesses. WPLH, IES  and IPC do not expect such
regulation to have a materially adverse effect upon the operations of Interstate
Energy following the  Mergers. WPLH,  IES and IPC  believe, and  intend to  take
appropriate  action  to establish,  that IPC  and  Utilities qualify  as "public
utility affiliates" of  Interstate Energy  within the meaning  of the  Wisconsin
Holding  Company Act. If, however, IPC  and Utilities, as presently constituted,
were to  be  deemed  nonutility  affiliates  (because  they  are  not  Wisconsin
utilities or Wisconsin corporations), the parties reserve the right to take such
action  as may be required  to cause IPC and Utilities  to be treated as "public
utility affiliates" for purposes of the Wisconsin Holding Company Act. Under the
alternative structure set forth in the Merger Agreement, IPC and Utilities would
become  Wisconsin  corporations  and  acquire  certain  of  the  water   utility
operations  currently conducted by WP&L within  the State of Wisconsin. Although
the parties believe  that the Mergers  can be consummated  under either or  both
structures  in compliance with  the Wisconsin Holding  Company Act, that statute
has  not  been   authoritatively  construed,   and  no  assurance   as  to   the
interpretation  of that statute can be  given. The companies currently intend to
seek regulatory  approval to  effect the  transactions under  either  structure.
WPLH,  IES  and  IPC  believe that,  under  the  reincorporation  structure, the
Wisconsin Commission would not seek to regulate activities of New Utilities  and
New  IPC following the  Mergers other than those  activities directly related to
the water utility properties and the  provision of water utility service in  the
State of Wisconsin.
 
    Under  the  Merger Agreement,  WPLH,  IES and  IPC  have agreed  to  use all
reasonable efforts  to  obtain  all  governmental  authorizations  necessary  or
advisable  to consummate or  effect the transactions  contemplated by the Merger
Agreement. Various parties may seek to intervene in these proceedings to  oppose
the  Mergers  or  to  have  conditions imposed  upon  the  receipt  of necessary
approvals. While WPLH, IES and IPC believe that they will receive the  requisite
regulatory approvals for the Mergers, there can be no assurance as to the timing
of  such approvals or  the ability of  such parties to  obtain such approvals on
satisfactory terms or otherwise.  It is a condition  to the consummation of  the
Mergers  that final  orders approving the  Mergers be obtained  from the various
federal and  state commissions  described above  on terms  and conditions  which
would  not have, or would  not be reasonably likely  to have, a material adverse
effect on the business,  assets, financial condition,  results of operations  or
prospects  of Interstate Energy, or which  would be materially inconsistent with
the agreements of the parties contained in the Merger Agreement. There can be no
assurance that any  such approvals  will not  contain terms  or conditions  that
cause  such approvals to fail  to satisfy such condition  to the consummation of
the  Mergers.  Should   any  such   approvals  contain   terms  and   conditions
unsatisfactory  to  WPLH, IES  or IPC,  such  party may  waive the  condition to
consummation of,  and  may  proceed with,  the  Mergers.  Additional  shareowner
approval  for any such  waiver will not  be required or  sought. See "Regulatory
Matters."
 
ACCOUNTING TREATMENT
 
    The Mergers will be  treated by the  parties as a  pooling of interests  for
accounting  purposes. See "The Mergers --  Accounting Treatment." The receipt by
each of WPLH, IES and IPC of a letter from
 
                                       14
<PAGE>
their respective  independent accountants,  stating  that the  transaction  will
qualify  as a pooling of interests, is a condition precedent to the consummation
of the  Mergers.  See  "The  Merger Agreement  --  Conditions  to  Each  Party's
Obligation to Effect the Mergers."
 
DISSENTERS' RIGHTS
 
    Under  Iowa law, holders of record of IES  Common Stock as of the IES Record
Date who do not wish to accept  shares of Interstate Energy Common Stock in  the
IES  Merger have the right to have the fair value of the IES shares appraised by
judicial determination  and paid  to them  in  cash. In  order to  perfect  such
dissenters'  rights, holders of IES Common Stock must comply with the procedural
requirements of the IBCA, including,  without limitation, filing written  notice
with IES prior to the IES Meeting of such shareholder's intention to dissent and
demand  payment of the fair value  of his or her shares,  not voting in favor of
the Merger Agreement and making a written demand for payment and depositing  the
certificates  representing such shares  within 30 days after  notice is given by
IES of the  results of the  vote at the  IES Meeting. See  "The Mergers --  Iowa
Dissenters' Rights" and Annex P.
 
    Under  Delaware law, holders of record of  IPC Preferred Stock as of the IPC
Record Date who  wish to  exercise dissenters' rights  with respect  to the  IPC
Direct  Merger or who do not  wish to accept New IPC  Preferred Stock in the IPC
Reincorporation Merger, as  the case may  be, have  the right to  have the  fair
value of their shares of IPC Preferred Stock appraised by judicial determination
and  paid to them. In  order to perfect such  dissenters' rights, holders of IPC
Preferred Stock  must  comply with  the  procedural requirements  of  the  DGCL,
including,  without  limitation,  delivering to  IPC  before the  IPC  Meeting a
written notice of such stockholder's  intention to dissent and demand  appraisal
of  his or her shares, not voting in  favor of the Merger Agreement and filing a
petition in  the Delaware  Court  of Chancery  (the "Delaware  Chancery  Court")
demanding  a determination of the  fair value of the  IPC Preferred Stock. Under
Delaware law, the  holders of  IPC Common Stock  have no  dissenters' rights  in
connection  with the Mergers.  See "The Mergers  -- Delaware Dissenters' Rights"
and Annex Q.
 
    Under Wisconsin law, the  holders of WPLH Common  Stock have no  dissenters'
rights. See "The Mergers -- No Wisconsin Dissenters' Rights."
 
DIVIDENDS
 
    WPLH,  IES AND  IPC PRIOR  TO THE  EFFECTIVE TIME.   Pursuant  to the Merger
Agreement, each of WPLH, IES and IPC shall not, and shall not permit any of  its
subsidiaries to, declare or pay any dividends on, or make other distributions in
respect  of,  any  of  its  capital  stock, other  than  to  such  party  or its
wholly-owned subsidiaries and other  than dividends required to  be paid on  any
series  of  cumulative preferred  stock, no  par value,  of IES  ("IES Preferred
Stock") (no  shares of  which are  currently outstanding),  Utilities  Preferred
Stock,  preferred stock, no par value, of  WP&L ("WP&L Preferred Stock"), or IPC
Preferred Stock in  accordance with  the respective terms  thereof, and  regular
quarterly  dividends to be paid  on WPLH Common Stock,  IES Common Stock and IPC
Common Stock not  to exceed in  any fiscal year  100% of the  dividends for  the
prior fiscal year in the case of IES and IPC and 105% in the case of WPLH.
 
    INTERSTATE  ENERGY  AFTER  THE  EFFECTIVE  TIME.    IT  IS  ANTICIPATED THAT
INTERSTATE ENERGY WILL RETAIN WPLH'S THEN CURRENT COMMON SHARE DIVIDEND  PAYMENT
LEVEL AS OF THE EFFECTIVE TIME. WPLH's current annualized dividend rate is $1.97
per  share, IES's annual  dividend rate is  currently $2.10 per  share and IPC's
annual dividend  rate is  currently  $2.08 per  share.  The dividend  policy  of
Interstate  Energy is subject to evaluation from  time to time by the Interstate
Energy Board  based  on Interstate  Energy's  results of  operations,  financial
condition,  capital  requirements and  other relevant  considerations, including
regulatory considerations.  Declaration and  timing of  dividends on  Interstate
Energy  Common Stock will  be a business  decision to be  made by the Interstate
Energy Board  from  time  to time  based  upon  the results  of  operations  and
financial  condition of  Interstate Energy and  its subsidiaries  and such other
business considerations as  the Interstate  Energy Board  considers relevant  in
accordance  with applicable laws. See  "Interstate Energy Following the Mergers"
and "Description of Interstate Energy Capital Stock -- Interstate Energy  Common
Stock."
 
                                       15
<PAGE>
    PREFERRED  STOCK AFTER  THE EFFECTIVE TIME.   Following  the Effective Time,
dividends will be paid on shares of IES Preferred Stock (if any such shares  are
then outstanding), Utilities Preferred Stock (unless such shares are redeemed in
connection  with the Utilities Reincorporation Merger), WP&L Preferred Stock and
IPC Preferred  Stock (or  New IPC  Preferred Stock  if the  IPC  Reincorporation
Merger is effected) in accordance with the respective terms of such stock.
 
AMENDMENTS TO WPLH CHARTER
 
    Pursuant  to the Merger  Agreement, subject to  the approval of  each of the
WPLH Charter Amendments  by WPLH's  shareowners at  the WPLH  Meeting, the  WPLH
Charter will be amended no later than the Effective Time as provided in Annex O.
The  WPLH Charter  Amendments will  (i) change  the name  of WPLH  to Interstate
Energy Corporation; and (ii) increase the number of shares of WPLH Common  Stock
authorized for issuance from 100,000,000 to 200,000,000. The WPLH Charter, as so
amended,  will be  the Restated Articles  of Incorporation  of Interstate Energy
(the "Interstate Energy  Charter") at  the Effective Time  and until  thereafter
amended  in accordance with the WBCL and the Interstate Energy Charter. Approval
of each  of  the  WPLH  Charter  Amendments is  a  condition  precedent  to  the
consummation  of  the  Mergers. See  "Amendments  to WPLH  Restated  Articles of
Incorporation."
 
AMENDMENT TO IPC CHARTER
 
    Subject to the approval of the  IPC Charter Amendment by IPC's  stockholders
at  the IPC Meeting, the  IPC Charter will be  amended following the IPC Meeting
and prior  to  the Effective  Time  as provided  in  Annex R.  The  IPC  Charter
Amendment  would provide that each share of IPC Preferred Stock outstanding from
time to time will have one vote,  voting together as one class with the  holders
of  IPC  Common Stock  (except as  otherwise  required by  applicable law  or as
specifically set forth in the IPC Charter), on all matters to come before a vote
of the stockholders of IPC. The IPC Charter Amendment is designed to comply with
certain provisions of the Code to enable the IPC Merger to qualify as a tax-free
reorganization under  the Code.  Approval  of the  IPC  Charter Amendment  is  a
condition  precedent to the  consummation of the Mergers.  See "Amendment to IPC
Restated Certificate  of  Incorporation" and  "The  Mergers --  Certain  Federal
Income Tax Consequences."
 
COMPARISON OF RIGHTS OF SHAREOWNERS
 
    As  a result  of the Mergers,  holders of  IES Common Stock  (other than IES
Dissenting Shares) will  become shareowners  of Interstate  Energy, a  Wisconsin
corporation.  Such shareowners will have  certain different rights as Interstate
Energy shareowners than  they had  as shareowners of  IES, both  because of  the
differences between the IES Charter and the IES Bylaws and the Interstate Energy
Charter  and the bylaws  of Interstate Energy  (the "Interstate Energy Bylaws"),
and because of  differences between Wisconsin  and Iowa corporation  law. For  a
comparison of Wisconsin and Iowa law and the charter and bylaw provisions of IES
and Interstate Energy, see "Comparison of Shareowner Rights."
 
    As  a  result  of the  Mergers,  holders  of IPC  Common  Stock  will become
shareowners of Interstate Energy, a Wisconsin corporation. Such shareowners will
have certain different rights as Interstate Energy shareowners than they had  as
shareowners  of IPC, both because of the differences between the IPC Charter and
the IPC  Bylaws and  the Interstate  Energy Charter  and the  Interstate  Energy
Bylaws,  and because of  differences between Wisconsin  and Delaware corporation
law. In the event  that the IPC Reincorporation  Merger is effected, holders  of
IPC  Preferred Stock (other than IPC Dissenting  Shares) will receive in the IPC
Reincorporation Merger shares of New  IPC Preferred Stock, the terms  (including
dividend  rates) and  designations of which  will be  substantially identical to
those of the corresponding shares  of IPC Preferred Stock  (as set forth in  the
IPC  Charter), including the additional voting rights proposed to be approved at
the IPC  Meeting. The  rights  of holders  of New  IPC  Preferred Stock  may  be
different  in certain respects under Wisconsin law than the rights of holders of
IPC Preferred  Stock under  Delaware  law. For  a  comparison of  Wisconsin  and
Delaware  law and the charter and bylaw provisions of IPC and Interstate Energy,
see "Comparison of Shareowner Rights."
 
                                       16
<PAGE>
                     SELECTED HISTORICAL AND PRO FORMA DATA
 
    The summary below sets forth  selected historical financial and market  data
and  selected unaudited pro  forma financial data. The  financial data should be
read in conjunction  with the historical  consolidated financial statements  and
related  notes thereto of  WPLH, IES and IPC,  incorporated herein by reference,
and in conjunction with  the unaudited pro  forma combined financial  statements
and  related notes thereto of Interstate Energy included elsewhere in this Joint
Proxy  Statement/Prospectus.  See  "Unaudited   Pro  Forma  Combined   Financial
Information."
 
SELECTED HISTORICAL FINANCIAL AND MARKET DATA
 
    The  selected historical financial data of each of WPLH, IES and IPC for the
five years ended December 31, 1995,  set forth below, have been derived  (except
as  described below) from audited  financial statements. The selected historical
financial data of WPLH, IES and IPC as of and for the twelve-month period  ended
March  31, 1996, set forth below, have  been derived (except as described below)
from unaudited financial statements. The financial data of WPLH set forth  below
have  been  adjusted to  reflect the  restatement  of such  data to  account for
certain discontinued  operations discussed  in the  notes hereto.  The  selected
historical  market data  of each of  WPLH, IES  and IPC for  the dates indicated
below are based on  the closing sales  prices of WPLH  Common Stock, IES  Common
Stock  and IPC  Common Stock  as reported  on the  NYSE Composite  Tape for such
dates. The Aggregate Market Capitalization represents the product of the closing
sale prices on such dates multiplied by the number of outstanding shares on such
dates.
 
                                       17
<PAGE>
                               WPL HOLDINGS, INC.
 
<TABLE>
<CAPTION>
                                TWELVE MONTHS                          YEAR ENDED DECEMBER 31,
                                 ENDED MARCH    ---------------------------------------------------------------------
                                   31, 1996         1995          1994          1993          1992          1991
                                --------------  ------------  ------------  ------------  ------------  -------------
                                               (DOLLARS IN THOUSANDS EXCEPT PER SHARE AND RATIO DATA)
<S>                             <C>             <C>           <C>           <C>           <C>           <C>
INCOME STATEMENT DATA
  Operating Revenues..........   $    852,258   $    807,255  $    795,717  $    738,604  $    673,273  $    669,549
  Operating Income............        158,865        149,404       131,815       127,944       117,959       132,605
  Allowance for Borrowed and
   Other Funds Used During
   Construction...............          2,503          2,088         4,038         4,031         3,680         1,959
  Preferred Dividend
   Requirements of
   Subsidiary.................          3,310          3,310         3,310         3,928         3,811         3,811
  Income From Continuing
   Operations (a)(g)(j).......         83,239         71,618        66,424        63,685        58,007        65,930
  Earnings per Common Share
   from Continuing Operations
   (a)(g)(j)..................   $       2.70   $       2.33  $       2.17  $       2.15  $       2.10  $       2.42
  Cash Dividends Declared per
   Common Share...............   $      1.948   $       1.94  $       1.92  $       1.90  $       1.86  $       1.80
</TABLE>
 
<TABLE>
<CAPTION>
                                                                            DECEMBER 31,
                                                ---------------------------------------------------------------------
                                MARCH 31, 1996      1995          1994          1993          1992          1991
                                --------------  ------------  ------------  ------------  ------------  -------------
                                               (DOLLARS IN THOUSANDS EXCEPT PER SHARE AND RATIO DATA)
<S>                             <C>             <C>           <C>           <C>           <C>           <C>
BALANCE SHEET DATA
  Total Assets (j)............   $  1,838,674   $  1,872,414  $  1,805,901  $  1,761,899  $  1,565,898  $  1,383,499
  Long-Term Obligations (c)...        429,753        433,759       450,942       425,887       418,960       371,904
  Commercial Paper, Notes
   Payable and Other..........         57,896        109,525        64,501        91,902        71,427        52,838
  Variable Rate Demand
   Bonds......................         56,975         56,975        56,975        56,975        57,075        57,875
  Preferred Stock --
    Not Subject to Mandatory
     Redemption...............         59,963         59,963        59,963        59,963        62,449        62,449
    Subject to Mandatory
     Redemption...............        --             --            --            --            --            --
  Common Stock Equity (j).....        613,628        597,470       597,798       582,966       483,536       459,659
  Book Value per Common Share
   (j)........................   $      19.94   $      19.41  $      19.43  $      19.15  $      17.38  $      16.84
</TABLE>
 
<TABLE>
<CAPTION>
                                                                            DECEMBER 31,
                                                ---------------------------------------------------------------------
                                MARCH 31, 1996      1995          1994          1993          1992          1991
                                --------------  ------------  ------------  ------------  ------------  -------------
<S>                             <C>             <C>           <C>           <C>           <C>           <C>
MARKET DATA -- COMMON STOCK
  Aggregate Market
   Capitalization (millions)..   $        950   $        942  $        842  $      1,001  $        943  $        894
  Closing Market Price per
   Share......................   $     30.875   $     30.625  $     27.375  $     32.875  $     33.875  $      32.75
  Ratio of Market Value to
   Book Value (j).............           1.55x          1.58x         1.41x         1.72x         1.95x         1.94x
</TABLE>
 
        See accompanying Notes to Selected Historical and Pro Forma Data
 
                                       18
<PAGE>
                              IES INDUSTRIES INC.
 
<TABLE>
<CAPTION>
                                TWELVE MONTHS                          YEAR ENDED DECEMBER 31,
                                 ENDED MARCH    ---------------------------------------------------------------------
                                   31, 1996         1995          1994          1993          1992          1991
                                --------------  ------------  ------------  ------------  ------------  -------------
                                               (DOLLARS IN THOUSANDS EXCEPT PER SHARE AND RATIO DATA)
<S>                             <C>             <C>           <C>           <C>           <C>           <C>
INCOME STATEMENT DATA
  Operating Revenues..........   $    887,816   $    851,010  $    785,864  $    801,266  $    678,296  $    661,538
  Operating Income............        166,594        151,712       147,933       151,269       109,024       103,357
  Allowance for Borrowed and
   Other Funds Used During
   Construction...............          2,999          3,424         3,910         1,972         3,177         2,086
  Preferred and Preference
   Dividend Requirements of
   Subsidiary.................            914            914           914           914         1,729         2,170
  Income from Continuing
   Operations (a)(i)..........         71,531         64,176        66,818        67,938        48,711        44,657
  Earnings per Common Share
   from Continuing Operations
   (a)(i).....................   $       2.43   $       2.20  $       2.34  $       2.45  $       1.92  $       1.85
  Cash Dividends Declared per
   Common Share...............   $       2.10   $       2.10  $       2.10  $       2.10  $       2.10  $       2.03
</TABLE>
 
<TABLE>
<CAPTION>
                                                                            DECEMBER 31,
                                                ---------------------------------------------------------------------
                                MARCH 31, 1996      1995          1994          1993          1992          1991
                                --------------  ------------  ------------  ------------  ------------  -------------
                                               (DOLLARS IN THOUSANDS EXCEPT PER SHARE AND RATIO DATA)
<S>                             <C>             <C>           <C>           <C>           <C>           <C>
BALANCE SHEET DATA
  Total Assets................   $  1,986,944   $  1,985,591  $  1,849,093  $  1,699,819  $  1,594,382  $  1,448,492
  Long-Term Obligations (c)...        653,450        656,543       626,011       577,611       553,257       507,921
  Commercial Paper, Notes
   Payable and Other..........         92,000        101,000        37,000        24,000        92,000        40,900
  Preferred and Preference
   Stock --
    Not Subject to Mandatory
     Redemption...............         18,320         18,320        18,320        18,320        18,320        18,320
    Subject to Mandatory
     Redemption...............        --             --            --            --            --             10,874
  Common Stock Equity.........        615,820        612,346       591,783       572,051       482,729       463,296
  Book Value per Common
   Share......................   $      20.75   $      20.75  $      20.56  $      20.21  $      18.89  $      19.07
</TABLE>
 
<TABLE>
<CAPTION>
                                                                            DECEMBER 31,
                                                ---------------------------------------------------------------------
                                MARCH 31, 1996      1995          1994          1993          1992          1991
                                --------------  ------------  ------------  ------------  ------------  -------------
<S>                             <C>             <C>           <C>           <C>           <C>           <C>
MARKET DATA -- COMMON STOCK
  Aggregate Market
   Capitalization (millions)..   $        827   $        782  $        727  $        885  $        754  $        662
  Closing Market Price per
   Share......................   $     27.875   $      26.50  $      25.25  $      31.25  $      29.50  $      27.25
  Ratio of Market Value to
   Book Value.................           1.34x          1.28x         1.23x         1.55x         1.56x         1.43x
</TABLE>
 
        See accompanying Notes to Selected Historical and Pro Forma Data
 
                                       19
<PAGE>
                         INTERSTATE POWER COMPANY (IPC)
 
<TABLE>
<CAPTION>
                                         TWELVE MONTHS                     YEAR ENDED DECEMBER 31,
                                          ENDED MARCH    -----------------------------------------------------------
                                            31, 1996        1995        1994        1993        1992        1991
                                         --------------  ----------  ----------  ----------  ----------  -----------
                                                   (DOLLARS IN THOUSANDS EXCEPT PER SHARE AND RATIO DATA)
<S>                                      <C>             <C>         <C>         <C>         <C>         <C>
INCOME STATEMENT DATA
  Operating Revenues...................    $  322,826    $  318,542  $  307,650  $  309,468  $  285,298  $  291,805
  Operating Income (h).................        69,190        66,776      43,435      43,791      44,521      60,911
  Allowance for Borrowed and Other
   Funds Used During Construction......           304           341         498         213         371       2,094
  Preferred and Preference Dividend
   Requirements........................         2,459         2,458       2,454       2,861       2,975       3,075
  Income from Continuing Operations
   (h).................................        26,982        25,198      18,213      16,126      16,242      26,435
  Earnings per Common Share from
   Continuing Operations (h)...........    $     2.82    $     2.63  $     1.92  $     1.73  $     1.74  $     2.84
  Cash Dividends Declared per Common
   Share...............................    $     2.08    $     2.08  $     2.08  $     2.08  $     2.08  $     2.04
  Ratio of Earnings to Fixed Charges
   Plus Preferred and Preference
   Dividend Requirements (b)...........          3.15x         2.99x       2.26x       2.14x       2.13x       2.92x
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                DECEMBER 31,
                                                         -----------------------------------------------------------
                                         MARCH 31, 1996     1995        1994        1993        1992        1991
                                         --------------  ----------  ----------  ----------  ----------  -----------
                                                   (DOLLARS IN THOUSANDS EXCEPT PER SHARE AND RATIO DATA)
<S>                                      <C>             <C>         <C>         <C>         <C>         <C>
BALANCE SHEET DATA
  Total Assets.........................    $  630,107    $  634,316  $  628,845  $  604,361  $  558,100  $  550,631
  Long-Term Obligations (c)............       188,899       188,880     203,032     203,170     199,532     205,036
  Commercial Paper, Notes Payable and
   Other...............................        23,150        39,300      35,600      20,100       9,000       7,200
  Preferred and Preference Stock --
    Not Subject to Mandatory
     Redemption........................        10,819        10,819      10,819      10,819      20,911      20,911
    Subject to Mandatory Redemption....        24,062        24,036      23,933      23,837      14,426      15,782
  Common Stock Equity..................       201,713       197,770     192,505     189,809     190,324     193,421
  Book Value per Common Share..........    $    21.09    $    20.68  $    20.13  $    20.21  $    20.47  $    20.80
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                DECEMBER 31,
                                                         -----------------------------------------------------------
                                         MARCH 31, 1996     1995        1994        1993        1992        1991
                                         --------------  ----------  ----------  ----------  ----------  -----------
<S>                                      <C>             <C>         <C>         <C>         <C>         <C>
MARKET DATA -- COMMON STOCK
  Aggregate Market Capitalization
   (millions)..........................    $      305    $      317  $      227  $      283  $      287  $      314
  Closing Market Price per Share.......    $   31.875    $   33.125  $    23.75  $   30.125  $   30.875  $    33.75
  Ratio of Market Value to Book
   Value...............................          1.51x         1.60x       1.18x       1.49x       1.51x       1.62x
</TABLE>
 
        See accompanying Notes to Selected Historical and Pro Forma Data
 
                                       20
<PAGE>
SELECTED UNAUDITED PRO FORMA FINANCIAL DATA
 
    The  following selected  unaudited pro forma  financial information combines
the historical consolidated balance sheets and statements of income of WPLH, IES
and IPC, including  their respective  subsidiaries, after giving  effect to  the
Mergers.  The unaudited pro forma combined balance  sheet data at March 31, 1996
and December 31, 1995, 1994 and 1993 give  effect to the Mergers as if they  had
occurred at the respective balance sheet dates. The unaudited pro forma combined
statements  of income for the twelve months ended March 31, 1996 and each of the
years in  the three-year  period ended  December  31, 1995  give effect  to  the
Mergers  as  if they  had  occurred at  January  1, 1993.  These  statements are
prepared on the basis of  accounting for the Mergers  as a pooling of  interests
and  are based on the assumptions set  forth in the notes thereto. The following
information is not necessarily indicative of the financial position or operating
results that would have occurred had the Mergers been consummated on the date as
of which, or at the  beginning of the periods for  which, the Mergers are  being
given  effect nor  is it necessarily  indicative of future  operating results or
financial position. See "Unaudited Pro Forma Combined Financial Information."
 
             INTERSTATE ENERGY CORPORATION PRO FORMA FINANCIAL DATA
 
<TABLE>
<CAPTION>
                                                                          TWELVE MONTHS       YEAR ENDED DECEMBER 31,
                                                                              ENDED       -------------------------------
                                                                         MARCH 31, 1996     1995       1994       1993
                                                                         ---------------  ---------  ---------  ---------
                                                                           (DOLLARS IN MILLIONS, EXCEPT PER SHARE DATA)
<S>                                                                      <C>              <C>        <C>        <C>
INCOME STATEMENT DATA
  Operating Revenues...................................................     $   2,063     $   1,977  $   1,889  $   1,849
  Operating Income.....................................................           395           368        323        323
  Allowance for Borrowed and Other Funds Used During Construction......             6             6          8          6
  Preferred Dividend Requirements of Subsidiaries......................             7             7          7          8
  Income from Continuing Operations (a)(g)(h)(i)(j)....................           182           161        151        148
  Earnings Per Common Share from Continuing
   Operations (a)(d)(g)(h)(i)(j).......................................     $    2.56     $    2.27  $    2.16  $    2.17
  Cash Dividends Declared per Common Share (d).........................     $    1.99     $    1.99  $    1.98  $    1.97
EQUIVALENT IES PRO FORMA PER SHARE DATA (E)
  Earnings per Common Share (a)(g)(h)(i)...............................     $    2.59     $    2.29  $    2.18  $    2.19
  Cash Dividends Declared per Common Share (f).........................     $    2.01     $    2.01  $    2.00  $    1.99
EQUIVALENT IPC PRO FORMA PER SHARE DATA (E)
  Earnings per Common Share (a)(g)(h)(i)...............................     $    2.84     $    2.52  $    2.40  $    2.41
  Cash Dividends Declared per Common Share(f)..........................     $    2.21     $    2.21  $    2.20  $    2.19
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                                   DECEMBER 31,
                                                                            MARCH 31,     -------------------------------
                                                                              1996          1995       1994       1993
                                                                         ---------------  ---------  ---------  ---------
                                                                           (DOLLARS IN MILLIONS, EXCEPT PER SHARE DATA)
<S>                                                                      <C>              <C>        <C>        <C>
BALANCE SHEET DATA
  Total Assets (j).....................................................     $   4,456     $   4,492  $   4,284  $   4,066
  Long-Term Obligations (c)............................................         1,270         1,279      1,280      1,207
  Variable Rate Demand Bonds...........................................            57            57         57         57
  Commercial Paper, Notes and Other....................................           173           250        137        136
  Preferred Stock --
    Not Subject to Mandatory Redemption................................            89            89         89         89
    Subject to Mandatory Redemption....................................            24            24         24         24
  Common Stock Equity (j)..............................................         1,423         1,399      1,382      1,345
  Book Value per Common Share (j)......................................     $   19.94     $   19.65     --         --
EQUIVALENT IES PRO FORMA PER SHARE DATA (E)
  Book Value per Common Share (j)......................................     $   20.14     $   19.85     --         --
EQUIVALENT IPC PRO FORMA PER SHARE DATA (E)
  Book Value per Common Share Data (j).................................     $   22.13     $   21.81     --         --
</TABLE>
 
        See accompanying Notes to Selected Historical and Pro Forma Data
 
                                       21
<PAGE>
COMPARATIVE BOOK VALUES, DIVIDENDS AND EARNINGS PER COMMON SHARE
 
<TABLE>
<CAPTION>
                                                                                        MARCH 31,     DECEMBER 31,
                                                                                          1996            1995
                                                                                     ---------------  -------------
<S>                                                                                  <C>              <C>
BOOK VALUES PER COMMON SHARE
  WPLH/Interstate Energy
    Historical (j).................................................................     $   19.94       $   19.41
    Equivalent pro forma (j).......................................................     $   19.94       $   19.65
  IES
    Historical.....................................................................     $   20.75       $   20.75
    Equivalent pro forma (e)(j)....................................................     $   20.14       $   19.85
  IPC
    Historical.....................................................................     $   21.09       $   20.68
    Equivalent pro forma (e)(j)....................................................     $   22.13       $   21.81
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                                 YEAR ENDED DECEMBER 31,
                                                                             TWELVE MONTHS
                                                                                 ENDED       -------------------------------
                                                                            MARCH 31, 1996     1995       1994       1993
                                                                            ---------------  ---------  ---------  ---------
<S>                                                                         <C>              <C>        <C>        <C>
CASH DIVIDENDS DECLARED PER COMMON SHARE
  WPLH/Interstate Energy
    Historical............................................................     $   1.948     $    1.94  $    1.92  $    1.90
    Equivalent pro forma (d)..............................................     $    1.99     $    1.99  $    1.98  $    1.97
  IES
    Historical............................................................     $    2.10     $    2.10  $    2.10  $    2.10
    Equivalent pro forma (e)(f)...........................................     $    2.01     $    2.01  $    2.00  $    1.99
  IPC
    Historical............................................................     $    2.08     $    2.08  $    2.08  $    2.08
    Equivalent pro forma (e)(f)...........................................     $    2.21     $    2.21  $    2.20  $    2.19
EARNINGS PER COMMON SHARE FROM CONTINUING OPERATIONS
  WPLH/Interstate Energy
    Historical (a)(g)(j)..................................................     $    2.70     $    2.33  $    2.17  $    2.15
    Equivalent pro forma (a)(d)(g)(h)(j)..................................     $    2.56     $    2.27  $    2.16  $    2.17
  IES
    Historical (a)(i).....................................................     $    2.43     $    2.20  $    2.34  $    2.45
    Equivalent pro forma (a)(e)(g)(h)(i)..................................     $    2.59     $    2.29  $    2.18  $    2.19
  IPC
    Historical (h)........................................................     $    2.82     $    2.63  $    1.92  $    1.73
    Equivalent pro forma (a)(e)(g)(h)(i)..................................     $    2.84     $    2.52  $    2.40  $    2.41
</TABLE>
 
        See accompanying Notes to Selected Historical and Pro Forma Data
 
                                       22
<PAGE>
NOTES TO SELECTED HISTORICAL AND PRO FORMA DATA
 
(a) Income from Continuing Operations and Earnings per Common Share are based on
    income from continuing operations after preferred dividend requirements.
 
(b) For  purposes of  computing the  ratios of  earnings to  fixed charges  plus
    preferred and preference dividend requirements, "earnings" consist of income
    from  continuing  operations before  accounting changes  (see Note  k), plus
    interest charges,  preferred and  preference dividend  requirements,  income
    taxes,   and  the  estimated  interest   component  of  rentals,  minus  the
    undistributed equity  in earnings  of unconsolidated  investees.  "Earnings"
    also   include  allowance   for  borrowed   and  other   funds  used  during
    construction. "Fixed  charges" consist  of interest  charges, the  estimated
    interest  component  of rentals  and  the pre-tax  dividend  requirements on
    subsidiary preferred stock. Currently, the IPC Preferred Stock is not issued
    by a subsidiary; subsequent to the  Mergers, the IPC Preferred Stock or  the
    New  IPC Preferred Stock, as the case may be, will be issued by a subsidiary
    of Interstate Energy. The pro forma ratios of earnings to fixed charges plus
    preferred and  preference dividend  requirements of  New IPC  (after  giving
    effect  to the IPC Reincorporation Merger)  for the years ended December 31,
    1993, 1994 and 1995 and for the twelve months ended March 31, 1996 are 2.14,
    2.26, 2.99 and 3.15, respectively.
 
(c) Includes  long-term debt,  sinking  fund requirements,  current  maturities,
    current and long-term capital lease obligations, net of unamortized discount
    and premium.
 
(d)  Pro forma per  common share amounts  give effect to  the conversion of each
    share of IES  Common Stock and  IPC Common Stock  outstanding into 1.01  and
    1.11  shares, respectively, of Interstate Energy Common Stock. Pro forma per
    common share  amounts  do  not,  however, give  effect  to  the  cost-saving
    synergies  of the transaction or transaction costs. For a description of the
    synergies, see "The Mergers --  Reasons for the Mergers; Recommendations  of
    the Boards of Directors."
 
(e)  Represents the pro forma equivalent of one share of IES Common Stock or one
    share of IPC Common Stock, as the case may be, calculated by multiplying the
    pro forma  information by  the conversion  ratio of  1.01 and  1.11  shares,
    respectively, of Interstate Energy Common Stock for each share of IES Common
    Stock and IPC Common Stock.
 
(f)  Pursuant to SEC requirements, the  amount is calculated based on historical
    dividends paid  by WPLH,  IES,  and IPC  combined.  It is  anticipated  that
    Interstate  Energy will retain WPLH's common share dividend payment level in
    effect at the Effective Time.
 
(g) Nonrecurring items affecting WPLH's  1994 performance include the impact  of
    early  retirement and severance programs and the reversal of a coal contract
    penalty assessed by the Wisconsin Commission which was charged to income  in
    1989.  The net  after-tax impact  of these  items on  income from continuing
    operations for  the year  ended December  31, 1994  was a  decrease of  $8.3
    million  related to the early retirement and severance programs offset by an
    increase of $4.9 million related to the coal contract penalty reversal.
 
(h) IPC's income  from continuing operations  includes expenses associated  with
    environmental investigation and remediation costs of former manufactured gas
    plants.  Operating expenses for  the twelve months ended  March 31, 1996 and
    for the years ended December 31,  1995, 1994 and 1993 include $0.2  million,
    $0.3  million, $0.8 million and $3.5 million, respectively, for these costs.
    Other operating expenses for the twelve months ended March 31, 1996 and  for
    the year ended December 31, 1995 also include $0.8 million and $0.7 million,
    respectively,  of legal fees related to  coal tar remediation, compared with
    $1.0 million and  $0.3 million  for the years  ended December  31, 1994  and
    1993,  respectively. For the twelve months ended  March 31, 1996 and for the
    years ended December 31,  1995, 1994 and 1993,  $0.4 million, $0.6  million,
    $0.7  million and $0.6 million, respectively, of the foregoing expenses were
    recovered in rates.
 
(i) Nonrecurring items affecting IES's income from continuing operations for the
    year ended December  31, 1993 include  various gains and  losses related  to
    sales of assets and property valuation
 
                                       23
<PAGE>
    adjustments  associated with its nonregulated  businesses. The net after-tax
    impact of these  items on  income from  continuing operations  for the  year
    ended December 31, 1993 was a decrease of $2.0 million.
 
(j)     The  selected  historical  and  pro  forma  data  of  WPLH  reflect  the
    discontinuance of operations of its utility energy and marketing  consulting
    business  in 1995. The discontinuance of this business resulted in a pre-tax
    loss of  $7.7  million ($11.0  million  net  of the  applicable  income  tax
    expenses)  in 1995. Operating revenues, operating expenses, other income and
    expense and  income  taxes for  the  discontinued operations  for  the  time
    periods presented have been excluded from income from continuing operations.
    Interest  expense has been  adjusted for the  amounts associated with direct
    obligations of the discontinued operations.
 
    Operating revenues, related losses, and income tax benefits associated  with
    the discontinued operations for the indicated time periods were as follows:
 
<TABLE>
<CAPTION>
                                                       TWELVE
                                                       MONTHS
                                                     ENDED MARCH      YEAR ENDED DECEMBER 31,
                                                         31,      -------------------------------
                                                        1996        1995       1994       1993
                                                     -----------  ---------  ---------  ---------
                                                                (DOLLARS IN THOUSANDS)
<S>                                                  <C>          <C>        <C>        <C>
Operating revenues.................................   $  15,969   $  24,979  $  34,798  $  33,340
                                                     -----------  ---------  ---------  ---------
                                                     -----------  ---------  ---------  ---------
Loss from discontinued operations before tax
 benefit...........................................   $   2,990   $   3,663  $   1,806  $   1,761
Income tax benefit.................................       1,184       1,451        632        599
                                                     -----------  ---------  ---------  ---------
Loss from discontinued operations..................   $   1,806   $   2,212  $   1,174  $   1,162
                                                     -----------  ---------  ---------  ---------
                                                     -----------  ---------  ---------  ---------
</TABLE>
 
(k)  Accounting  principles  have  been consistently  applied  in  the financial
    statement presentations for WPLH, IES and  IPC with one exception. IPC  does
    not  include unbilled electric and gas  revenues in its calculation of total
    revenues. The utility subsidiaries of WPLH and IES accrue unbilled revenues.
    The impact of this difference  in accounting principles among the  companies
    does  not have a  material impact on  the selected historical  and pro forma
    data as presented and, accordingly, no adjustments have been made to conform
    accounting principles.
 
COMPARATIVE MARKET PRICES AND DIVIDENDS
 
    The WPLH Common Stock,  the IES Common  Stock and the  IPC Common Stock  are
listed  on the  NYSE, the CSE  and the  PSE; the WPLH  Common Stock  and the IES
Common Stock are also listed on the BSE; and the IES Common Stock is also traded
on the PhSE. The following table sets forth, for the periods indicated, the high
and low sales prices of WPLH Common Stock, IES Common Stock and IPC Common Stock
as reported on the NYSE Composite Tape and the dividends declared thereon.
 
<TABLE>
<CAPTION>
                                 IES                             IPC                             WPLH
                     ----------------------------    ----------------------------    ----------------------------
                      HIGH        LOW   DIVIDENDS     HIGH        LOW   DIVIDENDS     HIGH        LOW   DIVIDENDS
                     -------    ------- ---------    -------    ------- ---------    -------    ------- ---------
<S>                  <C>        <C>     <C>          <C>        <C>     <C>          <C>        <C>     <C>
1993
  First Quarter.....  31 1/8     28 3/8   .525        34 1/8     30 3/8    .52        36         32 1/2    .475
  Second Quarter....  32 5/8     28 5/8   .525        32 3/4     29        .52        36 3/4     33 1/8    .475
  Third Quarter.....  34 1/4     31 1/4   .525        31 3/4     29        .52        36 1/4     35        .475
  Fourth Quarter....  34         29 1/8   .525        30 3/4     29 1/8    .52        36         31 1/2    .475
1994
  First Quarter.....  31 3/8     27       .525        30 1/4     26 3/8    .52        32 7/8     27 3/4     .48
  Second Quarter....  29         25 1/2   .525        29         22 1/4    .52        30 3/4     26 3/8     .48
  Third Quarter.....  28 3/8     24 7/8   .525        24 3/4     21        .52        29 7/8     27         .48
  Fourth Quarter....  26 5/8     24 3/4   .525        23 3/4     20 7/8    .52        28 7/8     26 7/8     .48
</TABLE>
 
                                       24
<PAGE>
 
<TABLE>
<CAPTION>
                                 IES                             IPC                             WPLH
                     ----------------------------    ----------------------------    ----------------------------
                      HIGH        LOW   DIVIDENDS     HIGH        LOW   DIVIDENDS     HIGH        LOW   DIVIDENDS
                     -------    ------- ---------    -------    ------- ---------    -------    ------- ---------
1995
<S>                  <C>        <C>     <C>          <C>        <C>     <C>          <C>        <C>     <C>
  First Quarter.....  27 5/8     24 5/8   .525        25 1/8     23        .52        31         27 1/4    .485
  Second Quarter....  26 3/8     20 3/8   .525        25         23 1/2    .52        30         27 1/2    .485
  Third Quarter.....  26 3/4     21 3/8   .525        27 1/4     23 1/4    .52        29 3/8     27 1/2    .485
  Fourth Quarter....  28 1/2     25 7/8   .525        33 1/4     27 1/8    .52        31 3/4     29 1/4    .485
1996
  First Quarter.....  29 5/8     26 1/2   .525        33 1/2     30        .52        32         29 7/8   .4925
  Second Quarter....  30 1/8     25 1/2   .525        32 1/2     29 7/8    .52        32 7/8     28 5/8   .4925
  Third Quarter ....  30         29 1/4   .525        32 1/8     30 5/8    .52        32 7/8     31 5/8   .4925
   (through July 9)
</TABLE>
 
    On  November  10,  1995,  the  last  full  trading  day  before  the  public
announcement  of the execution  and delivery of the  Merger Agreement, the high,
low and closing sales prices per share of (i) WPLH Common Stock on the NYSE were
$30 7/8, $30 3/4 and  $30 3/4, respectively, (ii) IES  Common Stock on the  NYSE
were  $27 1/2, $27 and $27 1/8, respectively,  and (iii) IPC Common Stock on the
NYSE were $29 7/8, $29 5/8, and $29 5/8, respectively. On May 22, 1996, the last
full trading day before the public announcement of the execution and delivery of
the amendment to the  Merger Agreement, the high,  low and closing sales  prices
per  share  of (i)  WPLH Common  Stock on  the NYSE  were $30  3/4, $30  5/8 and
$30 3/4, respectively, (ii) IES Common Stock  on the NYSE were $28 5/8, $28  1/4
and  $28 1/2, respectively, and (iii) IPC Common Stock on the NYSE were $31 1/8,
$31 and $31, respectively.
 
    For calendar year 1995, dividends paid per share of common stock were  $1.94
for  WPLH, $2.10 for IES  and $2.08 for IPC.  WPLH's current annualized dividend
rate is $1.97 per  share. It is anticipated  that Interstate Energy will  retain
WPLH's  then current  common share  dividend payment  level as  of the Effective
Time. Assuming the WPLH annual dividend level remains $1.97 as of the  Effective
Time,  and giving effect to the Ratios,  former holders of IES Common Stock will
receive an annual dividend  equivalent to approximately $1.99  per share of  IES
Common Stock held immediately preceding the Effective Time and former holders of
IPC  Common Stock  will receive an  annual dividend  equivalent to approximately
$2.187 per share of  IPC Common Stock held  immediately preceding the  Effective
Time.
 
    On July 9, 1996, the most recent date for which it was practicable to obtain
market    price   data   prior   to   the   printing   of   this   Joint   Proxy
Statement/Prospectus, the high, low and closing  sales prices per share of  WPLH
Common  Stock on the NYSE were $32, $31 5/8 and $31 3/4, respectively, the high,
low and closing  sales prices per  share of IES  Common Stock on  the NYSE  were
$29  1/2, $29 1/4 and $29 3/8, respectively, and the high, low and closing sales
prices per share  of IPC  Common Stock on  the NYSE  were $31 1/8,  $30 5/8  and
$30  5/8, respectively. Accordingly, if the Mergers had been consummated on that
date, each share of IES Common Stock would have been converted into the right to
receive 1.01 shares of WPLH Common Stock  having a market value of $32.07  based
upon  the closing  price per share  of WPLH Common  Stock on such  date and each
share of IPC Common Stock  would have converted into  the right to receive  1.11
shares of WPLH Common Stock having a market value of $35.24 based on the closing
price per share of WPLH Common Stock on such date.
 
    The  market prices  of WPLH  Common Stock, IES  Common Stock  and IPC Common
Stock are  subject to  fluctuation. WPLH  shareowners, IES  shareowners and  IPC
shareowners are urged to obtain current market quotations for WPLH Common Stock,
IES Common Stock and IPC Common Stock.
 
                                       25
<PAGE>
                          MEETINGS, VOTING AND PROXIES
 
    This  Joint Proxy Statement/Prospectus is being furnished to (i) the holders
of WPLH Common Stock in connection with the solicitation of proxies by the  WPLH
Board  from the holders of  WPLH Common Stock for use  at the WPLH Meeting, (ii)
the holders of IES Common Stock  in connection with the solicitation of  proxies
by the IES Board from the holders of IES Common Stock for use at the IES Meeting
and (iii) the holders of IPC Common Stock in connection with the solicitation of
proxies by the IPC Board from the holders of IPC Common Stock for use at the IPC
Meeting.
 
THE WPLH MEETING
 
    PURPOSE OF WPLH MEETING.  The purpose of the WPLH Meeting is to consider and
vote  upon: (i) a proposal to approve  the Merger Agreement and the transactions
contemplated thereby (including, among other  things, the issuance of shares  of
Interstate  Energy Common Stock pursuant to  the terms of the Merger Agreement);
(ii) a  proposal to  approve the  Name  Change Amendment  and the  Common  Stock
Amendment;  (iii)  a proposal  to elect  a  total of  three directors  for terms
expiring at  the 1999  annual meeting  of  shareowners of  WPLH or  until  their
successors  have been  duly elected  and qualified;  (iv) a  proposal to appoint
Arthur Andersen LLP as independent auditors of WPLH for the year ending December
31, 1996; and (v) such  other matters, if any, as  may properly come before  the
WPLH  Meeting. The WPLH  Board is not aware,  as of the date  of mailing of this
Joint Proxy Statement/Prospectus, of any  other matters which may properly  come
before the WPLH Meeting. If any such other matters properly come before the WPLH
Meeting,  or any adjournment or postponement thereof, it is the intention of the
persons named in the WPLH  proxy to vote such  proxies in accordance with  their
best judgment on such matters.
 
    The WPLH Board, by unanimous vote of the directors present, has approved the
Merger  Agreement  and  each  of the  WPLH  Charter  Amendments,  authorized the
execution and  delivery  of  the  Merger Agreement,  and  recommends  that  WPLH
shareowners vote FOR approval of the Merger Agreement (including the issuance of
shares  of Interstate Energy  Common Stock pursuant  to the terms  of the Merger
Agreement), FOR  approval  of each  of  the  WPLH Charter  Amendments,  FOR  the
election  of  the nominated  WPLH directors  and FOR  the appointment  of Arthur
Andersen LLP as independent auditors.
 
    Pursuant to the Merger Agreement, consummation of the Mergers is conditioned
upon approval by the  shareowners of WPLH  of proposals (i)  and (ii) set  forth
above,  but is not conditioned  upon approval of the  shareowners of WPLH of any
other of the above proposals. If  approved, each of the WPLH Charter  Amendments
will become effective only if the Mergers are consummated.
 
    DATE, PLACE AND TIME; RECORD DATE.  The WPLH Meeting is scheduled to be held
on Thursday, September 5, 1996, immediately following the annual meeting of WP&L
which  will be held at  10:00 a.m., Central Time, at  the Exhibition Hall at the
Dane County Expo Center, 1881 Expo  Mall, Madison, Wisconsin. Holders of  record
of  WPLH Common Stock at the close of business on July 10, 1996, the WPLH Record
Date, will be entitled to notice of and  to vote at the WPLH Meeting. As of  the
close  of business  on the  WPLH Record Date,  30,795,260 shares  of WPLH Common
Stock were issued and outstanding and entitled to vote.
 
    VOTING RIGHTS.  Each outstanding share  of WPLH Common Stock is entitled  to
one vote upon each matter presented at the WPLH Meeting. A majority of the votes
entitled  to be cast  by holders of  shares of WPLH  Common Stock represented in
person or by proxy, shall constitute a  quorum for each matter presented at  the
WPLH  Meeting. Abstentions and  broker non-votes (I.E.,  proxies from brokers or
nominees indicating that such  persons have not  received instructions from  the
beneficial  owners or other persons entitled to  vote shares as to a matter with
respect to which brokers  or nominees do not  have discretionary power to  vote)
will be considered present for the purpose of establishing a quorum.
 
    If  a quorum  is present, the  affirmative vote  of a majority  of the votes
entitled to be  cast by the  holders of  the outstanding shares  of WPLH  Common
Stock  entitled to vote thereon is required for approval of the Merger Agreement
(including   the   issuance    of   shares   of    Interstate   Energy    Common
 
                                       26
<PAGE>
Stock pursuant to the terms of the Merger Agreement). Under applicable Wisconsin
law,  in determining  whether the  Merger Agreement  (including the  issuance of
shares of Interstate  Energy Common Stock  pursuant to the  terms of the  Merger
Agreement)  has received the requisite  number of affirmative votes, abstentions
and broker non-votes will have the same effect as votes cast against approval of
the Merger Agreement. Failure to return a WPLH proxy or to vote in person at the
WPLH Meeting will have the effect of  a vote against the Merger Agreement. If  a
quorum  is present, the affirmative vote of  a majority of the votes entitled to
be cast by the  holders of the  shares of WPLH Common  Stock represented at  the
WPLH  Meeting and entitled to  vote thereon is required  for approval of each of
the WPLH Charter Amendments  and for the appointment  of Arthur Andersen LLP  as
WPLH's independent auditors for the year ending December 31, 1996. In tabulating
the  votes for each  of the WPLH  Charter Amendments and  for the appointment of
Arthur Andersen LLP, an abstention has the same effect as a vote against,  while
broker  non-votes are treated as shares not entitled to vote. The directors will
be elected by  a plurality of  the votes cast  at the WPLH  Meeting (assuming  a
quorum  is present).  Consequently, any  shares not  voted at  the WPLH Meeting,
whether due to abstentions or otherwise, will have no impact on the election  of
directors.  The directors  and executive officers  of WPLH,  together with their
affiliates as a group, are deemed to own beneficially less than 1% of the issued
and outstanding shares of WPLH Common Stock.
 
    PROXIES.  Holders of the WPLH Common  Stock may vote either in person or  by
properly executed proxy. By completing and returning the form of proxy, the WPLH
shareowner   authorizes  the  persons  named  therein   to  vote  all  the  WPLH
shareowner's shares on his or her behalf. Issued and outstanding shares of  WPLH
Common  Stock which  are represented by  properly executed  proxies will, unless
such proxies have  been revoked, be  voted in accordance  with the  instructions
indicated  in  such proxies.  If  no instructions  are  indicated on  a properly
executed proxy, such shares will be  voted FOR approval of the Merger  Agreement
(including  the issuance of shares of Interstate Energy Common Stock pursuant to
the terms of the  Merger Agreement), FOR  approval of each  of the WPLH  Charter
Amendments,  FOR the election of the nominated directors and FOR the appointment
of Arthur  Andersen LLP  as  WPLH's independent  auditors  for the  year  ending
December  31, 1996. A WPLH proxy may be  revoked by voting in person at the WPLH
Meeting, by written notice  to WPLH's Corporate Secretary,  or by delivery of  a
duly  executed proxy bearing a later date, in  each case prior to the closing of
the polls for voting at  the WPLH Meeting. Attendance  at the WPLH Meeting  will
not in itself constitute revocation of a proxy.
 
    If  an individual is a participant in the WP&L Employees' Retirement Savings
Plan (the "WP&L Savings Plan"), the participant will receive a voting  directive
from  the WP&L Savings Plan trustee for shares of WPLH Common Stock allocated to
the participant's account under the WP&L Savings Plan. The trustee for the  WP&L
Savings  Plan will vote such  shares as instructed by  the participant in his or
her voting directive. If a participant does not return a voting directive,  such
participant's  shares will be voted by the  trustee for the WP&L Savings Plan in
its absolute discretion and in accordance with ERISA (as hereinafter defined).
 
    If a WPLH shareowner is a participant in the WPLH Dividend Reinvestment  and
Stock  Purchase Plan (the "WPLH DRIP"), the WPLH proxy will represent the shares
held on behalf of the  participant under the WPLH DRIP  and such shares will  be
voted in accordance with the instructions on the WPLH proxy. If a participant in
the WPLH DRIP does not return a WPLH proxy, the participant's shares will not be
voted.
 
    WPLH will bear the cost of the solicitation of proxies for the WPLH Meeting,
except  that WPLH,  IES and IPC  have agreed  to share the  expenses incurred in
connection with printing and filing  this Joint Proxy Statement/Prospectus  (43%
by  WPLH, 43% by IES and 14% by IPC). See "The Merger Agreement -- Expenses." In
addition to soliciting proxies by mail, officers and employees of WPLH,  without
receiving  additional compensation  therefor, may solicit  proxies by telephone,
telecopy, telegram or in person. WPLH, IES  and IPC have retained Morrow &  Co.,
Inc. to assist in the solicitation of
 
                                       27
<PAGE>
proxies  from their respective  shareowners, including brokers'  accounts, at an
aggregate fee  for  such  services  of $15,000  plus  an  additional  $2.00  per
shareowner contact and reasonable out-of-pocket expenses.
 
    The  WPLH Meeting  may be  adjourned to  another date  and/or place  for any
proper purpose (including,  without limitation,  for the  purpose of  soliciting
additional proxies).
 
THE IES MEETING
 
    PURPOSE  OF IES MEETING.  The purpose of  the IES Meeting is to consider and
vote upon: (i) a proposal to  approve the Merger Agreement and the  transactions
contemplated  thereby; (ii)  a proposal  to elect a  board of  nine directors to
serve until the next annual meeting  or until their successors are duly  elected
and qualified; and (iii) such other matters, if any, as may properly come before
the  IES Meeting. The IES Board is not aware,  as of the date of mailing of this
Joint Proxy Statement/ Prospectus, of any other matters which may properly  come
before  the IES Meeting. If any such  other matters properly come before the IES
Meeting, or any adjournment or postponement thereof, it is the intention of  the
persons  named in the  IES proxy to  vote such proxies  in accordance with their
best judgment on such matters.
 
    The IES Board, by  unanimous vote of the  directors present at the  meeting,
has  approved the Merger Agreement, authorized the execution and delivery of the
Merger Agreement, and recommends that IES shareholders vote FOR approval of  the
Merger Agreement and FOR the election of the nominated IES directors.
 
    Pursuant to the Merger Agreement, consummation of the Mergers is conditioned
upon approval by the shareholders of IES of proposal (i) set forth above, but is
not conditioned upon approval by the shareholders of IES of any other proposal.
 
    DATE,  PLACE AND TIME; RECORD DATE.  The IES Meeting is scheduled to be held
on Thurssday, September  5, 1996, at  10:00 a.m., Central  Time, at the  Collins
Plaza  Hotel, 1200 Collins Road  N.E., Cedar Rapids, Iowa.  Holders of record of
IES Common Stock at the close of business on July 10, 1996, the IES Record Date,
will be entitled to notice of and to vote at the IES Meeting. As of the close of
business on the  IES Record  Date, 29,923,233 shares  of IES  Common Stock  were
issued and outstanding and entitled to vote.
 
    VOTING  RIGHTS.  Each outstanding  share of IES Common  Stock is entitled to
one vote upon each matter presented at the IES Meeting. A majority of the  votes
entitled  to be cast  by holders of  shares of IES  Common Stock, represented in
person or by proxy, shall constitute a  quorum for each matter presented at  the
IES  Meeting. Abstentions  and broker non-votes  (I.E., proxies  from brokers or
nominees indicating that such  persons have not  received instructions from  the
beneficial  owners or other persons entitled to  vote shares as to a matter with
respect to which brokers  or nominees do not  have discretionary power to  vote)
will be considered present for the purpose of establishing a quorum.
 
    If  a quorum is present, (i) the affirmative vote of a majority of the votes
entitled to be cast by the holders of the outstanding shares of IES Common Stock
entitled to vote thereon is required  for approval of the Merger Agreement,  and
(ii)  the affirmative vote of a majority of the votes entitled to be cast by the
holders of the  outstanding shares of  IES Common Stock  represented at the  IES
Meeting  and entitled to vote thereon is required for the election of directors.
Under applicable Iowa law, in determining  whether the Merger Agreement and  the
nominees  for directors have received the requisite number of affirmative votes,
abstentions and broker non-votes will have the same effect as votes cast against
approval of  the Merger  Agreement  and against  approval  of the  nominees  for
director. Failure to return an IES proxy or to vote in person at the IES Meeting
will also have the effect of a vote against the Merger Agreement and against the
nominees  for director.  The directors and  executive officers  of IES, together
with their affiliates as a group, are deemed to own beneficially less than 1% of
the issued and outstanding shares of IES Common Stock.
 
                                       28
<PAGE>
    PROXIES.   Holders of  IES Common  Stock may  vote either  in person  or  by
properly  executed proxy. By completing and returning the form of proxy, the IES
shareholder  authorizes  the  persons  named   therein  to  vote  all  the   IES
shareholder's  shares on his or her behalf. Issued and outstanding shares of IES
Common Stock which  are represented  by properly executed  proxies will,  unless
such  proxies have  been revoked, be  voted in accordance  with the instructions
indicated on  such proxies.  If  no instructions  are  indicated on  a  properly
executed  proxy, such shares will be voted  FOR approval of the Merger Agreement
and FOR the election of the nominated directors. An IES proxy may be revoked  by
voting in person at the IES Meeting, by written notice to IES's Secretary, or by
delivery  of a duly executed  proxy bearing a later date,  in each case prior to
the closing of the polls  for voting at the IES  Meeting. Attendance at the  IES
Meeting will not in itself constitute revocation of proxy.
 
    The  proxy/directions cards  enclosed have  imprinted thereon  the number of
shares of IES Common Stock held of record as well as shares held for the account
of shareholder participants in the IES Dividend Reinvestment and Stock  Purchase
Plan.  Proxy/directions cards for shareholders who  are employees of IES and who
are  participants  in  the  IES  Employee  Stock  Purchase  Plan,  the  Dividend
Reinvestment  and Stock Purchase Plan or the IES Bonus Stock Ownership Plan will
also have  imprinted  thereon the  number  of shares  held  for the  account  of
participants  in that plan. Employees who are not shareholders of record but who
are participants in any of the plans  will receive a proxy/ directions card  for
shares being held for them pursuant to such plan. The number of shares imprinted
on the proxy/directions cards are the number of shares to be voted in accordance
with the instructions of the shareholder or plan participant.
 
    All  shares of IES Common Stock held  for the account of participants in the
IES Dividend Reinvestment  and Stock  Purchase Plan, IES  Bonus Stock  Ownership
Plan  and the IES Employee Stock Purchase Plan, respectively, are held of record
by the Shareholder  Services Department of  IES. All shares  held in such  plans
will  be voted by said  Department in the manner  indicated by the participant's
proxy/directions card.  Participants  in  the Iowa  Southern  Utilities  Company
Employee  Stock Ownership Plan  will receive a  proxy/directions card for shares
being held for them pursuant to such plan. The number of shares imprinted on the
proxy/directions card are the  number of shares to  be voted in accordance  with
the instructions of the participant. All shares of IES Common Stock held for the
account  of such participants are  held of record by  Stephen W. Southwick (Vice
President, General Counsel & Secretary of  IES), as Trustee. All shares held  in
such  plan  will  be  voted  by  the Trustee  in  the  manner  indicated  by the
participant's proxy/direction card.
 
    Employees who  are participants  in the  IES Common  Stock Fund  of the  IES
Employee Savings Plan will receive a proxy/directions card from American Express
Trust  Company, as Trustee, the  holder of record for  shares held in such plan.
The proxy/directions cards have imprinted thereon the number of shares held  for
the  account  of  each  participant.  The  number  of  shares  imprinted  on the
proxy/directions card  will be  voted  by the  Trustee  in accordance  with  the
instructions  of the participant.  Shares not voted by  the participants will be
voted by the Trustee as the Employee Savings Plan Committee of IES directs.
 
    IES will bear the cost of the  solicitation of proxies for the IES  Meeting,
except  that IES,  WPLH and IPC  have agreed  to share the  expenses incurred in
connection with printing and filing  this Joint Proxy Statement/Prospectus  (43%
by  IES, 43% by  WPLH and 14% IPC).  See "The Merger  Agreement -- Expenses." In
addition to soliciting proxies by mail,  officers and employees of IES,  without
receiving  additional compensation  therefor, may solicit  proxies by telephone,
telecopy, telegram or in person. IES, WPLH  and IPC have retained Morrow &  Co.,
Inc.   to  assist  in   the  solicitation  of   proxies  from  their  respective
shareholders, including brokers' accounts, at an aggregate fee for such services
of $15,000  plus an  additional  $2.00 per  shareholder contact  and  reasonable
out-of-pocket expenses.
 
    The IES Meeting may be adjourned to another date and/or place for any proper
purpose (including, without limitation, for the purpose of soliciting additional
proxies).
 
                                       29
<PAGE>
THE IPC MEETING
 
    PURPOSE  OF THE IPC MEETING.  The purpose  of the IPC Meeting is to consider
and vote  upon:  (i)  a  proposal  to  approve  the  Merger  Agreement  and  the
transactions  contemplated thereby; (ii)  a proposal to  approve the IPC Charter
Amendment; (iii) a proposal to elect two Class II directors to hold office for a
term of three years expiring at the 1999 annual meeting of stockholders of  IPC,
or until their respective successors shall have been duly elected and qualified;
and  (iv)  such other  matters,  if any,  as may  properly  come before  the IPC
Meeting. The IPC Board  is not aware, as  of the date of  mailing of this  Joint
Proxy  Statement/Prospectus, of any other matters which may properly come before
the IPC Meeting. If any such other matters properly come before the IPC Meeting,
or any adjournment or postponement thereof,  it is the intention of the  persons
named  in  the IPC  proxy to  vote such  proxies in  accordance with  their best
judgment on such matters.
 
    The IPC  Board,  by  unanimous  vote, has  approved  the  Merger  Agreement,
authorized  the  execution  and  delivery of  the  Merger  Agreement,  adopted a
resolution  setting  forth   the  IPC  Charter   Amendment  and  declaring   its
advisability,  and recommends  that IPC  stockholders vote  FOR approval  of the
Merger Agreement, FOR approval of the IPC Charter Amendment and FOR the election
of the nominated IPC directors.
 
    Pursuant to the Merger Agreement, consummation of the Mergers is conditioned
upon approval by the  stockholders of IPC  of proposals (i)  and (ii) set  forth
above,  but is not conditioned  upon approval by the  stockholders of IPC of any
other proposal.
 
    DATE, PLACE AND TIME; RECORD DATE.  The IPC Meeting is scheduled to be  held
on  Thursday, September 5, 1996, at 10:00 a.m., Central Time, at the Holiday Inn
Dubuque Five Flags,  450 Main Street,  Dubuque, Iowa. Holders  of record of  IPC
Common  Stock at the  close of business on  July 10, 1996,  the IPC Record Date,
will be entitled to notice of and to vote at the IPC Meeting. As of the close of
business on  the IPC  Record Date,  9,595,028 shares  of IPC  Common Stock  were
issued and outstanding and entitled to vote.
 
    VOTING  RIGHTS.  Each outstanding  share of IPC Common  Stock is entitled to
one vote upon each matter presented at the IPC Meeting. A majority of the  votes
entitled  to be cast  by holders of  shares of IPC  Common Stock, represented in
person or by proxy, shall constitute a quorum. Abstentions and broker  non-votes
(I.E.,  proxies from brokers  or nominees indicating that  such persons have not
received instructions from the  beneficial owners or  other persons entitled  to
vote shares as to a matter with respect to which brokers or nominees do not have
discretionary  power  to vote)  will be  considered present  for the  purpose of
establishing a quorum.
 
    The affirmative  vote of  a majority  of the  outstanding IPC  Common  Stock
entitled  to vote is required for approval  of the Merger Agreement and approval
of the IPC Charter Amendment, and a  plurality of votes cast at the IPC  Meeting
is required for the election of directors.
 
    As to the votes on the Merger Agreement and the IPC Charter Amendment before
stockholders  at the IPC Meeting, abstentions and broker non-votes will have the
same effect as votes cast against approval  of the Merger Agreement and the  IPC
Charter  Amendment. As to  the election of directors  before stockholders at the
IPC Meeting, abstentions and broker non-votes will have no effect. The directors
and executive officers of  IPC, together with their  affiliates as a group,  are
deemed  to own beneficially less than 1% of the issued and outstanding shares of
IPC Common Stock.
 
    PROXIES.  Holders of the  IPC Common Stock may vote  either in person or  by
properly  executed proxy. By completing and returning the form of proxy, the IPC
stockholder  authorizes  the  persons  named   therein  to  vote  all  the   IPC
stockholder's  shares on his  or her behalf. All  completed IPC proxies returned
will be voted in accordance with the instructions indicated on such proxies.  If
no  instructions are given on a properly executed proxy, the IPC proxies will be
voted FOR approval  of the  Merger Agreement, FOR  approval of  the IPC  Charter
Amendment  and FOR election of the two Class II directors recommended by the IPC
Board.  An   IPC  proxy   may  be   revoked   by  voting   in  person   at   the
 
                                       30
<PAGE>
IPC Meeting, by written notice to IPC's Corporate Secretary, or by delivery of a
duly  executed proxy bearing a later date, in  each case prior to the closing of
the polls for voting at the IPC Meeting. Attendance at the IPC Meeting will  not
in itself constitute revocation of a proxy.
 
    For  stockholders  participating in  IPC's  Dividend Reinvestment  and Stock
Purchase Plan (the "IPC DRSPP"), the enclosed proxy will represent the number of
shares registered in the participating  stockholder's name and/or the number  of
shares allocated to the participating stockholder's account (the "DRSPP Shares")
under the IPC DRSPP. The enclosed proxy will serve as the instructions as to how
to  vote the DRSPP Shares.  If a participating stockholder  does not furnish any
proxy to vote  the DRSPP  Shares, that stockholder's  DRSPP Shares  will not  be
voted.
 
    IPC  employees that  participate in  the IPC  Common Stock  Fund of  the IPC
401(k) Plan will receive a proxy from  Dubuque Bank & Trust Company (the  401(k)
Plan  Trustee and the holder of record for  shares held in the IPC 401(k) Plan).
The proxy will have imprinted thereon the number of shares held for the  account
of  each participant in the  IPC 401(k) Plan. The  number of shares imprinted on
the proxy will be voted  by the IPC 401(k) Plan  Trustee in accordance with  the
instructions of the IPC 401(k) Plan participant.
 
    IPC  will bear the cost of the  solicitation of proxies for the IPC Meeting,
except that IPC,  WPLH and IES  have agreed  to share the  expenses incurred  in
connection  with printing and filing  this Joint Proxy Statement/Prospectus (14%
by IPC, 43% by WPLH and 43% by IES). See "Merger Agreement -- Expenses." Proxies
may be solicited by certain officers and employees of IPC or its subsidiaries by
mail, by telephone, personally or by other communications, without  compensation
apart  from their normal salaries. IPC, WPLH and IES have retained Morrow & Co.,
Inc.  to  assist  in   the  solicitation  of   proxies  from  their   respective
stockholders, including brokers' accounts, at an aggregate fee for such services
of  $15,000  plus an  additional $2.00  per  stockholder contact  and reasonable
out-of-pocket expenses.
 
    The IPC Meeting may be adjourned to another date and/or place for any proper
purpose (including, without limitation, for the purpose of soliciting additional
proxies).
 
                                  THE MERGERS
 
BACKGROUND OF THE MERGERS
 
    Each of  WPLH,  IES  and  IPC  believes  that  fundamental  changes  in  the
regulatory  structure of the  electric utility industry  are inevitable and that
such changes will likely occur in the near future. Recently enacted federal laws
and actions by  federal and  state regulatory commissions  are facilitating  the
changes to bring more competition to various segments of the industry.
 
    The Energy Policy Act of 1992 (the "1992 Act") granted FERC the authority to
order  electric utilities to provide transmission service to other utilities and
to other buyers and sellers of electricity in the wholesale market. The 1992 Act
also created  a  new  class  of power  producers,  exempt  wholesale  generators
("EWGs"),  which are  exempt from regulation  under the 1935  Act. The exemption
from regulation under the 1935 Act of EWGs has increased the number of  entrants
into  the wholesale electric  generation market, thus  increasing competition in
the wholesale segment of the electric utility industry.
 
    Commencing in December 1993, pursuant to  its authority under the 1992  Act,
FERC  issued a number of orders in specific cases directing utilities to provide
transmission services. Under  FERC's evolving  transmission policies,  utilities
are  being required to offer  transmission services to third  parties on a basis
comparable to services  that the utilities  provide themselves. FERC  is in  the
process  of  rulemaking pursuant  to  which it  is  seeking to  implement,  on a
comprehensive basis, the  comparable transmission  service policies  it has  set
forth  in  these specific  cases. FERC's  actions to  date and  its transmission
rulemaking proceeding have increased the availability of transmission  services,
thus creating greater competition in the wholesale power market.
 
                                       31
<PAGE>
    In addition, state regulatory bodies in over thirty states, including, among
others,  Wisconsin, Illinois, Iowa and  Minnesota, have initiated proceedings to
review the basic structure of the industry. These bodies are considering, or may
soon consider, proposals to  require some measure of  competition in the  retail
portion  of the industry.  The Wisconsin Commission  requested comment regarding
how the industry  might be restructured  in order to  create a more  competitive
environment.  Following receipt of responses, the Wisconsin Commission created a
task force to  analyze how the  industry might be  restructured in Wisconsin  to
allow  consumers to receive  the benefits of  increased competition. On December
19, 1995,  following receipt  of the  report of  the task  force, the  Wisconsin
Commission  agreed to take steps to  further increase competition in Wisconsin's
electric utility industry within  five years. While the  outcome of the  actions
described above is uncertain, it remains the view of the management of WPLH, IES
and  IPC  that there  will  ultimately be  increased  competition in  the retail
segment of the business.
 
    The changes  to  the electric  industry  that  have occurred  and  that  are
occurring  are bringing increased competition to various sectors of the business
and are putting pressure on  utilities to lower their  costs. Each of WPLH,  IES
and  IPC recognized  that a combination  with one or  more appropriate utilities
would enable the combined entity to generate and deliver energy more cheaply and
efficiently  and  thereby  remain  a  competitive  supplier  of  energy  in   an
increasingly competitive industry.
 
    Over  the  last  several  years, the  management  of  WPLH  has periodically
analyzed various potential strategic  options that might  be available to  WPLH,
including possible business combinations or alliances with other utilities. WPLH
management  considered the possibility of  pursuing business combinations with a
number of the  utilities with  service areas proximate  to the  service area  of
WP&L,  as well as  other utilities with  Midwestern operations, and periodically
briefed the WPLH Board on such matters. Based on a cost-benefit analysis of  the
potential  strategic options considered, WPLH  management determined the options
studied were not in  the best interests  of WPLH and  its shareowners. In  early
February  1995,  during  the  continuation  of one  of  its  reviews  of various
strategic alternatives, WPLH management concluded  that, among others, both  IES
and  IPC  were prospective  merger partners  that would  provide a  good overall
strategic fit.  WPLH's  management based  its  conclusions on  various  factors,
including low-cost structure, competitive energy rates, potential merger-related
cost savings, economies of scale, marketing potential and similar shareowner and
common  stock trading characteristics. These reasons, combined with the physical
proximity of the respective  companies' service areas  and the compatibility  of
and  similarity between the  companies' operations and  management, made IES and
IPC natural combination partners for WPLH.
 
    IES has believed  for many  years that consolidation  of electric  utilities
within  the State of Iowa would be  both desirable and inevitable. In July 1991,
Iowa Southern Inc. and IE Industries Inc.  merged to form IES. The utilities  in
that  merger, Iowa Southern Utilities Company  and Iowa Electric Light and Power
Company, merged  in December  1993 to  form Utilities.  Since the  1991  merger,
management   of  IES  has   continued  to  assess   other  possible  combination
transactions both in the State of Iowa and generally in the Midwest. In December
1992, IES acquired certain electric utility  assets and properties in Iowa  from
Union  Electric Company.  Preliminary discussions with  respect to consolidation
transactions were held  from time  to time  between representatives  of IES  and
other utilities in the Midwest, including IPC. IES management recognized that in
the increasingly competitive market for electric power, important criteria would
include  low cost production, efficiencies of scale, transmission capability, as
well as  cultural fit  between  possible partners  and resolution  of  corporate
governance  and  other  issues.  In  December  1994,  IES  determined  to pursue
aggressively process reengineering  to reduce costs  and create efficiencies  in
its electric and gas utility businesses. Management of IES continued to consider
potential  combination  transactions both  as an  additional means  of realizing
higher efficiency levels and as a means to increase shareholder value.
 
    For the past several years, IPC has been monitoring the changes occurring in
the electric and gas  utility industry and conducting  strategic planning in  an
effort  to remain competitive in the changing environment. During that time, IPC
has been approached  by representatives  of other utilities  (including IES)  in
connection  with potential business  combinations, but has  not held substantive
discussions
 
                                       32
<PAGE>
on any specific proposed  combination. During the eighteen  months prior to  the
execution  of  the  Merger Agreement,  the  management of  IPC  analyzed various
potential strategic options that might  be available to IPC, including  possible
business  combinations or strategic  alliances with other  utilities, as well as
options that could be pursued by IPC on a stand-alone basis. In examining  these
potential  strategic initiatives, IPC management  determined that, at that time,
and based upon the circumstances then  existing, IPC and its stockholders  would
be  best  served  by  a  strengthening  of  IPC  on  a  stand-alone  basis. This
determination was made by IPC management based upon its subjective assessment of
the  potential  benefits  and  potential  risks  of  each  of  the  alternatives
considered. In April 1995, IPC management proposed to the IPC Board, and the IPC
Board  approved,  a  series  of strategic  steps  to  be pursued  by  IPC  on an
independent basis.  These  strategic  steps included  initiatives  to:  increase
energy  sales consistent with efficient energy usage; enhance efforts to improve
productivity and efficiency; leverage existing skills and resources to  increase
revenues  and  earnings through  new service  offerings;  focus the  core energy
service business  to be  customer  driven; prepare  the generation  segment  for
potential  unregulated market;  intensify efforts  to earn  the allowed  rate of
return in all  jurisdictions in  which IPC  does business;  and investigate  the
potential for diversification into non-core businesses.
 
    Over  the last several years, as  the foregoing issues were being considered
by the  management of  each of  WPLH, IES  and IPC,  Messrs. Liu  and Davis  and
Messrs.  Liu and  Stoppelmoor held  general discussions  concerning the evolving
nature of the electric utility industry. In  May 1995, Mr. Davis called Mr.  Liu
to schedule a meeting to discuss in a more focussed manner the views of WPLH and
IES  regarding  the future  of the  utility  industry. That  call resulted  in a
meeting on May 18, 1995 at which  the concept of a business combination  between
WPLH  and IES and a subsequent combination between the combined WPLH/IES and IPC
were discussed in a very preliminary fashion. At that meeting, Messrs. Davis and
Liu also identified the issues  of management succession, board composition  and
various  utility  integration  strategies  as  significant  points  in  any such
business combination  to be  agreed upon,  and agreed  that discussions  between
representatives of WPLH and IES should be initiated.
 
    On  May 23  and June 12,  1995, Eliot  G. Protsch, Senior  Vice President of
WP&L, and Robert J. Latham, then Senior  Vice President, Finance of IES, met  to
compare  corporate  strategies and  discuss the  potential synergies  that could
result from  a business  combination between  WPLH and  IES. At  such  meetings,
Messrs.  Protsch and Latham also discussed  various strategies on how to further
the discussions  that  had  occurred from  time  to  time between  IES  and  IPC
regarding  a possible  business combination between  IES and IPC.  At the latter
meeting, WPLH  and IES  entered into  a confidentiality  agreement, pursuant  to
which  the parties agreed to exchange non-public information with a view towards
exploring a possible business combination.
 
    On June 22, 1995, at a regularly  scheduled meeting of the WPLH Board  which
took place in Washington D.C., a number of outside experts gave presentations to
the  WPLH  Board regarding,  among other  things, the  evolution of  the utility
industry towards a more competitive environment and the consolidation  occurring
in  the industry. At the June 22 meeting, WPLH management also informed the WPLH
Board of the meetings that  had taken place between  WPLH and IES and  discussed
the  overall concept  of a  business combination  between WPLH  and IES  and the
possibility that such combination  would potentially be  followed by a  business
combination  with IPC. At this meeting,  the WPLH Board authorized management to
retain financial and legal advisors to assist with the potential transaction.
 
    After the June 22, 1995 meeting, WPLH engaged Merrill Lynch as its exclusive
financial advisor to  assist WPLH  in analyzing,  structuring, negotiating,  and
effecting  the  possible  transaction.  As described  in  greater  detail below,
Merrill Lynch,  in the  course of  its engagement,  primarily performed  various
financial analyses and financial due diligence regarding each of the parties. In
addition,   Merrill  Lynch  provided  advice   regarding,  and  participated  in
discussions concerning, exchange  ratios. Merrill Lynch  also participated  from
time    to   time    in   discussions    regarding   the    structure   of   the
 
                                       33
<PAGE>
transaction, although structural issues were predominantly influenced by tax and
regulatory considerations.  In addition,  following the  June 22  meeting,  WPLH
engaged  Foley & Lardner, its outside law firm, to advise it with respect to the
potential business combination.
 
    On June 27,  1995, Mr.  Liu met  in Dubuque,  Iowa with  Mr. Stoppelmoor  to
determine  if IPC would be interested in  entering into a two-way or a three-way
business combination. At that meeting, Mr. Liu and Mr. Stoppelmoor discussed the
perceived potential benefits that could accrue to IPC stockholders in a  two-way
or  three-way  business combination.  Mr.  Stoppelmoor indicated  that  he would
consider the  matters  discussed at  this  meeting and,  if  appropriate,  would
respond to Mr. Liu.
 
    On June 29 and 30, 1995, officers of WPLH and IES, including Mr. Protsch and
William  D. Harvey, Senior Vice  President of WP&L, and  Mr. Latham and Blake O.
Fisher, then Executive Vice President and Chief Financial Officer of IES, met to
further review strategic compatibility  of the two  companies and the  potential
synergies  that could result from  a potential business combination transaction,
and to discuss possible preliminary timetables for such a transaction.
 
    On June  30, 1995,  IES formally  engaged Morgan  Stanley as  its  financial
advisor  in connection  with this possible  transaction. During the  term of its
engagement, Morgan Stanley provided IES with financial advice and assistance  in
connection  with the  Mergers, including advice  and assistance  with respect to
defining objectives, performing valuation analysis and structuring, planning and
negotiating the transaction. In particular,  and as described in greater  detail
below,  Morgan Stanley,  in the  course of  its engagement,  primarily performed
various financial analyses  and financial  due diligence regarding  each of  the
parties. In addition, Morgan Stanley provided advice regarding, and participated
in  discussions concerning,  exchange ratios.  Morgan Stanley  also participated
from time to  time in discussions  regarding the structure  of the  transaction,
although  structural issues were predominantly  influenced by tax and regulatory
considerations.
 
    On July 3, 1995, Messrs. Davis and  Liu met in Madison, Wisconsin to  review
the  status of the potential transaction  and further discuss issues relating to
management succession, the  composition of the  combined corporation's board  of
directors and various utility integration strategies.
 
    On  July 8, 1995, the IES Board held  a special meeting at which Mr. Liu and
representatives of Morgan Stanley and Winthrop, Stimson, Putnam & Roberts, IES's
outside law firm, briefed the members of  the IES Board on discussions that  had
been  taking place  with WPLH and  IPC. At  this meeting, the  merger of Midwest
Resources Inc.  and  Iowa-Illinois Gas  and  Electric Company,  which  had  been
announced  on July 27, 1994,  was also discussed. Mr.  Liu presented profiles of
both IES and WPLH and noted a number of areas of compatibility and opportunities
which could  result from  a combination  between  IES and  WPLH. The  IES  Board
considered  that strategic  combination alternatives  for IES  were limited, and
that  the  number  of  possible  partners,  following  the  Midwest   Resources/
Iowa-Illinois  announcement,  would likely  decline further  over time.  The IES
Board identified a number of concerns that would need to be addressed in further
discussions, such  as the  effects of  Wisconsin regulation  and the  structural
necessity  of becoming a registered holding company  under the 1935 Act. At this
time, the  IES Board  determined that  it  would be  advisable to  proceed  with
discussions  to the next  level and to  begin due diligence  with respect to the
business and legal aspects of a possible combination with WPLH.
 
    On July 12, 1995, the WPLH  Board met with WPLH's advisors.  Representatives
of  Merrill Lynch  discussed their views  on changing conditions  in the utility
industry and  provided financial  profiles and  preliminary valuations  of  IES.
Legal  counsel  for WPLH  explained  the directors'  legal  responsibilities and
presented information as to the regulatory approvals that would be required  for
a  combination with IES, the  standards for review to  be applied by the various
regulatory bodies and the implications of adopting a registered holding  company
structure  under the 1935 Act, including the possibility that divestiture of the
combined entity's gas and certain non-utility operations might be required.  The
WPLH Board discussed the potential benefits to shareowners and customers of WPLH
that  could result  from the proposed  combination and  authorized management to
proceed with the process.
 
                                       34
<PAGE>
    In mid-July 1995, Mr. Liu contacted  Mr. Stoppelmoor to discuss further  the
potential  benefits that could accrue to  IPC and its stockholders and customers
in a  two-way or  three-way  business combination.  At  the conclusion  of  this
conversation,  Mr. Stoppelmoor indicated that he would report Mr. Liu's proposal
to the IPC Board at  its next regularly scheduled meeting  on July 27, 1995  and
would respond to Mr. Liu, if appropriate, following that meeting.
 
    On July 17 and July 24, 1995, Mr. Protsch, Mr. Ahearn, Daniel A. Doyle, Vice
President-Finance,  Controller  and Treasurer  of  WP&L, Barbara  J.  Swan, Vice
President and  General Counsel  of  WP&L, Larry  D.  Root, then  Executive  Vice
President  of IES,  Stephen W.  Southwick, Vice  President, General  Counsel and
Secretary of IES, and  Mr. Fisher, together with  other personnel from WPLH  and
IES,  as well as their financial  and legal advisors, held introductory meetings
to discuss, among other things, a timetable for accomplishing the tasks required
to negotiate, prepare and execute a merger agreement between the two  companies.
At  these  meetings,  due  diligence  was  performed  on  both  the  utility and
non-utility  businesses  of  WPLH  and  IES  and  working  groups  composed   of
representatives  of both companies  were formed to  examine more comprehensively
various  issues   including   corporate  structure,   nonregulated   operations,
environmental  compliance and liabilities,  nuclear generation opportunities and
risks,  reengineering  initiatives  under  way  at  the  companies,   regulatory
considerations,   and  synergy  identification   and  quantification  approaches
relating thereto.
 
    On July 27, 1995, at a meeting of the IPC Board, Mr. Stoppelmoor reported to
the IPC Board that he had been contacted by Mr. Liu with respect to scheduling a
meeting to discuss a potential business combination among IPC, IES and WPLH. The
IPC Board authorized Messrs. Stoppelmoor and Chase to meet with  representatives
of  IES  and  WPLH  to  discuss on  a  preliminary  basis  a  potential business
combination among the companies.
 
    The IES Board met on July 31 and  August 1, 1995, at which time the  results
of  the due diligence investigation conducted to date were presented and further
discussions  were  held  as  to  the  desirability  of  pursuing  a  combination
transaction with WPLH. At this meeting, the IES Board discussed alternatives for
possible  combination partners, as  well as a  strategy of remaining independent
while pursuing the reengineering initiative undertaken earlier in the year.  The
IES Board concluded that it should retain an independent consultant to assist in
evaluating  the strategic alternatives  available to IES. At  the same time, the
IES Board directed management to continue its discussions with WPLH and IPC.
 
    The reengineering initiative  was undertaken by  IES to examine  all of  the
major  business processes of Utilities. The  goals of the initiative as approved
by  the  IES  Board  were  to  improve  customer  service  and  commitment   and
significantly  reduce  Utilities' cost  structure. The  majority of  the changes
identified in connection with the initiative  are intended to be implemented  in
1996.  Such changes include,  but are not  limited to, managing  the business in
business unit form rather than functionally, formation of alliances with vendors
of certain types  of material rather  than opening most  purchases to a  bidding
process,  changing  standards  and construction  practices  in  transmission and
distribution  areas,  changing  certain  work  practice  in  power  plants,  and
improving  the method by which service is delivered to customers in all customer
classes.
 
    On August 9, 1995, Mr. Davis, Mr. Liu, Mr. Stoppelmoor and Mr. Chase met  to
evaluate  IPC's interest in  a three-way business  combination between WPLH, IES
and IPC. At this meeting, the representatives from the three companies discussed
their views on the future of the  utility industry and identified the issues  of
management   succession,  board  composition  and  various  utility  integration
strategies as points to be agreed upon.  At such meeting, IPC informed WPLH  and
IES that the potential three-way transaction would need to be discussed with the
IPC  Board before  IPC would engage  in any substantive  discussions. After such
meeting, Messrs.  Davis and  Liu reviewed  the status  of discussions  that  had
occurred  to date regarding  the potential two-way  business combination between
WPLH and IES.
 
    Over the course of the next two weeks, representatives of both WPLH and  IES
continued   their  work   with  respect   to  the   synergy  identification  and
quantification approaches relating thereto, non-
 
                                       35
<PAGE>
regulated  operations,   environmental  compliance   and  liabilities,   nuclear
generation  opportunities and  risks, reengineering initiatives  underway at the
companies, legal structure, regulatory plans and other due diligence activities.
 
    On August 14, 1995, Arthur Andersen Economic Consulting made a  presentation
to  IES management  and a subcommittee  of the IES  Board discussing competitive
forces in the industry,  regulatory reform proposals  and strategic options  for
utilities.  Arthur Andersen Economic Consulting was thereafter engaged to assist
the IES Board and management  in their consideration of strategic  alternatives,
particularly in the area of possible synergies and/or cost savings that could be
obtained  from various alternative  combination transactions and  as compared to
cost savings which management of IES believed could be obtained on a stand-alone
basis through  process  reengineering.  IES selected  Arthur  Andersen  Economic
Consulting  for this assignment based on the firm's experience and reputation in
providing strategic and regulatory consulting for the electric power and natural
gas industries. Arthur Andersen  Economic Consulting is  an affiliate of  Arthur
Andersen  LLP. Arthur Andersen LLP has served as the independent accountants for
IES and WPLH  for many  years, performing the  independent annual  audit of  the
companies  and  providing  business advisory  and  tax consultation  to  the two
companies. Arthur Andersen LLP has  received customary fees for these  services.
Arthur  Andersen Economic Consulting received a fee of approximately $200,000 in
connection with its services provided to IES.
 
    At a  special  meeting  of  the  IPC  Board  on  August  23,  1995,  Messrs.
Stoppelmoor  and  Chase  reported  to  the  IPC  Board  their  discussions  with
representatives  of  IES  and  WPLH  regarding  a  proposed  three-way  business
combination.  The IPC Board  then discussed the  potential strategic benefits of
such a combination to IPC and its stockholders and customers as compared to  the
potential  benefits of the strategic options  that IPC had earlier determined to
pursue on  a  stand-alone  basis.  The IPC  Board  concluded  that  a  three-way
combination  with  IES  and  WPLH  offered potential  benefits  to  IPC  and its
stockholders (in  the  form  of  a larger,  financially  sound  enterprise  with
potentially  greater earnings and dividend prospects) and to IPC's customers (in
the form of a  more competitive enterprise) and  should be further explored.  At
the  August  23 meeting,  the IPC  Board authorized  IPC management  to continue
discussions  with  representatives  of  IES  and  WPLH  regarding  a   potential
transaction and, in furtherance thereof, authorized IPC management to enter into
a  confidentiality agreement with  IES and WPLH pursuant  to which the companies
would exchange certain non-public information  and authorized IPC management  to
retain  counsel, financial advisors and such  other professional advisors as IPC
management deemed prudent in  assisting IPC in  evaluating a potential  business
combination transaction.
 
    Shortly  after the August 23, 1995  meeting, IPC engaged Salomon Brothers as
its financial advisor to assist  IPC in analyzing, structuring, negotiating  and
effecting  the  possible  three-way  transaction and  engaged  the  law  firm of
Milbank, Tweed, Hadley & McCloy to advise it with respect thereto. As  described
in  greater detail  below, Salomon  Brothers, in  the course  of its engagement,
primarily performed  various  financial  analyses and  financial  due  diligence
regarding  each of  the parties. In  addition, Salomon  Brothers provided advice
regarding, and participated in discussions concerning, exchange ratios.  Salomon
Brothers  also  participated  from time  to  time in  discussions  regarding the
structure of  the transaction,  although  structural issues  were  predominantly
influenced  by  tax and  regulatory considerations.  In addition,  following the
August  23  meeting,  IPC  engaged  the  Deloitte  &  Touche  Consulting   Group
("Consulting  Group") to assist IPC's  management in identifying other potential
combination partners and  in assessing  the relative attractiveness  of each  of
these  potential partners,  including WPLH and  IES, from the  standpoint of the
potential synergies described by management which could be realizable from  such
a  transaction.  IPC  management,  with  the  assistance  of  Consulting  Group,
identified certain financial  factors, such as  financial strength and  earnings
growth,  and certain operational factors, such as customer mix and capacity mix,
that  would  be  relevant  to  the  IPC  Board's  assessment  of  the   relative
attractiveness  of other potential combination partners. This information, based
only on  publicly available  information and  certain attributes  regarding  the
financial  and operational profile of these potential partners, was presented to
the IPC Board to describe potential areas of synergies.
 
                                       36
<PAGE>
    On August 25,  1995, Mr. Protsch,  Mr. Root and  Mr. Chase met  to review  a
schedule  of due diligence requirements and the expansion of the confidentiality
agreement between  WPLH and  IES to  include  IPC, as  well as  the  prospective
timetable for a three-way transaction.
 
    On  August  30,  1995,  the  IES  Board  met  again  to  consider  strategic
alternatives, including the  possible combination  with WPLH,  or a  combination
with  WPLH  and  IPC.  At  this  meeting,  Arthur  Andersen  Economic Consulting
discussed the  changes  occurring  in  the electric  utility  industry  and  the
strategic  options  available for  electric utilities,  provided an  overview of
relevant factors  to  consider in  evaluating  mergers and  made  a  preliminary
presentation   in  which  it  analyzed,   based  solely  on  publicly  available
information and  using  a third  party  model  and assumptions  adopted  by  IES
management,   cost-savings  which  could  be  realized  from  various  strategic
alternatives, including combination transactions with WPLH and/or WPLH and  IPC.
The  results of  IES management's ongoing  due diligence were  also presented at
this meeting. The IES Board concluded that the most desirable transaction  would
likely  involve the three-way combination  of IES with WPLH  and IPC, but that a
two-way transaction with WPLH  alone also appeared  worthy of pursuit.  Although
the  IES Board decided  to pursue a  combination, the IES  Board also decided to
continue the reengineering initiative described above.
 
    The WPLH  Board met  on September  6, 1995  and was  updated by  management,
Merrill  Lynch and legal counsel  on the status of  the discussions with IES and
IPC and received  a comprehensive  due diligence  report on  IES. Legal  counsel
again   advised  the   WPLH  Board   with  respect   to  the   directors'  legal
responsibilities in connection with the proposed transaction. Merrill Lynch also
provided updated financial profiles and  preliminary valuations of IES and  IPC.
The WPLH Board again discussed the potential benefits to shareowners of WPLH (in
the  form of enhanced opportunities for earnings)  and customers of WPLH (in the
form of maintenance of  competitive rates) that could  result from the  proposed
two-way  or three-way combination and agreed that management should proceed with
its discussions with IES and IPC.
 
    On September 7, 1995, Mr.  Davis met Mr. Liu and  Jack R. Newman and  C.R.S.
Anderson,  outside directors of IES assigned to study and evaluate the potential
transaction, in Chicago, Illinois to  discuss various issues in connection  with
the  proposed business  combination and the  operations of  the combined company
after the combination.
 
    On September 11, 1995, Mr.  Protsch, Mr. Root and  Mr. Chase met to  discuss
the  general terms to be included in the merger agreement and to further discuss
the issues of management succession, the  composition of the board of  directors
of  the combined  company and  various utility  integration strategies.  At this
meeting, the three  executives also  reviewed the  status of  the due  diligence
process regarding WPLH and IES.
 
    On  September 14,  1995, the  IPC Board met  with IPC's  financial and legal
advisors to  discuss the  proposed combination  and various  other matters.  IPC
management  discussed  with the  IPC Board  management's  views on  the changing
conditions in  the electric  utility industry  generally, and  specifically  the
continued  consolidation within  the industry as  utilities prepared  for a more
competitive  environment.  Salomon   Brothers  reviewed  with   the  IPC   Board
preliminary  financial  profiles  and  preliminary  valuation  information  with
respect to  IES and  WPLH. Salomon  Brothers also  reviewed certain  preliminary
financial information regarding other potential merger candidates. Legal counsel
for  IPC advised the IPC Board with  respect to their legal responsibilities and
presented information as to the regulatory approvals that would be required  for
a  business combination involving  IPC generally and  specifically in connection
with a combination involving IES and WPLH, including the implications under  the
1935  Act. Counsel  also discussed  the various  implications of  combining with
entities (such as IES  and WPLH) that owned  and/or operated nuclear  generating
facilities  and the  various legal, regulatory  and environmental considerations
associated with nuclear generation. At that meeting, Consulting Group  discussed
with  the IPC Board, on behalf of IPC's management, the views of such management
as to various areas of operations in which potential synergies could be realized
following a combination with IES and WPLH and management's preliminary  analysis
of the scope
 
                                       37
<PAGE>
of such potential synergies. Consulting Group also discussed the potential areas
for  operational synergies that  could result from  combinations involving other
potential merger candidates. The IPC  Board discussed the potential benefits  to
stockholders  and customers that  could result from  the proposed combination as
well as combinations involving other  potential merger partners, and  authorized
management to proceed with the process.
 
    Following the September 14 IPC Board Meeting, IPC engaged Synergy Consulting
Services Corporation to conduct an analysis of the nuclear facilities of IES and
WPLH,  and WPLH,  IES and  IPC entered  into a  confidentiality agreement, which
superseded the confidentiality agreement previously entered into by and  between
WPLH  and  IES, pursuant  to  which the  parties  agreed to  exchange non-public
information with a view towards exploring a possible business combination. For a
description of certain standstill  provisions contained in such  confidentiality
agreement, see "The Merger Agreement -- Standstill Provisions."
 
    On September 19 and 20, 1995, Mr. Protsch, Mr. Ahearn, Mr. Fisher, Mr. Root,
Mr.  Stoppelmoor and Mr. Chase, together with other personnel from WPLH, IES and
IPC, as well as their  financial and legal advisors,  held the first full  scale
meeting  among all three  companies to discuss, among  other things, a timetable
for accomplishing the tasks required to negotiate, prepare and execute a  merger
agreement  among the three companies. Representatives of Consulting Group, which
firm had been retained to assist IPC's management, as described above, were also
present at such meeting. At these  meetings, due diligence was conducted by  the
managements  of WPLH,  IES and  IPC and  IPC representatives  were added  to the
working groups previously formed by WPLH and IES to examine more comprehensively
various  issues,   including  corporate   structure,  nonregulated   operations,
environmental  compliance and liabilities,  nuclear generation opportunities and
risks,  reengineering  initiatives  under  way  at  the  companies,   regulatory
considerations,   and  synergy  identification   and  quantification  approaches
relating thereto.  A decision  was also  made by  WPLH, IES  and IPC  to  engage
Consulting  Group to  assist the senior  managements of all  three companies and
certain  employees  designated  by  them  in  identifying  and  quantifying  the
potential  cost  savings from  synergies resulting  from the  proposed three-way
merger. The  scope  of  Consulting  Group's  engagement  (as  with  its  earlier
engagement  by IPC)  was limited  to assisting  such managements  and designated
employees in  the identification  and  quantification of  potential  combination
synergies,  including personnel reductions, non-labor savings, field operations,
electric dispatch, capacity deferral and  gas supply savings; the assessment  of
impacts  of  current stand-alone  cost  reduction initiatives  on merger-related
savings; quantification of costs to  achieve identified savings; and  developing
summary  presentation materials and supporting documentation. Managements of the
three companies were responsible for the assumptions and conclusions made in the
synergy study. While Consulting Group  assisted such managements in the  synergy
identification  and estimation  process, the determination  of synergy estimates
were the  sole  responsibility  of  the  managements  of  the  three  companies.
Consistent  with its assignment, Consulting Group  did not prepare any financial
projections, feasibility studies or reports, or assist the three companies  with
financial  evaluation or modeling of potential combination scenarios. Consulting
Group is a division of Deloitte & Touche LLP, an accounting firm that has  acted
as  independent auditors for IPC for many  years and that has received customary
fees for such services. Consulting  Group is a nationally recognized  consulting
firm  with experience in utility merger and acquisition transactions. Consulting
Group was selected by WPLH, IES and IPC based on its reputation, experience  and
expertise.  WPLH, IES and IPC will share equally the fees of Consulting Group in
connection with its assistance  to the managements of  the three parties,  which
will  be based on  time spent plus  expenses and are  estimated at $400,000. The
fees and expenses of Consulting Group incurred in connection with its assignment
with IPC exclusively  will be  borne exclusively by  IPC, and  are estimated  at
$100,000.  Consulting  Group has  also been  retained  by WPLH,  IES and  IPC to
provide expert testimony in  proceedings before regulatory commissions  relating
to approval of the Mergers.
 
    On  September 20,  1995, WPLH  management, Merrill  Lynch and  legal counsel
briefed the WPLH Board on the status of discussions with IES and IPC regarding a
business combination. Merrill Lynch reviewed its valuation methodology with  the
WPLH Board and management explained the structural,
 
                                       38
<PAGE>
nonregulated,  environmental,  nuclear,  reengineering,  regulatory  and synergy
analyses being undertaken and the  proposed timetable for their completion.  The
potential  benefits to shareowners and customers of WPLH were again discussed by
the WPLH Board.
 
    In the ten days following September  20, 1995, representatives of WPLH,  IES
and  IPC  continued  their  work with  respect  to  the  synergy identification,
nonregulated  operations,  environmental  compliance  and  liabilities,  nuclear
generation  opportunities and risks, reengineering  initiatives under way at the
companies, legal structure, regulatory plans and due diligence.
 
    Following a September  29, 1995  due diligence meeting  involving all  three
companies,  Mr. Davis, Mr. Protsch,  Mr. Liu, Mr. Root,  Mr. Stoppelmoor and Mr.
Chase met to  further discuss  the terms of  the proposed  merger agreement  and
various  other issues relating to  the potential three-way business combination,
such as management succession, board composition and various utility integration
strategies.
 
    On October 5, 1995, Arthur Andersen Economic Consulting made a  presentation
at  a meeting of the  IES Board that covered  strategic options in preparing for
competition and an  analysis of possible  cost savings from  both a two-way  and
three-way transaction involving WPLH and IPC as well as other possible strategic
combinations  and savings which might be obtained on a stand-alone basis. Arthur
Andersen Economic  Consulting's presentation  emphasized that  when  considering
merger  partners, the IES  Board should consider not  only possible cost savings
but also strategic  and qualitative differences.  The presentation also  covered
the  relative benefits of proceeding with a merger concurrent with or subsequent
to the reengineering  initiatives undertaken  by IES.  Arthur Andersen  Economic
Consulting's  analysis of possible cost savings  of the various combinations and
of IES on a stand-alone basis indicated that a three-way combination of IES with
WPLH and IPC would be expected to  result in the highest level of cost  savings.
Morgan  Stanley reviewed with the IES Board  the status of discussions with WPLH
and IPC and delivered to the IES Board its preliminary findings with respect  to
the  due diligence  conducted as of  such date  on WPLH and  IPC. Morgan Stanley
reviewed its valuation methodology  with the IES  Board and presented  financial
profiles  for  and preliminary  valuations  of each  of  WPLH and  IPC.  At this
meeting, the IES  Board concluded  that management should  pursue the  three-way
transaction  as the most desirable  from the perspective of  IES and its various
constituencies, recognizing  that in  so  doing, other  strategic  opportunities
might be foregone.
 
    During  the next several days, preliminary discussions occurred between WPLH
management and  Merrill  Lynch,  IES  management and  Morgan  Stanley,  and  IPC
management  and Salomon  Brothers, with respect  to negotiation  of the exchange
ratios, and between counsel for WPLH, counsel for IES and counsel for IPC,  with
respect  to the terms  of the draft  merger agreement and  the terms of possible
stock option agreements.
 
    On October 13, 1995, Messrs. Doyle, Root and Chase met with Consulting Group
to discuss the scope, costs and timetable of the synergy study undertaken by the
managements of the three companies with the assistance of Consulting Group. Over
the next several weeks, the working group from the three companies had  periodic
conversations  and met  with Consulting  Group to  finalize managements' synergy
analysis.
 
    On October 18,  1995, at a  regularly scheduled meeting  of the WPLH  Board,
WPLH  management, Merrill Lynch and legal counsel  updated the WPLH Board on the
overall progress of the merger negotiations with IES and IPC and the WPLH  Board
received  a full due  diligence report on IPC.  Merrill Lynch reviewed financial
and other information concerning WPLH, IES  and IPC. Management reported on  the
handling of various other issues relating to the transaction, such as management
succession,  the composition of  the board of directors  of the combined company
and  potential  utility  integration  strategies.  The  WPLH  Board  once  again
discussed the potential benefits to shareowners of WPLH (in the form of enhanced
opportunities for earnings) and customers of WPLH (in the form of maintenance of
competitive rates) that could result from the proposed three-way combination and
authorized management to continue negotiations with IES and IPC.
 
                                       39
<PAGE>
    On October 19, 1995, the IPC Board met with its legal and financial advisors
to  receive  an update  on the  status of  the merger  negotiations and  the due
diligence investigations of IES and WPLH.  Management reported to the IPC  Board
on  the overall status  of the merger  negotiations to date,  and management, in
conjunction with Consulting Group, discussed  with the IPC Board the  continuing
analysis  by the members  of the companies'  working group of  the areas for the
realization of potential operational synergies that IPC management had concluded
might result from  the proposed combination.  Salomon Brothers reviewed  certain
preliminary  financial and other information regarding IPC, IES, and WPLH. Legal
counsel presented a legal due diligence report on IES and WPLH and reviewed with
the  IPC  Board  the  proposed  handling  of  certain  issues  relating  to  the
combination,  including management succession,  the composition of  the board of
directors of  the combined  company, the  location of  the headquarters  of  the
utility subsidiaries of the combined company and employee related matters. Legal
counsel  also  reviewed the  proposed merger  structure and  certain significant
terms of  the  proposed  mergers. Synergy  Consulting  Services  Corporation,  a
nationally  recognized independent  nuclear energy  consultant retained  by IPC,
presented a report containing the results of its evaluation of the Duane  Arnold
Energy  Center  nuclear generating  facility of  Utilities  and of  the Kewaunee
nuclear facility of  WP&L and  identified and  characterized for  the IPC  Board
generic   nuclear  power  plant  business  risks.  Synergy  Consulting  Services
Corporation concluded that the Duane Arnold facility ranked above-average  among
the  industry's nuclear generating plants in all benchmarking categories, was in
good physical condition and was well  managed and also concluded that the  plans
for  decommissioning the  Duane Arnold  facility at the  end of  its useful life
appeared to be adequate assuming Utilities was successful in obtaining  approval
from  the  IUB for  a significant  increase in  its annual  decommissioning fund
allocation beginning in 1996. Synergy Consulting Services Corporation  concluded
that  the Kewaunee  facility has  historically been  one of  the best performing
plants within the nuclear industry and  noted that it had recently received  the
highest possible performance ratings from both the NRC and from the Institute of
Nuclear   Power   Operations  (INPO).   However,  Synergy   Consulting  Services
Corporation also noted that the Kewaunee facility is experiencing certain  steam
generator  tube  and  tube  sleeve degradation  that  potentially  threatens the
economic viability  of  continued  plant  operation  but  that  viable  economic
alternatives  to  this operational  problem  exist. Synergy  Consulting Services
Corporation also concluded that WP&L  management understood the financial  risks
associated  with the alternative  scenarios for the  Kewaunee facility's future,
that WP&L management had concluded that such risks were manageable and that  the
plans  for decommissioning the Kewaunee  facility at the end  of its useful life
were adequate.  In the  course of  its evaluation,  Synergy Consulting  Services
Corporation  reviewed  documentation  containing  relevant  operating statistics
(capacity factors,  production costs  and regulatory  performance) and  reviewed
external  performance evaluations  of the  Duane Arnold  and Kewaunee facilities
including INPO ratings, NRC Systematic Assessment of Licensee Performance (SALP)
ratings and other ratings based on publicly available industry benchmarking data
of nuclear  station performance.  The  Synergy Consulting  Services  Corporation
evaluation took into account specific risks associated with the Duane Arnold and
Kewaunee facilities in the following categories: production, costs, organization
and  management, and decommissioning plan.  Finally, Synergy Consulting Services
Corporation briefed the IPC Board on  the generic risks associated with  nuclear
generating plants, including premature permanent plant shutdown, temporary plant
shutdown,   uneconomic  plant   operation,  inability  to   extend  plant  life,
unanticipated costs, consequences of a nuclear accident, changes in regulations,
fuel storage  and  fuel  disposal  and  decommissioning  costs.  Following  such
presentations, the IPC Board once again discussed the various potential benefits
of  the proposed combination to IPC's  stockholders and customers and authorized
management to continue negotiations with IES and WPLH.
 
    The representatives and advisors  for all three companies  met and spoke  on
numerous  occasions over the  next three weeks,  finalizing managements' synergy
study, discussing the transaction and the related documentation and  negotiating
the  terms of  the Merger  Agreement, including  the conditions  to closing, the
termination provisions, the break-up fees, the covenants which would govern  the
operations  of WPLH, IES and  IPC prior to the  Effective Time and various other
policy matters that would  govern the operations of  the combined company  after
the Effective Time. These discussions
 
                                       40
<PAGE>
included meetings on November 1 and November 6, 1995 in New York among Edward M.
Gleason,  Vice President, Treasurer  and Corporate Secretary  of WPLH, Mr. Root,
Mr. Stoppelmoor and Mr. Chase, as well  as their legal counsel, to document  the
negotiated  terms  of  the  Merger Agreement  and  other  transaction documents.
Merrill Lynch, Morgan Stanley and Salomon Brothers held further discussions with
respect to the exchange ratios during the  week of November 5, 1995. During  the
course  of these discussions, Merrill Lynch, Morgan Stanley and Salomon Brothers
each formulated  a  range of  exchange  ratios  (but not  specific  ratios)  for
purposes  of the  ultimate negotiation  of the  specific exchange  ratios by the
parties, which ranges were then  communicated to each firm's respective  client.
While  the parties' financial  advisors discussed the  exchange ratios and their
respective client's positions with  respect thereto, the IES  Ratio and the  IPC
Ratio  were ultimately  determined by  each of  IES and  WPLH and  IPC and WPLH,
respectively.
 
    On November 7, 1995, at a special meeting of the IPC Board, IPC  management,
Salomon Brothers and legal counsel updated the IPC Board on the overall progress
of  the merger negotiations with WPLH and IES. Counsel to IPC outlined in detail
the terms and conditions of the then current forms of the Merger Agreement,  the
Stock  Option Agreements  and the  Employment Agreements.  Counsel reviewed such
matters as the covenants that would govern the operations of the companies prior
to the  Effective  Time, the  representations  and  warranties of  each  of  the
companies,  the conditions  to consummation of  the Mergers  and the termination
provisions of  the Merger  Agreement  (including the  termination fees  and  the
operation  of the  Stock Option Agreements).  The IPC Board  also discussed with
management, counsel and Salomon Brothers the management succession plan outlined
in the Merger  Agreement, the  composition of  the Interstate  Energy Board  and
potential  integration strategies. Consulting Group assisted IPC management in a
further presentation to the IPC Board where management reported on the  analyses
of  WPLH,  IES and  IPC managements  of  the potential  synergies that  could be
achieved by a  combination of  the three companies.  This presentation  reviewed
assumptions  underlying managements' analyses, gave an  overview of the types of
synergies (financial, regulatory and  operational) that could  be achieved by  a
three-way  combination  and emphasized  that the  identified synergies  were all
directly related to a possible merger and did not include other types of savings
that might be achieved without a merger. An overview of categories of  synergies
was  given  which  identified  the  following  areas  for  potential  synergies:
corporate and  support  labor,  corporate programs,  electric  production,  fuel
transportation,  gas supply  costs and  purchasing economies  for items  such as
materials, supplies  and contract  services. The  analyses assumed  a period  of
1997-2006,  that  the  combination would  result  in a  utility  holding company
registered under the 1935  Act, that management  and operational integration  of
corporate,  distribution and  production support  functions would  occur without
total physical centralization, that labor savings would be achieved by a variety
of methods,  including attrition,  controlled  hiring and  voluntary  separation
programs  over three years following the  combination, and that costs to achieve
the savings would be incurred primarily over the first three years following the
combination. Based  upon  the information  compiled  through November  7,  1995,
managements'   analyses,  as   reported  to   the  IPC   Board,  estimated  that
approximately $780 million in potential synergy savings were realizable over the
assumed ten-year period, with the cost  to achieve such savings estimated to  be
approximately  $80 million, resulting in  managements' estimate of approximately
$700 million of net anticipated synergy savings as a result of the Mergers  over
the  assumed  ten-year  period.  The  analyses  employed  in  order  to  develop
managements' estimates of potential savings as a result of the Mergers  utilized
information  provided by  each company and  were based  upon various assumptions
that involve judgments with respect to, among other things, future national  and
regional   economic  and  competitive  conditions,  technological  developments,
inflation rates,  regulatory  treatment, weather  conditions,  financial  market
conditions,  future business decisions and other uncertainties, all of which are
difficult to predict and many  of which are beyond the  control of IPC, IES  and
WPLH.
 
    At  the  November  7 meeting,  the  IPC  Board also  discussed  with Salomon
Brothers various financial analyses prepared by Salomon Brothers with respect to
each of IPC, WPLH and IES. The IPC Board again discussed the potential  benefits
of  the proposed  three-way combination  to IPC stockholders  (in the  form of a
premium for their shares  and enhanced opportunities  for earnings and  dividend
growth)  and to customers of IPC (in  the form of maintenance of quality service
and competitive rates). At the
 
                                       41
<PAGE>
conclusion of the  November 7 meeting,  the IPC Board  authorized management  to
pursue  finalization of the Merger Agreement and the other transaction documents
with WPLH and IES and to negotiate an exchange ratio for IPC Common Stock within
a specified range determined by the IPC Board.
 
    On November 9, 1995, discussions were held among Mr. Davis, Mr. Liu and  Mr.
Stoppelmoor  and  among  Merrill  Lynch,  Morgan  Stanley  and  Salomon Brothers
regarding the exchange ratios to be applied  to IES Common Stock and IPC  Common
Stock.  After consulting and reviewing with  Merrill Lynch the range of exchange
ratios previously presented by Merrill Lynch and discussed with the WPLH  Board,
as  well as  the discussions  among the  companies and  their financial advisors
regarding the exchange ratios,  WPLH management proposed ratios  to IES and  IPC
which  would result in each share of  WPLH Common Stock remaining outstanding as
one share of  Interstate Energy  Common Stock, each  share of  IES Common  Stock
being  converted into 0.98  a share of  Interstate Energy Common  Stock and each
share of IPC Common Stock being converted into 1.11 shares of Interstate  Energy
Common Stock.
 
    As  a result of these discussions,  Mr. Stoppelmoor determined to present to
IPC's Board WPLH's proposed exchange ratio  of 1.11 shares of Interstate  Energy
Common  Stock for each  share of IPC  Common Stock. This  determination was made
based upon the fact that this exchange  ratio was within the range specified  by
IPC's Board at the November 7, 1995 meeting and was subject to the understanding
of  Salomon Brothers and  Mr. Stoppelmoor that the  exchange ratio proposed with
respect to IES would be  0.98 of a share of  Interstate Energy Common Stock  for
each share of IES Common Stock.
 
    On  November 10, 1995,  at a special  meeting of the  WPLH Board, counsel to
WPLH outlined in detail the  terms and conditions of  the final forms of  Merger
Agreement,  Stock Option Agreements, Employment Agreements and other transaction
documents. Counsel reviewed such matters  as the representations and  warranties
of  each of the companies, the conditions to consummation of the Mergers and the
termination provisions of the Merger  Agreement (including the termination  fees
and  the operation  of the Stock  Option Agreements). Counsel  also reviewed the
succession plan outlined in the Merger Agreement and the handling of the various
other issues relating to the transactions, such as the composition of the  board
of  directors of  the combined company.  Mr. Protsch, A.J.  (Nino) Amato, Senior
Vice President of  WP&L, Mr.  Doyle, Ms. Swan  and Mr.  Gleason made  management
presentations  to the WPLH Board, including an updated report on the analysis of
potential synergies prepared by the managements  of WPLH, IES and IPC, with  the
assistance  of Consulting  Group, which  included discussions  of potential cost
savings from  economies  of scale  and  decreased electric  production  and  gas
purchase  costs and  elimination of  duplicative administrative  expenses, and a
review of the regulatory  plan and the completion  of the overall due  diligence
process.  Legal counsel and management then  described the covenants which would
govern the operations of WPLH, IES and IPC prior to the Effective Time and other
policy issues which would govern the operations of the combined company and  its
subsidiaries  subsequent  to the  Effective Time.  At  the November  10 meeting,
Merrill Lynch delivered its written opinion to  the WPLH Board that, as of  such
date  and based upon and subject to the matters discussed, the proposed exchange
ratios of 0.98 of  a share of  Interstate Energy Common Stock  per share of  IES
Common  Stock and 1.11 shares of Interstate Energy Common Stock per share of IPC
Common Stock were fair to  WPLH from a financial point  of view. The WPLH  Board
discussed  the presentations  they had received  at this and  various other WPLH
Board Meetings and, upon conclusion,  unanimously approved the Merger  Agreement
and the Stock Option Agreements and authorized their execution.
 
    On  November 10, 1995,  at a regularly  scheduled meeting of  the IES Board,
counsel to IES  presented in  detail the terms  and conditions  of the  proposed
Merger  Agreement,  Stock  Option Agreements,  Employment  Agreements  and other
transaction documents. Arthur Andersen  Economic Consulting made a  presentation
summarizing  various financial data of the  merger candidates and IES, including
retail price per Kwh and sales volume growth, and emphasizing that factors to be
considered in  evaluating  a  merger candidate  include  management  capability,
regulatory  issues  (including  past  regulatory  performances,  stranded  asset
exposure and complexities of multi-state  operations) and cultural factors.  The
Arthur  Andersen Economic  Consulting presentation  also generally  reviewed two
 
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<PAGE>
strategic options  available  for  electric utilities  responding  to  increased
competition:  1) consolidation or  merger; and 2)  process reengineering. Arthur
Andersen Economic Consulting analyzed for  IES cost savings that could  possibly
be realized from four different hypothetical merger combination transactions and
through  process reengineering on a stand-alone basis. The cost savings analyses
were based solely on publicly available  information and were developed using  a
third-party  model and  assumptions, including industry  benchmarks developed in
conjunction with and  adopted by IES  management. In addition  to the  principal
approach using the third-party model, two additional methodologies were utilized
to  substantiate  the  reasonableness  of the  principal  approach:  the average
preliminary  comparison  method  and  the  statistical  econometric   regression
estimation  methodology. Both of these  secondary methodologies utilize publicly
available data gleaned  from recently  announced or  completed electric  utility
mergers.  The cost savings analyses of the four possible merger combinations and
of IES on a  stand-alone basis pursuing process  reengineering indicated that  a
three-way  combination of IES and WPLH and IPC might result in the highest level
of cost savings. Because these analyses were based solely on publicly  available
data  without input from nonpublic information from the various potential merger
candidates, Arthur  Andersen Economic  Consulting stressed  that these  analyses
could  not be relied  on to definitively rank  the alternatives. Although Arthur
Andersen Economic Consulting reviewed  various potential transactions, the  firm
made  no recommendation to the IES Board as  to whether or not to proceed with a
merger or who to select as a merger partner. Morgan Stanley rendered to the  IES
Board  an oral  opinion to  the effect that,  at such  date, and  based upon the
procedures and subject to the assumptions stated at the meeting, the IES  Ratio,
taking  into account the IPC  Ratio, was fair from a  financial point of view to
the holders of IES Common Stock. The IES Board discussed the presentations  they
had  received at this and other IES Board meetings and, upon conclusion, the IES
Board members present at the  meeting unanimously approved the Merger  Agreement
and the Stock Option Agreements and authorized their execution.
 
    On  November 10, 1995, at a special meeting of the IPC Board, counsel to IPC
reviewed with the IPC Board  the terms of the  final forms of Merger  Agreement,
Stock  Option Agreements, Employment Agreements and other transaction documents.
Counsel also reviewed the approval process to be commenced upon execution of the
Merger  Agreement,  including  the  process  of  seeking  the  approval  of  IPC
stockholders  and  the  various  regulatory  agencies  whose  approval  would be
required. Counsel also discussed  with the IPC board  various provisions of  the
1935  Act and their applicability to the  proposed Mergers and to the operations
of the combined  entity after the  Effective Time. At  the November 10  meeting,
Salomon  Brothers delivered its written  opinion to the IPC  Board to the effect
that, as of such date and based  upon and subject to various considerations  set
forth  in such opinion, the proposed exchange ratio of 1.11 shares of Interstate
Energy Common  Stock  for each  share  of IPC  Common  Stock was  fair,  from  a
financial  point of view, to  the holders of IPC  Common Stock (other than WPLH,
IES or any  of their respective  affiliates). The IPC  Board then discussed  the
presentations  they had  received at this  and various other  IPC Board meetings
and, upon conclusion, unanimously  approved the Merger  Agreement and the  Stock
Option  Agreements  and the  transactions  contemplated thereby,  and authorized
their execution. Following the meetings of the WPLH Board, the IES Board and the
IPC Board, the Merger Agreement and the Stock Option Agreements were executed.
 
    In mid-April 1996, Morgan Stanley, on behalf of IES, contacted Merrill Lynch
and informed Merrill Lynch that IES desired to discuss certain issues  regarding
the Merger Agreement and specifically IES's investment in McLeod. Morgan Stanley
noted  that the  potential value of  IES's stake  in McLeod might  be above that
contemplated at  the  time  the  parties  originally  entered  into  the  Merger
Agreement.
 
    As  of  the  date hereof,  IES  Investments Inc.,  an  indirect wholly-owned
subsidiary of IES, holds 8,420,457 shares of McLeod Class B common stock  (which
is  convertible at  the option  of IES  into McLeod  Class A  common stock  on a
share-for-share basis) and  vested options to  purchase an additional  1,300,688
shares.  In  the  McLeod  initial public  offering,  IES  Investments  Inc. also
purchased 500,000 shares of Class A common  stock. The rights of McLeod Class  A
common  stock and Class  B common stock are  substantially identical except that
Class A common stock has 1 vote per share and
 
                                       43
<PAGE>
Class B common stock has 0.40 votes per share. Mr. Liu is a director of  McLeod,
owns 7,450 shares of Class A common stock and has a currently exercisable option
to purchase 32,813 shares of Class A common stock of McLeod.
 
    IES  Investments Inc.  purchased the  McLeod Class  B common  stock in three
blocks commencing in April 1993, for  an aggregate of $9.2 million. The  options
are exercisable for approximately $2.3 million in the aggregate. IES Investments
Inc.  paid $10.0 million  for the Class  A common stock  purchased in the McLeod
initial public offering.
 
    Following the passage of the Telecommunications Act of 1996, in April  1996,
McLeod  filed a registration statement  with the SEC with  respect to an initial
public offering of its Class A common stock. On June 14, 1996, McLeod sold  13.8
million  shares of its Class  A common stock in an  initial public offering at a
price to the  public of $20  per share. On  such date, the  last sale price  per
share  of the  McLeod Class  A common  stock on  the Nasdaq  National Market was
$25.50.  McLeod,   a   provider   of  integrated   local   and   long   distance
telecommunications  services to  small and medium-sized  businesses primarily in
Iowa and Illinois, reported  a net loss  of $11.3 million  on revenues of  $29.0
million for the fiscal year ended December 31, 1995. IES did not sell or convert
any  of its  shares of  Class B  common stock  of McLeod  in the  initial public
offering, but purchased $10 million of McLeod Class A common stock as a part  of
the  public offering transaction.  IES is also subject  to an Investor Agreement
executed on April 1, 1996  with McLeod pursuant to which  IES has agreed, for  a
two-year  period  which commenced  on  June 10,  1996,  not to  sell  any equity
securities of McLeod unless otherwise approved by the McLeod Board of Directors.
 
    On April 19, 1996,  prior to the consummation  of the McLeod initial  public
offering,  Morgan Stanley, on  behalf of IES,  proposed that the  ratio at which
shares of IES Common Stock would  be converted into shares of Interstate  Energy
Common  Stock be  adjusted to  provide IES  shareholders with  two-thirds of the
after-tax gain of IES's investment in McLeod, assuming that McLeod completed its
initial public  offering and  that  IES constructively  sold its  investment  in
McLeod  within a period immediately prior  to consummation of the Mergers. Under
the IES proposal,  the after-tax  gain associated  with a  constructive sale  of
IES's interest in McLeod and the value of additional shares of Interstate Energy
Common  Stock to be issued to holders of  IES Common Stock would have been based
on the market value of McLeod common shares within a period immediately prior to
the consummation of the  Mergers. Following discussions  with its financial  and
legal  advisors, management  of WPLH  indicated that  WPLH did  not consider the
modification of the  IES exchange  ratio as proposed  by IES  to be  appropriate
based  in part upon the  contingent nature of IES's  investment in McLeod. IPC's
management concurred with the position adopted by WPLH.
 
    On May 1, 1996, Morgan Stanley delivered to Merrill Lynch a revised proposal
from IES to provide for an adjustment of the IES exchange ratio. The revised IES
proposal provided  that  the IES  exchange  ratio  be increased  to  provide  an
additional  $25 million  of Interstate Energy  Common Stock  to IES shareholders
contingent upon  McLeod  completing an  initial  public offering  prior  to  the
consummation of the Mergers. As proposed by IES, the number of additional shares
of Interstate Energy Common Stock to be issued in the event McLeod completed its
initial  public offering as described above would  be based on the trading price
of the WPLH Common Stock  in the ten trading days  prior to the execution of  an
amendment to the Merger Agreement.
 
    After  consulting with  members of the  WPLH Board and  WPLH's financial and
legal advisors regarding the revised IES  proposal, Mr. Davis contacted Mr.  Liu
and informed him that WPLH management would be prepared to recommend to the WPLH
Board  a proposal that would  increase the IES exchange  ratio from 0.98 to 1.01
provided that, prior to  the consummation of the  Mergers, McLeod completed  its
initial  public offering generally  as described in its  initial filing with the
SEC and at a price per share greater than or equal to $13.00. During this  time,
Mr. Davis also had periodic conversations with Mr. Stoppelmoor regarding the IES
proposals and IPC's position regarding an amendment to the Merger Agreement. The
financial  advisors for both WPLH and IPC also discussed matters relating to the
amendment and  IPC's views  with respect  thereto. Following  these  discussions
 
                                       44
<PAGE>
and  further consultations with members of their respective Boards and financial
and legal advisors, Messrs.  Davis, Liu and Stoppelmoor  agreed to recommend  to
their Boards approval of an amendment to the Merger Agreement that would include
a  provision increasing the  IES exchange ratio  from 0.98 to  1.01 in the event
McLeod completed  an initial  public offering  within the  parameters  described
above prior to the consummation of the Mergers.
 
    On  May 7, 1996, the IES Board  approved in principle the proposed amendment
to the Merger Agreement. The IES Board, in attempting to determine the potential
value to the IES shareholders of  the McLeod holdings, estimated that IES  could
have  realized a  potential pre-tax  gain of  $152 million  if IES  were able to
participate in the McLeod initial public offering and realize a sale price equal
to $17 per share, the midpoint  of McLeod's then disclosed offering price  range
(assuming  the exercise of all options vested  as of June 30, 1996). In deciding
to accept the  revised IES Ratio,  the IES Board,  after discussion with  Morgan
Stanley,  considered, among  other factors (i)  the taxes which  would likely be
payable by  IES upon  the eventual  sale of  its McLeod  common stock  once  the
aforementioned  restrictions  on transfer  had lapsed,  (ii)  the fact  that, in
valuing IES Common Stock, the market  would significantly discount the value  of
McLeod  due to lack of earnings and  to the underlying volatility which would be
inherent  in  the  publicly-traded  McLeod  Class  A  common  stock,  given  the
difference in industry fundamentals and anticipated shareholder profiles between
McLeod  and  IES, (iii)  the  illiquidity of  the IES  stake  in light  of IES's
restrictions on transfer, and (iv) the fact that with the adjusted 1.01 exchange
ratio, IES shareholders, through their pro forma ownership of Interstate Energy,
would effectively retain approximately  42% of the  value attributable to  IES's
ownership of McLeod shares.
 
    On  May 7,  1996, at a  special meeting of  the WPLH Board,  counsel to WPLH
described the proposed amendment to the Merger Agreement and discussed with  the
WPLH Board the impact the proposed amendment would have on various provisions of
the Merger Agreement. At this meeting, Merrill Lynch also discussed and reviewed
with the WPLH Board the proposed contingent adjustment to the IES Ratio relating
to  the  McLeod Contingency  and orally  confirmed that  Merrill Lynch  would be
prepared to render an opinion to the effect that, based on the assumptions made,
matters considered and limits of review as set forth in such opinion, the Ratios
(including the IES Ratio as adjusted if the McLeod Contingency is satisfied) are
fair to WPLH from a financial point of view. After considering the presentations
made and the matters  discussed at the  special meeting, the  WPLH Board by  the
directors  present  unanimously approved  the proposed  amendment to  the Merger
Agreement and authorized the execution thereof.
 
    On May 10, 1996, the IPC Board met with its financial and legal advisors  to
discuss  and vote  upon the  proposed amendment  to the  Merger Agreement. IPC's
legal advisors described the proposed amendment to the IPC Board, and  discussed
with  the  IPC  Board various  applicable  provisions of  the  Merger Agreement.
Salomon Brothers reviewed with the IPC Board the proposed contingent  adjustment
to  the IES Ratio relating  to the McLeod Contingency  and advised the IPC Board
that if the proposed  amendment were adopted, Salomon  Brothers could render  an
opinion  to the  effect that, based  upon and subject  to various considerations
that would be  set forth  in such opinion,  as of  May 10, 1996,  the IPC  Ratio
(assuming  the IES Ratio is adjusted for satisfaction of the McLeod Contingency)
is fair to the holders of IPC Common Stock (other than WPLH, IES or any of their
respective affiliates) from  a financial  point of view.  After considering  the
presentations  made  and the  matters discussed  at the  meeting, the  IPC Board
unanimously  approved  the  proposed  amendment  to  the  Merger  Agreement  and
authorized the execution thereof.
 
    The amendment to the Merger Agreement was executed by the parties on May 22,
1996.
 
    On  June  14, 1996,  McLeod completed  its initial  public offering  and the
McLeod Contingency was satisfied. As a  result, the IES Ratio was  automatically
adjusted to 1.01.
 
                                       45
<PAGE>
REASONS FOR THE MERGERS; RECOMMENDATIONS OF THE BOARDS OF DIRECTORS
 
    WPLH,  IES and IPC believe that  the Mergers offer the following significant
strategic and  financial  benefits  to  each company  and  to  their  respective
shareowners, as well as to their employees and customers:
 
    -  MAINTENANCE  OF  COMPETITIVE  RATES  -- Interstate  Energy  will  be more
       effective in  meeting  the  challenges of  the  increasingly  competitive
       environment in the utility industry than any of WPLH, IES or IPC standing
       alone  due to the economies of  scale available to Interstate Energy. The
       impact of these economies of scale, which are described in greater detail
       below, will help to position  Interstate Energy to deal effectively  with
       increased competition with respect to rates. The Mergers, by creating the
       potential  for increased economies of  scale, will create the opportunity
       for strategic, financial  and operational benefits  for customers in  the
       form  of more competitive rates over the long term and for shareowners in
       the form of greater financial strength and financial flexibility.
 
    -  INTEGRATION OF  CORPORATE  AND  ADMINISTRATIVE  FUNCTIONS  --  Interstate
       Energy  will be able to  consolidate certain corporate and administrative
       functions  of  WPLH,  IES   and  IPC,  thereby  eliminating   duplicative
       positions, reducing other non-labor corporate and administrative expenses
       and  limiting or avoiding duplicative expenditures for administrative and
       customer service  programs and  information systems.  A joint  transition
       task  force is examining the manner in  which to best organize and manage
       the businesses of Interstate Energy and identify duplicative positions in
       the corporate  and administrative  areas. It  is anticipated  that, as  a
       result  of combining  staff and  other functions,  Interstate Energy will
       have somewhat fewer employees within several years than WPLH, IES and IPC
       currently have  in the  aggregate. WPLH,  IES and  IPC are  committed  to
       achieve  cost  savings  in  the  area  of  personnel  reductions  through
       attrition, strictly controlled  hiring, and  reassignment and  retraining
       and,  to  the extent  required, severance  and targeted  early retirement
       programs. In  addition,  some savings  in  areas such  as  insurance  and
       regulatory  costs and legal, audit and consulting fees are expected to be
       realized.
 
    -  REDUCED OPERATING COSTS  -- The  combination should  result in  decreased
       electric  production  costs through  the joint  dispatch of  the systems.
       Natural  gas  supply  savings   through  combined  purchasing  are   also
       anticipated.
 
    -  PURCHASING  ECONOMIES AND STREAMLINING OF  INVENTORIES -- The combination
       of the  three companies  should result  in greater  purchasing power  for
       items   such  as  fuel  and   transportation  services  and  general  and
       operational goods  and services,  and the  reduction of  inventories  for
       standardized  materials  and  supplies for  construction,  operations and
       maintenance within the combined generation, transmission and distribution
       systems.
 
    -  COORDINATION OF  DIVERSIFICATION  PROGRAMS  -- WPLH  and  IES  each  have
       significant   non-utility  subsidiaries,  and  Interstate  Energy,  as  a
       stronger financial  entity, should  be  able to  manage and  pursue  such
       subsidiary  businesses  more efficiently  and  effectively. WPLH  and IES
       currently engage in a number of diversified businesses, some of which are
       complementary. To the extent  such complementary businesses are  combined
       and  able to collaborate in the pursuit of market opportunities, benefits
       from economies  of  scale should  be  obtained and  thereby  improve  the
       performance  of these businesses. Furthermore,  due to the larger capital
       base of  Interstate  Energy,  the financial  flexibility  will  exist  to
       support the existing businesses as well as take advantage of new business
       opportunities as they arise.
 
    -  MORE  DIVERSE SERVICE  TERRITORY --  The combined  service territories of
       WP&L, Utilities and IPC will be larger  and more diverse than any of  the
       service  territories of WP&L,  Utilities or IPC  as independent entities.
       This increased customer and geographical diversity is expected to  reduce
       the  exposure to changes in  economic, competitive or climatic conditions
       in any given sector of the combined service territory.
 
                                       46
<PAGE>
    -  EXPANDED MANAGEMENT RESOURCES -- In  combination, WPLH, IES and IPC  will
       be  able  to draw  on a  larger  and more  diverse mid-  and senior-level
       management pool  to lead  Interstate Energy  forward in  an  increasingly
       competitive  environment for the delivery of  energy and should be better
       able to attract and retain the most qualified employees. The employees of
       Interstate Energy  should  also benefit  from  new opportunities  in  the
       expanded organization.
 
    Subject  to the  qualifications expressed below,  WPLH, IES  and IPC believe
that synergies  from  the Mergers  will  generate substantial  cost  savings  to
Interstate  Energy, which  would not be  available absent  the Mergers. Although
there can be no assurances that such results will be achieved, current estimates
by the managements of WPLH, IES and  IPC indicate that the Mergers could  result
in  potential net  cost savings  (that is, after  taking into  account the costs
incurred to  achieve such  savings)  of approximately  $749 million  during  the
ten-year  period following the  Mergers. Approximately 45%  of these savings are
expected to be achieved through personnel reductions involving approximately 600
positions. Other potentially significant cost savings include reduced  corporate
and   administrative  programs,  reduced   electric  production  costs,  nonfuel
purchasing economies,  lower gas  supply  costs, and  other avoided  or  reduced
operation  and maintenance costs, such as  the deferral of costs associated with
adding new generating capacity.
 
    Any actual savings in costs are  expected through the regulatory process  to
inure  to the benefit of both shareowners  and ratepayers. The allocation of the
benefits and cost savings  among shareowners and ratepayers  will depend on  the
results  of regulatory proceedings  in the various  jurisdictions in which WPLH,
IES and IPC operate their businesses. See "Regulatory Matters."
 
    The foregoing  discussion contains  forward looking  statements,  including,
without  limitation, mangements' estimates of potential net cost savings. Actual
results might  differ materially  from those  contained in  the forward  looking
statements.  The analyses employed in order to develop managements' estimates of
potential savings as a result of the Mergers were necessarily based upon various
assumptions that involve judgments with  respect to, among other things,  future
national   and  regional  economic  and  competitive  conditions,  technological
developments,  inflation  rates,   regulatory  treatment,  weather   conditions,
financial market conditions, future business decisions, and other uncertainties,
all  of which are difficult to predict and  many of which are beyond the control
of WPLH, IES and  IPC. Accordingly, while  WPLH, IES and  IPC believe that  such
assumptions  are  reasonable for  purposes of  the  development of  estimates of
potential savings,  there  can  be  no  assurance  that  such  assumptions  will
approximate actual experience or that such savings will be realized.
 
    The  WPLH Board, the IES Board and  the IPC Board each considered the impact
of Interstate Energy  registering as  a holding company  under the  1935 Act  in
connection  with the Mergers.  Based on the benefits  that each company believes
will be  derived from  the  Mergers, the  potential detriments  associated  with
Interstate  Energy operating  as a  registered holding  company were  not deemed
material. See  "Regulatory Matters  --  Public Utility  Holding Company  Act  of
1935."
 
    WPLH.   The WPLH Board  believes that the terms of  the Mergers are fair to,
and in the best  interests of, WPLH and  its shareowners. Accordingly, the  WPLH
Board,  by  a  unanimous  vote,  has  approved  the  Merger  Agreement  (and the
transactions contemplated thereby) and recommends  its approval and adoption  by
WPLH's  shareowners.  The  WPLH  Board believes:  that  WPLH's  shareowners will
benefit by participation in the combined economic growth of the WP&L,  Utilities
and  IPC service territories, and from the inherent increase in scale economies,
the market diversification and the  resulting increased financial stability  and
strength;  that the Mergers will result  in cost savings from decreased electric
production and  gas  supply costs,  a  reduction in  operating  and  maintenance
expense  and other factors discussed above; and that the combined enterprise can
more effectively  participate in  the increasingly  competitive market  for  the
generation of power. All of these factors offer a potential increase in earnings
and the creation of a larger, financially stronger company.
 
                                       47
<PAGE>
    In  reaching its  conclusions, the WPLH  Board considered  (i) the financial
performance, condition, business operations and  prospects of each of WPLH,  IES
and  IPC and that, on  a combined basis, the  companies will likely have greater
financial stability and strength due  to participation in the combined  economic
climate  and growth of each of the  WP&L, Utilities and IPC service territories,
the inherent increase in scale  economies, the market diversification  resulting
from the combination of customer bases and the impact of the potential operating
efficiencies  and other synergies  which are expected  to reduce operational and
maintenance expenses,  as more  fully discussed  above; (ii)  current  industry,
economic,  market  and regulatory  conditions  which encourage  consolidation to
reduce risk and create new avenues for earnings growth (as discussed under  "The
Mergers  -- Background  of the Mergers"  above); (iii)  the anticipated positive
effect of the  Mergers on  shareowners and  customers (as  more fully  discussed
above); (iv) the terms of the Merger Agreement, the Stock Option Agreements, the
Employment  Agreements  and  other  documents executed  and  to  be  executed in
connection with the  Mergers which  provide for  reciprocal representations  and
warranties, conditions to closing and rights to termination, balanced rights and
obligations and protection for employees of WPLH (as discussed under "The Merger
Agreement,"  "The Stock Option Agreements"  and "-- Employment Agreements"); (v)
the management  succession  plan  specified  in the  Merger  Agreement  and  the
Employment Agreements of Messrs. Liu, Davis, Stoppelmoor and Chase (as described
under "-- Employment Agreements" and "Interstate Energy Following the Mergers --
Management of Interstate Energy") which provides a prudent plan for managing the
integration of and transition in management; (vi) the impact of regulation under
various  state and federal laws (as described under "Regulatory Matters" and "--
Background of the Mergers"); (vii) that  the Mergers are expected to be  treated
as  a  tax-free reorganization  to  shareowners and  to  be accounted  for  as a
pooling-of-interests transaction (which avoids  the reduction in earnings  which
would  result  from the  creation and  amortization  of goodwill  under purchase
accounting) (as discussed under "-- Certain Federal Income Tax Consequences" and
"-- Accounting Treatment"); and (viii)  the opinion of Merrill Lynch,  described
below,  that the  Ratios are  fair to WPLH  from a  financial point  of view. In
determining that  the Mergers  are fair  to and  in the  best interests  of  its
shareowners,  the WPLH Board considered the above factors as a whole and did not
assign specific or relative weights to any one factor or group of factors.
 
    The  WPLH  Board  did,  however,  consider  several  countervailing  factors
associated  with the Mergers.  The first factor  related to Utilities' ownership
and operation of the Duane Arnold Energy Center, which is a 520 MW boiling water
reactor nuclear power plant. The WPLH  Board considered the fact that  Utilities
was  a  70% owner  of  the plant  and that  this  plant provided  Utilities with
approximately 18% of its generating capacity and 25% of its energy requirements.
Comparable to the Kewaunee Nuclear facility (of  which WP&L is a part owner)  in
terms  of its licensed life,  the Duane Arnold facility had  a net book value in
the fall of 1995  of approximately $300  million. Available estimates  suggested
that  the  facility  faced  a decommissioning  liability  of  approximately $361
million (in  1993  dollars)  of  which  Utilities  is  responsible  for  70%  or
approximately  $253 million, with approximately $34 million (at the end of 1994)
thereof accumulated in an external trust fund and approximately $21 million  (at
the  end of  1994) thereof  accumulated in an  internal reserve.  The WPLH Board
considered this as a potential  negative factor associated with the  combination
due  to the uncertainty  surrounding whether the Duane  Arnold facility would be
well-positioned to operate  as a  competitive power production  facility in  the
event  that  the  generation segment  of  the electric  utility  industry became
substantially unregulated  and fully  competitive.  The question  presented  was
whether there was likely to be material financial risk in such a circumstance in
the form of potential stranded investment.
 
    The  potential negative  impact of the  Duane Arnold facility  was offset by
various other  factors.  First,  the  WPLH  Board  believes,  based  on  ongoing
proceedings  at FERC,  that federal policymakers  will ultimately  allow for the
recovery of stranded investment in the event that policies are implemented which
bring about greater competition in the generation sector of the electric utility
industry. Second, all available information led to the conclusion that the Duane
Arnold facility  was a  well-operated and  well-managed nuclear  facility  whose
costs  were generally more favorable than those  of most nuclear plants in North
America. Third, historical regulatory experiences in Iowa presented no  evidence
that  unreasonable regulatory  ratemaking policies  would likely  be implemented
with respect to that facility.
 
                                       48
<PAGE>
    A second concern considered  by the WPLH Board  related to the ownership  by
Utilities  and IPC of former manufactured  gas plant sites for which remediation
costs will be incurred over time. Utilities owns or may have responsibility  for
remediation  for 34  such sites  while IPC owns  or may  have responsibility for
remediation  for  nine  such  sites.  With  respect  to  the  Utilities   sites,
information  available  to the  WPLH Board  suggested  that while  the potential
magnitude of remaining clean-up costs was significant (approximately $37 million
based on then current estimates), Utilities had a well-established track  record
of  effectively investigating and remediating  its former manufactured gas plant
sites and of seeking  and receiving favorable regulatory  rate treatment in  the
State  of  Iowa for  the  costs incurred  in those  efforts.  With respect  to a
majority of the sites, IPC was found to be in the early stages of evaluating its
manufactured gas plant obligations and potential financial exposures. As of  the
fall of 1995, IPC had received favorable regulatory rate treatment in the States
of Iowa and Illinois with respect to costs incurred to date in the investigation
of  its former manufactured  gas plant sites.  In connection with  the IPC sites
located in Minnesota, a  decision on rate  recovery was then  pending in a  rate
case  and the WPLH Board did not rely  on the potential for full or partial rate
recovery (or the timing thereof) in analyzing the Mergers.
 
    Although the WPLH Board  considered the foregoing  factors in approving  the
Mergers,  due to the beneficial aspects of the Mergers described above, the WPLH
Board concluded that the unfavorable aspects  of the Mergers were outweighed  by
the positive impacts and potential opportunities.
 
    THE  WPLH BOARD BY THE DIRECTORS PRESENT HAS UNANIMOUSLY APPROVED THE MERGER
AGREEMENT AND BELIEVES THAT  THE TERMS OF  THE MERGERS ARE FAIR  TO, AND IN  THE
BEST  INTERESTS OF,  WPLH'S SHAREOWNERS, HAS  APPROVED EACH OF  THE WPLH CHARTER
AMENDMENTS, SUPPORTS THE ELECTION OF  THE NOMINATED WPLH DIRECTORS AND  SUPPORTS
THE  APPOINTMENT OF ARTHUR  ANDERSEN LLP AS WPLH'S  INDEPENDENT AUDITORS FOR THE
YEAR ENDING DECEMBER 31, 1996. THE WPLH BOARD RECOMMENDS A VOTE FOR APPROVAL  OF
THE  MERGER AGREEMENT, FOR APPROVAL OF EACH  OF THE WPLH CHARTER AMENDMENTS, FOR
THE ELECTION OF  THE NOMINATED WPLH  DIRECTORS AND FOR  THE RATIFICATION OF  THE
APPOINTMENT OF THE INDEPENDENT AUDITORS.
 
    IES.   The IES Board believes that the terms of the Mergers are fair to, and
in the best interests of, IES and its shareholders. Accordingly, the IES  Board,
by  a unanimous vote of the directors present, has approved the Merger Agreement
and the  transactions  contemplated  thereby and  recommends  its  approval  and
adoption  by  IES's shareholders.  The IES  Board believes:  that the  IES Ratio
offers IES shareholders an attractive premium over the recent historical trading
prices of IES Common Stock; that IES shareholders will benefit by  participation
in  the combined economic  growth of the service  territories of Utilities, WP&L
and IPC,  and  from  the  inherent  increase  in  scale  economies,  the  market
diversification  and the resulting increased financial stability and strength of
the combined entity; that the Mergers will result in cost savings from decreased
electric  production  and  gas  supply  costs,  a  reduction  in  operating  and
maintenance  expense  and  other  factors  discussed  above;  that  the combined
enterprise can  more effectively  participate  in the  increasingly  competitive
market  for the generation of power; and that the Mergers and various provisions
of the  Merger Agreement  offer  IES shareholders,  ratepayers and  employees  a
unique  opportunity  to  realize the  benefits  created by  combining  the three
entities. The IES Board believes that  these factors offer a potential  increase
in earnings in excess of those that could be achieved by IES alone, and that the
Mergers will result in the creation of a larger, financially stronger company.
 
    In  reaching its conclusions, the IES  Board considered (i) the original and
the adjusted IES Ratio and the fact that such ratios represent approximately  an
11%  premium and an 11.34% premium, respectively,  over the closing price of IES
Common Stock on the NYSE on November  10, 1995 (the last full trading day  prior
to the public announcement of the Mergers) and premiums of approximately 14% and
14.43%,  respectively, over the closing price of IES Common Stock on the NYSE on
October 10, 1995 (the trading day that is 30 days prior to the date on which the
Mergers were  publicly announced);  (ii) the  financial performance,  condition,
business  operations and prospects of  each of IES, WPLH and  IPC and that, on a
combined basis, the companies will  likely have greater financial stability  and
strength due to
 
                                       49
<PAGE>
participation  in  the  combined economic  climate  and  growth of  each  of the
Utilities, WP&L  and IPC  service territories,  the inherent  increase in  scale
economies, the market diversification resulting from the combination of customer
bases and the impact of the potential operating efficiencies and other synergies
which are expected to reduce operational and maintenance expenses, as more fully
discussed  above;  (iii)  current  industry,  economic,  market  and  regulatory
conditions which encourage consolidation to  reduce risk and create new  avenues
for  earnings  growth (as  discussed  under "The  Mergers  -- Background  of the
Mergers" above); (iv)  IES's prospects  for earnings  and dividend  growth on  a
stand-alone  basis  in light  of IES's  size  relative to  many of  the electric
utility companies abutting Utilities' service territory (IES ranks ninth out  of
20 such companies based on aggregate market capitalization); (v) the recent wave
of  merger  activity  involving  electric  utility  companies  in  markets  near
Utilities' service  territory and  IES's  ability to  remain competitive  on  an
independent  basis over the  long-term; (vi) the  anticipated positive effect of
the  Mergers  on   IES's  shareholders  and   Utilities'  customers,   including
maintaining  competitiveness, integrating corporate and administrative functions
and reducing operating  costs (all  as more  fully described  above); (vii)  the
terms  of  the Merger  Agreement, the  Stock  Option Agreements,  the Employment
Agreements and other documents  executed and to be  executed in connection  with
the  Mergers which provide for the adjustment of  the IES Ratio in the event the
McLeod Contingency is satisfied (which has occurred), reciprocal representations
and warranties, conditions to  closing and rights  to termination, and  balanced
rights  and obligations; (viii) the management  succession plan specified in the
Merger  Agreement  and  the  Employment   Agreements  of  Messrs.  Liu,   Davis,
Stoppelmoor  and  Chase  (as  described  under  "--  Employment  Agreements" and
"Interstate Energy Following  the Mergers --  Management of Interstate  Energy")
which  provides a prudent plan for managing the integration of and transition in
management; (ix) the impact of regulation  under various state and federal  laws
(as  described under "Regulatory  Matters" and "--  Background of the Mergers");
(x) that the Mergers are expected  to be treated as tax-free reorganizations  to
shareholders  and  to be  accounted  for as  a  pooling-of-interests transaction
(which avoids the reduction in earnings which would result from the creation and
amortization of goodwill  under purchase  accounting); and (xi)  the opinion  of
Morgan Stanley, described below, that the IES Ratio, taking into account the IPC
Ratio,  is fair  from a  financial point of  view to  the holders  of IES Common
Stock. The  IES  Board  recognizes  that  (i)  giving  effect  to  the  Mergers,
equivalent  IES earnings per share will be  slightly lower than IES earnings per
share for the  12-months ended  September 30,  1995, (ii)  annual dividends  per
share  of Interstate  Energy Common  Stock are expected  to be  lower than those
which have been paid on IES Common Stock (see "Selected Historical and Pro Forma
Data"),  and  (iii)  recent  operating  revenues,  operating  income  and  other
financial  factors are  slightly higher for  IES than WPLH;  and, although these
factors are not immaterial, the IES Board believes the factors discussed in  the
preceding  sentences, together with those reasons discussed above and the advice
or assistance of  its financial  advisors and consultants  as described  herein,
substantially  outweigh any  negatives and  the terms of  the Mergers  are, as a
whole, in the best  interests of IES and  its shareholders. In determining  that
the Mergers are fair to and in the best interests of shareholders, the IES Board
considered  the above factors as a whole and did not assign specific or relative
weights to any one factor or group of factors.
 
    THE IES BOARD  HAS APPROVED THE  MERGER AGREEMENT BY  UNANIMOUS VOTE OF  THE
DIRECTORS  THEN PRESENT AND BELIEVES THAT THE  TERMS OF THE MERGERS ARE FAIR TO,
AND IN THE BEST INTERESTS OF,  IES'S SHAREHOLDERS, AND SUPPORTS THE ELECTION  OF
THE NOMINATED IES DIRECTORS. THE IES BOARD RECOMMENDS A VOTE FOR APPROVAL OF THE
MERGER AGREEMENT AND FOR THE ELECTION OF THE NOMINATED IES DIRECTORS.
 
    IPC.   The IPC Board believes that the terms of the Mergers are fair to, and
in the best interests of, IPC and its stockholders. Accordingly, the IPC  Board,
by  a unanimous  vote, has approved  the Merger Agreement  (and the transactions
contemplated  thereby)  and  recommends  its  approval  and  adoption  by  IPC's
stockholders.  The IPC Board further believes  that the IPC Charter Amendment is
an important  precondition  to  the  IPC Merger  in  order  to  secure  tax-free
reorganization  status for the IPC Merger or  the IPC Direct Merger, as the case
may be, under the  Code. Accordingly, the  IPC Board, by  a unanimous vote,  has
adopted   a   resolution   setting   forth  the   IPC   Charter   Amendment  and
 
                                       50
<PAGE>
declaring its advisability, and recommends approval of the IPC Charter Amendment
by IPC's stockholders. The IPC Board believes: that the IPC Ratio offers to  IPC
stockholders  an attractive premium over the recent historical trading prices of
IPC Common Stock;  that IPC stockholders  will benefit by  participation in  the
combined  economic growth of the service territories of IPC, WP&L and Utilities,
and from the anticipated increase in scale economies, the market diversification
and the resulting  increased financial  stability and strength  of the  combined
entity;  that the  Mergers will result  in cost savings  from decreased electric
production and  gas  supply costs,  a  reduction in  operating  and  maintenance
expense and other factors discussed above; that the combined enterprise can more
effectively   participate  in  the  increasingly   competitive  market  for  the
generation of power; and that the  Mergers and various provisions of the  Merger
Agreement  offer IPC stockholders, ratepayers and employees a unique opportunity
to realize the benefits created by  combining the three entities. The IPC  Board
believes  that these factors offer a potential increase in earnings in excess of
those that  could  be  achieved  by  IPC alone,  and  the  potential  for  IPC's
stockholders  to participate in  the creation of  a larger, financially stronger
company.
 
    In reaching its conclusions, the IPC Board considered (i) the IPC Ratio  and
the  fact that it represents  a premium of approximately  15.2% over the closing
price of IPC's  Common Stock on  the NYSE on  November 10, 1995  (the last  full
trading  day prior to the  public announcement of the  Mergers) and a premium of
approximately 22.4% over the closing price of IPC's Common Stock on October  10,
1995  (the trading day  that is 30 days  prior to the date  on which the Mergers
were publicly announced);  (ii) the financial  performance, condition,  business
operations  and prospects of each  of WPLH, IES and IPC  and that, on a combined
basis, the companies will likely  have greater financial stability and  strength
due  to participation in the combined economic climate and growth of each of the
WP&L, Utilities  and IPC  service territories,  the inherent  increase in  scale
economies, the market diversification resulting from the combination of customer
bases and the impact of the potential operating efficiencies and other synergies
that  are expected to reduce operational and maintenance expenses, as more fully
discussed  above;  (iii)  current  industry,  economic,  market  and  regulatory
conditions  that encourage consolidation  to reduce risk  and create new avenues
for earnings  growth (as  discussed  under "The  Mergers  -- Background  of  the
Mergers"  above); (iv)  IPC's prospects  for earnings  and dividend  growth on a
stand-alone basis  in light  of IPC's  size  relative to  many of  the  electric
utility  companies abutting IPC's  service territory (each of  which is at least
three times larger than IPC when measured  by any of a number of criteria);  (v)
the  recent  wave of  merger activity  involving  electric utility  companies in
markets near IPC's service territory and IPC's ability to remain competitive  on
an  independent basis over the long-term (vi) the anticipated positive effect of
the Mergers on IPC's stockholders and customers (as disclosed in more detail  in
the  preceding paragraph);  (vii) the terms  of the Merger  Agreement, the Stock
Option Agreements, the Employment Agreements and other documents executed and to
be executed  in  connection  with  the  Mergers  which  provide  for  reciprocal
representations and warranties, conditions to closing and rights to termination,
balanced  rights and obligations  and certain protections  for employees of IPC;
(viii) the management succession plan specified in the Merger Agreement and  the
Employment Agreements of Messrs. Liu, Davis, Stoppelmoor and Chase (as described
under "-- Employment Agreements" and "Interstate Energy Following the Mergers --
Management  of Interstate Energy") that provides a prudent plan for managing the
integration of and transition in management; (ix) the impact of regulation under
various state and federal laws (as described under "Regulatory Matters" and  "--
Background  of the Mergers"); (x)  that, subject to approval  of the IPC Charter
Amendment by the IPC stockholders at  the IPC Meeting, the Mergers are  expected
to  be treated as  tax-free reorganizations to stockholders  and to be accounted
for as  a  pooling-of-interests  transaction  (which  avoids  the  reduction  in
earnings  that would result from the creation and amortization of goodwill under
purchase accounting); and (xi) the opinion of Salomon Brothers, described below,
that the IPC Ratio is fair to the  holders of IPC Common Stock from a  financial
point  of view.  In determining  that the Mergers  are fair  to and  in the best
interests of its stockholders, the IPC  Board considered the above factors as  a
whole and did not assign specific or relative weights to any one factor or group
of factors.
 
                                       51
<PAGE>
    The   IPC  Board  did,  however,  consider  certain  countervailing  factors
associated with the Mergers. The first  factor related to the ownership by  WP&L
of  the Kewaunee Nuclear  Power facility and  the ownership by  Utilities of the
Duane Arnold Energy Center, both of which are nuclear power plants. IPC does not
own any interests  in nuclear  generating facilities. The  IPC Board  considered
generally  the ownership and operation of  nuclear generating facilities and the
potential generic  risks and  costs  associated therewith,  including  premature
permanent  plant shutdown, temporary plant shutdown, uneconomic plant operation,
consequences  of  a  nuclear  accident,  fuel  storage  and  fuel  disposal  and
decommissioning costs. The IPC Board also considered factors specific to each of
the Kewaunee and Duane Arnold facilities.
 
    With  respect to IES, the IPC Board considered the fact that Utilities was a
70% owner  of the  Duane Arnold  facility  and that  the Duane  Arnold  facility
provided  Utilities with approximately 18% of  its generating capability and 25%
of its energy requirements. Available estimates suggested that the Duane  Arnold
facility  faced a  decommissioning liability  of approximately  $361 million (in
1993 dollars) of which  Utilities is responsible for  70% or approximately  $253
million, with approximately $34 million (at the end of 1994) thereof accumulated
in  an external trust  fund and approximately  $21 million (at  the end of 1994)
thereof  accumulated  in  an  internal  reserve.  In  addition,  the  IPC  Board
considered  that the adequacy of the  Duane Arnold facility decommissioning plan
funding depended in part  on Utilities' success in  obtaining approval from  the
IUB  for a  significant increase in  its annual  decommissioning fund allocation
beginning in 1996. These  factors caused the IPC  Board to consider whether  the
Duane  Arnold facility was  likely to present  a material financial  risk in the
form of stranded investment  as the generation segment  of the electric  utility
industry moved toward deregulation and open competition.
 
    The  IPC  Board believed  that the  potential negative  impact of  the Duane
Arnold facility  was offset  by  various other  factors.  First, the  IPC  Board
believes,  based on ongoing proceedings at  FERC, that federal policymakers will
ultimately allow  for the  recovery of  stranded investment  in the  event  that
policies are implemented which bring about greater competition in the generation
sector  of the electric utility industry.  Second, all available information led
to the  conclusion  that the  Duane  Arnold  facility was  a  well-operated  and
well-managed  nuclear facility  whose costs  were generally  more favorable than
those of  most nuclear  plants in  North America.  Third, historical  regulatory
experiences   in  Iowa  presented  no   evidence  that  unreasonable  regulatory
ratemaking policies would likely be implemented with respect to the Duane Arnold
facility.
 
    With respect to  the Kewaunee facility,  the IPC Board  considered the  fact
that  WP&L  was a  41%  owner of  the Kewaunee  facility  and that  the Kewaunee
facility provided WP&L with approximately  16% of its generating capability  and
14%  of its energy requirements. The IPC  Board further considered the fact that
the  Kewaunee  facility  is  experiencing  certain  steam  generation  equipment
degradation  that  potentially  threatens the  economic  viability  of continued
operation of  the Kewaunee  facility.  These factors  caused  the IPC  Board  to
consider  whether  the  Kewaunee  facility  was  likely  to  present  a material
financial risk in terms of its future economic viability.
 
    The IPC Board believed  that the potential negative  impact of the  Kewaunee
facility  was  offset  by  various factors.  First,  the  Kewaunee  facility has
historically been one of the top  performing plants within the nuclear  industry
and  has recently received the highest  possible performance ratings assigned by
applicable regulatory agencies. Second, there exist viable economic alternatives
to the steam generator equipment degradation noted above, and WPLH's  management
has  indicated its belief  that the risks of  these alternatives are manageable.
Third, the IPC Board  believes that the plans  for decommissioning the  Kewaunee
facility at the end of its useful life are adequate.
 
    Although  the IPC  Board considered the  foregoing factors  in approving the
Mergers, the IPC Board concluded that  the potential unfavorable aspects of  the
Mergers  were outweighed by  the positive impacts and  potential benefits of the
Mergers described above.
 
    THE IPC BOARD  HAS UNANIMOUSLY  APPROVED THE MERGER  AGREEMENT AND  BELIEVES
THAT  THE TERMS OF THE MERGERS ARE FAIR  TO, AND IN THE BEST INTERESTS OF, IPC'S
STOCKHOLDERS,  HAS   UNANIMOUSLY  ADOPTED   A  RESOLUTION   SETTING  FORTH   THE
 
                                       52
<PAGE>
IPC  CHARTER AMENDMENT AND DECLARING ITS ADVISABILITY, AND SUPPORTS THE ELECTION
OF THE NOMINATED IPC DIRECTORS. THE IPC BOARD RECOMMENDS A VOTE FOR APPROVAL  OF
THE  MERGER AGREEMENT, FOR  APPROVAL OF THE  IPC CHARTER AMENDMENT,  AND FOR THE
ELECTION OF THE NOMINATED IPC DIRECTORS.
 
OPINIONS OF FINANCIAL ADVISORS
 
    WPLH'S FINANCIAL  ADVISOR.   During the  course of  discussions regarding  a
possible  transaction,  Merrill Lynch  attended meetings  of  the WPLH  Board as
described in  "The Mergers  -- Background  of the  Mergers." At  such  meetings,
Merrill  Lynch reviewed financial  information concerning WPLH,  IES and IPC and
provided preliminary  valuations  of  IES and  IPC.  The  financial  information
reviewed by Merrill Lynch was the same financial information used in arriving at
the  Merrill Lynch Opinion (as updated through  the relevant date), all of which
information is  described  below.  The results  of  the  preliminary  valuations
presented  by Merrill Lynch at such WPLH  Board meetings are consistent with the
results utilized by Merrill Lynch to arrive at the Merrill Lynch Opinion,  which
results are described below.
 
    On  November 10,  1995, Merrill Lynch  delivered its written  opinion to the
WPLH Board to the effect that, as  of such date, and based upon the  assumptions
made,  matters considered and limits of review as set forth in such opinion, the
Ratios (without adjustment of the IES  Ratio to reflect the satisfaction of  the
McLeod  Contingency) are fair to WPLH from a  financial point of view. On May 7,
1996, at a meeting of the WPLH Board, Merrill Lynch discussed and reviewed  with
the  WPLH Board the proposed contingent adjustment  to the IES Ratio relating to
the McLeod Contingency and orally confirmed that Merrill Lynch would be prepared
to render an opinion dated the date of this Joint Proxy Statement/Prospectus  to
the  effect that, as  of such date,  and based on  the assumptions made, matters
considered and  limits  of review  as  set forth  in  such opinion,  the  Ratios
(including  the IES Ratio  as adjusted if the  McLeod Contingency was satisfied)
are fair to WPLH from a financial point of view. In a written opinion dated  the
date  of this Joint Proxy Statement/Prospectus,  Merrill Lynch confirmed (i) its
November 10, 1995 opinion as it relates  to the Ratios (including the IES  Ratio
as  adjusted to reflect the satisfaction of the McLeod Contingency) and (ii) the
appropriateness of its reliance on the analyses used to render the November  10,
1995  opinion by performing procedures to  update such analyses and by reviewing
the assumptions on  which such analyses  were based and  the factors  considered
therewith.  Merrill Lynch  performed and updated  the same  analyses utilized in
rendering the  November  10, 1995  opinion,  including reviewing  the  financial
information  on which such analyses were  based and the recent financial results
of  WPLH,  IES  and  IPC,  and  the  results  of  such  updated  analyses   were
substantially  similar to the  prior results. References  herein to the "Merrill
Lynch Opinion" refer to the written opinion of Merrill Lynch dated November  10,
1995.
 
    A  COPY OF  THE MERRILL  LYNCH OPINION  DATED THE  DATE OF  THIS JOINT PROXY
STATEMENT/PROSPECTUS, WHICH SETS FORTH THE ASSUMPTIONS MADE, MATTERS  CONSIDERED
AND  CERTAIN LIMITATIONS ON THE SCOPE OF  REVIEW UNDERTAKEN BY MERRILL LYNCH, IS
ATTACHED AS ANNEX L TO  THIS JOINT PROXY STATEMENT/PROSPECTUS. WPLH  SHAREOWNERS
ARE  URGED TO READ SUCH OPINION IN  ITS ENTIRETY. THE MERRILL LYNCH OPINIONS ARE
DIRECTED ONLY TO THE FAIRNESS OF THE  RATIOS FROM A FINANCIAL POINT OF VIEW  AND
DO  NOT  CONSTITUTE A  RECOMMENDATION  TO ANY  WPLH  SHAREOWNER AS  TO  HOW SUCH
SHAREOWNER SHOULD VOTE  AT THE WPLH  MEETING. THE SUMMARY  OF THE MERRILL  LYNCH
OPINION  SET FORTH IN THIS JOINT  PROXY STATEMENT/PROSPECTUS IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO THE FULL TEXT OF THE MERRILL LYNCH OPINION ATTACHED  AS
ANNEX  L HERETO. THE  MERRILL LYNCH OPINION  DATED THE DATE  OF THIS JOINT PROXY
STATEMENT/PROSPECTUS IS SUBSTANTIALLY SIMILAR TO THE MERRILL LYNCH OPINION DATED
NOVEMBER 10, 1995.
 
    In arriving at the Merrill Lynch  Opinion, Merrill Lynch among other  things
(i)  reviewed WPLH's,  IES's, and IPC's  Annual Reports, Forms  10-K and related
financial information for the  three fiscal years ended  December 31, 1994,  and
Forms 10-Q and related unaudited financial information for the quarterly periods
ended  June 30, 1995; (ii)  reviewed certain other filings  with the SEC made by
WPLH, IES,  and IPC,  including proxy  statements, Forms  8-K, and  registration
statements,  during the  last three  years; (iii)  reviewed certain information,
including financial forecasts,  relating to the  business, earnings,  dividends,
cash  flow, assets  and prospects  of WPLH, IES,  and IPC,  furnished to Merrill
Lynch by  WPLH, IES,  and  IPC, respectively;  (iv) conducted  discussions  with
members of
 
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<PAGE>
senior  management of WPLH, IES and  IPC concerning their respective businesses,
regulatory  environments,  prospects  and  strategic  objectives  and   possible
operating,  administrative and capital synergies which might be realized for the
combined companies following  the Mergers;  (v) reviewed  the historical  market
prices  and trading activity  for WPLH Common  Stock, IES Common  Stock, and IPC
Common Stock; (vi) compared the results of operations of WPLH, IES and IPC  with
those  of certain companies deemed by Merrill  Lynch to be reasonably similar to
WPLH, IES and IPC, respectively; (vii) compared the proposed financial terms  of
the  Mergers with the financial terms  of certain other mergers and acquisitions
which Merrill  Lynch  deemed  to  be  relevant;  (viii)  analyzed  the  relative
valuation  of WPLH Common  Stock, IES Common  Stock, and IPC  Common Stock using
various valuation methodologies  which Merrill Lynch  deemed to be  appropriate;
(ix)  considered the  pro forma effect  of the  Mergers, in terms  of net income
available to common  stockholders, dividends  per common share,  book value  per
common  share and capitalization,  on WPLH Common Stock;  (x) reviewed drafts of
the Merger Agreement and  the Stock Option Agreements,  dated November 10,  1995
and  November  6, 1995,  respectively; and  (xi)  reviewed such  other financial
studies and analyses  and made  such other inquiry  and took  into account  such
other  matters deemed necessary or appropriate  by Merrill Lynch for purposes of
the Merrill Lynch Opinion.
 
    In preparing  the  Merrill  Lynch  opinions, Merrill  Lynch  relied  on  the
accuracy  and  completeness  of  all  information  supplied  or  otherwise  made
available to it  by WPLH, IES  and IPC,  and did not  independently verify  such
information  or any underlying  assumptions. Merrill Lynch  did not undertake an
independent appraisal  or  physical  inspection of  the  assets  or  liabilities
(contingent  or otherwise) of WPLH, IES or  IPC. Merrill Lynch also assumed that
the financial forecasts and projected synergies furnished to it by WPLH, IES and
IPC were reasonably prepared in accordance with accepted industry practices  and
reflected  the best currently available estimates and judgments of WPLH's, IES's
and IPC's management as  to the expected future  financial performance of  WPLH,
IES  and IPC, respectively, and as to  the expected future projected outcomes of
various legal, regulatory  and other contingencies.  Merrill Lynch also  assumed
that  the  Mergers  will be  free  of Federal  tax  to  WPLH, IES,  IPC  and the
respective holders of WPLH Common Stock, IES Common Stock and IPC Common  Stock,
and  further assumed  that the  Mergers will  be accounted  for as  a pooling of
interests. Merrill Lynch's  opinions are  based upon  general economic,  market,
monetary  and other conditions as  they existed and could  be evaluated, and the
information made available to it, as  of the respective dates of such  opinions.
The  Merrill  Lynch opinions  do  not constitute  a  recommendation to  any WPLH
shareowner as to how such shareowner should vote at the WPLH Meeting.
 
    The matters considered  by Merrill Lynch  in arriving at  the Merrill  Lynch
opinions   are  based   on  numerous  macroeconomic,   operating  and  financial
assumptions with respect to industry performance, general business and  economic
conditions,  many of  which are  beyond the  control of  WPLH, IES  and IPC, and
involve the  application of  complex methodologies  and educated  judgment.  Any
estimates  incorporated  in  the analyses  performed  by Merrill  Lynch  are not
necessarily indicative of actual past or future results or values, which may  be
significantly  more or less  favorable than such  estimates. Estimated values do
not purport to be appraisals and do not necessarily reflect the prices at  which
businesses or companies may be sold in the future. The Merrill Lynch opinions do
not  present a discussion of  the relative merits of  the Mergers as compared to
any other business plan or opportunity that  might be presented to WPLH, or  the
effect of any other arrangement in which WPLH might engage.
 
    The  following is  a summary of  certain financial  and comparative analyses
performed by Merrill Lynch in arriving at its November 10, 1995 opinion. Merrill
Lynch derived implied exchange  ratios for WPLH Common  Stock, IES Common  Stock
and IPC Common Stock based upon what these analyses, when considered in light of
the  judgment and  experience of Merrill  Lynch, suggested  about their relative
values. The Merrill Lynch Opinion is based upon Merrill Lynch's consideration of
the collective results  of all such  analyses, together with  the other  factors
referred  to in its opinion letter. In  the Mergers, each issued and outstanding
share of IES Common Stock will be converted into the right to receive 0.98 of  a
share  of Interstate Energy  Common Stock (subsequently  adjusted to 1.01 shares
upon satisfaction of the  McLeod Contingency), and  each issued and  outstanding
share of IPC Common Stock will be ultimately converted into the right to receive
1.11 shares of Interstate Energy Common Stock. In concluding that the Ratios are
fair    to   WPLH    and   in   its    discussions   with    the   WPLH   Board,
 
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<PAGE>
Merrill  Lynch compared  the IES Ratio  and IPC  Ratio to each  range of implied
exchange ratios set forth below, which were derived from the analyses  performed
by  it, and  noted as generally  supporting its opinion  that 0.98 (subsequently
adjusted to 1.01  upon satisfaction  of the  McLeod Contingency)  and 1.11  were
consistent  with the  ranges of  such implied  exchange ratios  for each  of IES
Common Stock to  WPLH Common Stock  and IPC  Common Stock to  WPLH Common  Stock
derived  from comparable publicly traded company analysis (0.84 to 1.07 and 0.82
to 1.18, respectively), contribution  analysis (0.91 to 1.16  and 0.82 to  1.09,
respectively),  dividend  discount  analysis (0.82  to  1.32 and  0.78  to 1.24,
respectively), discounted cash  flow analysis (0.75  to 1.38 and  0.65 to  1.28,
respectively),  and comparable  acquisition transactions analysis  (0.75 to 1.36
and 0.81 to 1.50, respectively).
 
    TRADING RATIO ANALYSIS.  Merrill Lynch  reviewed the performance of the  per
share  market price of WPLH Common Stock,  IES Common Stock and IPC Common Stock
over the five year period ended November 7, 1995. Merrill Lynch also  calculated
the  ratio of the  per share market  price of each  of IES Common  Stock and IPC
Common Stock to the per share market price of WPLH Common Stock from November 7,
1990 to November 7, 1995, November 7, 1992 to November 7, 1995, and November  7,
1994  to November 7, 1995. This analysis  showed that over the five year period,
the per share market price of IES Common Stock and IPC Common Stock compared  to
the  price of WPLH  Common Stock, traded  at average ratios  of 0.922 and 0.939,
respectively. Over the three year period this analysis showed that the per share
market price of IES Common Stock and  IPC Common Stock compared to the price  of
WPLH  Common Stock, traded  at average ratios of  0.903 and 0.871, respectively.
Over the one year period this analysis showed that the per share market price of
IES Common Stock  and IPC  Common Stock  compared to  the price  of WPLH  Common
Stock,  traded at average ratios of 0.864  and 0.848, respectively. Based on the
November 7, 1995 closing prices, the trading ratios of the IES Common Stock  and
IPC  Common Stock  were 0.886 and  0.980, respectively, compared  to the closing
price of WPLH Common Stock on that day.
 
    COMPARABLE PUBLICLY  TRADED  COMPANY  ANALYSIS.   Using  publicly  available
information,  Merrill Lynch compared certain financial and operating information
and ratios  (described below)  for WPLH,  IES and  IPC, respectively,  with  the
corresponding financial and operating information and ratios for separate groups
of  publicly  traded  companies  that  Merrill  Lynch  deemed  to  be reasonably
comparable to WPLH,  IES and IPC,  respectively. The companies  included in  the
WPLH  comparable company analyses were: Delmarva Power and Light Company, Kansas
City Power and Light Company,  and WPS Resources Corporation (collectively,  the
"ML  WPLH Comparables").  The companies included  in the  IES comparable company
analyses were: MidAmerican Energy  Company and Minnesota  Power & Light  Company
(collectively,  the "ML  IES Comparables").  The companies  included in  the IPC
comparable company analyses  were: Central  Hudson Gas  & Electric  Corporation,
CILCORP, Inc., Madison Gas & Electric Company, Orange & Rockland Utilities, Inc.
and  Southern  Indiana  Gas  &  Electric  Company  (collectively,  the  "ML  IPC
Comparables"). Merrill Lynch selected the companies in the ML WPLH  Comparables,
ML  IES Comparables and  ML IPC Comparables, respectively,  from the universe of
possible comparable utility companies based upon Merrill Lynch's views as to the
comparability of financial and operating  characteristics of these companies  to
WPLH, IES and IPC, respectively.
 
    In  order to determine an implied exchange ratio range based upon comparable
publicly traded company  analysis, Merrill  Lynch compared the  market value  of
WPLH  Common Stock, IES Common Stock, and IPC  Common Stock as a multiple of (a)
estimated 1995 earnings per  share ("EPS"), which  estimates were obtained  from
First  Call (the "1995 EPS Ratio"), (b) estimated 1996 EPS, which estimates were
obtained from First Call (the "1996 EPS Ratio"), (c) book value of common equity
as of June  30, 1995, the  most recently available  fiscal quarter (the  "Common
Equity  Ratio"), and (d) indicated dividend yield (the "Dividend Ratio"), to the
corresponding ratios for each of the ML WPLH Comparables, ML IES Comparables and
ML IPC Comparables. First Call is a data service which monitors and publishes  a
compilation  of  earnings estimates  produced by  selected research  analysts on
companies of interest to investors. The  results of the foregoing were: (i)  the
1995  EPS Ratio resulted  in a range  of implied exchange  ratios for IES Common
Stock to WPLH Common Stock and IPC Common Stock to WPLH Common Stock of 0.87  to
1.02 and 0.84 to 1.11, respectively, (ii) the
 
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<PAGE>
1996  EPS Ratio resulted in  a range of implied exchange  ratios of 0.89 to 1.04
and 0.82 to  1.05, respectively,  (iii) the Common  Equity Ratio  resulted in  a
range of implied exchange ratios of 0.86 to 1.07 and 0.86 to 1.18, respectively,
and  (iv) the Dividend Ratio  resulted in a range  of implied exchange ratios of
0.84 to 1.01 and 0.92 to 1.16, respectively.
 
    Utilizing  comparable  publicly  traded  company  analysis,  Merrill   Lynch
calculated  implied exchange  ratio ranges for  IES Common Stock  to WPLH Common
Stock and IPC  Common Stock to  WPLH Common Stock  of 0.84 to  1.07 and 0.82  to
1.18, respectively.
 
    CONTRIBUTION  ANALYSIS.   In order  to determine  an implied  exchange ratio
range  based   upon  contribution   analysis,  Merrill   Lynch  calculated   the
contribution of each of WPLH, IES and IPC to the pro forma combined company with
respect to (i) earnings per common share (ii) common equity per common share and
(iii)  dividends  per  common  share,  for  the  years  1993  through  1994 (the
"Historical Period") and, using certain  projections provided by the  respective
managements  of  WPLH,  IES  and  IPC, for  the  years  1995  through  1999 (the
"Projected Period"). The analysis of earnings  per common share yielded a  range
of  implied exchange ratios  for IES Common  Stock to WPLH  Common Stock and IPC
Common Stock to WPLH Common Stock of 1.10 to 1.16 and 0.82 to 0.90, respectively
during the Historical  Period and 0.91  to 1.09 and  0.91 to 1.08,  respectively
during  the Projected  Period. The  analysis of  common equity  per common share
yielded a range of  implied exchange ratios  of 1.05 to 1.06  and 1.04 to  1.04,
respectively  during the Historical  Period and 1.06  to 1.09 and  1.01 to 1.03,
respectively during the Projected Period.  The analysis of dividends per  common
share  yielded a range  of implied exchange ratios  of 1.09 to  1.11 and 1.08 to
1.09, respectively during  the Historical Period  and 1.06 to  1.08 and 1.03  to
1.07, respectively during the Projected Period. In arriving at the Merrill Lynch
Opinion,  Merrill Lynch considered, as one of  the factors in its analysis, that
the Ratios are outside of certain of the implied exchange ratios.
 
    DIVIDEND DISCOUNT ANALYSIS.  In order to determine an implied exchange ratio
range based upon dividend discount analysis, Merrill Lynch calculated ranges  of
value  for WPLH Common Stock,  IES Common Stock and  IPC Common Stock based upon
the sum of the present value, assuming equity discount rates ranging from  8.75%
to  10.25%, of (a) each  of WPLH's, IES's and  IPC's projected dividends for the
years 1996 through 1999 using the same management projections, and (b) the  1999
value  of WPLH,  IES and IPC,  respectively, assuming  perpetual dividend growth
rates ranging from 1.50% to 2.00% for WPLH, 1.25% to 1.75% for IES and 1.00%  to
1.50% for IPC.
 
    Utilizing  dividend  discount  analysis,  Merrill  Lynch  calculated implied
exchange ratio ranges for IES Common Stock  to WPLH Common Stock and IPC  Common
Stock to WPLH Common Stock of 0.82 to 1.32 and 0.78 to 1.24, respectively.
 
    DISCOUNTED  CASH FLOW ANALYSIS.   In order to  determine an implied exchange
ratio range  based upon  discounted cash  flow ("DCF")  analysis, Merrill  Lynch
performed unlevered DCF analyses for the primary businesses of WPLH, IES and IPC
using  the same management projections, and  calculated ranges of value for WPLH
Common Stock, IES Common Stock and IPC Common Stock.
 
    Merrill Lynch  performed  separate discounted  cash  flow analyses  for  the
following  subsidiaries of  WPLH: WP&L, Heartland  Environmental Holding Company
("EHC"), and Heartland Properties, Inc. ("HPI").  WP&L's DCF was based upon  the
discount to present value, assuming discount rates ranging from 7.5% to 9.5%, of
(i)  its projected unlevered free cash flow for the years 1996 through 1999, and
(ii) its 1999  value based upon  a range of  multiples from 12.0x  to 13.0x  its
projected  1999 net income, and 1.6x to 1.8x its projected 1999 book value, plus
in each case assumed debt  and preferred stock at  year-end 1999. EHC's DCF  was
based  upon the discount to present  value, assuming discount rates ranging from
10.0% to 12.0%, of (i) its projected unlevered free cash flow for the years 1996
through 1999, and (ii) its 1999 value based upon a range of multiples from  7.0x
to  8.0x its projected  1999 earnings before interest  and taxes ("EBIT"). HPI's
DCF was  based upon  the  discount to  present  value, assuming  discount  rates
ranging  from  10.0%  to  14.0%,  of  its  projected  unlevered  free  cash flow
 
                                       56
<PAGE>
for the years 1996 through 1999.  In addition, Merrill Lynch calculated a  range
of  value for HPI  based upon its  book value. Based  on these analyses, Merrill
Lynch calculated a  range of  value for  WPLH Common  Stock of  $820 million  to
$1,111 million.
 
    Merrill  Lynch  performed separate  discounted  cash flow  analyses  for the
following  subsidiaries  of  IES:  Utilities,  Industrial  Energy   Applications
("IEA"),  and Cedar Rapids and Iowa City Railway Company ("CRANDIC"). Utilities'
DCF was  based upon  the  discount to  present  value, assuming  discount  rates
ranging from 7.5% to 9.5%, of (i) its projected unlevered free cash flow for the
years 1996 through 1999, and (ii) its 1999 value based upon a range of multiples
from  12.0x  to  13.0x its  projected  1999 net  income,  and 1.6x  to  1.8x its
projected 1999 book  value, plus  in each case  assumed net  debt and  preferred
stock  at year-end 1999. IEA's DCF was based upon the discount to present value,
assuming discount  rates ranging  from  10.0% to  12.0%,  of (i)  its  projected
unlevered  free cash  flow for the  years 1996  through 1999, and  (ii) its 1999
value based upon  a range  of multiples  from 7.0x  to 9.0x  its projected  1999
earnings  before  interest,  taxes,  depreciation  and  amortization ("EBITDA").
CRANDIC's DCF was based  upon the discount to  present value, assuming  discount
rates  ranging from 11.0% to  13.0%, (i) its projected  unlevered free cash flow
for the years 1996 through 1999, and (ii)  its 1999 value based upon a range  of
multiples  from 6.0x  to 7.0x  its projected  1999 EBITDA.  In addition, Merrill
Lynch calculated  a  range of  value  for IES's  Whiting  Petroleum  Corporation
subsidiary  based upon a range of $3.50  to $5.00 per barrel of oil equivalents.
Based on  these analyses,  Merrill Lynch  calculated a  range of  value for  IES
Common Stock of $788 million to $1,075 million.
 
    IPC's  DCF was based  upon the discount to  present value, assuming discount
rates ranging from 7.5% to 9.5%, of  (i) its projected unlevered free cash  flow
for  the years 1996 through 1999, and (ii)  its 1999 value based upon a range of
multiples from 11.5x to 12.5x  its projected 1999 net  income, and 1.6x to  1.8x
its  projected 1999 book value, plus in each case assumed net debt and preferred
stock at year-end 1999. Based on this analysis, Merrill Lynch calculated a range
of value for IPC Common Stock of $223 million to $326 million.
 
    Utilizing DCF  analysis, Merrill  Lynch  calculated implied  exchange  ratio
ranges  for IES Common Stock  to WPLH Common Stock and  IPC Common Stock to WPLH
Common Stock were 0.75 to 1.38 and 0.65 to 1.28, respectively.
 
    COMPARABLE  MERGER  TRANSACTIONS   ANALYSIS.     Using  publicly   available
information,  Merrill Lynch reviewed eleven transactions announced between March
16, 1990  and September  25, 1995,  involving the  merger of  selected  electric
utility  companies (the "Comparable Merger Transactions"). The Comparable Merger
Transactions and  the  date  the  transaction was  announced  were  as  follows:
Baltimore  Gas and  Electric Company/Potomac  Electric Power  Company (September
1995), Public Service  Company of Colorado/Southwestern  Public Service  Company
(August   1995),  Union  Electric  Company/CIPSCO  Incorporated  (August  1995),
Northern States Power Company/Wisconsin  Energy Corporation (May 1995),  Midwest
Resources  Inc./Iowa-Illinois  Gas &  Electric  Company (July  1994), Washington
Water Power  Company/Sierra  Pacific Resources  (June  1994), Cincinnati  Gas  &
Electric  Company/PSI  Resources, Inc.  (August 1993),  Entergy Corporation/Gulf
States Utilities Company  (June 1992), IE  Industries, Inc./Iowa Southern,  Inc.
(February  1991), Kansas  Power &  Light Company/Kansas  Gas &  Electric Company
(October 1990), and Iowa Resources, Inc./Midwest Energy Company (March 1990).
 
    In order to determine  an implied exchange ratio  range based on  comparable
merger transactions analysis, Merrill Lynch (i) compared the offer value in each
of  the  Comparable  Merger Transactions  as  a  multiple of  the  then publicly
available (a) latest twelve months ("LTM") net income available to common  stock
(the  "Net Income Multiple"), and  (b) book value of  common equity for the most
recently available fiscal  quarter preceding such  transaction (the "Book  Value
Multiple")  and (ii)  compared the  transaction value  (defined to  be the offer
value plus the liquidation value of preferred stock plus the principal amount of
debt  less  cash  and  option  proceeds)  for  each  of  the  Comparable  Merger
Transactions  as a  multiple of  the then publicly  available (a)  LTM EBIT (the
"EBIT  Multiple"),  and  (b)  LTM   EBITDA  (the  "EBITDA  Multiple"),  to   the
corresponding multiples
 
                                       57
<PAGE>
for WPLH Common Stock, IES Common Stock and IPC Common Stock. The results of the
foregoing  were: (i)  the Net  Income Multiple  resulted in  a range  of implied
exchange ratios for IES Common Stock to  WPLH Common Stock and IPC Common  Stock
to  WPLH Common Stock of  0.85 to 1.22 and 0.83  to 1.20, respectively, (ii) the
Book Value Multiple resulted in  a range of implied  exchange ratios of 0.92  to
1.17 and 0.93 to 1.17, respectively, (iii) the EBIT Multiple resulted in a range
of  implied exchange ratios of 0.75 to  1.36 and 0.81 to 1.50, respectively, and
(iv) the EBITDA Multiple resulted in a range of implied exchange ratios of  0.87
to 1.35 and 0.84 to 1.32, respectively.
 
    Utilizing   the  comparable  merger  transactions  analysis,  Merrill  Lynch
calculated implied exchange  ratio ranges for  IES Common Stock  to WPLH  Common
Stock  and IPC Common  Stock to WPLH  Common Stock of  0.75 to 1.36  and 0.81 to
1.50, respectively.
 
    PRO FORMA ANALYSIS.  Merrill Lynch  also analyzed certain pro forma  effects
resulting from the Mergers, including the potential impact to earnings per share
of  WPLH Common Stock. Using  the projected earnings for  the years 1997 through
1999 provided by the respective managements of WPLH, IES and IPC, Merrill  Lynch
compared  the  projected  earnings per  share  of  WPLH on  a  stand-alone basis
assuming the  Mergers do  not occur,  to the  earnings per  share of  Interstate
Energy  Common Stock assuming the Ratios  of 0.98 (subsequently adjusted to 1.01
upon satisfaction  of  the  McLeod  Contingency)  and  1.11  for  IES  and  IPC,
respectively,  and certain estimated  synergies that WPLH  management expects to
achieve as a  result of  the Mergers. The  analysis indicated  that the  Mergers
would  be accretive to the projected earnings  per share of a WPLH shareowner in
amounts of 6.6% in 1997,  8.8% in 1998, and 8.3%  in 1999. In addition,  Merrill
Lynch  made  a  similar comparison  assuming  the Ratios  of  0.98 (subsequently
adjusted to 1.01 upon satisfaction of  the McLeod Contingency) and 1.11 for  IES
and  IPC, respectively,  no synergies, and  projected earnings  for IES adjusted
with the  guidance  of WPLH  management  to  give effect  to  more  conservative
assumptions.  The analysis indicated that the  Mergers would be accretive to the
projected earnings per share of a WPLH shareowner in the amount of 0.4% in 1997,
and dilutive to the projected earnings per share of a WPLH shareowner in amounts
of (2.4%) in 1998, and (3.0%) in 1999.
 
    On May 7, 1996, at a meeting of the WPLH Board, Merrill Lynch discussed  and
reviewed with the WPLH Board the proposed contingent adjustment to the IES Ratio
relating  to  the McLeod  Contingency.  Following is  a  summary of  all  of the
analyses that Merrill Lynch performed in connection with the McLeod Contingency.
Merrill Lynch calculated the potential contribution of the proceeds of  McLeod's
proposed  initial public  offering, based on  a range of  possible final pricing
terms for McLeod's proposed  initial public offering,  and compared the  overall
aggregate  percentage  share  ownership  of the  combined  company  assuming the
Mergers were consummated at the Ratios (assuming the IES Ratio was not  adjusted
to  1.01) and the IES Ratio as  adjusted if the McLeod Contingency was satisfied
as follows: (i) the holders of WPLH Common Stock would own 43.6% of the combined
company assuming the Mergers  were consummated at the  Ratios (assuming the  IES
Ratio  was  not adjusted  to 1.01)  compared  to 43.0%  of the  combined company
assuming the Mergers were consummated at the IES Ratio as adjusted if the McLeod
Contingency was satisfied, (ii) the holders of IES Common Stock would own  41.3%
of  the combined  company assuming  the Mergers  were consummated  at the Ratios
(assuming the IES  Ratio was  not adjusted  to 1.01)  compared to  42.1% of  the
combined  company  assuming the  Mergers were  consummated at  the IES  Ratio as
adjusted if the McLeod  Contingency was satisfied and  (iii) the holders of  IPC
Common  Stock would own 15.1% of the  combined company assuming the Mergers were
consummated at the  Ratios (assuming  the IES Ratio  was not  adjusted to  1.01)
compared  to 14.9% of the combined company assuming the Mergers were consummated
at the IES Ratio as adjusted if the McLeod Contingency was satisfied.
 
    The summary set forth above does not purport to be a complete description of
the analyses  performed  by Merrill  Lynch  in  arriving at  the  Merrill  Lynch
Opinion.  The  preparation  of  a  fairness opinion  is  a  complex  process not
necessarily susceptible to partial or  summary description. Although certain  of
the  implied exchange  ratios calculated as  described above are  outside of the
Ratios, Merrill Lynch believes that its  analyses must be considered as a  whole
and that selecting portions of its analyses and of the factors considered by it,
without considering all such factors and analyses, could
 
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create a misleading view of the process underlying its analyses set forth in the
Merrill  Lynch  Opinion. No  company  in the  ML  WPLH Comparables,  the  ML IES
Comparables or  the  ML IPC  Comparables  is identical  to  WPLH, IES,  or  IPC,
respectively, and none of the Comparable Merger Transactions is identical to the
Mergers.  Accordingly, an analysis  of comparable publicly  traded companies and
comparable acquisition  transactions is  not  mathematical; rather  it  involves
complex  considerations and  judgments concerning  differences in  financial and
operating characteristics of  the comparable  companies and  other factors  that
could  affect the public trading value of the comparable companies or company to
which they are being compared.
 
    The WPLH Board selected Merrill Lynch  to render a fairness opinion  because
Merrill  Lynch  is an  internationally recognized  investment banking  firm with
substantial experience in transactions similar to the Mergers and because it  is
familiar  with  WPLH and  its  business. Merrill  Lynch  has from  time  to time
rendered investment banking, financial advisory and other services to WPLH,  its
subsidiary  WP&L,  IES, its  subsidiary  Utilities, and  IPC,  for which  it has
received customary compensation.  As part  of its  investment banking  business,
Merrill  Lynch is continually  engaged in the valuation  of businesses and their
securities in connection with mergers and acquisitions.
 
    Pursuant to the terms of an  engagement letter dated June 29,1995, WPLH  has
agreed  to pay Merrill Lynch (i) a $100,000 retainer fee, payable as of the date
of the engagement letter, (ii) $200,000 payable upon the execution of the Merger
Agreement, (iii) $200,000 payable upon the delivery of the Merrill Lynch Opinion
and (iv) a transaction fee payable  only upon consummation of the Mergers  equal
to 0.40% of the product of the closing price of WPLH Common Stock on November 6,
1995,  which was $30.75, multiplied by the  sum of (a) 10,616,359, the number of
outstanding shares of  IPC Common  Stock as set  forth in  the Merger  Agreement
multiplied  by  the IPC  Ratio, and  (b) 29,639,029,  the number  of outstanding
shares of IES Common Stock  as set forth in  the Merger Agreement multiplied  by
the  IES Ratio (approximately $4,951,413), against which the amounts referred to
in clauses (i) - (iii) above will be credited. WPLH has also agreed to reimburse
Merrill  Lynch  for  its   reasonable  out-of-pocket  expenses,  including   all
reasonable fees and disbursements of its legal counsel, and to indemnify Merrill
Lynch and certain related persons against certain liabilities in connection with
its engagement, including certain liabilities under the federal securities laws.
 
    In  the  ordinary  course of  Merrill  Lynch's business,  Merrill  Lynch may
actively trade the securities of WPLH, IES  and IPC for its own account and  for
the  accounts of its customers and, accordingly, may  at any time hold a long or
short position in such securities.
 
    IES'S FINANCIAL ADVISOR.  On June  30, 1995, Morgan Stanley was retained  by
IES  to act  as its  financial advisor  in connection  with the  Mergers. Morgan
Stanley is  an  internationally  recognized  investment  banking  firm  and  was
selected  by  IES  based  on  Morgan  Stanley's  experience  and  expertise.  In
connection with Morgan Stanley's engagement,  IES requested that Morgan  Stanley
evaluate  the fairness of the IES Ratio, taking into account the IPC Ratio, from
a financial point of view  to the holders of IES  Common Stock. On November  10,
1995,  Morgan Stanley rendered  to the IES  Board an oral  opinion to the effect
that, as  of  such date,  and  based upon  the  procedures and  subject  to  the
assumptions  stated at the meeting, the IES Ratio (prior to consideration of the
McLeod Contingency),  taking  into  account  the IPC  Ratio,  was  fair  from  a
financial  point of view to the holders of  IES Common Stock. On April 29, 1996,
at a telephonic meeting of the IES Board of Directors, Morgan Stanley  discussed
and  reviewed with the IES  Board the proposed contingent  adjustment to the IES
Ratio  relating  to   the  McLeod   Contingency  and   orally  confirmed   that,
notwithstanding  the fact that Morgan Stanley  had not yet convened its internal
fairness opinion committee  to consider  such matters,  based on  the facts  and
circumstances existing at such time, Morgan Stanley anticipated that it would be
able  to render an opinion dated the date hereof, to the effect that, as of such
date, and based upon the procedures and subject to the assumptions stated at the
November 10, 1995 IES Board meeting and set forth in the fairness opinion  dated
the  date of this Joint Proxy Statement/Prospectus, which is attached as Annex M
to  this  Joint   Proxy  Statement/Prospectus,   the  IES   Ratio  (whether   or
 
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<PAGE>
not  the IES Ratio was adjusted if the McLeod Contingency was satisfied), taking
into account  the IPC  Ratio, is  fair from  a financial  point of  view to  the
holders  of IES Common Stock. In a written opinion dated the date hereof, Morgan
Stanley confirmed its November 10, 1995 oral opinion.
 
    THE FULL TEXT  OF MORGAN STANLEY'S  WRITTEN OPINION DATED  THE DATE  HEREOF,
WHICH SETS FORTH THE ASSUMPTIONS MADE, MATTERS CONSIDERED AND LIMITATIONS ON THE
REVIEW   UNDERTAKEN,   IS   ATTACHED   AS   ANNEX   M   TO   THIS   JOINT  PROXY
STATEMENT/PROSPECTUS AND IS  INCORPORATED HEREIN  BY REFERENCE.  HOLDERS OF  IES
COMMON  STOCK  ARE URGED  TO, AND  SHOULD,  READ THIS  OPINION CAREFULLY  IN ITS
ENTIRETY. MORGAN STANLEY'S OPINION ADDRESSES ONLY THE FAIRNESS OF THE IES  RATIO
(INCLUDING  THE IES RATIO AS ADJUSTED TO  REFLECT THE SATISFACTION OF THE MCLEOD
CONTINGENCY), TAKING INTO ACCOUNT THE IPC RATIO, FROM A FINANCIAL POINT OF  VIEW
TO  THE HOLDERS OF IES COMMON STOCK, AND IT DOES NOT ADDRESS ANY OTHER ASPECT OF
THE MERGERS NOR DOES IT CONSTITUTE A RECOMMENDATION TO ANY HOLDER OF IES  COMMON
STOCK AS TO HOW TO VOTE AT THE IES MEETING. THE SUMMARY OF THE OPINION OF MORGAN
STANLEY  SET FORTH IN THIS JOINT  PROXY STATEMENT/PROSPECTUS IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO THE FULL TEXT OF SUCH OPINION.
 
    In arriving at this opinion,  Morgan Stanley: (i) analyzed certain  publicly
available  financial statements and other information of IES, WPLH and IPC; (ii)
analyzed certain internal  financial statements and  other historical  financial
and  operating data  concerning IES, WPLH  and IPC prepared  by their respective
managements; (iii) analyzed certain financial  projections of IES, WPLH and  IPC
prepared  by their respective managements; (iv) reviewed certain public research
reports concerning  IES,  WPLH  and  IPC prepared  by  certain  equity  research
analysts  and discussed these research  reports, including financial projections
contained therein, with senior  executives of IES,  WPLH and IPC,  respectively;
(v)  discussed the past  and current operations and  financial condition and the
prospects of IES,  WPLH and IPC  with senior  executives of IES,  WPLH and  IPC,
respectively;  (vi) reviewed the reported prices and trading activity of each of
IES Common Stock, WPLH Common Stock, IPC Common Stock and McLeod Class A  common
stock;  (vii) compared the  financial performance of  IES, WPLH and  IPC and the
prices and  trading activity  of IES  Common Stock,  WPLH Common  Stock and  IPC
Common Stock with that of certain other comparable publicly traded companies and
their  securities; (viii) reviewed  the financial terms,  to the extent publicly
available, of  certain  comparable  merger  or  acquisition  transactions;  (ix)
analyzed  the pro forma financial impact of the Mergers on IES; (x) participated
in discussions and negotiations among representatives  of IES, WPLH and IPC  and
their  respective  financial  and  legal  advisors;  (xi)  reviewed  the  Merger
Agreement, the  Stock Option  Agreements and  certain related  documents;  (xii)
reviewed  and discussed with IES, WPLH and IPC an analysis prepared by IES, WPLH
and IPC with the  assistance of a  third-party consultant to  IES, WPLH and  IPC
regarding estimates of the amount and timing of the potential cost savings to be
derived  from the Mergers;  (xiii) reviewed the  amended registration statements
filed by McLeod on Form S-1, dated May 15, 1996 and June 10, 1996, respectively,
as well as the  Investor Agreement among various  parties including McLeod,  IES
Investments Inc., Midwest Capital Group Inc., MWR Investments Inc. and Clark and
Mary  McLeod, entered into as of April  1, 1996, which, among other things, sets
forth certain restrictions on the transfer  of McLeod stock owned by IES;  (xiv)
reviewed  certain  information pertaining  to  McLeod and  McLeod's contemplated
initial public offering provided  by IES and discussed  certain aspects of  such
information  with the management of IES;  and (xv) performed such other analyses
and examinations  and considered  such other  factors as  Morgan Stanley  deemed
appropriate.
 
    In  rendering its  opinion, Morgan Stanley  assumed and  relied upon without
independent verification  the  accuracy  and  completeness  of  the  information
reviewed  by Morgan Stanley for the purposes of its opinion. With respect to the
financial projections and the estimates of potential cost savings to be  derived
from  the Mergers,  Morgan Stanley assumed  that such  projections and estimates
were reasonably  prepared  on  bases reflecting  the  best  currently  available
estimates and judgments of the future financial performance of each of IES, WPLH
and IPC, respectively, and of the amount and timing of such cost savings. Morgan
Stanley  did not make  any independent valuation  or appraisal of  the assets or
liabilities of IES, WPLH and IPC.  In addition, Morgan Stanley assumed that  the
Mergers will be consummated in accordance with the terms set forth in the Merger
Agreement, including, among
 
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<PAGE>
other things, that the Mergers will be accounted for as a "pooling-of-interests"
business  combination  in  accordance  with  United  States  generally  accepted
accounting principles  and  that the  Mergers  will  be treated  as  a  tax-free
reorganization  and/or  exchange, in  each case,  pursuant  to the  Code. Morgan
Stanley's opinion is necessarily based on economic, market and other  conditions
as in effect on, and the information made available to it as of, the date of its
opinion.
 
    In  arriving at its opinion, Morgan  Stanley assumed that in connection with
the receipt of all the necessary  regulatory and governmental approvals for  the
proposed  Mergers, no  restriction will  be imposed  that would  have a material
adverse effect  on the  contemplated  benefits expected  to  be derived  in  the
proposed Mergers. In addition, Morgan Stanley was not authorized to solicit, and
did  not solicit, interest from any party with respect to a merger with or other
business combination transaction involving  IES, or any of  its assets, nor  did
Morgan Stanley have any discussions or negotiations with any parties, other than
WPLH and IPC, in connection with the Mergers.
 
    The  following is  a brief summary  of certain analyses  performed by Morgan
Stanley and reviewed with the IES Board on November 10, 1995 in connection  with
Morgan Stanley's presentation and opinion to the IES Board on such date:
 
    COMPARABLE  PUBLICLY  TRADED COMPANY  ANALYSIS.   As  part of  its analysis,
Morgan Stanley compared  certain financial  information of  IES with  that of  a
group  of  publicly  traded electric  utility  companies,  including MidAmerican
Energy Company, Washington Water & Power,  and Delmarva Power and Light  Company
(collectively,  the "MS  IES Comparables")  and also  compared certain financial
information of WPLH  with that of  a group of  publicly traded electric  utility
companies, including Kansas City Power & Light, WPS Resources Corporation, Union
Electric,   Western   Resources,   CILCORP   Inc.,   Utilicorp   United,  CIPSCO
Incorporated, and IPALCO Enterprises (collectively, the "MS WPLH  Comparables").
Such financial information included price to LTM ended June 30, 1995, forecasted
1995 and forecasted 1996 earnings multiples, price to book value multiple, price
to  LTM operating  cash flow  multiple and  dividend yield.  In particular, such
analyses indicated that as  of November 7,  1995 and based  on a compilation  of
earnings projections by securities research analysts as of October 28, 1995, IES
and  WPLH traded at  11.8 and 17.1 times  historical LTM earnings, respectively,
12.6  and  13.6  times   forecasted  earnings  for   the  calendar  year   1995,
respectively,  12.1 and  13.0 times  forecasted earnings  for the  calendar year
1996, respectively, 1.35 and 1.58 times book value as of the quarter ended  June
30,  1995, respectively, 4.7  and 6.6 times historical  LTM operating cash flow,
respectively, and a 7.7% and a 6.3% dividend yield, respectively. Morgan Stanley
noted that,  based  on  a  compilation of  earnings  projections  by  securities
research  analysts as of  October 28, 1995,  the MS IES  Comparables and MS WPLH
Comparables traded in  a range  of 13.4  to 14.1 times  and 14.2  to 17.3  times
historical  LTM earnings, respectively, 12.2 to 12.8 and 12.6 to 14.9 times 1995
forecasted earnings, respectively,  12.2 to  12.4 and  12.5 to  13.6 times  1996
forecasted  earnings, respectively, and 1.33 to 1.50 and 1.53 to 1.95 times book
value as of the  quarter ended June  30, 1995, respectively, and  had a 6.9%  to
7.3% and a 5.6% to 6.3% dividend yield, respectively.
 
    TRADING  RATIO ANALYSIS.  Morgan Stanley also  reviewed the ratio of the IES
Common Stock to WPLH Common Stock trading prices over varying intervals of  time
over  the latest five years.  This ratio ranged from  approximately 0.86 to 0.92
and, based on the  closing price of  IES Common Stock and  WPLH Common Stock  on
November 7, 1995 of $27.13 and $30.63, respectively, the ratio was 0.89.
 
    CONTRIBUTION  ANALYSIS.  Morgan Stanley  analyzed the pro forma contribution
of each of IES, WPLH and IPC to Interstate Energy. Such analysis included, among
other things,  relative contributions  of revenues,  EBITDA, EBIT,  net  income,
operating  cash  flow  and  book  value at  or  over  various  time  periods. In
particular such analysis showed that IES, WPLH and IPC contributed approximately
41.9%, 42.1% and  16.0% of historical  LTM revenues, 44.0%,  39.7% and 16.3%  of
historical  LTM EBITDA,  46.8%, 37.8% and  15.4% of historical  LTM EBIT, 45.2%,
40.1% and 14.7% of historical LTM operating cash flow, respectively, and  41.8%,
45.2% and 13.0% of the projected net income for calendar year 1995, 41.4%, 45.5%
and  13.1% of the projected net income  for calendar year 1996, and 41.7%, 42.2%
and  16.1%  of  the  book  value,  as  of  the  quarter  ended  June  30,  1995,
respectively. Morgan
 
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Stanley  observed  that the  aforementioned  contribution percentages  implied a
range of exchange ratios between IES Common Stock and WPLH Common Stock of  0.88
to 1.30 and a range of implied exchange ratios between IPC Common Stock and WPLH
Common Stock of 0.93 and 1.32. Based on this analysis, Morgan Stanley calculated
mean and median implied exchange ratios between IES Common Stock and WPLH Common
Stock  of  1.06 and  1.04, respectively,  and mean  and median  implied exchange
ratios between  IPC  Common  Stock and  WPLH  Common  Stock of  1.12  and  1.18,
respectively. While the mean of exchange ratios between the IES Common Stock and
the  WPLH Common  Stock implied by  the relative contribution  of such companies
across the eight LTM  and forward operating statistics  analyzed is above  0.98,
the  IES Ratio does fall within the broad range implied by this methodology and,
in fact,  is higher  than the  mean  implied exchange  ratios suggested  by  the
relative  contributions  of  IES and  WPLH  for  three of  such  eight operating
statistics.
 
    DISCOUNTED CASH FLOW ANALYSIS.  Morgan Stanley performed DCF analyses of IES
and WPLH for the fiscal years ended 1995 through 1999 based on certain financial
projections prepared by  the respective managements  of each company.  Unlevered
free  cash flows  of each  company were  calculated as  net income  available to
common shareowners plus the aggregate of preferred stock dividends, depreciation
and amortization, deferred taxes, and other non-cash expenses and after-tax  net
interest expense less the sum of capital expenditures and investment in non-cash
working  capital. Morgan Stanley calculated terminal  values by applying a range
of perpetual growth rates to the normalized unlevered free cash flows in  fiscal
1999  from  1.0% to  2.0% and  0.5%  to 1.5%,  representing estimated  ranges of
long-term cash flow growth rates for  IES and WPLH, respectively. The  cash-flow
streams and terminal values were then discounted to the present using a range of
discount  rates  from  7.0% to  8.0%,  representing  an estimated  range  of the
weighted average  cost of  capital  for each  of IES  and  WPLH. Based  on  this
analysis, Morgan Stanley calculated median per share values for IES ranging from
$23.03 to $30.99 and for WPLH ranging from $32.63 to $35.59.
 
    DISCOUNTED  DIVIDEND ANALYSIS.  Morgan Stanley performed discounted dividend
analyses of IES and WPLH for the  fiscal years ended 1995 through 1999 based  on
certain  dividend  projections prepared  by the  respective managements  of each
company and  on a  compilation of  earnings projections  by securities  research
analysts  as of October  28, 1995. Morgan Stanley  calculated terminal values by
applying a range of terminal multiples to  the earnings per share in the  fiscal
year  1999  from  11.5  times  to  12.5 times  and  12.5  times  to  13.5 times,
representing estimated ranges of comparable forward price to earnings  multiples
for  IES and WPLH. The dividend streams and terminal values were then discounted
to the present using a range of discount rates from 9.0% to 10.0%,  representing
a  range of the estimated cost of equity for each of IES and WPLH. Based on this
analysis, Morgan Stanley calculated median per share values for IES ranging from
$27.27 to $31.75 and for WPLH ranging from $31.09 to $32.41.
 
    ANALYSIS OF  SELECTED  PRECEDENT  TRANSACTIONS.   Using  publicly  available
information,  Morgan Stanley reviewed  the following four  proposed or completed
transactions constituting mergers  of equals in  the electric utility  industry:
Southwestern  Public Service  Co. and Public  Service Co.  of Colorado, Northern
States Power  and  Wisconsin Energy  Corp.,  Iowa-Illinois Gas  &  Electric  and
Midwest  Resources,  and Iowa  Resources and  Midwest Energy  (collectively, the
"Electric Utility MOE Transactions"). Morgan Stanley compared certain  financial
and market statistics of the Electric Utility MOE Transactions. The mean premium
to  unaffected  market price  (I.E., the  market  price one  month prior  to the
announcement of the transaction) was 3.6%, the mean price to book value multiple
was 1.5 times, the mean  LTM price to earnings multiple  was 12.0 times and  the
mean  LTM operating cash  flow multiple was  5.3 times. Based  on this analysis,
Morgan Stanley  calculated per  share  values for  IES  ranging from  $24.78  to
$32.06.
 
    PRO  FORMA ANALYSIS OF THE  MERGERS.  Morgan Stanley  analyzed the pro forma
impact of the Mergers  on IES earnings  and dividends per  share for the  fiscal
years ended 1997 through 1999. Such analysis was performed utilizing stand-alone
earnings estimated for the fiscal years ended 1997
 
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through  1999  for IES,  WPLH  and IPC  based  on certain  financial projections
prepared by the respective managements of  each company and on a compilation  of
earnings  projections by securities research analysts, in each case, taking into
account the cost savings expected to be derived from the Mergers as estimated by
the managements of IES, WPLH and IPC.
 
    On April 29, 1996, at a meeting  of the IES Board, Morgan Stanley  discussed
and  reviewed with the IES  Board the proposed contingent  adjustment to the IES
Ratio relating  to  the  McLeod  Contingency. In  this  regard,  Morgan  Stanley
examined  the potential contributions  to the market price  of IES Common Stock,
based on the implied values for  such stake suggested by the estimated  offering
price  range as would be set forth in McLeod's amended registration statement on
Form S-1,  dated May  15, 1996,  taking into  account, among  other things,  the
following  factors: the execution risk involved in achieving a successful public
offering,  the   underlying  volatility   which  would   be  inherent   in   the
publicly-traded  McLeod Class A  common stock, given  the difference in industry
fundamentals and anticipated  shareholder profiles between  McLeod and IES;  the
depressing  effect an  exit (if permissible)  by one of  McLeod's three founding
shareholders would have on the initial public offering price; the illiquidity of
the IES  stake  in  light of  the  restrictions  on transfer  contained  in  the
Investment  Agreement; the taxes which  would likely be payable  by IES upon the
eventual sale of its McLeod common stock once the aforementioned restrictions on
transfer had lapsed; and  the fact that with  the adjusted 1.01 exchange  ratio,
IES  shareholders, through their pro forma ownership of Interstate Energy, would
effectively retain 42.1% of the value attributable to IES's ownership of  McLeod
shares.
 
    PRO  FORMA  OWNERSHIP.    Morgan  Stanley  compared  the  overall  aggregate
percentage share ownership  of the  combined company assuming  the Mergers  were
consummated  at the Ratios (assuming the IES Ratio was not adjusted to 1.01) and
the IES Ratio as  adjusted if the McLeod  Contingency was satisfied as  follows:
(i)  the holders  of IES Common  Stock would  own 41.3% of  the combined company
assuming the Mergers were consummated at the Ratios (assuming the IES Ratio  was
not  adjusted to 1.01)  compared to 42.1%  of the combined  company assuming the
Mergers were consummated at the IES Ratio as adjusted if the McLeod  Contingency
was  satisfied, (ii)  the holders of  WPLH Common  Stock would own  43.6% of the
combined company assuming the Mergers  were consummated at the Ratios  (assuming
the  IES  Ratio was  not adjusted  to 1.01)  compared to  43.0% of  the combined
company assuming the Mergers  were consummated at the  IES Ratio as adjusted  if
the  McLeod Contingency was satisfied and (iii)  the holders of IPC Common Stock
would own 15.1% of the combined company assuming the Mergers were consummated at
the Ratios (assuming the IES Ratio was  not adjusted to 1.01) compared to  14.9%
of  the combined company assuming the Mergers  were consummated at the IES Ratio
as adjusted if the McLeod Contingency was satisfied.
 
    UPDATED CONTRIBUTION  ANALYSIS.    Morgan Stanley  analyzed  the  pro  forma
contribution  of each of IES, WPLH and  IPC to Interstate Energy based primarily
on historical LTM financial information as of the quarter ended March 31,  1996.
Such  analysis included, among other  things, relative contributions of revenue,
EBITDA, EBIT, net income, operating cash flow and book value at or over  various
time  periods.  In  particular  such  analysis showed  that  IES,  WPLH  and IPC
contributed approximately  43.0%, 41.3%  and 15.6%  of historical  LTM  revenue,
45.1%,  42.3% and  12.6% of  historical LTM  EBITDA, 44.7%,  43.3% and  12.0% of
historical LTM EBIT,  42.4%, 43.0% and  14.6% of historical  LTM operating  cash
flow,  respectively, in each case,  LTM as of the  quarter ended March 31, 1996,
and 41.5%,  45.4% and  13.2% of  projected net  income for  calendar year  1996,
41.4%, 45.2% and 13.3% of projected net income for calendar year 1997 and 43.0%,
42.9%  and 14.1%  of the  book value, as  of the  quarter ended  March 31, 1996,
respectively. Morgan  Stanley  observed  that  the  aforementioned  contribution
percentages implied a range of exchange ratios between IES Common Stock and WPLH
Common  Stock of 0.87 to 1.10 and a  range of exchange ratios between IPC Common
Stock and WPLH  Common Stock of  0.89 to  1.22. Based on  this analysis,  Morgan
Stanley  calculated mean and  median implied exchange  ratios between IES Common
Stock and WPLH Common Stock of 0.99 and 1.02, respectively, and mean and  median
implied  exchange ratios between IPC Common Stock  and WPLH Common Stock of 1.01
and 1.02, respectively.
 
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    UPDATED PRO FORMA ANALYSIS OF THE MERGERS.  Morgan Stanley analyzed the  pro
forma  impact, taking into account the impact of the adjustment to the IES Ratio
upon satisfying the McLeod Contingency, of the Mergers on IES earnings per share
for the  fiscal years  ended  1997 through  1999.  Such analysis  was  performed
utilizing stand-alone earnings estimated for the fiscal years ended 1997 through
1999  for  IES, WPLH  and IPC  based  on certain  updating discussions  with the
respective managements  of  IES,  WPLH  and IPC  as  to  the  current  operating
environment  and  future business  prospects for  each such  company, and  as an
updated compilation of earnings projections by securities research analysts,  in
each  case, taking into account the cost savings expected to be derived from the
Mergers as estimated by the managements of IES, WPLH and IPC.
 
    The preparation  of a  fairness opinion  is  a complex  process and  is  not
necessarily  susceptible to  a partial  analysis or  summary description. Morgan
Stanley believes  that its  analyses must  be  considered as  a whole  and  that
selecting  portions  of its  analyses, without  considering all  analyses, would
create an incomplete view  of the process underlying  its opinion. In  addition,
Morgan  Stanley may have given  various analyses more or  less weight than other
analyses, and may  have deemed various  assumptions more or  less probable  than
other assumptions, so that the ranges of valuations resulting for any particular
analysis  described above should not be taken to be Morgan Stanley's view of the
actual value of IES, WPLH and IPC.
 
    In performing its  analyses, Morgan Stanley  made numerous assumptions  with
respect  to industry performance,  general business and  economic conditions and
other matters, many of which  are beyond the control of  IES, WPLH and IPC.  The
analyses  performed by Morgan  Stanley are not  necessarily indicative of actual
value, which may be significantly more or less favorable than suggested by  such
analyses.  Such  analyses  were  prepared solely  as  part  of  Morgan Stanley's
analysis of the fairness of  the IES Ratio, taking  into account the IPC  Ratio,
from  a financial  point of  view to the  holders of  IES Common  Stock and were
provided to the IES  Board in connection with  the delivery of Morgan  Stanley's
written  opinion dated the  date hereof confirming its  oral opinion of November
10, 1995. The analyses do not purport to be appraisals or to reflect the  prices
at  which IES, WPLH and  IPC might actually be  sold. Because such estimates are
inherently subject to  uncertainty, none of  IES, Morgan Stanley,  or any  other
person  assumes  responsibility for  their accuracy.  In addition,  as described
above, Morgan Stanley's  opinion and presentation  to the IES  Board was one  of
many   factors  taken  into  consideration  by  the  IES  Board  in  making  its
determination to approve the Mergers. Consequently, the Morgan Stanley  analyses
described  above should not be viewed as determinative of the opinion of the IES
Board or the view of management of either WPLH or IPC with respect to the  value
of  WPLH and IPC or of whether the IES  Board or the managements of WPLH and IPC
would have been willing to agree to a different exchange ratio.
 
    As part  of its  investment banking  business, Morgan  Stanley is  regularly
engaged in the valuation of businesses and securities in connection with mergers
and  acquisitions,  negotiated  underwritings,  competitive  biddings, secondary
distributions  of  listed  and  unlisted  securities,  private  placements   and
valuation  for estate, corporate  and other purposes. In  the ordinary course of
its business, Morgan Stanley and its affiliates may actively trade the debt  and
equity  securities  of IES,  WPLH  and IPC  for their  own  account and  for the
accounts of customers and,  accordingly, may at  any time hold  a long or  short
position  in such securities. In the past, Morgan Stanley has provided financial
advisory and  financing services  to IES  and WPLH,  for which  services  Morgan
Stanley  has received customary fees. Morgan Stanley acted as co-lead manager of
the McLeod initial public offering.
 
    Morgan Stanley has been retained by IES  to act as financial advisor to  IES
with  respect to the Mergers. Pursuant to a letter agreement dated June 30, 1995
between IES and Morgan  Stanley, Morgan Stanley is  entitled to (i) an  advisory
fee for its time and efforts expended in connection with the engagement which is
estimated to be between $100,000 and $250,000, which is payable in the event the
transaction  is not consummated,  (ii) an announcement  fee of $1,000,000, which
has been paid, and  (iii) a transaction  fee equal to  the product of  0.472562%
multiplied by the Aggregate Value of the transaction (as such term is defined in
such  letter agreement), or approximately $4,370,228, which is payable only upon
consummation  of  the  transaction.  Any  amounts  paid  or  payable  to  Morgan
 
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Stanley   as  advisory  or  announcement  fees  will  be  credited  against  the
transaction fee. IES has  agreed to reimburse Morgan  Stanley for its  expenses,
including  reasonable fees and expenses of  its counsel, and to indemnify Morgan
Stanley and its affiliates against  certain liabilities and expenses,  including
liabilities under federal securities laws.
 
    IPC'S FINANCIAL ADVISOR.  Salomon Brothers has acted as financial advisor to
IPC in connection with the Mergers. During the course of discussions regarding a
possible  transaction, Salomon  Brothers attended meetings  of the  IPC Board as
described in  "The Mergers  -- Background  of the  Mergers." At  such  meetings,
Salomon Brothers reviewed financial information concerning IPC, WPLH and IES and
provided  preliminary valuations. The financial  information reviewed by Salomon
Brothers at these meetings  was the same financial  information used by  Salomon
Brothers in arriving at its opinions (as updated through the relevant date), all
of  which  information  is  described  below.  The  results  of  the preliminary
valuations presented  by  Salomon  Brothers  at  such  IPC  Board  meetings  are
consistent  with  the results  utilized  by Salomon  Brothers  to arrive  at the
opinions of Salomon Brothers which results are described below.
 
    Salomon Brothers  delivered  to the  IPC  Board its  written  opinion  dated
November  10,  1995  to the  effect  that,  based upon  and  subject  to various
considerations set  forth  in such  opinion,  as of  such  date, the  IPC  Ratio
(without adjustment of the IES Ratio for satisfaction of the McLeod Contingency)
is fair to the holders of IPC Common Stock (other than WPLH, IES or any of their
respective  affiliates) from  a financial  point of  view. At  the May  10, 1996
meeting of  the IPC  Board, Salomon  Brothers reviewed  with the  IPC Board  the
proposed  contingent  adjustment  to  the  IES  Ratio  relating  to  the  McLeod
Contingency. Salomon  Brothers  advised  the  IPC Board  that  if  the  proposed
amendment  were adopted, Salomon Brothers could  render an opinion to the effect
that, based upon and subject to  various considerations that would be set  forth
in  such opinion, as of May 10, 1996,  the IPC Ratio (assuming adjustment of the
IES Ratio for satisfaction of the McLeod Contingency) is fair to the holders  of
IPC  Common Stock (other than  WPLH, IES or any  of their respective affiliates)
from a financial point of view.  In addition, Salomon Brothers has delivered  to
the  IPC  Board  its  written  opinion,  dated  the  date  of  this  Joint Proxy
Statement/Prospectus, to  the effect  that, based  upon and  subject to  various
considerations  set forth in such opinion, as  of such date, the IPC Ratio (with
the IES Ratio adjusted for the  satisfaction of the McLeod Contingency) is  fair
to  the  holders of  IPC Common  Stock (other  than  WPLH, IES  or any  of their
respective affiliates) from a financial point of view.
 
    THE FULL TEXT  OF SALOMON  BROTHERS' OPINION DATED  THE DATE  OF THIS  JOINT
PROXY  STATEMENT/PROSPECTUS,  WHICH  SETS FORTH  THE  ASSUMPTIONS  MADE, GENERAL
PROCEDURES FOLLOWED, MATTERS CONSIDERED AND LIMITS ON THE REVIEW UNDERTAKEN,  IS
ATTACHED AS ANNEX N TO THIS JOINT PROXY STATEMENT/PROSPECTUS AND IS INCORPORATED
HEREIN  BY  REFERENCE.  SALOMON  BROTHERS' OPINIONS  ARE  DIRECTED  ONLY  TO THE
FAIRNESS, FROM A FINANCIAL  POINT OF VIEW,  TO THE IPC  STOCKHOLDERS OF THE  IPC
RATIO  AND DO NOT ADDRESS  IPC'S UNDERLYING BUSINESS DECISION  TO ENTER INTO THE
MERGERS OR CONSTITUTE  A RECOMMENDATION TO  ANY IPC STOCKHOLDER  AS TO HOW  SUCH
STOCKHOLDER  SHOULD VOTE  WITH RESPECT TO  THE MERGER AGREEMENT.  THE SUMMARY OF
SALOMON BROTHERS'  OPINIONS SET  FORTH BELOW  IS QUALIFIED  IN ITS  ENTIRETY  BY
REFERENCE  TO THE FULL TEXT OF SALOMON  BROTHERS' OPINION DATED THE DATE OF THIS
JOINT PROXY STATEMENT/PROSPECTUS  ATTACHED AS ANNEX  N HERETO. IPC  STOCKHOLDERS
ARE  URGED TO, AND SHOULD,  READ THE OPINION CAREFULLY  AND IN ITS ENTIRETY. THE
OPINION DATED THE DATE OF THIS JOINT PROXY STATEMENT/PROSPECTUS IS SUBSTANTIALLY
SIMILAR TO THE SALOMON BROTHERS' OPINION DATED NOVEMBER 10, 1995.
 
    In arriving at its opinions, Salomon Brothers reviewed the Merger  Agreement
and  its related exhibits and, in the case of the opinion dated the date hereof,
this Joint Proxy  Statement/Prospectus. Salomon Brothers  also reviewed  certain
publicly available information relating to IPC, WPLH and IES, as well as certain
other information, including financial projections, provided to Salomon Brothers
by IPC, WPLH and IES. Salomon Brothers discussed the past and current operations
and financial condition and prospects of IPC, WPLH and IES with their respective
senior  management.  Salomon Brothers  also  considered such  other information,
financial studies, analyses, investigations and financial, economic, market  and
trading  criteria  as it  deemed  relevant, including  the  amended registration
statement filed by McLeod on Form S-1.
 
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<PAGE>
    Salomon Brothers assumed and  relied upon the  accuracy and completeness  of
the  information reviewed  by it  for the  purpose of  its opinions  and did not
assume any responsibility  for independent verification  of such information  or
for  independent evaluation or appraisal of the assets of IPC, WPLH or IES. With
respect to the  financial projections  of IPC,  WPLH and  IES, Salomon  Brothers
assumed  that they  had been  reasonably prepared  on bases  reflecting the best
currently available estimates and  judgments of the management  of IPC, WPLH  or
IES,  as the case may be, as to the future financial performance of such entity,
and Salomon Brothers expressed no opinion with respect to such forecasts or  the
assumptions on which they were based.
 
    Salomon  Brothers' opinions  were necessarily  based upon  business, market,
economic and other conditions as they existed on, and could be evaluated as  of,
the  respective  dates of  its  opinions and  did  not address  IPC's underlying
business decision to enter  into the Mergers or  constitute a recommendation  to
any  IPC stockholder as to how such  stockholder should vote with respect to the
Merger Agreement. Salomon Brothers  was not requested to,  and did not,  solicit
third party offers to acquire all or any part of IPC. Salomon Brothers' opinions
do not imply any conclusion as to the likely trading range for WPLH Common Stock
following  the consummation of  the Mergers, which may  vary depending on, among
other factors, changes  in interest  rates, dividend  rates, market  conditions,
general economic conditions and other factors that generally influence the price
of securities.
 
    The  following is  a summary of  the report (the  "Salomon Brothers Report")
presented by  Salomon  Brothers  to the  IPC  Board  on November  10,  1995,  in
connection with the delivery of the Salomon Brothers opinion dated such date. In
connection with the Salomon Brothers' opinion dated the date of this Joint Proxy
Statement/Prospectus,  Salomon Brothers performed  certain procedures, including
each of the financial analyses described  below, to update its analyses made  in
connection with the delivery of its opinion dated November 10, 1995 and reviewed
with  the managements of  IPC, WPLH and  IES the financial  information on which
such analyses  were based  and other  factors, including  the current  financial
results of such companies and the future prospects for such companies.
 
    COMPARABLE PUBLIC COMPANY ANALYSIS.  Salomon Brothers reviewed the financial
and  market performance of the following group of publicly traded utilities with
those of IPC: Black Hills Corporation, Central Louisiana Electric Company, Inc.,
Empire District Electric Company, Northwestern Public Service Company, Orange  &
Rockland  Utilities, Inc., Otter Tail Power Company and Sierra Pacific Resources
(collectively, the "SB IPC Comparable Group").  For IPC and each company in  the
SB  IPC Comparable Group, Salomon Brothers calculated multiples of Firm Value to
LTM EBIT  and  EBITDA and  to  property,  plant and  equipment  and  investments
("PP&E")  and multiples of  closing stock prices ("Stock  Price") at November 3,
1995, to book  value, LTM EPS  and 1995  and 1996 estimated  EPS. The  projected
results  were based on  published research reports  of certain analysts covering
the SB IPC Comparable Group. This analysis yielded the following multiple ranges
for the SB IPC Comparable  Group: Firm Value to LTM  EBIT (9.9x to 12.9x);  Firm
Value  to LTM EBITDA (7.1x to 8.8x); Firm  Value to PP&E (1.02x to 1.34x); Stock
Price to Book Value (1.32x to 2.17x);  Stock Price to LTM EPS (12.7x to  15.4x);
Stock  Price to  1995 estimated EPS  (11.8x to  14.9x); and Stock  Price to 1996
estimated EPS (11.5x  to 14.5x).  Salomon Brothers  also calculated  a range  of
dividend yields for the SB IPC Comparable Group of 4.8% to 7.2%.
 
    Salomon  Brothers performed the  same analysis for  WPLH using the following
group of  publicly  traded  utilities:  Duke Power  Company,  FPL  Group,  Inc.,
Northern   States  Power  Company,  Union  Electric  Company,  Wisconsin  Energy
Corporation and WPS Resources Corporation (collectively, the "SB WPLH Comparable
Group"). The analysis  yielded the  following multiple  ranges for  the SB  WPLH
Comparable  Group: Firm  Value to LTM  EBIT (9.9x  to 12.4x); Firm  Value to LTM
EBITDA (5.9x to 8.2x); Firm Value to PP&E (1.14x to 1.36x); Stock Price to  Book
Value  (1.66x to 1.98x); Stock Price to LTM  EPS (13.9x to 15.2x) Stock Price to
1995 estimated  EPS (13.4x  to 14.3x);  and Stock  Price to  1996 estimated  EPS
(13.0x  to 14.3x). The range of dividend yields for the SB WPLH Comparable Group
was 4.2% to 6.2%.
 
    For IES, Salomon  Brothers compared  the financial  and market  data of  the
following  group of  publicly traded utility  companies: Carolina  Power & Light
Company, Florida Progress Corporation,
 
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The Kansas  City  Power  &  Light Company,  MidAmerican  Energy  Company,  SCANA
Corporation  and Western Resources,  Inc. (collectively, the  "SB IES Comparable
Group"). Salomon Brothers calculated the  following ranges of multiples for  the
SB  IES Comparable Group: Firm Value to LTM EBIT (10.6x to 12.8x); Firm Value to
EBITDA (6.3x to 9.2x); Firm Value to PP&E (0.89x to 1.24x); Stock Price to  Book
Value  (1.39x to 1.97x); Stock Price to LTM EPS (13.3x to 16.9x); Stock Price to
1995 estimated  EPS (12.3x  to 14.6x);  and Stock  Price to  1996 estimated  EPS
(12.1x  to 14.0x). The dividend yield range  for the SB IES Comparable Group was
5.3% to 7.3%.
 
    COMPARABLE  TRANSACTION  ANALYSIS.    Salomon  Brothers  also  reviewed  the
consideration  paid or  proposed to  be paid  in recent  acquisitions of utility
companies.   Specifically,    Salomon    Brothers   reviewed    the    following
acquiror/acquiree transactions: PECO Energy Company/PP&L Resources, Inc. (1995);
Union  Electric Company/CIPSCO  Incorporated (1995);  Cincinnati Gas  & Electric
Company/ PSI Resources, Inc.  (1992); Entergy Corporation/Gulf States  Utilities
Company  (1992); IE Industries Inc. /Iowa Southern Utilities Company (1991); The
Kansas  Power  &   Light  Company/Kansas  Gas   and  Electric  Company   (1990);
PacifiCorp./Pinnacle  West  Capital  Corporation  (1989);  WPLH/Madison  Gas and
Electric Company (1989); SCEcorp./San Diego  Gas & Electric Company (1988);  The
Southern Company/Savannah Electric and Power Company (1987); and PacifiCorp/Utah
Power   &  Light  Company  (1987).  For  these  transactions,  Salomon  Brothers
calculated the following ranges of multiples of the aggregate value of each such
transaction to the aggregate market value of the acquiree one month prior to the
first indication that the acquiree is a merger candidate (1.23x to 1.65x, with a
median of 1.36x);  to the book  value of the  acquiree (1.14x to  2.34x, with  a
median of 1.78x); and to the acquiree's EPS for the trailing 12 months (11.1x to
20.3x,  with a  median of  14.8x). Salomon  Brothers applied  these multiples to
corresponding data for IPC  and calculated an implied  exchange ratio range  for
IPC Common Stock to WPLH Common Stock of 0.98 to 1.30.
 
    In  addition, Salomon Brothers reviewed the consideration paid or payable in
the following  mergers  of  equals: Baltimore  Gas  &  Electric  Company/Potomac
Electric  Power Company (1995); Public  Service Company of Colorado/Southwestern
Public Service Company  (1995); Northern States  Power Company/Wisconsin  Energy
Corporation (1995): Midwest Resources, Inc./Iowa-Illinois Gas & Electric Company
(1994);  Washington Water Power Company/Sierra Pacific Resources (1994); Midwest
Energy Company/Iowa  Resources Inc.  (1990); Fitchburg  Gas and  Electric  Light
Company/  UNITIL (1989);  and San Diego  Gas &  Electric Company/Tucson Electric
Power Company  (1988). For  these transactions,  Salomon Brothers  calculated  a
range  for the multiple of each  transaction's aggregate value to the acquiree's
aggregate market value of 1.00x to 1.21x (with a median of 1.00x). Based on that
data, Salomon Brothers calculated an implied exchange ratio of IES Common  Stock
to WPLH Common Stock of 0.88 to 1.06.
 
    DISCOUNTED  CASH  FLOW ANALYSIS.   Using  a  DCF analysis,  Salomon Brothers
estimated the present value of the future cash flows that each of IPC, WPLH  and
IES  could produce over  a five-year period  from 1995 through  1999, if each of
them were  to perform  on a  stand-alone  basis (without  giving effect  to  any
operating  or other  efficiencies pursuant  to the  Mergers) in  accordance with
forecasts developed  by the  managements  of IPC,  WPLH and  IES,  respectively.
Salomon  Brothers determined implied equity values for each of IPC, WPLH and IES
based upon the sum of (i) the aggregate discounted value (using various discount
rates ranging from 6.75% to 7.75%) of the five-year unleveraged free cash  flows
of  IPC, WPLH and IES, as the case may be, plus (ii) the discounted value (using
the same discount rate  range) of the sum  of (a) the product  of (x) the  final
year's  projected  net income  multiplied  by (y)  numbers  representing various
terminal or exit multiples (ranging  from 12.50x to 14.50x  for IPC and IES  and
from  13.00x to 15.00x  for WPLH) and  (b) the projected  net debt and preferred
equity in the final year.
 
    Utilizing this DCF analysis,  Salomon Brothers calculated  a range of  value
for  IPC Common Stock, WPLH Common Stock and IES Common Stock of $256 million to
$313 million, $944 million to $1,125 million and $877 million to $1,077 million,
respectively.
 
    CONTRIBUTION  ANALYSIS.     Salomon   Brothers   analyzed  the   pro   forma
contributions  from each of WPLH, IES and  IPC to the combined company, assuming
the Mergers are consummated as set forth in
 
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the Merger Agreement.  Salomon Brothers  analyzed, among other  things, in  each
case  for the fiscal years ending December 31, 1994, 1996 and 1997, the relative
contribution to  the combined  company  from each  of  WPLH's, IES's  and  IPC's
revenues,  EBITDA,  EBIT  and  net  income.  The  analysis  did  not  assume the
realization of any synergies in the Mergers or include any transaction costs  or
purchase  adjustments,  but did  assume that  pooling  accounting was  used. The
analysis determined that WPLH, IES and IPC would have contributed the  following
percentages  to the combined company's results in 1994: revenues -- 42.7%, 41.2%
and 16.1%, respectively; EBITDA -- 40.9%, 45.3% and 13.8%, respectively; EBIT --
40.5%, 46.0% and 13.5%, respectively; and net income -- 43.4%, 44.5% and  12.1%,
respectively.  Book value contributions at June 30, 1995, would have been 43.2%,
42.8%  and  14.0%  from  WPLH,   IES  and  IPC,  respectively.  Utilizing   this
contribution analysis, Salomon Brothers calculated implied exchange ratio ranges
for  IPC Common Stock to  WPLH Common Stock and IES  Common Stock to WPLH Common
Stock of 0.89 to 1.24 and 0.91 to 1.25, respectively.
 
    PRO FORMA MERGER CONSEQUENCES ANALYSIS.   Salomon Brothers analyzed  certain
pro  forma  effects on  WPLH, IPC  and IES  resulting from  the Mergers  for the
projected twelve-month periods  ending December  31, 1997, 1998  and 1999.  Such
analysis  was performed utilizing stand-alone earnings estimates prepared by the
respective managements of each company.
 
    EXCHANGE RATIO  ANALYSIS.    Salomon  Brothers  reviewed  and  analyzed  the
historical ratios of the daily closing prices of IPC Common Stock and IES Common
Stock  to WPLH Common Stock during the five-year period ending November 3, 1995.
The exchange ratios for the daily closing  per share prices of IPC Common  Stock
to  WPLH Common  Stock ranged  from a  low of 0.74  to a  high of  1.18, with an
average of 0.94. The exchange ratios for  IES Common Stock to WPLH Common  Stock
ranged from 0.73 to 1.19, with an average of 0.92.
 
    On  May 10, 1996, at  a meeting of the  IPC Board, Salomon Brothers reviewed
with the IPC Board the proposed contingent adjustment to the IES Ratio  relating
to  the  McLeod Contingency.  In this  regard,  Salomon Brothers  calculated the
potential contribution  of  the proceeds  of  McLeod's proposed  initial  public
offering, based on a range of possible final pricing terms for McLeod's proposed
initial  public offering, and compared the  percentage share ownership of former
holders of IPC Common  Stock of the combined  company assuming the Mergers  were
consummated at the Ratios (assuming the McLeod Contingency was not satisfied and
the IES Ratio was not adjusted to 1.01) and the adjusted IES Ratio (assuming the
McLeod  Contingency  was satisfied  and  the IES  Ratio  was adjusted  to 1.01).
Assuming  the  McLeod  Contingency  was  not  satisfied  and  the  Mergers  were
consummated  at the Ratios (with the IES Ratio not adjusted to 1.01), the former
holders  of  IPC  Common  Stock  would  own  15.1%  of  the  combined   company.
Alternatively,  assuming the McLeod Contingency was satisfied and the IES Merger
was consummated at  the adjusted  IES Ratio, the  former holders  of IPC  Common
Stock  would own 14.9%  of the combined  company. Additionally, Salomon Brothers
reviewed a range of potential values  attributable to IES's ownership of  McLeod
shares  and the allocation of those values  among WPLH, IES and IPC assuming the
Mergers were consummated at the Ratios (without the IES Ratio being adjusted for
the McLeod Contingency)  in comparison  to the allocation  assuming the  Mergers
were  consummated and the IES Ratio was  adjusted for satisfaction of the McLeod
Contingency. The analysis demonstrated that  if the value attributable to  IES's
ownership  of McLeod  shares reflected  in the  combined company's  market value
exceeded approximately  $26.6  million, the  adjustment  of the  IES  Ratio  for
satisfaction  of the McLeod  Contingency would not  result in a  decrease in the
market capitalization of the combined company attributable to IPC stockholders.
 
    In arriving at its opinions, in preparing the Salomon Brothers Report and in
reviewing the  McLeod  Contingency,  Salomon Brothers  performed  a  variety  of
financial  analyses, the  material portions of  which are  summarized above. The
summary set forth above  does not purport  to be a  complete description of  the
analyses  performed by Salomon Brothers or its presentation to the IPC Board. In
addition, Salomon Brothers believes  that its analyses must  be considered as  a
whole and that selecting portions of such analyses and the factors considered by
it,  without  considering  all  such  analyses  and  factors,  could  create  an
incomplete view of the process underlying its analyses set forth in the opinions
and in the Salomon Brothers Report. The  preparation of a fairness opinion is  a
complex  process  and  is not  necessarily  susceptible to  partial  analysis or
summary description. In
 
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addition, Salomon  Brothers  made  no  attempt to  assign  specific  weights  to
particular  analyses. With regard to the  comparable public company analysis and
the comparable acquisition analysis summarized above, Salomon Brothers  selected
comparable  public companies on the basis of various factors, including the size
of the public company and similarity of the line of business; however, no public
company or transaction utilized as a  comparison is identical to IPC, WPLH,  IES
or  the Mergers. Accordingly, an analysis  of the foregoing is not mathematical;
rather, it involves complex considerations and judgments concerning  differences
in financial and operating characteristics of the comparable companies and other
factors  that  could  affect the  acquisition  or  public trading  value  of the
comparable companies and transactions  to which IPC, WPLH,  IES and the  Mergers
are being compared.
 
    In  performing its analyses, Salomon Brothers made numerous assumptions with
respect  to  industry  performance,  general  business,  economic,  market   and
financial  conditions and other matters, many of which are beyond the control of
IPC, WPLH and IES. Any estimates contained in such analyses are not  necessarily
indicative   of  actual  past  or  future   results  or  values,  which  may  be
significantly more or less than such  estimates. Actual values will depend  upon
several  factors,  including  events  affecting  the  utility  industry, general
economic, market and interest rate conditions and other factors which  generally
influence  the price of securities.  Additionally, all projections and estimates
for future  results  of IPC,  WPLH  and IES  referred  to above  were  based  on
information provided by the respective managements of such companies.
 
    Salomon  Brothers is  an internationally recognized  investment banking firm
and regularly engages  in the valuation  of businesses and  their securities  in
connection  with mergers and acquisitions and  for other purposes. The IPC Board
selected Salomon  Brothers to  act as  its  financial advisor  on the  basis  of
Salomon  Brothers'  international reputation  and Salomon  Brothers' familiarity
with IPC and the utility industry. Salomon Brothers acted as underwriter for IPC
in connection with three of  its prior financings, as  well as lead manager  for
the  McLeod initial  public offering.  In the  ordinary course  of its business,
Salomon Brothers actively trades the debt and equity securities of IPC, WPLH and
IES for Salomon  Brothers' own account  and for the  accounts of customers  and,
accordingly,  may at any time hold a  long or short position in such securities.
The Ratios were determined by arms'-length negotiations among IPC, WPLH and IES,
in  consultation   with   their   respective  financial   advisors   and   other
representatives.
 
    Pursuant  to a  letter agreement dated  September 13, 1995,  between IPC and
Salomon Brothers, Salomon Brothers agreed to act as financial advisor to IPC  in
connection  with the Mergers. IPC is obligated to pay Salomon Brothers a monthly
fee of $25,000 during the term of the engagement and an additional fee equal  to
the  product of 0.75%  multiplied by the aggregate  consideration paid for IPC's
common equity (approximately  $2,448,000). This  additional fee  is due  Salomon
Brothers  as follows: 25% contingent upon and payable following execution of the
Merger Agreement; 25% contingent upon and payable following approval by the  IPC
stockholders;  and  the  remainder  (less  all  monthly  fees  paid  or payable)
contingent upon and only payable following consummation of the Mergers. IPC also
agreed to reimburse Salomon Brothers for its reasonable out-of-pocket  expenses,
including  fees and disbursements of counsel,  and to indemnify Salomon Brothers
and its affiliates, their respective  directors, officers, agents and  employees
and  each person, if any, controlling Salomon  Brothers or any of its affiliates
against certain liabilities, including liabilities under the federal  securities
laws, relating to, or arising out of, its engagement.
 
    As  noted  under  the  caption  "The Mergers  --  Reasons  for  the Mergers;
Recommendations of the  Boards of  Directors," the fairness  opinion of  Salomon
Brothers was only one of many factors considered by the IPC Board in determining
to approve the Merger Agreement and the IPC Merger.
 
INTERESTS OF CERTAIN PERSONS IN THE MERGERS
 
    In  considering the recommendations of the WPLH Board, the IES Board and the
IPC Board with respect to the Mergers, shareowners should be aware that  certain
members  of  WPLH's, IES's  and IPC's  management and  Boards of  Directors have
certain interests in the Mergers that are in addition
 
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<PAGE>
to their interest, if any,  as shareowners of WPLH,  IES and IPC generally.  The
Boards  of Directors of each of WPLH, IES  and IPC were aware of these interests
and considered them, among other things,  in approving the Merger Agreement  and
the transactions contemplated thereby.
 
    EMPLOYMENT  AGREEMENTS.  The Employment Agreements with each of Messrs. Liu,
Davis, Stoppelmoor and Chase will become  effective only at the Effective  Time.
The Employment Agreements are described in greater detailed under "-- Employment
Agreements" below.
 
    SEVERANCE  ARRANGEMENTS.   Under  certain  severance arrangements  and other
employee agreements maintained, or entered into,  by each of WPLH, IES and  IPC,
certain  benefits may become vested, and certain payments may become payable, in
connection with the Mergers. WPLH  has employment and severance agreements  with
each  of  thirteen executives  of  WPLH and  certain  of its  subsidiaries which
provide these executives  with a measure  of security against  changes in  their
relationship  with WPLH and its subsidiaries in the event of a change in control
of WPLH. These agreements  provide that each executive  officer that is a  party
thereto  is entitled to benefits if, within five years after a change in control
of WPLH  (as defined  in  the agreements),  the  officer's employment  is  ended
through  (a) termination by  WPLH or its  subsidiaries, other than  by reason of
death or  disability  or  for cause  (as  defined  in the  agreements),  or  (b)
termination  by the  officer due  to a breach  of the  agreement by  WPLH or its
subsidiaries or a significant change  in the officer's responsibilities, or  (c)
in  the case of Mr.  Davis's agreement only, termination  by Mr. Davis following
the first anniversary of the change in control. The benefits provided under each
of the agreements include: (a) a cash  termination payment of one, two or  three
times  (depending  on which  executive  is involved)  the  sum of  the executive
officer's annual salary  and his or  her average annual  bonus during the  three
years  before  the termination  and (b)  continuation  for up  to five  years of
equivalent hospital, medical,  dental, accident, disability  and life  insurance
coverage  as in effect at  the time of termination.  The agreements also provide
the foregoing  benefits  in  connection  with  certain  terminations  which  are
effected in anticipation of a change in control. Each agreement provides that if
any portion of the benefits under the agreement or under any other agreement for
the  officer  would  constitute an  excess  payment  for purposes  of  the Code,
benefits will be reduced so that the officer will be entitled to receive $1 less
than the maximum  amount which he  or she could  have received without  becoming
subject to the 20% excise tax imposed by the Code on certain excess payments, or
which  WPLH may pay without the loss of deduction under the Code. The WPLH Board
has authorized that each of the foregoing agreements be amended to  specifically
provide that the consummation of the Mergers will constitute a change in control
in certain circumstances for purposes of the agreements.
 
    Based  on the compensation paid  to the executives in  1995 and assuming the
occurrence of  a  termination for  which  severance benefits  would  be  payable
following  a change of control  of WPLH, the maximum  amounts payable to each of
Messrs. Davis, Harvey, Protsch, Ahearn and Amato and all of the other executives
of WPLH  as  a  group  (eight persons)  under  their  employment  and  severance
agreements  would  be  $1,623,524, $745,524,  $745,704,  $737,310,  $577,962 and
$2,583,641, respectively.
 
    IES has severance agreements with  twelve of its and Utilities'  executives,
including  Mr. Liu, James E. Hoffman, Executive Vice President of Utilities, and
John F. Franz, Jr.,  Vice President of Utilities.  The severance agreements  run
for  terms of one year,  subject to automatic renewal  unless either party gives
notice of non-renewal to the  other party at least 60  days prior to the  annual
renewal  date. Each agreement provides for salary continuation and certain other
benefits in the event  the covered executive is  terminated within a  three-year
period  following a  change of  control of  IES. The  Mergers will  constitute a
change of  control  for  purposes  of each  of  the  IES  severance  agreements.
Specifically,  the agreements  provide that  following termination  of a covered
executive's employment, except terminations  for just cause, death,  retirement,
disability  or voluntary resignation (other than resignation for "good reason"),
the executive's salary will be  continued, at a level  equal to his salary  just
prior  to termination, for  a period ranging from  eighteen to thirty-six months
(depending on  the executive  involved  and, in  certain  cases, his  length  of
service). Additionally, certain benefits will be
 
                                       70
<PAGE>
continued  during  the applicable  severance period,  including life  and health
insurance, and the  executive will  continue to receive  annual incentive  award
payments  equal to the average annual incentive awards paid to executives of the
same or comparable  designation during the  three years prior  to the change  in
control. In the event the executive dies during the severance period, the salary
and  benefit payments described  above shall be payable  during the remainder of
the term to the executive's surviving  spouse or his estate. The executive  will
also  become immediately  vested and  entitled to  receive awards  of restricted
stock or other rights  granted to the executive  under IES' Long-Term  Incentive
Plan.  With respect to a covered executive who is age 56 or older at the time of
the change of control, the severance agreement further provides that the  change
of  control will cause the executive to  become fully vested in his supplemental
retirement plan benefit (his  "SERP"), and that if  the executive is  terminated
within  three years following the change of control, he will be able to commence
his SERP payments  on the  earlier of the  date he  attains age 65  or the  date
salary  continuation payments cease under  his severance agreement. With respect
to an executive who is under  age 56 at the time  of the change of control,  the
severance  agreement  further  provides  that upon  the  change  of  control the
executive will receive  an annuity with  a value  of six months'  salary if  the
executive has been employed by IES or Utilities for less than ten years, and one
year's salary otherwise.
 
    In  November 1995, IES approved certain amendments to the existing severance
agreements which will take effect no later than the next annual renewal of  each
agreement,  subject  to  each  executive's  execution  of  an  amended  form  of
agreement. The amendments to the severance agreement for Mr. Liu provides, among
other things,  that during  the  applicable severance  period  Mr. Liu  will  be
entitled  to receive payments equal  to the average value  of both the long-term
and the annual incentive awards received by executives of the same or comparable
designation during the three years prior to the change of control. In  addition,
the amendments for all covered executives provide reimbursement, in an aggregate
amount  not  to exceed  15%  of the  executive's  base salary,  for outplacement
services and  legal  fees incurred  by  the  executive in  connection  with  his
termination,  and  also  provide  severance benefits  in  the  event  of certain
employment terminations within 180 days prior to a change in control.
 
    The provisions  of  the  severance  agreement covering  Mr.  Liu  have  been
incorporated  into the Employment  Agreement to be executed  between Mr. Liu and
Interstate Energy in connection with  the Mergers (described below and  attached
as  Annex  H),  and  after  the Effective  Time  his  Employment  Agreement will
supersede his existing severance agreement.
 
    Based on the compensation  paid to the executives  in 1995 and assuming  the
occurrence  of  a  termination for  which  severance benefits  would  be payable
following a change in  control of IES,  the maximum amounts  payable to each  of
Messrs. Liu, Hoffman and Franz and all of the other executives of IES as a group
(nine  persons) under their severance  agreements would be $2,269,694, $549,614,
$297,696 and $3,146,135, respectively.
 
    Effective as of  November 8,  1995, IPC  entered into  agreements (the  "IPC
Severance  Agreements") providing certain severance benefits with nine executive
officers of IPC, including Messrs. Stoppelmoor and Chase (collectively, the "IPC
Executives"). The  IPC Severance  Agreements will  provide benefits  to the  IPC
Executives  whose employment  is terminated  under certain  circumstances at any
time within thirty-six months after the month  in which a change in control  (as
defined  in the IPC Severance Agreements) occurs.  The term of the IPC Severance
Agreements expires on December 31, 1998  and may be extended for additional  one
year  periods. However, the term of the IPC Severance Agreements will not extend
beyond the date on which the covered IPC Executive attains the age of sixty-two.
 
    The severance benefits described  below will be paid  if an IPC  Executive's
employment  is terminated after  a change in control  unless the termination is:
(i) by  IPC for  cause; (ii)  by the  IPC Executive  without "good  reason"  (as
defined in the IPC Severance Agreements); (iii) due to the retirement of the IPC
Executive;  (iv)  due to  the death  of the  IPC  Executive; or  (v) due  to the
disability of the IPC Executive. An IPC Executive's employment will be deemed to
have been terminated following a  change in control by  IPC without cause or  by
the    IPC    Executive    for    good    reason    if    the    IPC   Executive
 
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<PAGE>
reasonably demonstrates that the IPC Executive  was terminated either: (i) as  a
result  of the  request of  a person who  has entered  into a  change in control
agreement with IPC, or (ii) otherwise in connection with, as a result of, or  in
anticipation of, a change in control.
 
    The  severance benefits provided under  the IPC Severance Agreements consist
of: (i)  a cash  lump sum  payment of  up  to three  times the  sum of  the  IPC
Executive's  annual salary and his or her  average annual bonus during the three
years prior to the IPC Executive's termination of employment, (ii)  continuation
of  life, disability,  accident and health  insurance benefits  similar to those
that the IPC Executive  enjoyed prior to  the change in  control for thirty  six
months  after the  date of  termination, or if  sooner, until  the IPC Executive
reaches  the  age  of  sixty-two  years;  (iii)  outplacement  services  on   an
individualized  basis at  a level commensurate  with the  IPC Executive's status
with IPC; and (iv)  the immediate vesting of  all outstanding stock options  and
all shares of restricted stock.
 
    Mr.  Stoppelmoor  is not  expected  to receive  any  payments under  the IPC
Severance Agreements because  he has  already attained age  62. If  a change  in
control  were to  occur on  December 31,  1995 and  all covered  executives were
immediately terminated with each  such executive being  entitled to receive  the
full  benefits  provided  under  his IPC  Severance  Agreement,  the approximate
amounts that would be payable to certain  executive officers of IPC would be  as
follows:  Mr. Chase $467,000; Mr. Hamill  $321,000; and Mr. Troy $318,000; under
these assumptions,  which would  maximize the  benefits that  could be  received
under  the IPC Severance Agreements, the aggregate amount of all of the payments
that could be received by all of the executives covered under the IPC  Severance
Agreements would not exceed $2,800,000.
 
    BOARD  OF DIRECTORS.  As provided in  the Merger Agreement, at the Effective
Time, the Interstate Energy Board will consist of fifteen directors, six of whom
will be designated by WPLH, including
Mr. Davis, six of whom will be  designated by IES, including Mr. Liu, and  three
of  whom will be  designated by IPC, including  Mr. Stoppelmoor. See "Interstate
Energy Following the Mergers -- Management of Interstate Energy."
 
    INDEMNIFICATION.  Pursuant to the Merger  Agreement, to the extent, if  any,
not  provided  by an  existing right  of indemnification  or other  agreement or
policy, from  and after  the  Effective Time,  Interstate  Energy will,  to  the
fullest  extent permitted by applicable law, indemnify, defend and hold harmless
each person who was at,  or who has been  at any time prior  to the date of  the
Merger  Agreement,  or who  becomes  prior to  the  Effective Time,  an officer,
director or employee of WPLH, IES or IPC or any of their subsidiaries (including
New Utilities and New  IPC) against all  losses, expenses (including  reasonable
attorneys'  fees and  expenses), claims, damages  or liabilities  or, subject to
certain restrictions, amounts paid in settlement, (i) arising out of actions  or
omissions  occurring at or prior to the  Effective Time (and whether asserted or
claimed prior to,  at or after  the Effective Time)  that are in  whole or  part
based  on, or arising  out of, the fact  that such person is  or was a director,
officer or  employee  of  such party,  or  (ii)  based on,  arising  out  of  or
pertaining  to the transactions  contemplated by the  Merger Agreement. See "The
Merger Agreement -- Indemnification."
 
CERTAIN ARRANGEMENTS REGARDING THE DIRECTORS AND MANAGEMENT OF INTERSTATE ENERGY
FOLLOWING THE MERGERS
 
    In connection  with  the  Mergers,  the  Interstate  Energy  Board,  at  the
Effective  Time, will consist of fifteen persons, six of whom will be designated
by WPLH, including Mr. Davis, six of  whom will be designated by IES,  including
Mr. Liu, and three of whom will be designated by IPC, including Mr. Stoppelmoor.
The  Merger  Agreement  also  provides for  the  designation  of  certain senior
officers of Interstate Energy and its subsidiaries following the Effective Time.
See "Interstate  Energy  Following  the  Mergers  --  Management  of  Interstate
Energy."  In addition, the Merger Agreement  provides that during the three-year
period following  the  Effective  Time, certain  provisions  thereof  (including
provisions  relating to existing employee agreements, workforce matters, benefit
plans, stock option  and other  plans, certain officer  positions at  Interstate
Energy  and its subsidiaries and certain post-merger operations) may be enforced
on behalf of the officers, directors and employees of WPLH, IES and IPC, as  the
case  may be, by  the directors designated  by each of  such companies (or their
 
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<PAGE>
successors), respectively.  The Merger  Agreement also  provides such  directors
with the standing to enforce provisions relating to the composition of and other
matters  relating to the Interstate Energy Board  for as long as such provisions
are applicable, including the provisions governing the selection of each of  the
WPLH,  IES  and IPC  designated directors  until  the date  of the  third annual
meeting of  shareowners of  Interstate Energy  and the  provisions limiting  the
designation  of  employee directors  for a  period of  five years  following the
Effective Time.  Finally,  the  Merger Agreement  provides  that  the  directors
designated by WPLH will be entitled to enforce for a five-year period provisions
relating  to the  selection of  Mr. Davis as  the Chief  Executive Officer (and,
following Mr. Liu's retirement, as Chairman  of the Board) of Interstate  Energy
and his selection to serve in certain other capacities.
 
EMPLOYMENT AGREEMENTS
 
    The  forms of the Employment Agreements  for Messrs. Liu, Davis, Stoppelmoor
and Chase  are  attached  hereto  as Annexes  H  through  K,  respectively.  The
Employment Agreements will become effective only at the Effective Time.
 
    Pursuant  to Mr. Liu's Employment Agreement,  Mr. Liu will serve as Chairman
of Interstate Energy, for a period of two years following the Effective Time and
thereafter will  retire as  an officer  of Interstate  Energy, although  he  may
continue  to serve  as a director.  Under Mr. Davis's  Employment Agreement, Mr.
Davis will, following the Effective Time, serve as President and Chief Executive
Officer of Interstate Energy for a period of five years following the  Effective
Time  and, for the  three-year period following Mr.  Liu's retirement, Mr. Davis
will also  serve  as  Chairman  of  Interstate  Energy.  Following  the  initial
five-year  term of  Mr. Davis's  Employment Agreement,  the Employment Agreement
will automatically  renew for  successive one-year  terms, unless  either  party
gives  prior written  notice of  his or its  intent to  terminate the Employment
Agreement. Mr. Davis's Employment Agreement also provides that he serve as Chief
Executive Officer of each subsidiary of Interstate Energy during the  three-year
period  following the Effective Time and as  a director of such companies during
the term of his Employment  Agreement. Pursuant to Mr. Stoppelmoor's  Employment
Agreement,  Mr. Stoppelmoor will serve as Vice Chairman of Interstate Energy for
a period of two years following the Effective Time and thereafter will retire as
an officer  of  Interstate  Energy, although  he  may  continue to  serve  as  a
director.  The provisions of the Employment  Agreements for each of Messrs. Liu,
Davis and  Stoppelmoor which  relate to  such persons  serving as  directors  of
Interstate  Energy  assume  that such  persons  are, to  the  extent applicable,
reelected and not  removed from the  Interstate Energy Board  by the  Interstate
Energy shareowners. Pursuant to Mr. Chase's Employment Agreement, Mr. Chase will
serve  as  President of  IPC  or New  IPC,  as the  case  may be,  following the
Effective Time  and  until  the  last day  of  the  calendar  month  immediately
following the calendar month in which Mr. Chase attains age 62.
 
    Mr.  Liu's Employment Agreement provides that he will receive an annual base
salary of not less than $400,000,  and supplemental retirement benefits and  the
opportunity  to earn short-term and  long-term incentive compensation (including
stock options, restricted stock and  other long-term incentive compensation)  in
amounts  no less than he  was eligible to receive  from IES before the Effective
Time. Pursuant to Mr.  Davis's Employment Agreement, he  will be paid an  annual
base  salary  not  less than  his  aggregate  annual salary  from  WPLH  and its
subsidiaries as in effect immediately prior  to the Effective Time ($450,000  as
of January 1, 1996). Mr. Davis will also have the opportunity to earn short-term
and  long-term incentive compensation (including stock options, restricted stock
and other  long-term incentive  compensation) in  amounts no  less than  he  was
eligible  to  receive  before  the  Effective  Time,  as  well  as  supplemental
retirement benefits  (including continued  participation in  the WP&L  Executive
Tenure  Compensation Plan) in an amount no  less than he was eligible to receive
before the Effective Time and life insurance providing a death benefit of  three
times  his annual salary. Under Mr.  Stoppelmoor's Employment Agreement, he will
receive an  annual base  salary  of not  less  than $300,000,  and  supplemental
retirement  benefits  and  the  opportunity  to  earn  short-term  and long-term
incentive compensation  (including stock  options,  restricted stock  and  other
long-term  incentive compensation)  in amounts no  less than he  was eligible to
receive from  IPC  before  the  Effective  Time.  Mr.  Stoppelmoor's  Employment
Agreement also provides that, following his
 
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retirement  as Vice Chairman of the Board of Interstate Energy, he will serve as
a consultant to the Chief Executive Officer of Interstate Energy for a  one-year
period.  In consideration for his services as a consultant, Mr. Stoppelmoor will
be paid  a fee  of  $16,667 per  month and  will  be reimbursed  for  reasonable
expenses  incurred  in  the  performance of  such  services.  Under  Mr. Chase's
Employment Agreement, he will  receive an annual base  salary not less than  the
aggregate  annual  base salary  he  was paid  by  IPC immediately  prior  to the
Effective Time ($165,000  as of January  1, 1996). Mr.  Chase will also  receive
supplemental   retirement  benefits  and  will  have  the  opportunity  to  earn
short-term  and  long-term  incentive  compensation  (including  stock  options,
restricted  stock  and other  long-term  compensation) offered  to  other senior
executive officers of Interstate Energy and  its affiliates in amounts not  less
than he was eligible to receive from IPC before the Effective Time.
 
    If  the  employment of  any of  the officers  with Employment  Agreements is
terminated without cause  (as defined in  the Employment Agreements)  or if  any
officer  terminates his employment for good reason (as defined in the Employment
Agreements), Interstate Energy or  its affiliates will  continue to provide  the
compensation  and  benefits called  for by  the respective  Employment Agreement
through the  end  of the  term  of  such Employment  Agreement  (with  incentive
compensation based on the maximum potential awards or, in the case of Mr. Chase,
on  the average awards received during the prior three years, and with any stock
compensation paid  in  cash), and  all  unvested stock  compensation  will  vest
immediately.  If  the  officer  dies  or  becomes  disabled,  or  terminates his
employment without good  reason, during  the term of  the Employment  Agreement,
Interstate Energy or its affiliates will pay to the officer or his beneficiaries
or  estate all compensation earned through the date of death, disability or such
termination (including previously deferred  compensation and pro rata  incentive
compensation  based  upon  the  maximum potential  awards).  If  the  officer is
terminated for cause,  Interstate Energy  or its  affiliates will  pay his  base
salary   through  the   date  of   termination  plus   any  previously  deferred
compensation. Notwithstanding the foregoing, in  the event that any payments  to
an officer under his Employment Agreement or otherwise are subject to the excise
tax  on excess parachute payments under the  Code, then the total payments to be
made under the Employment Agreement will be  reduced so that the value of  these
payments  the officer  is entitled to  receive is  $1 less than  the amount that
would subject the officer to the excise tax.
 
CERTAIN FEDERAL INCOME TAX CONSEQUENCES
 
    GENERAL.  The  following is a  summary description of  the material  federal
income tax consequences of the Mergers and summarizes the respective opinions of
counsel  to  WPLH, IES  and IPC,  subject to  the following  qualification. This
description summarizes the  opinion of Foley  & Lardner, counsel  to WPLH,  only
insofar  as it  relates to  consequences of  the IES  Merger and  the IPC Direct
Merger (or the IPC Merger, if  applicable) to WPLH's shareowners, it  summarizes
the opinion of Winthrop, Stimson, Putnam & Roberts, counsel to IES, only insofar
as   it  relates  to   consequences  of  the  IES   Merger  (and  the  Utilities
Reincorporation Merger, if applicable) to IES's shareholders, and it  summarizes
the  opinion of Milbank, Tweed, Hadley & McCloy, counsel to IPC, only insofar as
it relates to consequences of the IPC  Direct Merger (or the IPC Merger and  the
IPC  Reincorporation Merger, if applicable)  to IPC's stockholders. The opinions
summarized below are filed as exhibits to the Joint Registration Statement.
 
    This summary is not a complete description of all of the consequences of the
Mergers and, in particular,  may not address  federal income tax  considerations
that  may affect the treatment  of a shareowner that,  at the Effective Time, is
not a U.S. person or  is a tax-exempt entity or  an individual who acquired  IES
Common  Stock  or IPC  Common  Stock pursuant  to  an employee  stock  option or
otherwise as compensation. In addition, no information is provided with  respect
to  the tax consequences of the Mergers  under foreign, state or local laws. The
discussion is based on  the Code as in  effect on the date  of this Joint  Proxy
Statement/Prospectus,   without  consideration   of  the   particular  facts  or
circumstances of any  shareowner. CONSEQUENTLY,  EACH SHAREOWNER  IS ADVISED  TO
CONSULT  HIS, HER OR ITS OWN TAX ADVISOR  AS TO THE SPECIFIC TAX CONSEQUENCES TO
HIM, HER OR IT OF THE MERGERS.
 
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<PAGE>
    THE MERGERS.   The  respective  obligations of  the  parties to  effect  the
Mergers  are conditioned  on their  receipt of  certain additional  tax opinions
described in the remainder of this  paragraph and the following two  paragraphs.
The  WPLH obligation to effect the combined IES Merger and IPC Direct Merger (or
IPC Merger, if applicable) is conditioned on the delivery of an opinion to  WPLH
from  Foley &  Lardner, its counsel,  dated as  of the Closing  Date, based upon
certain  customary   representations   and  assumptions   set   forth   therein,
substantially  to the effect that, for federal  income tax purposes, each of the
IES Merger  and  the  IPC Direct  Merger  (or  the IPC  Merger,  if  applicable)
constitutes  a tax-free reorganization  within the meaning  of Section 368(a) of
the Code.
 
    The  IES  obligation   to  effect   the  IES  Merger   (and  the   Utilities
Reincorporation  Merger, if  applicable) is  conditioned on  the delivery  of an
opinion to IES from Winthrop, Stimson,  Putnam & Roberts, its counsel, dated  as
of   the  Closing  Date,  based   upon  certain  customary  representations  and
assumptions set forth  therein, substantially  to the effect  that, for  federal
income  tax purposes, the IES Merger  (and the Utilities Reincorporation Merger,
if applicable)  constitutes  a tax-free  reorganization  within the  meaning  of
Section 368(a) of the Code.
 
    The  IPC obligation to effect  the IPC Direct Merger  (or the IPC Merger and
the IPC Reincorporation Merger, if applicable) is conditioned on the delivery of
an opinion to IPC from Milbank, Tweed, Hadley & McCloy, its counsel, dated as of
the Closing Date, based upon  certain customary representations and  assumptions
set  forth therein,  substantially to  the effect  that, for  federal income tax
purposes, the IPC Direct Merger (or  the IPC Merger and the IPC  Reincorporation
Merger,  if applicable) constitutes a tax-free reorganization within the meaning
of Section 368(a) of the Code.
 
    Rulings will not be sought from  the Internal Revenue Service regarding  the
Mergers  and  the Internal  Revenue Service  may  disagree with  the conclusions
expressed in the opinions of counsel referred to above.
 
    Based on the foregoing, and subject in all events to the approval of the IPC
Charter Amendment by the IPC stockholders at the IPC Meeting, the following is a
summary of  the material  federal  income tax  consequences  of the  Mergers  as
described  in  the opinions  of  Foley &  Lardner,  Winthrop, Stimson,  Putnam &
Roberts and  Milbank, Tweed,  Hadley &  McCloy filed  as exhibits  to the  Joint
Registration Statement:
 
            (i)
            WPLH,  IES,  IPC and  Acquisition (and  New  IPC, Utilities  and New
            Utilities, if applicable) will each  be a party to a  reorganization
    within the meaning of Section 368(b) of the Code;
 
           (ii)
            No  gain or loss will be recognized by WPLH, IES, IPC or Acquisition
            (or New IPC, Utilities and New Utilities, if applicable) pursuant to
    the Mergers;
 
          (iii)
            No gain or  loss will  be recognized by  the holders  of IES  Common
            Stock  upon the  exchange of their  IES Common  Stock for Interstate
    Energy Common Stock pursuant to the IES Merger, except that a holder of  IES
    Common  Stock that receives cash  in lieu of a  fractional share interest in
    Interstate Energy Common  Stock will  recognize gain  or loss  equal to  the
    difference  between the  cash received  and the  tax basis  allocated to the
    fractional share interest.  Any gain  or loss  recognized by  a holder  will
    constitute  capital  gain or  loss if  such holder's  IES Common  Stock with
    respect to which gain or  loss is recognized is held  as a capital asset  at
    the Effective Time;
 
           (iv)
            A  holder of IES Common Stock  that receives cash for IES Dissenting
            Shares will recognize gain or  loss equal to the difference  between
    the  amount of such cash  and the tax basis  of such holder's IES Dissenting
    Shares. Any such gain or loss recognized by a holder will constitute capital
    gain or loss  if such  holder's IES Dissenting  Shares are  held as  capital
    assets at the Effective Time;
 
            (v)
            No  gain or  loss will  be recognized by  the holders  of IPC Common
            Stock upon the  exchange of  their IPC Common  Stock for  Interstate
    Energy  Common Stock pursuant to the IPC Direct Merger, except that a holder
    of IPC  Common  Stock that  receives  cash in  lieu  of a  fractional  share
    interest in Interstate Energy Common Stock will recognize gain or loss equal
    to the
 
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<PAGE>
    difference  between the  cash received  and the  tax basis  allocated to the
    fractional share interest.  Any gain  or loss  recognized by  a holder  will
    constitute  capital  gain or  loss if  such holder's  IPC Common  Stock with
    respect to which gain or  loss is recognized is held  as a capital asset  at
    the Effective Time;
 
           (vi)
            The  tax basis of  the Interstate Energy Common  Stock received by a
            holder of IES Common Stock or IPC Common Stock, as the case may  be,
    will  be the same as such holder's tax  basis in the IES Common Stock or IPC
    Common Stock that  was exchanged pursuant  to the IES  Merger or IPC  Direct
    Merger,  as  the case  may be,  reduced by  the tax  basis allocable  to any
    fractional share interest in Interstate Energy Common Stock with respect  to
    which cash is being received;
 
          (vii)
            The holding period of the Interstate Energy Common Stock received in
            the  IES  Merger or  IPC Direct  Merger,  as the  case may  be, will
    include the holder's holding period with respect to the IES Common Stock  or
    IPC Common Stock that was exchanged pursuant to the IES Merger or IPC Direct
    Merger,  as the case may be (PROVIDED that  such stock was held as a capital
    asset at the Effective Time);
 
         (viii)
            No gain or loss will be  recognized by the holders of IPC  Preferred
            Stock  under  the IPC  Direct Merger,  except that  a holder  of IPC
    Preferred Stock that receives cash for IPC Dissenting Shares will  recognize
    gain or loss equal to the difference between the amount of such cash and the
    tax  basis of  such holder's  IPC Dissenting Shares.  Any such  gain or loss
    recognized by a holder will constitute capital gain or loss if such holder's
    IPC Dissenting Shares are held as capital assets at the Effective Time;
 
           (ix)
            Assuming the  IPC  Reincorporation Merger  and  the IPC  Merger  are
            effected,  no gain or loss will be  recognized by the holders of IPC
    Preferred Stock (other than  for holders of IPC  Dissenting Shares who  will
    incur  the tax treatment as described  in subparagraph (viii) above) and IPC
    Common Stock upon the  exchange of their IPC  Preferred Stock or IPC  Common
    Stock  for New IPC Preferred Stock or New  IPC Common Stock, as the case may
    be, pursuant to the IPC Reincorporation Merger, and no gain or loss will  be
    recognized by the holders of New IPC Common Stock upon the exchange of their
    New  IPC Common Stock for Interstate Energy Common Stock pursuant to the IPC
    Merger, except that a holder of New  IPC Common Stock that receives cash  in
    lieu  of a fractional share interest  in Interstate Energy Common Stock will
    recognize gain or loss equal to the difference between the cash received and
    the tax basis allocated to the  fractional share interest. Any gain or  loss
    recognized by a holder will constitute capital gain or loss if such holder's
    New  IPC Common Stock  with respect to  which gain or  loss is recognized is
    held as a capital asset at the Effective Time;
 
            (x)
            Assuming the  IPC  Reincorporation Merger  and  the IPC  Merger  are
            effected,  the tax basis of  the New IPC Preferred  Stock or New IPC
    Common Stock received by a holder of IPC Preferred Stock or IPC Common Stock
    will be the same as  such holder's tax basis in  the IPC Preferred Stock  or
    IPC  Common Stock  that was  exchanged pursuant  to the  IPC Reincorporation
    Merger, and the tax basis of the Interstate Energy Common Stock received  by
    a holder of New IPC Common Stock will be the same as such holder's tax basis
    in the New IPC Common Stock that was exchanged pursuant to the IPC Merger;
 
           (xi)
            Assuming  the  IPC Reincorporation  Merger  and the  IPC  Merger are
            effected, the holding period of the  New IPC Preferred Stock or  New
    IPC  Common Stock received by a holder  of IPC Preferred Stock or IPC Common
    Stock will  include the  holder's holding  period with  respect to  the  IPC
    Preferred  Stock or IPC Common Stock that  was exchanged pursuant to the IPC
    Reincorporation Merger,  and the  holding period  of the  Interstate  Energy
    Common  Stock received by a holder of  New IPC Common Stock will include the
    holder's holding period with  respect to the New  IPC Common Stock that  was
    exchanged  pursuant to  the IPC  Merger (PROVIDED,  in each  case, that such
    stock was held as a capital asset at the Effective Time); and
 
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<PAGE>
          (xii)
            No gain or  loss will  be recognized by  a shareowner  of WPLH  upon
            consummation of the Mergers.
 
ACCOUNTING TREATMENT
 
    The  Mergers will be  treated by the  parties as a  pooling of interests for
accounting and financial  reporting purposes. Under  this method of  accounting,
the recorded assets and liabilities of WPLH, IES and IPC will be carried forward
to  the consolidated financial statements of Interstate Energy at their recorded
amounts; income of Interstate  Energy will include income  of WPLH, IES and  IPC
for  the entire fiscal year in which  the Mergers occur; and the reported income
of the separate corporations for prior periods will be combined and restated  as
income  of Interstate  Energy. The  receipt by each  of WPLH,  IES and  IPC of a
letter from their respective independent  accountants, stating that the  Mergers
will qualify as a pooling of interests, is a condition precedent to consummation
of  the  Mergers. Representatives  of  Arthur Andersen  LLP  are expected  to be
present at the WPLH Meeting and the IES Meeting and representatives of  Deloitte
&  Touche LLP are expected to be present at  the IPC Meeting and in each case to
be available to respond  to questions, and  will have an  opportunity to make  a
statement  if they desire to  do so. See "The  Merger Agreement -- Conditions to
Each Party's Obligation to Effect the Mergers" and "Unaudited Pro Forma Combined
Financial Information."
 
STOCK EXCHANGE LISTING OF INTERSTATE ENERGY COMMON STOCK
 
    Application will  be made  for the  listing on  the NYSE  of the  shares  of
Interstate  Energy Common Stock to be issued pursuant to the terms of the Merger
Agreement. The  listing  on  the NYSE  of  such  shares, subject  to  notice  of
issuance,  is a condition precedent to the  consummation of the Mergers. So long
as WPLH, IES and IPC continue to meet the requirements of the NYSE, WPLH  Common
Stock,  IES Common Stock and IPC Common Stock, as the case may be, will continue
to be listed on the NYSE until the Effective Time. So long as WPLH continues  to
meet  the  requirements of  the BSE,  the CSE  and the  PSE, the  other national
securities exchanges  which  list WPLH  Common  Stock, WPLH  Common  Stock  will
continue  to be listed on the  BSE, the CSE and the PSE.  So long as IES and IPC
continue to meet the requirements of the  CSE and the PSE, and IES continues  to
meet  the requirements of  the BSE and  the PhSE, the  other national securities
exchanges which list IES Common Stock and IPC Common Stock, IES Common Stock and
IPC Common Stock will continue to be listed on the CSE and the PSE, and the  IES
Common  Stock will  continue to  be listed on  the BSE  and the  PhSE, until the
Effective Time.
 
REDEMPTION OF UTILITIES PREFERRED STOCK
 
    If the Utilities Reincorporation Merger is necessary for regulatory reasons,
it is  currently  anticipated that  shares  of Utilities  Preferred  Stock  then
outstanding  will be  redeemed by  Utilities prior  to the  consummation of such
merger in order to avoid the need to obtain a class vote of the holders of  such
stock  to approve the Utilities Reincorporation Merger. The Amended and Restated
Articles of  Incorporation  of Utilities  provides  that the  three  outstanding
series of Utilities Preferred Stock (I.E., 4.30%, 4.80% and 6.10%) are currently
redeemable  in whole or in part  at the option of Utilities  at any time or from
time to time on not less than 30 days' notice at $51.00 per share for the  4.30%
Series, $50.25 per share for the 4.80% Series and $51.00 per share for the 6.10%
Series,  together, in each case, with an  amount equal to the accrued and unpaid
dividends to and including the date of redemption.
 
FEDERAL SECURITIES LAW CONSEQUENCES
 
    All shares of  Interstate Energy Common  Stock and New  IPC Preferred  Stock
(assuming the IPC Reincorporation Merger is effected) received by shareowners of
IES  and IPC in the  Mergers will be freely  transferable, except that shares of
Interstate Energy Common Stock and New  IPC Preferred Stock received by  persons
who  are deemed to be "affiliates" (as such term is defined under the Securities
Act) of WPLH, IES,  IPC or New IPC  prior to the Mergers  may be resold by  them
only  in transactions permitted by the resale provisions of Rule 145 promulgated
under the Securities Act (or  Rule 144, in the case  of such persons who  become
affiliates  of Interstate Energy or New IPC) or as otherwise permitted under the
Securities Act. Persons who may be deemed to be affiliates of Interstate Energy,
WPLH, IES,  IPC  or New  IPC  generally  include individuals  or  entities  that
control, are
 
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<PAGE>
controlled  by, or  are under  common control with,  such party  and may include
certain officers and directors of such party as well as principal shareowners of
such party. The Merger Agreement requires each  of WPLH, IES and IPC to use  all
reasonable  efforts  to  cause  each  of its  affiliates  to  execute  a written
agreement to the effect that such affiliate will not offer or sell or  otherwise
dispose  of (i)  any shares of  WPLH, IES,  IPC or Interstate  Energy during the
period beginning 30 days prior to  the Effective Time and continuing until  such
time  as results covering at least 30  days of post-Effective Time operations of
Interstate Energy have been  published or (ii) any  of the shares of  Interstate
Energy  Common Stock or New  IPC Preferred Stock issued  to such affiliate in or
pursuant to the  Mergers in violation  of the  Securities Act or  the rules  and
regulations promulgated by the SEC thereunder.
 
    This  Joint Proxy Statement/Prospectus does  not cover resales of Interstate
Energy Common Stock or New IPC Preferred Stock received by any person who may be
deemed to be an affiliate of WPLH, IES, IPC, New IPC or Interstate Energy.
 
NO WISCONSIN DISSENTERS' RIGHTS
 
    The WBCL  does not  give WPLH  shareowners the  right to  dissent from,  and
obtain payment of the fair value of their shares in connection with, the matters
to be considered at the WPLH Meeting.
 
IOWA DISSENTERS' RIGHTS
 
    The  IBCA provides dissenters' rights for shareholders who object to the IES
Merger and  meet  the requisite  statutory  requirements contained  in  Sections
490.1301 through 490.1331 of the IBCA. Sections 490.1301 through 490.1331 of the
IBCA   are  reprinted  in  their  entirety  as  Annex  P  to  this  Joint  Proxy
Statement/Prospectus.
 
    The following discussion includes all material elements of the IBCA relating
to dissenters'  rights but  is not  a complete  statement of  the provisions  of
Sections  490.1301 through 490.1331 of the IBCA and is qualified in its entirety
by reference to Annex P hereto and to any amendments to such sections as may  be
adopted after the date of this Joint Proxy Statement/Prospectus. THIS DISCUSSION
AND  ANNEX P SHOULD BE REVIEWED CAREFULLY BY  ANY HOLDER OF IES COMMON STOCK WHO
WISHES TO EXERCISE STATUTORY  DISSENTERS' RIGHTS OR WHO  WISHES TO PRESERVE  THE
RIGHT  TO DO SO BECAUSE FAILURE STRICTLY TO COMPLY WITH THE PROCEDURES SET FORTH
HEREIN AND THEREIN WILL RESULT IN THE LOSS OF DISSENTERS' RIGHTS.
 
    A shareholder may dissent as to less than all of the shares of capital stock
registered in the  name of such  shareholder only if  such shareholder  dissents
with respect to all shares beneficially owned by any one person and notifies IES
in  writing  of  the  name and  address  of  each person  on  whose  behalf such
shareholder asserts dissenters' rights.  The rights of  a partial dissenter  are
determined  as  if the  shares  of capital  stock  as to  which  the shareholder
dissents and such shareholder's other shares of capital stock were registered in
the names  of  different  shareholders.  A  beneficial  shareholder  may  assert
dissenters'  rights as to shares held on  such shareholder's behalf only if such
shareholder (i) submits to IES the  record shareholder's written consent to  the
dissent  not later than the time  the beneficial shareholder asserts dissenters'
rights and (ii) asserts dissenters' rights with respect to all shares of capital
stock of which the shareholder is the beneficial shareholder or over which  such
beneficial shareholder has the power to direct the vote.
 
    The IBCA requires that a shareholder who wishes to assert dissenters' rights
(i)   deliver  to  IES,  before  the  vote  is  taken,  written  notice  of  the
shareholder's intent to  demand payment for  shares of common  stock if the  IES
Merger is consummated and (ii) not vote such shares of capital stock in favor of
the  Mergers. ANY SUCH NOTICE BY SHAREHOLDERS OF  IES MUST BE RECEIVED BY IES AT
IES TOWER, 200  FIRST STREET  S.E., CEDAR  RAPIDS, IOWA  52401, ATTENTION:  VICE
PRESIDENT, GENERAL COUNSEL AND SECRETARY, PRIOR TO SUCH VOTE. A vote against the
Merger  Agreement will not  satisfy the notice requirement.  The submission by a
shareholder of a blank proxy card or one voted in favor of the Merger  Agreement
(if not
 
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<PAGE>
revoked) will count as a vote in favor of the Merger Agreement and will serve to
waive  dissenters' rights. However, failure to return a proxy or to vote against
or abstain from voting will not serve to waive such rights.
 
    Within ten days after the date on which the Merger Agreement is approved  by
its  shareholders, IES must deliver  a written dissenters' notice  to all of its
shareholders that have  given a written  notice and  not voted in  favor of  the
Merger  Agreement in  accordance with  the preceding  paragraph. The dissenters'
notice will (i) state where the payment  demand must be sent and where and  when
certificates  for shares of capital stock must  be deposited, (ii) supply a form
for demanding payment that  includes the date of  the first announcement to  the
news  media or to shareholders of the terms of the proposed IES Merger and which
requires that the  shareholder asserting dissenters'  rights certify whether  or
not  such shareholder  acquired beneficial ownership  of the  shares before such
date, (iii) set a date by which IES must receive the payment demand, which  date
will  be not less than 30  nor more than 60 days  from the date such dissenters'
notice is delivered,  and (iv) be  accompanied by the  relevant sections of  the
IBCA.
 
    A  shareholder who has received a  dissenters' notice as described above and
who wishes to assert dissenters' rights must demand payment, certify whether the
shareholder acquired  beneficial ownership  of the  shares before  the date  set
forth  in the  dissenters' notice and  deposit the  certificate representing the
shares in accordance with the  terms of the notice.  A shareholder who does  not
demand  payment or deposit the  shareholder's share certificates where required,
each by the date set in the  dissenters' notice, is not entitled to payment  for
the shareholder's shares.
 
    Upon  receipt of  the payment  demand, or  at the  Effective Time, whichever
occurs later, Interstate Energy  must pay each  dissenting shareholder that  has
complied  with the provisions  of the IBCA  the amount estimated  to be the fair
value of the dissenter's shares, plus  accrued interest from the Effective  Time
to the date of payment at the average rate paid by Interstate Energy on its bank
loans  or,  if  none,  at a  rate  that  is  fair and  equitable  under  all the
circumstances. Such  payment  must  be accompanied  by  certain  financial  data
relating to Interstate Energy and other specified information as required by the
IBCA.  If the proposed IES Merger is not  effected within 60 days after the date
set for demanding  payment and  depositing the capital  share certificates,  IES
will  return the deposited  certificates and, if the  IES Merger is subsequently
effected, Interstate Energy  will deliver  a new  dissenters' notice  as if  the
corporate  action was taken without the vote  of the shareholders and repeat the
payment demand procedure. Interstate Energy may elect to withhold payment from a
dissenting shareholder  unless the  dissenting  shareholder was  the  beneficial
owner  of the shares before the date set  forth in the dissenters' notice as the
date of the  first announcement  of the  terms of  the proposed  IES Merger.  If
Interstate  Energy so elects  to withhold payment, it  must, after the Effective
Time, estimate the fair value of the  shares, plus accrued interest at the  rate
described  above,  and  pay  such amount  and  provide  certain  other specified
information as set  forth in the  IBCA to each  such dissenting shareholder  who
agrees to accept it in full satisfaction of the dissenter's demand.
 
    Shareholders considering seeking dissenters' rights should be aware that the
"fair  value"  of their  shares of  IES Common  Stock determined  under Sections
490.1301 through 490.1331 of the  IBCA could be more than,  the same as or  less
than the market value of such securities and that opinions of investment banking
firms as to fairness, from a financial point of view, may not provide a reliable
guide  to  fair  value under  Sections  490.1301  through 490.1331.  If  (i) the
dissenter believes that the amount offered or  paid is less than the fair  value
of  the dissenter's shares  or that the interest  due is incorrectly calculated,
(ii) Interstate Energy fails to make payment  within 60 days after the date  set
for  demanding payment, or (iii) IES, having  failed to effect the Mergers, does
not return the  deposited certificates  within 60 days  after the  date set  for
demanding  payment, dissenters may, within 30 days after the payment was made or
offered, notify Interstate Energy or IES, as the case may be, in writing of  the
dissenting  shareholder's own estimate of  the fair value of  the shares and the
amount of interest due, and demand payment of the fair value of such shares  and
interest so calculated less payments received by such dissenting shareholder, if
any.  A  dissenter waives  the  right to  demand  payment as  described  in this
paragraph unless the  dissenter notifies  Interstate Energy  of the  dissenter's
demand
 
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<PAGE>
within  30  days  after  Interstate  Energy  made  or  offered  payment  for the
dissenter's shares.  If demand  of a  dissenter for  payment remains  unsettled,
Interstate  Energy must (i) commence a proceeding in the Iowa District Court for
Linn County,  Iowa,  within  60  days after  receiving  the  payment  demand  to
determine  the fair value of the shares and accrued interest or (ii) pay to each
such dissenter the  amount demanded. The  costs of a  proceeding, including  the
reasonable  compensation and expenses of appraisers appointed by the court, will
generally be assessed against Interstate Energy. The court may, however,  assess
such  court  costs, including  the  fees and  expenses  of counsel  and experts,
against a  dissenter that  is found  by  the court  to have  acted  arbitrarily,
vexatiously or not in good faith in demanding payment.
 
DELAWARE DISSENTERS' RIGHTS
 
    In connection with the Mergers, holders of shares of IPC Preferred Stock are
entitled to appraisal rights under Section 262 of the DGCL ("Section 262") as to
shares  owned by them.  Section 262 is reprinted  in its entirety  as Annex Q to
this Joint  Proxy Statement/Prospectus.  All  references in  this summary  to  a
"stockholder"  are to the record holder of  the shares of IPC Preferred Stock as
to which appraisal rights are asserted. A person having a beneficial interest in
shares of IPC Preferred  Stock that are  held of record in  the name of  another
person,  such as  a broker  or nominee,  must act  promptly to  cause the record
holder to follow the steps summarized below  properly and in a timely manner  to
perfect whatever appraisal rights the beneficial owner may have.
 
    The  following discussion includes all material elements of the law relating
to appraisal  rights but  is not  a complete  statement of  such rights  and  is
qualified  in its entirety by reference to  Annex Q. THIS DISCUSSION AND ANNEX Q
SHOULD BE REVIEWED CAREFULLY BY ANY HOLDER OF IPC PREFERRED STOCK WHO WISHES  TO
EXERCISE STATUTORY APPRAISAL RIGHTS OR WHO WISHES TO PRESERVE THE RIGHT TO DO SO
BECAUSE  FAILURE STRICTLY  TO COMPLY  WITH THE  PROCEDURES SET  FORTH HEREIN AND
THEREIN WILL RESULT IN THE LOSS OF APPRAISAL RIGHTS.
 
    EACH STOCKHOLDER ELECTING TO  DEMAND THE APPRAISAL OF  HIS OR HER SHARES  OF
IPC  PREFERRED STOCK MUST DELIVER  TO IPC, BEFORE THE TAKING  OF THE VOTE ON THE
MERGERS AT THE IPC MEETING, A WRITTEN DEMAND FOR APPRAISAL OF HIS OR HER  SHARES
OF  IPC PREFERRED STOCK.  ANY SUCH STOCKHOLDER  MUST MAIL OR  DELIVER HIS OR HER
WRITTEN DEMAND TO THE SECRETARY OF IPC  AT 1000 MAIN STREET, DUBUQUE, IA  52001.
The written demand for appraisal must specify the stockholder's name and mailing
address,  the  number of  shares  of IPC  Preferred  Stock owned,  and  that the
stockholder is thereby demanding appraisal of his or her shares of IPC Preferred
Stock. BECAUSE THE HOLDERS OF IPC PREFERRED  STOCK WILL NOT VOTE ON APPROVAL  OF
THE MERGER AGREEMENT AND THE TRANSACTIONS CONTEMPLATED THEREBY, THE FAILURE OF A
HOLDER  OF IPC PREFERRED STOCK TO VOTE  AGAINST APPROVAL OF THE MERGER AGREEMENT
WILL NOT AFFECT  SUCH HOLDER'S ABILITY  TO DEMAND OR  PERFECT APPRAISAL  RIGHTS.
Appraisal rights will not be available under Section 262 if the stockholder does
not  continuously hold  through the Effective  Time the shares  of IPC Preferred
Stock with respect to  which he, she  or it demands  appraisal. Within ten  days
after  the Effective Time, IPC must provide  notice of the Effective Time to all
stockholders who have complied with Section 262.
 
    A demand for appraisal must be executed by or for the stockholder of record,
fully and correctly, as such stockholder's  name appears on the IPC  Certificate
or  Certificates. If the shares of IPC Preferred  Stock are owned of record in a
fiduciary capacity, such  as by a  trustee, guardian or  custodian, such  demand
must  be executed  by the fiduciary.  If the  shares of IPC  Preferred Stock are
owned of record by  more than one person,  as in a joint  tenancy or tenancy  in
common,  such demand must be executed by  all joint owners. An authorized agent,
including an agent  for two or  more joint  owners, may execute  the demand  for
appraisal  for a  stockholder of  record; however,  the agent  must identify the
record owner and  expressly disclose the  fact that, in  exercising the  demand,
such person is acting as agent for the record owner.
 
    A record owner, such as a broker, who holds shares of IPC Preferred Stock as
nominee  for others, may exercise appraisal rights with respect to the shares of
IPC Preferred Stock held for all or less than all beneficial owners of shares of
IPC  Preferred  Stock  as  to  which  such  person  is  the  record  owner.   In
 
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such  case  the  written demand  must  set forth  the  number of  shares  of IPC
Preferred Stock  covered by  such demand.  Where  the number  of shares  of  IPC
Preferred  Stock is not expressly  stated, the demand will  be presumed to cover
all shares of IPC Preferred Stock outstanding in the name of such record  owner.
Beneficial owners who are not record owners and who intend to exercise appraisal
rights  should instruct the  record owner to comply  strictly with the statutory
requirements with respect to the exercise of appraisal rights BEFORE the  taking
of the vote on the Mergers at the IPC Meeting.
 
    Within  120 days after the Effective  Time, either the surviving corporation
in the  IPC  Merger  or any  stockholder  who  has complied  with  the  required
conditions  of Section 262  may file a  petition in the  Delaware Chancery Court
demanding a determination of the value of the shares of IPC Preferred Stock.  If
a  petition for an appraisal is timely  filed, after a hearing on such petition,
the Delaware Chancery Court  will determine which  stockholders are entitled  to
appraisal  rights and will appraise  the shares of IPC  Preferred Stock owned by
such stockholders determining  the fair value  of such shares  of IPC  Preferred
Stock,  exclusive of  any element  of value  arising from  the accomplishment or
expectation of the IPC Merger, together with a fair rate of interest, if any, to
be paid upon the  amount determined to  be the fair  value. In determining  such
fair  value, the Delaware  Chancery Court is  to take into  account all relevant
factors. In  WEINBERGER V.  UOP INC.,  ET  AL., decided  February 1,  1983,  the
Delaware  Supreme  Court  discussed  the factors  that  could  be  considered in
determining fair value in an appraisal proceeding, stating that "proof of  value
by  any techniques or  methods which are generally  considered acceptable in the
financial community and otherwise admissible in court" should be considered  and
that  "fair  price  obviously  requires consideration  of  all  relevant factors
involving the value  of a company."  The Delaware Supreme  Court stated that  in
making  this determination of  fair value the court  must consider market value,
asset value, dividends, earnings prospects, the nature of the enterprise and any
other facts which could be ascertained as of the date of the merger which  throw
any  light on future  prospects of the merged  corporation. Section 262 provides
that fair value is  to be "exclusive  of any element of  value arising from  the
accomplishment  or  expectation  of  the merger."  In  WEINBERGER,  the Delaware
Supreme Court construed  Section 262  to mean  that "elements  of future  value,
including  the nature of the enterprise, which are known or susceptible of proof
as of  the date  of  the merger  and  not the  product  of speculation,  may  be
considered."
 
    Stockholders  considering  seeking appraisal  should have  in mind  that the
"fair value" of their shares of IPC Preferred Stock determined under Section 262
could be  more  than,  the same  as  or  less  than the  market  value  of  such
securities.  The  cost of  the  appraisal proceeding  may  be determined  by the
Delaware Chancery Court and taxed against  the parties as the Delaware  Chancery
Court  deems equitable  in the circumstances.  Upon application  of a dissenting
stockholder, the Delaware Chancery Court may order that all or a portion of  the
expenses incurred by any dissenting stockholder in connection with the appraisal
proceeding,  including without  limitation, reasonable  attorneys' fees  and the
fees and expenses  of experts,  be charged  pro rata  against the  value of  all
shares of IPC Preferred Stock entitled to appraisal.
 
    Within  120 days after the Effective  Time, any stockholder who has complied
with the requirements for exercise of  appraisal rights, as discussed above,  is
entitled, upon written request, to receive from the surviving corporation in the
IPC  Merger, or the IPC  Direct Merger, as the case  may be, a statement setting
forth the aggregate  number of  shares of IPC  Preferred Stock  with respect  to
which  demands for appraisal have been made  and the aggregate number of holders
of such shares. Such statement must be  mailed within 10 days after the  written
request  therefor  has been  received by  the surviving  corporation in  the IPC
Merger, or the IPC Direct Merger, as the case may be.
 
    Any stockholder who has duly  demanded appraisal in compliance with  Section
262  will not, from  and after the Effective  Time, be entitled  to vote for any
purpose the shares of IPC Preferred Stock  subject to such demand or to  receive
payment  of dividends  or other  distributions on  such shares  of IPC Preferred
Stock, except for dividends or  distributions payable to stockholders of  record
at a date prior to the Effective Time.
 
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<PAGE>
    At  any time within 60 days after  the Effective Time, any stockholder shall
have the right to  withdraw his or  her demand for appraisal  and to accept  the
terms  offered in the Mergers  whereby such holder will  obtain a like number of
shares of New IPC Preferred Stock if the IPC Reincorporation Merger is  effected
or  retain his or her shares of IPC  Preferred Stock if the IPC Direct Merger is
effected; after this period, the stockholder may withdraw his or her demand  for
appraisal  only with the consent of the  surviving corporation in the IPC Merger
or the IPC Direct Merger,  as the case may be.  If no petition for appraisal  is
filed with the Delaware Chancery Court within 120 days after the Effective Time,
stockholders'  rights to  appraisal shall  cease. Inasmuch  as IPC  will have no
obligation to file such a petition, and  has no present intention to do so,  any
stockholder  who desires such a petition to be  filed is advised to file it on a
timely basis. However, no petition timely  filed in the Delaware Chancery  Court
demanding  appraisal  shall  be  dismissed as  to  any  stockholder  without the
approval of the Delaware  Chancery Court, and such  approval may be  conditioned
upon  such terms as  the Delaware Chancery  Court deems just.  Any holder of IPC
Preferred Stock who effectively  withdraws his or her  demand for appraisal,  or
whose  right to  an appraisal  shall cease,  shall be  deemed to  have lost such
holder's appraisal rights.
 
                               REGULATORY MATTERS
 
    As indicated  below, consummation  of  the Mergers  is subject  to  numerous
regulatory  approvals, which are presently anticipated to be received during the
first half of  1997. Set forth  below is  a summary of  the material  regulatory
requirements affecting the Mergers.
 
STATE APPROVALS AND RELATED MATTERS
 
    WP&L is subject to the jurisdiction of the Wisconsin Commission with respect
to  retail utility service provided in Wisconsin.  WPLH and WP&L are each public
utility holding  companies  under the  Wisconsin  Holding Company  Act  and  are
subject  to  the  jurisdiction  of  the  Wisconsin  Commission.  A  wholly-owned
subsidiary of  WP&L  with utility  operations  in  Illinois is  subject  to  the
jurisdiction of the ICC with respect to its operations.
 
    Utilities  is currently subject to the  jurisdiction of the IUB with respect
to its utility operations  in Iowa. IPC  is subject to  the jurisdiction of  the
IUB, the ICC and the Minnesota Commission with respect to its utility operations
in Iowa, Illinois and Minnesota.
 
    Applications   for  approval  of  the   Mergers  and  related  transactions,
including, in the  case of certain  commissions, the issuance  of securities  in
connection  therewith,  were  initially  filed  in  early  March  1996  with the
Wisconsin Commission, the IUB, the ICC and the Minnesota Commission.
 
    Interstate Energy will  remain a  public utility holding  company under  the
Wisconsin Holding Company Act and will remain subject to the jurisdiction of the
Wisconsin  Commission. The following is a brief summary of certain provisions of
the Wisconsin Holding  Company Act  that will  continue to  apply to  Interstate
Energy after the Effective Time.
 
    The Wisconsin Holding Company Act prohibits any person from forming a public
utility holding company or acquiring or holding more than 10% of the outstanding
voting  securities  of  a  public  utility  holding  company,  without Wisconsin
Commission approval. The Wisconsin  Commission, if it finds  the capital of  any
public  utility affiliate will be  impaired by payment of  a dividend, may order
the utility  affiliate to  limit or  cease payment  of dividends  to the  public
utility holding company. Various transactions by a public utility affiliate with
others  in the public  utility holding company  system are prohibited, including
lending money, guaranteeing obligations, combined advertising, providing utility
service on terms  different from those  for other consumers  in the same  class,
and,  without Wisconsin Commission approval after establishment that the utility
affiliate will be paid  at fair market  value, certain sales  or leases of  real
property and use of services of utility employees. The Wisconsin Holding Company
Act  prohibits (i) any  public utility affiliate  from providing any non-utility
product or service in a manner or at a price that unfairly discriminates against
any competing  provider; (ii)  any non-utility  activity from  being  subsidized
materially   by   the  customers   of  any   public   utility  in   the  system;
 
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(iii) the  operation of  the system  in  any way  which materially  impairs  the
credit,  ability to  acquire capital on  reasonable terms or  ability to provide
safe, reasonable, reliable and adequate  utility service, of any public  utility
affiliate  in the system; (iv) any transfer by a public utility affiliate to any
other system company of any  confidential public utility information,  including
customer lists, for any non-utility purpose, unless the Wisconsin Commission has
approved  the transfer; and  (v) any termination  of the system's  interest in a
public utility affiliate without Wisconsin Commission approval. Other  statutory
provisions   which  pre-existed  the  Wisconsin   Holding  Company  Act  include
requirements for submission to the Wisconsin Commission for approval of  certain
contracts  or other arrangements  for furnishing property  or services between a
public utility and an affiliate.
 
    The Wisconsin Holding Company  Act also limits non-utility  diversification,
in  that,  stated  generally, the  net  book  value of  the  assets  (other than
investment in system affiliates)  of all non-utility  affiliates may not  exceed
the  sum of  25% of the  net book  value of the  assets of  all electric utility
affiliates and a percentage, to be  determined by the Wisconsin Commission  (but
not  less than 25%),  of the net  book value of  the assets of  all other public
utility affiliates. Based  on an  applicable review of  legislative history  and
principles  of statutory interpretation, WPLH, IES and IPC believe and intend to
take appropriate action to establish that the utility subsidiaries of Interstate
Energy following consummation  of the  Mergers will qualify  as "public  utility
affiliates"  of Interstate  Energy within the  meaning of  the Wisconsin Holding
Company Act. If, however, IPC and  Utilities, as presently constituted, were  to
be  deemed nonutility  affiliates (because they  are not  Wisconsin utilities or
Wisconsin corporations), the parties  reserve the right to  take such action  as
may  be required  to cause IPC  and Utilities  to be treated  as "public utility
affiliates" for  purposes  of  the  Wisconsin Holding  Company  Act.  Under  the
alternative structure set forth in the Merger Agreement, IPC and Utilities would
become   Wisconsin  corporations  and  acquire  certain  of  the  water  utility
operations currently  conducted  by WP&L  within  the State  of  Wisconsin.  The
parties  currently intend to seek regulatory approval to effect the transactions
under either structure.  Although the parties  believe that the  Mergers can  be
consummated  under either  or both structures  in compliance  with the Wisconsin
Holding Company Act, that statute has not been authoritatively construed, and no
assurance as to the interpretation of  the Wisconsin Holding Company Act can  be
given.
 
    In  addition,  the  Wisconsin  Holding Company  Act  requires  the Wisconsin
Commission to  periodically investigate  the impact  of the  operation of  every
holding  company system on every  public utility affiliate in  the system and to
determine whether each non-utility affiliate does, or can reasonably be expected
to do,  at least  one of  the following:  (i) substantially  retain, attract  or
promote  business activity or employment or provide capital to businesses within
the service territory of  any public utility affiliate  or certain others,  (ii)
increase  or promote energy  conservation or develop,  produce or sell renewable
energy products  or equipment,  (iii) conduct  a business  that is  functionally
related to the provision of utility service or to the development or acquisition
of  energy resources, and (iv) develop or operate commercial or industrial parks
in the service territory of any  public utility affiliate. WPLH and IES  believe
that  their  existing  non-utility  businesses  meet  the  requirements  of  the
Wisconsin Holding Company Act.  The Wisconsin Commission  also is authorized  to
order  a holding company to terminate its interest in a public utility affiliate
if the  Wisconsin  Commission  finds  that,  based  upon  clear  and  convincing
evidence,  termination of the  interest is necessary to  protect the interest of
utility investors in a financially healthy utility and the interest of consumers
in reasonably adequate utility service at a just and reasonable price.
 
    Given WPLH's experience  of operating  under the  Wisconsin Holding  Company
Act,  WPLH, IES and IPC do not  expect the restrictions of the Wisconsin Holding
Company Act  to  have  a  materially  adverse  effect  upon  the  operations  of
Interstate Energy following the Mergers.
 
    Under either transaction structure described above, IPC's utility operations
would  remain  subject to  regulation  by the  IUB,  the ICC  and  the Minnesota
Commission, Utilities' utility operations would remain subject to regulation  by
the  IUB and WP&L's utility operations would remain subject to regulation by the
Wisconsin Commission.  In addition,  under  the reincorporation  structure,  New
Utilities  and  New IPC  would  become Wisconsin  utilities  by virtue  of their
acquisitions of certain water
 
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utility properties from WP&L and would become subject to the jurisdiction of the
Wisconsin Commission  with  respect to  such  water utility  service.  Based  on
historical  experience  and  preliminary  discussions  with  the  staff  of  the
Wisconsin Commission, WPLH, IES and IPC believe that, under the  reincorporation
structure, the Wisconsin Commission would not seek to regulate activities of New
Utilities and New IPC following the Mergers other than those activities directly
related  to  the water  utility properties  and the  provision of  water utility
service in the State of Wisconsin.
 
PUBLIC UTILITY HOLDING COMPANY ACT OF 1935
 
    Interstate Energy is required to  obtain SEC approval under Section  9(a)(2)
of  the 1935 Act in connection with the Mergers. Section 9(a)(2) of the 1935 Act
provides that it  is unlawful  for any  person to  acquire any  security of  any
public  utility company if that  person owned, or by  virtue of that transaction
will come to own,  5% or more  of the voting securities  of that public  utility
company  and of any other public utility  company, without the prior approval of
the SEC. An application for approval of  the Mergers will be filed by WPLH,  IES
and IPC at the appropriate time. Under the applicable standards of the 1935 Act,
the  SEC is directed to approve a  proposed acquisition unless it finds that (i)
the acquisition  would  tend towards  detrimental  interlocking relations  or  a
detrimental  concentration  of control,  (ii) the  consideration  to be  paid in
connection with the acquisition is  not reasonable, (iii) the acquisition  would
unduly  complicate  the capital  structure  of the  applicant's  holding company
system or  would  be detrimental  to  the public  interest  or the  interest  of
investors  or consumers  or the  proper functioning  of the  applicant's holding
company system, or (iv) the acquisition  would violate applicable state law.  In
order  to  approve a  proposed  acquisition, the  SEC  must also  find  that the
acquisition would tend towards  the economical and  efficient development of  an
integrated  public utility system and would  otherwise conform to the 1935 Act's
integration and corporate simplification standards.
 
    WPLH is currently exempt from the registration and other requirements of the
1935 Act, other than from Section 9(a)(2)  thereof, pursuant to an order of  the
SEC  under Section  3(a)(1) of the  1935 Act.  The basis of  the exemption under
Section  3(a)(1)  is  that  WPLH   and  its  public  utility  subsidiaries   are
predominantly   intrastate   in  character   and   carry  on   their  businesses
substantially in a single state in which they are organized (Wisconsin). IES  is
also  currently exempt from the registration  and other requirements of the 1935
Act, other than from Section  9(a)(2) thereof, pursuant to  an order of the  SEC
under  Section 3(a)(1) of the 1935 Act. The basis of the exemption under Section
3(a)(1) is  that  IES and  its  public utility  subsidiaries  are  predominantly
intrastate  in character and carry on their businesses substantially in a single
state in which they are  organized (Iowa). IPC is  currently not subject to  the
requirements  of the 1935 Act because it is not a public utility holding company
within the definition of the 1935 Act. The Section 3(a)(1) exemption under which
WPLH and IES currently operate will not be available to Interstate Energy  after
consummation of the Mergers.
 
    Accordingly,  upon  consummation  of  the  Mergers,  Interstate  Energy must
register as a holding company under the 1935 Act. The 1935 Act imposes  numerous
restrictions  on  the  operations  of  a  registered  holding  company  and  its
subsidiaries and  affiliates. Subject  to limited  exceptions, SEC  approval  is
required  under the  1935 Act  for a  registered holding  company or  any of its
subsidiaries to: (i) issue securities, (ii) acquire utility assets from a  third
person,  (iii) acquire any securities of  another public utility, (iv) amend its
articles of incorporation, or (v)  acquire stock, extend credit, pay  dividends,
lend  money or invest in any manner  in any other businesses. SEC approval under
the 1935 Act also will be required for certain proposed transactions relating to
the Mergers. For example, SEC approval will be required for Interstate  Energy's
issuance  of securities pursuant to employee benefit plans and the establishment
of a service company to provide  various administrative and support services  to
Interstate  Energy and certain of its subsidiaries. The 1935 Act also limits the
ability of registered holding  companies to engage  in non-utility ventures  and
regulates holding company system service companies and the rendering of services
by  holding  company affiliates  to the  system's utilities.  WPLH, IES  and IPC
believe the foregoing restrictions  and limitations imposed by  the 1935 Act  in
its  current form may  limit possible operations  of Interstate Energy following
the Mergers. However,  WPLH, IES  and IPC believe  the benefits  of the  Mergers
exceed the potential adverse effects of such
 
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1935 Act regulation. In reaching this determination, WPLH, IES and IPC concluded
that  there are various  registered public utility  holding companies which have
operated successfully  within the  limitations imposed  under the  1935 Act.  In
addition, WPLH, IES and IPC considered existing initiatives to lessen the impact
of  the 1935 Act  and the legislation to  repeal the 1935 Act,  all of which are
discussed below.
 
    In addition, the SEC historically has  interpreted the 1935 Act to  preclude
registered holding companies, with limited exceptions, from owning both electric
and  gas  utility  systems.  Although  the  SEC  has  recently  recommended that
registered holding companies be  allowed to hold both  gas and electric  utility
operations  if the affected states  agree, it remains possible  that the SEC may
require as a condition  to its approval  of the Mergers that  WPLH, IES and  IPC
divest their gas utility properties and possibly certain non-utility ventures of
WPLH and IES within a reasonable time after the Mergers. In a few cases, the SEC
has  allowed  the  retention of  such  properties  or deferred  the  question of
divestiture  for  a  substantial  period  of  time.  In  those  cases  in  which
divestiture has taken place, the SEC has usually allowed enough time to complete
the  divestiture so as to allow the applicant to complete an orderly sale of the
divested assets. WPLH, IES and IPC  believe there are strong policy reasons  and
prior  SEC  decisions  which support  their  retention of  existing  gas utility
properties and non-utility ventures, or, alternatively, which support  deferring
the question of divestiture for a substantial period of time. Accordingly, WPLH,
IES and IPC will request in their 1935 Act application that Interstate Energy be
allowed  to retain, or, in the alternative,  that the question of divestiture be
deferred with respect to,  the existing gas  utility properties and  non-utility
ventures  of WPLH,  IES and IPC.  Should the  SEC deny this  request, a required
divestiture could, under certain circumstances, be at a price below fair  market
value or otherwise on terms deemed unsatisfactory by Interstate Energy and could
have  a  materially adverse  effect on  the  operations, earnings  and financial
condition of Interstate Energy.
 
    On June 20, 1995, the SEC issued  a series of new proposed regulations  that
are  designed, among other things, to ease the restrictions on and regulation of
the  activities  of  registered  holding  companies,  including  investment   by
registered  holding companies in  non-utility businesses. At  the same time, the
SEC's Division  of Investment  Management (the  "Division") issued  a report  of
legislative   and  administrative  recommendations,   including  the  Division's
preferred recommendation  that Congress  repeal  the 1935  Act, subject  to  the
transfer  of certain authority over the  books and records of registered holding
companies to  state  utility  commissions  and to  the  FERC.  The  report  also
recommended  liberalizing the  SEC's interpretation  of the  1935 Act  to permit
registered holding companies
to own both electric and gas  utility systems where the affected states  concur.
After  the  release  of the  report,  legislation  to repeal  the  1935  Act was
introduced  in  Congress  and  is  pending.  There  is  no  assurance  that  the
legislation  to repeal the 1935 Act will be enacted or that regulations proposed
by the  SEC  will  be  implemented  or that  the  recommendations  made  in  the
Division's  report  will be  adopted.  To the  extent that  some  or all  of the
regulations and recommendations  are implemented, however,  restrictions on  and
regulation  of Interstate Energy's activities may  be reduced or eliminated, and
Interstate Energy's ability to  retain ownership of  the gas utility  properties
and  some or all of the non-utility ventures currently operated by WPLH, IES and
IPC would be enhanced.
 
FEDERAL POWER ACT
 
    Section 203 of the Federal Power  Act provides that no public utility  shall
sell  or  otherwise dispose  of its  jurisdictional  facilities or,  directly or
indirectly, merge or consolidate such facilities with those of any other  person
or  acquire  any  security of  any  other  public utility  without  first having
obtained authorization from the  FERC. The approval of  the FERC is required  in
order to consummate the Mergers. Under Section 203 of the Federal Power Act, the
FERC  will approve a merger  if it finds the  merger "consistent with the public
interest." In reviewing a merger, the FERC generally has evaluated: (i)  whether
the  merger  will adversely  affect competition,  (ii)  whether the  merger will
adversely affect operating costs and rates, (iii) whether the merger will impair
the effectiveness of regulation, (iv) whether the purchase price is  reasonable,
(v)  whether  the  merger  is  the result  of  coercion,  and  (vi)  whether the
accounting treatment is reasonable.  It should be  noted, however, that  certain
FERC
 
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commissioners  have  called for  FERC to  reevaluate its  merger policy;  and it
cannot be predicted how any such reevaluation would affect the FERC's review  of
the  Mergers. On March 1,  1996, WPLH, IES and  IPC filed a combined application
with the FERC requesting that the FERC approve the Mergers under Section 203  of
the Federal Power Act (the "FERC Application"). Following the filing of the FERC
Application,   certain  parties,  including   several  consumer-owned  municipal
electric utilities,  intervened in  the FERC  proceeding. The  intervenors  have
raised  issues  regarding  their  access  to  transmission  facilities following
consummation of the  Mergers and  the impact of  the Mergers  on existing  power
supply  agreements.  It  is  presently  anticipated  that  such  issues  will be
favorably resolved and will not  adversely impact the FERC proceedings  relative
to  approval  of  the  Mergers.  Based  on  recent  FERC  proceedings  and prior
experience, WPLH,  IES and  IPC believe  that FERC  will reject  several of  the
issues  raised  by  the  intervenors  and  that  any  remaining  issues  will be
susceptible to successful resolution  through negotiations with the  intervening
parties.
 
    In   addition,  Utilities  and  IPC  hold  certain  certificates  of  public
convenience and necessity under  Section 7 of the  Natural Gas Act. The  Mergers
will  constitute  transfers  of  the  certificates  of  public  convenience  and
necessity, requiring approval from the FERC.
 
    Furthermore, prior  to  the IPC  Reincorporation  Merger and  the  Utilities
Reincorporation  Merger, if such mergers are to be effected, the approval of the
FERC under Section 204 of the Federal Power Act is required for New IPC and  New
Utilities to assume the debt of IPC and Utilities, respectively.
 
ANTITRUST CONSIDERATIONS
 
    The  HSR Act  and the rules  and regulations  promulgated thereunder provide
that certain transactions (including the  Mergers) may not be consummated  until
certain  information  has  been  submitted  to  the  Antitrust  Division  of the
Department  of  Justice  (the  "Antitrust  Division")  and  the  Federal   Trade
Commission  (the "FTC") and  specified HSR Act  waiting period requirements have
been satisfied.  On  June 7,  1996,  WPLH, IES  and  IPC filed  their  premerger
notification  forms pursuant  to the  HSR Act and  on July  7, 1996  the HSR Act
waiting period expired. The  expiration of the HSR  Act waiting period does  not
preclude  the  Antitrust Division  or the  FTC from  challenging the  Mergers on
antitrust grounds. However, neither WPLH, IES nor IPC believes that the  Mergers
will  violate federal antitrust laws. With the expiration of the waiting period,
there are  no remaining  federal antitrust  issues to  be resolved  in order  to
consummate  the Mergers.  If the  Mergers are  not consummated  within 12 months
after the expiration of the  initial HSR Act waiting  period, WPLH, IES and  IPC
would  be required to submit  new information to the  Antitrust Division and the
FTC, and  a new  HSR Act  waiting  period would  have to  expire or  be  earlier
terminated before the Mergers could be consummated.
 
ATOMIC ENERGY ACT
 
    Utilities  holds an NRC  operating license authorizing  Utilities to hold an
ownership interest  in  the  Duane  Arnold Energy  Center  and  to  operate  the
facility.  WP&L also holds an NRC operating  license authorizing WP&L to hold an
ownership interest  in  the Kewaunee  nuclear  generating facility.  The  Atomic
Energy  Act provides that no NRC license may be transferred, assigned, or in any
manner disposed of, directly or indirectly,  through transfer of control of  any
license  to any person unless  the NRC finds that  the transfer is in accordance
with the Atomic Energy Act and consents to the transfer. WPLH and IES will  seek
any approvals required from the NRC pursuant to the Atomic Energy Act to reflect
the  fact that  New Utilities or  Utilities, as the  case may be,  and WP&L will
continue to hold their existing  NRC licenses as operating company  subsidiaries
of Interstate Energy upon the consummation of the Mergers.
 
OTHER
 
    Utilities and IPC possess municipal franchises and environmental permits and
licenses  that may need  to be renewed or  replaced as a  result of the Mergers.
Utilities and IPC  do not  anticipate any difficulties  at the  present time  in
obtaining such renewals or replacements.
 
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GENERAL
 
    Under  the  Merger Agreement,  WPLH,  IES and  IPC  have agreed  to  use all
reasonable  efforts  to  obtain   all  necessary  material  permits,   licenses,
franchises  and  other  governmental authorizations  necessary  or  advisable to
consummate or  effect the  transactions contemplated  by the  Merger  Agreement.
Various parties may seek to intervene in these proceedings to oppose the Mergers
or  to have  conditions imposed upon  the receipt of  necessary approvals. While
WPLH, IES  and IPC  believe  that they  will  receive the  requisite  regulatory
approvals  for the Mergers, there  can be no assurance as  to the timing of such
approvals  or  the  ability  of  such  parties  to  obtain  such  approvals   on
satisfactory terms or otherwise.
 
    It  is a  condition to  the consummation  of the  Mergers that  final orders
approving the Mergers be obtained from the various federal and state  regulatory
bodies  described above on terms  and conditions which would  not have, or would
not be reasonably  likely to have,  a material adverse  effect on the  business,
assets,  financial condition, results  of operations or  prospects of Interstate
Energy or which  would be  materially inconsistent  with the  agreements of  the
parties  contained in the Merger  Agreement. There can be  no assurance that any
such approvals will not contain terms or conditions that cause such approvals to
fail to satisfy such  condition to the consummation  of the Mergers. Should  any
approvals  contain terms or conditions unsatisfactory  to WPLH, IES or IPC, such
party may waive  such condition to  consummation of, and  may proceed with,  the
Mergers.  Any determination to waive a condition would depend upon the facts and
circumstances existing at  the time  of such  waiver and  would be  made by  the
waiving  party's  Board of  Directors, exercising  its  fiduciary duties  to its
shareowners. Such facts and  circumstances may be different  than the facts  and
circumstances existing at the time the parties entered into the Merger Agreement
or at the time of the WPLH Meeting, the IES Meeting or the IPC Meeting and could
be more or less favorable to WPLH, IES, IPC or their respective shareowners than
such earlier facts and circumstances. No shareowner approval will be required or
sought  for  any  such  waiver,  and the  shareowners'  approval  of  the Merger
Agreement constitutes approval  of such waivers  as may be  granted by the  WPLH
Board, the IES Board or the IPC Board, as the case may be, in its discretion.
 
                              THE MERGER AGREEMENT
 
    The  following  is  a brief  summary  of  certain provisions  of  the Merger
Agreement, which is attached as Annex A and is incorporated herein by reference.
This summary is qualified in its entirety by reference to the Merger Agreement.
 
THE MERGERS
 
    The Merger Agreement  provides that,  following the approval  of the  Merger
Agreement  by the  shareowners of  WPLH, IES  and IPC,  and the  satisfaction or
waiver of the other conditions to the Mergers, including obtaining the requisite
regulatory approvals  and, if  the  Utilities Reincorporation  Merger is  to  be
effected,  the redemption of the then issued and outstanding shares of Utilities
Preferred Stock,  either  the IES  Merger  and the  IPC  Direct Merger  will  be
effected  or the IPC Reincorporation Merger, the  IES Merger, the IPC Merger and
the Utilities Reincorporation Merger will be effected.
 
    If the Merger Agreement is approved by the shareowners of WPLH, IES and IPC,
and the other conditions to the Mergers are satisfied or waived, the closing  of
the  Mergers  (the  "Closing")  will  take  place  on  the  second  business day
immediately following the date on which  the last of the conditions referred  to
below  under "-- Conditions to Each Party's  Obligation to Effect the Merger" is
fulfilled or  waived, or  at such  time  and date  as WPLH,  IES and  IPC  shall
mutually  agree (the "Closing Date"). On or  after the Closing Date, (i) the IES
Merger will become effective at the Effective Time, as specified in the articles
of merger filed by WPLH with the Secretaries of State of the States of Wisconsin
and Iowa and (ii) the IPC Direct  Merger will become effective at the  Effective
Time,  as specified in the articles of  merger filed by IPC with the Secretaries
of State of the States of Delaware  and Wisconsin. It is intended that both  the
IES  Merger and the  IPC Direct Merger  will be effected  simultaneously. If the
 
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IPC Reincorporation Merger and the  Utilities Reincorporation Merger are  deemed
by  the parties to be required for  regulatory purposes, (i) the IES Merger will
become effective at the time specified in  the articles of merger filed by  WPLH
with  the Secretaries of State of the States of Wisconsin and Iowa, (ii) the IPC
Reincorporation  Merger  will  become  effective  at  the  IPC   Reincorporation
Effective Time, as specified in the articles of merger and certificate of merger
filed  by New IPC with  the Secretaries of State of  the States of Wisconsin and
Delaware, (iii) the IPC  Merger will become effective  at the time specified  in
the articles of merger filed by New IPC with the Secretary of State of the State
of  Wisconsin,  and  (iv)  the  Utilities  Reincorporation  Merger  will  become
effective at the time specified in the articles of merger filed by New Utilities
with the Secretaries of State  of the States of Wisconsin  and Iowa. If the  IPC
Reincorporation  Merger  and  the  Utilities Reincorporation  Merger  are  to be
consummated, it  is  intended  that the  IES  Merger,  the IPC  Merger  and  the
Utilities  Reincorporation Merger would be effected simultaneously after the IPC
Reincorporation Effective Time.
 
    Subject to  the  condition that  the  opinions from  Merrill  Lynch,  Morgan
Stanley  and Salomon Brothers as to the fairness  of the IES Ratio and IPC Ratio
to WPLH  and  to  the  holders  of  IES  Common  Stock  and  IPC  Common  Stock,
respectively,  shall not have been  withdrawn, WPLH, IES and  IPC have agreed in
the Merger Agreement  to call, give  notice of,  convene and hold  a meeting  of
their  respective shareowners as soon as  reasonably practicable for the purpose
of securing their approval to the Mergers.
 
    CONSUMMATION OF THE MERGERS.  Upon the consummation of the Mergers:
 
    - Each share of  IES that  is owned  by IES,  WPLH or  IPC or  any of  their
      respective  subsidiaries ("IES  Cancelled Shares")  will be  cancelled and
      will cease to exist.
 
    - Each share of IPC or New IPC that is  owned by IES, WPLH or IPC or any  of
      their  respective subsidiaries ("IPC Cancelled  Shares") will be cancelled
      and will cease to exist.
 
    - Each issued and  outstanding share  of IES  Common Stock,  other than  IES
      Cancelled  Shares and  IES Dissenting Shares,  will be  converted into the
      right to  receive  1.01  shares  of Interstate  Energy  Common  Stock  (as
      adjusted  from 0.98 to reflect satisfaction  of the McLeod Contingency) in
      the IES Merger.
 
    - In the IPC Direct Merger, each issued and outstanding share of IPC  Common
      Stock,  other than IPC Cancelled Shares,  will be converted into the right
      to receive 1.11 shares of Interstate Energy Common Stock.
 
    - In the  IPC  Direct Merger,  each  issued  and outstanding  share  of  IPC
      Preferred  Stock,  other than  IPC  Dissenting Shares,  will  be unchanged
      (including with respect  to the  additional voting rights  proposed to  be
      approved at the IPC Meeting) as a result of the IPC Direct Merger and will
      remain outstanding thereafter.
 
    - IES   Dissenting  Shares  will  be   cancelled  and  converted  into  such
      consideration as may be  due with respect to  such shares pursuant to  the
      applicable  provisions of  the IBCA,  unless and  until the  right of such
      holder to receive fair value for such IES Dissenting Shares terminates  in
      accordance  with the IBCA, in which case  such shares will cease to be IES
      Dissenting Shares  and  will represent  the  right to  receive  Interstate
      Energy Common Stock pursuant to the Merger Agreement.
 
    - If  the  IPC  Reincorporation  Merger  is  consummated,  each  issued  and
      outstanding share of IPC  Common Stock, other  than IPC Cancelled  Shares,
      will be converted into an equal number of shares of New IPC Common Stock.
 
    - If  the  IPC  Reincorporation  Merger  is  consummated,  each  issued  and
      outstanding share  of  IPC  Preferred Stock,  other  than  IPC  Dissenting
      Shares,  will  be converted  into an  equal  number of  shares of  New IPC
      Preferred Stock.
 
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<PAGE>
    - If the IPC Merger is consummated, each issued and outstanding share of New
      IPC Common Stock,  other than  IPC Cancelled Shares,  will immediately  be
      converted  into  the right  to receive  1.11  shares of  Interstate Energy
      Common Stock.
 
    - If the IPC Merger is consummated, each issued and outstanding share of New
      IPC Preferred Stock, other than  IPC Dissenting Shares, will be  unchanged
      as a result of the IPC Merger and will remain outstanding thereafter.
 
    - IPC   Dissenting  Shares  will  be   cancelled  and  converted  into  such
      consideration as may be  due with respect to  such shares pursuant to  the
      applicable  provisions of  the DGCL,  unless and  until the  right of such
      holder to receive fair value for such IPC Dissenting Shares terminates  in
      accordance  with the DGCL, in which case  such shares will cease to be IPC
      Dissenting Shares and will either represent  the right to receive New  IPC
      Preferred  Stock or  remain as  IPC Preferred Stock,  as the  case may be,
      pursuant to the Merger Agreement.
 
    - If the Utilities  Reincorporation Merger is  consummated, each issued  and
      outstanding  share of  Utilities Common  Stock will  be converted  into an
      equal number of shares of New Utilities Common Stock.
 
    - Upon the conversions of the IES Common Stock in the IES Merger and the IPC
      Common Stock in the IPC Direct Merger or, in the alternative, the New  IPC
      Common Stock in the IPC Merger, except for IES Dissenting Shares, all such
      shares  of IES Common Stock and IPC  Common Stock or New IPC Common Stock,
      as the case may be, will be cancelled and cease to exist, and each  holder
      thereof  will cease to have rights  with respect thereto, except the right
      to receive the shares  of Interstate Energy Common  Stock and any cash  in
      lieu  of fractional shares of Interstate  Energy Common Stock to be issued
      in consideration therefor.
 
    - Each issued  and  outstanding  share  of WPLH  Common  Stock  will  remain
      outstanding  and unchanged as a  result of the Mergers  and will remain as
      one share of Interstate Energy Common Stock.
 
    Based upon the capitalization of WPLH, IES and IPC on November 10, 1995, and
the IES Ratio of 1.01 shares of Interstate Energy Common Stock per share of  IES
Common  Stock and the IPC Ratio of 1.11 shares of Interstate Energy Common Stock
per share of IPC  Common Stock, holders  of WPLH Common Stock,  as a group,  IES
Common  Stock, as  a group, and  IPC Common Stock,  as a group,  would have held
43.3%, 41.7% and 15.0% of the common equity of Interstate Energy if the  Mergers
had been consummated as of such date.
 
    Based  on the capitalization of WPLH, IES and  IPC on July 10, 1996, and the
IES Ratio and  the IPC  Ratio, holders  of WPLH Common  Stock, as  a group,  IES
Common Stock, as a group, and IPC Common Stock, as a group, would have held 43%,
42.2%  and 14.8% of  the common equity  of Interstate Energy  if the Mergers had
been consummated as of such date.
 
    If any holder of IES Common Stock  or IPC Common Stock would be entitled  to
receive  a number of  shares of Interstate  Energy Common Stock  that includes a
fraction, then in lieu of  a fractional share, such  holder will be entitled  to
receive  a cash  payment in an  amount determined by  multiplying the fractional
share interest by the average of the last reported sales price, regular way, per
share of WPLH Common Stock  on the NYSE for the  ten business days prior to  and
including  the last business day prior to  the Effective Time on which shares of
IES Common Stock  and IPC  Common Stock  were traded  on the  NYSE, without  any
interest thereon.
 
    As  soon  as  practicable  after  the  Effective  Time,  a  company mutually
acceptable to WPLH, IES and IPC (the "Exchange Agent") will mail to each  holder
of record of a Certificate which immediately prior to the Effective Time (or, if
applicable,  the  IPC  Reincorporation Effective  Time)  represented outstanding
shares of IES Common Stock  or IPC Common Stock  that were cancelled and  became
instead  the right  to receive  shares of Interstate  Energy Common  Stock and a
letter of transmittal and instructions for use in effecting the surrender of the
Certificates for certificates representing shares of
 
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<PAGE>
Interstate Energy Common Stock. Upon surrender of a Certificate to the  Exchange
Agent  for cancellation, together with a duly executed letter of transmittal and
such other documents, if any, as the  Exchange Agent may require, the holder  of
such  Certificate will  be entitled to  receive a  certificate representing that
number of whole shares of Interstate Energy Common Stock and any cash in lieu of
fractional shares of Interstate  Energy Common Stock which  such holder has  the
right  to  receive pursuant  to the  provisions of  the Merger  Agreement. Until
surrendered, each Certificate  will be deemed  at any time  after the  Effective
Time  to  represent only  the right  to receive  upon surrender  the certificate
representing shares of Interstate  Energy Common Stock and  cash in lieu of  any
fractional share of Interstate Energy Common Stock.
 
    The  letter of transmittal may, at  the option of Interstate Energy, provide
for the ability of a holder of one or more Certificates to elect that the shares
of Interstate Energy to  be received in  exchange for the  shares of IES  Common
Stock   and/or  IPC  Common  Stock  formerly  represented  by  such  surrendered
Certificates be issued in  uncertificated form or to  elect that such shares  be
credited  to an account established  for such holder under  the WPLH DRIP, which
will become the Interstate Energy DRIP following the Effective Time.
 
    No dividends or  other distributions  declared or made  after the  Effective
Time with respect to shares of Interstate Energy Common Stock with a record date
after  the  Effective Time  will  be paid  to  the holder  of  any unsurrendered
Certificate and no cash payment in lieu of fractional shares will be paid to any
such holder until such Certificate is surrendered. After such surrender, subject
to applicable law,  there will  be paid to  such holder,  without interest,  the
unpaid dividends and distributions, and any cash payment in lieu of a fractional
share, to which such holder is entitled.
 
    Certificates  which  immediately  prior to  the  Effective  Time represented
shares of  WPLH  Common Stock  need  not be  exchanged  and will  be  deemed  to
represent  a like number  of shares of  Interstate Energy Common  Stock from and
after the Effective Time. Certificates which immediately prior to the  Effective
Time  represented shares of IPC  Preferred Stock also need  not be exchanged and
will, except  for IPC  Dissenting Shares,  continue to  represent IPC  Preferred
Stock, or, if applicable, will be deemed to represent a like number of shares of
New IPC Preferred Stock, from and after the Effective Time.
 
    HOLDERS  OF IES COMMON STOCK  AND IPC COMMON STOCK  SHOULD NOT SEND IN THEIR
CERTIFICATES UNTIL THEY RECEIVE A LETTER OF TRANSMITTAL. SHAREOWNERS OF WPLH AND
HOLDERS OF IPC PREFERRED STOCK NEED NOT EXCHANGE THEIR CERTIFICATES.
 
SUBSIDIARIES AND JOINT VENTURES
 
    The Merger Agreement designates the majority-owned subsidiaries of WPLH, IES
and IPC,  respectively,  as "WPLH  Subsidiaries,"  "IES Subsidiaries"  and  "IPC
Subsidiaries"  (which  are  collectively  referred  to  as  "Subsidiaries"). The
remaining subsidiaries, joint venture interests and investments of WPLH, IES and
IPC are referred  to as  "WPLH Joint Ventures,"  "IES Joint  Ventures" and  "IPC
Joint  Ventures," respectively. The representations, warranties and covenants of
WPLH, IES and IPC in the Merger  Agreement apply only to the parties  themselves
and their Subsidiaries.
 
REPRESENTATIONS AND WARRANTIES
 
    The  Merger Agreement  contains customary representations  and warranties by
each of WPLH, IES and IPC relating to, among other things, (a) their  respective
organizations,  the organization  of their  respective Subsidiaries  and similar
corporate matters; (b) their  respective capital structures; (c)  authorization,
execution,  delivery, performance and enforceability of the Merger Agreement and
related matters; (d)  required regulatory approvals;  (e) their compliance  with
applicable  laws and agreements; (f) reports and financial statements filed with
the SEC and the  accuracy of information contained  therein; (g) the absence  of
any  material  adverse effect  on their  business, assets,  financial condition,
results of operations, or prospects; (h) the absence of adverse material  suits,
claims  or  proceedings,  and  other  litigation  issues;  (i)  the  accuracy of
information supplied  by  each  of WPLH,  IES  and  IPC for  use  in  the  Joint
Registration Statement of which this Joint Proxy Statement/
 
                                       90
<PAGE>
Prospectus  forms a  part; (j)  tax matters;  (k) retirement  and other employee
benefit plans and matters  relating to the  Employee Retirement Income  Security
Act  of 1974, as amended  ("ERISA"); (l) labor matters;  (m) compliance with all
applicable environmental laws, possession of all material environmental, health,
and safety permits and other environmental  issues; (n) the regulation of  WPLH,
IES  and IPC and their subsidiaries as public utilities in specified states; (o)
the shareowner vote  required in connection  with the Merger  Agreement and  the
transactions   contemplated  thereby   (as  set   forth  in   this  Joint  Proxy
Statement/Prospectus) being the only vote  required; (p) that neither WPLH,  IES
and  IPC or any of their respective affiliates  have taken or agreed to take any
action that would prevent  the Mergers as  being accounted for  as a pooling  of
interests; (q) the inapplicability of certain provisions of applicable state law
relating to changes in control; (r) the delivery of fairness opinions by Merrill
Lynch  in the  case of  WPLH, Morgan  Stanley in  the case  of IES,  and Salomon
Brothers in the case of IPC; (s)  the maintenance of adequate insurance and  (t)
the  absence of ownership of  each other's stock. In  addition, each of WPLH and
IES provides representations with respect to their respective shareowner  rights
plans not being triggered by the consummation of the Mergers and with respect to
the operations of their nuclear facilities.
 
CERTAIN COVENANTS
 
    Pursuant  to the  Merger Agreement,  each of WPLH,  IES and  IPC have agreed
that, during  the  period  from the  date  of  the Merger  Agreement  until  the
Effective  Time,  except as  permitted by  the  Merger Agreement  (including the
disclosure schedules thereto) or  the Stock Option  Agreements, or as  otherwise
consented  to  in writing  by the  other parties,  it will  (and will  cause its
Subsidiaries to), subject to certain  exceptions specified therein, among  other
things:  (a) carry on its business in  the ordinary course consistent with prior
practice; (b) not declare or pay any dividends on or make other distributions in
respect of  any  of  its  capital  stock,  other  than  to  such  party  or  its
wholly-owned  subsidiaries, dividends required  to be paid  on any IES Preferred
Stock (no shares of which are currently outstanding), Utilities Preferred Stock,
WP&L Preferred Stock or IPC Preferred Stock, and regular quarterly dividends  to
be  paid on  WPLH Common  Stock not  to exceed  in any  fiscal year  105% of the
dividends for the prior fiscal year, and regular quarterly dividends to be  paid
on  IES Common Stock and IPC Common Stock  not to exceed in any fiscal year 100%
of the dividends for the prior fiscal year; (c) not effect certain other changes
in its capitalization other  than redeeming any series  of IES Preferred  Stock,
Utilities  Preferred  Stock, WP&L  Preferred Stock  or  IPC Preferred  Stock, as
required by  their  respective terms,  or  in  connection with  a  refunding  of
preferred  stock at  a lower cost  of funds,  or if necessary  to facilitate the
transactions contemplated by the Merger Agreement; (d) not issue or encumber any
capital stock, rights,  warrants, options or  convertible or similar  securities
other than (i) issuances pursuant to the Stock Option Agreements, (ii) issuances
pursuant  to  the benefit  plans relating  to  certain WPLH  Subsidiaries; (iii)
intercompany issuances, (iv)  issuances in connection  with refunding  preferred
stock  with preferred stock or  debt at a lower cost  of funds, (v) issuances in
connection with  dividend  reinvestment plans  or  shareowner rights  plans,  as
applicable,  and (vi) up to 450,000 shares of IES Common Stock, 1,000,000 shares
of WPLH Common Stock  and 200,000 shares  of IPC Common Stock  to be issued  for
general  corporate purposes, including issuances in connection with acquisitions
and financings and issuances  pursuant to employee  benefit plans, stock  option
and  other incentive compensation plans and  directors' plans; (e) not amend its
articles  of  incorporation,  by-laws   or  regulations  or  similar   corporate
documents;  (f) not engage in material  acquisitions in excess of $10,000,000 in
the case  of each  of WPLH  and IES  or $5,000,000  in the  case of  IPC in  the
aggregate  over the amounts budgeted  or forecasted by each  such party; (g) not
enter into any written commitments for  the purchase of sulfur dioxide  emission
allowances  as provided for by the Clean Air Act Amendments of 1990 in excess of
an aggregate of $1,000,000 in the case of WPLH, $500,000 in the case of IES  and
$250,000  in the case of IPC; (h) not make any capital expenditures in excess of
$50,000,000 in the case of WPLH, $80,000,000 in the case of IES and  $16,000,000
in the case of IPC in the aggregate over the amounts budgeted by each such party
for  capital expenditures; (i) not sell, lease, encumber or otherwise dispose of
material assets in an aggregate amount equalling or exceeding $10,000,000 in the
case of each  of WPLH  and IES and  $2,000,000 in  the case of  IPC, other  than
planned  or ordinary course  of business dispositions  and encumbrances; (j) not
incur indebtedness (or
 
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<PAGE>
guarantees thereof),  other than  (i) short-term  indebtedness in  the  ordinary
course  of business consistent with  prior practice, (ii) long-term indebtedness
not aggregating more than  $40,000,000 in the case  of WPLH, $60,000,000 in  the
case  of IES and $20,000,000 in the case of IPC; (iii) arrangements between such
party and its Subsidiaries  or among its Subsidiaries,  (iv) in connection  with
the  refunding of  existing indebtedness  at a  lower cost  of funds,  or (v) in
connection with any permitted refunding of preferred stock; (k) not enter  into,
adopt  or amend or increase  the amount or accelerate  the payment or vesting of
any benefit  or  amount  payable  under, any  employee  benefit  plan  or  other
agreement,  commitment, arrangement, plan or policy, except for normal increases
in the ordinary course  of business consistent with  past practice that, in  the
aggregate,  do not  result in  a material  increase in  benefits or compensation
expense to such party or any of its Subsidiaries; (l) not engage in any activity
which would cause a change  in its status under the  1935 Act; (m) not  commence
construction  of  or  obligate  itself to  purchase  any  additional generating,
transmission or delivery capacity in an  amount in excess of $30,000,000 in  the
case of WPLH, $80,000,000 in the case of IES and $16,000,000 in the case of IPC,
other  than in the ordinary course of  business consistent with past practice or
pursuant to tariffs on file with the FERC or as budgeted or forecasted; (n)  not
make  any material change in their accounting  methods other than as required by
law or in accordance with generally accepted accounting principles; (o) not take
any action  to  prevent  Interstate  Energy from  accounting  for  the  business
combination  to be effected  by the Mergers  as a pooling  of interests; (p) not
take any action  that would  adversely affect  the status  of the  Mergers as  a
tax-free  transaction; (q) not enter into agreements with affiliates (other than
wholly-owned Subsidiaries) other  than on an  arm's-length basis; (r)  cooperate
with  the other parties, provide reasonable access  to its books and records and
notify the other parties  of any significant changes;  (s) use all  commercially
reasonable  efforts to obtain  certain third-party consents  to the Mergers; (t)
not take any action that would or  is reasonably likely to result in a  material
breach  of any provision of the Merger  Agreement or the Stock Option Agreements
or cause any of the representations and warranties therein to be untrue on or as
of the Closing Date; (u)  not take any action that  is likely to jeopardize  the
qualification  of  WP&L's,  Utilities'  or IPC's  outstanding  revenue  bonds as
tax-exempt industrial revenue bonds; (v) create a joint transition steering team
to examine  alternatives to  effect the  integration of  the parties  after  the
Effective  Time;  (w) take,  and cause  their Subsidiaries  to take,  only those
actions that are  required, permitted  or contemplated by  the Merger  Agreement
from  the date thereof to the Effective  Time; (x) refrain from taking specified
actions relating  to certain  tax  matters; (y)  not  discharge or  satisfy  any
claims, liabilities or obligations, other than discharges in the ordinary course
of  business or in accordance with their  terms, of liabilities reflected in the
most recent consolidated financial statements;  (z) not, except in the  ordinary
course  of  business, change  the status  of  any of  its material  contracts or
agreements or waive or release or assign any material rights or claims; and (aa)
maintain adequate insurance and use reasonable efforts to maintain all  existing
governmental permits.
 
    The  parties also agreed in the Merger  Agreement that, prior to the Closing
Date, (a) WPLH  and IPC  will take  all actions  necessary so  the WPLH  Charter
Amendments become effective no later than the Effective Time and the IPC Charter
Amendment  becomes effective prior to the Effective Time; and (b) IES will amend
its rights agreement to terminate no later than the Effective Time.
 
    The Merger Agreement provides that if  the parties are unable to obtain  the
necessary statutory approvals and other third-party consents which are necessary
to  effect  the  strategic  combination  of  WPLH,  IES  and  IPC  in  the  form
contemplated by  the  Merger  Agreement,  and the  adoption  of  an  alternative
structure  (that otherwise  substantially preserves  for WPLH,  IES and  IPC the
economic benefits  of  the  Mergers)  would  result  in  such  conditions  being
satisfied or waived, then the parties shall use their respective best efforts to
effect  a business  combination among themselves  by means of  a mutually agreed
upon structure other than the Mergers that so preserves such benefits.
 
NO SOLICITATION OF TRANSACTIONS
 
    The Merger Agreement  provides that  no party  thereto will,  and each  such
party  will cause its Subsidiaries  not to, and each  such party will not permit
any of  its officers,  directors,  employees, accountants,  counsel,  investment
bankers,   financial   advisors   and   other   representatives   (collectively,
 
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"Representatives") to, and each  such party will use  its best efforts to  cause
such  persons not to, directly or indirectly: initiate, solicit or encourage, or
take any  action  to  facilitate the  making  of  any offer  or  proposal  which
constitutes  or  is  reasonably  likely to  lead  to,  any  Business Combination
Proposal (as  defined herein),  or,  in the  event  of an  unsolicited  Business
Combination  Proposal, except to  the extent required  by their fiduciary duties
under applicable law  if so  advised in a  written opinion  of outside  counsel,
engage in negotiations or provide any information or data to any person relating
to  any  Business Combination  Proposal.  As used  above,  "Business Combination
Proposal"  means  any  tender  or   exchange  offer,  proposal  for  a   merger,
consolidation  or other business  combination involving any  party to the Merger
Agreement or any of its material Subsidiaries, or any proposal or offer (in each
case, whether or not in writing and whether or not delivered to the  shareowners
of  a  party generally)  to acquire  in  any manner,  directly or  indirectly, a
substantial equity interest  in or a  substantial portion of  the assets of  any
party  to the Merger Agreement, or any  of its material Subsidiaries, other than
pursuant to the transactions contemplated by the Merger Agreement.
 
INTERSTATE ENERGY BOARD OF DIRECTORS
 
    The Merger Agreement provides that the WPLH Board, the IES Board and the IPC
Board will take such action as may be necessary to cause the number of directors
comprising the full Interstate Energy Board at the Effective Time to be  fifteen
persons. The directors will be divided into three classes (hereafter referred to
as  "Class  I," "Class  II" and  "Class III")  of five  directors each.  Class I
directors will be appointed for a term  expiring at the first annual meeting  of
the  shareowners of  Interstate Energy  following the  Effective Time,  Class II
directors will be appointed for a term expiring at the second annual meeting  of
shareowners  of Interstate  Energy following the  Effective Time,  and Class III
directors will be appointed for a term  expiring at the third annual meeting  of
shareowners  of Interstate Energy following the Effective Time, and in each case
until their respective successors have been duly elected and qualified. Prior to
the Effective Time, WPLH and IES will each designate two directors and IPC  will
designate  one director for each  of Classes I and  II. Class III directors will
consist of Mr. Liu,  Mr. Davis and  Mr. Stoppelmoor, as  well as two  additional
directors,  one of whom will be designated by  each of WPLH and IES prior to the
Effective Time.  Directors designated  by  WPLH, IES  and IPC  (including  their
successors)  are hereinafter sometimes referred to  as the "WPLH Directors," the
"IES Directors" and the  "IPC Directors," respectively. To  date, WPLH, IES  and
IPC  have not determined who, in addition to Messrs. Liu, Davis and Stoppelmoor,
will be designated to serve on  the Interstate Energy Board after the  Effective
Time.  If after  their selection and  prior to  the Effective Time,  any of such
designees shall decline or  be unable to serve,  the party that designated  such
person shall designate another person to serve in such person's stead.
 
    The  Merger Agreement  also provides that  for a period  commencing with the
Effective Time and  expiring on  the date  of the  third annual  meeting of  the
shareowners  of the Company following the Effective  Time, the WPLH, IES and IPC
Directors (each as a separate group) will be entitled to nominate those  persons
who  will be eligible to be appointed, elected or reelected as WPLH, IES and IPC
Directors, respectively. The WPLH  Board, the IES Board  and the IPC Board  will
also  take such action  as may be  necessary to cause  the Nominating, Audit and
Compensation Committees of the Interstate Energy Board at the Effective Time  to
consist  proportionately (to the extent  reasonably practicable) of designees of
each of WPLH, IES and IPC.
 
    The Merger  Agreement further  provides  that for  a  period of  five  years
following  the Effective Date, no person who is an executive officer or employee
of Interstate Energy or any of its  subsidiaries will be eligible to serve as  a
director  of Interstate  Energy except for  Messrs. Liu,  Davis and Stoppelmoor.
However, if  Mr.  Davis  is not  then  serving  as Chief  Executive  Officer  of
Interstate Energy, the person serving in such capacity will be eligible to serve
as a director of Interstate Energy.
 
INDEMNIFICATION
 
    The  Merger Agreement provides that, to the  extent, if any, not provided by
an existing right  of indemnification  or other  agreement or  policy, from  and
after  the  Effective  Time,  Interstate  Energy  will,  to  the  fullest extent
permitted by applicable law, indemnify, defend and hold harmless each person who
was at, or who had been at any time prior to, the date of the Merger  Agreement,
or  who becomes prior to the Effective Time, an officer, director or employee of
any of the parties thereto or
 
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any  subsidiary  (the  "Indemnified  Parties")  against  all  losses,   expenses
(including   reasonable  attorney's  fees  and  expenses),  claims,  damages  or
liabilities or, subject to the proviso of the next succeeding sentence,  amounts
paid in settlement, arising out of actions or omissions occurring at or prior to
the  Effective Time (and whether  asserted or claimed prior  to, at or after the
Effective Time) that are, in  whole or in part, based  on or arising out of  the
fact  that such person is or was a  director, officer or employee of such party,
and all such indemnified liabilities to the  extent they are based on arise  out
of  or pertain to the transactions contemplated  by the Merger Agreement. In the
event of any  such loss,  expense, claim, damage  or liability  (whether or  not
arising  before  the  Effective  Time),  (i)  Interstate  Energy  will  pay  the
reasonable fees and  expenses of  counsel selected by  the Indemnified  Parties,
which counsel will be reasonably satisfactory to Interstate Energy and otherwise
advance  to  such Indemnified  Party  upon request  reimbursement  of documented
expenses reasonably  incurred,  (ii) Interstate  Energy  will cooperate  in  the
defense  of any such matter and (iii) any determination required to be made with
respect to whether an  Indemnified Party's conduct  complies with the  standards
set  forth  under  Wisconsin  law  and  the  Interstate  Energy  Charter  or the
Interstate Energy Bylaws will be made by independent counsel mutually acceptable
to  Interstate  Energy  and  the  Indemnified  Party;  PROVIDED,  HOWEVER,  that
Interstate  Energy will  not be liable  for any settlement  effected without its
written consent (which consent shall  not be unreasonably withheld). The  Merger
Agreement  further provides that  the Indemnified Parties as  a group may retain
only one law firm  with respect to  each unrelated matter  except to the  extent
there  is, in the opinion  of counsel to an  Indemnified Party, under applicable
standards of professional conduct, a  conflict on any significant issue  between
positions  of  such  Indemnified  Party  and  any  other  Indemnified  Party  or
Indemnified Parties.
 
    In addition, the Merger  Agreement requires that for  a period of six  years
after  the  Effective Time,  Interstate Energy  will cause  to be  maintained in
effect policies of  directors' and officers'  liability insurance maintained  by
WPLH,  IES and  IPC for the  benefit of those  persons who were  covered by such
policies as of the date of the Merger Agreement on terms no less favorable  than
the  terms of such insurance coverage,  PROVIDED that Interstate Energy will not
be required to  expend in any  year an amount  in excess of  150% of the  annual
aggregate  premiums currently paid by WPLH, IES  and IPC for such insurance and,
PROVIDED FURTHER that if the annual  premiums of such insurance coverage  exceed
such  amount, Interstate Energy shall  be obligated to obtain  a policy with the
best coverage available,  in the  reasonable judgment of  the Interstate  Energy
Board, for a cost not exceeding such amount. Also, the Merger Agreement provides
that  to the fullest extent  allowed by law, from  and after the Effective Time,
all rights  to  indemnification existing  in  favor of  the  employees,  agents,
directors  and  officers  of  WPLH,  IES  and  Interstate  and  their respective
subsidiaries with respect  to their activities  as such prior  to the  Effective
Time,  as provided in  their respective articles of  incorporation and bylaws in
effect on the date of the Merger Agreement or otherwise in effect on the date of
the Merger Agreement will  survive the Mergers and  will continue in full  force
and effect for a period of not less than six years from the Effective Time.
 
CONDITIONS TO EACH PARTY'S OBLIGATION TO EFFECT THE MERGERS
 
    The  respective obligations of WPLH,  IES and IPC to  effect the Mergers are
subject to the following  conditions: (a) the approval  of the Merger  Agreement
and  the transactions contemplated  thereby by the shareowners  of WPLH, IES and
IPC, the approval of the IPC Charter Amendment by the shareowners of IPC and the
approval of  the WPLH  Charter Amendments  by the  shareowners of  WPLH; (b)  no
temporary  restraining order, preliminary or permanent injunction or other order
by any federal or state court shall  be in effect that prevents consummation  of
the Mergers; (c) the Joint Registration Statement shall have become effective in
accordance  with  the provisions  of the  Securities  Act and  shall not  be the
subject of  a  stop order  suspending  such  effectiveness; (d)  the  shares  of
Interstate Energy Common Stock issuable in connection with the Merger shall have
been  authorized for listing on the NYSE,  upon official notice of issuance; (e)
the receipt of  all material  governmental authorizations,  consents, orders  or
approvals  which do  not impose  terms or  conditions which  could reasonably be
expected to have a material adverse effect on Interstate Energy; (f) the receipt
by each  of WPLH,  IES and  IPC of  letters from  their independent  accountants
stating that the business combination to be effected by the Mergers will qualify
as  a  pooling  of  interests transaction  under  generally  accepted accounting
principles  and  applicable  SEC  regulations;   (g)  the  performance  in   all
 
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material  respects  of  all obligations  of  the  other parties  required  to be
performed under the Merger  Agreement and the Stock  Option Agreements; (h)  the
accuracy of the representations and warranties of the other parties set forth in
the  Merger Agreement  as of  the date  of the  Merger Agreement  and as  of the
Closing Date (except as would not reasonably  be likely to result in a  material
adverse  effect); (i) WPLH,  IES and IPC  having received officers' certificates
from each  other  stating  that  certain conditions  set  forth  in  the  Merger
Agreement  have been satisfied; (j) there having been no material adverse effect
on the business, assets, financial condition, results of operations or prospects
of the other parties and their subsidiaries taken as a whole; (k) the receipt of
tax opinions from counsel to each party  to the effect that the Mergers will  be
treated  as tax-free reorganizations  under Section 368(a) of  the Code; (l) the
receipt by the other parties of  certain material third-party consents; and  (m)
the  receipt by  Interstate Energy of  letter agreements relating  to trading in
securities of  WPLH, IES  and IPC  (substantially  in the  form attached  as  an
exhibit  to the Merger Agreement), duly executed  by each affiliate of the other
party.
 
    In addition, the Merger Agreement provides  that it shall be a condition  to
the  obligations of WPLH  to hold the  WPLH Meeting that  the opinion of Merrill
Lynch attached hereto as Annex  L shall not have been  withdrawn, it shall be  a
condition  to the obligation of IES to hold  the IES Meeting that the opinion of
Morgan Stanley attached hereto as Annex M shall not have been withdrawn, and  it
shall  be a condition to the obligation of  IPC to hold the IPC Meeting that the
opinion of  Salomon Brothers  attached hereto  as Annex  N shall  not have  been
withdrawn.
 
    At  any  time  prior to  the  Effective  Time, to  the  extent  permitted by
applicable law, the conditions to the obligations of each of WPLH, IES or IPC to
consummate the Mergers may be waived in writing by such party. Any determination
to waive a condition would depend  upon the facts and circumstances existing  at
the  time of  such waiver  and would  be made  by the  waiving party's  Board of
Directors, exercising its  fiduciary duties  to its  shareowners. No  shareowner
approval will be required or sought for any such waiver; a shareowner's approval
of  the Merger Agreement constitutes approval of  such waivers as may be granted
by the Board of Directors in its discretion. See " -- Amendment and Waiver."
 
BENEFIT PLANS
 
    Except for  the  benefit plans  referred  to in  the  immediately  following
paragraph,  each of the benefit plans  of WPLH, IES and IPC  in effect as of the
date of  the Merger  Agreement will  be continued  for the  employees or  former
employees  of WPLH, IES and IPC and any of their Subsidiaries who are covered by
such plans  immediately  prior to  the  Closing Date,  until  Interstate  Energy
otherwise  determines after  the Effective Time  (subject to  any reserved right
contained in  any  such  benefit  plan to  amend,  modify,  suspend,  revoke  or
terminate  such  plan). To  the extent  certain  of such  benefit plans  are not
continued, Interstate Energy or its subsidiaries have agreed to provide, for  at
least  one  year  following  the  Effective Time,  benefits  which  are  no less
favorable in the aggregate that the  benefits provided under the affected  WPLH,
IES  or IPC benefit plans.  Each participant in a WPLH,  IES or IPC benefit plan
shall receive  credit for  purposes of  eligibility to  receive benefits  under,
vesting  and benefit accrual under an Interstate Energy benefit plan for service
credited for the corresponding purpose
under such benefit plan. Any employee first hired after the Closing Date will be
eligible to participate in  any benefit plan maintained,  or contributed to,  by
the  subsidiary, division  or operation employing  such person, so  long as such
person meets the eligibility requirements of such plan.
 
    Prior to the Effective Time, (i) each outstanding option to purchase  shares
of  IES Common Stock under an IES stock  plan (each an "IES Stock Option") along
with any tandem stock appreciation right,  will constitute an option to  acquire
on  the same terms and conditions as  were applicable under such option (subject
to the  adjustments necessary  to give  effect  to the  IES Merger),  shares  of
Interstate  Energy Common Stock based on the same number of shares of Interstate
Energy Common Stock  as the  holder of  such IES  Stock Option  would have  been
entitled  to receive pursuant to  the IES Merger had  such holder exercised such
option in full immediately prior to the Effective Time and (ii) each
 
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other outstanding award under an IES stock plan (each an "IES Stock Award") will
constitute  an award based upon  the same number of  shares of Interstate Energy
Common Stock as the holder of such  IES Stock Award would have been entitled  to
receive  pursuant to the IES Merger had  such holder been the owner, immediately
before the Effective Time of  the shares of IES Common  Stock on which such  IES
Stock Award is based, and otherwise on the same terms and conditions as governed
such IES Stock Award immediately before the Effective Time.
 
TERMINATION
 
    The  Merger Agreement  may be  terminated at any  time prior  to the Closing
Date, whether before or after approval by the shareowners of WPLH, IES and  IPC:
(a) by mutual written consent of WPLH, IES and IPC; (b) by any party thereto, by
written  notice  to the  other parties,  if  the Effective  Time shall  not have
occurred on or before May 10, 1997 (which date shall be extended to May 10, 1998
if the required statutory approvals and  consents have not been obtained by  May
10,  1997, but all other conditions to Closing  shall be, or shall be capable of
being fulfilled); PROVIDED,  HOWEVER, that  such right to  terminate the  Merger
Agreement  will  not be  available to  any  party whose  failure to  fulfill any
obligation under the Merger Agreement has been the cause of, or resulted in, the
failure of the Effective Time to occur on or before that date; (c) by any  party
thereto  if any  required shareowner  approval was not  obtained at  a duly held
meeting of shareowners or at any adjournment thereof; (d) by any party  thereto,
if  any state or  federal law, order,  rule or regulation  is adopted or issued,
which has  the effect  of prohibiting  the Mergers,  or any  court of  competent
jurisdiction  in the U.S. or  any state shall have  issued an order, judgment or
decree permanently restraining, enjoining or otherwise prohibiting the  Mergers,
and  such order, judgment  or decree shall have  become final and nonappealable;
(e) by WPLH, IES or IPC upon two days' prior notice to the other parties, if, as
a result of a tender offer by a  person other than the other parties, or any  of
their  affiliates, or any written offer or  proposal with respect to a merger of
such party, sale of a material portion of such party's assets or other  business
combination  involving such party  (each, a "Business  Combination") by a person
other than the other parties, or any of their affiliates, the Board of Directors
of such party  determines in  good faith  that its  fiduciary obligations  under
applicable law require that such tender offer or other written offer or proposal
be  accepted; PROVIDED, HOWEVER, that  (i) the Board of  Directors of such party
has been advised in  writing by outside counsel  that notwithstanding a  binding
commitment  to consummate  an agreement  of the  nature of  the Merger Agreement
entered into in  the proper exercise  of their applicable  fiduciary duties  and
notwithstanding  all concessions which may be offered by the other parties, such
fiduciary duties would also require the directors to reconsider such  commitment
as  a result of such  tender offer or other written  offer or proposal; and (ii)
prior to any such termination, such party shall, and shall cause its  respective
financial  and legal advisors to, negotiate with  the other parties to make such
adjustments in the terms and conditions of the Merger Agreement as would  enable
such  party  to  proceed  with the  transactions  contemplated  thereby  on such
adjusted terms, or  (f) by either  WPLH, IES or  IPC, by written  notice to  the
other parties, if (i) there exist breaches of the representations and warranties
on  the part of either of the other  parties made in the Merger Agreement or the
Stock Option Agreements as of the  date thereof which breaches, individually  or
in  the aggregate, would or  would be reasonably likely  to result in a material
adverse  effect  on  the  business,  assets,  financial  condition,  results  of
operations  or prospects  of such  other party and  its subsidiaries  taken as a
whole, and  such breaches  shall not  have been  remedied within  20 days  after
receipt by the breaching party of notice in writing from the non-breaching party
or  parties, specifying the nature of such  breaches and requesting that they be
remedied;  (ii)  either   of  the  other   parties  (and/or  their   appropriate
Subsidiaries)  has  not  performed and  complied  in all  respects  with certain
agreements and covenants relating to the absence of changes in capitalization or
issuance of securities  or has  failed to perform  and comply,  in all  material
respects,  with its other agreements and covenants under the Merger Agreement or
under the Stock Option Agreements, and such failure to perform or comply has not
been remedied within 20 days after receipt  by the breaching party of notice  in
writing  from the non-breaching party, specifying the nature of such failure and
requesting that it be remedied, or (iii) the Board of Directors of either of the
other parties  or any  committee thereof  (A) shall  withdraw or  modify in  any
manner  adverse  to such  party  its approval  or  recommendation of  the Merger
Agreement
 
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or the Mergers, (B) shall fail to reaffirm such approval or recommendation  upon
such  party's request, (C) shall approve  or recommend any acquisition of either
of the other parties or a material  portion of their assets or any tender  offer
for  either of the  other parties' common stock,  in each case  by a party other
than such party or any of its affiliates or (D) shall resolve to take any of the
actions specified in clause (A), (B), or (C).
 
    In the event of termination of the  Merger Agreement by either WPLH, IES  or
IPC  as provided above, there shall be no liability or obligation on the part of
WPLH, IES or  IPC or  their respective  officers or  directors thereunder  other
than:  to hold  in strict  confidence all  documents furnished  to the  other in
accordance with the Confidentiality Agreement, dated September 19, 1995, as  may
be  amended from time to time  (the "Confidentiality Agreement"); to pay certain
fees and  expenses  pursuant  to  certain specified  provisions  of  the  Merger
Agreement  described below under "-- Termination Fees" and "-- Expenses"; and to
comply with certain other specified provisions of the Merger Agreement.
 
    The Merger Agreement does not provide for any modification in the Ratios due
to changes in the  operating results, financial condition  or trading prices  of
the  WPLH Common Stock, IES Common Stock or IPC Common Stock between the time of
the execution of the Merger Agreement  and the consummation of the  transactions
contemplated thereby.
 
TERMINATION FEES
 
    The  Merger Agreement provides that if the Merger Agreement is terminated at
such time as  it is  terminable by  WPLH, IES  or IPC  (but not  all three)  for
breaches  of any representations or warranties contained in the Merger Agreement
as of the date thereof, or of  agreements and covenants contained in the  Merger
Agreement  or the  Stock Option  Agreements, pursuant  to the  provisions of the
Merger Agreement described in clauses (f)(i) and (f)(ii) under "--  Termination"
above,  then if such breach is not willful, each non-breaching party is entitled
to reimbursement  of  its  documented  out-of-pocket  expenses,  not  to  exceed
$5,000,000  per each non-breaching party. In the  event of a willful breach, the
non-breaching party or parties  will be entitled to  its or their  out-of-pocket
expenses and fees (which shall not be limited to $5,000,000) and any remedies it
or  they may have at law or in equity,  and provided that if, at the time of the
breaching  party's  or  parties'  willful  breach,  there  shall  have  been   a
third-party  tender offer or  proposal for a Business  Combination which has not
been rejected by the breaching party or parties or withdrawn by the third party,
and within two and one-half years of any termination by the non-breaching  party
or  parties, the breaching party or parties  become a subsidiary of such offeror
or of  an  affiliate  of such  offeror  or  accept an  offer  to  consummate  or
consummates  a Business Combination  with such third  party, then such breaching
party or parties, upon the closing of such Business Combination, will pay to the
non-breaching party or parties an additional aggregate fee equal to $25,000,000,
if WPLH or IES is the breaching  party, or $12,500,000, if IPC is the  breaching
party.
 
    The  Merger Agreement also requires payment  of an aggregate termination fee
of $25,000,000, if WPLH or IES is the Target Party (as hereinafter defined),  or
$12,500,000,  if  IPC  is  the  Target  Party,  together  with  reimbursement of
out-of-pocket expenses, by one party (the  "Target Party") to the other  parties
in  the following circumstances: (1) the Merger Agreement is terminated (x) as a
result of the acceptance by  the Target Party of  a third-party tender offer  or
proposal  for a Business Combination, (y) following a failure of the shareowners
of the Target Party to grant their approval to the Mergers or (z) as a result of
the Target Party's material failure to convene a shareowner meeting,  distribute
proxy  materials  and,  subject to  its  Board of  Directors'  fiduciary duties,
recommend the Mergers to its shareowners; (2) at the time of such termination or
prior to the meeting  of such party's shareowners  there has been a  third-party
tender  offer or proposal for  a Business Combination which  shall not have been
rejected by the Target Party  or withdrawn by such  third party; and (3)  within
two  and one-half years of  any such termination described  in clause (1) above,
the Target Party accepts an
 
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offer to consummate or consummates a Business Combination with such third party.
The applicable termination  fee and  out-of-pocket expenses referred  to in  the
previous  sentence  will be  paid at  the closing  of such  third-party Business
Combination.
 
    In addition to the  foregoing, if the Merger  Agreement is terminated  under
circumstances  that give  rise to the  payment of the  termination fee discussed
above by the  Target Party  referred to  above and  within nine  months of  such
termination  one  of  the  non-terminating  parties  is  acquired  by  the  same
third-party offeror, the sole remaining party  will be entitled to (i) a  second
termination  fee of $25,000,000, if  WPLH or IES is  the second target party, or
$12,500,000 if IPC is the  second target party, on  the signing of a  definitive
agreement,  or if no such  agreement is signed at  the closing, relating to such
Business Combination,  and (ii)  payment of  any termination  fee paid  to  such
second  target party by  the original terminating party  (I.E., the first Target
Party) pursuant to the  termination of the Merger  Agreement. If only one  party
must  pay expenses,  or is entitled  to receive  a termination fee  as set forth
above, such  party  will  pay or  receive  one  hundred percent  (100%)  of  the
applicable  expenses or  fee. If  two parties  are required  to pay  expenses or
entitled to receive any such fee, each such party's percentage of such  expenses
or  fee will equal a fraction,  the numerator of which shall  be, in the case of
IES or IPC, the number of shares  of Interstate Energy Common Stock which  would
have  been issuable (on a fully diluted  basis) to such party's shareowners, or,
in the case of WPLH, the number of shares of Interstate Energy Common Stock  (on
a fully diluted basis) that would have been retained by its shareowners, had the
Effective  Time occurred at the time the Merger Agreement is terminated, and the
denominator of which will be the aggregate number of shares of Interstate Energy
Common Stock that would have been issuable to or retained by (in either case  on
a  fully  diluted basis)  the shareowners  of  the two  parties required  to pay
expenses or entitled to receive such fee had the Effective Time occurred at  the
time the Merger Agreement is terminated.
 
    In   the  event   that  the   Merger  Agreement   becomes  terminable  under
circumstances in which a termination fee could be payable by one or more parties
(the "Payor" or "Payors") pursuant to the immediately preceding paragraph,  such
event  will also constitute a "Trigger  Event" under the Stock Option Agreements
pursuant to which the Payors issued Options to the other party or parties, so as
to entitle the other party or parties  to require the Payors to repurchase  such
Option  or the Option Shares (as defined herein) issued upon exercise thereof or
to make a Trigger Payment (as  defined herein). The termination fees payable  by
WPLH,  IES and/or IPC  under the foregoing provisions  plus the aggregate amount
which could be payable by WPLH, IES and/or IPC under the Stock Option Agreements
may not exceed $40,000,000  (for WPLH or  IES) or $20,000,000  (for IPC) in  the
aggregate. See "The Stock Option Agreements."
 
    The  Merger Agreement further provides  that all termination fees constitute
liquidated damages and not a  penalty and, if one party  should fail to pay  any
termination  fee due, the  defaulting party shall  pay the cost  and expenses in
connection with any action taken to  collect payment, together with interest  on
the amount of any unpaid termination fee.
 
EXPENSES
 
    Except  as set  forth above, all  costs and expenses  incurred in connection
with the Merger  Agreement and  the transactions contemplated  thereby shall  be
paid by the party incurring such expense, except that those expenses incurred in
connection with the printing and filing of this Joint Proxy Statement/Prospectus
shall be shared 43% by WPLH, 43% by IES and 14% by IPC.
 
AMENDMENT AND WAIVER
 
    The Merger Agreement may be amended by the directors of the parties thereto,
at any time before or after approval thereof by the shareowners of WPLH, IES and
IPC  and prior to the Effective Time, but after such approvals no such amendment
shall alter  or  change the  amount  or kind  of  shares, rights  or  manner  of
conversion of such shares, alter or change any of the terms or conditions of the
Merger  Agreement  if  any  of  the alterations  or  changes,  alone  or  in the
aggregate, would materially adversely affect the rights of holders of WPLH,  IES
or  IPC  Common Stock,  or alter  or change  any term  of the  WPLH, IES  or IPC
Charters as  approved  by  the shareowners  of  WPLH,  IES or  IPC,  except  for
 
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alterations  or changes that could otherwise be adopted by the Interstate Energy
Board without the further  approval of such shareowners  (such as to delete  the
name  and  address  of  a  former registered  agent  or  office,  to  change the
registered agent or office or to  make certain limited changes in the  corporate
name).  The  parties  to  the  Merger Agreement  may  extend  the  time  for the
performance of  any  of the  obligations  or other  acts  of the  other  parties
thereto,  waive any inaccuracies in the representations and warranties contained
therein or in any document delivered pursuant thereto, and waive compliance with
any of the  agreements or conditions  contained in the  Merger Agreement to  the
extent permitted by law.
 
STANDSTILL PROVISIONS
 
    Pursuant  to  the Confidentiality  Agreement, WPLH,  IES  and IPC  have each
agreed (other  than as  contemplated in  the Merger  Agreement or  Stock  Option
Agreements),  that  they will  not,  for a  period of  two  years from  the date
thereof, (i) acquire or agree to acquire any securities of either or both of the
other parties  or any  warrant or  option for  such securities  or any  security
convertible  into such securities;  (ii) make or  in any way  participate in any
solicitation of proxies to vote, or seek to advise or influence any person  with
respect  to the voting  of, securities of  either or both  of the other parties;
(iii) otherwise  act to  seek  control or  influence  the management,  Board  of
Directors  or policies of either or both of  the other parties; or (iv) make any
public request to waive any provision of the Confidentiality Agreement to permit
such party to take any action prohibited above.
 
                          THE STOCK OPTION AGREEMENTS
 
    The following  is  a  brief  summary  of  the  terms  of  the  Stock  Option
Agreements,  copies of which are  attached as Annexes B  through G and which are
incorporated herein by reference. Such summary  is qualified in its entirety  by
reference  to  the  Stock Option  Agreements.  The Stock  Option  Agreements are
intended to increase  the likelihood  that the  Mergers will  be consummated  in
accordance with the terms of the Merger Agreement. Consequently, certain aspects
of  the Stock Option Agreements may have  the effect of discouraging persons who
might now or prior  to the Effective  Time be interested in  acquiring all or  a
significant  interest in,  or otherwise  effecting a  Business Combination with,
WPLH, IES or IPC from considering or proposing such a transaction, even if  such
persons  were prepared to offer to pay consideration to shareowners of WPLH, IES
or IPC,  as the  case  may be,  which had  a  higher value  than the  shares  of
Interstate  Energy Common Stock  to be received  per share of  IES or IPC Common
Stock or to be  retained by holders of  WPLH Common Stock, as  the case may  be,
pursuant to the Merger Agreement.
 
GENERAL
 
    Concurrently  with the Merger Agreement, WPLH,  IES and IPC entered into the
Stock  Option  Agreements.  As  holders  of  Options  thereunder  (the   "Option
Holders"),  WPLH, IES  and IPC have  the right, under  certain circumstances, to
purchase, up to  (i) with  respect to  the Options  granted by  WPLH (the  "WPLH
Options"),  6,123,944  shares of  WPLH Common  Stock; (ii)  with respect  to the
Options granted by IES (the "IES Options), up to 5,861,115 shares of IES  Common
Stock; and (iii) with respect to the Options granted by IPC (the "IPC Options"),
up  to 1,903,293 shares of IPC Common  Stock (shares of common stock purchasable
pursuant to  the  WPLH  Options,  the  IES  Options  and  the  IPC  Options  are
collectively referred to as the "Option Shares") at an exercise price of $30.675
per share for the WPLH Common Stock, $26.7125 per share for the IES Common Stock
and  $28.9375 per share for the IPC Common Stock, such prices being equal to the
average of the daily closing sale prices for such shares on the NYSE during  the
ten  NYSE trading days prior to the fifth NYSE trading day preceding the date of
the Merger Agreement.
 
    The Options may be exercised  by an Option Holder, in  whole or in part,  at
any  time or from time to time  after the Merger Agreement becomes terminable by
such Option Holder under circumstances which could entitle such Option Holder to
termination fees from  the issuer  of the Options  (the "Option  Grantor") as  a
result  of  a Trigger  Event  (as defined  in  the Stock  Option  Agreements and
described above under "The Merger Agreement -- Termination Fees"), regardless of
whether the
 
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Merger Agreement is actually terminated or whether there occurs a closing of any
Business Combination. If only one Option Holder becomes entitled to exercise its
Option as it relates to a specific  Option Grantor, the Option will be for  100%
of  the shares subject thereto. If more  than one Option Holder becomes entitled
to exercise its Option with respect to a specific Option Grantor, the percentage
of the number of  shares of the  Option Grantor's common  stock that the  Option
Holder  may purchase upon exercise  of the Option shall  be equal to a fraction,
the numerator of which will be the number of shares of Interstate Energy  Common
Stock  (on a fully diluted  basis) that would have  been acquired or retained by
the Option Holder's shareowners had the  effective time of the Mergers  occurred
as  of the date on which the exercise notice under the Stock Option Agreement is
delivered or the date  on which demand  for a Trigger Payment  is given, as  the
case may be, and the denominator of which will be the aggregate number of shares
of  Interstate Energy Common Stock that would  have been issuable to or retained
by (in either  case on a  fully diluted basis)  the shareowners of  both of  the
Option  Holders entitled to exercise their  respective Options had the effective
time of the  Mergers occurred as  of the date  on which the  exercise notice  is
delivered  or the date  on which demand for  a Trigger Payment  is given, as the
case may be. The exercise price under  the Stock Option Agreements may be  paid,
at the Option Holder's election, either in cash or shares of the common stock of
the Option Holder.
 
    The  Options will terminate upon the earlier of (i) the Effective Time, (ii)
the termination of  the Merger  Agreement pursuant to  its terms  (other than  a
termination  under  circumstances which  would constitute  a Trigger  Event), or
(iii) 180 days following any termination of the Merger Agreement upon or  during
the  continuance of a  Trigger Event (or,  if at the  expiration of such 180-day
period the Option  cannot be  exercised by  reason of  any applicable  judgment,
decree,  order, law  or regulation, ten  business days after  such impediment to
exercise shall have been removed or shall  have become final and not subject  to
appeal, but in no event under this clause (iii) later than May 10, 1998).
 
    Notwithstanding  the foregoing, no Option may be exercised (a) if the Option
Holder is  in  material  breach  of  any  of  its  material  representations  or
warranties,  or  in  material  breach  of any  of  its  covenants  or agreements
contained in the applicable Stock Option  Agreement or in the Merger  Agreement,
or  (b) if  a Trigger  Payment has  been paid  pursuant to  the applicable Stock
Option Agreement or a demand therefor has been made and not withdrawn.
 
CERTAIN REPURCHASES AND OTHER PAYMENTS
 
    Under the terms of the Stock Option Agreements, at any time during which the
Option is exercisable (the "Repurchase Period"), the Option Holder has the right
to require the Option Grantor  to repurchase from the  Option Holder all or  any
portion  of the Option or, at any time prior to May 10, 1997 (PROVIDED that such
date shall be extended to  May 10, 1998 under  the circumstances where the  date
after  which any party may  terminate the Merger Agreement  has been extended to
May 10, 1998), all or any portion  of the Option Shares purchased by the  Option
Holder  pursuant  to the  exercise of  the  Option. The  amount that  the Option
Grantor will pay to the Option Holder to repurchase the Option is the difference
between the Market/Offer Price for shares  of the Option Grantor's common  stock
as  of the  date the Option  Holder gives notice  of its intent  to exercise its
rights (the "Notice Date") and the exercise price for the Option, multiplied  by
the  number of Option Shares purchasable pursuant  to the Option, or the portion
thereof to be so repurchased, but only if the Market/Offer Price is greater than
such exercise price. The amount that the  Option Grantor will pay to the  Option
Holder  to repurchase the Option Shares is the exercise price paid by the Option
Holder for the Option Shares plus the difference between the Market/Offer  Price
and the exercise price paid by the Option Holder for the Option Shares (but only
if  the Market/Offer Price  is greater than such  exercise price), multiplied by
the number of Option  Shares to be so  repurchased. The Stock Option  Agreements
define "Market/Offer Price" as the higher of (A) the price per share (the "Offer
Price")  offered as of the Notice Date  pursuant to any tender or exchange offer
or other Business Combination offer which was made prior to the Notice Date  and
not  terminated or withdrawn as of such date or (B) the Fair Market Value of the
Option Grantor's common stock  as of the  Notice Date (which  is defined in  the
Stock  Option Agreements as the average of the daily closing sale price for such
shares on the  NYSE during the  ten NYSE trading  days prior to  the fifth  NYSE
trading day preceding such date). The Offer Price
 
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<PAGE>
for  the repurchase  by the  Option Grantor  of Option  Shares purchased  by the
Option Holder pursuant  to the  Option is the  highest price  per share  offered
pursuant to a tender or exchange offer or other Business Combination offer which
was  made during  the Repurchase Period  prior to  the Notice Date.  At any time
prior to May  10, 1997 (which  date may be  extended to May  10, 1998 under  the
circumstances  described above), the  Option Holder may  also require the Option
Grantor to sell to the  Option Holder any shares  of the Option Holder's  common
stock  delivered by the Option Holder to  the issuer in payment for the exercise
price of the Option, at  the price attributed to  such shares for such  purchase
plus  interest at the rate of 8.75% PER  ANNUM (from the date of the delivery of
such shares through  the date  of such repurchase)  less any  dividends paid  or
declared  and payable thereon. In addition,  the Stock Option Agreements provide
that in the event during the Repurchase Period any regulatory approval or  order
required  for the issuance  of the Option  by the Option  Grantor thereof or the
acquisition of  such Option  by the  Option Holder  has not  been obtained,  the
Option  Holder  will be  entitled  to demand  an  amount in  cash  (the "Trigger
Payment") from the  Option Grantor.  The Trigger Payment  will be  equal to  the
product  of the number of  shares the Option Holder  would have been entitled to
receive upon exercise of  the Option if the  regulatory approvals or orders  had
been obtained and the difference between the Market/Offer Price determined as of
the  date notice  of demand for  the Trigger  Payment is given  and the exercise
price of the  Option, but  only if  the Market/Offer  Price is  higher than  the
exercise price. In the event the Trigger Payment is made, the Option Holder will
have no right to exercise the Option.
 
VOTING
 
    Each  party has agreed to  vote, until November 10,  2000, any shares of the
capital stock  of  the  other  party  acquired  pursuant  to  the  Stock  Option
Agreements  or  otherwise  beneficially  owned  by  such  party  on  each matter
submitted to a  vote of shareowners  of such  other party for  and against  such
matter in the same proportion as the vote of all other shareowners of such other
party is voted for and against such matters.
 
RESTRICTIONS ON TRANSFER
 
    The  Stock Option Agreements provide that,  until November 10, 2000, neither
party may sell, assign, pledge or otherwise dispose of or transfer the shares it
acquires pursuant to the Stock Option Agreements (collectively, the  "Restricted
Shares")  except  as  described  below. In  addition  to  the  repurchase rights
described above under "-- Certain Repurchases and Other Payments," subsequent to
the termination of the Merger Agreement, the parties have the right to have such
shares of the  other party or  parties registered under  the Securities Act  for
sale  in  a public  offering.  The Stock  Option  Agreements also  provide that,
following the  termination of  the  Merger Agreement,  any  party may  sell  any
Restricted  Shares of another party  then held by it in  response to a tender or
exchange offer approved or recommended, or  otherwise determined to be fair  and
in the best interests of the shareowners of the issuer of the Restricted Shares,
by a majority of the Board of Directors of the issuer of the Restricted Shares.
 
             AMENDMENTS TO WPLH RESTATED ARTICLES OF INCORPORATION
 
    THE  INFORMATION  CONTAINED IN  THIS  JOINT PROXY  STATEMENT/PROSPECTUS WITH
RESPECT TO  THE PROPOSED  AMENDMENTS TO  THE WPLH  CHARTER IS  QUALIFIED IN  ITS
ENTIRETY  BY REFERENCE TO THE TEXT OF  THE PROPOSED AMENDMENTS TO THE INTERSTATE
ENERGY CHARTER ATTACHED HERETO AS ANNEX O AND INCORPORATED HEREIN BY REFERENCE.
 
    Pursuant to the terms  of the Merger Agreement,  WPLH shareowners are  being
asked  to consider and approve each of  the WPLH Charter Amendments, which would
amend the WPLH  Charter to  (i) change  the name  of WPLH  to Interstate  Energy
Corporation  and  (ii)  increase  the  number of  shares  of  WPLH  Common Stock
authorized for issuance from 100,000,000 to 200,000,000. The WPLH Charter as  so
amended  will be the Interstate  Energy Charter at the  Effective Time and until
thereafter amended  in  accordance  with  the WBCL  and  the  Interstate  Energy
Charter.
 
                                      101
<PAGE>
    THE  WPLH  BOARD UNANIMOUSLY  RECOMMENDS  A VOTE  FOR  APPROVAL OF  THE WPLH
CHARTER AMENDMENTS.  Approval  of each  of  the  WPLH Charter  Amendments  is  a
condition  to consummation of the Mergers. If approved by WPLH shareowners, each
of the WPLH Charter Amendments will not become effective until immediately prior
to or concurrent with the Effective Time. If, after WPLH shareowner approval  of
each  of the WPLH Charter Amendments, the Mergers are not consummated, WPLH will
not file the WPLH Charter Amendments  with the Wisconsin Secretary of State  and
the WPLH Charter Amendments will therefore not become effective.
 
NAME CHANGE AMENDMENT
 
    Pursuant  to  the  Merger  Agreement,  WPLH agreed  to  change  its  name to
Interstate Energy Corporation. Each of WPLH,  IES and IPC believes that the  new
name  reflects the nature of the merged company as a multi-state utility holding
company. Changing WPLH's name does not  substantively or otherwise alter any  of
the rights of WPLH shareowners.
 
    The  affirmative vote of a majority of the  votes entitled to be cast by the
holders of the shares of WPLH Common  Stock represented at the WPLH Meeting  and
entitled to vote thereon is required for approval of the Name Change Amendment.
 
COMMON STOCK AMENDMENT
 
    As  of the WPLH Record Date, of  the 100,000,000 shares of WPLH Common Stock
presently  authorized,  30,795,260  shares  were  issued  and  outstanding,  and
21,138,992 shares of WPLH Common Stock were reserved for issuance for a specific
purpose,  as follows: 399,497  shares under the WPLH  DRIP, 386,763 shares under
the WP&L  Savings  Plan,  1,000,000  shares  under  the  WPLH  Long-Term  Equity
Incentive  Plan and 19,352,732 shares under  the Rights Agreement. An additional
6,123,944 shares (subject to adjustment)  are reserved for issuance pursuant  to
the  WPLH Options, but  such Options to  purchase shares granted  to IES and IPC
thereunder  will  terminate  at  the  Effective  Time.  See  "The  Stock  Option
Agreements."  If the Mergers are consummated, up to 42,798,875 additional shares
of WPLH Common Stock will  be issued to former holders  of IES Common Stock  and
IPC  Common Stock. Additional  shares of WPLH  Common Stock will  be issuable to
holders of  employee  stock  options  to purchase  IES  Common  Stock  that  are
outstanding at the Effective Time, and will be converted into options to acquire
shares of WPLH Common Stock, upon exercise of such options.
 
    The  additional 100,000,000  authorized shares  of Interstate  Energy Common
Stock may be issued for any proper corporate purpose approved by the  Interstate
Energy  Board.  Without  the  Common  Stock Amendment,  WPLH  would  not  have a
sufficient number of authorized shares to complete the Mergers. The availability
of additional authorized shares will also enable the Interstate Energy Board  to
act  with flexibility when and as the  need arises to issue additional shares in
the future without  the delays  necessitated by  having to  obtain a  shareowner
vote.  Among  the reasons  for issuing  additional shares  would be  to increase
Interstate Energy's capital through sales of Interstate Energy Common Stock,  to
engage in other types of capital transactions, to undertake acquisitions, and to
satisfy  contractual commitments, including pursuant  to employee stock options.
The WPLH Board has not  proposed the increase in  the amount of authorized  WPLH
Common  Stock  with  the intention  of  discouraging tender  offers  or takeover
attempts  of  Interstate  Energy.   However,  the  availability  of   additional
authorized  shares  for issuance  could render  more  difficult or  discourage a
merger, tender  offer, proxy  contest  or other  attempt  to obtain  control  of
Interstate  Energy, which may adversely affect  the ability of Interstate Energy
shareowners to obtain  a premium for  their shares of  Interstate Energy  Common
Stock and, accordingly, have a negative effect on the price of Interstate Energy
Common Stock.
 
    WPLH   management   regularly  reviews   a   range  of   possible  financing
transactions, including the issuance of WPLH Common Stock. Except for (i) shares
to be issued in connection with the Mergers and (ii) shares issued in connection
with the benefit plans mentioned above, WPLH has no present intention of issuing
or selling WPLH Common Stock for any purpose, but may do so if market and  other
conditions  should indicate that  such a course of  action were advisable. Under
the Merger Agreement, WPLH has agreed  (other than for issuances under the  WPLH
DRIP and the Rights
 
                                      102
<PAGE>
Agreement),  from the date of the Merger Agreement through the Effective Time or
earlier termination of the  Merger Agreement, to issue,  without the consent  of
IES  and IPC, no more than 1,000,000  additional shares of WPLH Common Stock for
general corporate purposes, including issuances in connection with  acquisitions
and  financings and pursuant  to employee benefit plans,  stock option and other
incentive compensation plans and director plans.
 
    If the Common Stock Amendment is approved, while the Interstate Energy Board
generally may  issue  such additional  authorized  shares of  Interstate  Energy
Common  Stock without further shareowner approval, such issuances will generally
require the approval of the SEC under  the 1935 Act as presently in effect.  See
"Regulatory Matters." In some instances, shareowner approval for the issuance of
additional  shares may be required by law or by the requirements of the NYSE, on
which the Interstate  Energy Common Stock  will be listed,  or the obtaining  of
such approvals may be otherwise necessary or desirable. Except in such cases, it
is  not  anticipated that  further shareowner  authorization will  be solicited.
Holders of WPLH Common Stock are not entitled to preemptive rights to  subscribe
for  or purchase any part of any new or additional issue of WPLH Common Stock or
securities convertible into WPLH Common Stock.
 
    The affirmative vote of a majority of  the votes entitled to be cast by  the
holders  of the shares of WPLH Common  Stock represented at the WPLH Meeting and
entitled to vote thereon is required for approval of the Common Stock Amendment.
 
             AMENDMENT TO IPC RESTATED CERTIFICATE OF INCORPORATION
 
    THE INFORMATION  CONTAINED IN  THIS  JOINT PROXY  STATEMENT/PROSPECTUS  WITH
RESPECT  TO  THE PROPOSED  AMENDMENT  TO THE  IPC  CHARTER IS  QUALIFIED  IN ITS
ENTIRETY BY REFERENCE TO THE TEXT OF  THE PROPOSED AMENDMENT TO THE IPC  CHARTER
ATTACHED HERETO AS ANNEX R AND INCORPORATED HEREIN BY REFERENCE.
 
    In  furtherance of  the Merger  Agreement and  the transactions contemplated
thereby, IPC  stockholders are  being  asked to  consider  and approve  the  IPC
Charter  Amendment, which would amend the IPC Charter to provide that each share
of IPC Preferred Stock  outstanding from time  to time will  be entitled to  one
vote,  voting together as one class with  the holders of IPC Common Stock except
as otherwise required by law or as specifically provided in the IPC Charter,  on
all matters to come before a vote of the IPC stockholders.
 
    THE  IPC BOARD UNANIMOUSLY RECOMMENDS A VOTE FOR APPROVAL OF THE IPC CHARTER
AMENDMENT. Approval of the IPC Charter Amendment is a condition to  consummation
of  the Mergers. If approved by the  IPC stockholders, the IPC Charter Amendment
will become  effective as  soon as  practicable following  the date  of the  IPC
Meeting.
 
    As  discussed above, the Mergers are designed to be tax-free reorganizations
under the  Code. It  is a  condition to  the Mergers  that each  of the  parties
receive  from its respective counsel  an opinion to the  effect that the Mergers
will be  treated for  federal income  tax purposes  as tax-free  reorganizations
under the Code.
 
    For  the IPC Direct Merger or the IPC Merger, as the case may be, to qualify
as a tax-free reorganization under applicable Code provisions, IPC  stockholders
must  exchange a "controlling" stock interest in IPC or New IPC, as the case may
be, for WPLH (or Interstate Energy  after the Mergers) voting stock. To  satisfy
this  "control" requirement,  the ultimate  acquiror of  IPC's stock (Interstate
Energy) must acquire at least 80% of  the total combined voting power of IPC  or
New  IPC, as the case may be, plus at least 80% of the total number of shares of
all other IPC or New IPC, as the case may be, stock classes. Because the  Merger
Agreement  contemplates that holders of IPC Preferred Stock or New IPC Preferred
Stock, as the case  may be, will not  participate in the IPC  Merger or the  IPC
Direct  Merger, as the  case may be, (I.E.,  the IPC Preferred  Stock or New IPC
Preferred Stock, as  the case may  be, will remain  outstanding), the  "control"
requirement  will be met  only if the  IPC Preferred Stock  or New IPC Preferred
Stock, as the case  may be, is  voting stock before the  Effective Time and  the
vote  constitutes less  than 20%  of the  total voting  stock. Granting  the IPC
Preferred
 
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<PAGE>
Stock one vote per share will enable the ultimate acquiror of IPC's Common Stock
(Interstate Energy) to acquire "control" because it will acquire at least 80% of
the total combined  voting power of  IPC, there  being no other  classes of  IPC
stock outstanding.
 
    As  of July  10, 1996,  IPC had outstanding  9,595,028 shares  of IPC Common
Stock and  an aggregate  of  761,381 shares  of  IPC Preferred  Stock.  Assuming
approval  of  the IPC  Charter  amendment by  the  IPC stockholders  at  the IPC
Meeting,  the  IPC   Preferred  Stock   would  represent,   in  the   aggregate,
approximately  7.35% of  the total  combined voting  power of  IPC, and  the IPC
Common Stock would represent approximately  92.65% of the total combined  voting
power of IPC. The exchange then of IPC Common Stock for Interstate Energy Common
Stock  in the IPC Merger  would constitute an exchange  of a "controlling" stock
interest within the  meaning of Section  368(a)(2)(E) of the  Code, and the  IPC
Merger  would  be  eligible  for tax-free  reorganization  treatment  under that
provision.
 
    Approval of the IPC Charter Amendment would result in dilution of the voting
power of the IPC Common Stock of approximately 7.35%.
 
    No other  aspects of  IPC's Charter  will  be affected  by the  IPC  Charter
Amendment  nor will the IPC Charter Amendment  result in any other change in the
relative rights, preferences and other terms of the IPC Preferred Stock.
 
    The affirmative vote of a majority of  the votes entitled to be cast by  the
holders  of  shares of  IPC Common  Stock is  required for  approval of  the IPC
Charter Amendment.
 
                 DESCRIPTION OF INTERSTATE ENERGY CAPITAL STOCK
GENERAL
 
    Pursuant to the Merger Agreement, no later than the Effective Time, the WPLH
Charter will  be amended  substantially in  the  manner set  forth in  Annex  O,
subject  to shareowner approval  of each of  the WPLH Charter  Amendments at the
WPLH Meeting, and, as so amended,  shall be the Interstate Energy Charter  until
thereafter  amended  in  accordance  with the  WBCL  and  the  Interstate Energy
Charter. See  "Amendments  to  WPLH Restated  Articles  of  Incorporation."  The
authorized  capital stock of  Interstate Energy, as of  the Effective Time, will
consist of 200,000,000 shares of Interstate Energy Common Stock. The description
of Interstate  Energy capital  stock set  forth herein  does not  purport to  be
complete  and is qualified in its entirety by reference to the Interstate Energy
Charter and the Interstate Energy Bylaws, copies of which are filed as  exhibits
to  the Joint Registration  Statement and are  incorporated hereby by reference,
the proposed amendments  to the WPLH  Charter, attached hereto  as Annex O,  and
applicable statutory or other law.
 
INTERSTATE ENERGY COMMON STOCK
 
    The  holders of Interstate  Energy Common Stock will  be entitled to receive
such dividends as  the Interstate Energy  Board may from  time to time  declare.
Except  as provided by  the WBCL as  described below, each  holder of Interstate
Energy Common  Stock will  be entitled  to one  vote per  share on  each  matter
submitted  to a  vote at  a meeting  of shareowners.  The holders  of Interstate
Energy Common Stock will not be entitled  to cumulate votes for the election  of
directors.  In  the  event of  any  liquidation,  dissolution or  winding  up of
Interstate Energy,  the  holders  of  Interstate Energy  Common  Stock  will  be
entitled  to receive the remainder,  if any, of the  assets of Interstate Energy
after the  discharge of  its liabilities.  Holders of  Interstate Energy  Common
Stock will not be entitled to preemptive rights to subscribe for or purchase any
part  of any  new or  additional issue of  stock or  securities convertible into
stock. The  Interstate  Energy Common  Stock  does not  contain  any  redemption
provisions or conversion rights.
 
    The shares of Interstate Energy Common Stock that will be issued pursuant to
the  Merger  Agreement, when  so issued,  will be  fully paid  and nonassessable
except as provided by  Section 180.0622(2)(b) of the  WBCL, which provides  that
shareowners will be personally liable up to the par value of the shares owned by
them  for all debts owing to employees of the Company for services performed for
the Company not exceeding 6  months service in any  one case. A Wisconsin  trial
court
 
                                      104
<PAGE>
has  interpreted "par value" to mean the  subscription price paid for the shares
rather than the lower par value. While the Wisconsin Supreme Court by an  evenly
divided  vote affirmed the trial  court's decision, such affirmation technically
provides no precedential effect because of the court's even division.
 
    Interstate Energy's ability to pay dividends will depend primarily upon  the
ability  of its subsidiaries to pay dividends or otherwise transfer funds to it.
Various financing arrangements and  regulatory requirements will impose  certain
restrictions  on the ability of  Interstate Energy's public utility subsidiaries
to transfer funds to Interstate Energy in  the form of cash dividends, loans  or
advances.
 
    Under  WP&L's current Wisconsin Commission  retail rate order, the Wisconsin
Commission would  have  to approve  the  payment of  any  dividends by  WP&L  to
Interstate  Energy that in the aggregate exceeded $58.1 million per year for the
period from January 1, 1995 to December 31, 1996, if such dividends would reduce
WP&L's average  common equity  ratio below  51.93%. The  Wisconsin  Commission's
dividend limitation is subject to review and modification as part of WP&L's rate
cases.  In connection with its First Mortgage Bond Indenture, WP&L is subject to
restrictions on the amount of net accumulated reinvested earnings available  for
the  payments of  dividends. WP&L  also has  outstanding various  series of WP&L
Preferred Stock that have certain preferential rights relating to the payment of
dividends. Historically, WPLH's ability to  pay dividends has not been  affected
by compliance with the dividend restrictions described above.
 
    Under  Utilities' current IUB retail rate  order, there is no restriction on
the amount of dividends that Utilities is permitted to pay to IES. However,  the
IUB  could in the  future impose conditions  in rate orders  that would have the
effect of limiting  the payment of  dividends by Utilities.  Utilities also  has
outstanding  various  series  of  Utilities Preferred  Stock  that  have certain
preferential rights  relating  to  the payment  of  dividends,  which  Utilities
Preferred  Stock will remain outstanding after the Effective Time if the parties
to the Mergers determine that the  Utilities Reincorporation Merger will not  be
effected.  Historically, Utilities' ability to pay dividends on its common stock
has not been affected by actions by the IUB or compliance with such preferential
dividend rights.
 
    Under IPC's current IUB,  Minnesota Commission and  ICC retail rate  orders,
there  is no restriction on the amount of dividends that IPC is permitted to pay
to its stockholders. However, the IUB, Minnesota Commission or ICC could in  the
future  impose conditions in rate orders that  would have the effect of limiting
the payment of dividends by IPC. IPC also has outstanding various series of  IPC
Preferred Stock that have certain preferential rights relating to the payment of
dividends,  which IPC Preferred Stock (or New  IPC Preferred Stock, in the event
the IPC Reincorporation Merger is consummated) will remain outstanding after the
Effective Time. In addition,  under IPC's First  Mortgage Bond Indenture,  IPC's
ability to pay dividends on the IPC Common Stock is restricted in the event that
certain  financial ratios are not maintained. Historically, IPC's ability to pay
dividends has not been affected by  actions by the IUB, Minnesota Commission  or
ICC,  compliance with such  preferential dividend rights  or compliance with the
dividend restrictions contained in IPC's First Mortgage Bond Indenture.
 
    In addition, under  the Wisconsin Holding  Company Act, Interstate  Energy's
public utility affiliates will be prohibited from lending funds, either directly
or  indirectly, to Interstate Energy. Furthermore,  the SEC, under the 1935 Act,
and the Wisconsin Commission, under the Wisconsin Holding Company Act, will have
the power to preclude  the payment to Interstate  Energy of dividends by  public
utility affiliates thereof. Under the 1935 Act, the SEC will also have the power
to  preclude  the payment  of dividends  by  Interstate Energy.  See "Regulatory
Matters."
 
    It is a condition to consummation of the Mergers that the Interstate  Energy
Common   Stock  be  approved  for  listing  on  the  NYSE  subject  to  official
notification of the issuance.
 
CERTAIN ANTI-TAKEOVER PROVISIONS
 
    The Interstate Energy  Charter, the  Rights Agreement and  the WBCL  contain
provisions that may have the effect of discouraging persons from acquiring large
blocks of Interstate Energy stock or
 
                                      105
<PAGE>
delaying  or preventing a change in control of Interstate Energy. The Interstate
Energy Charter will provide that  the Board of Directors  is to be divided  into
three  classes,  with  staggered terms  of  three  years each.  See  "The Merger
Agreement -- Interstate Energy Board of Directors."
 
    Interstate Energy will be subject to the Rights Agreement pursuant to  which
each  outstanding share  of Interstate  Energy Common  Stock will  have attached
thereto one Common Stock  Purchase Right ("Right")  and each share  subsequently
issued  by Interstate  Energy prior to  the expiration of  the Rights Agreement,
including the shares issued pursuant to the Merger Agreement, will have attached
thereto one Right. Under certain circumstances described below, the Rights  will
entitle the holder thereof to purchase additional shares of Common Stock.
 
    Currently,  the Rights  are not exercisable  and trade with  the WPLH Common
Stock. In the event the Rights become exercisable, each Right (unless held by  a
person  or  group  which beneficially  owns  more  than 20%  of  the outstanding
Interstate Energy Common Stock)  will initially entitle  the holder to  purchase
one-half  share of  Interstate Energy Common  Stock at  a price of  $60 per full
share (equivalent to $30  for each one-half share),  subject to adjustment.  The
Rights  will  only become  exercisable if  a  person or  group has  acquired, or
announced an intention  to acquire,  20% or more  of the  outstanding shares  of
Interstate  Energy  Common  Stock. Under  certain  circumstances,  including the
existence of a  20% acquiring  party, each  holder of  a Right,  other than  the
acquiring  party,  will  be  entitled  to  purchase  at  the  exercise  price of
Interstate Energy Common Stock having a  market value of two times the  exercise
price.  In  the  event  of  the  acquisition  of  Interstate  Energy  by another
corporation subsequent to a party acquiring 20% or more of the Interstate Energy
Common Stock, each holder of a Right  will be entitled to receive the  acquiring
corporation's  common shares  having a  market value  of two  times the exercise
price. The Rights  may be redeemed  at a price  of $.01 per  Right prior to  the
existence of a 20% acquiring party. The Rights will expire on February 22, 1999.
Under  the Rights Agreement, the Interstate Energy  Board will be able to reduce
the thresholds applicable  to the  Rights from  20% to  not less  than 10%.  The
Rights do not have voting or dividend rights and, until they become exercisable,
have no dilutive effect on the earnings of the Company.
 
    Section  180.1150 of the  WBCL provides that  the voting power  of shares of
Wisconsin corporations such as Interstate Energy  held by any person or  persons
acting  as  a group  that hold  in excess  of 20%  of the  voting power  for the
election of  directors is  limited to  10% of  the full  voting power  of  those
shares.  This  restriction  does  not apply  to  shares  acquired  directly from
Interstate Energy or in certain specified transactions or shares for which  full
voting power has been restored pursuant to a vote of shareowners.
 
    Sections  180.1140 to 180.1144  of the WBCL  contain certain limitations and
special  voting  provisions  applicable   to  specified  business   combinations
involving  Wisconsin corporations  such as  Interstate Energy  and a significant
shareowner, unless the board of directors of the Wisconsin corporation  approves
the  business combination or the shareowner's  acquisition of shares before such
shares are  acquired.  Similarly, Sections  180.1130  to 180.1133  of  the  WBCL
contain  special voting provisions applicable  to certain business combinations,
unless specified minimum  price and procedural  requirements are met.  Following
commencement  of a takeover offer, Section  180.1134 of the WBCL imposes special
voting requirements on certain  share repurchases effected at  a premium to  the
market  and on certain asset sales by  the corporation, unless, as it relates to
the potential sale  of assets, the  corporation has at  least three  independent
directors  and a  majority of  the independent  directors vote  not to  have the
provision apply to the corporation.
 
    Finally, Section 196.795(3) of the WBCL provides that no person may hold  or
acquire  directly or indirectly more than 10% of the outstanding securities of a
public utility holding company such as Interstate Energy without the approval of
the Wisconsin Commission.
 
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                     DESCRIPTION OF NEW IPC PREFERRED STOCK
 
    The  terms of the shares of New IPC Preferred Stock, as set forth in the New
IPC Charter,  are substantially  identical  to the  terms of  the  corresponding
shares  of IPC Preferred Stock,  as set forth in the  IPC Charter, as amended by
the IPC Charter Amendment. The New IPC Charter is included as an exhibit to this
Joint Registration Statement. The  bylaws of New IPC,  which are included as  an
exhibit  to this Joint Registration Statement, will be substantially the same as
the  IPC  Bylaws,  except  for  changes  required  by  the  WBCL.  At  the   IPC
Reincorporation  Effective Time, assuming that the IPC Reincorporation Merger is
effected, IPC will merge with and into New IPC, with New IPC being the surviving
corporation  of  the  IPC  Reincorporation  Merger.  The  purpose  of  the   IPC
Reincorporation  Merger  is  to  provide  one  alternative  to  comply  with the
Wisconsin Holding Company Act.  See "Regulatory Matters  -- State Approvals  and
Related Matters." Assuming that the IPC Reincorporation Merger is effected, each
share of IPC Preferred Stock issued and outstanding immediately prior to the IPC
Reincorporation  Effective  Time  (other  than IPC  Dissenting  Shares)  will be
converted into  one share  of  New IPC  Preferred  Stock with  terms  (including
dividend  rights)  and  designations  under the  New  IPC  Charter substantially
identical to those of the converted shares of IPC Preferred Stock under the  IPC
Charter,  as amended  by the  IPC Charter Amendment.  IPC Preferred  Stock and a
corresponding share of New IPC Preferred Stock also differ due to differences in
the laws of  Delaware and  Wisconsin. See  "Comparison of  Shareowner Rights  --
Comparison of Wisconsin, Iowa and Delaware Law."
 
    The  following is a  description of both  (i) the IPC  Common Stock, the IPC
Preferred Stock  and  the  preference  stock, $1.00  par  value,  of  IPC  ("IPC
Preference  Stock")  as  they exist  under  the  IPC Charter  prior  to  the IPC
Reincorporation Merger and (ii) the New IPC Common Stock, the New IPC  Preferred
Stock and the preference stock, $1.00 par value, of New IPC ("New IPC Preference
Stock")  as  they  will  exist  under the  New  IPC  Charter  following  the IPC
Reincorporation Effective Time assuming that  the IPC Reincorporation Merger  is
effected.  As used  in the following  description, unless  otherwise stated, the
term "IPC"  refers  to  IPC  with  respect  to  any  period  prior  to  the  IPC
Reincorporation  Effective Time and to New IPC  with respect to any period after
the IPC  Reincorporation  Effective Time.  Except  as otherwise  indicated,  the
following  summary describes certain  provisions of the IPC  Charter and the New
IPC Charter, and is qualified  in its entirety by  reference to the IPC  Charter
and the New IPC Charter.
 
GENERAL
 
    The  capital stock of IPC  consists of three classes:  IPC Common Stock, par
value $3.50 per share (30,000,000  shares authorized, of which 9,595,028  shares
were outstanding on the IPC Record Date); IPC Preferred Stock, par value $50 per
share   (2,000,000  shares  authorized,  of  which  the  following  series  were
outstanding as of  the IPC  Record Date: 4.36%  Series --  60,455 shares;  4.68%
Series  -- 55,926 shares;  7.76% Series --  100,000 shares; and  6.40% Series --
545,000 shares); and IPC Preference Stock, par value $1.00 per share  (2,000,000
shares  authorized, of  which none  were issued  and outstanding  as of  the IPC
Record Date). The IPC Board is authorized to provide for the issuance from  time
to  time of IPC  Preferred Stock and IPC  Preference Stock in  series and, as to
each series,  to  fix the  designation,  dividend  rates and  time  of  payment,
redemption  price, and liquidation price or preference as to assets in voluntary
liquidation.  Cumulative  dividends,  redemption  provisions  and  sinking  fund
requirements,  to the extent  that some or all  of these features  are or may be
present when IPC Preferred Stock or  IPC Preference Stock is issued, could  have
an  adverse  effect on  the  availability of  earnings  for distribution  to the
holders of the IPC Common Stock or for other corporate purposes.
 
DIVIDEND RIGHTS
 
    Before any dividends may  be paid on  the IPC Common  Stock, the holders  of
each  series of  IPC Preferred  Stock and IPC  Preference Stock  are entitled to
receive all accumulated and  unpaid dividends for past  dividend periods at  the
respective rates provided for the shares of the respective series and classes.
 
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DIVIDEND RESTRICTIONS
 
    In  an Indenture,  dated as of  January 1,  1948, between IPC  and the Chase
National Bank of the  City of New  York (now known as  the Chase Manhattan  Bank
(N.A.)) and Carl E. Buckley, as Trustees (the Chase Manhattan Bank (N.A.) and C.
J.  Heinzelmann,  Successor  Trustees),  as amended  and  supplemented,  IPC has
covenanted that while any of the  bonds issued thereunder (the "IPC Bonds")  are
outstanding,  it  will  not  pay  any  cash  dividends  on  or  make  any  other
distribution with respect  to the IPC  stock unless the  earned surplus of  IPC,
less  the aggregate  amount of  all such  payments and  other distributions made
during the period from December 31, 1946, to the date of the proposed payment of
such dividend or the making of such  distribution that have not been charged  to
such  earned surplus,  shall be  at least  equal to  the amount  of the proposed
dividend or distribution.
 
    IPC has covenanted  that, so  long as  any IPC  Bonds of  the series  issued
subsequent  to May 1,  1963 which were  outstanding on October  15, 1975, remain
outstanding,  it  will  not  pay  any  cash  dividends  on  or  make  any  other
distribution  with respect to the IPC Common  Stock unless the earned surplus of
IPC, less the sum  of (a) the  aggregate amount of all  such payments and  other
distributions  made during the period from December 31, 1946, to the date of the
proposed payment of such dividend or the making of such distributions that  have
not  been charged to such earned  surplus and (b) the excess,  if any, of 15% of
electric operating revenues and 12.5% of the gas and steam operating revenues of
IPC, less  expenditures  made during  such  period  by IPC  by  charges  against
earnings  or earned surplus  during the period,  shall be at  least equal to the
amount of the proposed dividend or distribution.
 
VOTING RIGHTS
 
    EXISTING VOTING RIGHTS  UNDER THE IPC  CHARTER.  Currently,  the holders  of
shares  of each series of IPC Preferred Stock and IPC Preference Stock generally
are not entitled to vote. However, if and whenever full cumulative dividends  on
the  IPC Preferred Stock have not been paid for four quarterly dividend periods,
holders of IPC Preferred Stock are entitled to elect a majority of the Board  of
Directors as then constituted with holders of IPC Common Stock being entitled to
elect  the remaining directors. The right of  the holders of IPC Preferred Stock
to elect directors in such cases  shall cease when full cumulative dividends  on
all  series of IPC Preferred Stock have been paid, or declared and set aside for
payment. In  addition, if  and whenever  full cumulative  dividends on  the  IPC
Preference  Stock have not been paid for six quarterly dividend periods (whether
or not  consecutive), the  size  of the  IPC Board  shall  be increased  by  two
directors  and the holders of IPC Preference Stock, as a class, will be entitled
to elect the additional two directors and, in such cases, holders of IPC  Common
Stock  are  entitled to  elect the  remaining directors,  subject to  the voting
rights of the holders of IPC Preferred Stock at that time, if any. The right  of
the holders of the IPC Preference Stock to elect the two additional directors in
such  cases  shall  cease when  full  cumulative  dividends have  been  paid, or
declared and set aside for payment.
 
    The affirmative  vote  or  consent  of  the  holders  of  various  specified
percentages  of IPC Preferred  Stock is required to:  merge, consolidate or sell
substantially all of the  assets of IPC unless  such transaction is approved  by
the  SEC or other regulatory authority of  the federal government or unless such
transaction  is  undertaken  with  a  subsidiary  of  IPC;  increase  the  total
authorized  amount of IPC Preferred Stock or authorize any other preferred stock
on a parity therewith with respect to dividends or liquidation rights; issue any
additional shares of IPC  Preferred Stock on a  parity with the outstanding  IPC
Preferred  Stock  with respect  to payment  of  dividends or  liquidation rights
unless (i) IPC's consolidated  gross income for  12 consecutive calendar  months
within  a period  of 15 calendar  months immediately preceding  such issuance is
equal to at least 150% of IPC's aggregate consolidated interest charges and  the
annual  dividend charges  of all  IPC Preferred  Stock that  will be outstanding
immediately after such  issuance and  (ii) the stated  capital of  IPC less  the
liquidation  preferences of the IPC Preferred  Stock and IPC Preference Stock is
at least equal  to the aggregate  par value of  the IPC Common  Stock; issue  or
assume  any  unsecured  debt  for  any purpose  other  than  to  refund existing
unsecured debt, redeem any  indebtedness pursuant to  authorization by state  or
federal  regulatory authority, or redeem any outstanding shares of IPC Preferred
Stock if after such transaction IPC's
 
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aggregate unsecured debt exceeds 20% of IPC's then outstanding secured debt  and
total  equity; authorize  any class  of stock with  rights greater  than the IPC
Preferred Stock; or change adversely the express terms and provisions of the IPC
Preferred Stock.
 
    In the event that the IPC Charter Amendment is approved at the IPC  Meeting,
holders  of IPC Preferred Stock will thereafter  have one vote per share, voting
together as a class with  the holders of IPC  Common Stock (except as  otherwise
provided by law or specifically set forth in IPC's Charter as summarized above),
on  all matters to come before a vote  of stockholders of IPC. See "Amendment to
IPC Restated Certificate of Incorporation."
 
    The affirmative  vote  or  consent  of  the  holders  of  various  specified
percentages  of IPC Preference  Stock is required to:  authorize or increase the
authorized amount  of  any class  of  stock with  rights  greater than  the  IPC
Preference  Stock other than  IPC Preferred Stock;  change adversely the express
terms of  the  IPC Preference  Stock;  increase  the authorized  amount  of  IPC
Preference  Stock; authorize or  increase the authorized amount  of any class of
stock with rights on a parity to the IPC Preference Stock; merge, consolidate or
sell substantially all the assets of IPC unless such transaction is approved  by
the SEC or any regulatory authority of the federal government.
 
    VOTING   RIGHTS  UNDER  THE  NEW  IPC  CHARTER.     In  the  event  the  IPC
Reincorporation Merger is effected, the holders of New IPC Preferred Stock  will
have  the right to cast one  vote per share, voting with  the holders of New IPC
Common Stock,  on all  matters submitted  to  a vote  of New  IPC's  shareowners
including  the  election of  directors. In  addition, where  the holders  of IPC
Preferred Stock and  IPC Preference  Stock had  a right  to vote  under the  IPC
Charter,  the holders of  New IPC Preferred  Stock and New  IPC Preference Stock
will have the right to vote as separate classes on such matters.
 
REDEMPTION PROVISIONS
 
    IPC, at its option, generally  may redeem the whole or  any part of the  IPC
Preferred  Stock or IPC Preference Stock of any  series or of all series upon at
least 30 days  written notice. However,  IPC may  not redeem any  shares of  the
6.40%  IPC Preferred Stock before May 1, 2003 if the redemption is being made to
refund such IPC Preferred Stock with funds  with an effective cost of less  than
6.40% per annum.
 
    IPC  has issued  and outstanding  three series  of IPC  Preferred Stock with
optional sinking fund  provisions and  one series  of IPC  Preferred Stock  with
mandatory sinking fund provisions.
 
    Under  the provisions of the IPC Charter,  beginning in 2003 IPC is required
to redeem annually $1.4  million of IPC's 6.40%  Preferred Stock, par value  $50
per share (27,250 shares).
 
CHANGE IN CONTROL
 
    The  IPC Charter  and the DGCL  contain provisions that  could discourage or
make more difficult a change in control of IPC, including provisions requiring a
higher  vote  for   certain  business  transactions.   Assuming  that  the   IPC
Reincorporation  Merger is effected, following the IPC Reincorporation Effective
Time, the  rights  of holders  of  New  IPC Preferred  Stock,  including  rights
relating  to a potential change  in control of New IPC,  will be governed by the
WBCL. For a discussion of the differences between such provisions under the DGCL
and the WBCL, see "Comparison of  Shareowner Rights -- Comparison of  Wisconsin,
Iowa and Delaware Law." Following consummation of the Mergers, Interstate Energy
will be an Interested Stockholder of IPC or New IPC, as the case may be, as such
term  is defined in the IPC Charter or  the New IPC Charter, as applicable. As a
result, a  supermajority  vote of  the  holders  of outstanding  shares  of  IPC
Preferred  Stock  or New  IPC  Preferred Stock,  as the  case  may be,  would be
required to  effect certain  transactions constituting  a change  in control  in
accordance  with  the  terms of  the  IPC Charter  or  the New  IPC  Charter, as
applicable.
 
LIQUIDATION RIGHTS
 
    In the event of  liquidation, holders of all  series of IPC Preferred  Stock
are  entitled to $50 per share, in  the event of involuntary liquidation, or the
then applicable redemption prices in the case of voluntary liquidation, plus  in
either   case,  an  amount  equal  to  all  accumulated  and  unpaid  dividends.
 
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Following distributions  to  holders of  IPC  Preferred Stock,  holders  of  IPC
Preference Stock are entitled to the amount of consideration originally received
by  IPC  for  such shares,  in  the  event of  involuntary  liquidation,  or the
applicable  amount  determined  to  be   payable  in  the  event  of   voluntary
liquidation.  Following the distributions to the  holders of IPC Preferred Stock
and IPC Preference Stock, the  holders of IPC Common  Stock are entitled to  the
remaining  assets. If upon  any such liquidation  the assets distributable among
the holders of IPC Preferred Stock, of  all series, or IPC Preference Stock,  of
all  series, are insufficient to  pay in full the  amounts to which such holders
are entitled, the amount distributable to the holders of IPC Preferred stock, of
all series, or IPC Preference Stock, of all series, as the case may be, will  be
apportioned  among them ratably in  proportion to the amounts  to which they are
respectively then entitled.
 
PREEMPTION AND SUBSCRIPTION RIGHTS
 
    No holder of IPC Common Stock,  IPC Preferred Stock or IPC Preference  Stock
has  the preemptive  right to purchase  or subscribe for  any additional capital
stock of IPC.
 
                        COMPARISON OF SHAREOWNER RIGHTS
 
    If the Mergers are consummated, the persons who were holders of WPLH  Common
Stock  immediately  prior  to  the Mergers  will  remain  common  shareowners of
Interstate Energy immediately after consummation of the Mergers and their rights
will be governed by the Interstate Energy Charter, the Interstate Energy  Bylaws
and the WBCL. The WPLH Charter, as amended by the WPLH Charter Amendments, which
are  being submitted for  shareowner approval at  the WPLH Meeting,  will be the
Interstate Energy  Charter  at  the  Effective Time.  See  "Amendments  to  WPLH
Restated  Articles of Incorporation."  The Interstate Energy  Bylaws will be the
WPLH Bylaws as in effect at the Effective Time.
 
    The holders of IES and IPC  Common Stock, upon consummation of the  Mergers,
will  become holders of Interstate Energy Common  Stock and their rights will be
governed by the Interstate Energy Charter, the Interstate Energy Bylaws and  the
WBCL.  The  Interstate  Energy  Charter and  the  Interstate  Energy  Bylaws are
different in certain respects from the IES  Charter and the IPC Charter and  the
IES  Bylaws and IPC  Bylaws. In addition, certain  differences exist between the
WBCL,  IBCA  and  DGCL  with  respect  to  shareowners'  rights.  While  it   is
impracticable to compare all these differences, material significant differences
between  the Interstate Energy Charter and  the Interstate Energy Bylaws, on the
one hand, and the IES Charter and IPC Charter and the IES Bylaws and IPC Bylaws,
on the  other hand,  are summarized  below under  "-- Comparison  of  Interstate
Energy  Charter and  Bylaws to  IES and  IPC Charter  and Bylaws,"  and material
similarities and  differences between  the  WBCL, the  IBCA  and the  DGCL  with
respect  to shareowners'  rights are  summarized below  under "--  Comparison of
Wisconsin, Iowa and Delaware Law."
 
    The following discussion is not intended to be complete and is qualified  in
its  entirety by reference  to the Interstate Energy  Charter and the Interstate
Energy Bylaws which are  filed as exhibits to  the Joint Registration  Statement
and  incorporated  by reference  herein, the  WBCL,  IBCA and  DGCL and  the IES
Charter, the IPC Charter, the IES Bylaws and the IPC Bylaws.
 
COMPARISON OF INTERSTATE ENERGY CHARTER AND BYLAWS TO IES AND IPC CHARTER AND
BYLAWS
 
    BOARD OF DIRECTORS.  The  IES Charter provides that  the IES Board shall  be
comprised  of not less  than five members, as  fixed in the  IES Bylaws. The IES
Bylaws provide that the  IES Board will consist  of nine directors effective  on
the date of the IES Meeting. The IES Board currently consists of nine directors.
The  IPC Charter provides that the number of directors on the IPC Board shall be
fixed by the IPC Bylaws. The IPC Bylaws provide that the IPC Board will  consist
of  seven directors.  The IPC Board  currently consists of  seven directors. The
Interstate Energy Charter  will provide  that the  number of  directors will  be
fixed  by the Interstate  Energy Bylaws, but  shall not be  less than seven. The
Interstate Energy Bylaws will be amended  to provide that at the Effective  Time
the number of
 
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directors  on  the Interstate  Energy Board  will  be set  at fifteen,  with six
directors designated  by  WPLH,  six  directors  designated  by  IES  and  three
directors  designated by IPC.  The Interstate Energy Board,  like the WPLH Board
and the IPC Board, will be classified into three classes.
 
    CERTAIN SHARE  ACQUISITIONS  AND BUSINESS  COMBINATIONS.   The  IPC  Charter
contains  provisions that have the effect of discouraging persons from acquiring
large blocks of IPC stock or delaying or preventing a change in control of  IPC.
Under  certain circumstances, these  provisions could have  the effect of, among
other things  (i) prohibiting  a  5% stockholder  from  engaging in  a  business
combination with IPC unless certain requirements are satisfied, (ii) prohibiting
the payment of a market premium (I.E., greenmail) to a 5% stockholder, and (iii)
prohibiting  a potential  tender offeror  from engaging  in an  unequal two-tier
tender offer. The DGCL, in addition,  contains certain provisions that have  the
effect  of  discouraging persons  from acquiring  large blocks  of IPC  stock or
delaying or preventing a change in control of IPC. Under certain  circumstances,
these provisions could have the effect of, among other things, prohibiting a 10%
stockholder  from engaging  in a business  combination with IPC  for three years
following the  date such  10% interest  was  acquired. See  " --  Comparison  of
Wisconsin,  Iowa and Delaware Law" below for  a more complete discussion of such
provisions,  including  the  circumstances  under  which  such  provisions   are
triggered.
 
    The  IES  Charter  contains  certain  provisions  that  have  the  effect of
discouraging persons from  acquiring large blocks  of IES stock  or delaying  or
preventing  a  change  in control  of  IES. Under  certain  circumstances, these
provisions could have the  effect of, among other  things, (i) prohibiting a  5%
shareholder  from engaging  in a  business combination  with IES  unless certain
requirements are satisfied,  (ii) prohibiting  the payment of  a market  premium
(I.E.,  greenmail) to a 5% shareholder  and (iii) prohibiting a potential tender
offeror from engaging in  an unequal two-tier tender  offer. The IBCA is  silent
with regard to certain share acquisitions and business combinations.
 
    Certain  provisions of the WBCL have the effect of discouraging persons from
acquiring large  blocks of  WPLH stock  or delaying  or preventing  a change  in
control  of WPLH. Under  certain circumstances, these  provisions could have the
effect of, among other things, (i) reducing the voting power of shares  acquired
by  a  20% shareowner,  (ii) prohibiting  a  10% shareowner  from engaging  in a
business combination with WPLH for three years following the date of acquisition
of such 10% interest, (iii) prohibiting a potential tender offeror from engaging
in an unequal two-tier tender offer and (iv) prohibiting the payment of a market
premium (I.E., greenmail) to a 5% shareowner  who has held such shares for  less
than  two years. See " -- Comparison  of Wisconsin, Iowa and Delaware Law" below
for a more complete discussion  of such provisions, including the  circumstances
under which such provisions are triggered.
 
    REMOVAL OF DIRECTORS.  The IES Charter and IES Bylaws provide that directors
may  be removed only for  cause. The IPC Charter  provides that directors may be
removed only  for  cause,  except  that  in  certain  situations  involving  the
non-payment of dividends on the IPC Preferred Stock, a majority of the directors
may be replaced by nominees of the preferred stockholders. The Interstate Energy
Charter  and Interstate Energy Bylaws are silent as to the removal of directors.
The WBCL provides that directors may be  removed with or without cause but  only
at  a special meeting called  for the purpose of  removing the director provided
that the notice of such meeting states  the purpose of the meeting is to  remove
the  director.  For a  discussion of  who can  call a  special meeting,  see "--
Special Meetings of Shareowners; Shareowner Action By Written Consent" below.
 
    VACANCIES ON THE BOARD OF DIRECTORS.  The IES Bylaws provide that  vacancies
caused  by an increase in  the size of the  board, or by any  other cause may be
filled by the remaining directors. Directors filling such vacancies shall  serve
for  the unexpired term of  the vacant directorship or the  full term of the new
directorship.
 
    The IPC Charter and IPC Bylaws provide  that vacancies on the IPC Board  and
newly  created directorships resulting from an increase in the authorized number
of directors may be filled by a  majority vote of the directors then in  office,
even  though they may  be less than a  quorum, provided that, if  at the time of
filling any vacancy or newly created directorship, the directors then in  office
 
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constitute  less  than  a  majority  of  the  whole  board,  any  stockholder or
stockholder group holding  at least ten  percent of the  total number of  shares
entitled  to vote for directors  may petition the Delaware  Court of Chancery to
order an election to  fill such vacancies or  newly created directorships or  to
replace  the directors  chosen by the  directors then in  office. Such directors
shall serve until the next election of the class for which they were selected.
 
    The Interstate Energy Charter provides that  any vacancies may be filled  by
the  remaining directors.   If the remaining  directors are less  than a quorum,
vacancies may be filled by the affirmative  vote of a majority of all  directors
remaining  in office. Directors selected by  majority vote of the directors then
in office shall serve until the next annual meeting of the shareowners.
 
    AMENDMENTS TO ARTICLES OF  INCORPORATION.  The IES  Charter is silent as  to
amendment procedures, except that an 80% vote of the outstanding voting stock is
required  to amend the provisions  governing business combinations or amendments
of the article provisions regarding business combinations (except in  situations
where  the  proposed  article  amendments  are  unanimously  recommended  by the
Company's Unaffiliated  Directors). The  IBCA requires  that, unless  a  greater
proportion   is  required  by  the  articles,  amendments  to  the  articles  of
incorporation must  be approved  by the  affirmative vote  of the  holders of  a
majority  of  the  voting power  of  the  shares entitled  to  vote.  In certain
circumstances, a vote by class or series is required.
 
    The IPC Charter provides that amendments thereto shall be made in the manner
prescribed by statute. The DGCL provides that amendments to the IPC Charter must
be approved by a  majority of the  outstanding stock entitled to  vote and by  a
majority of the outstanding stock entitled to vote as a class.
 
    The  Interstate Energy Charter is silent  with regard to amendments thereto.
The WBCL generally  provides that  amendments to the  articles of  incorporation
must  be approved by  a majority of the  votes cast, unless  a greater or lesser
proportion is required by the articles or bylaws.
 
    AMENDMENT TO BYLAWS.  The  IES Charter provides that  the IES Board has  the
authority  to  make  and alter  the  IES Bylaws,  subject  to the  power  of the
shareholders to change or repeal the IES  Bylaws contained in the IBCA. The  IPC
Charter  provides that the IPC  Board may make and  amend the IPC Bylaws without
any action  on the  part  of the  stockholders, subject  to  the rights  of  the
stockholders  to amend bylaws made by directors. The IPC Bylaws provide that the
IPC Bylaws may be amended and new bylaws made at any annual, regular or  special
meeting of stockholders by the affirmative vote of a majority in interest of the
stock  issued, outstanding  and entitled to  vote. The  Interstate Energy Bylaws
provide that  the Interstate  Energy Bylaws  may be  amended by  the  Interstate
Energy Board at any regular or special meeting of the Interstate Energy Board or
by  the shareowners  by the  affirmative vote of  a majority  of the outstanding
voting stock  possessed  by all  owners  at any  annual  or special  meeting  of
shareowners (provided that the notice calling any special meeting must state the
proposal to amend the Bylaws).
 
    VOTING/CUMULATIVE  VOTING.  The IES Charter  provides that each share of IES
Common Stock is  entitled to  one vote  on each matter  submitted to  a vote  of
shareholders.  The  IES  Charter  does  not  provide  for  cumulative  voting in
connection with the election of directors.  Pursuant to the IES Charter,  shares
of  IES Preferred Stock may have such voting rights as are designated by the IES
Board at the time of issuance. The  IPC Charter provides that each share of  IPC
Common  Stock is  entitled to  one vote on  each matter  submitted to  a vote of
stockholders. The IPC  Charter further  provides that holders  of IPC  Preferred
Stock and IPC Preference Stock have no votes except when certain arrearages have
occurred  with respect to  the IPC Preferred  Stock and IPC  Preference Stock or
when certain specified transactions  adversely affect the  rights of holders  of
either  class  of such  shares. In  such case,  the holders  of such  shares are
entitled to one vote,  voting as separate classes,  on each matter submitted  to
such  class for  a vote. The  IPC Charter  provides that there  is no cumulative
voting for any  class of stock.  The IPC Charter  is proposed to  be amended  to
provide  certain voting rights to holders of IPC Preferred Stock. See "Amendment
to IPC Restated Certificate of Incorporation." The Interstate Energy Charter and
Interstate Energy  Bylaws  are  silent  with  regard  to  the  voting  power  of
 
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holders  of  Interstate  Energy  Common  Stock.  The  WBCL  provides  that  each
outstanding share  is  entitled  to one  vote  on  each matter  voted  on  at  a
shareowner  meeting. The  WBCL further provides  that shareowners do  not have a
right to  cumulative  voting  unless the  articles  of  incorporation  otherwise
provide, which the Interstate Energy Charter does not so provide.
 
    SPECIAL  MEETINGS OF SHAREOWNERS; SHAREOWNER ACTION BY WRITTEN CONSENT.  The
IES Bylaws provide that  special meetings of IES  shareholders may be called  by
the  Chairman of the Board,  the President, the IES Board  or the holders of not
less than 10% of all the shares entitled to vote at the meeting. The IPC  Bylaws
provide  that special  meetings of  IPC stockholders  may be  called by  the IPC
Board, the Chairman of the Board, the President, a Vice-President or the holders
of at  least  twenty-five percent  of  the  shares issued  and  outstanding  and
entitled  to vote. The Interstate Energy Bylaws provide that special meetings of
the shareowners  may  be called  by  the Chairperson  of  the Board,  the  Chief
Executive  Officer or the Interstate Energy Board. Pursuant to the WBCL, special
meetings of shareowners may also be called by the holders of at least 10% of the
votes entitled to be cast on any issue.
 
    The IES Bylaws  are silent  as to whether  shareholders may  take action  by
written  consent without  a meeting.  The IBCA  authorizes shareholders  to take
action without a meeting by written consents  signed by the holders of not  less
than  90% of the votes entitled to be cast. The IPC Charter is also silent as to
whether stockholders may take  action by written consent  in lieu of a  meeting.
The  DGCL allows  stockholders to take  action in  lieu of a  meeting by written
consent signed by  the holders  of outstanding stock  having not  less than  the
number  of votes that would be necessary  to authorize such action at a meeting.
The Interstate Energy Bylaws are  also silent regarding whether shareowners  may
take  action by written consent without  a meeting. The WBCL permits shareowners
to take action without a meeting by unanimous written consent.
 
    INDEMNIFICATION/LIMITATION OF LIABILITY.  The IES Charter provides that  IES
shall  indemnify any director, officer, employee  or agent to the fullest extent
permitted under the IBCA. The IES Charter further authorizes IES to purchase and
maintain insurance for any such person or  any person serving at the request  of
IES  as a director, officer, employee or agent of another enterprise against any
liability incurred as a result of the person serving in such official  capacity.
The  IES Charter  also limits the  personal liability of  directors for monetary
damages for breach of their fiduciary  duties, except for liability relating  to
(i)  any breach  of the  director's duty  of loyalty  to the  corporation or its
shareholders, (ii)  acts  or  omissions  not in  good  faith  or  which  involve
intentional  misconduct or knowing  violation of the  law, (iii) any transaction
from which the director derived an  improper personal benefit, or (iv)  unlawful
distributions.
 
    The IPC Bylaws provide that IPC shall indemnify any person who is a party or
threatened to be made a party to any legal proceeding by reason of the fact that
such person is or was a director, officer, employee or attorney of IPC, or is or
was  serving at the request of IPC  as a director, officer, employee or attorney
of another enterprise, against expenses (including attorneys' fees),  judgments,
fines  and amounts paid  in settlement actually and  reasonably incurred by such
person. This  right  of indemnity  includes  the advancement  of  expenses  upon
receipt  of  an undertaking  to repay  upon specified  conditions. The  right to
indemnification  does  not  extend  to  matters  in  which  the  person  seeking
indemnification  is  found liable  to the  corporation by  a court  of competent
jurisdiction, by a majority of the directors who are not seeking indemnification
or by independent  counsel appointed by  the IPC  Board unless and  only to  the
extent  that a court determines such person is fairly and reasonably entitled to
indemnification despite  a final  determination of  liability. The  IPC  Charter
limits  the personal  liability of  directors for any  acts or  omissions in the
performance of their duties as directors to the full extent permitted under  the
DGCL.
 
    The  Interstate Energy Bylaws provide that Interstate Energy shall indemnify
a director or officer or any person serving at the request of Interstate  Energy
as  a director,  officer, agent  or employee  of another  enterprise against all
reasonable expenses (including attorneys' fees) incurred in connection with  any
threatened  or pending legal proceeding  to which the director  or officer was a
party because
 
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such person was a director or officer  to the extent such person was  successful
on  the  merits  or  otherwise  in the  defense  of  the  threatened  or pending
proceeding. The Interstate Energy Bylaws further provide that Interstate  Energy
shall  indemnify directors and officers against liability incurred in threatened
or pending  legal proceedings  to which  the  director or  officer was  a  party
because  such party was a director or  officer unless the liability was incurred
because the director  or officer (i)  willfully failed to  deal fairly with  the
corporation or its shareowners in connection with a matter in which the director
or  officer  had a  material conflict  of interest,  (ii) violated  criminal law
unless the  director or  officer had  reasonable  cause to  believe his  or  her
conduct  was  lawful or  had no  reasonable  cause to  believe such  conduct was
unlawful, (iii)  engaged in  a transaction  from  which he  or she  received  an
improper  personal benefit, or (iv) engaged in willful misconduct. This right of
indemnity includes the advancement of expenses upon receipt of an undertaking to
repay upon specified  conditions. The  right to indemnification  (except in  the
event  of a successful defense, in which case such indemnification is automatic)
will be determined at the indemnified party's election by (i) majority vote of a
quorum of disinterested directors, (ii) independent legal counsel, (iii) a panel
of three arbitrators,  (iv) majority vote  of the shareowners,  (v) a court,  or
(vi) such other method provided for in any additional right to indemnification.
 
COMPARISON OF WISCONSIN, IOWA AND DELAWARE LAW
 
    As  described below, the  DGCL, IBCA and  WBCL generally provide shareowners
with similar rights and protections. A comparison  of the DGCL as it applies  to
IPC,  the IBCA as it  applies to IES and  the WBCL as it  applies to WPLH is set
forth below:
 
    CLASSIFIED BOARD OF DIRECTORS; REMOVAL  OF DIRECTORS; VACANCIES.  The  DGCL,
IBCA  and WBCL  each allow the  board of  directors to be  divided into classes.
Under the DGCL,  directors serving  on a classified  board of  directors may  be
removed  only  for  cause  unless  the  certificate  of  incorporation  provides
otherwise. Under both  the IBCA  and WBCL, absent  a provision  to the  contrary
contained  in the corporation's articles of  incorporation or bylaws, a director
can be removed with or without cause  by the affirmative vote of the holders  of
the  proportion of the voting power of the  shares of the classes or series such
director represents sufficient to elect such director.
 
    The DGCL provides that vacancies on the board of directors will be filled as
the certificate of incorporation or the bylaws provide, and that in the  absence
of  any such certificate of incorporation  or bylaw provision, vacancies will be
filled by the board of directors. The IBCA and WBCL both provide that unless the
articles of  incorporation otherwise  provide, vacancies  may be  filled by  the
shareowners  or by the affirmative vote of  a majority of the directors, even if
the directors remaining in  the office constitute less  than a quorum. The  IBCA
and  WBCL also  both provide that  if the vacant  office was held  by a director
elected by a voting  group of shareowners, only  the shareowners of that  voting
group  may  vote to  fill the  vacancy if  filled by  shareowners, and  only the
remaining directors elected by that voting group may vote to fill the vacancy if
filled by the directors.
 
    INTERESTED DIRECTOR TRANSACTIONS.  The DGCL, IBCA and WBCL each provide that
contracts or transactions in  which one or more  of the corporation's  directors
have  an  interest  ("Interested Contracts  or  Transactions") are  not  void or
voidable solely because of such interest or because such director was present at
the directors' or shareowners' meeting where such contracts or transactions were
approved,  provided  certain  conditions   are  met.  Interested  Contracts   or
Transactions  may be approved by a  majority vote of the disinterested directors
or by vote of disinterested shareowners  if the material facts of the  contracts
or  transactions and the  director's interest in  such contracts or transactions
are fully disclosed and a vote  is taken in good faith. Furthermore,  Interested
Contracts  or Transactions may be approved if such contracts or transactions are
shown to  be  fair and  reasonable  to the  corporation  at the  time  they  are
authorized,  approved or ratified  by the board of  directors or shareowners and
separate disinterested  shareowner or  disinterested  director approval  is  not
required.
 
    INDEMNIFICATION  OF DIRECTORS AND OFFICERS.  The WBCL provides for mandatory
indemnification of  a  director  or  officer  against  certain  liabilities  and
expenses  if the director or officer was a  party to a proceeding because of his
or her status as such: (a) to the extent such director or officer is  successful
on
 
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the merits or otherwise in the defense of the proceeding; and (b) in proceedings
in  which the  director or  officer is  not successful  in the  defense thereof,
unless it is determined that the liability was incurred because the director  or
officer  breached  or failed  to  perform a  duty  that he  or  she owes  to the
corporation and the  breach or  failure to  perform constitutes:  (i) a  willful
failure  to deal  fairly with the  corporation or its  shareowners in connection
with a  matter in  which the  director or  officer has  a material  conflict  of
interest;  (ii) a violation of criminal law,  unless the director or officer had
reasonable cause to believe that his or her conduct was lawful or no  reasonable
cause  to believe that his or her conduct was unlawful; (iii) a transaction from
which the  director or  officer derived  an improper  personal profit;  or  (iv)
willful  misconduct.  Indemnification  under the  WBCL  is not  required  if the
director or officer  has previously  received indemnification  from any  person,
including  the corporation,  in connection  with the  same proceeding.  The WBCL
provides that a corporation's articles of incorporation may limit its obligation
to indemnify directors and officers. The WBCL specifically states that it is the
public policy of Wisconsin  to require or  permit indemnification in  connection
with  a proceeding involving securities regulation, as described therein, to the
extent otherwise required or permitted under the WBCL.
 
    The IBCA provides that a corporation shall indemnify a director or  officer,
made  party to a proceeding because of his or her status as such, who was wholly
successful on the merits or otherwise  in the defense of such proceeding.  Under
the  IBCA, the corporation may indemnify a director or officer against liability
incurred in a  proceeding provided the  director or officer:  (a) acted in  good
faith;  (b) reasonably believed that his or her conduct was in the corporation's
best interests (in the  case of conduct in  such person's official capacity)  or
not opposed to the corporation's best interests (in all other cases); (c) in the
case  of any criminal proceeding,  he or she had  no reasonable cause to believe
that the conduct was unlawful; (d)  was not adjudged liable to the  corporation;
and  (e) did not receive an improper  personal benefit. The IBCA provides that a
corporation's articles of  incorporation may limit  its obligation to  indemnify
directors and officers.
 
    The  DGCL provides that  a director or officer  shall be indemnified against
expenses (including attorneys'  fees) actually  and reasonably  incurred to  the
extent  such director or officer has been  successful on the merits or otherwise
in any action brought  against such director  or officer because  of his or  her
status  as such. With respect to a  third-party action, the DGCL provides that a
corporation may  indemnify  a director  or  officer against  liability  if  such
director or officer (a) acted in good faith and in a manner he or she reasonably
believed  to be in or  not opposed to the best  interests of the corporation and
(b) with respect to any criminal action, had no reasonable cause to believe  his
or  her conduct was unlawful. With respect  to claims brought against a director
or officer by or in the right  of the corporation, such director or officer  may
be  indemnified  against  expenses  (including  attorneys'  fees)  actually  and
reasonably incurred by him or her  except that no indemnification shall be  made
in  respect to any claim as to which such director or officer was adjudged to be
liable to  the corporation  unless and  only  to the  extent that  the  Delaware
Chancery Court determines otherwise.
 
    LIMITED  LIABILITY OF DIRECTORS.  The DGCL,  IBCA and WBCL each provides for
the limitation or elimination of the personal liability of a company's directors
to the  company or  its  shareowners for  monetary damages  for  a breach  of  a
director's  fiduciary duty. This immunity is  automatic under Wisconsin law, but
must be  provided for  in the  certificate or  articles of  incorporation  under
Delaware  and Iowa law.  In any case,  directors cannot be  immunized in certain
instances including: (i) breach of the  duty of loyalty; (ii) acts or  omissions
not  in good faith that involve intentional misconduct or a knowing violation of
law; (iii) unlawful distributions; and  (iv) transactions in which the  director
received  an improper personal benefit. Other limitations specific to each state
also exist.
 
    AMENDMENT OF ARTICLES.  The DGCL, IBCA and WBCL each provide that the  board
of  directors may propose amendments to  a corporation's certificate or articles
of incorporation,  respectively. Under  the DGCL,  proposed amendments  must  be
approved  by the  affirmative vote of  the holders  of a majority  of the voting
power of  the shares  entitled to  vote. Under  the IBCA  and WBCL,  unless  the
articles  of  incorporation,  bylaws  adopted  under  authority  granted  in the
articles, the board (if the  board is proposing the  amendment), or the IBCA  or
WBCL, as applicable, requires a greater vote or
 
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vote by voting groups, a proposed amendment is adopted if approved by a majority
of  the votes cast by  every voting group entitled to  vote on the amendment. In
addition, each of the DGCL, IBCA  and WBCL require that certain amendments  must
be  approved by a  separate vote of a  class or series of  stock if, among other
things, the amendment would adversely affect  the rights or preferences of  such
shares.
 
    AMENDMENT  OF BYLAWS.  Under  the DGCL, the power  to adopt, amend or repeal
the  bylaws  is  vested  in  the  stockholders  entitled  to  vote,  unless  the
certificate  of incorporation  confers the power  to adopt, amend  or repeal the
bylaws upon  the directors.  Under the  IBCA and  WBCL, unless  reserved by  the
certificate  of incorporation to  the shareowners, the power  to adopt, amend or
repeal the bylaws is generally vested in the directors, subject to the power  of
the  shareowners to adopt, amend, or  repeal bylaws adopted, amended or repealed
by the directors.
 
    VOTE REQUIRED  FOR CERTAIN  MERGERS, CONSOLIDATIONS  OR DISSOLUTIONS.    The
DGCL,  IBCA and WBCL each require shareowner approval (except as indicated below
and for certain mergers between a  parent company and its 90% owned  subsidiary)
by the shareowners of each corporation that is party to a plan of merger and the
selling  corporation for  the sale by  the corporation of  substantially all its
assets if not in  the usual or  regular course of business.  (The DGCL does  not
refer  to the usual  or regular course  of business). The  IBCA and WBCL further
provide for a shareowner vote of  the corporation whose shares will be  acquired
in  a  statutory share  exchange.  Each of  the DGCL,  IBCA  and WBCL  require a
shareowner vote to approve the dissolution of a corporation.
 
    The DGCL provides that the vote required  to approve a plan of merger,  sale
of  substantially all the assets or dissolution is a majority of the outstanding
stock of the corporation entitled to vote thereon. Under the IBCA and the  WBCL,
unless  a higher voting requirement is  imposed by the articles of incorporation
or, in the case of the WBCL by the bylaws adopted under authority granted by the
articles of incorporation, or, in the case of the IBCA by the board of directors
requiring a  higher  vote as  a  condition to  its  submission of  the  plan  to
shareowners,  the vote  required to  approve a  plan of  merger, statutory share
exchange, sale  of  substantially all  assets  not  in the  ordinary  course  of
business or dissolution is a majority of the voting power of all shares entitled
to  vote of each corporation whose shareowners have a right to vote; approval of
a plan of merger  or statutory share exchange  (and in the case  of the WBCL,  a
sale   of  substantially  all  assets  or  dissolution)  also  may  require  the
affirmative vote of one or more classes or series of stock.
 
    Neither the IBCA  nor the WBCL  requires the  vote of the  shareowners of  a
surviving  corporation  in  a  merger  if  (i)  the  corporation's  articles  of
incorporation will  not be  amended in  the transaction  (except for  amendments
permitted  to be made  by the board  without a shareowner  vote under the WBCL),
(ii) shareowners of the corporation immediately before the effective date of the
transaction  will  hold  the  same  number  of  shares  with  identical   rights
immediately  after the  effective date, (iii)  the number of  shares entitled to
vote immediately after the merger (plus shares issuable upon certain conversions
or pursuant to certain rights)  does not exceed by more  than 20% the number  of
shares  entitled to vote immediately before the transaction, and (iv) the number
of  participating  shares  of  the   corporation  (outstanding  shares  of   the
corporation  that entitle their  holders to participate,  without limitation, in
distributions by the corporation) immediately after the merger, plus the  number
of  participating shares of the corporation issuable on the conversion of, or on
the exercise of rights to purchase,  securities issued in the transaction,  will
not  exceed  by  more  than  20%  the  number  of  participating  shares  of the
corporation immediately  before the  transaction. The  DGCL similarly  does  not
require  a stockholder vote of the stockholders  of a surviving corporation to a
merger if  (i)  the agreement  of  merger does  not  amend in  any  respect  the
surviving  corporation's  certificate,  (ii)  each  share  of  stock outstanding
immediately prior to the merger is  identical to outstanding or treasury  shares
following  the  merger,  and  (iii)  no  shares  of  stock  (and  no  securities
convertible into shares of stock) are to be issued pursuant to the merger or the
number of shares  issued (or the  securities convertible into  shares of  stock)
does not exceed 20% of the number of shares outstanding immediately prior to the
merger.
 
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    CLASS VOTE FOR CERTAIN REORGANIZATIONS.  The IBCA and the WBCL both provide,
with  certain exceptions, that a  class or series of  shares of a corporation is
entitled to vote on a plan of merger  or statutory share exchange as a class  or
series  if any provision of the plan would, if contained in a proposed amendment
to the articles of incorporation, entitle the class or series of shares to  vote
as  a class or series and, in the case of an exchange, if the class or series is
included in the plan of exchange. The DGCL does not contain similar  provisions.
In   addition  to   the  voting  requirements   discussed  above,  anti-takeover
legislation adopted in Wisconsin and Delaware imposes additional restrictions on
mergers and  other business  combinations between  certain shareowners  and  the
corporation. See "-- Anti-Takeover Statutes."
 
    SHAREOWNER  ACTION  BY  CONSENT.    The  DGCL,  IBCA  and  WBCL  each permit
shareowners to take action  without a meeting by  written consent. However,  the
DGCL  and  IBCA both  allow  corporations to  opt  out of  such  written consent
provisions by  so stating  in their  certificate or  articles of  incorporation,
respectively.  To approve an action  in lieu of meeting  by written consent, the
DGCL requires each written  consent to be signed  by the holders of  outstanding
stock  having not less than the minimum  number of votes that would be necessary
to approve such action at  a meeting where all  shares entitled to vote  thereon
were  present and voted. The IBCA requires  written consents to be signed by the
holders of 90%  of the votes  entitled to be  cast for shareowner  action to  be
approved.   The  WBCL  requires   unanimous  consent  unless   the  articles  of
incorporation provide for action by less than unanimous consent.
 
    STATUTORY SHAREOWNER  LIABILITY.   The  WBCL  provides that  shareowners  of
Wisconsin  corporations are personally liable  up to an amount  equal to the par
value of shares owned by them (and to the consideration for which shares without
par value  were issued)  for debts  owing to  employees of  the corporation  for
services  performed for such corporation, but  not exceeding six months' service
in any one case. The  liability imposed by the  predecessor to this statute  was
interpreted  in a trial court decision to extend to the original issue price for
shares, rather than  the stated par  value. Although affirmed  by the  Wisconsin
Supreme  Court, the case offers  no precedential value due  to the fact that the
decision was affirmed by an equally divided court. The DGCL and the IBCA do  not
contain comparable provisions.
 
    DISTRIBUTIONS.    The IBCA  and  the WBCL  both  provide that  the  board of
directors may authorize and the corporation may make, subject to any restriction
by the articles of incorporation, distributions to its shareowners unless  after
such  distribution the corporation  would not be  able to pay  its debts as they
become due or its total assets after the distribution would be less than the sum
of its  total  liabilities,  plus  the  amount that  would  be  needed,  if  the
corporation were to be dissolved at the time of the distribution, to satisfy the
preferential  rights upon  dissolution of shareowners  whose preferential rights
are superior to those receiving the distribution.
 
    The  DGCL  provides  that,  subject  to  any  restrictions  contained  in  a
corporation's  certificate of incorporation,  the directors may  declare and pay
dividends either (i) out of the corporation's surplus, or (ii) if there shall be
no surplus, out of the  corporation's net profits for  the fiscal year in  which
the   dividend  is  declared  and/or  the  preceding  fiscal  year,  unless  the
corporation's capital is diminished by depreciation  to an amount less than  the
aggregate  capital represented by the corporation's issued and outstanding stock
having a distribution preference.
 
    SPECIAL MEETINGS OF SHAREOWNERS.  Under  the DGCL, IBCA and WBCL, a  special
meeting  of shareowners may be called by the board of directors or by any person
authorized by the certificate or articles  of incorporation or bylaws to call  a
special  meeting. The IBCA and WBCL further provide for the calling of a special
meeting pursuant to a written demand of the holders of not less than 10% of  the
votes entitled to be cast at such a meeting.
 
    DISSENTERS'  RIGHTS.  The DGCL, IBCA and  WBCL each entitle shareowners of a
corporation to dissent from and obtain fair value for their shares in the  event
of  certain corporate  actions. Subject  to certain  exceptions, limitations and
conditions, shareowners of corporations incorporated in these states may dissent
from a plan of merger. The IBCA and WBCL also both provide that shareowners  may
dissent from a statutory share exchange or a sale of all or substantially all of
the assets of the
 
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corporation.  The IBCA  also provides that  dissenters' rights  are available to
shareholders in the event of any amendment to the articles of incorporation that
materially and adversely  affects the  rights or preferences  of the  dissenting
shareholders'  shares in certain specified ways. The DGCL, IBCA and WBCL provide
that a corporation may create  additional dissenters' rights in its  certificate
or  articles  of incorporation.  The IBCA  and WBCL  also allow  corporations to
create additional dissenters' rights in their bylaws or by board resolution.
 
    The DGCL and WBCL both provide that dissenters' rights are not available  to
holders  of shares  listed on  a national securities  exchange or  quoted on the
Nasdaq National Market. In addition,  the DGCL provides that dissenters'  rights
are  not available  to holders of  shares that are  held of record  by more than
2,000 holders.  The DGCL  provides that  such shares  do not  carry  dissenters'
rights  unless the  holders thereof are  required to accept  in consideration of
their shares anything other than listed securities or cash in lieu of fractional
shares. The  WBCL provides  that such  shares do  not carry  dissenters'  rights
unless  the articles of incorporation provide  otherwise or except in a Business
Combination (as defined under the WBCL and described below under  "Anti-Takeover
Statutes").
 
    DIRECTOR AND OFFICER DISCRETION.  The WBCL provides that, in discharging his
or  her duties to the corporation and in  determining what he or she believes to
be in the  best interests  of the  corporation, a  director or  officer may,  in
addition  to considering the effects of  any action on shareowners, consider (i)
the effects  of  the  action  on  employees,  suppliers  and  customers  of  the
corporation,  (ii) the  effects of  the action on  the communities  in which the
corporation operates and (iii)  any other factors that  the director or  officer
considers  pertinent. The IBCA contains comparable provisions. The IBCA provides
that, in discharging the duties of the position of director, a director may,  in
considering the best interests of the corporation, consider the interests of the
corporation's employees, customers, suppliers, and creditors, the economy of the
state  and nation, community  and societal considerations,  and the long-term as
well as short-term interests of  the corporation and its shareholders  including
the  possibility  that  these interests  may  be  best served  by  the continued
independence of the corporation. Delaware judicial doctrine allows directors  to
consider similar factors.
 
ANTI-TAKEOVER STATUTES
 
    Wisconsin  law regulates a broad range  of "business combinations" between a
Wisconsin corporation and an "interested  stockholder." Wisconsin law defines  a
"business  combination" to include a merger or a share exchange, sale of assets,
issuance of  stock  or  rights  to purchase  stock  and  certain  related  party
transactions.   An  "interested  stockholder"   is  defined  as   a  person  who
beneficially owns, directly or indirectly,  10% of the outstanding voting  stock
of  a corporation  or who is  an affiliate  or associate of  the corporation and
beneficially owned 10%  of the voting  stock within the  last three years.  With
certain  exceptions, Wisconsin  law prohibits a  corporation from  engaging in a
business combination with an interested stockholder for a period of three  years
following  the date on which the person became an interested stockholder, unless
the board of directors approved the  business combination or the acquisition  of
the  stock  prior  to the  interested  stockholder's stock  acquisition  date. A
corporation may engage in a business combination with an interested  stockholder
after  the  third  anniversary  of  the acquisition  date  provided  any  of the
following is satisfied:  (i) the  board of  directors approved  the purchase  of
stock  by the interested stockholder prior to the interested stockholder's stock
acquisition date, (ii) the business combination is approved by a majority of the
outstanding voting  stock not  owned by  the interested  stockholder, (iii)  the
consideration  to be received  by shareowners meets  certain requirements of the
statute with respect to form and amount or (iv) the business combination is of a
type specifically excluded from the coverage of the statute.
 
    Section 180.1150 of the WBCL  provides that in particular circumstances  the
voting  of  shares  of a  Wisconsin  "issuing public  corporation"  (a Wisconsin
corporation which has at least 100  Wisconsin resident shareowners, 500 or  more
shareowners  of record and total assets exceeding $1 million) held by any person
in excess of 20% of the voting power is limited to 10% of the full voting  power
of  such excess shares. Full voting power may be restored under Section 180.1150
if a majority of the voting power of shares represented at a meeting,  including
those  held  by  the party  seeking  restoration,  are voted  in  favor  of such
restoration.
 
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    In addition, the WBCL sets forth certain fair price provisions which  govern
mergers  and share exchanges with, or sales  of substantially all of a Wisconsin
issuing public corporation's  assets to,  a 10% shareowner,  mandating that  any
such  transaction meet one  of two requirements. First,  the transaction must be
approved  by  80%   of  all  shareowners   and  two-thirds  of   "disinterested"
shareowners, which generally exclude the 10% shareowner. Second, the corporation
must pay a statutory fair price, which is intended to insure that shareowners in
the  second step  merger, share  exchange or  asset sale  receive at  least what
shareowners received in the first step.
 
    Further, the WBCL requires shareowner  approval for certain transactions  in
the context of a tender offer or similar action for an amount in excess of 5% of
a  Wisconsin  corporation's  stock.  Shareowner  approval  is  required  for the
acquisition of more than 5% of the  corporation's stock at a price above  market
value,  unless  the corporation  makes  an equal  offer  to acquire  all shares.
Shareowner approval is  also required  for the sale  or option  of assets  which
amount  to  at  least 10%  of  the market  value  of the  corporation,  but this
requirement does  not apply  if the  corporation meets  certain minimum  outside
director standards.
 
    Section  203  of  the  DGCL (the  "Delaware  Business  Combination Statute")
applies to certain business combinations involving a corporation and certain  of
its   stockholders.  The  Delaware  Business   Combination  Statute  prevents  a
corporation from engaging in  any "business combination"  (defined to include  a
variety  of transactions, including the sale of assets, mergers and most related
party transactions) with  an "interested  stockholder" (defined  generally as  a
person  owning 15%  or more of  the corporation's outstanding  voting stock) for
three  years  following   the  date  such   stockholder  became  an   interested
stockholder, unless (i) before such person became an interested stockholder, the
board  of directors of the corporation  approved the business combination or the
transaction  in   which  the   interested  stockholder   became  an   interested
stockholder,  or (ii) upon consummation of the transaction which resulted in the
stockholder becoming an interested stockholder, the interested stockholder owned
at least 85% of the voting stock of the corporation outstanding at the time  the
transaction  commenced (excluding stock held by  directors who are also officers
of the corporation  and by  certain employee  stock ownership  plans), or  (iii)
following the transaction in which such person became an interested stockholder,
the  business  combination  is  approved  by  the  board  of  directors  of  the
corporation and authorized at a meeting of stockholders by the affirmative  vote
of  the holders of two-thirds of the outstanding voting stock of the corporation
not owned by the interested stockholder.
 
                                      119
<PAGE>
               UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION
 
    The  following  unaudited  pro  forma  financial  information  combines  the
historical consolidated balance sheets and statements of income of WPLH, IES and
IPC, including  their  respective  Subsidiaries,  after  giving  effect  to  the
Mergers.  The  historical  data  for  WPLH have  been  adjusted  to  reflect the
restatement  of  such  data  to  account  for  certain  discontinued  operations
discussed in the notes hereto. The unaudited pro forma combined balance sheet at
March  31, 1996 gives effect to the Mergers as if they had occurred at March 31,
1996. The unaudited  pro forma  combined statements of  income for  each of  the
three years in the period ended December 31, 1995, the three-month periods ended
March  31, 1996 and 1995, and the  twelve-month period ended March 31, 1996 give
effect to  the  Mergers as  if  they had  occurred  at January  1,  1993.  These
statements are prepared on the basis of accounting for the Mergers as pooling of
interests  and are based on  the assumptions set forth  in the notes thereto. In
addition, the  pro forma  financial  information does  not  give effect  to  the
expected  synergies or the costs  to be incurred to  achieve such synergies. The
pro forma financial information, however, does reflect the transaction costs  to
effect the Mergers.
 
    The  following pro forma  financial information has  been prepared from, and
should be  read  in  conjunction with,  the  historical  consolidated  financial
statements  and  related notes  thereto of  WPLH, IES  and IPC,  incorporated by
reference herein. The following information is not necessarily indicative of the
financial position or operating results that would have occurred had the Mergers
been consummated on the date, or at the beginning of the periods, for which  the
Mergers  are  being given  effect  nor is  it  necessarily indicative  of future
operating results  or financial  position. In  addition, due  to the  effect  of
weather  on sales and  other factors which are  characteristic of public utility
operations, financial results for the  three-month periods ended March 31,  1996
and 1995 are not necessarily indicative of trends for any twelve-month period.
 
                                      120
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
                   UNAUDITED PRO FORMA COMBINED BALANCE SHEET
 
                                 MARCH 31, 1996
                                 (IN THOUSANDS)
 
ASSETS
<TABLE>
<CAPTION>
                                                                                             WPLH            IES            IPC
                                                                                         (AS REPORTED)  (AS REPORTED)  (AS REPORTED)
                                                                                         -------------  -------------  -------------
<S>                                                                                      <C>            <C>            <C>
UTILITY PLANT
  Electric.............................................................................   $ 1,674,322    $ 1,909,500    $   836,863
  Gas..................................................................................       218,973        166,248         63,344
  Other................................................................................       163,576        106,504        --
                                                                                         -------------  -------------  -------------
      Total............................................................................     2,056,871      2,182,252        900,207
  Accumulated provision for depreciation...............................................       908,603        973,304        409,051
  Construction work in progress........................................................        42,848         65,862          3,945
  Nuclear fuel -- net..................................................................        14,976         34,915        --
                                                                                         -------------  -------------  -------------
      Net utility plant................................................................     1,206,092      1,309,725        495,101
OTHER PROPERTY, PLANT AND EQUIPMENT -- NET AND INVESTMENTS.............................       148,100        250,703          1,231
CURRENT ASSETS
  Cash and cash equivalents............................................................         7,935         10,435          1,218
  Accounts receivable -- net...........................................................        81,797         54,838         29,559
  Fossil fuel inventories, at average cost.............................................        12,285         12,313         11,938
  Materials and supplies, at average cost..............................................        20,904         25,164          5,762
  Prepayments and other................................................................        24,163         40,224         14,165
                                                                                         -------------  -------------  -------------
      Total current assets.............................................................       147,084        142,974         62,642
EXTERNAL DECOMMISSIONING FUND..........................................................        82,523         49,543        --
DEFERRED CHARGES AND OTHER.............................................................       254,875        233,999         71,133
                                                                                         -------------  -------------  -------------
      TOTAL ASSETS.....................................................................   $ 1,838,674    $ 1,986,944    $   630,107
                                                                                         -------------  -------------  -------------
                                                                                         -------------  -------------  -------------
 
<CAPTION>
                                                                                          PRO FORMA   PRO FORMA
                                                                                         ADJUSTMENTS   COMBINED
                                                                                         -----------  ----------
<S>                                                                                      <C>          <C>
UTILITY PLANT
  Electric.............................................................................      --       $4,420,685
  Gas..................................................................................      --          448,565
  Other................................................................................      --          270,080
                                                                                         -----------  ----------
      Total............................................................................      --        5,139,330
  Accumulated provision for depreciation...............................................      --        2,290,958
  Construction work in progress........................................................      --          112,655
  Nuclear fuel -- net..................................................................      --           49,891
                                                                                         -----------  ----------
      Net utility plant................................................................      --        3,010,918
OTHER PROPERTY, PLANT AND EQUIPMENT -- NET AND INVESTMENTS.............................      --          400,034
CURRENT ASSETS
  Cash and cash equivalents............................................................      --           19,588
  Accounts receivable -- net...........................................................      --          166,194
  Fossil fuel inventories, at average cost.............................................      --           36,536
  Materials and supplies, at average cost..............................................      --           51,830
  Prepayments and other................................................................      --           78,552
                                                                                         -----------  ----------
      Total current assets.............................................................      --          352,700
EXTERNAL DECOMMISSIONING FUND..........................................................      --          132,066
DEFERRED CHARGES AND OTHER.............................................................      --          560,007
                                                                                         -----------  ----------
      TOTAL ASSETS.....................................................................   $  --       $4,455,725
                                                                                         -----------  ----------
                                                                                         -----------  ----------
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      121
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
             UNAUDITED PRO FORMA COMBINED BALANCE SHEET (CONTINUED)
 
                                 MARCH 31, 1996
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>
                                                                                          WPLH            IES            IPC
                                                                                      (AS REPORTED)  (AS REPORTED)  (AS REPORTED)
                                                                                      -------------  -------------  -------------
<S>                                                                                   <C>            <C>            <C>
LIABILITIES AND EQUITY
CAPITALIZATION
  Common Stock Equity:
    Common stock (Note 1)...........................................................   $       308    $   396,230    $    33,475
    Other stockholders' equity (Note 1).............................................       613,320        219,590        168,238
                                                                                      -------------  -------------  -------------
      Total common stock equity.....................................................       613,628        615,820        201,713
  Preferred stock not mandatorily redeemable........................................        59,963         18,320         10,819
  Preferred stock mandatory sinking fund............................................       --             --              24,062
  Long-term debt -- net.............................................................       428,347        600,677        188,899
                                                                                      -------------  -------------  -------------
      Total capitalization..........................................................     1,101,938      1,234,817        425,493
CURRENT LIABILITIES
  Current maturities, sinking funds, and capital lease obligations..................         1,406         30,234        --
  Commercial paper, notes payable and other.........................................        57,896         92,000         23,150
  Variable rate demand bonds........................................................        56,975        --             --
  Accounts payable and accruals.....................................................        93,463         68,656         14,145
  Taxes accrued.....................................................................        24,103         69,294         20,801
  Other accrued liabilities.........................................................        41,455         69,370         14,714
                                                                                      -------------  -------------  -------------
      Total current liabilities.....................................................       275,298        329,554         72,810
OTHER LIABILITIES
  Deferred income taxes.............................................................       245,153        256,066         96,663
  Deferred investment tax credits...................................................        38,364         36,454         17,784
  Accrued environmental remediation costs...........................................        76,763         43,680          6,834
  Capital lease obligations.........................................................       --              20,135        --
  Other liabilities and deferred credits............................................       101,158         66,238         10,523
                                                                                      -------------  -------------  -------------
      Total other liabilities.......................................................       461,438        422,573        131,804
                                                                                      -------------  -------------  -------------
    TOTAL CAPITALIZATION AND LIABILITIES............................................   $ 1,838,674    $ 1,986,944    $   630,107
                                                                                      -------------  -------------  -------------
                                                                                      -------------  -------------  -------------
 
<CAPTION>
                                                                                       PRO FORMA   PRO FORMA
                                                                                      ADJUSTMENTS   COMBINED
                                                                                      -----------  ----------
<S>                                                                                   <C>          <C>
LIABILITIES AND EQUITY
CAPITALIZATION
  Common Stock Equity:
    Common stock (Note 1)...........................................................   $(429,299)  $      714
    Other stockholders' equity (Note 1).............................................     421,039    1,422,187
                                                                                      -----------  ----------
      Total common stock equity.....................................................      (8,260)   1,422,901
  Preferred stock not mandatorily redeemable........................................      --           89,102
  Preferred stock mandatory sinking fund............................................      --           24,062
  Long-term debt -- net.............................................................      --        1,217,923
                                                                                      -----------  ----------
      Total capitalization..........................................................      (8,260)   2,753,988
CURRENT LIABILITIES
  Current maturities, sinking funds, and capital lease obligations..................      --           31,640
  Commercial paper, notes payable and other.........................................      --          173,046
  Variable rate demand bonds........................................................      --           56,975
  Accounts payable and accruals.....................................................      --          176,264
  Taxes accrued.....................................................................      --          114,198
  Other accrued liabilities.........................................................      14,000      139,539
                                                                                      -----------  ----------
      Total current liabilities.....................................................      14,000      691,662
OTHER LIABILITIES
  Deferred income taxes.............................................................      (5,740)     592,142
  Deferred investment tax credits...................................................      --           92,602
  Accrued environmental remediation costs...........................................      --          127,277
  Capital lease obligations.........................................................      --           20,135
  Other liabilities and deferred credits............................................      --          177,919
                                                                                      -----------  ----------
      Total other liabilities.......................................................      (5,740)   1,010,075
                                                                                      -----------  ----------
    TOTAL CAPITALIZATION AND LIABILITIES............................................   $  --       $4,455,725
                                                                                      -----------  ----------
                                                                                      -----------  ----------
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      122
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                       THREE MONTHS ENDED MARCH 31, 1996
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                                WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                            (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS    COMBINED
                                            -------------  -------------  -------------  -------------  -----------
<S>                                         <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric................................   $   148,500    $   125,368     $  65,915      $  --         $ 339,783
  Gas.....................................        71,741         90,024        21,134         --           182,899
  Other...................................        40,636         27,805        --             --            68,441
                                            -------------  -------------  -------------  -------------  -----------
    Total operating revenues..............       260,877        243,197        87,049         --           591,123
Operating Expenses
  Electric production fuels...............        28,604         20,292        14,774         --            63,670
  Purchased power.........................        15,344         14,469        14,193         --            44,006
  Cost of gas sold........................        45,364         67,437        11,473         --           124,274
  Other operation.........................        76,565         52,525        11,712         --           140,802
  Maintenance.............................         8,551         10,833         3,693         --            23,077
  Depreciation and amortization...........        23,116         27,384         7,577         --            58,077
  Taxes other than income taxes...........         9,171         13,262         4,550         --            26,983
                                            -------------  -------------  -------------  -------------  -----------
    Total operating expenses..............       206,715        206,202        67,972         --           480,889
                                            -------------  -------------  -------------  -------------  -----------
Operating Income..........................        54,162         36,995        19,077         --           110,234
Other Income (expense)
  Allowance for equity funds used during
   construction...........................           529        --             --             --               529
  Other income and deductions -- net......         3,950          1,677           812         --             6,439
                                            -------------  -------------  -------------  -------------  -----------
    Total other income (expense)..........         4,479          1,677           812         --             6,968
Interest Charges..........................         8,674         12,216         4,077         --            24,967
                                            -------------  -------------  -------------  -------------  -----------
Income from continuing operations before
 income taxes and preferred dividends.....        49,967         26,456        15,812         --            92,235
Income Taxes..............................        17,459         12,132         6,271         --            35,862
Preferred dividends of subsidiaries (Note
 2).......................................           828            229           615         --             1,672
                                            -------------  -------------  -------------  -------------  -----------
Income from Continuing Operations (Notes 3
 and 6)...................................   $    31,680    $    14,095     $   8,926      $  --         $  54,701
                                            -------------  -------------  -------------  -------------  -----------
                                            -------------  -------------  -------------  -------------  -----------
Average Common Shares Outstanding (Note
 1).......................................        30,774         29,645         9,564          1,348        71,331
Earnings per share of Common Stock from
 continuing operations....................      $1.03          $0.48         $0.93           $--          $0.77
                                               -----          -----          -----          -----         -----
                                               -----          -----          -----          -----         -----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      123
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                       THREE MONTHS ENDED MARCH 31, 1995
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                                WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                            (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS    COMBINED
                                            -------------  -------------  -------------  -------------  -----------
<S>                                         <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric................................   $   131,151    $   116,577     $  63,803      $  --         $ 311,531
  Gas.....................................        55,207         64,982        18,962         --           139,151
  Other...................................        29,516         24,833        --             --            54,349
                                            -------------  -------------  -------------  -------------  -----------
    Total operating revenues..............       215,874        206,392        82,765         --           505,031
Operating Expenses
  Electric production fuels...............        29,713         19,443        16,840         --            65,996
  Purchased power.........................         7,148         16,314        12,102         --            35,564
  Cost of gas sold........................        33,882         49,289         9,957         --            93,128
  Other operation.........................        59,991         48,090        12,031         --           120,112
  Maintenance.............................         9,832         12,163         3,440         --            25,435
  Depreciation and amortization...........        21,284         25,538         7,226         --            54,048
  Taxes other than income taxes...........         9,323         13,440         4,505         --            27,268
                                            -------------  -------------  -------------  -------------  -----------
    Total operating expenses..............       171,173        184,277        66,101         --           421,551
                                            -------------  -------------  -------------  -------------  -----------
Operating Income..........................        44,701         22,115        16,664         --            83,480
Other Income (expense)
  Allowance for equity funds used during
   construction...........................           271            282        --             --               553
  Other income and deductions -- net......            35            360           270         --               665
                                            -------------  -------------  -------------  -------------  -----------
    Total other income (expense)..........           306            642           270         --             1,218
Interest Charges..........................        10,157         11,136         4,217         --            25,510
                                            -------------  -------------  -------------  -------------  -----------
Income from continuing operations before
 income taxes and preferred dividends.....        34,850         11,621        12,717         --            59,188
Income Taxes..............................        13,963          4,652         4,960         --            23,575
Preferred dividends of subsidiaries (Note
 2).......................................           828            229           614         --             1,671
                                            -------------  -------------  -------------  -------------  -----------
Income from Continuing Operations (Notes 3
 and 6)...................................   $    20,059    $     6,740     $   7,143      $  --         $  33,942
                                            -------------  -------------  -------------  -------------  -----------
                                            -------------  -------------  -------------  -------------  -----------
Average Common Shares Outstanding (Note
 1).......................................        30,774         28,889         9,564          1,341        70,568
Earnings per share of Common Stock from
 continuing operations....................      $0.65          $0.23         $0.75           $--          $0.48
                                               -----          -----          -----          -----         -----
                                               -----          -----          -----          -----         -----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      124
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                       TWELVE MONTHS ENDED MARCH 31, 1996
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                               WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                           (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                           -------------  -------------  -------------  -------------  ------------
<S>                                        <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric...............................   $   563,672    $   569,262    $   276,986     $  --        $  1,409,920
  Gas....................................       155,703        215,381         45,840        --             416,924
  Other..................................       132,883        103,173        --             --             236,056
                                           -------------  -------------  -------------  -------------  ------------
    Total operating revenues.............       852,258        887,816        322,826        --           2,062,900
Operating Expenses.......................
  Electric production fuels..............       115,380         97,105         60,099        --             272,584
  Purchased power........................        52,210         65,029         59,656        --             176,895
  Cost of gas sold.......................        95,483        159,864         27,404        --             282,751
  Other operation........................       267,371        205,822         45,398        --             518,591
  Maintenance............................        40,762         44,763         15,134        --             100,659
  Depreciation and amortization..........        88,151         99,803         29,911        --             217,865
  Taxes other than income taxes..........        34,036         48,836         16,034        --              98,906
                                           -------------  -------------  -------------  -------------  ------------
    Total operating expenses.............       693,393        721,222        253,636        --           1,668,251
Operating Income.........................       158,865        166,594         69,190        --             394,649
                                           -------------  -------------  -------------  -------------  ------------
Other Income (expense)...................
  Allowance for equity funds used during
   construction..........................         1,684            104        --             --               1,788
  Other income and deductions -- net.....         7,018          4,489         (2,330)       --               9,177
                                           -------------  -------------  -------------  -------------  ------------
    Total other income (expense).........         8,702          4,593         (2,330)       --              10,965
Interest Charges.........................        41,414         48,772         16,655        --             106,841
                                           -------------  -------------  -------------  -------------  ------------
Income from continuing operations before
 income taxes and preferred dividends....       126,153        122,415         50,205        --             298,773
Income Taxes.............................        39,604         49,970         20,764        --             110,338
Preferred dividends of subsidiaries (Note
 2)......................................         3,310            914          2,459        --               6,683
                                           -------------  -------------  -------------  -------------  ------------
Income from Continuing Operations (Notes
 3 and 6)................................   $    83,239    $    71,531    $    26,982     $  --        $    181,752
                                           -------------  -------------  -------------  -------------  ------------
                                           -------------  -------------  -------------  -------------  ------------
Average Common Shares Outstanding (Note
 1)......................................        30,774         29,391          9,564         1,346          71,075
Earnings per share of Common Stock from
 continuing operations...................      $2.70          $2.43         $2.82           $--           $2.56
                                              -----          -----          -----          -----           ----
                                              -----          -----          -----          -----           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      125
<PAGE>
                         INTERSTATE ENERGY CORPORATION
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
                          YEAR ENDED DECEMBER 31, 1995
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                               WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                           (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                           -------------  -------------  -------------  -------------  ------------
<S>                                        <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric...............................   $   546,324    $   560,471    $   274,873     $  --        $  1,381,668
  Gas....................................       139,165        190,339         43,669        --             373,173
  Other..................................       121,766        100,200        --             --             221,966
                                           -------------  -------------  -------------        -----    ------------
    Total operating revenues.............       807,255        851,010        318,542        --           1,976,807
Operating Expenses
  Electric production fuels..............       116,488         96,256         62,164        --             274,908
  Purchased power........................        44,015         66,874         57,566        --             168,455
  Cost of gas sold.......................        84,002        141,716         25,888        --             251,606
  Other operation........................       250,796        201,390         45,717        --             497,903
  Maintenance............................        42,043         46,093         14,881        --             103,017
  Depreciation and amortization..........        86,319         97,958         29,560        --             213,837
  Taxes other than income
   taxes.................................        34,188         49,011         15,990        --              99,189
                                           -------------  -------------  -------------        -----    ------------
    Total operating expenses.............       657,851        699,298        251,766        --           1,608,915
                                           -------------  -------------  -------------        -----    ------------
Operating Income.........................       149,404        151,712         66,776        --             367,892
Other Income (Expense)
  Allowance for equity funds used during
   construction..........................         1,425            386        --             --               1,811
  Other income and deductions -- net.....         3,103          3,170         (2,872)       --               3,401
                                           -------------  -------------  -------------        -----    ------------
    Total other income
     (expense)...........................         4,528          3,556         (2,872)       --               5,212
Interest Charges.........................        42,896         47,689         16,795        --             107,380
                                           -------------  -------------  -------------        -----    ------------
Income from continuing operations before
 income taxes and preferred dividends....       111,036        107,579         47,109        --             265,724
Income Taxes.............................        36,108         42,489         19,453        --              98,050
Preferred dividends of subsidiaries (Note
 2)......................................         3,310            914          2,458        --               6,682
                                           -------------  -------------  -------------        -----    ------------
Income from Continuing Operations (Notes
 3 and 6)................................   $    71,618    $    64,176    $    25,198     $  --        $    160,992
                                           -------------  -------------  -------------        -----    ------------
                                           -------------  -------------  -------------        -----    ------------
Average Common Shares Outstanding (Note
 1)......................................        30,774         29,202          9,564         1,344          70,884
Earnings per share of Common Stock from
 continuing operations...................      $2.33          $2.20         $2.63       $   --            $2.27
                                              -----          -----          -----         ------           ----
                                              -----          -----          -----         ------           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      126
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
 
                          YEAR ENDED DECEMBER 31, 1994
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                               WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                           (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                           -------------  -------------  -------------  -------------  ------------
<S>                                        <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric...............................   $   531,747    $   537,327    $   261,730     $  --        $  1,330,804
  Gas....................................       151,931        165,569         45,920        --             363,420
  Other..................................       112,039         82,968        --             --             195,007
                                           -------------  -------------  -------------        -----    ------------
    Total operating revenues.............       795,717        785,864        307,650        --           1,889,231
Operating Expenses
  Electric production fuels..............       123,469         85,952         61,384        --             270,805
  Purchased power........................        37,913         68,794         58,339        --             165,046
  Cost of gas sold.......................       100,942        120,795         30,905        --             252,642
  Other operation........................       246,212        176,863         51,917        --             474,992
  Maintenance............................        41,227         52,841         17,160        --             111,228
  Depreciation and amortization..........        80,351         86,378         28,212        --             194,941
  Taxes other than income
   taxes.................................        33,788         46,308         16,298        --              96,394
                                           -------------  -------------  -------------        -----    ------------
    Total operating expenses.............       663,902        637,931        264,215        --           1,566,048
                                           -------------  -------------  -------------        -----    ------------
Operating Income.........................       131,815        147,933         43,435        --             323,183
Other Income (Expense)
  Allowance for equity funds used during
   construction..........................         3,009          2,299            166        --               5,474
  Other income and deductions -- net.....         7,610          3,472          3,100        --              14,182
                                           -------------  -------------  -------------        -----    ------------
    Total other income
     (expense)...........................        10,619          5,771          3,266        --              19,656
Interest Charges.........................        36,657         44,399         16,845        --              97,901
                                           -------------  -------------  -------------        -----    ------------
Income from continuing operations before
 income taxes and preferred dividends....       105,777        109,305         29,856        --             244,938
Income Taxes.............................        36,043         41,573          9,189        --              86,805
Preferred dividends of subsidiaries (Note
 2)......................................         3,310            914          2,454        --               6,678
                                           -------------  -------------  -------------        -----    ------------
Income from Continuing Operations (Notes
 3 and 6)................................   $    66,424    $    66,818    $    18,213     $  --        $    151,455
                                           -------------  -------------  -------------        -----    ------------
                                           -------------  -------------  -------------        -----    ------------
Average Common Shares Outstanding (Note
 1)......................................        30,671         28,560          9,479         1,329          70,039
Earnings per share of Common Stock from
 continuing operations...................      $2.17          $2.34         $1.92       $   --            $2.16
                                              -----          -----          -----         ------           ----
                                              -----          -----          -----         ------           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      127
<PAGE>
                         INTERSTATE ENERGY CORPORATION
 
               UNAUDITED PRO FORMA COMBINED STATEMENTS OF INCOME
 
                          YEAR ENDED DECEMBER 31, 1993
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                               WPLH            IES            IPC         PRO FORMA     PRO FORMA
                                           (AS REPORTED)  (AS REPORTED)  (AS REPORTED)   ADJUSTMENTS     COMBINED
                                           -------------  -------------  -------------  -------------  ------------
<S>                                        <C>            <C>            <C>            <C>            <C>
Operating Revenues
  Electric...............................   $   503,187    $   550,521    $   255,759     $  --        $  1,309,467
  Gas....................................       137,270        181,923         53,709        --             372,902
  Other..................................        98,147         68,822        --             --             166,969
                                           -------------  -------------  -------------        -----    ------------
    Total operating revenues.............       738,604        801,266        309,468        --           1,849,338
Operating Expenses
  Electric production fuels..............       123,919         87,702         64,059        --             275,680
  Purchased power........................        28,574         93,449         53,936        --             175,959
  Cost of gas sold.......................        90,505        135,830         38,309        --             264,644
  Other operation........................       221,840        162,642         48,567        --             433,049
  Maintenance............................        44,763         48,913         16,771        --             110,447
  Depreciation and amortization..........        68,680         77,012         26,955        --             172,647
  Taxes other than income taxes..........        32,379         44,449         17,080        --              93,908
                                           -------------  -------------  -------------        -----    ------------
    Total operating expenses.............       610,660        649,997        265,677        --           1,526,334
                                           -------------  -------------  -------------        -----    ------------
Operating Income.........................       127,944        151,269         43,791        --             323,004
Other Income (Expense)
  Allowance for equity funds used during
   construction..........................         2,978            824             68        --               3,870
  Other income and deductions net........          (633)        (2,908)         1,209        --              (2,332)
                                           -------------  -------------  -------------        -----    ------------
    Total other income (expense).........         2,345         (2,084)         1,277        --               1,538
Interest Charges.........................        37,020         43,292         16,617        --              96,929
                                           -------------  -------------  -------------        -----    ------------
Income from continuing operations before
 income taxes and preferred dividends....        93,269        105,893         28,451        --             227,613
Income Taxes.............................        25,656         37,041          9,464        --              72,161
Preferred dividends of subsidiaries (Note
 2)......................................         3,928            914          2,861        --               7,703
                                           -------------  -------------  -------------        -----    ------------
Income from Continuing Operations (Notes
 3 and 6)................................   $    63,685    $    67,938    $    16,126     $  --        $    147,749
                                           -------------  -------------  -------------        -----    ------------
                                           -------------  -------------  -------------        -----    ------------
Average Common Shares Outstanding (Note
 1)......................................        29,681         27,764          9,316         1,303          68,064
Earnings per share of Common Stock from
 continuing operations...................      $2.15          $2.45         $1.73       $   --            $2.17
                                              -----          -----          -----         ------           ----
                                              -----          -----          -----         ------           ----
</TABLE>
 
  See accompanying Notes to Unaudited Pro Forma Combined Financial Statements
 
                                      128
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                         COMBINED FINANCIAL STATEMENTS
 
1.   The pro forma combined financial  statements reflect the conversion of each
    share of IES  Common Stock (no  par value) outstanding  into 1.01 shares  of
    WPLH  Common Stock ($.01 par value) and  the conversion of each share of IPC
    Common Stock ($3.50 par  value) into 1.11  of a share  of WPLH Common  Stock
    ($.01  par value), and the  continuation of each share  of WPLH Common Stock
    ($.01 par value) outstanding as one share of Interstate Energy Common Stock,
    as provided in  the Merger  Agreement. The  pro forma  adjustment to  common
    stock  equity restates the common  stock account to equal  par value for all
    shares to be issued  ($.01 par value per  share of Interstate Energy  Common
    Stock)  and reclassifies the  excess to other  stockholders' equity. The pro
    forma combined statements of income are  presented as if the companies  were
    combined  on January  1, 1993.  The pro  forma combined  balance sheet gives
    effect to the Mergers as if they occurred at March 31, 1996.
 
    The number of shares of common stock used for calculating per share  amounts
    is based on the exchange ratios shown below.
 
        AVERAGE NUMBER OF SHARES OUTSTANDING FOR THE TWELVE MONTHS ENDED
 
<TABLE>
<CAPTION>
                   EXCHANGE       AS REPORTED   PRO FORMA   AS REPORTED   PRO FORMA   AS REPORTED   PRO FORMA
                     RATIO          3/31/96      3/31/96     12/31/95     12/31/95     12/31/94     12/31/94
               -----------------  -----------  -----------  -----------  -----------  -----------  -----------
                                                                 (IN THOUSANDS)
<S>            <C>                <C>          <C>          <C>          <C>          <C>          <C>
IES..........           1.01          29,391       29,685       29,202       29,494       28,560       28,846
IPC..........           1.11           9,564       10,616        9,564       10,616        9,479       10,522
WPLH.........            N/A          30,774       30,774       30,774       30,774       30,671       30,671
</TABLE>
 
<TABLE>
<CAPTION>
                                         EXCHANGE       AS REPORTED   PRO FORMA
                                           RATIO         12/31/93     12/31/93
                                     -----------------  -----------  -----------
                                                             (IN THOUSANDS)
<S>                                  <C>                <C>          <C>          <C>          <C>
IES................................           1.01          27,764       28,042
IPC................................           1.11           9,316       10,341
WPLH...............................            N/A          29,681       29,681
</TABLE>
 
        AVERAGE NUMBER OF SHARES OUTSTANDING FOR THE THREE MONTHS ENDED
 
<TABLE>
<CAPTION>
                                         EXCHANGE       AS REPORTED   PRO FORMA   AS REPORTED   PRO FORMA
                                           RATIO          3/31/96      3/31/96      3/31/95      3/31/95
                                     -----------------  -----------  -----------  -----------  -----------
                                                                          (IN THOUSANDS)
<S>                                  <C>                <C>          <C>          <C>          <C>
IES................................           1.01          29,645       29,941       28,889       29,178
IPC................................           1.11           9,564       10,616        9,564       10,616
WPLH...............................            N/A          30,774       30,774       30,774       30,774
</TABLE>
 
2.  The IPC Preferred Stock has been reclassified in the pro forma statements as
    preferred stock of subsidiary companies and deducted in the determination of
    income  from  continuing  operations  which  reflects  the  holding  company
    structure of the entity formed through the Mergers.
 
3.  Nonrecurring items affecting WPLH's 1994 performance included the impact  of
    early  retirement and severance programs and the reversal of a coal contract
    penalty assessed by the Wisconsin Commission which was charged to income  in
    1989.  The net  after-tax impact  of these  items on  income from continuing
    operations for  the year  ended December  31, 1994  was a  decrease of  $8.3
    million  related to the early retirement and severance programs offset by an
    increase of $4.9 million related to the coal contract penalty reversal.
 
                                      129
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                   COMBINED FINANCIAL STATEMENTS (CONTINUED)
 
    IPC's income from  continuing operations includes  expenses associated  with
    the environmental investigation and remediation costs of former manufactured
    gas  plants. Operating expenses  for the twelve months  ended March 31, 1996
    and for  the years  ended December  31,  1995, 1994  and 1993  include  $0.2
    million,  $0.3  million, $0.8  million and  $3.5 million,  respectively, for
    these costs. Other operating expenses for the twelve months ended March  31,
    1996  and for the year ended December 31, 1995 also include $0.8 million and
    $0.7 million, respectively, of legal  fees related to coal tar  remediation,
    compared with $1.0 million and $0.3 million for the years ended December 31,
    1994  and 1993, respectively. For the twelve months ended March 31, 1996 and
    for the years  ended December 31,  1995, 1994 and  1993, $0.4 million,  $0.6
    million,  $0.7  million and  $0.6  million, respectively,  of  the foregoing
    expenses were recovered in rates.
 
    Nonrecurring items affecting IES's income from continuing operations for the
    year ended December  31, 1993 include  various gains and  losses related  to
    sales  of  assets and  property  valuation adjustments  associated  with its
    nonregulated businesses. The net after-tax  impact of these items on  income
    from  continuing  operations for  the  year ended  December  31, 1993  was a
    decrease of $2.0 million.
 
4.   The  allocation between  WPLH,  IES and  IPC  and their  customers  of  the
    estimated  costs  savings  of  approximately  $749  million  over  ten years
    resulting from  the Mergers,  net  of the  costs  incurred to  achieve  such
    savings,  will be subject  to regulatory review  and approval. Costs arising
    from the proposed Mergers are currently estimated to be approximately  $78.4
    million  (including transaction costs  of $11.5 million  related to fees for
    financial  advisors  and  $2.5  million  related  to  fees  for   attorneys,
    accountants,  consultants, filings  and printing).  None of  these estimated
    cost savings, or the costs to  achieve such savings, have been reflected  in
    the pro forma combined financial statements. The transaction costs have been
    reflected  in  the pro  forma  balance sheet  at  March 31,  1996  such that
    shareowner equity has  been reduced  by $8.26  million, accrued  liabilities
    have  been increased by $14.0 million,  and deferred taxes were decreased by
    $5.74 million.
 
5.    Intercompany   transactions  (including  purchased   and  exchange   power
    transactions)  between WPLH, IES  and IPC during  the periods presented were
    included in  the determination  of regulated  rates and  were not  material.
    Accordingly,   no  pro  forma  adjustments   were  made  to  eliminate  such
    transactions.
 
6.  The financial statements of WPLH reflect the discontinuance of operations of
    its  utility  energy  and  marketing   consulting  business  in  1995.   The
    discontinuance  of this business resulted in  a pre-tax loss of $7.7 million
    ($11.0 million net of the applicable income tax expenses) in 1995. Operating
    revenues, operating expenses, other income and expense and income taxes  for
    the  discontinued  operations  for  the  time  periods  presented  have been
    excluded from income from continuing  operations. Interest expense has  been
    adjusted   for  the  amounts  associated  with  direct  obligations  of  the
    discontinued operations.
 
                                      130
<PAGE>
                         INTERSTATE ENERGY CORPORATION
                          NOTES TO UNAUDITED PRO FORMA
                   COMBINED FINANCIAL STATEMENTS (CONTINUED)
 
    Operating revenues, related losses, and income tax benefits associated  with
    the discontinued operations for the indicated time periods were as follows:
 
<TABLE>
<CAPTION>
                                                       TWELVE MONTHS
                                                           ENDED           YEAR ENDED DECEMBER 31,
                                                         MARCH 31,     -------------------------------
                                                            1996         1995       1994       1993
                                                       --------------  ---------  ---------  ---------
                                                                   (DOLLARS IN THOUSANDS)
<S>                                                    <C>             <C>        <C>        <C>
Operating revenues...................................    $   15,969    $  24,979  $  34,798  $  33,340
                                                       --------------  ---------  ---------  ---------
                                                       --------------  ---------  ---------  ---------
Loss from discontinued operations before tax
 benefit.............................................    $    2,990    $   3,663  $   1,806  $   1,761
Income tax benefit...................................         1,184        1,451        632        599
                                                       --------------  ---------  ---------  ---------
Loss from discontinued operations....................    $    1,806    $   2,212  $   1,174  $   1,162
                                                       --------------  ---------  ---------  ---------
                                                       --------------  ---------  ---------  ---------
</TABLE>
 
7.    Accounting  principles have  been  consistently applied  in  the financial
    statement presentations for WPLH, IES and  IPC with one exception. IPC  does
    not  include unbilled electric and gas  revenues in its calculation of total
    revenues. The utility subsidiaries of WPLH and IES accrue unbilled revenues.
    The impact of this difference  in accounting principles among the  companies
    does  not  have  a  material  impact on  the  unaudited  pro  forma combined
    financial statements as presented and, accordingly, no adjustments have been
    made to conform accounting principles.
 
                                      131
<PAGE>
               SELECTED INFORMATION CONCERNING WPLH, IES AND IPC
 
BUSINESS OF WPLH
 
    WPLH,  incorporated under the laws of the State of Wisconsin in 1981, is the
holding company for WP&L and its  utility-related subsidiaries and for HDC,  the
parent  corporation for WPLH's non-utility businesses.  WP&L is a public utility
engaged principally in generating, purchasing, distributing and selling electric
energy in  portions of  southern  and central  Wisconsin. WP&L  also  purchases,
distributes,  transports  and  sells natural  gas  in  parts of  such  areas and
supplies water in two  communities. A wholly-owned  subsidiary of WP&L  supplies
electric,  gas and water service principally in Winnebago County, Illinois. WP&L
provides retail  electric  service to  approximately  377,000 customers  in  663
cities, villages and towns, and wholesale service to 27 municipal utilities, one
privately-owned  utility, three  rural electric  cooperatives and  the Wisconsin
Public Power, Inc. system,  which provides retail  service to nine  communities.
WP&L  owns 20,969 miles of electric  transmission and distribution lines and 362
substations located adjacent  to the  communities served.  WP&L provides  retail
natural  gas service to approximately 146,000  customers in 239 cities, villages
and towns.
 
    HDC and its principal  subsidiaries are engaged  in business development  in
three major areas: (i) environmental engineering and consulting, (ii) affordable
housing and (iii) energy services.
 
    The  principal executive  office of WPLH  is located at  222 West Washington
Avenue, Madison, Wisconsin 53703, telephone number (608) 252-3311.
 
BUSINESS OF IES
 
    IES, incorporated under the laws of the State of Iowa in 1986, is a  holding
company  for Utilities  and Diversified,  the parent  company for  most of IES's
non-utility businesses.  Utilities  is a  public  utility primarily  engaged  in
providing  electric energy, natural gas and, to a limited extent, steam used for
heating and  industrial purposes  in Iowa.  Utilities serves  more than  333,000
electric   customers  and  174,000  natural  gas  customers  in  more  than  550
communities across Iowa  and provides  wholesale electrical service  to 30  Iowa
municipal utilities.
 
    Diversified  is a  holding company  that is  engaged in  various non-utility
operations, including  energy  production  and  marketing,  railroad  and  other
transportation   services,  and  local  real   estate  development  through  its
wholly-owned  subsidiaries.  IES  Energy   Inc.  develops  stand-by   production
facilities  for large users of electricity, markets natural gas and steam to end
users, and purchases, explores for, develops and produces crude oil and  natural
gas.  IES Transportation Inc.  provides short-line rail  freight service between
Cedar Rapids and Iowa City, Iowa, provides barge terminal and hauling service on
the Mississippi  River,  and provides  transloading  and storage  services.  IES
Investments,  Inc. pursues  real estate  and economic  development activities in
Utilities' service territory,  owns resort properties,  and holds certain  other
passive equity investments.
 
    The principal executive office of IES and Utilities is located at IES Tower,
200  First  Street  S.E.,  Cedar  Rapids,  Iowa  52401,  telephone  number (319)
398-4411.
 
BUSINESS OF IPC
 
    IPC is an operating  public utility incorporated in  1925 under the laws  of
the  State  of  Delaware.  IPC services  162,000  retail  electric  customers in
portions of  25 counties  in  northern and  northeastern  Iowa, portions  of  22
counties  in southern  Minnesota and portions  of four  counties in northwestern
Illinois. IPC  also  serves 48,600  natural  gas customers  in  39  communities,
including  Albert Lea, Minnesota; Clinton, Mason  City and Clear Lake, Iowa; and
Fulton and Savanna, Illinois. In addition, IPC engages in the transportation  of
natural gas within Iowa, Minnesota and in interstate commerce.
 
    The  principal  executive office  of  IPC is  located  at 1000  Main Street,
Dubuque, Iowa 52001, telephone number (319) 582-5421.
 
                                      132
<PAGE>
CERTAIN BUSINESS RELATIONSHIPS BETWEEN WPLH, IES AND IPC
 
    In the  normal course  of business,  WP&L, Utilities  and IPC  buy and  sell
electric  power from and to each  other in arm's-length transactions pursuant to
filed  rate  schedules.  In  addition,  from  time  to  time,  a  subsidiary  of
Diversified has provided WP&L with barge service across the Mississippi River to
facilitate  the delivery of  coal to WP&L's generating  facilities. IPC also has
contracted with a subsidiary of HDC for certain energy brokerage services.
 
                    INTERSTATE ENERGY FOLLOWING THE MERGERS
 
    No later than  the Effective Time,  subject to approval  of the Name  Change
Amendment  at the WPLH Meeting, WPLH will  change its name to "Interstate Energy
Corporation." Interstate Energy will  be the parent  of IPC or  New IPC, as  the
case  may  be,  and  the  operating  subsidiaries  of  both  WPLH  and  IES. The
headquarters of Interstate  Energy will  be in Madison,  Wisconsin. The  utility
subsidiaries  of  Interstate  Energy  will  serve  more  than  870,000  electric
customers and  360,000 natural  gas customers,  and its  service territory  will
include  portions of  Wisconsin, Iowa, Illinois  and Minnesota.  The business of
Interstate Energy  will  consist of  owning  utilities and  various  non-utility
subsidiaries. WPLH, IES and IPC recognize that the divestiture of their existing
gas operations and certain non-utility operations is a possibility under the new
registered  holding company structure, but are  seeking approval from the SEC to
maintain such businesses. See "Regulatory Matters."
 
MANAGEMENT OF INTERSTATE ENERGY
 
    Pursuant to  the Merger  Agreement, at  the Effective  Time, the  Interstate
Energy  Board will  consist of  fifteen members,  six members  of which  will be
designated by WPLH, including Mr. Davis, six members of which will be designated
by IES, including Mr. Liu, and three members of which will be designated by IPC,
including Mr.  Stoppelmoor.  It  is anticipated  that  simultaneously  with  the
Mergers,  all but six of  the WPLH directors then in  office will resign and the
remaining WPLH directors will increase the  size of the Interstate Energy  Board
to fifteen and appoint the six persons designated by the IES Board and the three
persons  designated by the IPC Board to  fill the nine resulting vacancies. WPLH
and IES will each  designate two directors and  IPC will designate one  director
for each of Classes I and II of the Interstate Energy Board. Class III directors
will  consist of Messrs. Liu,  Davis and Stoppelmoor, as  well as one additional
designee of each of WPLH and IES. To date, WPLH, IES and IPC have not determined
which individuals, in addition  to Messrs. Liu, Davis  and Stoppelmoor, will  be
designated  to serve as directors of Interstate Energy as of the Effective Time.
Each designee shall  serve for  a term  equal to  the remaining  balance of  the
three-year term of the class of directors in which such designee shall serve. At
each  annual  shareowners'  meeting  after the  Effective  Time,  the  number of
directors equal to the number of the class whose term expires at the time of the
meeting shall be elected for a term of three years. See "The Merger Agreement --
Interstate Energy Board of Directors."
 
    At the Effective Time,  Mr. Liu will be  Chairman of Interstate Energy,  Mr.
Davis  will be President  and Chief Executive Officer  of Interstate Energy, Mr.
Stoppelmoor will be  Vice Chairman of  Interstate Energy and  Mr. Chase will  be
President of IPC or New IPC, as the case may be. Each of Mr. Liu, Mr. Davis, Mr.
Stoppelmoor  and Mr.  Chase will  have an  employment agreement  with Interstate
Energy or its subsidiaries following the Mergers. See "The Mergers -- Employment
Agreements." At  the Effective  Time, Mr.  Ahearn will  be President  and  Chief
Operating  Officer  of  the  holding company  for  the  non-utility  business of
Interstate Energy.
 
OPERATIONS
 
    After the Mergers, WP&L, Utilities or New Utilities, as the case may be, and
IPC or New IPC, as the case  may be, will operate as the principal  subsidiaries
of  Interstate Energy.  The headquarters of  the three utilities  will remain in
their current locations.
 
    Except for the transfer of WP&L's water utility business in Wisconsin to New
Utilities and New IPC in the event  that the IPC Reincorporation Merger and  the
Utilities  Reincorporation Merger are effected,  the utility operations of WP&L,
Utilities   and    IPC   will    continue   and    will   be    unaffected    by
 
                                      133
<PAGE>
consummation  of the Mergers. The Wisconsin  water utility business of WP&L will
be transferred to New  Utilities and New IPC  immediately after consummation  of
the  Mergers in the event that the  IPC Reincorporation Merger and the Utilities
Reincorporation Merger are  effected. Upon  receipt of  the necessary  approvals
from  the FERC and applicable state regulators and on or following the Effective
Time, WP&L, Utilities or New Utilities, as the case may be, and IPC or New  IPC,
as  the  case  may be,  expect  to enter  into  a power  purchase  agreement and
agreements providing for the integrated operation (including joint dispatch)  of
their  systems and expect to become parties to a coordination agreement, whereby
costs of generating capacity and transmission will be shared. The integration of
the WP&L, Utilities or New Utilities, as the case may be, and IPC or New IPC, as
the case  may be,  generating  capacity should  increase  the ability  of  these
companies to meet demands for electricity within the territories each serves. It
is  also anticipated  that a  single administrative  and support  system will be
established following the Mergers.
 
    The non-utility operations of WPLH are presently conducted through HDC,  and
most  of  the  non-utility operations  of  IES are  presently  conducted through
Diversified. Following the Mergers, it  is anticipated that HDC and  Diversified
will  be  combined  into one  entity  to  manage the  diversified  operations of
Interstate Energy.
 
DIVIDENDS
 
    It is anticipated  that Interstate  Energy will retain  WPLH's then  current
common share dividend. Based on the dividend paid for the first quarter of 1996,
WPLH's annualized dividend rate is currently $1.97 per share, IES currently pays
$2.10  per share annually and IPC's annual  dividend rate is currently $2.08 per
share. However, no assurance  can be given  that such dividend  rate will be  in
effect  or will  remain unchanged, and  Interstate Energy reserves  the right to
increase or decrease its dividend  as may be required by  law or contract or  as
may  be determined  by the  Interstate Energy  Board, in  its discretion,  to be
advisable. Declaration and timing of dividends on Interstate Energy Common Stock
will be a business decision to be made by the Interstate Energy Board from  time
to  time  based  upon  the  results of  operations  and  financial  condition of
Interstate Energy and its subsidiaries and such other business considerations as
the Interstate Energy  Board considers  relevant in  accordance with  applicable
laws.  For a description of certain  restrictions on Interstate Energy's ability
to pay dividends  on the  Interstate Energy  Common Stock,  see "Description  of
Interstate Energy Capital Stock."
 
                                    EXPERTS
 
    The  consolidated financial statements and schedules of WPLH at December 31,
1995 and 1994 and for each of the three years in the period ending December  31,
1995  incorporated by  reference in  this Joint  Proxy Statement/Prospectus have
been  audited  by  Arthur  Andersen  LLP,  independent  public  accountants,  as
indicated  in their  reports with  respect thereto,  and are  included herein in
reliance upon the authority of said  firm as experts in accounting and  auditing
in giving said reports.
 
    The  consolidated financial statements  and schedule of  IES at December 31,
1995 and 1994 and for each of the three years in the period ending December  31,
1995  incorporated by  reference in  this Joint  Proxy Statement/Prospectus have
been  audited  by  Arthur  Andersen  LLP,  independent  public  accountants,  as
indicated  in their  reports with  respect thereto,  and are  included herein in
reliance upon the authority of said  firm as experts in accounting and  auditing
in giving said reports.
 
    The financial statements and the related financial statement schedule of IPC
at  December 31, 1995  and 1994 and  for each of  the three years  in the period
ended December 31, 1995 incorporated in this Joint Proxy Statement/Prospectus by
reference from IPC's Annual Report on Form 10-K for the year ended December  31,
1995 have been audited by Deloitte & Touche LLP, independent auditors, as stated
in  their reports, which are incorporated herein  by reference, and have been so
incorporated in  reliance  upon  the  reports of  such  firm  given  upon  their
authority as experts in accounting and auditing.
 
                                      134
<PAGE>
                                 LEGAL MATTERS
 
    Foley  & Lardner, Milwaukee,  Wisconsin, will pass upon  the legality of the
shares of Interstate  Energy Common Stock  and the shares  of New IPC  Preferred
Stock, if any, to be issued in connection with the Mergers.
 
                              SHAREOWNER PROPOSALS
 
    In  order to  be eligible  to be  considered for  inclusion in  WPLH's proxy
materials relating to the WPLH annual shareowner meeting in 1997, any shareowner
proposal intended  to be  presented at  that  meeting must  be received  at  the
principal office of WPLH on or before November 20, 1996.
 
    In  order  to be  eligible to  be  considered for  inclusion in  IES's proxy
materials relating to the IES annual shareowner meeting in 1997, any  shareowner
proposal  intended  to be  presented at  that  meeting must  be received  at the
principal office of IES on or before on or before November 20, 1996.
 
    In order  to be  eligible to  be  considered for  inclusion in  IPC's  proxy
materials  relating to the IPC annual shareowner meeting in 1997, any shareowner
proposal intended  to be  presented at  that  meeting must  be received  at  the
principal office of IPC on or before on or before November 20, 1996.
 
                                      135
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
                           ELECTION OF WPLH DIRECTORS
 
    Three  directors are to be  elected at the WPLH  Meeting. Rockne G. Flowers,
Katharine C. Lyall and Henry  C. Prange are nominees to  hold office for a  term
expiring  at  the 1999  Annual Meeting  of  Shareowners of  WPLH or  until their
successors have been duly elected and qualified.
 
    The proxies solicited may be voted  for a substitute nominee or nominees  in
the  event that any of the nominees shall be unable to serve, or for good reason
will not serve, a contingency not now anticipated.
 
    Brief biographies of the director nominees and continuing directors  follow.
These  biographies include their  age (as of  December 31, 1995),  an account of
their business  experience, and  the names  of publicly-held  and certain  other
corporations  of which they  are also directors.  Except as otherwise indicated,
each nominee and  continuing director  has been engaged  in his  or her  present
occupation for at least the past five years.
 
NOMINEES
 
    THE  WPLH BOARD RECOMMENDS THE FOLLOWING  NOMINEES FOR ELECTION AS DIRECTORS
AND URGES EACH  SHAREOWNER TO  VOTE "FOR" ALL  NOMINEES. SHARES  OF WPLH  COMMON
STOCK  REPRESENTED  BY EXECUTED  BUT UNMARKED  PROXIES WILL  BE VOTED  "FOR" ALL
NOMINEES.
 
<TABLE>
<S>                    <C>
ROCKNE G. FLOWERS      Principal Occupation: President and Director of Nelson Industries,
                       Inc. (a muffler, filter, industrial silencer, and active sound and
(Photo)                vibration control technology and manufacturing firm), Stoughton,
                       Wisconsin.
                       Age: 64
                       Served as director since 1981
                       Annual Meeting at which nominated term of office will expire: 1999
 
OTHER INFORMATION:  Mr. Flowers has served as  a director of WP&L since 1994. He  previously
served as a director of WP&L from 1979 to 1990. Mr. Flowers is also a director of RMT, Inc.,
a  subsidiary of HDC; Digisonix, Inc.;  American Family Mutual Insurance Company; Janesville
Sand and Gravel Company; M&I Madison Bank; Meriter Health Services, Inc.; Meriter  Hospital;
and   the  Wisconsin  History  Foundation.  He  is  also  a  member  of  the  University  of
Wisconsin-Madison School of Business Board of Visitors.
 
KATHARINE C. LYALL     Principal Occupation: President, University of Wisconsin System,
                       Madison, Wisconsin.
(Photo)                Age: 54
                       Served as director from 1986 to 1990 and since 1994
                       Annual Meeting at which nominated term of office will expire: 1999
 
OTHER INFORMATION:  Ms. Lyall has served as President of the University of Wisconsin  System
since April 1992. Prior to becoming President, she served as Executive Vice President of the
University  of Wisconsin System. Ms. Lyall has served  as a director of WP&L since 1986. She
also serves on the  Board of Directors  of the Kemper National  Insurance Companies and  the
Carnegie  Foundation  for the  Advancement of  Teaching. She  is  a member  of a  variety of
professional and community organizations, including  the American Economic Association;  the
Association  of American  Universities (currently serving  on the  executive committee); the
Wisconsin Academy  of Sciences,  Arts and  Letters; the  American Red  Cross (Dane  County);
Competitive  Wisconsin,  Inc.;  and Forward  Wisconsin.  In addition  to  her administrative
position, she is a professor of economics at the University of Wisconsin-Madison.
</TABLE>
 
                                      136
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
<TABLE>
<S>                    <C>
HENRY C. PRANGE        Principal Occupation: Retired Chairman of the Board, H. C. Prange
                       Company (retail stores), Green Bay, Wisconsin.
(Photo)                Age: 68
                       Served as director since 1986
                       Annual Meeting at which nominated term of office will expire: 1999
 
OTHER INFORMATION:  Mr. Prange has served as a director of WP&L since 1965.
 
CONTINUING DIRECTORS
 
L. DAVID CARLEY        Principal Occupation: Consultant to institutions and associations in
                       higher education and health delivery; financial advisor to small
(Photo)                businesses.
                       Age: 67
                       Served as director from 1986 to 1990 and since 1994
                       Annual Meeting at which current term of office will expire: 1998
 
OTHER INFORMATION:  Mr. Carley has served as a director of WP&L from 1975 to 1977, and again
since 1983. He is also a trustee of the Kennedy Presidential Library, and is the Chairman of
the Board of Alliance Therapies Inc., a health rehabilitation firm.
 
ERROLL B. DAVIS, JR.   Principal Occupation: President and Chief Executive Officer of WPLH;
                       President and Chief Executive Officer of WP&L; Chairman of the Board
(Photo)                of HDC.
                       Age: 51
                       Served as director since 1982
                       Annual Meeting at which current term of office will expire: 1997
 
OTHER INFORMATION:  Mr. Davis was elected President of WPLH in January 1990, and was elected
President and Chief Executive  Officer of WPLH effective  July 1, 1990. He  has served as  a
director  of WP&L since 1984. Mr. Davis joined WP&L in August 1978 and was elected President
in July 1987. He was elected to his current position with WP&L in August 1988. Mr. Davis was
elected Chairman of the Board of HDC effective July 1, 1990. He is a director of the  Edison
Electric  Institute, the  Association of Edison  Illuminating Companies,  Amoco Oil Company,
Competitive Wisconsin, Inc., Electric Power Research Institute, PPG Industries, Inc., Sentry
Insurance Company (a mutual company), and the Wisconsin Utilities Association. Mr. Davis  is
also  a director and immediate past chair  of the Wisconsin Association of Manufacturers and
Commerce and a director and vice chair of Forward Wisconsin.
</TABLE>
 
                                      137
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
<TABLE>
<S>                    <C>
DONALD R. HALDEMAN     Principal Occupation: Executive Vice President and Chief Executive
                       Officer, Rural Insurance Companies (a mutual group), Madison,
(Photo)                Wisconsin.
                       Age: 59
                       Served as director from 1986 to 1990 and since 1994
                       Annual Meeting at which current term of office will expire: 1998
 
OTHER INFORMATION:  Mr. Haldeman has served as a director of WP&L since 1985. Mr. Haldeman
is also a director of Competitive Wisconsin, Inc., and a member of the Board of Directors of
the Natural Resources Foundation of Wisconsin, Inc.
 
ARNOLD M. NEMIROW      Principal Occupation: President and Chief Executive Officer, Bowater,
                       Inc. (a pulp and paper manufacturer), Greenville, South Carolina.
(Photo)                Age: 52
                       Served as director since 1991
                       Annual Meeting at which current term of office will expire: 1998
 
OTHER INFORMATION:  Mr. Nemirow served as President, Chief Executive Officer and Director of
Wausau Paper Mills Company, a pulp and paper manufacturer, from 1990 until joining  Bowater,
Inc.,  in September 1994. Mr. Nemirow  has served as a director of  WP&L since 1994. He is a
member of the New York Bar.
 
MILTON E. NESHEK       Principal Occupation: President, Chief Executive Officer and Director
                       of the law firm of Godfrey, Neshek, Worth, and Leibsle, S.C.,
(Photo)                Elkhorn, Wisconsin, and General Counsel, Assistant Secretary and
                       Manager, New Market Development, Kikkoman Foods, Inc. (a food
                       products manufacturer), Walworth, Wisconsin.
                       Age: 65
                       Served as director since 1986
                       Annual Meeting at which current term of office will expire: 1997
OTHER INFORMATION:  Mr. Neshek has served as a director of WP&L since 1984. Mr. Neshek is  a
director  of HPI and Capital Square Financial Corporation, a subsidiary of HDC. He is also a
director of Kikkoman  Foods, Inc.; Midwest  U.S.-Japan Association; Regional  Transportation
Authority  (for southeast Wisconsin); and Wisconsin-Chiba,  Inc. Mr. Neshek was the Chairman
of the  Governor's Commission  on  University of  Wisconsin  System Compensation  from  1991
through  1995 and  is a  former member  of the  University of  Wisconsin Accountability Task
Force. He is a fellow in  the American College of Probate  Counsel. Mr. Neshek is active  in
the  Walworth County Bar Association and  the State Bar of Wisconsin  and is a member of the
Wisconsin Sesquicentennial Commission.
</TABLE>
 
                                      138
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
<TABLE>
<S>                    <C>
JUDITH D. PYLE         Principal  Occupation:  Vice  Chair  and  Senior  Vice  President  of
                       Corporate  Marketing of  Rayovac Corporation (a  battery and lighting
(Photo)                products manufacturer), Madison, Wisconsin.
                       Age: 52
                       Served as a director since 1992
                       Annual Meeting at which current term of office will expire: 1998
 
OTHER INFORMATION:  Ms. Pyle has served as a director of WP&L since 1994. Ms. Pyle is also a
director of Rayovac  Corporation, Firstar  Corporation, and Oshkosh  B'Gosh. She  is also  a
member  of the Board of Visitors  at the University of Wisconsin  School of Business and the
School of Family Resources and Consumer Sciences. Further, Ms. Pyle is a member of Boards of
Directors of the  United Way Foundation,  Greater Madison Chamber  of Commerce, Madison  Art
Center,  and Wisconsin  Taxpayers Alliance, and  is a  trustee of the  White House Endowment
Fund.
 
CAROL T. TOUSSAINT     Principal Occupation: Consultant
                       Age: 66
(Photo)                Served as director from 1986 to 1990 and since 1994
                       Annual Meeting at which current term of office will expire: 1997
 
OTHER INFORMATION:  Mrs.  Toussaint has served as  a director of WP&L  since 1976. She is  a
Senior  Associate of Hayes Briscoe,  a national fund development firm.  She also works as an
independent consultant to nonprofit organizations  and operates a lecture program  business.
She  is a member of the  President's Advisory Council on the  Arts of the Kennedy Center for
the Performing  Arts,  and  serves on  the  Board  of Governors  of  the  Madison  Community
Foundation and as Vice Chair of the Madison Rotary Foundation. Mrs. Toussaint also serves as
a  director of the Evjue  Foundation, the Madison Civic  Center Foundation and the Wisconsin
History Foundation. At the University of Wisconsin-Madison, she serves as a director of  the
Research  Park, the School of Business Dean's Advisory Board and the Foundation's Council on
Women's Giving, and as a director of the  Alumni Association and convener of its Cabinet  99
Women's Initiative.
</TABLE>
 
                      APPOINTMENT OF INDEPENDENT AUDITORS
 
    The  Audit  Committee  of the  Board  of  Directors of  WPLH  recommends the
reappointment  of  Arthur  Andersen  LLP,  independent  public  accountants,  as
auditors  to examine  the consolidated  financial statements  of WPLH  for 1996.
Arthur Andersen LLP served as auditors for WPLH in 1995.
 
    A representative of Arthur Andersen LLP  will be present at the meeting  and
available to make a statement or to respond to questions, as appropriate.
 
    THE  WPLH BOARD RECOMMENDS A VOTE "FOR" THE REAPPOINTMENT OF ARTHUR ANDERSEN
LLP. SHARES OF WPLH  COMMON STOCK REPRESENTED BY  EXECUTED BUT UNMARKED  PROXIES
WILL BE VOTED "FOR" SUCH REAPPOINTMENT.
 
                   MEETINGS AND COMMITTEES OF THE WPLH BOARD
 
    The   WPLH  Board  has  standing  Audit,  Compensation  and  Personnel,  and
Nominating Committees.  A  description  of  the duties  of  each  committee  and
meetings held during 1995 follows.
 
                                      139
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
AUDIT COMMITTEE
 
    As of January 1, 1995, the committee consisted of L. Aspin, L. D. Carley, R.
G.  Flowers, D. R. Haldeman,  H. F. Scheig, and K.  C. Lyall (Chair). Mr. Scheig
retired as a director effective May 17,  1995. Mr. Aspin passed away on May  21,
1995.  The committee held two meetings in  1995. The committee recommends to the
shareowners the  independent auditors  to be  elected; reviews  the reports  and
comments  of the  independent auditors;  reviews the  activities and  reports of
WPLH's internal audit  staff; and, in  response to the  reports and comments  of
both  the independent  auditors and  internal auditors,  recommends to  the WPLH
Board any action which the Audit Committee considers appropriate.
 
COMPENSATION AND PERSONNEL COMMITTEE
 
    As of January  1, 1995,  the committee  consisted of  A. M.  Nemirow, M.  E.
Neshek  (Chair), H. C. Prange, J. D. Pyle, and C. T. Toussaint. On May 17, 1995,
Mr. Nemirow became Chair  of the Committee. The  committee held six meetings  in
1995.  The committee sets executive compensation policy; reviews the performance
of and approves salaries  for officers and  certain other management  personnel;
reviews  and recommends to the WPLH Board new or changed employee benefit plans;
reviews major provisions of negotiated employment contracts, if any; and reviews
human resource development programs.
 
NOMINATING COMMITTEE
 
    As of January 1, 1995, the committee  consisted of L. Aspin, R. G.  Flowers,
K.  C. Lyall, A. M. Nemirow (Chair), H. C. Prange, and J. D. Pyle. As of May 17,
1995, Mr. L. D. Carley was added to the Nominating Committee and was elected  as
Chair. Mr. Aspin passed away on May 21, 1995. The committee held two meetings in
1995.  The committee's  responsibilities include  making recommendations  to the
WPLH  Board  for   nominees  for  election   to  the  WPLH   Board.  In   making
recommendations  of  nominees for  election to  the  WPLH Board,  the Nominating
Committee will  consider nominees  recommended  by shareowners.  Any  shareowner
wishing  to make  a recommendation should  write the Chief  Executive Officer of
WPLH, who will forward all recommendations to the Nominating Committee.
 
    The WPLH Board held eleven meetings  during 1995. No director attended  less
than  76%  of the  aggregate  number of  meetings of  the  WPLH Board  and board
committees on which they served.
 
COMPENSATION OF DIRECTORS
 
    No fees are paid  to directors who  are officers of WPLH  and/or any of  its
subsidiaries  (presently Mr. Davis). Nonmanagement directors, each of whom serve
on the Boards of WPLH, WP&L, and HDC, receive an annual retainer of $32,800  for
service  on all  three boards.  Travel expenses  are paid  for each  meeting day
attended. All nonmanagement directors also  receive a 25% matching  contribution
in WPLH Common Stock for limited optional cash purchases, up to $10,000, of WPLH
Common  Stock through the  WPLH DRIP. Matching contributions  of $2,500 each for
calendar year  1995 were  made for  the  following directors:  L. Aspin,  L.  D.
Carley, R. G. Flowers, D. R. Haldeman, K. C. Lyall, A. M. Nemirow, M. E. Neshek,
H. C. Prange, J. D. Pyle, H. F. Scheig and C. T. Toussaint.
 
    DIRECTOR'S   CHARITABLE  AWARD  PROGRAM  --   WPLH  maintains  a  Director's
Charitable Award  Program  for  the  nonmanagement members  of  the  WPLH  Board
beginning  after  three years  of  service. The  purpose  of the  program  is to
recognize  the  interest  of  WPLH  and  its  directors  in  supporting   worthy
institutions,  and enhance WPLH's director benefit  program so that WPLH is able
to continue to attract  and retain directors of  the highest caliber. Under  the
program,  when a  director dies,  WPLH will  donate a  total of  $500,000 to one
qualified charitable organization, or divide that amount among a maximum of four
qualified charitable  organizations, selected  by the  individual director.  The
individual   director  derives  no  financial  benefit  from  the  program.  All
deductions for charitable contributions are taken by WPLH, and the donations are
funded by WPLH through life insurance policies on the
 
                                      140
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
directors. Over the life of the program, all costs of donations and premiums  on
the life insurance policies, including a return of WPLH's cost of funds, will be
recovered  through life insurance  proceeds on the  directors. The program, over
its life, will not result in any material cost to WPLH.
 
    DIRECTOR'S  LIFE  INSURANCE  PROGRAM   --  WPLH  maintains  a   split-dollar
Director's  Life Insurance  Program for  nonemployee directors,  beginning after
three years of service,  which provides a maximum  death benefit of $500,000  to
each  eligible  director.  Under  the  split-dollar  arrangement,  directors are
provided a death benefit only and do not have any interest in the cash value  of
the  policies. The Life Insurance Program is  structured to pay a portion of the
total death benefit  to WPLH to  reimburse WPLH  for all costs  of the  program,
including a return on its funds. The Life Insurance Program, over its life, will
not result in any material cost to WPLH.
 
                         OWNERSHIP OF VOTING SECURITIES
 
    Listed  in the following table are the  shares of WPLH Common Stock owned by
the executive  officers  listed  in  the  Summary  Compensation  Table  and  all
directors  of  WPLH, as  well as  the number  of shares  owned by  directors and
officers as a group as  of June 1, 1996. The  table also sets forth each  person
known by WPLH to beneficially own as of June 1, 1996 five percent or more of the
outstanding shares of WPLH Common Stock.
 
<TABLE>
<CAPTION>
                                                                                         SHARES         PERCENT OF
NAME OF BENEFICIAL OWNER                                                           BENEFICIALLY OWNED     CLASS
- ---------------------------------------------------------------------------------  ------------------  ------------
<S>                                                                                <C>                 <C>
Executive (1)
  Lance W. Ahearn................................................................        22,997(2)          *
  A. J. (Nino) Amato.............................................................         2,389(3)          *
  William D. Harvey..............................................................         7,393(3)          *
  Eliot G. Protsch...............................................................         8,344(3)          *
Director Nominees
  Rockne G. Flowers..............................................................         7,863             *
  Katharine C. Lyall.............................................................         4,859             *
  Henry C. Prange................................................................         9,792(3)          *
Continuing Directors
  L. David Carley................................................................         3,623             *
  Erroll B. Davis, Jr............................................................        10,486(3)(4)       *
  Donald R. Haldeman.............................................................         3,510             *
  Arnold M. Nemirow..............................................................         6,814             *
  Milton E. Neshek...............................................................        10,656             *
  Judith D. Pyle.................................................................         4,592             *
  Carol T. Toussaint.............................................................         8,947             *
All Executives and Directors as a Group
 27 people, including those listed above.........................................       129,364             *
Other Beneficial Owners (5)
  IES............................................................................     6,123,944              16.6%
  IPC............................................................................     6,123,944              16.6%
</TABLE>
 
- ------------------------
 *  Less than one percent of the total outstanding shares of WPLH Common Stock.
 
(1) Stock ownership of Mr. Davis is shown with continuing directors.
 
(2)  Prior to  April 1,  1996, Mr.  Ahearn owned  5 shares  of HDC  common stock
    subject to the  terms of  a Restricted Stock  Agreement with  HDC and  WPLH.
    Pursuant  to such agreement, Mr. Ahearn exchanged one-third of his shares of
    HDC common stock for WPLH Common Stock on April 1, 1996. Based on the  terms
    of the agreement and the most recent available appraisal of HDC, pursuant to
    which the exchange ratio is calculated, Mr. Ahearn received 21,672 shares of
    WPLH  Common Stock in exchange for one-third of his HDC shares. Mr. Ahearn's
    beneficial ownership
 
                                      141
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
    reflected in the  table above includes  the shares of  WPLH Common Stock  he
    received  pursuant to such an exchange. It is currently anticipated that HDC
    will also repurchase an  additional 1.80 HDC shares  from Mr. Ahearn at  the
    most recent per share appraised value.
 
(3)  Included in the beneficially owned  shares shown are the following indirect
    ownership interests with shared voting  and investment powers: Mr. Amato  --
    880;  Mr. Harvey -- 1,558;  Mr. Protsch -- 394; Mr.  Davis -- 4,602; and Mr.
    Prange -- 248.
 
(4) Mr. Davis  has been awarded  1.67 shares of  HDC common stock  subject to  a
    Restricted Stock Agreement with HDC and WPLH.
 
(5)  By reason of the Stock Option Agreements, each of IES and IPC may be deemed
    to have sole voting and dispositive power with respect to the shares  listed
    above  which  are  subject  to  their  respective  Options  from  WPLH  and,
    accordingly, each of IES and  IPC may be deemed  to beneficially own all  of
    such  shares (assuming exercise  of its Option and  the nontriggering of the
    other party's right to exercise its Option for WPLH Common Stock).  However,
    each  of IES  and IPC  expressly disclaim  any beneficial  ownership of such
    shares because the  Options are exercisable  only in certain  circumstances.
    See "The Stock Option Agreements."
 
                       COMPENSATION OF EXECUTIVE OFFICERS
 
    The  following Summary Compensation Table  sets forth the total compensation
paid by WPLH and its subsidiaries  for all services rendered during 1995,  1994,
and  1993  to  the  Chief  Executive Officer  and  the  four  other  most highly
compensated executive officers of  WPLH or its  subsidiaries who perform  policy
making functions for WPLH.
 
                           SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
                                                                              LONG-TERM COMPENSATION
                                                                            --------------------------
                                                                                      AWARDS
                                                                            --------------------------
                                            ANNUAL COMPENSATION                            SECURITIES
                                 -----------------------------------------   RESTRICTED    UNDERLYING
      NAME AND                                             OTHER ANNUAL         STOCK       OPTIONS/        ALL OTHER
 PRINCIPAL POSITION     YEAR     SALARY (1)     BONUS    COMPENSATION (2)    AWARDS (3)     SARS (4)    COMPENSATION (5)
- --------------------  ---------  -----------  ---------  -----------------  -------------  -----------  -----------------
<S>                   <C>        <C>          <C>        <C>                <C>            <C>          <C>
Erroll B. Davis, Jr.       1995   $ 426,038   $ 125,496      $  18,963       $         0       13,100       $  61,513
 President and CEO         1994     426,038     128,232         14,958           272,000            0          57,723
                           1993     427,616     115,796         10,262                 0            0          55,674
William D. Harvey          1995     203,846      47,340          5,746                 0        4,700          23,534
 Senior Vice               1994     193,654      56,080          5,203                 0            0          22,632
 President-                1993     168,962      42,104          4,152                 0            0          24,003
 WP&L
Eliot G. Protsch           1995     200,000      47,520          4,169                 0        4,700          20,178
 Senior Vice               1994     190,000      56,080          3,930                 0            0          18,346
 President-                1993     154,549      42,104          3,194                 0            0          15,371
 WP&L
Lance W. Ahearn            1995     195,000      34,125          3,814                 0            0          29,663
 President and             1994     186,533      33,576              0                 0            0          30,811
 CEO-HDC                   1993     170,500      84,609              0                 0            0           3,570
Anthony J. Amato           1995     156,804      40,046          5,144                 0        3,650          18,059
 Senior Vice               1994     152,885      43,138          5,328                 0            0          17,021
 President-                1993     140,769      33,240          4,181                 0            0          17,842
 WP&L
</TABLE>
 
- ------------------------
(1) Includes vacation days sold back to WPLH.
 
(2)  For all except Mr. Davis, amounts  for 1995 consist of income tax gross-ups
    for reverse  split-dollar life  insurance. For  Mr. Davis,  amount for  1995
    consists of income tax gross-ups for (a) reverse split-dollar life insurance
    - $14,352, and (b) financial counseling benefit - $4,611.
 
                                      142
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
(3)  The restricted  stock award  to Mr.  Davis consists  of 1.67  shares of HDC
    common stock which had an estimated  net book value of $269,132 at  December
    31,  1995.  Dividends are  not paid  on Mr.  Davis' restricted  stock. These
    shares vest at a rate  of 0.4175 shares per  year beginning on December  21,
    1994, and will be fully vested on March 31, 1997, subject to earlier vesting
    in  certain  cases. These  shares are  subject  to transfer  restrictions in
    accordance with  a Restricted  Stock  Agreement between  WPLH, HDC  and  Mr.
    Davis.  WPLH  loaned to  Mr. Davis  $125,053 which  equals the  income taxes
    withheld in connection with shares vested as of December 31, 1995. Mr. Davis
    is charged interest on the loan at the prime rate.
 
(4) Stock  option  grants made  in  1995  were in  combination  with  contingent
    dividend  awards  as described  in the  table entitled  "Long-Term Incentive
    Awards in 1995."
 
(5) All  Other Compensation  for  1995 consists  of: matching  contributions  to
    401(k)  plan, Mr.  Davis --  $12,781, Mr. Harvey  -- $6,202,  Mr. Protsch --
    $6,000, Mr.  Ahearn --  $4,620 and  Mr. Amato  $4,704; financial  counseling
    benefit,  Mr. Davis  -- $5,000;  split dollar  life insurance  premiums, Mr.
    Davis -- $28,171, Mr. Harvey --  $11,102, Mr. Protsch -- $9,669, Mr.  Ahearn
    --  $18,002, and Mr.  Amato -- $6,908; reverse  split dollar life insurance,
    Mr. Davis  -- $15,561,  Mr. Harvey  -- $6,230,  Mr. Protsch  -- $4,509,  Mr.
    Ahearn  -- $7,041,  and Mr.  Amato -- $6,447.  The split  dollar and reverse
    split dollar insurance premiums are calculated using the "foregone interest"
    method.
 
STOCK OPTIONS
 
    WPLH has in  effect the  WPLH Long-Term  Equity Incentive  Plan pursuant  to
which,  among other awards, options to purchase WPLH Common Stock may be granted
to key employees (including  executive officers) of  WPLH and its  subsidiaries.
The  following  table sets  forth certain  information concerning  stock options
granted during 1995 to the executive officers named in the Summary  Compensation
Table.
 
                           OPTION/SAR GRANTS IN 1995
 
<TABLE>
<CAPTION>
                                                                                                         POTENTIAL REALIZABLE
                                                                INDIVIDUAL GRANTS
                                           ------------------------------------------------------------    VALUE AT ASSUMED
                                              NUMBER OF       % OF TOTAL                                   ANNUAL RATES OF
                                             SECURITIES      OPTIONS/ SARS                                STOCK APPRECIATION
                                             UNDERLYING       GRANTED TO      EXERCISE OR                FOR OPTION TERM (2)
                                            OPTIONS/SARS     EMPLOYEES IN     BASE PRICE    EXPIRATION   --------------------
NAME                                         GRANTED (1)      FISCAL YEAR      ($/SHARE)       DATE        5%($)     10%($)
- -----------------------------------------  ---------------  ---------------  -------------  -----------  ---------  ---------
<S>                                        <C>              <C>              <C>            <C>          <C>        <C>
Erroll B. Davis, Jr......................        13,100               31%          27.50        1/3/05     226,630    574,304
William D. Harvey........................         4,700               11%          27.50        1/3/05      81,310    206,048
Eliot G. Protsch.........................         4,700               11%          27.50        1/3/05      81,310    206,048
Lance W. Ahearn..........................            NA               NA              NA            NA          NA         NA
Anthony J. Amato.........................         3,650                9%          27.50        1/3/05      63,145    160,016
</TABLE>
 
- ------------------------
(1)  Consists of non-qualified  stock options to purchase  shares of WPLH Common
    Stock granted pursuant  to WPLH's Long-Term  Equity Incentive Plan.  Options
    were  granted on January  3, 1995, and  will fully vest  on January 3, 1998.
    These options  were granted  with  an equal  number of  contingent  dividend
    awards  as described  in the table  entitled "Long-Term  Incentive Awards in
    1995" and have per share exercise prices equal to the fair market value of a
    share of WPLH Common Stock on the date of grant. Upon a "change in  control"
    of  WPLH  as  defined  in  the  Long-Term  Equity  Incentive  Plan  or  upon
    retirement, disability or death  of the option  holder, these options  shall
    become  immediately exercisable.  Upon exercise  of an  option, the optionee
    purchases all or a portion of the shares covered by the option by paying the
    exercise price multiplied by the number of shares as to which the option  is
    exercised,  either in  cash or by  surrendering shares of  WPLH Common Stock
    already owned by the optionee.
 
(2) The hypothetical potential  appreciation shown for  the named executives  is
    required  by the SEC  rules. The amounts  shown do not  represent either the
    historical or expected future performance
 
                                      143
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
    of  WPLH Common  Stock. For  example, in order  for the  named executives to
    realize the potential  values set forth  in the  5% and 10%  columns in  the
    table  above, the price per share of WPLH's Common Stock would be $44.80 and
    $71.34, respectively, as of the expiration date of the options.
 
    The following table provides information for the executive officers named in
the Summary Compensation  Table regarding  the number and  value of  unexercised
options. No options were exercised by such officers during 1995.
 
                        OPTION/SAR EXERCISES IN 1995 AND
                     OPTION/SAR VALUES AT DECEMBER 31, 1995
 
<TABLE>
<CAPTION>
                                                                 NUMBER OF SECURITIES        VALUE OF UNEXERCISED IN-THE-
                                                                UNDERLYING UNEXERCISED        MONEY OPTIONS/SARS AT YEAR
                                                               OPTIONS/SARS AT YEAR END                END (1)
                                                            ------------------------------  ------------------------------
NAME                                                          EXERCISABLE    UNEXERCISABLE    EXERCISABLE    UNEXERCISABLE
- ----------------------------------------------------------  ---------------  -------------  ---------------  -------------
<S>                                                         <C>              <C>            <C>              <C>
Erroll B. Davis, Jr.......................................             0          13,100               0      $    40,938
William D. Harvey.........................................             0           4,700               0           14,688
Eliot G. Protsch..........................................             0           4,700               0           14,688
Lance W. Ahearn...........................................            NA              NA              NA               NA
Anthony J. Amato..........................................             0           3,650               0           11,406
</TABLE>
 
- ------------------------
 
(1)  Based on the  closing per share price  on December 29,  1995 of WPLH Common
    Stock of $30 5/8.
 
LONG-TERM INCENTIVE AWARDS
 
    The following  table  provides information  concerning  long-term  incentive
awards  made  in  1995  to  the  executive  officers  named  in  the  Summary of
Compensation Table.
 
                       LONG-TERM INCENTIVE AWARDS IN 1995
 
<TABLE>
<CAPTION>
                                            PERFORMANCE    ESTIMATED FUTURE PAYOUTS UNDER
                         NUMBER OF SHARES,    OR OTHER     NON-STOCK PRICE-BASED PLANS (2)
                          UNITS OR OTHER    PERIOD UNTIL  ---------------------------------
                              RIGHTS         MATURATION    THRESHOLD    TARGET     MAXIMUM
         NAME                 (#)(1)         OR PAYOUT        ($)         ($)        ($)
- -----------------------  -----------------  ------------  -----------  ---------  ---------
<S>                      <C>                <C>           <C>          <C>        <C>
Erroll B. Davis, Jr.            13,100           1/3/98       61,622      77,028    134,799
William D. Harvey                4,700           1/3/98       22,109      27,636     48,363
Eliot G. Protsch                 4,700           1/3/98       22,109      27,636     48,363
Lance W. Ahearn                     NA               NA           NA          NA         NA
Anthony J. Amato                 3,650           1/3/98       17,170      21,462     37,559
</TABLE>
 
- ------------------------
(1)  Consists  of  Performance  Units  awarded  under  WPLH's  Long-Term  Equity
    Incentive  Plan in combination with stock options (as described in the table
    entitled "Option/SAR Grants in 1995"). These Performance Units are  entirely
    in  the form of  contingent dividends and  will be paid  if total shareowner
    return over a three-year period ending January 3, 1998 equals or exceeds the
    median return earned  by the companies  in a peer  group of utility  holding
    companies,  except that there will  be no payment if  WPLH's total return is
    negative over the course of such period. If payable, each participant  shall
    receive  an amount equal to  the accumulated dividends paid  on one share of
    WPLH Common Stock during  the period of January  3, 1995 through January  2,
    1998   multiplied  by  the  number  of  performance  units  awarded  to  the
    participant, and modified by a performance multiplier which ranges from 0 to
    1.75 based on WPLH total return relative to the peer group.
 
(2) Assumes, for purposes of illustration only, a two cent per share increase in
    the annual dividend on shares of WPLH Common Stock for 1996 and 1997.
 
                                      144
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
CERTAIN TRANSACTIONS AND AGREEMENTS WITH EXECUTIVES
 
    WPLH has entered into  employment and severance  agreements with certain  of
its  executive  officers and  certain  executive officers  of  its subsidiaries,
including Messrs. Davis, Harvey, Protsch, Ahearn and Amato. For a description of
these agreements,  see "The  Mergers  -- Interests  of  Certain Persons  in  the
Mergers -- Severance Agreements."
 
    WPLH  and HDC also entered into a  Restricted Stock Agreement with Mr. Davis
in relation to the award to Mr. Davis in 1994 of 1.67 shares of HDC common stock
as shown  in the  Summary Compensation  Table. (See  footnote 3  to the  Summary
Compensation  Table for additional information on the  award of HDC stock to Mr.
Davis.) The agreement  restricts the transfer  of the HDC  stock awarded to  Mr.
Davis  and gives HDC the right of first  refusal on any proposed transfer of the
stock, at prices per share as  determined in accordance with the agreement.  The
agreement  also provides for  the sale of the  stock by Mr. Davis  to HDC in the
event of a  sale of  HDC, and,  beginning on March  31, 1997,  provides for  the
conversion  of the HDC stock into WPLH Common  Stock over a period of five years
at a ratio as determined in accordance with the agreement.
 
    WPLH and HDC also have in place a Restricted Stock Agreement with Mr. Ahearn
in connection with an award to Mr. Ahearn of five shares of HDC common stock  in
1991.  The final portion  of Mr. Ahearn's  restricted stock vested  in 1994. The
provisions of the agreement with Mr. Ahearn are similar to the provisions of the
agreement with Mr. Davis.  HDC has loaned  to Mr. Ahearn  an amount of  $485,401
which  equals the income taxes withheld in connection with HDC shares awarded to
him. Mr.  Ahearn is  charged interest  on  the loan  at the  prime rate.  It  is
currently  anticipated that HDC will repurchase  1.80 shares of HDC common stock
from Mr.  Ahearn  at the  most  recent per  share  value, as  determined  by  an
independent  appraiser selected by  the Compensation and  Personnel Committee of
the WPLH Board and Mr. Ahearn.
 
RETIREMENT AND EMPLOYEE BENEFIT PLANS
 
    Salaried employees (including  officers) of  WPLH and WP&L  are eligible  to
participate  in a Retirement Plan maintained by WP&L. Mr. Ahearn is not eligible
to participate in the  plan. All of  the other executive  officers named in  the
Summary  Compensation Table participated in  the plan during 1995. Contributions
to the  plan are  determined actuarially,  computed on  a straight-life  annuity
basis, and cannot be readily calculated as applied to any individual participant
or  small group  of participants. For  purposes of the  plan, compensation means
payment  for  services  rendered,  including  vacation  and  sick  pay,  and  is
substantially equivalent to the salary amounts reported in the foregoing Summary
Compensation  Table. Retirement Plan benefits depend upon length of plan service
(up to a maximum  of 30 years),  age at retirement,  and amount of  compensation
(determined  in accordance with the plan) and are reduced by up to 50 percent of
Social Security benefits. Credited years of  service under the plan for  covered
persons  named in the  foregoing Summary Compensation Table  are as follows: Mr.
Davis, 16 years; Mr. Protsch,  16 years; Mr. Amato, 9  years; and Mr. Harvey,  8
years.  Assuming  retirement  at  age  65,  a  Retirement  Plan  participant (in
conjunction with  the Unfunded  Supplemental  Retirement Plan  described  below)
would  be  eligible at  retirement for  a maximum  annual retirement  benefit as
follows:
 
                                      145
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
                             RETIREMENT PLAN TABLE
 
<TABLE>
<CAPTION>
   AVERAGE                  ANNUAL BENEFIT AFTER SPECIFIED YEARS IN PLAN*
   ANNUAL      ------------------------------------------------------------------------
COMPENSATION       5         10          15           20           25           30
- -------------  ---------  ---------  -----------  -----------  -----------  -----------
<S>            <C>        <C>        <C>          <C>          <C>          <C>
 $   125,000   $  10,210  $  20,421  $    30,631  $    40,841  $    51,052  $    61,262
     150,000      12,502     25,004       37,506       50,008       62,510       75,012
     200,000      17,085     34,171       51,256       68,341       85,427      102,512
     250,000      21,669     43,337       65,006       86,675      108,343      130,012
     300,000      26,252     52,504       78,756      105,008      131,260      157,512
     350,000      30,835     61,671       92,506      123,341      154,177      185,012
     400,000      35,419     70,837      106,256      141,675      177,093      212,512
     450,000      40,002     80,004      120,006      160,008      200,010      240,012
     475,000      42,294     84,587      126,881      169,175      211,468      253,762
     500,000      44,585     89,171      133,756      178,341      222,927      267,512
     525,000      46,877     93,754      140,631      187,508      234,385      281,262
</TABLE>
 
- ------------------------
* Average annual  compensation is  based  upon the  average  of the  highest  36
  consecutive  months of compensation. The  Retirement Plan benefits shown above
  are net  of  estimated  Social  Security  benefits  and  do  not  reflect  any
  deductions  for  other amounts.  The  annual retirement  benefits  payable are
  subject to  certain maximum  limitations (in  general, $120,000  for 1995  and
  $120,000  for 1996) under the Internal Revenue Code. Under the Retirement Plan
  and a supplemental  survivors income  plan, if a  Retirement Plan  participant
  dies  prior  to  retirement, the  designated  survivor of  the  participant is
  entitled to a monthly  income benefit equal to  approximately 50 percent  (100
  percent  in  the  case  of  certain  executive  officers  and  key  management
  employees) of the monthly retirement benefit which would have been payable  to
  the  participant under  the Retirement  Plan if  the participant  had remained
  employed by WPLH until eligible for normal retirement.
 
    UNFUNDED SUPPLEMENTAL  RETIREMENT  PLAN    --  WP&L  maintains  an  Unfunded
Supplemental  Retirement  Plan which  provides funds  for payment  of retirement
benefits above the limitations on payments from qualified pension plans in those
cases where an employee's retirement benefits exceed the qualified plan  limits.
Additionally, the plan provides for payments of supplemental retirement benefits
to  employees holding the  position of Vice  President or higher,  who have been
granted additional months of service by the WPLH Board for purposes of computing
retirement benefits. The benefits  payable under this plan  are included in  the
amounts disclosed in the Retirement Plan Table set forth above.
 
    UNFUNDED  EXECUTIVE TENURE COMPENSATION PLAN   -- WP&L maintains an Unfunded
Executive Tenure Compensation Plan  to provide incentive  for key executives  to
remain  in the  service of  WP&L by  providing additional  compensation which is
payable only  if the  executive remains  with WP&L  until retirement  (or  other
termination  if approved by  the WPLH Board).  Participants in the  plan must be
designated by  the Chief  Executive Officer  of WP&L  and approved  by the  WP&L
Board.  Mr. Davis was the only active participant in the plan as of December 31,
1995. The plan provides for monthly  payments to a participant after  retirement
(at  or after age 65, or  with approval of the WP&L  Board, prior to age 65) for
120 months.  The payments  will be  equal  to 25  percent of  the  participant's
highest  average salary  for any consecutive  36-month period.  If a participant
dies  prior  to  retirement  or  before   120  payments  have  been  made,   the
participant's  beneficiary will receive monthly payments  equal to 50 percent of
such amount for 120  months in the  case of death before  retirement, or if  the
participant  dies after retirement, 50 percent of such amount for the balance of
the 120 months. Annual benefits of $104,500  would be payable to Mr. Davis  upon
retirement, assuming he continues in WP&L's service until retirement at the same
salary as was in effect on December 31, 1995.
 
                                      146
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
REPORT OF THE COMPENSATION AND PERSONNEL COMMITTEE ON EXECUTIVE COMPENSATION
 
    TO  OUR SHAREOWNERS:   The Compensation  and Personnel  Committee (the "WPLH
Committee") of  the WPLH  Board is  comprised of  five independent,  nonemployee
directors  who have no "interlocking" relationships,  as defined by the SEC. The
WPLH Committee assesses the effectiveness  and competitiveness of, approves  the
design  of, and administers executive  compensation programs within a consistent
total compensation  framework for  WPLH.  The WPLH  Committee also  reviews  and
approves   all  salary  arrangements  and  other  remuneration  for  executives,
evaluates executive performance, and considers  related matters. To support  the
WPLH  Committee in carrying  out its mission,  Hewitt Associates, an independent
consultant, is engaged to provide assistance in the development of comprehensive
executive compensation policies.
 
    The WPLH Committee is committed to implementing a total compensation program
for executives which  furthers WPLH's  mission. The  WPLH Committee,  therefore,
adheres  to the following compensation policies which are intended to facilitate
the achievement of WPLH's business strategies.
 
    - Total compensation should enhance WPLH's  ability to attract, retain,  and
      encourage  the development of  exceptionally knowledgeable and experienced
      executives, upon  whom,  in  large  part,  the  successful  operation  and
      management of WPLH depends.
 
    - Base  salary  levels  should  be  targeted at  the  median  level  paid to
      executives of companies in their respective industry(ies).
 
    - Incentive compensation programs should strengthen the relationship between
      pay and performance by emphasizing variable, at-risk compensation that  is
      consistent  with  meeting predetermined  WPLH, subsidiary,  and individual
      performance goals.
 
    COMPONENTS OF COMPENSATION.  The  WPLH Committee relates total  compensation
levels  for WPLH's senior  executives to the compensation  paid to executives of
similar companies in their  respective industry(ies). As  WPLH is a  diversified
utility  holding  company  with  both  regulated  and  nonregulated  operations,
comparison groups  are  customized to  the  respective industries  in  which  an
executive is involved. Utility executives' pay is compared to that of executives
at  utilities with similar operations in  both the Midwest and national markets,
as well as  to utilities  with similar revenue  levels, market  capitalizations,
employment  levels, and total  shareowner returns. Compensation  paid to holding
company executives, including Mr. Davis, is compared to the compensation paid by
the same  utility  comparison group.  However,  in order  to  recognize  holding
company   employees  for  increasing   nonregulated  business  responsibilities,
benchmark data  also  are  drawn from  similarly  sized  diversified  industrial
companies   furnished  by   public  survey   data.  For   executives  with  sole
responsibilities in the nonregulated  businesses, comparison group data  reflect
the relevant mix of the nonregulated business operations.
 
    The  WPLH Committee  has reviewed  overall compensation  levels and compared
them to the benchmarks established. It has been determined that total  executive
compensation,  including that for Mr.  Davis, is in line  with the median of the
comparison groups of companies.
 
    The current  elements  of WPLH's  executive  compensation program  are  base
salary,  short-term (annual) incentives and long-term (equity) incentives. These
elements are  addressed  separately  below. In  determining  each  component  of
compensation,  the WPLH Committee considers all elements of an executive's total
compensation package, including benefit and perquisite programs.
 
    BASE SALARIES.  The  WPLH Committee annually  reviews each executive's  base
salary.  Base salaries are targeted at  the median of the executive's respective
industry market  rate  when  comparing both  utility  and  non-utility  (general
industry)  data. Base  salaries are adjusted  annually by the  WPLH Committee to
recognize changes  in  market  rate, varying  levels  of  responsibility,  prior
experience, breadth of knowledge as well as internal equity issues. Increases to
base salaries are driven primarily
 
                                      147
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
by market rate adjustments. Individual performance factors are not considered by
the WPLH Committee in setting base salaries. In 1995, executives did not receive
an  across-the-board salary adjustment. Certain  executives received base salary
increases in recognition of changes in  current market rates. Mr. Davis did  not
receive  a base salary increase in 1995  as his salary level corresponded to the
median of  the  targeted  market  range. Greater  emphasis  was  placed  on  the
opportunity  for executives to increase  their earnings through annual incentive
plans by exceeding specific  strategic goals. Base pay  adjustments are tied  to
median  market rate changes and will minimize across-the-board increases. During
1995, all executive salaries were reviewed for median market rate  comparability
utilizing  utility and general  industry data contained  in compensation surveys
published by Edison  Electric Institute,  American Gas  Association and  several
compensation  consulting firms.  Any recommended  changes will  be effective for
1996. Market rates will be reviewed annually.
 
    SHORT-TERM INCENTIVES.  The goal  of short-term (annual) incentive  programs
is  to promote the WPLH  Committee's pay-for-performance philosophy by providing
executives with direct financial incentives in the form of annual cash or  stock
based  bonuses  to  achieve corporate,  subsidiary,  and  individual performance
goals. Annual  bonus  opportunities  allow the  WPLH  Committee  to  communicate
specific  goals  that  are of  primary  importance  during the  coming  year and
motivate executives to  achieve these  goals. The  WPLH Committee  on an  annual
basis  reviews and  approves the  program's performance  goals and  the relative
weight assigned to each  goal as well  as targeted and  maximum award levels.  A
description of the short-term incentive programs available to executive officers
follows.
 
    WP&L  MANAGEMENT INCENTIVE PLAN  -- The WP&L  Management Incentive Plan (the
"WP&L MIP") covers utility executives and in 1995 was based on achieving  annual
targets   in  several  areas  of  overall  corporate  performance  that  include
profitability, operations  and maintenance  expense control,  reduction in  lost
time  accidents,  and  achievement of  electric  service  reliability standards.
Target and maximum bonus  awards were set  at the median  of the utility  market
levels.  Targets were  considered by  the WPLH  Committee to  be achievable, but
require above-average performance  from each  of the executives.  For 1995,  the
threshold  levels for all WP&L MIP  performance categories were exceeded. Actual
payment of bonuses, as a percentage of annual salary, is determined by the level
of performance achieved in each category.  Weighting factors are applied to  the
percentage  achievement under each category to determine overall performance. If
the threshold  performance level  is  not reached,  there  is no  bonus  payment
associated   with  that   particular  category.  Once   the  designated  maximum
performance is reached, there is no additional payment. The actual percentage of
salary paid as a  bonus, within the  allowable range, is  equal to the  weighted
average  percent achievement for all the performance categories. For example, if
the overall weighted performance achievement is 70%, the executive will  receive
70% of his or her maximum allowable bonus award. The WP&L MIP awarded 64 percent
of  its allowable  maximum for  1995. Potential  WP&L MIP  awards for executives
range from 0 to  40 percent of annual  salary. The WP&L MIP  does not allow  for
discretion  in bonus determinations. Awards for 1995  under the WP&L MIP made to
top executives (other than to Mr. Davis and Mr. Ahearn) are shown in the Summary
Compensation Table.
 
    HDC MANAGEMENT INCENTIVE PLAN -- Mr. Ahearn and selected other executives of
HDC are covered by the  HDC Management Incentive Plan  (the "HDC MIP") which  is
based  on  achievement of  specified combinations  of  net income  and after-tax
return on capital invested in  HDC and on achieving  a number of other  specific
HDC performance objectives which included the development of business strategies
for  certain  new ventures  and restructuring  and  growth targets  for existing
operating units. The incentive  compensation plan for Mr.  Ahearn consists of  a
potential  award maximum of 80 percent of his base salary; 75 percent associated
with performance in the net income and after-tax return category and 25  percent
for  the achievement of specific personal  performance goals. The actual payment
of bonuses as a percentage of annual  salary is determined as described for  the
WP&L  MIP. In 1995, the  threshold level of net  profit and after-tax return was
not achieved so  that there was  no payout  for this component.  Mr. Ahearn  did
exceed the minimum performance for his personal goals
 
                                      148
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
which resulted in a payout for this component. The HDC MIP awarded 22 percent of
its  allowable maximum in  1995 solely based  on performance in  relation to the
preestablished objectives. Mr. Ahearn's award for 1995 under the HDC MIP is  set
forth in the Summary Compensation Table.
 
    WPLH  MANAGEMENT INCENTIVE PLAN - Mr.  Davis is covered by WPLH's Management
Incentive Plan (the "WPLH MIP").  Awards under the WPLH  MIP are based on  WP&L,
HDC  and individual performance achievement  in relation to predetermined goals.
For  each  plan  year,  the  WPLH  Committee  will  determine  the   performance
apportionment  for  Mr.  Davis. In  1995  that  apportionment was  50%  for WP&L
performance, 25% for HDC  performance and 25%  for individual performance.  WP&L
performance  is measured based  on the overall  percentage achievement factor of
the corporate goals established  for the WP&L MIP.  HDC performance is  measured
based  on the overall percentage  achievement of the 1995  return on capital and
net income matrix from the HDC plan. Individual performance is measured based on
the achievement of certain specific  goals, which included strategy  development
and  implementation, established for  Mr. Davis by the  WPLH Committee. The 1995
WPLH MIP award  range for Mr.  Davis was from  0% to 70%  of annual salary.  The
actual  payment of  bonuses as  a percentage of  annual salary  is determined as
described for the  WP&L MIP. In  1995, the WPLH  MIP provided a  payment to  Mr.
Davis  as a result of  the achievement of goals under  the WP&L MIP as described
above and  for  achievement  of  the personal  goals  established  by  the  WPLH
Committee.  There was  no payout under  the HDC performance  component. For 1995
performance, Mr. Davis' annual bonus payment represented 29% of his base salary,
as reflected in the  Summary Compensation Table. Under  the WPLH MIP, Mr.  Davis
was  awarded $125,496  solely in connection  with 1995  performance as discussed
above. In the judgment of the WPLH Committee, Mr. Davis' award range is in  line
with  the median  of the same  combined utility and  general industry comparison
group used for base salary comparisons.
 
    LONG-TERM INCENTIVES.  The WPLH Committee strongly believes compensation for
senior executives  should  include  long-term, at-risk  pay  to  strengthen  the
alignment  of  shareowner and  management  interests at  both  the WP&L  and HDC
levels. In this regard, the Long-Term Equity Incentive Plan allows for grants of
stock options, restricted  stock, and performance  units/shares with respect  to
WPLH  Common Stock. The  WPLH Committee believes  the Long-Term Equity Incentive
Plan balances WPLH's existing compensation programs by emphasizing  compensation
based  on the long-term  successful performance of WPLH  from the perspective of
the shareowners. Stock  options provide a  reward that is  directly tied to  the
benefit  shareowners receive from  increases in the price  of WPLH Common Stock.
The payout from the  performance units is based  on WPLH's continued payment  of
dividends,  a significant component of investment returns for utilities, and the
relative total return to shareowners  compared to other comparable  investments.
Thus  the two  components of  the Long-Term  Equity Incentive  Plan, I.E., stock
options and  performance units,  provide incentives  for management  to  produce
superior  shareowner returns on both an absolute and relative basis. During 1995
the WPLH Committee made a grant of stock options and performance units to Messrs
Davis, Amato, Protsch and Harvey. All option grants were made at the fair market
value of WPLH  Common Stock on  the date  the grants were  approved (January  3,
1995). The options vest after three years and have a ten-year term from the date
of  the  grant.  Executives  were  also  granted  performance  units  which will
accumulate all of the dividends  paid on one share of  WPLH Common Stock over  a
three-year  period. One performance unit was granted for each option received by
the executive. Accrued dividends are not reinvested in WPLH Common Stock, nor is
any interest paid on  accrued dividends. Performance Units  will be paid out  in
cash  or in  shares of  WPLH Common  Stock. The  payment will  be modified  by a
performance multiplier  which ranges  from 0  to 1.75  based on  the three  year
average  of WPLH total  shareowner return relative to  a utility holding company
peer group.  If WPLH's  total shareowner  return for  the three  year period  is
negative,  the performance unit payout will be zero. In determining actual award
levels, the WPLH Committee was primarily concerned with providing a  competitive
total  compensation  level to  officers. As  such,  award levels  (including the
awards  made  to   Mr.  Davis)  were   based  on  a   competitive  analysis   of
similarly-sized  utility companies that took into consideration the market level
of  long-term  incentives,  as  well   as  the  competitiveness  of  the   total
compensation  package. Award  ranges, as well  as individual  award levels, were
then established based on responsibility level
 
                                      149
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
and market competitiveness. No corporate or individual performance measures were
reviewed in connection with the awards  of options and performance units.  Award
levels  were  targeted  to  the median  of  the  range of  such  awards  paid by
comparable companies.  In addition,  the  WPLH Committee  did not  consider  the
amounts  of  options  or  performance units  already  outstanding  or previously
granted since no options or performance units  have been granted by WPLH in  the
past.
 
    POLICY  WITH RESPECT TO THE  $1 MILLION DEDUCTION LIMIT.   Section 162(m) of
the Code  generally limits  the  corporate deduction  for compensation  paid  to
executive  officers  named in  the  proxy statement  to  $1 million  unless such
compensation is  based upon  performance objectives  meeting certain  regulatory
criteria  or is otherwise  excluded from the limitation.  The WPLH Committee has
carefully considered the impact  of this tax code  provision. Based on the  WPLH
Committee's  commitment to  link compensation  with performance  as described in
this report, the WPLH Committee  currently intends to qualify compensation  paid
to WPLH's executive officers for deductibility by WPLH under Section 162(m).
 
    CONCLUSION.  The WPLH Committee believes the existing executive compensation
policies  and programs provide the appropriate level of competitive compensation
for WPLH executives. In addition, the WPLH Committee believes that the long  and
short  term performance incentives effectively align the interests of executives
and shareowners toward a successful future for WPLH.
 
                                          COMPENSATION AND PERSONNEL
                                          COMMITTEE
                                          Arnold M. Nemirow (Chair)
                                          Milton E. Neshek
                                          Henry C. Prange
                                          Judith D. Pyle
                                          Carol T. Toussaint
 
                                      150
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
                COMPARISON OF FIVE-YEAR CUMULATIVE TOTAL RETURN
 
    Rules of the SEC require that WPLH show a graphical comparison of the  total
return  on the WPLH Common  Stock for the last five  fiscal years with the total
returns of a broad market  index and a more  narrowly focused industry or  group
index.  (Total  return  is  defined  as the  return  on  common  stock including
dividends and  stock price  appreciation, assuming  reinvestment of  dividends.)
WPLH  has selected the Standard  & Poors ("S&P") 500  index for the broad market
index, and  the S&P  Utility Index  as the  industry index.  These indices  were
selected  because  of their  broad availability  and recognition.  The following
chart compares the total return of an investment of $100 in WPLH Common Stock on
December 31, 1990, with like returns for the S&P 500 and S&P Utilities indices.
 
                      CUMULATIVE TOTAL SHAREHOLDER RETURN
           WPL HOLDINGS, INC.; S&P 500 INDEX; AND S&P UTILITIES INDEX
 
                                 [LOGO]
 
<TABLE>
<CAPTION>
                                               1990       1991       1992       1993       1994       1995
                                             ---------  ---------  ---------  ---------  ---------  ---------
<S>                                          <C>        <C>        <C>        <C>        <C>        <C>
WPL Holdings, Inc.                           $  100.00  $  143.10  $  156.54  $  160.41  $  142.51  $  170.34
S&P Utilities Index                          $  100.00  $  114.62  $  123.89  $  141.79  $  130.52  $  185.38
S&P 500 Index                                $  100.00  $  130.57  $  140.60  $  154.64  $  156.64  $  215.49
</TABLE>
 
      COMPLIANCE WITH SECTION 16(A) OF THE SECURITIES EXCHANGE ACT OF 1934
 
    WPLH's directors, its  executive officers,  and certain  other officers  are
required to report their ownership of WPLH Common Stock and WP&L Preferred Stock
and  any changes in that ownership to the SEC and the NYSE. All required filings
in 1995 were properly made in a timely fashion. In making the above  statements,
WPLH  has relied on the representations of the persons involved and on copies of
their reports filed with the SEC.
 
                                      151
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
                           ELECTION OF IES DIRECTORS
 
    Nine directors will be elected by the IES shareholders at the IES Meeting to
serve  until the next  annual meeting or until  their respective successors have
been duly elected and qualified. All  nine of the nominees have previously  been
elected as directors by the shareholders.
 
    In  the event that any nominee should become unavailable for election, which
is not  now contemplated,  the  IES Board  reserves discretionary  authority  to
designate  a substitute nominee. Proxies will be  voted for the election of such
other nominee or nominees as may be so designated by the IES Board.
 
                       NOMINEES FOR ELECTION AS DIRECTORS
 
<TABLE>
<CAPTION>
                                                                                                    YEAR FIRST
                       NAME AND AGE                                                             ELECTED A DIRECTOR
                       -----------------------------------------------------------------------  -------------------
<S>                    <C>                                                                      <C>
                       C.R.S. ANDERSON, 68                                                                1978
INSERT PICTURE #1      Mr. Anderson is  the retired Chairman  of the Board  of IES after  serving in that  position
                       following  the merger of IE Industries Inc. and  Iowa Southern Inc. Prior to the merger, Mr.
                       Anderson was  Chairman and  President  of Iowa  Southern Inc.,  and  had served  in  various
                       positions  at Iowa  Southern Utilities  Company since  1956. He  is a  past chairman  of the
                       Missouri Valley Electric Association and the Iowa Association of Business and Industry;  and
                       a  former director of IMG  Bond Accumulation Fund, IMG  Stock Accumulation Fund, Midwest Gas
                       Association and the Iowa  Business Development Credit Corporation.  Mr. Anderson has been  a
                       director  of IES  since 1991 and  was first elected  to the Iowa  Southern Utilities Company
                       board in  1978.  Mr.  Anderson serves  on  the  Executive Committee  and  chairs  the  Audit
                       Committee.
 
                       J. WAYNE BEVIS, 61                                                                 1987
INSERT PICTURE #2      Mr.  Bevis is Vice Chairman of Pella Corporation, a window and door manufacturing company in
                       Pella, Iowa. Mr.  Bevis retired on  December 31, 1995  as Chief Executive  Officer of  Pella
                       Corporation.  He has served in various positions  at Pella Corporation since 1973. Mr. Bevis
                       is Chairman of several Pella  Corporation subsidiaries and a  member of the Policy  Advisory
                       Board  of the Joint  Center of Housing Studies  of Harvard University  and the University of
                       Iowa College of Business  Board of Visitors. He  is a member and  past chairman of the  Iowa
                       Business  Council. Mr. Bevis has been a director of  IES since 1991 and was first elected to
                       the IE Industries Inc. board in 1987. Mr. Bevis serves on the Audit Committee.
 
                       LEE LIU, 62                                                                        1981
INSERT PICTURE #3      Mr. Liu is Chairman of the Board, President & Chief Executive Officer of IES and is Chairman
                       of the Board, President & Chief Executive Officer of Utilities. Mr. Liu has held a number of
                       professional, management and executive positions since joining Iowa Electric Light and Power
                       Company in 1957. He is a director of: HON Industries Inc., an office equipment  manufacturer
                       in Muscatine, Iowa; Principal Financial Group, an insurance company in Des Moines, Iowa; and
                       Eastman  Chemical Company, a  diversified chemical company in  Kingsport, Tennessee. He also
                       serves as a trustee  for Mercy Medical  Center, a hospital  in Cedar Rapids,  Iowa and is  a
                       member of the Iowa Business Council, the Iowa Utility Association and the University of Iowa
                       College of Business Board of Visitors. Mr. Liu has been a director of IES since 1991 and was
                       first  elected to the board of Iowa Electric Light and Power Company in 1981. Mr. Liu chairs
                       the Executive Committee and serves on the Nominating Committee.
</TABLE>
 
                                      136
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
<TABLE>
<CAPTION>
                                                                                                    YEAR FIRST
                       NAME AND AGE                                                             ELECTED A DIRECTOR
                       -----------------------------------------------------------------------  -------------------
                       JACK R. NEWMAN, 62                                                                 1994
<S>                    <C>                                                                      <C>
INSERT PICTURE #4      Mr. Newman has been a Partner of Morgan, Lewis & Bockius, an international law firm based in
                       Washington, D.C., specializing in energy matters since December 1, 1994. Mr. Newman has been
                       engaged in private practice since 1967 and was previously a partner in the law firms  Newman
                       &  Holtzinger and Newman, Bouknight &  Edgar. He has served as  nuclear legal counsel to IES
                       since 1968. Prior to 1967, Mr. Newman served as Secretary and General Counsel of the Nuclear
                       Materials and  Equipment  Corporation  and  as Staff  Counsel  to  the  Joint  Congressional
                       Committee  on  Atomic Energy.  He advises  a number  of utility  companies on  nuclear power
                       matters, including many European and Asian companies. Mr.  Newman is a member of the Bar  of
                       the  State of New York, the Bar Association  of the District of Columbia, the Association of
                       the Bar of the City of  New York, the Federal Bar  Association and the Lawyers Committee  of
                       the  Edison Electric Institute. He was  first appointed to the board  of IES in August 1994.
                       Mr. Newman serves on the Compensation Committee.
 
                       ROBERT D. RAY, 67                                                                  1987
INSERT PICTURE #5      Mr. Ray is President and Chief Executive Officer of IASD Health Services Inc. (formerly Blue
                       Cross and Blue Shield of Iowa, Western Iowa and South Dakota) ("IASD"), an insurance firm in
                       Des Moines, Iowa. From 1983 until 1989 he was President and Chief Executive Officer of  Life
                       Investors,  Inc., an insurance firm in Cedar Rapids, Iowa. Mr. Ray served as Governor of the
                       State of Iowa for fourteen years, and was  the United States Delegate to the United  Nations
                       in  1984. He is a director of the  Maytag Company, an appliance manufacturer in Newton, Iowa
                       and a director of Norwest Bank  of Iowa in Des Moines, Iowa.  He also serves as Chairman  of
                       the National Leadership Commission on Health Care Reform and the National Advisory Committee
                       on  Rural Health Care. Mr. Ray  is a member of the  Board of Governors Drake University, Des
                       Moines, Iowa, and the Iowa Business  Council. He has been a  director of IES since 1991  and
                       was  first elected to the IE Industries Inc. board  in 1987. Mr. Ray serves on the Audit and
                       Nominating Committees.
 
                       DAVID Q. REED, 64                                                                  1967
INSERT PICTURE #6      Mr. Reed is an independent practitioner of law  in Kansas City, Missouri. Mr. Reed has  been
                       engaged  in the private practice  of law since 1960.  From 1972 until 1988,  he was a senior
                       member of the firm of Kodas, Reed & McFadden,  P.C. in Kansas City, Missouri. Mr. Reed is  a
                       member  of the American  Bar Association, the  Association of Trial  Lawyers of America, the
                       Missouri Association of Trial Attorneys, the  Missouri Bar and the Kansas City  Metropolitan
                       Bar  Association. He served in the Missouri General  Assembly from 1972 until 1974. Mr. Reed
                       has been a director of IES since 1991 and  was first elected to the Iowa Electric Light  and
                       Power  Company board  in 1967.  Mr. Reed serves  on the  Executive Committee  and chairs the
                       Nominating Committee.
</TABLE>
 
                                      137
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
<TABLE>
<CAPTION>
                                                                                                    YEAR FIRST
                       NAME AND AGE                                                             ELECTED A DIRECTOR
                       -----------------------------------------------------------------------  -------------------
                       HENRY ROYER, 64                                                                    1984
<S>                    <C>                                                                      <C>
INSERT PICTURE #7      Mr. Royer has been President and Chief  Executive Officer of River City Bank in  Sacramento,
                       California  since August 1994. He  served as Chairman of the  Board and President of Firstar
                       Bank of Cedar Rapids, N.A. from  1983 until 1994. Mr. Royer is  a director of CRST, Inc.,  a
                       trucking  company in Cedar  Rapids, Iowa and  has served on  numerous Cedar Rapids community
                       organization boards. He has been a director of  IES since 1991 and was first elected to  the
                       board  of Iowa Electric Light and  Power Company in 1984. Mr.  Royer serves on the Executive
                       Committee and chairs the Compensation Committee.
 
                       ROBERT W. SCHLUTZ, 60                                                              1989
INSERT PICTURE #8      Mr. Schlutz  is  President of  Schlutz  Enterprises,  a diversified  farming  and  retailing
                       business  in Columbus Junction,  Iowa. He is  a director of  Agri-Nutritional Group Inc., an
                       animal health business,  in St.  Louis, Missouri and  the Iowa  Foundation for  Agricultural
                       Advancement. Mr. Schlutz is a President of the Iowa State Fair Board and a member of various
                       community  organizations. He also served  on the National Advisory  Council for the Kentucky
                       Fried Chicken Corporation. He is a past chairman of the Environmental Protection  Commission
                       for  the State  of Iowa. Mr.  Schlutz has been  a director of  IES since 1991  and was first
                       elected to the Iowa Southern Inc. board in 1989. Mr. Schlutz serves on the Audit Committee.
 
                       ANTHONY R. WEILER, 59                                                              1979
INSERT PICTURE #9      Mr. Weiler is Senior  Vice President, Merchandising, for  Heilig-Meyers Company, a  national
                       furniture retailer with more than 750 stores headquartered in Richmond, Virginia. Mr. Weiler
                       was  previously Chairman  and Chief  Executive Officer  of Chittenden  & Eastman  Company, a
                       national manufacturer of mattresses  in Burlington, Iowa. He  was with Chittenden &  Eastman
                       from  1960 until 1995, and held various management  positions. Mr. Weiler is Chairman of the
                       National Home  Furnishings  Association  and  a director  of  the  Retail  Home  Furnishings
                       Foundation.  He is a  trustee of NHFA Insurance  and a past director  of the Burlington Area
                       Development Corporation,  the Burlington  Area  Chamber of  Commerce and  various  community
                       organizations. Mr. Weiler has been a director of IES since 1991 and was first elected to the
                       Iowa  Southern  Utilities  Company  board  in 1979.  Mr.  Weiler  serves  on  the Nominating
                       Committee.
</TABLE>
 
                                      138
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
Except as otherwise noted, all nominees  have served in their current  positions
for five years or more as of the date of this proxy. All other information is as
of January 1, 1996. All nominees are also the current directors of Utilities.
 
      THE IES BOARD RECOMMENDS A VOTE "FOR" THE ELECTION OF ALL NOMINEES.
                            ------------------------
                    SECURITY OWNERSHIP OF BENEFICIAL OWNERS
 
Set  forth below is certain information  with respect to beneficial ownership of
the IES Common  Stock by  each person  known by IES  to own  5% or  more of  the
outstanding IES Common Stock as of June 1, 1996:
 
<TABLE>
<CAPTION>
                                                                      AMOUNT AND NATURE
                                                                        OF BENEFICIAL           PERCENT
NAME OF BENEFICIAL OWNER                                                OWNERSHIP (1)        OF CLASS (1)
- ----------------------------------------------------------------  -------------------------  -------------
<S>                                                               <C>                        <C>
WPLH............................................................            5,861,115              16.4%
IPC.............................................................            5,861,115              16.4%
</TABLE>
 
- ------------------------
(1) By reason of the Stock Option Agreements, each of WPLH and IPC may be deemed
    to  have sole voting and dispositive power with respect to the shares listed
    above  which  are  subject  to  their  respective  Options  from  IES   and,
    accordingly,  each of WPLH and IPC may  be deemed to beneficially own all of
    such shares (assuming exercise  of its Option and  the nontriggering of  the
    other  party's right to exercise its  Option for IES Common Stock). However,
    each of WPLH  and IPC expressly  disclaim any beneficial  ownership of  such
    shares  because the Options  are exercisable only  in certain circumstances.
    See "The Stock Option Agreements."
 
                        SECURITY OWNERSHIP OF MANAGEMENT
 
    Set forth below is certain information with respect to beneficial  ownership
of  the IES Common  Stock as of  June 1, 1996  by each director  and nominee for
director, certain Executive Officers and by all directors and Executive Officers
of IES as a group:
 
<TABLE>
<CAPTION>
                                                                                   AMOUNT AND NATURE
                                                                                     OF BENEFICIAL           PERCENT
NAME OF BENEFICIAL OWNER                                                             OWNERSHIP (1)          OF CLASS
- -----------------------------------------------------------------------------  -------------------------  -------------
<S>                                                                            <C>                        <C>
C.R.S. Anderson..............................................................              19,000                .06%
J. Wayne Bevis...............................................................                 500              (2)
Blake O. Fisher, Jr..........................................................              16,415                .05%
John F. Franz, Jr............................................................              14,492                .05%
James E. Hoffman.............................................................               5,000                .02%
Lee Liu......................................................................              44,638                .15%
Rene H. Males................................................................               6,712                .02%
Jack R. Newman...............................................................                   0              (2)
Robert D. Ray................................................................                1,500             (2)
David Q. Reed................................................................                4,002                .01%
Larry D. Root................................................................               17,470                .06%
Henry Royer..................................................................                1,925             (2)
Robert W. Schlutz............................................................                1,399             (2)
Anthony R. Weiler............................................................                2,335             (2)
All Executive Officers and Directors of IES and Utilities as a group (20
 persons)....................................................................              168,556                .56%
</TABLE>
 
- ------------------------
(1) Includes ownership  of  shares  by family  members  even  though  beneficial
    ownership of such shares may be disclaimed.
 
(2) Less than .01% of the Class (IES Common Stock).
 
                                      139
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
                               OTHER TRANSACTIONS
 
    IES  has  a contract  with IASD  for administration  of its  employee health
insurance plan, as it has  for many prior years. In  1995, IES paid $291,285  to
IASD. Beginning in 1995, IES also contracted with IASD for administration of its
dental insurance plan and paid $63,925 to IASD for those services. As previously
stated, Mr. Ray is President and Chief Executive Officer of IASD.
 
                  FUNCTIONING OF THE IES BOARD AND COMMITTEES
 
    IES's  Board has  an Executive Committee,  an Audit  Committee, a Nominating
Committee and a Compensation Committee.
 
    Current members of  the Executive  Committee are Lee  Liu, Chairman,  C.R.S.
Anderson,  David Q.  Reed and  Henry Royer. The  current members  served on this
Committee during  1995.  The  Committee  met three  times  during  1995.  It  is
empowered  with all of the authority vested in the IES Board, subject to certain
limitations, and may act when the IES Board is not in session.
 
    Current members of  the Audit  Committee are C.R.S.  Anderson, Chairman,  J.
Wayne  Bevis, Robert D. Ray and Robert W. Schlutz. The current members served on
this Committee during 1995. The Committee  met twice during 1995. The  principal
functions  of  the  Committee are  to  review IES's  internal  audit activities,
including reviews of the internal  control procedures; to oversee the  corporate
compliance  process;  to  recommend  to  the  IES  Board  an  independent public
accounting firm to be IES's auditors; and to approve the audit arrangements  and
audit  results.  Both  the internal  and  independent auditors  have  direct and
independent access to the Audit Committee.
 
    Current members of the Nominating Committee are David Q. Reed, Chairman, Lee
Liu, Robert D. Ray  and Anthony R.  Weiler. The current  members served on  this
Committee  during  1995.  The Committee  met  twice during  1995.  Its principal
function is to review and  recommend to the IES Board  nominees to serve on  the
IES  Board  and  its  committees.  While there  are  no  formal  procedures, the
Committee considers nominees brought  to its attention by  other members of  the
IES Board, members of management and shareholders.
 
    The  Compensation Committee members  for 1995 and for  1996 (until April 12,
1996) were Henry Royer, Chairman; Dr. George Daly; G. Sharp Lannom, IV; and Jack
R. Newman. The Committee met  five times during 1995. Dr.  Daly was a member  of
the  Compensation Committee until his resignation from the Board of Directors on
April 3, 1996. Mr. Lannom was a  member of the Compensation Committee until  his
resignation  from the Board of Directors on  April 12, 1996. The current members
of the Compensation Committee are Henry Royer, Chairman; J. Wayne Bevis; Jack R.
Newman; and Anthony R. Weiler. The  principal functions of the Committee are  to
review  and make  recommendations to  the IES  Board on  the salaries  and other
compensation and benefits of the elected  officers of IES and its  subsidiaries,
and  to  review  and  administer incentive  compensation  or  similar  plans for
officers and other key employees of IES and its subsidiaries. The report of  the
Compensation    Committee   is    included   later    in   this    Joint   Proxy
Statement/Prospectus.
 
    IES's Board met ten times in 1995.  The various committees of the Board  met
an aggregate of twelve times. All of the directors attended 75% or more of these
meetings.
 
                           COMPENSATION OF DIRECTORS
 
    In  1995, non-employee  directors of IES  received an annual  fee of $12,000
plus $700  per Board  meeting  or Committee  meeting  attended. If  a  Committee
meeting  was the  same day  as a meeting  of the  IES Board as  a whole  or if a
Committee meeting was by  telephone conference, each participating  non-employee
director received $350, one-half the regular Committee meeting fee. In addition,
non-employee directors serving as chairman of a Committee received an annual fee
of  $1,500 for  serving in such  capacity. In  1993, the IES  Board decided that
directors who are  officers would  not receive  an annual  fee or  any fees  for
attendance  at  Board  meetings or  meetings  of  committees of  which  they are
 
                                      140
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
members. Robert F. Brewer  and Dr. Salomon Levy,  who served as directors  until
May 17, 1994, served as emeritus directors of IES until May 16, 1995. Mr. Brewer
received $1,400 in meeting fees in 1995 as an emeritus director.
 
    Under  the  Director Retirement  Plan, IES  provides  a retirement  or death
benefit to directors, including directors who are employees of IES, in an amount
equal to 80% of the annual directors fee. Such amount is payable annually, based
upon length of service, to directors who have served at least four years, with a
maximum payment period  of eight years.  Mr. Brewer and  Dr. Levy each  received
payments of $8,000 under the Director Retirement Plan in 1995.
 
    S.  Levy,  Incorporated, an  engineering and  management consulting  firm of
which Dr. Salomon  Levy, a director  emeritus until May  16, 1995, is  Chairman,
performed  consulting  services for  Utilities  in 1995  for  which it  was paid
$125,554.  Dr.  Levy  has  retired  as  Chief  Executive  Officer  of  S.  Levy,
Incorporated  and  does not  participate in  the  day to  day management  of the
company. Utilities has a service contract with S. Levy, Incorporated pursuant to
which it supplied  these services and  under which it  will provide services  in
1996.  Dr. Salomon  Levy was appointed  as the  Nuclear Advisor to  the Board of
Directors on  May 17,  1994 and  received $5,771  for his  services in  1995  as
Nuclear  Advisor.  Dr. Levy  also  serves on  the  IES Utilities  Nuclear Safety
Committee.
 
    Director Jack R.  Newman has served  as nuclear legal  counsel to IES  since
1968.  Mr. Newman's firm, Morgan,  Lewis & Bockius, was  paid $453,002 for legal
services provided to IES in 1995.
 
    IES makes available to members of  the Board of Directors a business  travel
accident  insurance policy  at an  annual cost  to IES  of $10  per director. No
director received any payments under such policy in 1995.
 
         REPORT OF THE COMPENSATION COMMITTEE ON EXECUTIVE COMPENSATION
 
    Under the supervision of  the Compensation Committee of  the IES Board,  IES
has  implemented compensation practices  intended to enhance  the performance of
IES and increase its value to all shareholders. In order to provide  information
on current and future practices of IES, the Compensation Committee has furnished
the following report on executive compensation.
 
COMPENSATION PHILOSOPHY
 
    The   Compensation  Committee  has  devoted  substantial  attention  to  the
philosophy of IES compensation. This  philosophy is intended to provide  guiding
principles for the future and is embodied in four primary objectives:
 
        1.  To provide incentives based on value delivered to IES's shareholders
    and customers.
 
        2.  To clearly link individual executive pay actions to performance.
 
        3.  To  maintain a  system of  rewards that  is structured competitively
            with industry standards.
 
        4.  To attract, motivate and retain executives of the highest quality.
 
    The most important performance yardstick in our compensation program is  our
ability  to deliver value  to shareholders through  appreciation in share price,
payment of  dividends and  their future  continuity. On  an ongoing  basis,  the
Committee  will  test  and refine  the  compensation  program to  ensure  a high
correlation between the level  of compensation and  the return to  shareholders.
Achieving desirable shareholder returns over a sustained period of time requires
management's  attention  to a  number of  financial and  non-financial strategic
elements which enable us to focus  on the current and long-term requirements  of
the customer. OUR COMPENSATION PROGRAM, THEREFORE, FOCUSES EXECUTIVES ON ACTIONS
THAT  DIRECTLY  IMPACT SHAREHOLDER  RETURN IN  THE SHORT-  AND LONG-TERM  AND BY
PROVIDING SERVICE TO OUR CUSTOMERS.
 
                                      141
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
    The Committee uses multiple sources of information to evaluate and establish
appropriate compensation practices.  While using  multiple sources,  we rely  on
data  from  a  utility  industry  peer group  of  companies  (as  listed  in the
Performance Graph below) to assess  IES's relative performance and  compensation
levels.  Peer  companies were  selected by  meeting multiple  criteria including
revenue size,  sources  of revenue,  geographic  location, markets  served,  and
comparable  operations.  Consistent  with  our  objectives,  the  Committee will
position its executives' total compensation target levels at the median of  this
peer  group  of companies.  The total  compensation target  levels for  the last
fiscal year for the  Chief Executive Officer and  Executive Officers in  general
were  consistent with said policy. Annual executive total compensation will fall
below, at, or above the median depending on individual and company performance.
 
    IES's executive compensation  program has three  components -- base  salary,
annual incentives and long-term incentives. The target mix of total compensation
for  executives will be an  approximate range of 50% to  75% base salary and the
remainder of  25%  to  50%  in  the  combined  total  of  short-  and  long-term
incentives.  The calculations for the short-  and long-term incentive awards for
the Chief Executive Officer and the Executive Officers in general are  described
later  in this report. Furthermore, the  Committee believes this mix, while more
variable than industry-wide practices, serves to  send a clear message to  IES's
executives that performance directly governs pay.
 
    The  Committee strongly believes that  incentive compensation should only be
awarded with commensurate performance. We have approved compensation plans which
include high threshold (minimum) levels of performance to ensure that incentives
are paid only when truly earned.
 
DESCRIPTION OF COMPENSATION PROGRAMS
 
    The  following  text  briefly  describes   the  role  of  each  element   of
compensation.
 
    BASE SALARY.  Base salary will be at levels sufficient to attract and retain
qualified  executives. Aggregate base salary  increases are intended to parallel
increases in  the pay  levels of  the utility  industry as  a whole.  Individual
executive  salary increases will reflect  the individual's level of performance,
current position within salary range, and utility industry trends.
 
    ANNUAL INCENTIVE.  IES's executive annual incentive plan serves to recognize
and reward executives for taking actions  that build the value of IES,  generate
competitive total returns to shareholders, and minimize cost to IES's customers.
The  formula for  annual incentive  awards recognizes  operational and financial
goals of significance to IES and is  based on IES's achievement of Earnings  Per
Share  ("EPS") versus a predetermined target and  a Cost to the Customer per Kwh
("CCK") measure versus a peer group  cost target, along with the achievement  of
individual  objectives. The criteria  for the annual  incentive plan is reviewed
prior to  the  beginning of  a  new fiscal  year.  Payments are  made  based  on
corporate  and  individual  performance  versus  target,  with  an  emphasis  on
CORPORATE over INDIVIDUAL.
 
    For the 1995 fiscal year, this plan had various incentive levels with target
award opportunities ranging from 12% to 35% of base salary. Awards based on  the
target  criteria of EPS and  CCK measure could range between  0% and 150% of the
target incentive level, with adjustments for individual performance. The EPS for
1995 was $2.20 and the CCK was 125.82. This corporate performance for 1995 based
on the predetermined financial and operational goals provided, in general,  120%
of  the target incentive  level with adjustments  for individual considerations.
There were no  adjustments for individual  performance made to  the 1995  fiscal
year  awards. Thus, the calculation for an  individual who had an opportunity to
earn 12% of base salary would be base  salary X 12% X 120%. The results of  this
plan  for  the Chief  Executive Officer  and the  Executive Officers  in general
appear in this Joint Proxy Statement/Prospectus.
 
    LONG-TERM INCENTIVES.   IES's  current long-term  incentive plan  serves  to
reward  executive performance  in successfully executing  the long-term business
strategy and building  shareholder value. The  plan allows for  the awarding  of
nonqualified  stock options,  stock appreciation  rights, restricted  stock, and
performance units payable in cash or stock.
 
                                      142
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
    The performance criteria for the  long-term incentive plan for fiscal  years
1993,  1994 and 1995 include total return  to shareholders versus the peer group
(35%), earnings growth versus three-year growth rates (35%) and  team/individual
performance  (30%). Each performance criteria could range between 0% and 125% of
the target incentive levels. For the 1994  and 1995 fiscal years, this plan  had
various incentive levels with target award opportunities ranging from 26% to 65%
of base salary.
 
    Awards  for 1994 performance were determined in  May 1995 and only shares of
restricted stock were granted. The corporate performance for 1994 for the  total
return  to shareholders versus the  peer group resulted in  an adjustment of 75%
and earnings growth versus three-year growth rates resulted in an adjustment  of
125%.  The third component, team/individual  performance, resulted in John Franz
receiving a 100% performance  rating and all other  executives receiving an  83%
performance  rating. The adjustment  percentage for all  executives, except John
Franz, would be (75%  X 35%) + (125%  X 35%) + (83%  X30%) or a 95%  adjustment.
Thus,  the calculation for  an executive who  had an opportunity  to earn 26% of
base salary would  be base salary  X 26% X  95%. This amount  is divided by  the
closing  price for IES Common Stock on the last trading day of the year for that
performance year to determine the number of  shares for the award. For the  year
1994, the closing price was $25.25. The value of the award is then determined by
the  number of shares of  common stock from the  previous calculations times the
closing price on the award  date. The closing price on  June 1, 1995, the  award
date  in 1995, was $22.625. The 1994  awards for the Chief Executive Officer and
the next highest paid Executive Officers  are shown in the Summary  Compensation
Table as 1994 compensation.
 
    Awards  for 1995 performance were determined in  May 1996 and only shares of
restricted stock were granted. The corporate performance for 1995 for the  total
return to shareholders versus the peer group resulted in an adjustment of 0% and
earnings  growth versus  three-year growth  rates resulted  in an  adjustment of
125%.  The  third  component,  team/individual  performance,  resulted  in   all
executives  receiving  a  100%  performance  rating.  Based  on  his  individual
performance, John  Franz was  granted  an extra  $10,000  of common  stock.  The
adjustment  percentage for all executives  would be (0% x 35%)  + (125% x 35%) +
(100% x 30%) or a 74% adjustment. Thus, the calculation for an executive who had
an opportunity to earn 26% of base salary would be base salary x 26% x 74%. This
amount is divided by the closing price for IES Common Stock on the last  trading
day  of the year for that performance year to determine the number of shares for
the award. For the  year 1995, the  closing price was $26.50.  The value of  the
award  is  then determined  by the  number of  shares of  common stock  from the
previous calculations times  the closing price  on the award  date. The  closing
price  on May 31, 1996, the award date in 1996, was $28.625. The 1995 awards for
the Chief Executive  Officer and the  next highest paid  Executive Officers  are
shown in the Summary Compensation Table as 1995 compensation.
 
    COMPENSATION  ADMINISTRATION.   The  Committee  follows an  annual  cycle to
administer each of the three components of executive compensation. The integrity
of our compensation program relies on a rigorous, annual performance  evaluation
process.  Moreover,  the  Committee's  evaluation process  includes  the  use of
outside consultants in order to assure it has the best possible information  and
an objective approach to the administration of compensation programs.
 
    DISCUSSION OF CHIEF EXECUTIVE OFFICER PAY.  Consistent with the compensation
philosophy,   the  Committee   managed  the  Chief   Executive  Officer's  total
compensation during 1995 based on the overall performance of IES and on relative
levels of compensation for Chief Executive Officers in the utility industry.
 
    The Committee took  the following  1995 compensation actions  for the  Chief
Executive Officer:
 
        1.    BASE  SALARY  AT  $340,000.   Generally,  base  salary  levels for
    management positions remained the same in 1995 as in 1994. Thus, Mr. Liu did
    not receive an increase in base salary, which remained at $340,000.
 
        2.   PROVIDED  A  CASH INCENTIVE  IN  1996  OF $142,800  BASED  ON  1995
    PERFORMANCE.  Mr. Liu's annual incentive target is 35% of base salary, which
    represents  a more variable approach than industry practices and is based on
    the  formula   for   annual  incentive   awards   as  set   forth   in   the
 
                                      143
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
    above  "Annual  Incentive"  section.  The formula  for  performance  in 1995
    provided 120%  of the  target incentive  with no  individual  consideration.
    Thus,  Mr. Liu's award was calculated by multiplying his base salary X 35% X
    120%.
 
        3.  GRANTED 8,315 SHARES OF RESTRICTED STOCK ON JUNE 1, 1995 AT A MARKET
    PRICE PER  SHARE  OF $22.625.    This grant  represents  a target  award  of
    restricted  stock under  the long-term  incentive plan  as set  forth in the
    above "Long-Term Incentive" section. Mr. Liu  received a grant of 61.75%  of
    base  salary based on  multiplying his base  salary X 65%  X 95%. This grant
    vests at a rate of 33% per year.
 
        4.  GRANTED 4,000 SHARES  OF RESTRICTED STOCK ON  DECEMBER 8, 1995 AT  A
    MARKET  PRICE PER SHARE OF  $27.50.  To recognize  Mr. Liu's contribution to
    IES, the Compensation Committee authorized  in 1990 a supplemental grant  of
    restricted  stock under  IES's Long-Term Incentive  Plan to be  given over a
    five-year period. The supplemental grant  of 4,000 restricted shares,  which
    will  remain restricted until Mr. Liu retires, was made pursuant to the 1990
    decision. The  number of  shares  granted in  1995  was based  on  financial
    achievements and specific objectives.
 
        5.  GRANTED 6,171 SHARES OF RESTRICTED STOCK ON MAY 31, 1996 AT A MARKET
    PRICE  PER  SHARE OF  $28.625.   This  grant  represents a  target  award of
    restricted stock under  the long-term  incentive plan  as set  forth in  the
    above  "Long Term Incentive" section.  Mr. Liu received a  grant of 48.1% of
    base salary based on  multiplying his base  salary x 65%  x 74%. This  grant
    vests at a rate of 33% per year.
 
    The  Committee is aware of the limitations recent tax legislation has placed
on the tax deductibility of compensation in excess of $1 million which is earned
in any year by  an Executive Officer. Currently  none of the Executive  Officers
has earned compensation subject to such limitations. The Committee will continue
to monitor developments in this area.
 
<TABLE>
<CAPTION>
                               Compensation Committee
 
<S>                            <C>                            <C>
                               Henry Royer, Chair             Dr. George Daly*
                               G. Sharp Lannom, IV**          Jack R. Newman
</TABLE>
 
 *Dr. Daly was a member of the Compensation Committee until his resignation from
  the Board of Directors on April 3, 1996.
 
**Mr.  Lannom was a  member of the Compensation  Committee until his resignation
  from the Board of Directors on April 12, 1996.
 
                                      144
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
                             EXECUTIVE COMPENSATION
 
    The following  table  shows,  for  the  fiscal  years  ending  December  31,
1993-1995,  the cash compensation  paid by IES  and its subsidiaries  as well as
certain other  compensation  paid or  accrued  for  those years,  to  the  Chief
Executive  Officer and  to each  of the  four most  highly compensated Executive
Officers of IES and its  subsidiaries and to Rene H.  Males who would have  been
among  the four most highly compensated executive officers if he was employed by
IES on December 31, 1995:
 
                           SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
                                                                                               LONG-TERM
                                                                                             COMPENSATION
                                                        ANNUAL COMPENSATION                 ---------------
                                         -------------------------------------------------    RESTRICTED        ALL OTHER
NAME AND PRINCIPAL POSITION (1)            YEAR         SALARY       BONUS (3)   OTHER (4)  STOCK AWARDS(5)  COMPENSATION (6)
- ---------------------------------------  ---------  --------------  -----------  ---------  ---------------  ----------------
<S>                                      <C>        <C>             <C>          <C>        <C>              <C>
Lee Liu                                       1995  $   340,000     $   142,800  $   1,588    $   176,645      $     13,507
 Chairman of the Board,                       1994      324,375         161,798      1,114        298,127            13,604
 President & Chief Executive Officer          1993      307,450(2)      157,500      1,625        237,341            10,571
Blake O. Fisher, Jr.                          1995      241,861          76,440        160        --                  6,945
 Executive Vice President &                   1994      210,060          88,800        160         88,894             7,138
 Chief Financial Officer                      1993      212,475(2)       81,974        720         74,049             4,392
James E. Hoffman                              1995       89,583         206,500     51,523        143,125               324
 Executive Vice President
Larry D. Root                                 1995      220,822(2)       62,606        566        --                208,038
 Executive Vice President                     1994      197,765          70,935        483         83,690             7,820
                                              1993      200,694(2)       77,176      2,168         69,724             5,948
John F. Franz, Jr.                            1995      144,050          25,213        418         41,993             4,893
 Vice President                               1994      127,379          30,062         57        257,473             1,863
                                              1993      114,425          32,577        171         28,634             1,035
Rene H. Males                                 1995      141,624(2)       38,084        780        --                358,244
 Executive Vice President                     1994      162,750          57,534      1,761        --                  4,910
                                              1993      179,024(2)       65,100        404        --                 25,817
</TABLE>
 
- ------------------------
(1) Messrs. Hoffman, Males and Franz are  not officers of IES, but are  officers
    of  Utilities.  Mr. Hoffman  commenced  employment with  Utilities effective
    August 1,  1995.  Mr. Fisher  resigned  his employment  with  IES  effective
    February  21, 1996. Mr. Root retired  effective December 31, 1995. Mr. Males
    retired effective September 30, 1995.
 
(2) The amounts reported as salary include director's fees and payments in  lieu
    of  director's fees  for each  of Messrs.  Liu, Fisher,  Root and  Males, of
    $11,200 in 1993, and accrued  vacation pay for Mr.  Root of $20,162 and  Mr.
    Males of $19,561 in 1995.
 
(3) The  amounts listed  represent plan year  awards pursuant  to the Management
    Incentive Compensation Plan, IES's annual incentive plan, with cash  payment
    made  in the subsequent calendar year. The  amount reported as bonus for Mr.
    Hoffman includes a one-time payment of $185,000 when he commenced employment
    with Utilities.
 
(4) The 1995 amounts shown as  Other Annual compensation represent the  earnings
    for  the Key Employee  Deferred Compensation Plan  in excess of  120% of the
    applicable federal  long-term rate  provided under  Section 1274(d)  of  the
    Code.  Also included are  relocation and moving expenses  for Mr. Hoffman in
    the amount of $51,523.
 
(5) The awards of restricted stock have been  made on June 1st since 1988,  with
    one-third  of  the  award being  restricted  for one  year,  one-third being
    restricted for two years and one-third being restricted for three years. The
    shares  of  restricted  stock  reflected  in  this  table  subject  to  such
 
                                      145
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
    three-year  vesting schedule for Messrs. Liu,  Fisher, Root and Franz are as
    follows: Mr. Liu --  6,171 shares in  1995; 8,315 shares  in 1994 and  5,670
    shares in 1993; Mr. Fisher -- 3,929 shares in 1994 and 2,705 shares in 1993;
    Mr.  Root -- 3,699 shares in 1994 and 2,547 shares in 1993; and Mr. Franz --
    1,467 shares in  1995, 1,380 shares  in 1994  and 1,046 shares  in 1993.  In
    addition,  in June 1993  Mr. Liu received  a grant of  4,000 shares, in June
    1994 Mr. Liu received a grant of  3,000 shares and in December 1995 Mr.  Liu
    received  a grant of 4,000 shares, all  of which will vest at retirement. In
    June 1995, Mr. Franz received a grant of 10,000 shares. The restrictions  on
    1,000  shares  will  lapse  each  year  beginning  in  June  1996  with  the
    restrictions on the  remainder lapsing at  retirement but not  prior to  Mr.
    Franz  becoming age  60. On May  31, 1996,  Mr. Hoffman received  a grant of
    5,000 shares as set  forth in his offer  of employment letter. These  shares
    are  in lieu of  any award for  1995 under the  long-term incentive plan but
    they have the  same restrictions as  if awarded under  the plan.  Restricted
    stock  is considered outstanding  upon award date and  dividends are paid to
    the eligible officers on these shares while restricted. The amounts shown in
    the table above represent the value  of the awards based upon closing  price
    of  IES Common Stock  on the award date.  The award date  is in the calendar
    year following the plan  year. Messrs. Fisher and  Root did not receive  any
    awards in 1996 since they are no longer IES employees. At December 31, 1995,
    the  listed officers  had restricted  stock for  which restrictions  had not
    lapsed (based upon the December 29, 1995 closing price of IES Common  Stock)
    as follows:
 
<TABLE>
<CAPTION>
                                                                SHARES       VALUE
                                                               ---------  -----------
<S>                                                            <C>        <C>
Lee Liu                                                           27,761  $   735,667
Blake O. Fisher, Jr.                                               6,084      161,226
James E. Hoffman                                                  --          --
Larry D. Root                                                      5,700      151,050
John F. Franz, Jr.                                                12,160      322,240
Rene H. Males                                                     --          --
</TABLE>
 
No stock options or stock appreciation rights have been awarded to the Executive
Officers listed above.
 
(6) Amounts shown for 1995 represent: (a) contributions by IES to the applicable
    employee  savings  plan in  the following  amounts: Mr.  Liu --  $4,648, Mr.
    Fisher -- $4,436, Mr. Root -- $4,210,  Mr. Franz -- $2,730 and Mr. Males  --
    $3,063;  (b) amount included in W-2  earnings for life insurance coverage in
    excess of $50,000 in the following amounts: Mr. Liu -- $8,859, Mr. Fisher --
    $2,509, Mr. Hoffman - $324,  Mr. Root - $3,168, Mr.  Franz - $2,163 and  Mr.
    Males  -  $3,286; (c)  severance pay  to be  paid in  1996 in  the following
    amounts: Mr. Root - $200,660 and Mr. Males - $332,180; and (d)  supplemental
    retirement pay of $19,715 for Mr. Males.
 
                                      146
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
                               PERFORMANCE GRAPH
 
    The graph below compares the total return to shareholders of IES versus that
for  the S&P 500 and  IES's peer group. Peer  companies were identified based on
revenue size,  sources  of  revenue, geographic  location,  markets  served  and
comparable  operations.  The following  17 companies  comprise IES's  peer group
(Iowa-Illinois  Gas  and  Electric  Company  and  Midwest  Resources  Inc.  have
individually  been omitted  from this year's  peer group because  they merged to
form MidAmerican Energy Company):
 
<TABLE>
<S>                                        <C>
CIPSCO Inc.                                MDU Resources Group, Inc.
CILCORP Inc.                               MidAmerican Energy Company
DPL Inc.                                   Minnesota Power and Light Company
IPALCO Enerprises Inc.                     Southwestern Public Service Company
Illinois Power Company                     UtiliCorp United Inc.
IPC                                        WPLH
KU Energy Corp.                            Wisconsin Energy Corporation
Kansas City Power and Light Company        Wisconsin Public Service Corporation
LG&E Energy Corp.
</TABLE>
 
                              IES INDUSTRIES INC.
                COMPARISON OF FIVE-YEAR CUMULATIVE TOTAL RETURN
 
                                    [CHART]
- ------------------------
* IES and Peer Group Index total returns include dividends compounded  annually.
  The companies comprising the Peer Group Index are identified above.
 
<TABLE>
<CAPTION>
                                     1990       1991       1992       1993       1994       1995
                                   ---------  ---------  ---------  ---------  ---------  ---------
<S>                                <C>        <C>        <C>        <C>        <C>        <C>
IES Industries Inc.                $  100.00  $  117.87  $  136.68  $  154.52  $  135.24  $  153.18
Peer Group Index                   $  100.00  $  133.77  $  142.75  $  156.01  $  148.80  $  189.24
S&P 500                            $  100.00  $  130.57  $  140.60  $  154.64  $  156.64  $  215.49
</TABLE>
 
    Total  returns for each peer company  were determined in accordance with the
Securities and Exchange Commission regulations, I.E., weighted according to each
company's stock market capitalization.
 
                                      147
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
                                   IES PLANS
 
    IES PENSION  PLANS:   IES, Utilities  and  the Cedar  Rapids and  Iowa  City
Railway  Company have  non-contributory retirement plans  covering employees who
have at least one year of accredited service. Directors who are not officers  do
not  participate in  the plans.  Maximum annual  benefits payable  at age  65 to
participants who retire  at age  65, calculated on  the basis  of straight  life
annuity, are illustrated in the following table:
 
                               PENSION PLAN TABLE
 
<TABLE>
<CAPTION>
   AVERAGE OF HIGHEST
         ANNUAL           ESTIMATED MAXIMUM ANNUAL RETIREMENT BENEFITS BASED ON
 SALARY (REMUNERATION)                        SERVICE YEARS
   FOR 3 CONSECUTIVE      -----------------------------------------------------
  YEARS OF THE LAST 10       15         20         25         30         35
- ------------------------  ---------  ---------  ---------  ---------  ---------
<S>                       <C>        <C>        <C>        <C>        <C>
     125,000.....            27,119     36,158     45,198     54,237     63,277
     150,000.....            32,931     43,908     54,885     65,862     76,839
     175,000.....            36,941     49,460     61,980     74,499     87,018
     200,000.....            41,816     56,210     70,605     84,999     99,393
     225,000.....            46,691     62,960     79,230     95,499    111,768
     250,000.....            47,466     64,033     80,600     97,168    113,735
     300,000.....            47,466     64,033     80,600     97,168    113,735
     400,000.....            47,466     64,033     80,600     97,168    113,735
     450,000.....            47,466     64,033     80,600     97,168    113,735
     500,000.....            47,466     64,033     80,600     97,168    113,735
</TABLE>
 
    For  1995, $120,000 is  the maximum benefits  allowable under the retirement
plans prescribed by Section 415 of the Code.
 
    With respect to the  officers named in the  Summary Compensation Table,  the
remuneration  for retirement  plan purposes would  be substantially  the same as
that shown as  "Salary." As of  December 31, 1995,  the officers had  accredited
years of service for the retirement plan as follows: Lee Liu, 38 years; Blake O.
Fisher,  Jr., 5 years; James  E. Hoffman, 0 years; Larry  D. Root, 25 years; and
John F. Franz, Jr., 4 years.
 
    SUPPLEMENTAL  RETIREMENT  PLANS:    IES  has  a  non-qualified  Supplemental
Retirement  Plan for eligible  officers of IES  and Utilities, including Messrs.
Hoffman and  Franz. The  plan provides  for payment  of supplemental  retirement
benefits  equal to  69% of the  officer's base salary  in effect at  the date of
retirement, reduced by benefits receivable under the qualified retirement  plan,
for  a period not  to exceed 18 years  following the date  of retirement. In the
event of the death of the officer following retirement, similar payments reduced
by the joint and survivor annuity of the qualified retirement plan will be  made
to  his designated beneficiary (surviving spouse or dependent children), if any,
for a period not to exceed 12  years from the date of the officer's  retirement.
Thus,  if  an  officer  died  12  years  after  retirement,  no  payment  to the
beneficiary would be made. Death  benefits are provided on  the same basis to  a
designated  beneficiary for  a period not  to exceed  12 years from  the date of
death should the officer  die prior to  retirement. The Supplemental  Retirement
Plan  further provides  that if,  at the time  of the  death of  an officer, the
officer is  entitled to  receive,  is receiving,  or has  received  supplemental
retirement  benefits by virtue of having taken retirement, a death benefit shall
be paid to the officer's designated beneficiary or to the officer's estate in an
amount equal to 100%  of the officer's  annual salary in effect  at the date  of
retirement.  Under certain circumstances, an  officer who takes early retirement
will be entitled to reduced benefits under the Supplemental Retirement Plan. The
Supplemental Retirement Plan also provides for benefits in the event an  officer
becomes  disabled  under the  terms of  the qualified  retirement plan.  IES has
purchased life insurance on the participants
 
                                      148
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
sufficient in amount to finance actuarially all of its future liabilities  under
the  Supplemental Retirement Plan  and IES is  the owner and  beneficiary of all
such life insurance. The Supplemental Retirement Plan has been designed so  that
if  the  assumptions made  as to  mortality,  experience, policy  dividends, tax
credits and  other factors  are realized,  IES  will fully  recover all  of  its
premium payments over the life of the Supplemental Retirement Plan.
 
    The  following table shows  the estimated annual  benefits payable under the
Supplemental Retirement Plan equal to 69% of the officers base salary in  effect
at the date of retirement:
 
                              IES INDUSTRIES INC.
                     SUPPLEMENTAL RETIREMENT PLAN PAYMENTS
                                69% SRP BENEFIT
 
<TABLE>
<CAPTION>
                                      SERVICE YEARS
  FINAL ANNUAL    -----------------------------------------------------
     SALARY          15         20         25         30         35
- ----------------  ---------  ---------  ---------  ---------  ---------
<S>               <C>        <C>        <C>        <C>        <C>
  125,000....        59,131     50,092     41,052     32,013     22,973
  150,000....        70,569     59,592     48,615     37,638     26,661
  175,000....        83,809     71,290     58,770     46,251     33,732
  200,000....        96,184     81,790     67,395     53,001     38,607
  225,000....       108,559     92,290     76,020     59,751     43,482
  250,000....       125,034    108,467     91,900     75,332     58,765
  300,000....       159,534    142,967    126,400    109,832     93,265
  400,000....       228,534    211,967    195,400    178,832    162,265
  450,000....       263,034    246,467    229,900    213,332    196,765
  500,000....       297,534    280,967    264,400    247,832    231,265
</TABLE>
 
    Mr.  Liu has elected to continue under the supplemental retirement agreement
previously provided to him by IES with provisions for payment of benefits  equal
to  75%  of the  officer's base  salary, for  a  period not  to exceed  15 years
following the  date  of retirement,  and  payment  to the  surviving  spouse  or
dependent  children for a  period not to  exceed 10 years  following the date of
retirement.
 
    The following table shows  the estimated annual  benefits payable under  the
Supplemental Retirement Plan equal to 75% of the officer's base salary in effect
at the date of retirement:
 
                              IES INDUSTRIES INC.
                     SUPPLEMENTAL RETIREMENT PLAN PAYMENTS
                                75% SRP BENEFIT
 
<TABLE>
<CAPTION>
                                      SERVICE YEARS
  FINAL ANNUAL    -----------------------------------------------------
     SALARY          15         20         25         30         35
- ----------------  ---------  ---------  ---------  ---------  ---------
<S>               <C>        <C>        <C>        <C>        <C>
      125,000        66,631     57,592     48,552     39,513     30,473
      150,000        79,569     68,592     57,615     46,638     35,661
      175,000        94,309     81,790     69,270     56,751     44,232
      200,000       108,184     93,790     79,395     65,001     50,607
      225,000       122,059    105,790     89,520     73,251     56,982
      250,000       140,034    123,467    106,900     90,332     73,765
      300,000       177,534    160,967    144,400    127,832    111,265
      400,000       252,534    235,967    219,400    202,832    186,265
      450,000       290,034    273,467    256,900    240,332    223,765
      500,000       327,534    310,967    294,400    277,832    261,265
</TABLE>
 
    Mr.  Males  retired  under a  supplemental  retirement  agreement previously
provided to him by Iowa Southern  Utilities Company with provisions for  payment
of  benefits equal  to 65% of  base salary  for life, subject  to consumer price
index adjustment, and  payments to survivors  after death of  the officer for  a
period not to exceed 15 years following the date of retirement.
 
                                      149
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
    The  following table shows  the estimated annual  benefits payable under the
Supplemental Retirement Plan equal to 65% of the officer's base salary in effect
at the date of retirement:
 
                              IES INDUSTRIES INC.
                     SUPPLEMENTAL RETIREMENT PLAN PAYMENTS
                                65% SRP BENEFIT
 
<TABLE>
<CAPTION>
                                      SERVICE YEARS
  FINAL ANNUAL    -----------------------------------------------------
     SALARY          15         20         25         30         35
- ----------------  ---------  ---------  ---------  ---------  ---------
<S>               <C>        <C>        <C>        <C>        <C>
      125,000        54,131     45,092     36,052     27,013     17,973
      150,000        64,569     53,592     42,615     31,638     20,661
      175,000        76,809     64,290     51,770     39,251     26,732
      200,000        88,184     73,790     59,395     45,001     30,607
      225,000        99,559     83,290     67,020     50,751     34,482
      250,000       115,034     98,467     81,900     65,332     48,765
      300,000       147,534    130,967    114,400     97,832     81,265
      400,000       212,534    195,967    179,400    162,832    146,265
      450,000       245,034    228,467    211,900    195,332    178,765
      500,000       277,534    260,967    244,400    227,832    211,265
</TABLE>
 
    EXECUTIVE GUARANTY PLAN:  The IES  Board has approved an Executive  Guaranty
Plan  (the "Guaranty  Plan") for officers  of IES and  its principal subsidiary,
Utilities. The  purpose  of the  Guaranty  Plan  is to  promote  flexibility  in
financial planning of participating officers and to provide an inducement to new
officers  in order to retain and  attract the best possible executive management
team. Under the Guaranty Plan, IES guarantees loans within defined limits, based
on salary level and years of service made to participating officers for  various
specified  purposes,  including real  estate acquisitions  and purchases  of IES
Common Stock.  As of  December  31, 1995,  guarantees  of $76,653,  $49,125  and
$50,000, were outstanding for Messrs. Liu, Root and Fisher, respectively.
 
    EXECUTIVE  CHANGE OF CONTROL AGREEMENTS:   IES has severance agreements with
twelve of its executives, including Messrs.  Liu, Hoffman and Franz. Mr.  Fisher
had  a severance  agreement with  IES which  is described  in this  section. The
severance agreements run for terms of one  year (three years in the case of  Mr.
Liu),  subject to  automatic renewal  unless either  party gives  notice of non-
renewal to the other party  at least 60 days prior  to the annual renewal  date.
Each  agreement provides for  salary continuation and  certain other benefits in
the event  the  covered  executive  is terminated  within  a  three-year  period
following  a change of control of IES. For these purposes, a "change of control"
is described  in the  IES  Charter and,  in addition,  will  be deemed  to  have
occurred,  if following a merger, consolidation or reorganization, the owners of
the capital stock entitled to vote in the election of directors of IES prior  to
the  transaction own  less than  75% of the  resulting entity's  voting stock or
during any period of two consecutive years, individuals who, at the beginning of
such period constitute the Board of  Directors of the parent company, cease  for
any  reason to constitute at  least a majority of the  Board of Directors of any
successor organization. Accordingly,  the Mergers  will constitute  a change  of
control  for purposes of each of the IES severance agreements. Specifically, the
agreements  provide  that  following   termination  of  a  covered   executive's
employment, except terminations for just cause, death, retirement, disability or
voluntary   resignation  (other   than  resignation  for   "good  reason"),  the
executive's salary will be continued, at a level equal to his salary just  prior
to  termination,  for  a  period  ranging  from  eighteen  to  thirty-six months
(depending on the executive  involved and, in certain  cases, his/her length  of
service). Additionally, certain benefits will be continued during the applicable
severance  period, including life  and health insurance,  and the executive will
continue to receive annual incentive award payments equal to the average  annual
incentive awards paid to executives of the same or comparable designation during
the  three years prior to the change of control. In the event the executive dies
during the severance  period, the  salary and benefit  payments described  above
shall  be payable during the remainder of  the term to the executive's surviving
spouse or his  estate. The  executive will  also become  immediately vested  and
entitled to receive awards of
 
                                      150
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
restricted  stock or other rights granted to the executive under IES's Long-Term
Incentive Plan. With respect to  a covered executive who is  age 56 or older  at
the time of the change of control, the severance agreement further provides that
the  change of control  will cause the  executive to become  fully vested in his
supplemental retirement  plan benefit  ("SERP"), and  that if  the executive  is
terminated  within three years following the change  of control, he will be able
to commence his SERP payments  on the earlier of the  date he attains age 65  or
the date salary continuation payments cease under his severance agreement.
 
    In  November 1995, IES approved certain amendments to the existing severance
agreements which will take effect no later than the next annual renewal of  each
agreement,  subject  to  each  executive's  execution  of  an  amended  form  of
agreement. The amendments to the severance agreements for Messrs. Liu and Fisher
provide, among other things, that during the applicable severance period Messrs.
Liu and Fisher will be entitled to  receive payments equal to the average  value
of  both the long-term and the annual incentive awards received by executives of
the same or comparable designation during the three years prior to the change of
control.  In  addition,  the  amendments  for  all  covered  executives  provide
reimbursement,  in an amount not  to exceed 15% of  the executive's base salary,
for outplacement services and legal fees incurred by the executive in connection
with his  termination, and  also  provide severance  benefits  in the  event  of
certain employment terminations within 180 days prior to a change of control.
 
    The  provisions  of  the  severance  agreement  covering  Mr.  Liu  has been
incorporated into the Employment  Agreement to be executed  between Mr. Liu  and
Interstate Energy in connection with the Mergers (See "The Mergers -- Employment
Agreements"  and Annex  H). After the  Effective Time,  his Employment Agreement
will supersede his existing severance agreement.
 
    IES believes that these agreements enable  IES to employ key executives  who
can  approach major business decisions objectively and without concern for their
personal situations.
 
    TERMINATION OF EMPLOYMENT ARRANGEMENT:   Larry D.  Root, IES Executive  Vice
President,  elected to take early retirement  effective as of December 31, 1995,
following 25 years of service to IES. In connection with Mr. Root's  retirement,
IES  entered into an early retirement agreement with Mr. Root which, among other
things, provided for certain payments and other financial considerations.  Under
the terms of Mr. Root's early retirement agreement, IES paid Mr. Root a lump sum
cash  payment  of $200,660  on January  4,  1996. IES  agreed to  accelerate the
vesting of restricted stock grants previously  granted to Mr. Root so that  such
grants  became vested on  December 31, 1995.  IES also agreed  that Mr. Root was
eligible to receive an  award under the  Management Incentive Compensation  Plan
for  1995 performance, which was awarded to him in February 1996. Mr. Root shall
receive, as an unfunded supplemental pension benefit, $11,306.11 per month for a
period of fifteen (15)  years. IES shall  also pay, within  three months of  Mr.
Root's  death, a death benefit of $200,660  to his beneficiaries. Mr. Root shall
be eligible  for the  medical  coverage generally  offered  by IES  to  retiring
employees,  in accordance with the  terms of the IES  Health Care Plan. Blake O.
Fisher, Jr., IES Executive  Vice President &  Chief Financial Officer,  resigned
from  IES  effective February  21,  1996. IES  and  Mr. Fisher  entered  into an
agreement which provided for certain payments and other financial considerations
as set forth in Mr. Fisher's  Executive Change of Control Agreement, details  of
which  are set forth in the section  above entitled "Executive Change of Control
Agreements."
 
                         IOWA SOUTHERN UTILITIES PLANS
 
    IOWA SOUTHERN  UTILITIES  PENSION PLAN:    Iowa Southern  Utilities  Company
("Iowa  Southern Utilities") provided a  contributory pension plan which covered
substantially all  non-collective bargaining  employees who  have completed  the
minimum  eligibility requirements of 1,000 hours in a year. The plan was amended
effective January  1, 1991  to  be non-contributory.  As  of his  retirement  on
September  30,  1995, Mr.  Males had  4  years of  accredited service  under the
Pension Plan. Participants contributed one percent of annual compensation to the
Pension Plan through 1990.
 
                                      151
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
    IOWA SOUTHERN UTILITIES SENIOR  EXECUTIVE SEVERANCE AGREEMENTS:   Individual
agreements  providing  for  severance pay  were  entered into  by  Iowa Southern
Utilities and four senior  executives, including Mr. Males.  The benefits to  be
provided  were generally as follows: a lump sum payment equal to the executive's
salary for a  payment period equal  to the greater  of 24 months,  or one  month
multiplied  by years of service with a limit of 30 months. Mr. Males's agreement
provides for  the greater  of  24 months  or the  period  between the  date  his
employment  terminates and  January 28, 1996.  In addition,  each covered senior
executive was entitled  to continuation  of life and  health insurance  coverage
during  the payment period and reimbursement of certain other expenses. The only
agreement still in effect in 1995 was with Mr. Males. Mr. Males' retirement  was
a  qualified termination  under the agreement.  Mr. Males  will receive payments
under the severance agreement beginning in 1996.
 
                              EMPLOYMENT AGREEMENT
 
    IE  Industries  Inc.  and  Iowa  Electric  Light  and  Power  Company,   the
predecessor   companies  of  IES  Industries  and  Utilities,  entered  into  an
employment agreement (the "Liu Agreement") with Lee Liu, which became  effective
July  1, 1991.  The Liu  Agreement provides  that Mr.  Liu shall  be employed as
President, Chief Executive Officer  and Chairman of  the Executive Committee  of
IES  and as Chief Executive Officer and  Chairman of Utilities from July 1, 1991
until April 1995, which period shall  be automatically extended unless at  least
six  months prior to any  expiration thereof either IES  or Utilities or Mr. Liu
shall give notice  that they do  not wish to  extend such time  (the "Period  of
Employment").  To date, neither  party has given such  notice. The Liu Agreement
also provides that he shall become Chairman of the Board at such time as  C.R.S.
Anderson  ceases to serve in  such position. This occurred  on July 1, 1993. The
Liu Agreement provides that Mr. Liu shall provide consulting services to IES for
three years ( the "Period of Consulting") after the conclusion of the Period  of
Employment.
 
    During  the Period of Employment, Mr. Liu  will be paid a base annual salary
of at  least $275,000,  and will  be entitled  to participate  in all  incentive
compensation  plans applicable to the positions  he holds and all retirement and
employee welfare  benefit plans.  During  the Period  of Employment,  Mr.  Liu's
incentive  compensation shall be at least equal  to that paid to the Chairman of
the Board of IES.
 
    If Mr.  Liu's  employment  is  terminated without  his  consent  by  IES  or
Utilities  during the Period of Employment for other than an unremedied material
breach or just cause or by his resignation if such resignation occurs after  IES
fails  to cause him to  be employed in or elected  to the positions specified in
the Liu Agreement or after a material diminution in his duties, responsibilities
or status, then Mr. Liu shall be entitled  to an amount equal to the sum of  his
base  annual salary  as of  the date of  termination plus  his average incentive
compensation  during  the  three  years   immediately  preceding  the  date   of
termination  multiplied  by the  number of  years  (and fractions  thereof) then
remaining in  the  Period of  Employment.  Mr. Liu  also  would be  entitled  to
continued  insurance coverages and an amount equal  to the then present value of
the actuarially determined difference between the aggregate retirement  benefits
actually  to be  received by him  as of the  date of termination  and those that
would have been  received by him  had he continued  to be employed  at the  base
salary  in  effect  at  termination  through the  expiration  of  the  Period of
Employment. All his shares of IES Restricted Stock would also vest at that time.
 
    During the Period of Consulting, Mr. Liu will make himself available for  up
to  30 days per year, report to the Chief Executive Officer of IES and will earn
an annual  consulting fee  equal to  13.33% of  his highest  annual base  salary
during his Period of Employment. If Mr. Liu's consulting services are terminated
for  reasons other than material breach or just  cause, he will be entitled to a
lump sum payment equal to  the amount of the  consulting fee he would  otherwise
have earned during the Period of Consulting.
 
                                      152
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IES PROXY STATEMENT]
 
    The  Employment  Agreement which  Mr. Liu  will  enter into  with Interstate
Energy in connection with the Mergers will supersede the Liu Agreement described
above. See "The Mergers -- Employment Agreements."
 
                              CERTAIN SEC FILINGS
 
    Section 16(a) of the Securities Exchange Act of 1934 requires IES's officers
and directors and persons who own more than 10% of the registered class of IES's
equity securities to file reports of ownership and changes in ownership with the
SEC. Such officers, directors and  shareholders are required by SEC  regulations
to furnish IES with copies of all such reports that they file.
 
    Based  solely  on a  review of  copies of  reports filed  with the  SEC with
respect  to  1995  and  of  written  representations  by  certain  officers  and
directors,  all persons subject  to the reporting  requirements of Section 16(a)
filed the required reports on a timely basis.
 
                         INDEPENDENT PUBLIC ACCOUNTANTS
 
    The Audit Committee recommended and the IES Board authorized the  engagement
of  Arthur Andersen LLP as auditors for  IES and its subsidiaries for 1996. They
have served as IES's auditors for 1995  and for many prior years. The IES  Board
believes  that because of the Audit Committee's direct and independent access to
both the internal  and independent  auditors and the  Audit Committee's  overall
responsibility  for audit  results and  supervision of  the auditors,  the Audit
Committee is best  suited to select  the independent auditor  and approve  audit
arrangements.  A representative of Arthur Andersen  LLP will be in attendance at
the IES Meeting and will be available to respond to appropriate questions and to
make a statement if he desires to do so.
 
                                    GENERAL
 
    A copy of the Annual Report  of IES, including financial statements for  the
fiscal year ended December 31, 1995, was previously mailed to shareholders.
 
                                      153
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
                           ELECTION OF IPC DIRECTORS
 
NOMINEES FOR DIRECTORS
 
    The  IPC  Board is  divided into  three classes  serving staggered  terms in
accordance with the  IPC Charter. The  number of directors,  in accordance  with
IPC's  By-Laws, constituting  the full  board of  directors shall  be seven. The
terms of Mr. James E. Byrns and Mr. Gerald L. Kopischke will expire at the  1996
annual  meeting and each has  been nominated for re-election  to a term of three
years expiring in  1999. In all  cases, the directors  elected will continue  to
serve  until  their  respective  successors shall  have  been  duly  elected and
qualified.
 
    It is intended that the proxies solicited on behalf of the IPC Board will be
voted for the Class II nominees, Mr. Byrns and Mr. Kopischke.
 
    In the event that either  of the nominees should  become unable or for  good
reason  will not serve  as a director, it  is intended that  the proxies will be
voted for the election of such other person or persons as shall be designated by
the IPC Board. It is not anticipated that either of the nominees will be  unable
or unwilling to serve as a director. Except as otherwise indicated, each nominee
has  been engaged in  his or her  present principal occupation  for at least the
past five years.
 
    The IPC Board recommends a vote FOR the nominees for director.
 
    Mr. Nicholas J. Schrup,  66, a member  of the IPC  Board since 1979,  passed
away on January 16, 1996.
 
    Following the untimely death of Mr. Schrup, Mr. Michael R. Chase was elected
to  the IPC Board effective January 26, 1996 to fill Mr. Schrup's unexpired term
as a Class III director.
 
    Biographical information concerning each of the nominees for re-election and
the directors continuing in office is presented on the following pages.
 
                                      136
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
                NOMINEES FOR DIRECTOR FOR TERMS EXPIRING IN 1999
       CLASS II DIRECTORS -- PRESENT TERMS EXPIRE AT 1996 ANNUAL MEETING
 
<TABLE>
<C>                  <S>
(Insert Photograph)  JAMES E. BYRNS, 69, is  Chairman and Chief Executive Officer  of
                     Custom-Pak,  Inc.  of  Clinton, Iowa,  a  firm of  which  he was
                     co-founder in 1974. Mr.  Byrns was elected  to this position  on
                     August  15, 1989.  He had been  President of  that Company since
                     1980 having served as Executive Vice President from 1974. He was
                     elected to  the IPC  Board on  January 31,  1984. Mr.  Byrns  is
                     Chairman  of the  Nominating Committee  and is  a member  of the
                     Audit Committee and the Compensation Committee.
 
(Insert Photograph)  GERALD L. KOPISCHKE, 64, was elected to the IPC Board  effective
                     July  10,  1992. Mr.  Kopischke  was elected  Vice  President --
                     Electric Operations on September 1,  1980 and retired from  that
                     position  on  January  1, 1996.  He  had served  as  Director of
                     Electrical  Engineering  prior  to   being  appointed  as   Vice
                     President.   Mr.  Kopischke  is  a   member  of  the  Nominating
                     Committee.
</TABLE>
 
                           OTHER INCUMBENT DIRECTORS
       CLASS III DIRECTORS -- PRESENT TERMS EXPIRE AT 1997 ANNUAL MEETING
 
<TABLE>
<C>                  <S>
(Insert Photograph)  ALAN B. ARENDS, 62, is President of Arends Associates, Inc.,  of
                     Albert  Lea, Minnesota,  an employee  benefits company  which he
                     founded in 1983.  Mr. Arends has  also taught at  both the  high
                     school  and college levels.  He was elected to  the IPC Board on
                     August 15,  1993. Mr.  Arends is  Chairman of  the  Compensation
                     Committee and is a member of the Audit Committee.
 
(Insert Photograph)  MICHAEL  R. CHASE,  57, was elected  to the  IPC Board effective
                     January 26,  1996. Mr.  Chase replaces  Nicholas J.  Schrup  who
                     passed away on January 16, 1996. Mr. Chase was elected Executive
                     Vice President on July 1, 1995. He had served as Director, Power
                     Generation  beginning  in 1988  and  then Vice  President, Power
                     Production on January 1, 1991.
 
(Insert Photograph)  WAYNE H. STOPPELMOOR, 62, was elected  to the IPC Board in  July
                     1986.  He  was  elected President  and  Chief  Executive Officer
                     effective January 1,  1987 and  was elected Chairman  on May  1,
                     1990.   Mr.  Stoppelmoor   had  served  as   Vice  President  of
                     Administration  beginning  in  1978  and  then  Executive   Vice
                     President  starting in May 1985.  Mr. Stoppelmoor is Chairman of
                     the Executive Committee.
</TABLE>
 
                                      137
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
        CLASS I DIRECTORS -- PRESENT TERMS EXPIRE AT 1998 ANNUAL MEETING
 
<TABLE>
<C>                  <S>
(Insert Photograph)  ALFRED D. CORDES, 64, was elected to the IPC Board on January 1,
                     1992. He was elected  Vice President -- District  Administration
                     and Public Affairs on May 1, 1990 and retired from that position
                     on  July 1,  1995. He  has also  served as  District Manager and
                     Executive Assistant prior to  being appointed Vice President  --
                     District  Administration  on January  1, 1986.  Mr. Cordes  is a
                     member of the Executive Committee and the Nominating Committee.
 
(Insert Photograph)  JOYCE L. HANES,  63, has  been a Director  of Midwest  Wholesale
                     Inc.,  Mason City, Iowa since 1970.  She was elected Chairman of
                     the Board of  that Company in  May, 1986 and  retired from  that
                     position in 1988. She was elected a Director of Interstate Power
                     Company  on January 1, 1982. Mrs. Hanes is Chairman of the Audit
                     Committee and is  a member  of the Executive  Committee and  the
                     Compensation Committee.
</TABLE>
 
    Certain  information  regarding  executive  officers of  IPC  called  for by
applicable regulations of the SEC has  been furnished in IPC's annual report  on
Form 10-K for 1995.
 
COMMITTEES OF THE IPC BOARD
 
    IPC has a standing Executive Committee, present members are Mr. Stoppelmoor,
Mr.  Cordes, and Mrs. Hanes. Prior to his death, Mr. Schrup was a member of this
committee. This committee held two meetings during the year 1995. The  functions
performed  by the Executive Committee include acting  on behalf of the IPC Board
when necessary between meetings of the full IPC Board.
 
    IPC has a  standing Audit  Committee, present  members are  Mrs. Hanes,  Mr.
Arends,  and Mr. Byrns.  The Audit Committee  held two meetings  during the year
1995. The functions performed were briefly  as follows: recommending to the  IPC
Board  the independent  auditors to  be employed  by IPC,  reviewing the planned
audit scope, reviewing the results of the independent auditors' examination  and
reporting  to the  IPC Board the  results of such  services with recommendations
concerning the same.
 
    IPC has a standing Nominating Committee, present members are Mr. Byrns,  Mr.
Kopischke,  and Mr. Cordes. The Nominating  Committee held two meetings in 1995.
The committee's function  is to make  recommendations to the  IPC Board for  IPC
Board  member succession,  and as  to the  IPC Board  member compensation. While
there are no formal procedures, the committee considers nominees brought to  its
attention  by  other  members  of  the  IPC  Board,  members  of  management and
shareowners.
 
    IPC has a standing Compensation  Committee, present members are Mr.  Arends,
Mr.  Byrns, and Mrs. Hanes. Prior to his  death, Mr. Schrup was a member of this
committee. The Compensation Committee's  functions are to  recommend to the  IPC
Board  the compensation of the CEO and  executive officers, the types and nature
of employee benefit plans,  and to prepare,  as required by  the Proxy Rules,  a
Compensation  Committee  report  to  be included  in  the  Proxy  Statement. The
Compensation Committee held one meeting during 1995.
 
    NOTE: The total number of meetings (of all kinds) of the IPC Board (together
with Committee meetings) during the fiscal year 1995 was 19. All directors  with
the  exception of Mr. Byrns, Mr. Cordes  and Mr. Schrup (deceased on January 16,
1996)   attended    all   of    the   meetings    of   the    IPC   Board    and
 
                                      138
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
committees  of the IPC Board  on which he or she  served. During 1995 Mr. Byrns,
Mr. Cordes and Mr. Schrup attended all but one of the total number of IPC  Board
meetings and Committee meetings on which they served.
 
COMPENSATION OF DIRECTORS
 
    During  the period of January  1, 1995 to March  31, 1995, all directors who
were not employees of  IPC were paid  $8,200.00 per year  plus $550.00 for  each
directors'  meeting  in  which they  participated.  Also $550.00  was  paid each
non-employee director for each committee meeting  held on a day separate from  a
scheduled  IPC Board meeting  while $275.00 was paid  for each committee meeting
which they attended that was  held the same day but  not in conjunction with  an
IPC Board meeting. Effective April 1, 1995, the annual retainer for non-employee
directors  was increased  to $8,500.00  per year.  The fees  for any  regular or
special meeting of the IPC Board as well as committee meetings held on non-board
meeting days were increased to $600. Fees for committee meetings held on an  IPC
Board  meeting day but not  consecutive of that meeting  were increased to $300.
The meeting and committee fees were for non-employee directors only.
 
    All directors who were not employees received reimbursement of out-of-pocket
expenses incurred  in connection  with directors'  or committee  meetings.  Each
director was included in IPC's group life insurance program.
 
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
 
    The IPC Board accepted the recommendations of the Compensation Committee for
the  1995 salaries  at the  December 8,  1994 IPC  Board meeting.  The following
interlocking and insider positions are required to be disclosed. Mr. Stoppelmoor
is an employee of IPC and serves on  the Board of Directors of American Trust  &
Savings  Bank. Mr. Schrup (deceased on January 16, 1996) who was on the Board of
Directors  of  American  Trust  &  Savings  Bank  was  the  Chairman  of   IPC's
Compensation Committee.
 
                     PRINCIPAL HOLDERS OF VOTING SECURITIES
 
SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS
 
    IPC  represents that as of June 20, 1996,  to the best of its knowledge only
the following persons or groups owned of record or beneficially more than 5%  of
the outstanding VOTING SECURITIES of IPC:
 
<TABLE>
<CAPTION>
                                                                     AMOUNT AND NATURE
                                                                       OF BENEFICIAL     % OF OWNERSHIP
NAME OF BENEFICIAL OWNER                        TITLE OF CLASS         OWNERSHIP (1)           (1)
- ------------------------------------------  -----------------------  ------------------  ---------------
<S>                                         <C>                      <C>                 <C>
WPLH                                        IPC Common Stock               1,903,293            16.6%
IES                                         IPC Common Stock               1,903,293            16.6%
</TABLE>
 
- ------------------------
(1) By reason of the Stock Option Agreements, each of WPLH and IES may be deemed
    to  have sole voting and dispositive power with respect to the shares listed
    above  which  are  subject  to  their  respective  Options  from  IPC   and,
    accordingly,  each of WPLH and IES may  be deemed to beneficially own all of
    such shares (assuming exercise  of its Option and  the nontriggering of  the
    other  party's right to exercise its  Option for IPC Common Stock). However,
    each of WPLH  and IES expressly  disclaim any beneficial  ownership of  such
    shares  because the Options  are exercisable only  in certain circumstances.
    See "The Stock Option Agreements."
 
SECURITY OWNERSHIP OF MANAGEMENT
 
    The directors and officers of IPC  owned of record and beneficially on  June
20,  1996 an aggregate of  32,198 shares of IPC  Common Stock, representing less
than 1% of the shares outstanding.
 
                                      139
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
    IPC represents  that as  of June  20, 1996,  to the  best of  its  knowledge
beneficial  ownership of shares of each class of EQUITY SECURITIES of IPC by all
directors and  nominees  individually,  the  CEO  and  certain  named  executive
officers  individually, and the directors  and officers of IPC  as a group is as
follows:
 
<TABLE>
<CAPTION>
                                                                                   AMOUNT AND NATURE
                                                                                     OF BENEFICIAL        % OF
NAME OF NOMINEE                                             TITLE OF CLASS (1)      OWNERSHIP (2)(3)   OWNERSHIP
- --------------------------------------------------------  -----------------------  ------------------  ----------
<S>                                                       <C>                      <C>                 <C>
Alan B. Arends                                                   IPC Common Stock           964            *
James E. Byrns                                                   IPC Common Stock         2,859            *
Michael R. Chase                                                 IPC Common Stock         5,251            *
Alfred D. Cordes                                                 IPC Common Stock         2,290(4)         *
Donald E. Hamill                                                 IPC Common Stock         2,257(4)         *
Joyce L. Hanes                                                   IPC Common Stock         1,652            *
Gerald L. Kopischke                                              IPC Common Stock         4,157(4)         *
Wayne H. Stoppelmoor                                             IPC Common Stock         4,698(4)         *
William C. Troy                                                  IPC Common Stock           310(4)         *
Officers and Directors as a group -- 14 in group                 IPC Common Stock        32,198(4)         *
</TABLE>
 
- ------------------------
 *  less than 1%
 
(1) In addition to IPC Common Stock, which is the only class of equity stock  of
    IPC which presently has voting power for the election of directors, IPC also
    has, as equity securities, outstanding shares of IPC Preferred Stock.
 
(2)  Information  with respect  to beneficial  ownership based  upon information
    furnished by each officer or director and contained in filings made with the
    SEC.
 
(3) Includes  shares in  which said  director or  officer may  have an  indirect
    beneficial  ownership by  reason of  the ownership  of such  shares by their
    spouses, dependent children or trusts.
 
(4) Includes 1,684 shares for Mr.  Stoppelmoor, 1,459 shares for Mr.  Kopischke,
    1,620  shares for Mr. Hamill, 999 shares  for Mr. Cordes, 215 shares for Mr.
    Troy and an  aggregate of 11,325  shares for officers  and directors.  These
    shares are in IPC's 401(k) Plan as of June 20, 1996.
 
                                      140
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
                COMPENSATION OF DIRECTORS AND EXECUTIVE OFFICERS
 
COMPENSATION COMMITTEE REPORT
 
    The  Compensation Committee consists of three members of the IPC Board (Mrs.
Hanes and Messrs. Arends and Schrup (deceased January 16, 1996) (Chairman)) none
of whom is a current or former officer or employee of IPC.
 
    Annually,  the  Committee  reviews   executive  compensation  to   determine
officers'  salary levels for the following year. The compensation of the CEO and
officers of IPC consists solely of base salary. The base salary levels for IPC's
CEO, Mr.  Stoppelmoor,  and executive  officers  are competitively  set  by  the
Committee  compared with  the base  salary levels  of similar  position in other
companies  of  similar  size  and  purpose.  Also,  considered  in  the   salary
determination is the individual officer's experience and performance relative to
IPC's  goals. It  is the aim  of the  Committee to determine  salary levels that
reward economic  value delivered  to IPC's  shareowners and  customers and  that
attract,  motivate, and retain executives of  the highest quality. As guidelines
in determining the  CEO and  officer salary  levels, the  Committee reviews  the
overall  corporate performance (including  earnings per share,  return on common
equity, operating expense, customer service, economic development and management
efficiency),  the  compensation  levels  of  comparable  utilities  and  general
industry and the salary recommendation of the Chief Executive Officer of IPC. Of
these  factors,  the Committee  accords significant  weight to  the compensation
levels of comparable utilities.
 
    During the discussion  of the  overall corporate performance,  it was  noted
that  for the  1994 year  the earnings, although  still low,  had increased. The
earnings were affected by a combination of unfavorable rate treatment,  abnormal
weather conditions, purchased power capacity payments, and environmental cleanup
costs. Operating efficiencies were improved through a consolidation of operating
districts.  IPC realized interest savings through the issuance of four series of
Pollution  Control  Refunding  Revenue  Bonds.  There  was  also  implemented  a
Strategic  Planning Study to review the  company's current and future long-range
goals in order to cut costs of operation.
 
    To determine equitable CEO and officer salary levels, the Committee reviewed
studies on executive  compensation in  non-manufacturing industries  as done  by
Ernst  and Young LLP and the Conference  Board, a list of salaries of executives
of the major publicly-held  companies doing business in  Iowa as published by  a
major  Iowa  newspaper,  and  a  similar  list  from  the  1994  Edison Electric
Institutes Executive Compensation Survey  of Chief Executive Officers  ("CEOs"),
more  specifically those companies west of  the Mississippi River plus Wisconsin
and Illinois that have revenues ranging from $89 million to $540 million. It has
been determined that Mr. Stoppelmoor's salary  should be aligned to the  average
total  cash  compensation  of  peer  CEOs of  the  utilities  surveyed  and then
internally each officer's salary would be set at a percentage of the CEOs.
 
    In setting 1995 salaries, the Committee considered the progress made  toward
corporate  goals of  company wide  cost containment  and the  establishment of a
strong record  in  the areas  of  customer service,  economic  development,  and
management  efficiency.  The Committee  recommended to  the IPC  Board executive
salaries consistent  with  the  range  of  average  estimated  salary  increases
throughout    the   comparable-size    utility   industry.    (The   Committee's
recommendations for 1995 officers' salaries were approved by the IPC Board.)
 
    In addition, on November 7, 1995 the Committee recommended to the IPC Board,
and the  IPC Board  subsequently adopted,  the IPC  Change-in-Control  Severance
Agreements  for  each of  nine of  IPC's  executive officers,  including Messrs.
Stoppelmoor,  Chase,  Hamill  and  Troy.   In  determining  to  recommend   such
agreements, the Committee concluded that it was in the best interests of IPC and
its  shareowners to foster the continued  employment of key executive personnel.
The Committee believes that the  IPC Change-in-Control Severance Agreements  are
an  appropriate  manner  in  which  to  reinforce  and  encourage  the continued
attention and  dedication of  IPC's key  executive personnel  to their  assigned
duties  without distraction in the  face of potentially disturbing circumstances
arising from a possible  change in control of  IPC. The Committee believes  that
the IPC Change-in-Control
 
                                      141
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
Severance  Agreements will  preserve the  interests of  shareowners by providing
certain financial  protections  for  senior  executive  officers  who  represent
important  assets of  IPC's business,  thus allowing  management objectivity and
continuity of operations in the event of, and after, a change in control of IPC.
 
                             Compensation Committee
 
   Nicholas J. Schrup, Chairman         Joyce L. Hanes        Alan B. Arends
   (deceased January 16, 1996)
 
PERFORMANCE GRAPH
 
                              INTERSTATE POWER COMPANY
          Comparison of Five Year Cumulative Total Return* Among IPC,
               Standard and Poor's Corporation (S & P) 500 Index
   & Edison Electric Institute (EEI) 100 Index of Investor Owned Electrics**
 
                                    [GRAPH]
Assumes $100 invested on January  1, 1991 in IPC Common  Stock, S & P 500  Index
and   EEI  100  Index  of  Investor  Owned  Electrics  *  Total  Return  Assumes
Reinvestment of Dividends **Fiscal Year Ending December 31.
 
<TABLE>
<CAPTION>
                                                                    1990       1991       1992       1993       1994       1995
                                                                  ---------  ---------  ---------  ---------  ---------  ---------
<S>                                                               <C>        <C>        <C>        <C>        <C>        <C>
Interstate Power Company                                          $     100  $     143  $     140  $     146  $     126  $     189
S&P 500 Index                                                     $     100  $     131  $     140  $     155  $     157  $     215
EEI 100 Index                                                     $     100  $     129  $     139  $     154  $     136  $     179
</TABLE>
 
                                      142
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
CASH COMPENSATION
 
    There is set forth below certain information concerning all compensation  of
the  CEO and the  four most highly  compensated executive officers  of IPC as to
whom the total compensation exceeded $100,000 during the year 1995.
 
SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
            NAME AND PRINCIPAL POSITION
- ----------------------------------------------------
                        (A)                                                       ANNUAL COMPENSATION
                                                      ---------------------------------------------------------------------------
                                                        YEAR     SALARY($)      BONUS         OTHER ANNUAL          ALL OTHER
                                                      ---------  ---------     ------         COMPENSATION       COMPENSATION($)
                                                         (B)      (C)(1)         (D)       -------------------  -----------------
                                                                                                   (E)               (I)(2)
 
<S>                                                   <C>        <C>        <C>            <C>                  <C>
Wayne H. Stoppelmoor                                       1995    260,000            0                 0                 250
 President & CEO                                           1994    245,000            0                 0                 250
                                                           1993    242,000            0                 0                   0
Gerald L. Kopischke                                        1995    168,500            0                 0                 250
 VP-Electric Operations                                    1994    160,000            0                 0                 250
                                                           1993    157,000            0                 0                   0
Michael R. Chase                                           1995    138,000            0                 0                 250
 VP-Power Production then Executive VP                     1994    123,500            0                 0                 250
 effective 07-01-95                                        1993    118,000            0                 0                   0
Donald E. Hamill                                           1995    123,000            0                 0                 250
 VP-Budgets/Regulatory Affairs                             1994    118,000            0                 0                 250
                                                           1993    116,000            0                 0                   0
William C. Troy                                            1995    123,000            0                 0                 250
 Controller                                                1994    118,000            0                 0                 250
                                                           1993    116,000            0                 0                   0
</TABLE>
 
- ------------------------
(1) Column (c) includes  any salary elective deferral  pursuant to IPC's  401(k)
    Plan. The 401(k) Plan is available to all employees.
 
(2)  Column (i)  includes any  company matching  funds pursuant  to IPC's 401(k)
    Plan. IPC matched $.25 on every dollar  deferred by the participant up to  a
    maximum match of $250. The option is available to all employees.
 
COMPENSATION PURSUANT TO PLANS
 
    IPC's  Pension Plan  covers substantially all  employees including officers.
Pension Plan  benefits  depend upon  credited  service, age  at  retirement  and
compensation.  At an assumed retirement age of 65, the normal retirement benefit
for Pension Plan participants  is based on  a formula that  applies a factor  of
1.17%  to the  participant's average  annual compensation  for the  four highest
consecutive  years  plus  a  factor   of  .35%  to  the  participant's   average
compensation in excess of social security covered compensation multiplied by the
number of accredited service years (maximum 35). Optional benefit forms are also
available.
 
    The  following table displays the maximum annual retirement benefits payable
under the straight life annuity form of pension at the normal retirement age  of
65  for  specified remunerations  and years  of service  under the  Pension Plan
provisions in effect December 31, 1995.
 
<TABLE>
<CAPTION>
                                                          ESTIMATED ANNUAL BENEFITS FOR YEARS OF SERVICE
                                                                              LISTED
    AVERAGE ANNUAL COMPENSATION FOR 4 HIGHEST PAID      --------------------------------------------------
                  CONSECUTIVE YEARS                      20 YEARS     25 YEARS     30 YEARS     35 YEARS
- ------------------------------------------------------  -----------  -----------  -----------  -----------
<S>                                                     <C>          <C>          <C>          <C>
$100,000                                                 $  28,586    $  35,732    $  42,878    $  50,025
 125,000                                                    36,186       45,232       54,278       63,325
 150,000                                                    43,786       54,732       65,678       76,625
 175,000 or greater                                         43,786*      54,732*      65,678*      76,625*
</TABLE>
 
*    1995 maximum allowable by current law.
 
                                      143
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
    For purposes of determining Pension Plan benefits, compensation for each  of
the  individuals listed  in the  Summary Compensation Table  is the  same as the
amounts set forth in  that table. The estimated  full years of credited  service
for  benefits at retirement under the  Pension Plan for those executive officers
listed in the Summary  Compensation Table are: Wayne  H. Stoppelmoor, 35  years;
Gerald  L. Kopischke, 35 years; Michael R. Chase, 35 years; Donald E. Hamill, 35
years; and William C. Troy, 25 years.
 
    In addition to the  Pension Plan, the  Supplemental Retirement Plan  ("SRP")
amended  in 1995 provides a supplemental retirement benefit for certain officers
of IPC who meet Plan requirements. The Plan presently covers the President,  all
Vice  Presidents, the Controller, the Secretary and Treasurer, and the Assistant
Secretary and Assistant Treasurer ("certain executive officers"). Benefits begin
at the  normal  retirement  date  (age  65)  or  a  participant  electing  early
retirement  may begin receiving reduced  benefits as early as  age 55. For those
certain executive officers  retiring on or  after January 1,  1994, the SRP  (1)
provides  a retirement  benefit per month  equal to seventy-five  percent of the
individual's highest average monthly salary for any consecutive 12-month  period
of employment by Interstate prior to retirement, less the individual's qualified
defined  benefit  retirement  plan  benefit  and  less  the  individual's social
security benefit, and (2) provides a survivor benefit. The SRP may be funded  in
part from the general assets of IPC in addition to the purchase of cost recovery
life insurance policies by IPC.
 
    The  following  table displays  the  maximum annual  supplemental retirement
benefits payable under the straight life  annuity form of pension at the  normal
retirement  age of  65 for  specified remunerations  for the  year of retirement
under the SRP provisions in effect at December 31, 1995.
 
           ESTIMATED ANNUAL SRP BENEFITS FOR YEARS OF SERVICE LISTED
 
<TABLE>
<CAPTION>
FINAL ANNUAL SALARY                                    20 YEARS     25 YEARS     30 YEARS     35 YEARS
- ----------------------------------------------------  -----------  -----------  -----------  -----------
<S>                                                   <C>          <C>          <C>          <C>
$125,000                                              $    44,364  $    35,318  $    26,272  $    17,225
 150,000                                                   55,514       44,568       33,622       22,675
 175,000                                                   74,264       63,318       52,372       41,425
 200,000                                                   93,014       82,068       71,122       60,175
 225,000                                                  111,764      100,818       89,872       78,925
 250,000                                                  130,514      119,568      108,622       97,675
 275,000                                                  149,264      138,318      127,372      116,425
 300,000                                                  168,014      157,068      146,122      135,175
 325,000                                                  186,764      175,818      164,872      153,925
</TABLE>
 
    IPC has  an Amended  Deferred Compensation  Plan available  to officers  and
non-employee  directors  and provides  for deferral  of  salaries and  fees with
accrued interest.
 
    In 1988,  IPC adopted  a  401(k) Plan  in which  all  employees of  IPC  are
eligible to participate, subject to meeting Plan eligibility requirements. Under
the provisions of this Plan, any eligible employee may elect to direct up to 15%
of  his or her compensation, as defined  in the Plan with a maximum contribution
of $9,240 for the year  1995. Any amount so deferred  by the employee is  exempt
from  current  federal  income tax.  Directors  who  are not  employees  are not
eligible to participate in  the Plan. To encourage  participation in this  Plan,
IPC  contributes to the account of participating employees 25 cents for each one
dollar contributed by  the employee,  up to  a maximum  Company contribution  of
$250.  Upon retirement from IPC, employees  may receive distributions from their
account held by the Plan Trustee.
 
OTHER COMPENSATION
 
    No officer  individually  or officers  as  a group  received  "Other  Annual
Compensation"  of $50,000 or 10% of the salary and bonus reported in the Summary
Compensation Table.
 
                                      144
<PAGE>
                                               [ALTERNATE PAGE FOR
                                              IPC PROXY STATEMENT]
 
STOCK OPTION AND STOCK APPRECIATION RIGHT PLANS
 
    No director or Officer of IPC  held any options to purchase securities  from
IPC or its subsidiary during the year 1995.
 
TERMINATION OF EMPLOYMENT AND CHANGE IN CONTROL ARRANGEMENTS
 
    IPC  has entered into the IPC Severance  Agreements with each of nine senior
executives of IPC (including Messrs. Stoppelmoor, Chase, Hamill and Troy)  which
generally  provide for certain benefits in the event the executive is terminated
or resigns under certain circumstances following a change in control of IPC  (as
defined  in the agreements). The Mergers will  constitute a change in control of
IPC for purposes of these agreements. For a more complete description of the IPC
Severance Agreements, see "The  Mergers -- Interests of  Certain Persons in  the
Mergers -- Severance Arrangements."
 
EMPLOYMENT AGREEMENTS
 
    Pursuant to the Merger Agreement, it is anticipated that IPC will enter into
an  employment agreement with  Mr. Chase following  consummation of the Mergers.
See "The Mergers -- Employment Agreements."
 
                 RELATIONSHIP WITH INDEPENDENT PUBLIC AUDITORS
 
    The firm  of  Deloitte &  Touche  LLP has  been  selected to  serve  as  the
independent  auditors for IPC  for the fiscal  year ending December  31, 1996. A
representative of Deloitte & Touche LLP is expected to be present at the  annual
meeting  of  shareowners  of  IPC  scheduled  for  September  5,  1996  with the
opportunity to make a  statement and to be  available to respond to  appropriate
questions.
 
                                      145
<PAGE>
                                                                         ANNEX A
 
                    AGREEMENT AND PLAN OF MERGER, AS AMENDED
 
                                  BY AND AMONG
 
                              WPL HOLDINGS, INC.,
 
                              IES INDUSTRIES INC.,
 
                            INTERSTATE POWER COMPANY
                           (A DELAWARE CORPORATION),
 
                              WPLH ACQUISITION CO.
 
                                      AND
 
                            INTERSTATE POWER COMPANY
                           (A WISCONSIN CORPORATION)
 
                         DATED AS OF NOVEMBER 10, 1995
 
                                      A-1
<PAGE>
                               TABLE OF CONTENTS
<TABLE>
<S>      <C>     <C>        <C>                                                                <C>
                                             ARTICLE I
 
                                            THE MERGER
 
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
Section     1.1  The Merger..................................................................  A-12
Section     1.2  Effects of the Merger.......................................................  A-13
Section     1.3  Effective Time of the Merger................................................  A-14
 
                                            ARTICLE II
 
                                        TREATMENT OF SHARES
 
Section     2.1  Effect of the Merger on Capital Stock.......................................  A-14
                 (a)        Cancellation of Certain Common Stock.............................  A-14
                 (b)        Conversion of Certain Common Stock...............................  A-14
                 (c)        Interstate Preferred Stock.......................................  A-15
                 (d)        Conversion of Acquisition Common Stock...........................  A-15
                 (e)        Redemption of Utilities Preferred Stock..........................  A-16
Section     2.2  Dissenting Shares...........................................................  A-16
Section     2.3  Issuance of New Certificates................................................  A-16
                 (a)        Deposit with Exchange Agent......................................  A-16
                 (b)        Issuance Procedures..............................................  A-16
                 (c)        Distributions with Respect to Unsurrendered Shares...............  A-17
                 (d)        No Fractional Securities.........................................  A-17
                 (e)        Closing of Common Stock Transfer Books...........................  A-18
                 (f)        Termination of Exchange Agent....................................  A-18
 
                                            ARTICLE III
 
                                            THE CLOSING
 
Section     3.1  The Closing.................................................................  A-18
 
                                            ARTICLE IV
 
                               REPRESENTATIONS AND WARRANTIES OF WPL
 
Section     4.1  Organization and Qualification..............................................  A-18
Section     4.2  Subsidiaries................................................................  A-19
Section     4.3  Capitalization..............................................................  A-19
Section     4.4  Authority; Noncontravention; Statutory Approvals; Compliance................  A-20
                 (a)        Authority........................................................  A-20
                 (b)        Noncontravention.................................................  A-20
                 (c)        Statutory Approvals..............................................  A-21
                 (d)        Compliance.......................................................  A-21
Section     4.5  Reports and Financial Statements............................................  A-22
Section     4.6  Absence of Certain Changes or Events........................................  A-22
Section     4.7  Litigation..................................................................  A-23
Section     4.8  Registration Statement and Proxy Statement..................................  A-23
Section     4.9  Tax Matters.................................................................  A-23
                 (a)        Filing of Timely Tax Returns.....................................  A-23
                 (b)        Payment of Taxes.................................................  A-23
                 (c)        Tax Reserves.....................................................  A-23
                 (d)        Tax Liens........................................................  A-23
                 (e)        Withholding Taxes................................................  A-24
                 (f)        Extensions of Time for Filing Tax Returns........................  A-24
</TABLE>
 
                                      A-2
<PAGE>
<TABLE>
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
                 (g)        Waivers of Statute of Limitations................................  A-24
                 (h)        Expiration of Statute of Limitations.............................  A-24
                 (i)        Audit, Administrative and Court Proceedings......................  A-24
                 (j)        Powers of Attorney...............................................  A-24
                 (k)        Tax Rulings......................................................  A-24
                 (l)        Availability of Tax Returns......................................  A-24
                 (m)        Tax Sharing Agreements...........................................  A-24
                 (n)        Code Section 280G................................................  A-24
                 (o)        Liability for Others.............................................  A-24
Section     4.10 Employee Matters; ERISA.....................................................  A-25
                 (a)        Benefit Plans....................................................  A-25
                 (b)        Contributions....................................................  A-25
                 (c)        Qualification; Compliance........................................  A-25
                 (d)        Liabilities......................................................  A-25
                 (e)        Welfare Plans....................................................  A-25
                 (f)        Documents made Available.........................................  A-26
                 (g)        Payments Resulting from Merger...................................  A-26
                 (h)        Labor Agreements.................................................  A-26
Section     4.11 Environmental Protection....................................................  A-27
                 (a)        Compliance.......................................................  A-27
                 (b)        Environmental Permits............................................  A-27
                 (c)        Environmental Claims.............................................  A-27
                 (d)        Releases.........................................................  A-27
                 (e)        Predecessors.....................................................  A-27
                 (f)        Disclosure.......................................................  A-28
                            (i)  "Environmental Claim".......................................  A-28
                            (ii)  "Environmental Laws".......................................  A-28
                            (iii)  "Hazardous Materials".....................................  A-28
                            (iv)  "Release"..................................................  A-29
Section     4.12 Regulation as a Utility.....................................................  A-29
Section     4.13 Vote Required...............................................................  A-29
Section     4.14 Accounting Matters..........................................................  A-29
Section     4.15 Applicability of Certain Provisions of Wisconsin Law, Etc...................  A-29
Section     4.16 Opinion of Financial Advisor................................................  A-30
Section     4.17 Insurance...................................................................  A-30
Section     4.18 Ownership of IES and Interstate Common Stock................................  A-30
Section     4.19 WPL Rights Agreement........................................................  A-30
Section     4.20 Operations of Nuclear Power Plant...........................................  A-30
 
                                             ARTICLE V
 
                               REPRESENTATIONS AND WARRANTIES OF IES
 
Section     5.1  Organization and Qualification..............................................  A-30
Section     5.2  Subsidiaries................................................................  A-31
Section     5.3  Capitalization..............................................................  A-31
Section     5.4  Authority; Noncontravention; Statutory Approvals; Compliance................  A-32
                 (a)        Authority........................................................  A-32
                 (b)        Noncontravention.................................................  A-32
                 (c)        Statutory Approvals..............................................  A-33
                 (d)        Compliance.......................................................  A-33
Section     5.5  Reports and Financial Statements............................................  A-33
Section     5.6  Absence of Certain Changes or Events........................................  A-34
Section     5.7  Litigation..................................................................  A-34
Section     5.8  Registration Statement and Proxy Statement..................................  A-34
</TABLE>
 
                                      A-3
<PAGE>
<TABLE>
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
Section     5.9  Tax Matters.................................................................  A-35
                 (a)        Filing of Timely Tax Returns.....................................  A-35
                 (b)        Payment of Taxes.................................................  A-35
                 (c)        Tax Reserves.....................................................  A-35
                 (d)        Tax Liens........................................................  A-35
                 (e)        Withholding Taxes................................................  A-35
                 (f)        Extensions of Time for Filing Tax Returns........................  A-35
                 (g)        Waivers of Statute of Limitations................................  A-35
                 (h)        Expiration of Statute of Limitations.............................  A-35
                 (i)        Audit, Administrative and Court Proceedings......................  A-35
                 (j)        Powers of Attorney...............................................  A-35
                 (k)        Tax Rulings......................................................  A-35
                 (l)        Availability of Tax Returns......................................  A-35
                 (m)        Tax Sharing Agreements...........................................  A-36
                 (n)        Code Section 280G................................................  A-36
                 (o)        Liability for Others.............................................  A-36
Section     5.10 Employee Matters; ERISA.....................................................  A-36
                 (a)        Benefit Plans....................................................  A-36
                 (b)        Contributions....................................................  A-36
                 (c)        Qualification; Compliance........................................  A-36
                 (d)        Liabilities......................................................  A-36
                 (e)        Welfare Plans....................................................  A-36
                 (f)        Documents made Available.........................................  A-37
                 (g)        Payments Resulting from Merger...................................  A-37
                 (h)        Labor Agreements.................................................  A-37
Section     5.11 Environmental Protection....................................................  A-38
                 (a)        Compliance.......................................................  A-38
                 (b)        Environmental Permits............................................  A-38
                 (c)        Environmental Claims.............................................  A-38
                 (d)        Releases.........................................................  A-38
                 (e)        Predecessors.....................................................  A-38
                 (f)        Disclosure.......................................................  A-39
Section     5.12 Regulation as a Utility.....................................................  A-39
Section     5.13 Vote Required...............................................................  A-39
Section     5.14 Accounting Matters..........................................................  A-39
Section     5.15 Applicability of Certain Iowa Law...........................................  A-39
Section     5.16 Opinion of Financial Advisor................................................  A-39
Section     5.17 Insurance...................................................................  A-39
Section     5.18 Ownership of WPL and Interstate Common Stock................................  A-39
Section     5.19 IES Rights Agreement........................................................  A-40
Section     5.20 Operations of Nuclear Power Plant...........................................  A-40
 
                                            ARTICLE VI
 
                           REPRESENTATIONS AND WARRANTIES OF INTERSTATE
 
Section     6.1  Organization and Qualification..............................................  A-40
Section     6.2  Subsidiaries................................................................  A-40
Section     6.3  Capitalization..............................................................  A-41
Section     6.4  Authority; Noncontravention; Statutory Approvals; Compliance................  A-41
                 (a)        Authority........................................................  A-41
                 (b)        Noncontravention.................................................  A-42
                 (c)        Statutory Approvals..............................................  A-42
                 (d)        Compliance.......................................................  A-42
Section     6.5  Reports and Financial Statements............................................  A-43
</TABLE>
 
                                      A-4
<PAGE>
<TABLE>
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
Section     6.6  Absence of Certain Changes or Events........................................  A-43
Section     6.7  Litigation..................................................................  A-44
Section     6.8  Registration Statement and Proxy Statement..................................  A-44
Section     6.9  Tax Matters.................................................................  A-44
                 (a)        Filing of Timely Tax Returns.....................................  A-44
                 (b)        Payment of Taxes.................................................  A-44
                 (c)        Tax Reserves.....................................................  A-44
                 (d)        Tax Liens........................................................  A-44
                 (e)        Withholding Taxes................................................  A-44
                 (f)        Extensions of Time for Filing Tax Returns........................  A-45
                 (g)        Waivers of Statute of Limitations................................  A-45
                 (h)        Expiration of Statute of Limitations.............................  A-45
                 (i)        Audit, Administrative and Court Proceedings......................  A-45
                 (j)        Powers of Attorney...............................................  A-45
                 (k)        Tax Rulings......................................................  A-45
                 (l)        Availability of Tax Returns......................................  A-45
                 (m)        Tax Sharing Agreements...........................................  A-45
                 (n)        Code Section 280G................................................  A-45
                 (o)        Liability for Others.............................................  A-45
Section     6.10 Employee Matters; ERISA.....................................................  A-45
                 (a)        Benefit Plans....................................................  A-45
                 (b)        Contributions....................................................  A-46
                 (c)        Qualification; Compliance........................................  A-46
                 (d)        Liabilities......................................................  A-46
                 (e)        Welfare Plans....................................................  A-46
                 (f)        Documents made Available.........................................  A-46
                 (g)        Payments Resulting from Merger...................................  A-47
                 (h)        Labor Agreements.................................................  A-47
Section     6.11 Environmental Protection....................................................  A-47
                 (a)        Compliance.......................................................  A-47
                 (b)        Environmental Permits............................................  A-48
                 (c)        Environmental Claims.............................................  A-48
                 (d)        Releases.........................................................  A-48
                 (e)        Predecessors.....................................................  A-48
                 (f)        Disclosure.......................................................  A-48
Section     6.12 Regulation as a Utility.....................................................  A-48
Section     6.13 Vote Required...............................................................  A-49
Section     6.14 Accounting Matters..........................................................  A-49
Section     6.15 Applicability of Certain Delaware Law, Etc..................................  A-49
Section     6.16 Opinion of Financial Advisor................................................  A-49
Section     6.17 Insurance...................................................................  A-49
Section     6.18 Ownership of WPL and IES Common Stock.......................................  A-49
</TABLE>
 
                                      A-5
<PAGE>
<TABLE>
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
                                            ARTICLE VII
 
                              CONDUCT OF BUSINESS PENDING THE MERGER
 
Section     7.1  Covenants of the Parties....................................................  A-49
Section     7.2  Ordinary Course of Business.................................................  A-49
Section     7.3  Dividends...................................................................  A-50
Section     7.4  Issuance of Securities......................................................  A-51
Section     7.5  Charter Documents...........................................................  A-52
Section     7.6  No Acquisitions.............................................................  A-52
Section     7.7  Capital Expenditures and Emission Allowances................................  A-52
Section     7.8  No Dispositions.............................................................  A-53
Section     7.9  Indebtedness................................................................  A-53
Section     7.10 Compensation, Benefits......................................................  A-53
Section     7.11 1935 Act....................................................................  A-53
Section     7.12 Transmission, Generation....................................................  A-54
Section     7.13 Accounting..................................................................  A-54
Section     7.14 Pooling.....................................................................  A-54
Section     7.15 Taxfree Status..............................................................  A-54
Section     7.16 Affiliate Transactions......................................................  A-54
Section     7.17 Cooperation, Notification...................................................  A-54
Section     7.18 Thirdparty Consents.........................................................  A-55
Section     7.19 No Breach...................................................................  A-55
Section     7.20 Taxexempt Status............................................................  A-55
Section     7.21 Transition Steering Team....................................................  A-55
Section     7.22 Company Actions.............................................................  A-55
Section     7.23 Tax Matters.................................................................  A-55
Section     7.24 Discharge of Liabilities....................................................  A-56
Section     7.25 Contracts...................................................................  A-56
Section     7.26 Insurance...................................................................  A-56
Section     7.27 Permits.....................................................................  A-56
 
                                           ARTICLE VIII
 
                                       ADDITIONAL AGREEMENTS
 
Section     8.1  Access to Information.......................................................  A-56
Section     8.2  Joint Proxy Statement and Registration Statement............................  A-57
                 (a)        Preparation and Filing...........................................  A-57
                 (b)        Letter of WPL's Accountants......................................  A-57
                 (c)        Letter of IES's Accountants......................................  A-57
                 (d)        Letter of Interstate's Accountants...............................  A-57
                 (e)        Fairness Opinions................................................  A-57
Section     8.3  Regulatory Matters..........................................................  A-58
                 (a)        HSR Filings......................................................  A-58
                 (b)        Other Regulatory Approvals.......................................  A-58
Section     8.4  Shareholder Approval........................................................  A-58
                 (a)        Approval of IES Shareholders.....................................  A-58
                 (b)        Approval of WPL Shareholders.....................................  A-58
                 (c)        Approval of Interstate Shareholders..............................  A-59
                 (d)        Meeting Date.....................................................  A-59
                 (e)        Fairness Opinions Not Withdrawn..................................  A-59
Section     8.5  Director and Officer Indemnification........................................  A-59
                 (a)        Indemnification..................................................  A-59
</TABLE>
 
                                      A-6
<PAGE>
<TABLE>
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
                 (b)        Insurance........................................................  A-60
                 (c)        Successors.......................................................  A-60
                 (d)        Survival of Indemnification......................................  A-60
                 (e)        Benefit..........................................................  A-60
Section     8.6  Disclosure Schedules........................................................  A-60
Section     8.7  Public Announcements........................................................  A-61
Section     8.8  Rule 145 Affiliates.........................................................  A-61
Section     8.9  Employee Agreements and Workforce Matters...................................  A-61
                 (a)        Certain Employee Agreements......................................  A-61
                 (b)        Workforce Matters................................................  A-61
Section     8.10 Employee Benefit Plans......................................................  A-62
Section     8.11 Stock Option and Other Stock Plans..........................................  A-62
                 (a)        Amendment of Stock Plans and Agreements..........................  A-62
                 (b)        Company Action...................................................  A-63
Section     8.12 No Solicitations............................................................  A-63
Section     8.13 Company Board of Directors..................................................  A-64
Section     8.14 Company Officers............................................................  A-65
Section     8.15 Employment Contracts........................................................  A-65
Section     8.16 PostMerger Operations.......................................................  A-65
Section     8.17 Expenses....................................................................  A-66
Section     8.18 Further Assurances..........................................................  A-66
Section     8.19 Charter and Bylaw Amendments................................................  A-66
Section     8.20 IES Rights Agreement........................................................  A-66
 
                                            ARTICLE IX
 
                                            CONDITIONS
 
Section     9.1  Conditions to each Party's Obligation to Effect the Merger..................  A-66
                 (a)        Shareholder Approvals............................................  A-66
                 (b)        No Injunction....................................................  A-67
                 (c)        Registration Statement...........................................  A-67
                 (d)        Listing of Shares................................................  A-67
                 (e)        Statutory Approvals..............................................  A-67
                 (f)        Pooling..........................................................  A-67
Section     9.2  Further Conditions to Obligation of IES to Effect the IES Merger............  A-67
                 (a)        Performance of Obligations.......................................  A-67
                 (b)        Representations and Warranties...................................  A-67
                 (c)        Closing Certificates.............................................  A-68
                 (d)        Material Adverse Effect..........................................  A-68
                 (e)        Tax Opinions.....................................................  A-68
                 (f)        Required Consents................................................  A-68
                 (g)        Affiliate Agreements.............................................  A-68
Section     9.3  Further Conditions to Obligation of Interstate to Effect the Interstate
                 Merger......................................................................  A-68
                 (a)        Performance of Obligations.......................................  A-68
                 (b)        Representations and Warranties...................................  A-68
                 (c)        Closing Certificates.............................................  A-69
                 (d)        Material Adverse Effect..........................................  A-69
                 (e)        Tax Opinions.....................................................  A-69
                 (f)        Required Consents................................................  A-69
                 (g)        Affiliate Agreements.............................................  A-69
Section     9.4  Further Conditions to Obligation of WPL to Effect the Merger................  A-69
                 (a)        Performance of Obligations.......................................  A-69
</TABLE>
 
                                      A-7
<PAGE>
<TABLE>
<CAPTION>
                                                                                               PAGE
                                                                                               ----
<S>      <C>     <C>        <C>                                                                <C>
                 (b)        Representations and Warranties...................................  A-69
                 (c)        Closing Certificates.............................................  A-69
                 (d)        Material Adverse Effect..........................................  A-70
                 (e)        Tax Opinions.....................................................  A-70
                 (f)        Required Consents................................................  A-70
                 (g)        Affiliate Agreements.............................................  A-70
 
                                             ARTICLE X
                                 TERMINATION, AMENDMENT AND WAIVER
Section    10.1  Termination.................................................................  A-70
Section    10.2  Effect of Termination.......................................................  A-73
Section    10.3  Termination Fee; Expenses...................................................  A-73
                 (a)        Termination Fee Upon Breach or Withdrawal of Approval............  A-73
                 (b)        Additional Termination Fee.......................................  A-74
                 (c)        Second Termination Fee...........................................  A-75
                 (d)        Expenses.........................................................  A-75
                 (e)        Limitation on Termination Fees...................................  A-75
                 (f)        Certain Definitions..............................................  A-76
                            (i)  Participation Percentage....................................  A-76
                            (ii)  Target Party...............................................  A-76
Section    10.4  Amendment...................................................................  A-76
Section    10.5  Waiver......................................................................  A-76
 
                                            ARTICLE XI
                                        GENERAL PROVISIONS
Section    11.1  Nonsurvival; Effect of Representations and Warranties.......................  A-77
Section    11.2  Brokers.....................................................................  A-77
Section    11.3  Notices.....................................................................  A-77
Section    11.4  Miscellaneous...............................................................  A-79
Section    11.5  Interpretation..............................................................  A-79
Section    11.6  Counterparts; Effect........................................................  A-79
Section    11.7  Parties in Interest.........................................................  A-79
Section    11.8  Binding Effect; Benefits....................................................  A-80
Section    11.9  WAIVER OF JURY TRIAL AND CERTAIN DAMAGES....................................  A-80
Section    11.10 Enforcement.................................................................  A-80
</TABLE>
 
                                    EXHIBITS
 
<TABLE>
<S>        <C>        <C>        <C>
Exhibit    A             --      WPL/IES Stock Option Agreement
Exhibit    B             --      WPL/Interstate Stock Option Agreement
Exhibit    C             --      IES/WPL Stock Option Agreement
Exhibit    D             --      IES/Interstate Stock Option Agreement
Exhibit    E             --      Interstate/WPL Stock Option Agreement
Exhibit    F             --      Interstate/IES Stock Option Agreement
Exhibit    1.3           --      Plan of Merger
Exhibit    8.8(a)        --      Affilate Agreement of WPL
Exhibit    8.8(b)        --      Affiliate Agreement of IES and Interstate
Exhibit    8.15.1        --      WPL Employment Contract with Mr. Liu
Exhibit    8.15.2        --      WPL Employment Contract with Mr. Davis
Exhibit    8.15.3        --      WPL Employment Contract with Mr. Stoppelmoor
Exhibit    8.15.4        --      WPL Employment Contract with Mr. Chase
</TABLE>
 
                                      A-8
<PAGE>
                             INDEX OF DEFINED TERMS
 
<TABLE>
<CAPTION>
TERM                                                                                                                          PAGE
- ----------------------------------------------------------------------------------------------------------------------------  ----
<S>                                                                                                                           <C>
Acquisition.................................................................................................................  A-12
Acquisition Common Stock....................................................................................................  A-15
1935 Act....................................................................................................................  A-19
Affiliate...................................................................................................................  A-29
Affiliate Agreement.........................................................................................................  A-61
Affiliated Employees........................................................................................................  A-62
Agreement...................................................................................................................  A-12
Atomic Energy Act...........................................................................................................  A-22
Business Combination........................................................................................................  A-71
Business Combination Proposal...............................................................................................  A-64
Canceled Common Shares......................................................................................................  A-16
Certificates................................................................................................................  A-16
Class I.....................................................................................................................  A-64
Class II....................................................................................................................  A-64
Class III...................................................................................................................  A-64
Closing.....................................................................................................................  A-18
Closing Agreement...........................................................................................................  A-25
Closing Date................................................................................................................  A-18
Code........................................................................................................................  A-12
Company.....................................................................................................................  A-12
Confidentiality Agreement...................................................................................................  A-57
DAEC........................................................................................................................  A-40
DGCL........................................................................................................................  A-13
Disclosure Schedules........................................................................................................  A-61
Dissenting Shares...........................................................................................................  A-16
DOE.........................................................................................................................  A-22
Effective Time..............................................................................................................  A-14
Environmental Claim.........................................................................................................  A-28
Environmental Laws..........................................................................................................  A-28
Environmental Permits.......................................................................................................  A-27
ERISA.......................................................................................................................  A-25
Exchange Act................................................................................................................  A-22
Exchange Agent..............................................................................................................  A-16
FERC........................................................................................................................  A-22
Final Order.................................................................................................................  A-67
GAAP........................................................................................................................  A-12
Governmental Authority......................................................................................................  A-21
Hazardous Materials.........................................................................................................  A-28
HSR Act.....................................................................................................................  A-58
IBCA........................................................................................................................  A-13
Indemnified Liabilities.....................................................................................................  A-59
Indemnified Party...........................................................................................................  A-59
Indemnified Parties.........................................................................................................  A-59
IES.........................................................................................................................  A-12
IES Benefit Plans...........................................................................................................  A-36
IES Common Stock............................................................................................................  A-14
IES Disclosure Schedule.....................................................................................................  A-30
IES Directors...............................................................................................................  A-64
IES Dissenting Shares.......................................................................................................  A-16
IES Financial Statements....................................................................................................  A-34
IES/Interstate Stock Option Agreement.......................................................................................  A-12
</TABLE>
 
                                      A-9
<PAGE>
<TABLE>
<CAPTION>
TERM                                                                                                                          PAGE
- ----------------------------------------------------------------------------------------------------------------------------  ----
<S>                                                                                                                           <C>
IES Joint Venture...........................................................................................................  A-31
IES Material Adverse Effect.................................................................................................  A-31
IES Merger..................................................................................................................  A-12
IES Preferred Stock.........................................................................................................  A-31
IES Ratio...................................................................................................................  A-14
IES Required Consents.......................................................................................................  A-32
IES Required Statutory Approvals............................................................................................  A-33
IES Rights Agreement........................................................................................................  A-40
IES SEC Reports.............................................................................................................  A-33
IES Shareholders' Approval..................................................................................................  A-39
IES Special Meeting.........................................................................................................  A-58
IES Stock Awards............................................................................................................  A-63
IES Stock Option............................................................................................................  A-62
IES Subsidiary..............................................................................................................  A-31
IES/WPL Stock Option Agreement..............................................................................................  A-12
Initial Termination Date....................................................................................................  A-70
Interstate..................................................................................................................  A-12
Interstate Benefit Plans....................................................................................................  A-46
Interstate Common Stock.....................................................................................................  A-14
Interstate Directors........................................................................................................  A-64
Interstate Disclosure Schedule..............................................................................................  A-40
Interstate Dissenting Shares................................................................................................  A-16
Interstate Financial Statements.............................................................................................  A-43
Interstate/IES Stock Option Agreement.......................................................................................  A-12
Interstate Joint Venture....................................................................................................  A-41
Interstate Material Adverse Effect..........................................................................................  A-40
Interstate Merger...........................................................................................................  A-13
Interstate Preferred Stock..................................................................................................  A-15
Interstate Ratio............................................................................................................  A-15
Interstate Required Consents................................................................................................  A-42
Interstate Required Statutory Approval......................................................................................  A-42
Interstate SEC Reports......................................................................................................  A-43
Interstate Shareholders' Approval...........................................................................................  A-49
Interstate Special Meeting..................................................................................................  A-59
Interstate Subsidiary.......................................................................................................  A-41
Interstate/WPL Stock Option Agreement.......................................................................................  A-12
IRS.........................................................................................................................  A-25
Joint Proxy/Registration Statement..........................................................................................  A-57
Joint Venture...............................................................................................................  A-19
Kewaunee....................................................................................................................  A-30
knowledge...................................................................................................................  A-21
McLeod......................................................................................................................  A-14
McLeod Contengency..........................................................................................................  A-14
Merger......................................................................................................................  A-13
Merrill.....................................................................................................................  A-30
Morgan......................................................................................................................  A-39
New Interstate..............................................................................................................  A-12
New Interstate Common Stock.................................................................................................  A-15
New Interstate Preferred Stock..............................................................................................  A-15
New Utilities...............................................................................................................  A-13
New Utilities Common Stock..................................................................................................  A-15
Nonregulated Company........................................................................................................  A-66
Non-Target Party............................................................................................................  A-75
</TABLE>
 
                                      A-10
<PAGE>
<TABLE>
<CAPTION>
TERM                                                                                                                          PAGE
- ----------------------------------------------------------------------------------------------------------------------------  ----
<S>                                                                                                                           <C>
NRC.........................................................................................................................  A-22
NYSE........................................................................................................................  A-18
Payment Date................................................................................................................  A-51
Participation Percentage....................................................................................................  A-76
PBGC........................................................................................................................  A-25
Permits.....................................................................................................................  A-21
Plan of Merger..............................................................................................................  A-14
Power Act...................................................................................................................  A-22
Proxy Statement.............................................................................................................  A-23
Registration Statement......................................................................................................  A-23
Release.....................................................................................................................  A-29
Representatives.............................................................................................................  A-56
Salomon.....................................................................................................................  A-49
SEC.........................................................................................................................  A-12
Second Target Party.........................................................................................................  A-75
Securities Act..............................................................................................................  A-22
Stock Option Agreements.....................................................................................................  A-12
Stock Plans.................................................................................................................  A-63
Subsidiary..................................................................................................................  A-19
Target Party................................................................................................................  A-76
Tax Return..................................................................................................................  A-25
Tax Ruling..................................................................................................................  A-25
Taxes.......................................................................................................................  A-24
Three-Year Period...........................................................................................................  A-79
Transition Team.............................................................................................................  A-55
Utilities...................................................................................................................  A-31
Utilities Common Stock......................................................................................................  A-31
Utilities Preferred Stock...................................................................................................  A-31
Violation...................................................................................................................  A-20
WBCL........................................................................................................................  A-13
Wisconsin Regulatory Event..................................................................................................  A-13
WP&LC.......................................................................................................................  A-19
WP&LC Common Stock..........................................................................................................  A-19
WP&LC Preferred Stock.......................................................................................................  A-20
WPL.........................................................................................................................  A-12
WPL Benefit Plans...........................................................................................................  A-25
WPL Common Stock............................................................................................................  A-14
WPL Directors...............................................................................................................  A-64
WPL Disclosure Schedule.....................................................................................................  A-18
WPL Financial Statements....................................................................................................  A-22
WPL/IES Stock Option Agreement..............................................................................................  A-12
WPL/Interstate Stock Option Agreement.......................................................................................  A-12
WPL Joint Venture...........................................................................................................  A-19
WPL Material Adverse Effect.................................................................................................  A-18
WPL Rights..................................................................................................................  A-14
WPL Rights Agreement........................................................................................................  A-14
WPL Required Consents.......................................................................................................  A-21
WPL Required Statutory Approvals............................................................................................  A-21
WPL SEC Reports.............................................................................................................  A-22
WPL Shareholders' Approval..................................................................................................  A-29
WPL Special Meeting.........................................................................................................  A-58
WPL Subsidiary..............................................................................................................  A-19
WPS.........................................................................................................................  A-30
</TABLE>
 
                                      A-11
<PAGE>
    THIS AGREEMENT AND PLAN OF MERGER, dated as of November 10, 1995, as amended
(this  "AGREEMENT"),  by  and  among  WPL  Holdings,  Inc.,  a  holding  company
incorporated under the laws  of the State of  Wisconsin ("WPL"), IES  Industries
Inc.,  a  holding company  incorporated  under the  laws  of the  State  of Iowa
("IES"), Interstate  Power Company,  an  operating public  utility  incorporated
under  the laws of the State of Delaware ("INTERSTATE"), WPLH Acquisition Co., a
wholly-owned subsidiary  of WPL  incorporated under  the laws  of the  State  of
Wisconsin   ("ACQUISITION"),  and  Interstate   Power  Company,  a  wholly-owned
subsidiary of Interstate incorporated under the  laws of the State of  Wisconsin
("NEW INTERSTATE", and together with WPL, IES, Interstate and Acquisition, after
the Effective Time (as hereinafter defined), the "COMPANY"),
 
                              W I T N E S S E T H:
 
    WHEREAS,  WPL, IES and Interstate have determined  that it would be in their
respective best interests and in the interests of their respective  shareholders
to effect the transactions contemplated by this Agreement;
 
    WHEREAS,  in furtherance thereof, the respective Boards of Directors of WPL,
IES, Interstate, Acquisition and New Interstate have approved this Agreement and
the Merger (as defined  in Section 1.1  below) on the  terms and conditions  set
forth in this Agreement;
 
    WHEREAS,  the Board of  Directors of WPL  has approved and  WPL has executed
agreements with  IES  in  the form  of  Exhibit  A (the  "WPL/IES  STOCK  OPTION
AGREEMENT"),  and Interstate in the form of Exhibit B (the "WPL/INTERSTATE STOCK
OPTION AGREEMENT"),  the Board  of Directors  of IES  has approved  and IES  has
executed agreements with WPL in the form of Exhibit C (the "IES/WPL STOCK OPTION
AGREEMENT"),  and Interstate in the form of Exhibit D (the "IES/INTERSTATE STOCK
OPTION AGREEMENT"), and the  Board of Directors of  Interstate has approved  and
Interstate  has  executed agreements  with WPL  in  the form  of Exhibit  E (the
"INTERSTATE/WPL STOCK OPTION AGREEMENT") and IES  in the form of Exhibit F  (the
"INTERSTATE/IES  STOCK  OPTION  AGREEMENT")  (collectively,  the  "STOCK  OPTION
AGREEMENTS") whereby each of WPL, IES and Interstate, respectively, has  granted
to  the others an option to purchase shares of its common stock on the terms and
conditions provided in such agreements;
 
    WHEREAS,  for  Federal  income  tax  purposes,  it  is  intended  that   the
transactions  contemplated herein  will be reorganizations  described in SECTION
368(a) of the Internal Revenue  Code of 1986, as  amended (the "CODE"), and  the
regulations  thereunder,  and  that  the  parties  hereto  and  their respective
shareholders will recognize no gain or loss for Federal income tax purposes as a
result of the consummation of the Merger;
 
    WHEREAS, for accounting  purposes, it is  intended that the  Merger will  be
accounted  for as a  pooling of interests in  accordance with generally accepted
accounting principles  applied on  a consistent  basis ("GAAP")  and  applicable
regulations of the Securities and Exchange Commission (the "SEC");
 
    NOW,  THEREFORE, in consideration  of the premises  and the representations,
warranties, covenants  and  agreements  contained herein,  the  parties  hereto,
intending to be legally bound hereby, agree as follows:
 
                                   ARTICLE I
                                   THE MERGER
 
    Section  1.1  THE MERGER.   Upon the terms and  subject to the conditions of
this Agreement:
 
        (a) at the Effective Time the Merger shall be effected as follows:
 
           (i) IES  shall be  merged with  and into  WPL (the  "IES MERGER")  in
       accordance with the laws of the States of Wisconsin and Iowa;
 
                                      A-12
<PAGE>
           (ii)  Acquisition  shall  be  merged with  and  into  Interstate (the
       "INTERSTATE MERGER")  in  accordance  with  the laws  of  the  States  of
       Wisconsin and Delaware;
 
          (iii)  The  IES  Merger,  together  with  the  Interstate  Merger, are
       collectively referred to herein as the "MERGER;"
 
    PROVIDED, HOWEVER, that in the event that there has been a failure to obtain
    any WPL Required Statutory  Approvals due to  any limitations imposed  under
    Section  196.795 of the Wisconsin Statutes (a "WISCONSIN REGULATORY EVENT"),
    the Merger  shall be  effected  as follows,  with  the terms  "IES  Merger,"
    "Interstate Merger" and "Merger" being defined as set forth below:
 
           (i)   Interstate  shall  be  merged  with  and  into  New  Interstate
       (following such intermediate  merger, to be  deemed "Interstate" for  the
       purposes  of this  Agreement), with  New Interstate  to be  the surviving
       corporation; and
 
           (ii) Acquisition  shall  be merged  with  and into  Interstate,  with
       Interstate  to be  the surviving  corporation (steps  (i) and  (ii) being
       collectively referred to herein as the "INTERSTATE MERGER"); and
 
          (iii) Utilities (as hereinafter defined) shall be merged with and into
       a wholly-owned subsidiary  of IES  ("NEW UTILITIES,"  to be  formed as  a
       Wisconsin  corporation,  and following  such  intermediate merger,  to be
       deemed  "Utilities"  for  the  purposes  of  this  Agreement),  with  New
       Utilities to be the surviving corporation; and
 
          (iv)  IES shall  be merged  with and into  WPL (steps  (iii) and (iv),
       collectively, the "IES MERGER") in accordance with the laws of the States
       of Wisconsin and Iowa; and
 
           (v)  The  IES  Merger,  together  with  the  Interstate  Merger,  are
       collectively referred to herein as the "MERGER."
 
        (b)  WPL  shall be  the  surviving corporation  of  the IES  Merger, and
    Interstate shall be the surviving corporation of the Interstate Merger,  and
    each shall continue its respective corporate existence under the laws of the
    States of Wisconsin and Delaware, as applicable; and
 
        (c) the effects and the consequences of the Merger shall be as set forth
    in SECTION 1.2.
 
    Section 1.2  EFFECTS OF THE MERGER.  At the Effective Time,
 
        (a) the surviving corporation of the IES Merger shall change its name to
    Interstate Energy Corporation,
 
        (b)  the  Restated  Articles  of  Incorporation  of  WPL,  as  in effect
    immediately prior to  the Effective  Time, except  as set  forth in  SECTION
    1.2(a)  above, shall be the Restated Articles of Incorporation of WPL as the
    surviving corporation in the IES Merger until thereafter amended,
 
        (c) the By-laws of WPL, as in effect immediately prior to the  Effective
    Time,  shall be the By-laws  of WPL as the  surviving corporation in the IES
    Merger until thereafter amended,
 
        (d) the  Restated  Certificate of  Incorporation  of Interstate,  as  in
    effect  immediately  prior  to the  Effective  Time, shall  be  the Restated
    Certificate of Incorporation of Interstate  as the surviving corporation  in
    the Interstate Merger until thereafter amended, and
 
        (e)  the By-laws  of Interstate, as  in effect immediately  prior to the
    Effective Time,  shall  be  the  By-laws  of  Interstate  as  the  surviving
    corporation in the Interstate Merger until thereafter amended.
 
Subject  to the  foregoing, the  additional effects  of the  Merger shall  be as
provided in the applicable provisions of the Wisconsin Business Corporation  Law
(the  "WBCL"), the Iowa  Business Corporation Act (the  "IBCA") and the Delaware
General Corporation Law (the "DGCL").
 
                                      A-13
<PAGE>
    Section 1.3    EFFECTIVE TIME  OF  THE MERGER.    On the  Closing  Date  (as
hereinafter  defined), articles and certificates of merger together, in the case
of the IES  Merger, with a  Plan of  Merger in substantially  the form  attached
hereto  as Exhibit 1.3, which Plan of Merger is incorporated by reference herein
and deemed a part hereof (the "PLAN OF MERGER"), complying with the requirements
of the WBCL, the IBCA  and the DGCL, shall be  executed by WPL, IES,  Interstate
and  Acquisition (or, if a Wisconsin  Regulatory Event shall have occurred, WPL,
IES, Interstate, New Interstate, Utilities,  New Utilities and Acquisition)  and
shall  be  filed by  WPL,  Utilities and  Interstate,  as appropriate,  with the
Secretary of  State of  the State  of Wisconsin  pursuant to  the WBCL  and  the
Secretary of State of the State of Iowa pursuant to the IBCA, in the case of the
IES  Merger, and the Secretary of State of the State of Delaware pursuant to the
DGCL and the Secretary of State of the State of Wisconsin pursuant to the  WBCL,
in  the case of the Interstate Merger.  The Merger shall become effective on the
later of the times (the "EFFECTIVE TIME") specified in the appropriate  articles
and  certificates  of  merger filed  with  respect  to the  IES  Merger  and the
Interstate Merger, respectively.
 
                                   ARTICLE II
                              TREATMENT OF SHARES
 
    Section 2.1  EFFECT OF THE MERGER ON CAPITAL STOCK.  At the Effective  Time,
by  virtue of the Merger and without any action on the part of any holder of any
capital stock of WPL, IES, Interstate or Acquisition:
 
        (a)  CANCELLATION OF CERTAIN COMMON STOCK.
 
           (i) Each share of Common Stock, no par value, of IES (the "IES COMMON
       STOCK") that  is  owned  by  IES,  WPL or  Interstate  or  any  of  their
       respective  Subsidiaries (as  hereinafter defined) shall  be canceled and
       shall cease to exist, and
 
           (ii) each  share of  Common  Stock, par  value  $3.50 per  share,  of
       Interstate  (the "INTERSTATE COMMON STOCK") that  is owned by IES, WPL or
       Interstate or any of their respective Subsidiaries shall be canceled  and
       shall cease to exist.
 
        (b)  CONVERSION OF CERTAIN COMMON STOCK.
 
           (i) Each issued and outstanding share of IES Common Stock (other than
       shares  canceled pursuant to SECTION  2.1(a)(i) and IES Dissenting Shares
       (as hereinafter defined)) shall  be converted into  the right to  receive
       0.98  duly  authorized,  validly  issued,  fully  paid  and nonassessable
       (except as  otherwise provided  in SECTION  180.0622(2)(b) of  the  WBCL)
       shares  of Common Stock,  par value $.01  per share, of  WPL ("WPL COMMON
       STOCK"), including, if applicable,  associated rights (the "WPL  RIGHTS")
       to  purchase shares  of WPL  Common Stock pursuant  to the  terms of that
       certain Rights  Agreement between  WPL  and Morgan  Shareholder  Services
       Trust  Company, as Rights Agent thereunder, dated as of February 22, 1989
       (the "WPL RIGHTS AGREEMENT"). Until the Distribution Date (as defined  in
       the  WPL Rights  Agreement) all references  in this Agreement  to the WPL
       Common Stock  shall  be deemed  to  include the  associated  WPL  Rights.
       Notwithstanding  the foregoing, if the McLeod Contingency (as hereinafter
       defined) shall have occurred prior to  the Closing Date, each issued  and
       outstanding  share  of  IES  Common  Stock  (other  than  shares canceled
       pursuant to  SECTION  2.1(a)(i)  and  IES  Dissenting  Shares)  shall  be
       converted into the right to receive 1.01 duly authorized, validly issued,
       fully  paid and  nonassessable (except  as otherwise  provided in SECTION
       180.0622(2)(b) of  the WBCL)  shares of  WPL Common  Stock. The  specific
       exchange  ratio  at  which  shares of  IES  Common  Stock  are ultimately
       converted into shares of WPL Common Stock in the IES Merger is  hereafter
       referred  to as  the "IES  RATIO". As  used in  this Agreement,  the term
       "MCLEOD CONTINGENCY"  shall  mean the  completion  of a  firm  commitment
       underwritten  intitial public offering of Class A common stock by McLeod,
       Inc., a Delaware corporation ("MCLEOD"), at a per share price equal to or
       greater than $13.00 (as adjusted for any stock split, recapitalization or
       the like effected prior to the completion of
 
                                      A-14
<PAGE>
       such  offering,  other  than  the  stock  split  disclosed  in   McLeod's
       registration statement on Form S-1 filed with the Securities and Exchange
       Commission  on April 2, 1996), that results in McLeod (a) receiving gross
       proceeds of  such  offering equal  to  or  greater than  $75  million  in
       addition  to any gross proceeds from the sale of its Class A common stock
       to exisiting  stockholders  and (b)  having  its Class  A  common  stock,
       immediately  following the  completion of  such initial  public offering,
       registered pursuant to  Section 12  of the Exchange  Act (as  hereinafter
       defined).
 
           (ii)  Each issued  and outstanding  share of  Interstate Common Stock
       (other than  shares canceled  pursuant to  SECTION 2.1(a)(ii))  shall  be
       converted  into the right  to receive 1.11  (the "INTERSTATE RATIO") duly
       authorized, validly  issued,  fully  paid and  nonassessable  (except  as
       otherwise  provided in SECTION 180.0622(2)(b) of  the WBCL) shares of WPL
       Common Stock, PROVIDED,  HOWEVER, that  if a  Wisconsin Regulatory  Event
       shall  have  occurred, each  issued and  outstanding share  of Interstate
       Common Stock (other than shares canceled pursuant to SECTION  2.1(a)(ii))
       shall  FIRST automatically be converted into one duly authorized, validly
       issued, fully paid  and nonassessable  (except as  otherwise provided  in
       SECTION  180.0622(2)(b) of  the WBCL)  share of  Common Stock,  par value
       $3.50 per share, of  New Interstate (the  "NEW INTERSTATE COMMON  STOCK")
       and  THEREAFTER, such one  share of New Interstate  Common Stock shall be
       converted into the right to receive a number of duly authorized,  validly
       issued,  fully paid  and nonassessable  (except as  otherwise provided in
       SECTION 180.0622(2)(b) of the WBCL) shares  of WPL Common Stock equal  to
       the Interstate Ratio.
 
          (iii) If a Wisconsin Regulatory Event shall have occurred, each issued
       and  outstanding share of Utilities Common Stock (as hereinafter defined)
       shall be converted into the right to receive one duly authorized, validly
       issued, fully paid  and nonassessable  (except as  otherwise provided  in
       SECTION  180.0622(2)(b) of  the WBCL)  share of  Common Stock,  par value
       $2.50 per share, of New Utilities (the "NEW UTILITIES COMMON STOCK").
 
          (iv) Upon such conversions and except as otherwise provided in SECTION
       2.2, all such shares of IES  Common Stock, Interstate Common Stock  (and,
       if  a Wisconsin  Regulatory Event  shall have  occurred, Utilities Common
       Stock) shall  be  canceled and  cease  to exist,  and  each holder  of  a
       certificate formerly representing any such shares of IES Common Stock and
       Interstate  Common  Stock (and,  if  applicable, Utilities  Common Stock)
       shall cease to  have rights  with respect  thereto, except  the right  to
       receive the shares of WPL Common Stock (or New Utilities Common Stock) to
       be  issued in consideration therefor upon (in  the case of the IES Common
       Stock and the Interstate Common Stock) the surrender of such  certificate
       in  accordance with SECTION 2.3 and any cash in lieu of fractional shares
       of WPL Common Stock.
 
        (c)  INTERSTATE PREFERRED STOCK.   Each issued and outstanding share  of
    Preferred  Stock, $50  par value,  of Interstate  (the "INTERSTATE PREFERRED
    STOCK") shall be unchanged  as a result of  the Interstate Merger and  shall
    remain  outstanding  thereafter,  PROVIDED,  HOWEVER,  that  if  a Wisconsin
    Regulatory Event shall have occurred,  each outstanding share of  Interstate
    Preferred  Stock (other than shares owned directly or indirectly by WPL, IES
    or Interstate and other than Interstate Dissenting Shares) will be converted
    into one share  of Preferred Stock,  $50 par value,  of New Interstate  (the
    "NEW INTERSTATE PREFERRED STOCK") with terms (including dividend rights) and
    designations  under the  New Interstate  restated articles  of incorporation
    substantially identical  to  those of  the  converted shares  of  Interstate
    Preferred  Stock under the Interstate restated certificate of incorporation.
    In the event that a Wisconsin Regulatory Event shall have occurred, from and
    after  the  Effective   Time,  each   outstanding  certificate   theretofore
    representing  shares of Interstate  Preferred Stock shall  be deemed for all
    purposes to evidence the  ownership of and to  represent an equal number  of
    shares  of  New  Interstate  Preferred  Stock  into  which  such  shares  of
    Interstate Preferred Stock shall have been converted.
 
        (d)   CONVERSION OF  ACQUISITION COMMON  STOCK.   All of  the shares  of
    Common  Stock, par value  $0.01 per share,  of Acquisition (the "ACQUISITION
    COMMON STOCK") issued and outstanding
 
                                      A-15
<PAGE>
    immediately  prior to the Effective Time shall be converted into that number
    of shares of Interstate  Common Stock (as the  surviving corporation in  the
    Interstate  Merger) which  shall be  equivalent to  the aggregate  number of
    shares of Interstate Common Stock (exclusive of the shares canceled pursuant
    to SECTION  2.1(a)(ii))  issued and  outstanding  immediately prior  to  the
    Effective  Time, PROVIDED,  HOWEVER, if  a Wisconsin  Regulatory Event shall
    have occurred, all  of the  shares of  Acquisition Common  Stock issued  and
    outstanding  immediately prior to the Effective Time shall be converted into
    that number  of shares  of New  Interstate Common  Stock (as  the  surviving
    corporation  in  the Interstate  Merger) which  shall  be equivalent  to the
    aggregate number of shares of New Interstate Common Stock (exclusive of  the
    shares  canceled  pursuant  to SECTION  2.1(a)(ii))  issued  and outstanding
    immediately prior to the Effective Time. From and after the Effective  Time,
    each  outstanding certificate theretofore representing shares of Acquisition
    Common Stock shall be deemed for  all purposes to evidence ownership of  and
    to  represent  the  number  of  shares of  Interstate  Common  Stock  or New
    Interstate  Common  Stock,  as  appropriate,  into  which  such  shares   of
    Acquisition Common Stock shall have been converted.
 
        (e)  REDEMPTION OF UTILITIES PREFERRED STOCK.  If a Wisconsin Regulatory
    Event  shall have occurred,  all of the shares  of Utilities Preferred Stock
    (as hereinafter defined)  issued and  outstanding immediately  prior to  the
    Effective Time shall be redeemed prior to consummation of the Merger.
 
    Section 2.2  DISSENTING SHARES.
 
        (a)  Shares of IES Common Stock held by any holder entitled to relief as
    a dissenting  shareholder  under SECTION  490.1302  of the  IBCA  (the  "IES
    DISSENTING  SHARES") shall  not be converted  into the right  to receive WPL
    Common Stock in  the IES Merger,  but shall be  canceled and converted  into
    such consideration as may be due with respect to such shares pursuant to the
    applicable  provisions of  SECTIONS 490.1320  through 490.1330  of the IBCA,
    unless and until the  right of such  holder to receive  fair cash value  for
    such  Dissenting Shares  (as hereinafter  defined) terminates  in accordance
    with SECTIONS  490.1320 through  490.1330  of the  IBCA.  If such  right  is
    terminated  otherwise than by the purchase of  such shares by WPL, then such
    shares shall cease to be Dissenting Shares and shall represent the right  to
    receive WPL Common Stock, as provided in SECTION 2.1(b)(i).
 
        (b)  Shares of Interstate Preferred Stock held by any holder entitled to
    relief as  a dissenting  shareholder  under SECTION  262  of the  DGCL  (the
    "INTERSTATE  DISSENTING SHARES,"  and, collectively with  the IES Dissenting
    Shares, the "DISSENTING SHARES") shall  be canceled and converted into  such
    consideration  as may  be due  with respect to  such shares  pursuant to the
    applicable provisions  of  SECTION  262  of  the  DGCL.  If  such  right  is
    terminated  otherwise than by the purchase of  such shares by WPL, then such
    shares shall cease to be Dissenting Shares and shall remain outstanding.
 
    Section 2.3  ISSUANCE OF NEW CERTIFICATES.
 
        (a)  DEPOSIT  WITH EXCHANGE  AGENT.  As  soon as  practicable after  the
    Effective  Time, WPL  shall deposit with  such bank, trust  company or other
    appropriate entity  mutually  agreeable  to WPL,  IES  and  Interstate  (the
    "EXCHANGE  AGENT"),  certificates representing  shares  of WPL  Common Stock
    required to effect the issuances referred  to in SECTION 2.1, together  with
    cash payable in respect of fractional shares pursuant to SECTION 2.3(d).
 
        (b)  ISSUANCE PROCEDURES.
 
           (i)  As soon  as practicable after  the Effective  Time, the Exchange
       Agent  shall  mail  to  each  holder  of  record  of  a  certificate   or
       certificates   (the  "CERTIFICATES")  which   immediately  prior  to  the
       Effective Time  represented outstanding  shares of  IES Common  Stock  or
       Interstate  Common Stock, as the case may be (collectively, the "CANCELED
       COMMON SHARES"),  that were  canceled  and became  instead the  right  to
       receive  shares of  WPL Common Stock  pursuant to SECTION  2.1(b) and the
       Plan of  Merger,  (A)  a  letter  of  transmittal  (which  shall  specify
 
                                      A-16
<PAGE>
       that  delivery  shall be  effected, and  risk  of loss  and title  to the
       Certificates shall pass, only upon actual delivery of the Certificates to
       the Exchange  Agent),  and (B)  instructions  for use  in  effecting  the
       surrender  of the Certificates in  exchange for certificates representing
       WPL Common Stock.
 
           (ii) Upon  surrender  of a  Certificate  to the  Exchange  Agent  for
       cancellation  (or to such  other agent or  agents as may  be appointed by
       agreement of  WPL, IES  and Interstate),  together with  a duly  executed
       letter  of transmittal  and such  other documents  as the  Exchange Agent
       shall require,  the  holder of  such  Certificate shall  be  entitled  to
       receive  a certificate  representing that number  of whole  shares of WPL
       Common Stock which such holder has  the right to receive pursuant to  the
       provisions  of this Article II and the Plan  of Merger. In the event of a
       transfer of ownership of Canceled  Common Shares which is not  registered
       in  the transfer  records of  IES or  Interstate, as  the case  may be, a
       certificate representing the proper number of shares of WPL Common  Stock
       may  be  issued  to a  transferee  if the  Certificate  representing such
       Canceled Common Shares is presented to the Exchange Agent, accompanied by
       all documents  required  to evidence  and  effect such  transfer  and  by
       evidence  satisfactory to  the Exchange  Agent that  any applicable stock
       transfer taxes have been paid.
 
          (iii) Until  surrendered as  contemplated by  this SECTION  2.3,  each
       Certificate  shall  be deemed  at any  time after  the Effective  Time to
       represent only the right to  receive upon such surrender the  certificate
       representing  WPL Common Stock and cash  in lieu of any fractional shares
       of WPL Common Stock contemplated by this SECTION 2.3.
 
        (c)  DISTRIBUTIONS WITH RESPECT TO UNSURRENDERED SHARES.
 
           (i) No dividends or  other distributions declared  or made after  the
       Effective  Time with respect to shares of  WPL Common Stock with a record
       date after  the  Effective  Time shall  be  paid  to the  holder  of  any
       unsurrendered  Certificate with respect to the shares of WPL Common Stock
       represented thereby  and no  cash payment  in lieu  of fractional  shares
       shall  be paid to  any such holder  pursuant to SECTION  2.3(d) until the
       holder of record  of such Certificate  (or a transferee  as described  in
       SECTION 2.3(b)) shall surrender such Certificate.
 
           (ii)  Subject to the effect of  unclaimed property, escheat and other
       applicable laws, following surrender of any such Certificate, there shall
       be paid to the  record holders (or a  transferee as described in  SECTION
       2.3(b)) of the certificates representing whole shares of WPL Common Stock
       issued in consideration therefor, without interest,
 
               (A)  at the time of such surrender, the amount of cash in lieu of
           a fractional  share of  WPL Common  Stock to  which such  holder  (or
           transferee)  is entitled pursuant to SECTION 2.3(d) and the amount of
           dividends or  other  distributions  with  a  record  date  after  the
           Effective  Time which theretofore  became payable but  which were not
           paid by reason of SECTION 2.3(c)(i) with respect to such whole shares
           of WPL Common Stock, and
 
               (B) at the appropriate payment  date, the amount of dividends  or
           other  distributions with a record date  after the Effective Time but
           prior to surrender and a payment date subsequent to surrender payable
           with respect to such whole shares of WPL Common Stock.
 
        (d)  NO FRACTIONAL SECURITIES.
 
           (i)  Notwithstanding  any  other  provision  of  this  Agreement,  no
       certificates  or scrip representing fractional shares of WPL Common Stock
       shall be issued upon the surrender for exchange of Certificates and  such
       fractional  shares shall not entitle the owner  thereof to vote as, or to
       any other rights of, a holder of WPL Common Stock.
 
           (ii) A holder  of IES  Common Stock  or Interstate  Common Stock  who
       would  otherwise have been entitled to  receive a fractional share of WPL
       Common Stock shall be entitled to
 
                                      A-17
<PAGE>
       receive a cash  payment in  lieu of such  fractional share  in an  amount
       equal  to  the product  (rounded to  the nearest  cent) of  such fraction
       (rounded to the nearest thousandth) multiplied by the average of the last
       reported sales price, regular way, per share of WPL Common Stock, on  the
       New York Stock Exchange ("NYSE") Composite Tape for the ten business days
       prior  to and including the last business day prior to the Effective Time
       on which WPL Common  Stock was traded on  the NYSE, without any  interest
       thereon.
 
        (e)    CLOSING OF  COMMON  STOCK TRANSFER  BOOKS.   From  and  after the
    Effective Time, the stock transfer books of IES and Interstate with  respect
    to  shares  of  IES Common  Stock  and  Interstate Common  Stock  issued and
    outstanding prior to the Effective Time  shall be closed and no transfer  of
    any  such shares  shall thereafter  be made.  If, after  the Effective Time,
    Certificates are presented to WPL or Interstate, they shall be canceled  and
    exchanged  for certificates representing the appropriate number of shares of
    WPL Common Stock as provided in this SECTION 2.3.
 
        (f)  TERMINATION OF EXCHANGE  AGENT.  Any certificates representing  WPL
    Common  Stock deposited with  the Exchange Agent  pursuant to SECTION 2.3(a)
    and not exchanged within one year after the Effective Time pursuant to  this
    SECTION  2.3 shall be returned  by the Exchange Agent  to the Company, which
    shall thereafter act as Exchange Agent. All funds held by the Exchange Agent
    for payment to the  holders of unsurrendered  Certificates and unclaimed  at
    the  end  of one  year  from the  Effective Time  shall  be returned  to the
    Company, after which  time any  holder of  unsurrendered Certificates  shall
    look  as a general creditor only to the Company for payment of such funds to
    which such holder may be due,  subject to applicable law. The Company  shall
    not  be liable to any person for such  shares or funds delivered to a public
    official pursuant to any applicable  abandoned property, escheat or  similar
    law.
 
                                  ARTICLE III
                                  THE CLOSING
 
    Section  3.1  THE CLOSING.  The  closing of the Merger (the "CLOSING") shall
take place  at  the offices  of  Foley &  Lardner,  777 East  Wisconsin  Avenue,
Milwaukee,  Wisconsin, at  10:00 a.m. (Milwaukee,  Wisconsin local  time) on the
second business day  immediately following  the date on  which the  last of  the
conditions  set forth in  Article IX hereof  is fulfilled or  waived, or at such
other time and date and  place as WPL, IES  and Interstate shall mutually  agree
(the "CLOSING DATE").
 
                                   ARTICLE IV
                     REPRESENTATIONS AND WARRANTIES OF WPL
 
    WPL represents and warrants to IES and Interstate as follows:
 
    Section 4.1  ORGANIZATION AND QUALIFICATION.  Except as set forth in SECTION
4.1  of the Disclosure Schedule to this  Agreement prepared and delivered by WPL
(the "WPL  DISCLOSURE SCHEDULE"),  each  of WPL  and  the WPL  Subsidiaries  (as
hereinafter  defined) is a  corporation duly organized,  validly existing and in
good standing  (to the  extent  applicable) under  the  laws of  its  respective
jurisdiction of incorporation or organization, has all requisite corporate power
and  authority,  and has  been duly  authorized by  all necessary  approvals and
orders to own, lease and operate its assets and properties to the extent  owned,
leased  and operated and to  carry on its business as  it is now being conducted
and is duly  qualified and in  good standing  (to the extent  applicable) to  do
business  in each respective jurisdiction in which the nature of its business or
the ownership or leasing of its  assets and properties makes such  qualification
necessary, other than in such jurisdictions where the failure to be so qualified
and  in  good  standing would  not,  when  taken together  with  all  other such
failures,  have  a  material  adverse   effect  on  the  business,   operations,
properties,  assets,  condition  (financial  or otherwise),  or  the  results of
operations of  WPL  and  the  WPL  Subsidiaries taken  as  a  whole  or  on  the
consummation  of the transactions  contemplated hereby (a  "WPL MATERIAL ADVERSE
EFFECT").
 
                                      A-18
<PAGE>
    Section 4.2  SUBSIDIARIES.
 
        (a) SECTION 4.2 of the WPL Disclosure Schedule sets forth a  description
    as  of the  date hereof,  of all  WPL Subsidiaries  and WPL  Joint Ventures,
    including (i) the name of each  such entity and WPL's interest therein,  and
    (ii)  a  brief  description  of  the principal  line  or  lines  of business
    conducted by each such entity.
 
        (b) Except as set forth in  SECTION 4.2 of the WPL Disclosure  Schedule,
    none  of the  WPL Subsidiaries  or WPL Joint  Ventures is  a "PUBLIC UTILITY
    COMPANY," a "HOLDING COMPANY," a  "SUBSIDIARY COMPANY" or an "AFFILIATE"  of
    any  public utility company within the  meaning of SECTION 2(a)(5), 2(a)(7),
    2(a)(8) or 2(a)(11) of  the Public Utility Holding  Company Act of 1935,  as
    amended (the "1935 ACT"), respectively.
 
        (c)  Except as set forth in SECTION  4.2 of the WPL Disclosure Schedule,
    all of  the issued  and outstanding  shares  of capital  stock of  each  WPL
    Subsidiary  are duly  authorized, validly issued,  fully paid, nonassessable
    (except as otherwise  provided in  SECTION 180.0622(2)(b) of  the WBCL)  and
    free  of preemptive  rights, and are  owned, directly or  indirectly, by WPL
    free and  clear  of any  liens,  claims, encumbrances,  security  interests,
    equities,  charges and  options of any  nature whatsoever, and  there are no
    outstanding subscriptions, options, calls, contracts, voting trusts, proxies
    or other commitments, understandings, restrictions, arrangements, rights  or
    warrants,   including  any  right  of   conversion  or  exchange  under  any
    outstanding security, instrument or other agreement, obligating any such WPL
    Subsidiary to issue, deliver  or sell, or cause  to be issued, delivered  or
    sold,  additional shares  of its  capital stock,  or granting  to any person
    other than WPL or a WPL Subsidiary any right to participate in its dividends
    or earnings  or  obligating it  to  grant, extend  or  enter into  any  such
    agreement or commitment.
 
        (d) As used in this Agreement,
 
           (i)  "SUBSIDIARY" of  a person  shall mean  any corporation  or other
       entity (including partnerships and other business associations) of  which
       at  least a  majority of  the outstanding  capital stock  or other voting
       securities having  voting power  under  ordinary circumstances  to  elect
       directors or similar members of the governing body of such corporation or
       entity  shall at the time be held, directly or indirectly, by such person
       or entity;
 
           (ii) "WPL SUBSIDIARY" shall mean any Subsidiary of WPL;
 
          (iii) "JOINT VENTURE" of a person or entity shall mean any corporation
       or other entity (including partnerships and other business  associations)
       that  is not a Subsidiary of such  person or entity, in which such person
       or one or more of its Subsidiaries owns directly or indirectly an  equity
       interest,  other  than  equity  interests  held  for  passive  investment
       purposes which are less than 5%  of each class of the outstanding  voting
       securities or equity interests of any such entity; and
 
          (iv)  "WPL JOINT VENTURE" shall  mean any Joint Venture  of WPL or any
       WPL Subsidiary.
 
    Section 4.3  CAPITALIZATION.
 
        (a) The authorized capital stock  of WPL consists of 100,000,000  shares
    of  WPL Common Stock of which  30,773,588 shares were issued and outstanding
    as of September 30, 1995;
 
        (b) The authorized capital  stock of Wisconsin  Power and Light  Company
    ("WP&LC"), a Wisconsin corporation and a Subsidiary of WPL, consists of
 
           (A)  18,000,000  shares  of  Common Stock,  $5  par  value,  of which
       13,236,601 shares were issued  and outstanding as  of September 30,  1995
       (the "WP&LC COMMON STOCK"), and
 
                                      A-19
<PAGE>
           (B) 3,750,000 shares of Preferred Stock without mandatory redemption,
       (4.50%  series, 4.80% series,  4.96% series, 4.40%  series, 4.76% series,
       6.50% series  and  6.20%  series)  of which  1,049,225  were  issued  and
       outstanding  as  of September  30, 1995  (the classes  set forth  in this
       clause (B)  being  referred  to collectively  as,  the  "WP&LC  PREFERRED
       STOCK").
 
        (c)  All of the issued and outstanding shares of WPL Common Stock, WP&LC
    Common Stock and  WP&LC Preferred Stock  are, and any  shares of WPL  Common
    Stock issued pursuant to the Merger and the WPL/Interstate and WPL/IES Stock
    Option  Agreements  will be  duly  authorized, validly  issued,  fully paid,
    nonassessable (except as otherwise provided in SECTION 180.0622(2)(b) of the
    WBCL) and free of preemptive rights.
 
        (d) Except as set forth in  SECTION 4.3 of the WPL Disclosure  Schedule,
    as  of the  date hereof,  there are  no outstanding  subscriptions, options,
    calls,   contracts,   voting   trusts,   proxies   or   other   commitments,
    understandings,  restrictions, arrangements,  rights or  warrants, including
    any  right  of  conversion  or  exchange  under  any  outstanding  security,
    instrument or other agreement, obligating WPL or any of the WPL Subsidiaries
    to  issue,  deliver or  sell,  or cause  to  be issued,  delivered  or sold,
    additional shares of the capital stock  of WPL, or obligating WPL to  grant,
    extend  or enter into any such agreement or commitment, other than under the
    WPL/IES and WPL/Interstate Stock Option Agreements.
 
    Section 4.4  AUTHORITY; NON-CONTRAVENTION; STATUTORY APPROVALS; COMPLIANCE.
 
        (a)  AUTHORITY.  WPL has all requisite corporate power and authority  to
    enter  into this Agreement  and the WPL/IES  and WPL/Interstate Stock Option
    Agreements, and, subject  to the applicable  WPL Shareholders' Approval  (as
    hereinafter defined) and the applicable WPL Required Statutory Approvals (as
    hereinafter  defined), to consummate the transactions contemplated hereby or
    thereby. The execution and  delivery of this Agreement  and the WPL/IES  and
    WPL/Interstate  Stock Option Agreements  and the consummation  by WPL of the
    transactions contemplated hereby  and thereby have  been duly authorized  by
    all  necessary corporate action on the part of WPL, subject to obtaining the
    applicable WPL  Shareholders'  Approval.  Each of  this  Agreement  and  the
    WPL/IES and WPL/Interstate Stock Option Agreements has been duly and validly
    executed and delivered by WPL and, assuming the due authorization, execution
    and delivery hereof and thereof by the other signatories hereto and thereto,
    constitutes  the valid and binding obligation  of WPL enforceable against it
    in accordance  with  its terms,  except  as  may be  limited  by  applicable
    bankruptcy,  insolvency, reorganization or other  similar laws affecting the
    enforcement of creditors' rights generally, and except that the availability
    of equitable remedies, including specific performance, may be subject to the
    discretion of any court before which any proceeding therefor may be brought.
 
        (b)  NON-CONTRAVENTION.   Except as set forth  in Section 4.4(b) of  the
    WPL  Disclosure Schedule, the  execution and delivery  of this Agreement and
    the WPL/IES and the  WPL/Interstate Stock Option Agreements  by WPL do  not,
    and the consummation of the transactions contemplated hereby or thereby will
    not  violate, conflict with, or  result in a breach  of any provision of, or
    constitute a  default (with  or without  notice or  lapse of  time or  both)
    under,  or result in  the termination or modification  of, or accelerate the
    performance required by, or result in a right of termination,  cancellation,
    or  acceleration of any obligation or the loss of a benefit under, or result
    in the creation of any lien,  security interest, charge or encumbrance  upon
    any of the properties or assets of WPL or any of the WPL Subsidiaries or WPL
    Joint  Ventures (any such violation, conflict, breach, default, termination,
    modification, cancellation, acceleration,  loss or  creation, a  "VIOLATION"
    with  respect to  WPL, such  term when used  in Articles  V and  VI having a
    correlative meaning  with  respect  to  IES  and  Interstate,  respectively)
    pursuant to any provisions of:
 
           (i)  the  Articles  of Incorporation,  By-laws  or  similar governing
       documents of WPL or any of the WPL Subsidiaries or WPL Joint Ventures;
 
                                      A-20
<PAGE>
           (ii) subject to  obtaining the WPL  Required Statutory Approvals  and
       the  receipt  of  the  WPL  Shareholders'  Approval,  any  statute,  law,
       ordinance, rule, regulation, judgment,  decree, order, injunction,  writ,
       permit  or license of any Governmental Authority (as hereinafter defined)
       applicable to WPL or any of the WPL Subsidiaries or WPL Joint Ventures or
       any of their respective properties or assets; or
 
          (iii) subject  to  obtaining the  third-party  consents set  forth  in
       SECTION  4.4(b)  of  the  WPL  Disclosure  Schedule  (the  "WPL  REQUIRED
       CONSENTS") any note, bond, mortgage,  indenture, deed of trust,  license,
       franchise,  permit,  concession,  contract,  lease  or  other instrument,
       obligation or  agreement of  any kind  to which  WPL or  any of  the  WPL
       Subsidiaries  or WPL Joint Ventures  is a party or by  which it or any of
       its properties or assets may be bound or affected,
 
    excluding from the foregoing clauses  (ii) and (iii) such violations  which,
    in  the aggregate do not,  and insofar as reasonably  can be foreseen, would
    not, have a WPL Material Adverse Effect.
 
        (c)  STATUTORY APPROVALS.  No declaration, filing or registration  with,
    or  notice to or authorization, consent  or approval of, any court, Federal,
    state, local or foreign governmental  or regulatory body (including a  stock
    exchange  or other self-regulatory body) or authority (each, a "GOVERNMENTAL
    AUTHORITY") is necessary for the execution and delivery of this Agreement or
    the WPL/IES  and  WPL/Interstate  Stock  Option Agreements  by  WPL  or  the
    consummation  by  WPL of  the transactions  contemplated hereby  or thereby,
    except as described in  SECTION 4.4(c) of the  WPL Disclosure Schedule  (the
    "WPL  REQUIRED STATUTORY APPROVALS," it  being understood that references in
    this Agreement to  "OBTAINING" such WPL  Required Statutory Approvals  shall
    mean  making  such  declarations,  filings  or  registrations;  giving  such
    notices; obtaining such  authorizations, consents or  approvals; and  having
    such waiting periods expire as are necessary to avoid a violation of law).
 
        (d)  COMPLIANCE.
 
           (i)  (A)   Except as  set forth  in SECTION  4.4(d), SECTION  4.10 or
       SECTION 4.11 of the WPL Disclosure  Schedule, or as disclosed in the  WPL
       SEC  Reports (as  hereinafter defined)  filed prior  to the  date hereof,
       neither WPL nor any of the WPL Subsidiaries nor, to the knowledge of WPL,
       any WPL Joint Venture,  is in violation of,  is under investigation  with
       respect  to any violation  of, or has  been given notice  or been charged
       with any  violation  of,  any  law,  statute,  order,  rule,  regulation,
       ordinance  or  judgment  (including, without  limitation,  any applicable
       environmental  law,  ordinance   or  regulation)   of  any   Governmental
       Authority,  except for  violations which,  in the  aggregate do  not, and
       insofar as reasonably  can be foreseen,  would not, have  a WPL  Material
       Adverse Effect.
 
               (B)  For purposes of this  Agreement "KNOWLEDGE" shall mean, with
           respect to any party hereto,  the actual knowledge after due  inquiry
           of   principal  executive   officers  of  WPL,   IES  or  Interstate,
           respectively set forth in SECTIONS  4.4(d), 5.4(d) and 6.4(d) of  the
           WPL  Disclosure  Schedule,  IES Disclosure  Schedule  (as hereinafter
           defined) and Interstate Disclosure Schedule (as hereinafter defined).
 
           (ii) Except as set forth in SECTION 4.4(d) or in SECTION 4.11 of  the
       WPL  Disclosure Schedule, WPL and the  WPL Subsidiaries and the WPL Joint
       Ventures have all  permits, licenses, franchises  and other  governmental
       authorizations,  consents  and  approvals  (collectively,  the "PERMITS")
       necessary to  conduct their  businesses  as presently  conducted,  except
       those  the  failure of  which to  obtain,  in the  aggregate do  not, and
       insofar as reasonably  can be foreseen,  would not, have  a WPL  Material
       Adverse Effect.
 
                                      A-21
<PAGE>
          (iii)  Except as  set forth  in SECTION  4.4(d) of  the WPL Disclosure
       Schedule, each of WPL and the WPL Subsidiaries and WPL Joint Ventures  is
       not  in breach, violation or default  in the performance or observance of
       any term or provision of, and no event has occurred which, with lapse  of
       time or action by a third party, could result in a default under,
 
               (A) its Articles of Incorporation or By-laws, or
 
               (B)  any  contract, commitment,  agreement,  indenture, mortgage,
           loan  agreement,  note,  lease,  bond,  license,  approval  or  other
           instrument to which it is a party or by which it is bound or to which
           any  of its property  is subject, except  for breaches, violations or
           defaults which, in the  aggregate do not,  and insofar as  reasonably
           can be foreseen, would not, have a WPL Material Adverse Effect.
 
    Section 4.5  REPORTS AND FINANCIAL STATEMENTS.
 
        (a)  The filings  required to  be made by  WPL and  the WPL Subsidiaries
    since January 1,  1992 under  the Securities Act  of 1933,  as amended  (the
    "SECURITIES  ACT"), the  Securities Exchange  Act of  1934, as  amended (the
    "EXCHANGE ACT"), the 1935 Act, the Federal Power Act (the "POWER ACT"),  the
    Atomic  Energy  Act  of  1954,  as amended  (the  "ATOMIC  ENERGY  ACT") and
    applicable state laws  and regulations  have been  filed with  the SEC,  the
    Federal  Energy Regulatory  Commission (the "FERC"),  the Nuclear Regulatory
    Commission (the  "NRC"),  the  Department  of  Energy  (the  "DOE")  or  any
    appropriate state public utilities commission, as the case may be, including
    all  forms,  statements,  reports,  agreements  (oral  or  written)  and all
    documents, exhibits, amendments  and supplements  appertaining thereto,  and
    complied,  as of their  respective dates, in all  material respects with all
    applicable requirements  of  the  appropriate  statute  and  the  rules  and
    regulations thereunder.
 
        (b)  WPL has made  available to IES  and Interstate a  true and complete
    copy of each form, report,  schedule, registration statement and  definitive
    proxy statement filed by each of WPL and WP&LC with the SEC since January 1,
    1992  (as such documents have since the time of their filing been amended or
    supplemented, the  "WPL SEC  REPORTS") and  each other  filing described  in
    SECTION  4.5(a). As of their  respective dates, the WPL  SEC Reports did not
    contain any untrue statement of a material fact or omit to state a  material
    fact  required  to be  stated therein  or necessary  to make  the statements
    therein, in  light of  the circumstances  under which  they were  made,  not
    misleading.
 
        (c)  The audited consolidated financial statements and unaudited interim
    financial statements of WPL and WP&LC, as  the case may be, included in  the
    WPL  SEC Reports  (collectively, the  "WPL FINANCIAL  STATEMENTS") have been
    prepared in accordance with GAAP (except  as may be indicated therein or  in
    the  notes  thereto  and  except with  respect  to  unaudited  statements as
    permitted by Form  10-Q under the  Exchange Act) and  fairly present in  all
    material  respects the financial position  of WPL or WP&LC,  as the case may
    be, as of the dates thereof and the results of its operations and cash flows
    for the periods then  ended, subject, in the  case of the unaudited  interim
    financial statements, to normal, recurring audit adjustments.
 
        (d)  True,  accurate and  complete copies  of  the Restated  Articles of
    Incorporation and  By-laws of  WPL, as  in effect  on the  date hereof,  are
    included (or incorporated by reference) in the WPL SEC Reports.
 
    Section  4.6  ABSENCE OF CERTAIN CHANGES  OR EVENTS.  Except as disclosed in
the WPL SEC Reports filed  prior to the date hereof  or as set forth in  SECTION
4.6 of the WPL Disclosure Schedule, since December 31, 1994, WPL and each of the
WPL Subsidiaries and the WPL Joint Ventures have conducted their businesses only
in  the  ordinary course  of their  respective  businesses consistent  with past
practice and there has not  been, and no facts  or conditions exist (other  than
facts  or conditions of  general applicability to  electric utility companies in
the region in  which WPL, IES  and Interstate operate)  which, in the  aggregate
have,  or insofar  as reasonably  can be  foreseen, would  have, a  WPL Material
Adverse Effect.
 
                                      A-22
<PAGE>
    Section 4.7  LITIGATION.  Except as  disclosed in the WPL SEC Reports  filed
prior  to the date hereof or as set forth in SECTION 4.7, SECTION 4.9 or SECTION
4.11 of the WPL Disclosure Schedule,
 
        (a) there are no  claims, suits, actions or  proceedings pending or,  to
    the  knowledge of WPL, threatened,  nor are there, to  the knowledge of WPL,
    any investigations or reviews pending or threatened against, relating to  or
    affecting  WPL or any of the WPL  Subsidiaries and, to the knowledge of WPL,
    the WPL Joint Ventures;
 
        (b) there have not  been any developments since  December 31, 1994  with
    respect   to   such   disclosed   claims,   suits,   actions,   proceedings,
    investigations or reviews; and
 
        (c) there are no judgments, decrees, injunctions, rules or orders of any
    court,  governmental  department,  commission,  agency,  instrumentality  or
    authority or any arbitrator applicable to WPL or any of the WPL Subsidiaries
    and, to the knowledge of WPL, the WPL Joint Ventures,
 
which, when taken together with any other nondisclosures of matters described in
clauses  (a), (b) and (c), have, or insofar as reasonably can be foreseen, would
have, a WPL Material Adverse Effect.
 
    Section 4.8  REGISTRATION STATEMENT AND PROXY STATEMENT.
 
        (a) None of the information supplied or  to be supplied by or on  behalf
    of WPL for inclusion or incorporation by reference in:
 
           (i)  the registration statement on Form S-4  to be filed with the SEC
       by WPL in connection with the issuance  of shares of WPL Common Stock  in
       the   Merger  (the  "REGISTRATION  STATEMENT")  will,  at  the  time  the
       Registration Statement is filed with the  SEC and at the time it  becomes
       effective  under the  Securities Act, contain  any untrue  statement of a
       material fact or omit  to state any material  fact required to be  stated
       therein or necessary to make the statements therein not misleading; and
 
           (ii)  the joint proxy statement, in  definitive form, relating to the
       meetings of WPL, IES and Interstate shareholders to be held in connection
       with the Merger (the  "PROXY STATEMENT") will, at  the date(s) mailed  to
       shareholders  and at the times of the meetings of shareholders to be held
       in connection with the Merger, contain any untrue statement of a material
       fact or omit to state any material fact required to be stated therein  or
       necessary  in  order to  make  the statements  therein,  in light  of the
       circumstances under which they are made, not misleading.
 
        (b) The Registration Statement and the Proxy Statement will comply as to
    form in all material respects with the provisions of the Securities Act  and
    the  Exchange Act,  respectively, and  the applicable  rules and regulations
    thereunder.
 
    Section 4.9  TAX  MATTERS.  Except as  set forth in SECTION  4.9 of the  WPL
Disclosure Schedule:
 
        (a)  FILING OF TIMELY TAX RETURNS.  WPL and each of the WPL Subsidiaries
    have  filed (or  there has  been filed  on its  behalf) all  Tax Returns (as
    hereinafter defined) required to be filed  by each of them under  applicable
    law.  All  such Tax  Returns were  and  are in  all material  respects true,
    complete and correct and filed on a timely basis.
 
        (b)  PAYMENT  OF TAXES.   WPL  and each  of the  WPL Subsidiaries  have,
    within  the time  and in the  manner prescribed  by law, paid  all Taxes (as
    hereinafter defined) that  are currently  due and payable  except for  those
    contested in good faith and for which adequate reserves have been taken.
 
        (c)   TAX RESERVES.   WPL and  the WPL Subsidiaries  have established on
    their books and records reserves adequate to pay all Taxes and reserves  for
    deferred income taxes in accordance with GAAP.
 
        (d)  TAX LIENS.  There are no Tax liens upon the assets of WPL or any of
    the WPL Subsidiaries except liens for Taxes not yet due.
 
                                      A-23
<PAGE>
        (e)   WITHHOLDING  TAXES.   WPL and  each of  the WPL  Subsidiaries have
    complied in all material respects with  the provisions of the Code  relating
    to  the withholding of Taxes, as well  as similar provisions under any other
    laws, and  have,  within the  time  and in  the  manner prescribed  by  law,
    withheld  from  employee  wages and  paid  over to  the  proper governmental
    authorities all amounts required.
 
        (f)  EXTENSIONS OF TIME FOR FILING TAX RETURNS.  Neither WPL nor any  of
    the  WPL Subsidiaries  has requested any  extension of time  within which to
    file any Tax Return, which Tax Return has not since been timely filed.
 
        (g)  WAIVERS OF STATUTE OF LIMITATIONS.  Neither WPL nor any of the  WPL
    Subsidiaries  has executed  any outstanding  waivers or  comparable consents
    regarding the application of the statute of limitations with respect to  any
    Taxes or Tax Returns.
 
        (h)   EXPIRATION OF STATUTE OF  LIMITATIONS.  The statute of limitations
    for the assessment of all Taxes  has expired for all applicable Tax  Returns
    of  WPL and  each of  the WPL  Subsidiaries or  those Tax  Returns have been
    examined by the  appropriate taxing  authorities for all  Tax periods  ended
    before  the date hereof, and no deficiency  for any Taxes has been proposed,
    asserted or assessed against WPL or any of the WPL Subsidiaries that has not
    been resolved and paid in full.
 
        (i)  AUDIT, ADMINISTRATIVE  AND COURT PROCEEDINGS.   No audits or  other
    administrative  proceedings or court proceedings  are presently pending with
    regard to any Taxes or Tax Returns of WPL or any of the WPL Subsidiaries.
 
        (j)  POWERS OF ATTORNEY.   No power of  attorney currently in force  has
    been  granted  by WPL  or any  of  the WPL  Subsidiaries concerning  any Tax
    matter.
 
        (k)  TAX  RULINGS.   Neither WPL  nor any  of the  WPL Subsidiaries  has
    received  a Tax  Ruling (as hereinafter  defined) or entered  into a Closing
    Agreement (as hereinafter defined) with any taxing authority that would have
    a continuing adverse effect after the Closing Date.
 
        (l)  AVAILABILITY OF  TAX RETURNS.   WPL has made  available to IES  and
    Interstate  complete  and  accurate  copies  covering  the  six  years ended
    December 31, 1994 of (i) all Tax Returns, and any amendments thereto,  filed
    by  WPL or any of the WPL Subsidiaries, (ii) all audit reports received from
    any taxing authority relating to any Tax  Return filed by WPL or any of  the
    WPL  Subsidiaries, and (iii)  any Closing Agreements entered  into by WPL or
    any of the WPL Subsidiaries with any taxing authority.
 
        (m)  TAX SHARING AGREEMENTS.   Neither WPL nor  any WPL Subsidiary is  a
    party to any agreement relating to allocating or sharing of Taxes.
 
        (n)   CODE SECTION 280G.  Neither WPL nor any of the WPL Subsidiaries is
    a party to  any agreement, contract,  or arrangement that  could result,  on
    account  of the  transactions contemplated  hereunder, separately  or in the
    aggregate, in  the payment  of any  "excess parachute  payments" within  the
    meaning of Section 280G of the Code.
 
        (o)   LIABILITY FOR OTHERS.  None of  WPL or any of the WPL Subsidiaries
    has any  liability for  Taxes  of any  person other  than  WPL and  the  WPL
    Subsidiaries (i) under Treasury Regulations SECTION 1.1502-6 (or any similar
    provision of state, local or foreign law) as a transferee or successor, (ii)
    by contract, or (iii) otherwise.
 
        (p) As used in this Agreement:
 
           (i) "TAXES" means any Federal, state, county, local or foreign taxes,
       charges,  fees, levies, or  other assessments, including  all net income,
       gross income,  sales  and  use, ad  valorem,  transfer,  gains,  profits,
       excise,  franchise, real  and personal property,  gross receipts, capital
       stock,  production,  business  and  occupation,  disability,  employment,
       payroll, license,
 
                                      A-24
<PAGE>
       estimated,  stamp,  custom  duties,  severance  or  withholding  taxes or
       charges imposed by any governmental entity, and includes any interest and
       penalties (civil or criminal) on or additions to any such taxes;
 
           (ii) "TAX  RETURN"  means  a  report,  return  or  other  information
       required  to be supplied  to a governmental entity  with respect to Taxes
       including, where permitted or required, combined or consolidated  returns
       for a group of entities;
 
          (iii)  "TAX  RULING"  means a  written  ruling of  a  taxing authority
       relating to Taxes; and
 
          (iv) "CLOSING AGREEMENT" means a written and legally binding agreement
       with a taxing authority relating to Taxes.
 
    Section 4.10  EMPLOYEE MATTERS; ERISA.
 
        (a)  BENEFIT  PLANS.   SECTION 4.10(a)  of the  WPL Disclosure  Schedule
    contains  a true and complete list of each employee benefit plan, program or
    arrangement covering employees,  former employees  or directors  of WPL  and
    each  of the WPL Subsidiaries or  their beneficiaries, or providing benefits
    to such  persons  in  respect  of services  provided  to  any  such  entity,
    including,  but not limited to, employee benefit plans within the meaning of
    SECTION 3(3) of  the Employee  Retirement Income  Security Act  of 1974,  as
    amended  ("ERISA"),  and  any  severance  or  change  in  control  agreement
    (collectively, the "WPL BENEFIT  PLANS"). For the  purposes of this  SECTION
    4.10  only, the term  "WPL" shall be  deemed to include  the predecessors of
    such company.
 
        (b)  CONTRIBUTIONS.  Except as set  forth in SECTION 4.10(b) of the  WPL
    Disclosure  Schedule, all material contributions and other payments required
    to be made by WPL or any of the WPL Subsidiaries to any WPL Benefit Plan (or
    to any person pursuant to the terms thereof) have been made or the amount of
    such payment  or  contribution obligation  has  been reflected  in  the  WPL
    Financial Statements.
 
        (c)   QUALIFICATION; COMPLIANCE.  Except as set forth in SECTION 4.10(c)
    of the WPL Disclosure Schedule each of the WPL Benefit Plans intended to  be
    "QUALIFIED"  within  the meaning  of  SECTION 401(a)  of  the Code  has been
    determined by the Internal Revenue Service  (the "IRS") to be so  qualified,
    and,  to the  knowledge of WPL,  no circumstances exist  that are reasonably
    expected by WPL to result in  the revocation of any such determination.  WPL
    is  in compliance in all respects with, and each of the WPL Benefit Plans is
    and has been  operated in all  respects in compliance  with, all  applicable
    laws,  rules and  regulations governing  each such  plan, including, without
    limitation, ERISA  and the  Code, except  for any  violations that,  in  the
    aggregate do not, and insofar as reasonably can be foreseen, would not, give
    rise  to a WPL  Material Adverse Effect.  Each WPL Benefit  Plan intended to
    provide for  the  deferral of  income,  the  reduction of  salary  or  other
    compensation,  or  to  afford other  income  tax benefits,  complies  in all
    material respects with the requirements of the applicable provisions of  the
    Code  or other laws,  rules and regulations required  to provide such income
    tax benefits.
 
        (d)  LIABILITIES.  With respect  to the WPL Benefit Plans,  individually
    and  in the aggregate, no event has  occurred, and, to the knowledge of WPL,
    there does not now  exist any condition or  set of circumstances that  could
    subject  WPL or any of  the WPL Subsidiaries to  any liability arising under
    the Code, ERISA or any other applicable law (including, without  limitation,
    any   liability  of  any  kind   whatsoever,  whether  direct  or  indirect,
    contingent, inchoate or otherwise, to any  such plan or the Pension  Benefit
    Guaranty  Corporation  (the "PBGC")),  or under  any indemnity  agreement to
    which  WPL  is  subject,  which  liability,  excluding  liability  for  PBGC
    premiums,  benefit claims  and funding  obligations payable  in the ordinary
    course, has, or  insofar as reasonably  can be foreseen,  would have, a  WPL
    Material Adverse Effect.
 
        (e)   WELFARE PLANS.  Except as set  forth in SECTION 4.10(e) of the WPL
    Disclosure Schedule, none of the WPL Benefit Plans that are "WELFARE  PLANS"
    within  the  meaning of  SECTION 3(1)  of ERISA,  provides for  any benefits
    payable  to   or   on   behalf   of   any   employee   or   director   after
 
                                      A-25
<PAGE>
    termination  of  employment  or service,  as  the  case may  be,  other than
    elective continuation coverage required to  be provided under SECTION  4980B
    of  the Code or Part 6 of Title I  of ERISA or coverage which expires at the
    end of the calendar month following such event.
 
        (f)   DOCUMENTS MADE  AVAILABLE.   WPL  has made  available to  IES  and
    Interstate  a true and correct copy  of each collective bargaining agreement
    to which WPL or any of the WPL Subsidiaries is a party or under which WPL or
    any of the WPL  Subsidiaries has obligations and,  with respect to each  WPL
    Benefit Plan, where applicable,
 
           (i) such plan and summary plan description,
 
           (ii) the most recent annual report filed with the IRS,
 
          (iii)  each  related  trust  agreement,  insurance  contract,  service
       provider or investment management agreement (including all amendments  to
       each such document),
 
          (iv)  the most  recent determination  of the  IRS with  respect to the
       qualified status of such WPL Benefit Plan, and
 
           (v) the most recent actuarial report or valuation.
 
        (g)  PAYMENTS  RESULTING FROM MERGER.   Except as  set forth in  SECTION
    4.10(g) of the WPL Disclosure Schedule:
 
           (i)  The consummation or announcement of any transaction contemplated
       by this Agreement will  not (either alone or  upon the occurrence of  any
       additional or further acts or events) result in any
 
               (A)  payment (whether of severance pay or otherwise) becoming due
           from WPL or  any of the  WPL Subsidiaries to  any officer,  employee,
           former  employee  or director  thereof or  to  the trustee  under any
           "RABBI TRUST" or similar  arrangement that would  not have been  paid
           without regard to such consummation or announcement, or
 
               (B)  benefit  under any  WPL  Benefit Plan  being  established or
           becoming accelerated, vested or payable; and
 
           (ii) neither WPL nor any of the WPL Subsidiaries is a party to
 
               (A) any management, employment, deferred compensation,  severance
           (including  any payment, right or benefit  resulting from a change in
           control), bonus  or other  contract for  personal services  with  any
           officer, director or employee,
 
               (B) any consulting contract with any person who prior to entering
           into such contract was a director or officer of WPL, or
 
               (C)  any material  plan, agreement,  arrangement or understanding
           similar to any of the foregoing.
 
        (h)  LABOR AGREEMENTS.   Except as set forth  in SECTION 4.10(h) of  the
    WPL  Disclosure Schedule, as of the date  hereof, neither WPL nor any of the
    WPL Subsidiaries is a party to any collective bargaining agreement or  other
    labor  agreement with any  union or labor organization.  To the knowledge of
    WPL, as  of  the date  hereof,  there  is no  current  union  representation
    question involving employees of WPL or any of the WPL Subsidiaries, nor does
    WPL  know  of  any activity  or  proceeding  of any  labor  organization (or
    representative thereof) or  employee group to  organize any such  employees.
    Except as disclosed in the WPL SEC Reports filed prior to the date hereof or
    in SECTION 4.10(h) of the WPL Disclosure Schedule,
 
           (i)   there  is   no  material  unfair   labor  practice,  employment
       discrimination  or  other  complaint  against  WPL  or  any  of  the  WPL
       Subsidiaries pending, or to the knowledge of WPL, threatened,
 
                                      A-26
<PAGE>
           (ii)  there is  no strike, lockout  or material  dispute, slowdown or
       work stoppage pending, or to the knowledge of WPL, threatened, against or
       involving WPL or any of the WPL Subsidiaries, and
 
          (iii)  there  is  no  material  proceeding,  claim,  suit,  action  or
       governmental   investigation  pending  or,  to   the  knowledge  of  WPL,
       threatened, in respect of which any director, officer, employee or  agent
       of  WPL or  any of the  WPL Subsidiaries is  or may be  entitled to claim
       indemnification from  WPL  or  such  WPL  Subsidiary  pursuant  to  their
       respective Articles of Incorporation or By-laws.
 
    Section 4.11  ENVIRONMENTAL PROTECTION.  Except as set forth in SECTION 4.11
of the WPL Disclosure Schedule or in the WPL SEC Reports filed prior to the date
hereof:
 
        (a)  COMPLIANCE.
 
           (i) Each of WPL and the WPL Subsidiaries and WPL Joint Ventures is in
       compliance   with  all  applicable  Environmental  Laws  (as  hereinafter
       defined), except where the failure to be in compliance, in the  aggregate
       does  not, and insofar as  reasonably can be foreseen,  would not, have a
       WPL Material Adverse Effect; and
 
           (ii) neither  WPL nor  any  of the  WPL  Subsidiaries and  WPL  Joint
       Ventures has received any communication (written or oral) from any person
       or  Governmental  Authority  that alleges  that  WPL  or any  of  the WPL
       Subsidiaries and  WPL  Joint Ventures  is  not in  such  compliance  with
       applicable Environmental Laws.
 
        (b)   ENVIRONMENTAL PERMITS.   Each of WPL and  the WPL Subsidiaries has
    obtained  all  material  environmental,   health  and  safety  permits   and
    governmental  authorizations  (collectively,  the  "ENVIRONMENTAL  PERMITS")
    necessary for the construction of their facilities and the conduct of  their
    operations,  as applicable, and  all such Environmental  Permits are in good
    standing or, where applicable, a  renewal application has been timely  filed
    and  is pending  agency approval,  and WPL and  the WPL  Subsidiaries are in
    compliance with  all  terms and  conditions  of the  Environmental  Permits,
    except  where the failure  to be in  such compliance, in  the aggregate does
    not, and  insofar as  reasonably can  be  foreseen, would  not, have  a  WPL
    Material Adverse Effect.
 
        (c)  ENVIRONMENTAL CLAIMS.  There is no material Environmental Claim (as
    hereinafter defined) pending
 
           (i) against WPL or any of the WPL Subsidiaries or WPL Joint Ventures,
 
           (ii)   against  any  person   or  entity  whose   liability  for  any
       Environmental Claim WPL or  any of the WPL  Subsidiaries has or may  have
       retained or assumed either contractually or by operation of law, or
 
          (iii) against any real or personal property or operations which WPL or
       any of the WPL Subsidiaries owns, leases or manages, in whole or in part.
 
        (d)    RELEASES.   To  the knowledge  of WPL,  there  have not  been any
    material Releases (as  hereinafter defined)  of any  Hazardous Material  (as
    hereinafter  defined) that would  be reasonably likely to  form the basis of
    any material Environmental Claim against WPL or any of the WPL Subsidiaries,
    or  against  any  person  or   entity  whose  liability  for  any   material
    Environmental  Claim WPL  or any  of the  WPL Subsidiaries  has or  may have
    retained or assumed either contractually or by operation of law.
 
        (e)   PREDECESSORS.   To  the  knowledge of  WPL,  with respect  to  any
    predecessor  of WPL  or any  of the WPL  Subsidiaries, there  is no material
    Environmental Claim pending or threatened, and there has been no Release  of
    Hazardous Materials that would be reasonably likely to form the basis of any
    material Environmental Claim.
 
                                      A-27
<PAGE>
        (f)   DISCLOSURE.  To WPL's knowledge,  WPL has disclosed to each of IES
    and Interstate all  material facts  which WPL reasonably  believes form  the
    basis of a material Environmental Claim arising from
 
           (i) the cost of WPL pollution control equipment currently required or
       known to be required in the future;
 
           (ii)  current WPL remediation costs or WPL remediation costs known to
       be required in the future; or
 
          (iii)  any  other  environmental  matter  affecting  WPL  or  the  WPL
       Subsidiaries or WPL Joint Ventures.
 
        (g) As used in this Agreement:
 
           (i)   "ENVIRONMENTAL  CLAIM"   means  any   and  all  administrative,
       regulatory  or  judicial   actions,  suits,   demands,  demand   letters,
       directives,  claims,  liens,  investigations, proceedings  or  notices of
       noncompliance, liability or violation (written or oral) by any person  or
       entity   (including  any   Governmental  Authority)   alleging  potential
       liability (including,  without  limitation, potential  responsibility  or
       liability   for   enforcement,   investigatory   costs,   cleanup  costs,
       governmental response  costs,  removal  costs,  remedial  costs,  natural
       resources  damages,  property  damages, personal  injuries  or penalties)
       arising out of, based on or resulting from
 
               (A) the  presence,  or Release  or  threatened Release  into  the
           environment,  of any Hazardous Materials  at any location, whether or
           not owned,  operated, leased  or managed  by WPL  or any  of the  WPL
           Subsidiaries  or  WPL Joint  Ventures (for  purposes of  this SECTION
           4.11), or by IES or any of the IES Subsidiaries or IES Joint Ventures
           (as hereinafter  defined)  (for  purposes  of  SECTION  5.11)  or  by
           Interstate  or any of the Interstate Subsidiaries or Interstate Joint
           Ventures (as hereinafter defined) (for the purposes of SECTION 6.11);
           or
 
               (B) circumstances forming the basis of any violation, or  alleged
           violation, of any Environmental Law; or
 
               (C)  any  and  all claims  by  any third  party  seeking damages,
           contribution,  indemnification,   cost  recovery,   compensation   or
           injunctive  relief  resulting from  the  presence or  Release  of any
           Hazardous Materials;
 
           (ii) "ENVIRONMENTAL LAWS"  means all Federal,  state and local  laws,
       rules  and regulations relating to pollution, the environment (including,
       without limitation, ambient air, surface water, groundwater, land surface
       or subsurface strata) or protection of human health as it relates to  the
       environment  including, without limitation, laws and regulations relating
       to Releases or threatened Releases  of Hazardous Materials, or  otherwise
       relating  to the  manufacture, processing,  distribution, use, treatment,
       storage, disposal, transport or handling of Hazardous Materials;
 
          (iii) "HAZARDOUS  MATERIALS"  means  (a) any  petroleum  or  petroleum
       products,  radioactive materials, asbestos  in any form  that is or could
       become friable, urea  formaldehyde foam insulation,  and transformers  or
       other  equipment that contain dielectric fluid containing polychlorinated
       biphenyls; and (b) any chemicals,  materials or substances which are  now
       defined  as  or included  in  the definition  of  "HAZARDOUS SUBSTANCES,"
       "HAZARDOUS WASTES," "HAZARDOUS MATERIALS," "EXTREMELY HAZARDOUS  WASTES,"
       "RESTRICTED HAZARDOUS WASTES," "TOXIC SUBSTANCES," "TOXIC POLLUTANTS," or
       words  of similar import, under any  Environmental Law; and (c) any other
       chemical,  material,  substance  or  waste,  exposure  to  which  is  now
       prohibited,  limited  or  regulated  under  any  Environmental  Law  in a
       jurisdiction in which WPL or
 
                                      A-28
<PAGE>
       any of the WPL Subsidiaries or WPL Joint Ventures operates (for  purposes
       of  this SECTION 4.11) or in which IES  or any of the IES Subsidiaries or
       IES Joint Ventures operates  (for purposes of SECTION  5.11) or in  which
       Interstate  or  any of  the Interstate  Subsidiaries or  Interstate Joint
       Ventures operates (for purposes of SECTION 6.11); and
 
          (iv) "RELEASE" means any release, spill, emission, leaking, injection,
       deposit, disposal, discharge, dispersal,  leaching or migration into  the
       atmosphere, soil, surface water, groundwater or property.
 
    Section  4.12  REGULATION AS A UTILITY.  (a)  WP&LC is regulated as a public
utility in the  State of Wisconsin  and in no  other state. WP&LC's  Subsidiary,
South  Beloit Water,  Gas and  Electric Company,  an Illinois  corporation, is a
public utility  supplying  electric,  gas  and  water  service,  principally  in
Winnebago  County, Illinois.  Except as  set forth  in SECTION  4.12 of  the WPL
Disclosure Schedule, neither WPL nor any "SUBSIDIARY COMPANY" or "AFFILIATE"  of
WPL  is subject to regulation as a  public utility or public service company (or
similar designation) by  any other  state in the  United States  or any  foreign
country. WPL is an exempt holding company under SECTION 3(a)(1) of the 1935 Act.
 
    (b)  As used in this  SECTION 4.12 and in SECTIONS  5.12 and 6.12, the terms
"SUBSIDIARY COMPANY" and "AFFILIATE" shall have the respective meanings ascribed
to them in the 1935 Act.
 
    Section 4.13  VOTE REQUIRED.  The  approval by the holders of a majority  of
the  votes entitled  to be  cast by all  holders of  WPL Common  Stock (the "WPL
SHAREHOLDERS' APPROVAL") to approve the IES  Merger, the issuance of the  shares
of  WPL Common Stock  in the Merger  and the charter  amendments as described in
SECTION 8.19 of the WPL Disclosure Schedule  is the only vote of the holders  of
any  class  or series  of  the capital  stock  of WPL  required  for any  of the
transactions contemplated by this  Agreement or the  Stock Option Agreements  to
which  WPL is a party;  PROVIDED, HOWEVER, that the  approval of shareholders of
WPL may be required for the repurchase of shares of WPL Common Stock pursuant to
SECTION 8(a) of each of the  WPL/IES and WPL/Interstate Stock Option  Agreements
under circumstances where SECTION 180.1134 of the WBCL would be applicable.
 
    Section 4.14  ACCOUNTING MATTERS.
 
        (a)  Neither  WPL nor,  to WPL's  knowledge, any  of its  Affiliates (as
    hereinafter defined)  has taken  or agreed  to take  any action  that  would
    prevent  WPL from accounting for the transactions to be effected pursuant to
    this Agreement  as  a pooling  of  interests  in accordance  with  GAAP  and
    applicable SEC regulations.
 
        (b)  As  used  in  this  Agreement  (except  as  specifically  otherwise
    defined):
 
           (i) "AFFILIATE"  means, as  to  any person,  any other  person  which
       directly  or indirectly controls, or is  under common control with, or is
       controlled by, such person; and
 
           (ii) "CONTROL" (including, with its correlative meanings, "CONTROLLED
       BY" and  "UNDER  COMMON  CONTROL WITH")  means  possession,  directly  or
       indirectly,  of power to  direct or cause the  direction of management or
       policies (whether through ownership of securities or partnership or other
       ownership interests, by contract or otherwise).
 
    Section  4.15    APPLICABILITY  OF  CERTAIN  PROVISIONS  OF  WISCONSIN  LAW,
ETC.   Assuming the representations and warranties of IES and Interstate made in
SECTIONS 5.18 and 6.18,  respectively, are correct, none  of the "CONTROL  SHARE
VOTING"  provisions of SECTION 180.1150 of  the WBCL, the "BUSINESS COMBINATION"
provisions of  SECTIONS 180.1140  to  180.1144 of  the  WBCL, the  "FAIR  PRICE"
provisions  of SECTIONS 180.1130 to 180.1133 of  the WBCL, or any other takeover
related provisions of the WBCL (or, to  the knowledge of WPL, any other  similar
state  statute) or the Restated Articles of Incorporation or By-laws of WPL, are
applicable to the  transactions contemplated  by this  Agreement, including  the
granting  or exercise of the WPL/IES  and WPL/Interstate Stock Option Agreements
(except as set forth in SECTION 4.15 of the WPL Disclosure Schedule).
 
                                      A-29
<PAGE>
    Section  4.16  OPINION OF FINANCIAL ADVISOR.  As of the date hereof, WPL has
received the opinion of Merrill Lynch & Co. ("MERRILL"), to the effect that,  as
of  the date hereof, the IES Ratio and the Interstate Ratio are fair to WPL from
a financial point of view.
 
    Section 4.17  INSURANCE.   Except as  set forth in SECTION  4.17 of the  WPL
Disclosure  Schedule, each  of WPL  and the  WPL Subsidiaries  is, and  has been
continuously  since  January  1,  1990,  insured  with  financially  responsible
insurers  in such amounts and against such  risks and losses as are customary in
all material respects for companies conducting the business conducted by WPL and
the WPL Subsidiaries  during such time  period. Except as  set forth in  SECTION
4.17 of the WPL Disclosure Schedule, neither WPL nor any of the WPL Subsidiaries
has  received  any notice  of cancellation  or termination  with respect  to any
material insurance policy of WPL or  any of the WPL Subsidiaries. The  insurance
policies  of WPL  and each  of the  WPL Subsidiaries  are valid  and enforceable
policies in all material respects.
 
    Section 4.18  OWNERSHIP OF IES AND  INTERSTATE COMMON STOCK.  Except as  set
forth in SECTION 4.18 of the WPL Disclosure Schedule, and except pursuant to the
terms  of the IES/WPL Stock Option Agreement and the Interstate/WPL Stock Option
Agreement, WPL does not "BENEFICIALLY OWN" (as such term is defined for purposes
of SECTION  13(d)  of the  Exchange  Act) any  shares  of IES  Common  Stock  or
Interstate Common Stock.
 
    Section  4.19    WPL  RIGHTS  AGREEMENT.    Assuming  the  accuracy  of  the
representations contained in  SECTIONS 5.18  and 6.18, the  consummation of  the
transactions contemplated by this Agreement will not result in the triggering of
any right or entitlement of WPL shareholders under the WPL Rights Agreement.
 
    Section  4.20  OPERATIONS  OF NUCLEAR POWER  PLANT.  Except  as set forth in
SECTION 4.20 of  the WPL  Disclosure Schedule,  the operations  of the  Kewaunee
Nuclear  Facility  ("KEWAUNEE") owned  by  WPL (together  with  Wisconsin Public
Service Corporation ("WPS") and  Madison Gas & Electric  Company, as tenants  in
common) and operated by WPS, have at all times been conducted in compliance with
applicable health, safety, regulatory and other legal requirements, except where
the  failure to be in  compliance in the aggregate does  not, and insofar as can
reasonably be foreseen, would not, have a WPL Material Adverse Effect.  Kewaunee
maintains  emergency  plans designed  to respond  to  an unplanned  release from
Kewaunee of  radioactive materials  into  the environment.  Customary  liability
insurance  consistent with industry  practice and consistent  with WPL's view of
the risks inherent in the operation of a nuclear power facility currently exists
with respect to Kewaunee. Plans for the decommissioning of Kewaunee and for  the
short-term  storage  of  spent nuclear  fuel  conform with  the  requirements of
applicable law, and such plans have  at all times been funded consistently  with
budget projections for such plans.
 
                                   ARTICLE V
                     REPRESENTATIONS AND WARRANTIES OF IES
 
    IES represents and warrants to WPL and Interstate as follows:
 
    Section 5.1  ORGANIZATION AND QUALIFICATION.  Except as set forth in SECTION
5.1  of the Disclosure Schedule to this  Agreement prepared and delivered by IES
(the "IES  DISCLOSURE SCHEDULE"),  each  of IES  and  the IES  Subsidiaries  (as
hereinafter  defined) is a  corporation duly organized,  validly existing and in
good standing  (to  the extent  applicable  under  the laws  of  its  respective
jurisdiction of incorporation or organization, has all requisite corporate power
and  authority,  and has  been duly  authorized by  all necessary  approvals and
orders to own, lease and operate its assets and properties to the extent  owned,
leased  and operated and to  carry on its business as  it is now being conducted
and is duly  qualified and in  good standing  (to the extent  applicable) to  do
business  in each respective jurisdiction in which the nature of its business or
the ownership or leasing of its  assets and properties makes such  qualification
necessary, other than in such jurisdictions where the failure to be so qualified
and  in  good  standing would  not,  when  taken together  with  all  other such
failures, have a material adverse effect
 
                                      A-30
<PAGE>
on  the  business,  operations,  properties,  assets,  condition  (financial  or
otherwise),  or the results of operations of  IES and the IES Subsidiaries taken
as a whole  or on the  consummation of the  transaction contemplated hereby  (an
"IES MATERIAL ADVERSE EFFECT").
 
    Section 5.2  SUBSIDIARIES.
 
        (a)  SECTION 5.2 of the IES Disclosure Schedule sets forth a description
    as of  the date  hereof, of  all IES  Subsidiaries and  IES Joint  Ventures,
    including  (i) the name of each such  entity and IES's interest therein, and
    (ii) a  brief  description  of  the principal  line  or  lines  of  business
    conducted by each such entity.
 
        (b)  Except as set forth in SECTION  5.2 of the IES Disclosure Schedule,
    none of  the IES  Subsidiaries is  a "PUBLIC  UTILITY COMPANY,"  a  "HOLDING
    COMPANY,"  a "SUBSIDIARY  COMPANY" or an  "AFFILIATE" of  any public utility
    company within the meaning of SECTION 2(a)(5), 2(a)(7), 2(a)(8) or  2(a)(11)
    of the 1935 Act, respectively.
 
        (c)  Except as set forth in SECTION  5.2 of the IES Disclosure Schedule,
    all of  the issued  and outstanding  shares  of capital  stock of  each  IES
    Subsidiary  are duly  authorized, validly issued,  fully paid, nonassessable
    and free of preemptive rights, and are owned, directly or indirectly, by IES
    free and  clear  of any  liens,  claims, encumbrances,  security  interests,
    equities,  charges and  options of any  nature whatsoever, and  there are no
    outstanding subscriptions, options, calls, contracts, voting trusts, proxies
    or other commitments, understandings, restrictions, arrangements, rights  or
    warrants,   including  any  right  of   conversion  or  exchange  under  any
    outstanding security, instrument or other agreement, obligating any such IES
    Subsidiary to issue, deliver  or sell, or cause  to be issued, delivered  or
    sold,  additional shares  of its  capital stock,  or granting  to any person
    other than  IES  or  an IES  Subsidiary  any  right to  participate  in  its
    dividends  or earnings or obligating  it to grant, extend  or enter into any
    such agreement or commitment.
 
        (d) As used in this Agreement,
 
           (i) "IES SUBSIDIARY" shall mean any Subsidiary of IES; and
 
           (ii) "IES JOINT VENTURE" shall mean  any Joint Venture of IES or  any
       IES Subsidiary.
 
    Section 5.3  CAPITALIZATION.
 
        (a) The authorized capital stock of IES consists of
 
           (i)  48,000,000 shares of IES Common Stock of which 29,345,573 shares
       were issued and outstanding as of September 30, 1995, and
 
           (ii) 5,000,000 shares of IES Cumulative Preferred Stock, no par value
       ("IES PREFERRED STOCK"), of which none  were issued or outstanding as  of
       September 30, 1995.
 
        (b)  The  authorized capital  stock of  IES's Subsidiary,  IES Utilities
    Inc., an Iowa corporation ("UTILITIES") consists of
 
           (i) 24,000,000 shares of common stock,  par value $2.50 per share  of
       which  13,370,788 shares were issued and  outstanding as of September 30,
       1995 ("UTILITIES COMMON STOCK"),
 
           (ii) 466,406  shares of  Cumulative Preferred  Stock, $50  par  value
       (4.30%  series, 4.80% series,  and 6.10% series) of  which 120,000 of the
       4.30% series,  146,354 of  the 4.80%  series, and  100,000 of  the  6.10%
       series  were issued and outstanding as  of September 30, 1995 ("UTILITIES
       PREFERRED STOCK"), and
 
          (iii) 700,000 shares of Cumulative  Preference Stock, $100 par  value,
       of which none were outstanding as of September 30, 1995.
 
                                      A-31
<PAGE>
        (c)  All  of the  issued  and outstanding  shares  of IES  Common Stock,
    Utilities Common Stock and Utilities Preferred Stock are, and any shares  of
    IES  Common Stock  issued pursuant to  the IES/WPL  and IES/Interstate Stock
    Option Agreements  will be,  duly authorized,  validly issued,  fully  paid,
    nonassessable and free of preemptive rights.
 
        (d)  Except as set forth in SECTION  5.3 of the IES Disclosure Schedule,
    as of  the date  hereof, there  are no  outstanding subscriptions,  options,
    calls,   contracts,   voting   trusts,   proxies   or   other   commitments,
    understandings, restrictions,  arrangements, rights  or warrants,  including
    any  right  of  conversion  or  exchange  under  any  outstanding  security,
    instrument or other agreement, obligating IES or any of the IES Subsidiaries
    to issue,  deliver  or sell,  or  cause to  be  issued, delivered  or  sold,
    additional  shares of the capital stock of  IES, or obligating IES to grant,
    extend or enter into any such agreement or commitment, other than under  the
    IES/WPL and IES/ Interstate Stock Option Agreements.
 
    Section 5.4  AUTHORITY; NON-CONTRAVENTION; STATUTORY APPROVALS; COMPLIANCE.
 
        (a)   AUTHORITY.  IES has all requisite corporate power and authority to
    enter into this Agreement  and the IES/WPL  and IES/Interstate Stock  Option
    Agreements,  and, subject to  the applicable IES  Shareholders' Approval (as
    hereinafter defined) and the applicable IES Required Statutory Approvals (as
    hereinafter defined), to consummate the transactions contemplated hereby  or
    thereby.  The execution and  delivery of this Agreement  and the IES/WPL and
    IES/ Interstate Stock Option Agreements and  the consummation by IES of  the
    transactions  contemplated hereby and  thereby have been  duly authorized by
    all necessary corporate action on the part of IES, subject to obtaining  the
    applicable  IES  Shareholders'  Approval.  Each of  this  Agreement  and the
    IES/WPL and IES/Interstate Stock Option Agreements has been duly and validly
    executed and delivered by IES and, assuming the due authorization, execution
    and delivery hereof and thereof by the other signatories hereto and thereto,
    constitutes the valid and binding  obligation of IES enforceable against  it
    in  accordance  with  its terms,  except  as  may be  limited  by applicable
    bankruptcy, insolvency, reorganization or  other similar laws affecting  the
    enforcement of creditors' rights generally, and except that the availability
    of equitable remedies, including specific performance, may be subject to the
    discretion of any court before which any proceeding therefor may be brought.
 
        (b)   NON-CONTRAVENTION.  Except  as set forth in  SECTION 5.4(b) of the
    IES Disclosure Schedule, the  execution and delivery  of this Agreement  and
    the  IES/WPL and IES/Interstate  Stock Option Agreements by  IES do not, and
    the consummation of  the transactions  contemplated hereby  or thereby  will
    not, result in a Violation pursuant to any provisions of:
 
           (i)  the  Articles  of Incorporation,  By-laws  or  similar governing
       documents of  IES  or  any of  the  IES  Subsidiaries or  the  IES  Joint
       Ventures;
 
           (ii)  subject to obtaining  the IES Required  Statutory Approvals and
       the  receipt  of  the  IES  Shareholders'  Approval,  any  statute,  law,
       ordinance,  rule, regulation, judgment,  decree, order, injunction, writ,
       permit or license of any Governmental Authority applicable to IES or  any
       of  IES Subsidiaries  or IES  Joint Ventures  or any  of their respective
       properties or assets, or
 
          (iii) subject  to  obtaining the  third-party  consents set  forth  in
       SECTION  5.4(b)  of  the  IES  Disclosure  Schedule  (the  "IES  REQUIRED
       CONSENTS"), any material note, bond, mortgage, indenture, deed of  trust,
       license,   franchise,  permit,  concession,   contract,  lease  or  other
       instrument, obligation or agreement  of any kind to  which IES or any  of
       the  IES Subsidiaries or IES Joint Ventures is  a party or by which it or
       any of its properties or assets may be bound or affected,
 
    excluding from the foregoing clauses  (ii) and (iii) such violations  which,
    in  the aggregate do not,  and insofar as reasonably  can be foreseen, would
    not, have an IES Material Adverse Effect.
 
                                      A-32
<PAGE>
        (c)  STATUTORY APPROVALS.  No declaration, filing or registration  with,
    or  notice to  or authorization,  consent or  approval of,  any Governmental
    Authority is necessary for the execution  and delivery of this Agreement  or
    the  IES/WPL  and  IES/Interstate  Stock Option  Agreements  by  IES  or the
    consummation by  IES of  the transactions  contemplated hereby  or  thereby,
    except  as described in  SECTION 5.4(c) of the  IES Disclosure Schedule (the
    "IES REQUIRED STATUTORY APPROVALS", it  being understood that references  in
    this  Agreement to "OBTAINING"  such IES Required  Statutory Approvals shall
    mean  making  such  declarations,  filings  or  registrations;  giving  such
    notices;  obtaining such  authorizations, consents or  approvals; and having
    such waiting periods expire as are necessary to avoid a violation of law).
 
        (d)  COMPLIANCE.
 
           (i) Except as set  forth in SECTION 5.4(d),  SECTION 5.10 or  SECTION
       5.11  of the  IES Disclosure  Schedule, or  as disclosed  in the  IES SEC
       Reports (as hereinafter defined) filed prior to the date hereof,  neither
       IES nor any of the IES Subsidiaries nor, to the knowledge of IES, any IES
       Joint Venture, is in violation of, is under investigation with respect to
       any  violation of,  or has  been given  notice or  been charged  with any
       violation of, any  law, statute,  order, rule,  regulation, ordinance  or
       judgment  (including,  without limitation,  any  applicable environmental
       law, ordinance or regulation) of  any Governmental Authority, except  for
       violations  which, in the aggregate do not, and insofar as reasonably can
       be foreseen, would not, have an IES Material Adverse Effect.
 
           (ii) Except as set forth in SECTION 5.4(d) or in SECTION 5.11 of  the
       IES  Disclosure  Schedule, IES  and the  IES  Subsidiaries and  IES Joint
       Ventures have  all  Permits  necessary to  conduct  their  businesses  as
       presently  conducted, except those the failure of which to obtain, in the
       aggregate do not, and insofar as  reasonably can be foreseen, would  not,
       have an IES Material Adverse Effect.
 
          (iii)  Except as  set forth  in SECTION  5.4(d) of  the IES Disclosure
       Schedule, each of IES and the IES Subsidiaries and IES Joint Ventures  is
       not  in breach, violation, or default in the performance or observance of
       any term or provision of, and no event has occurred which, with lapse  of
       time or action by a third party, could result in a default under,
 
               (A) its Articles of Incorporation or By-laws, or
 
               (B)  any  contract, commitment,  agreement,  indenture, mortgage,
           loan  agreement,  note,  lease,  bond,  license,  approval  or  other
           instrument to which it is a party or by which it is bound or to which
           any  of its property  is subject, except  for breaches, violations or
           defaults which, in the  aggregate do not,  and insofar as  reasonably
           can be foreseen, would not, have an IES Material Adverse Effect.
 
    Section 5.5  REPORTS AND FINANCIAL STATEMENTS.
 
        (a)  The filings  required to  be made by  IES and  the IES Subsidiaries
    since January 1, 1992 under the  Securities Act, the Exchange Act, the  1935
    Act,  the Power  Act, the  Atomic Energy Act  and applicable  state laws and
    regulations have been filed with the SEC, the FERC, the NRC, the DOE or  any
    appropriate state public utilities commission, as the case may be, including
    all  forms,  statements,  reports,  agreements  (oral  or  written)  and all
    documents, exhibits, amendments  and supplements  appertaining thereto,  and
    complied,  as of their  respective dates, in all  material respects with all
    applicable requirements  of  the  appropriate  statute  and  the  rules  and
    regulations thereunder.
 
        (b)  IES has made  available to WPL  and Interstate a  true and complete
    copy of each form, report,  schedule, registration statement and  definitive
    proxy  statement  filed by  each of  IES  and Utilities  with the  SEC since
    January 1, 1992 (as such documents have since the time of their filing  been
    amended  or  supplemented,  the "IES  SEC  REPORTS") and  each  other filing
    described in  SECTION 5.5(a).  As of  their respective  dates, the  IES  SEC
    Reports did not contain any untrue
 
                                      A-33
<PAGE>
    statement of a material fact or omit to state a material fact required to be
    stated  therein or necessary to make the statements therein, in light of the
    circumstances under which they were made, not misleading.
 
        (c) The audited consolidated financial statements and unaudited  interim
    financial  statements of IES and Utilities, as  the case may be, included in
    the IES SEC Reports (collectively, the "IES FINANCIAL STATEMENTS") have been
    prepared in accordance with GAAP (except  as may be indicated therein or  in
    the  notes  thereto  and  except with  respect  to  unaudited  statements as
    permitted by Form  10-Q under the  Exchange Act) and  fairly present in  all
    material  respects the financial  position of IES or  Utilities, as the case
    may be, as of the dates thereof  and the results of its operations and  cash
    flows  for the  periods then  ended, subject, in  the case  of the unaudited
    interim financial statements, to normal, recurring audit adjustments.
 
        (d) True,  accurate and  complete  copies of  the Restated  Articles  of
    Incorporation  and By-laws  of IES,  as in  effect on  the date  hereof, are
    included (or incorporated by reference) in the IES SEC Reports.
 
    Section 5.6  ABSENCE OF CERTAIN CHANGES  OR EVENTS.  Except as disclosed  in
the  IES SEC Reports filed prior  to the date hereof or  as set forth in SECTION
5.6 of the IES Disclosure Schedule, since December 31, 1994, IES and each of the
IES Subsidiaries and IES Joint Ventures have conducted their businesses only  in
the ordinary course of their respective businesses consistent with past practice
and  there has not been,  and no facts or conditions  exist (other than facts or
conditions of general applicability to electric utility companies in the  region
in  which WPL,  IES and  Interstate operate)  which, in  the aggregate  have or,
insofar as  reasonably can  be foreseen,  would have,  an IES  Material  Adverse
Effect.
 
    Section  5.7  LITIGATION.  Except as  disclosed in the IES SEC Reports filed
prior to the date hereof or as set forth in SECTION 5.7, SECTION 5.9 or  SECTION
5.11 of the IES Disclosure Schedule,
 
        (a)  there are no  claims, suits, actions or  proceedings pending or, to
    the knowledge of IES,  threatened, nor are there,  to the knowledge of  IES,
    any  investigations or reviews pending or threatened against, relating to or
    affecting IES or any of the IES  Subsidiaries and, to the knowledge of  IES,
    the IES Joint Ventures;
 
        (b)  there have not  been any developments since  December 31, 1994 with
    respect   to   such   disclosed   claims,   suits,   actions,   proceedings,
    investigations or reviews; and
 
        (c) there are no judgments, decrees, injunctions, rules or orders of any
    court,  governmental  department,  commission,  agency,  instrumentality  or
    authority or any arbitrator applicable to IES or any of the IES Subsidiaries
    and, to the knowledge of IES, or the IES Joint Ventures,
 
which, when taken together with any other nondisclosures of matters described in
clauses (a), (b) and (c), have, or insofar as reasonably can be foreseen,  would
have, an IES Material Adverse Effect.
 
    Section 5.8  REGISTRATION STATEMENT AND PROXY STATEMENT.
 
        (a)  None of the information supplied or  to be supplied by or on behalf
    of IES for inclusion or incorporation by reference in:
 
           (i) the Registration  Statement will,  at the  time the  Registration
       Statement  is filed  with the  SEC and at  the time  it becomes effective
       under the Securities Act, contain any untrue statement of a material fact
       or omit  to state  any material  fact required  to be  stated therein  or
       necessary to make the statements therein, not misleading, and
 
           (ii) the Proxy Statement will, at the date mailed to shareholders and
       at  the times of  the meetings of  shareholders to be  held in connection
       with the IES Merger, contain any  untrue statement of a material fact  or
       omit  to  state  any  material  fact required  to  be  stated  therein or
       necessary in  order to  make  the statements  therein,  in light  of  the
       circumstances under which they are made, not misleading.
 
                                      A-34
<PAGE>
        (b) The Registration Statement and the Proxy Statement will comply as to
    form  in all material respects with the provisions of the Securities Act and
    the Exchange Act,  respectively, and  the applicable  rules and  regulations
    thereunder.
 
    Section  5.9  TAX  MATTERS.  Except as  set forth in SECTION  5.9 of the IES
Disclosure Schedule:
 
        (a)  FILING OF TIMELY TAX RETURNS.  IES and each of the IES Subsidiaries
    have filed (or there has been filed on its behalf) all Tax Returns  required
    to  be filed by each of them under applicable law. All such Tax Returns were
    and are in all material respects true,  complete and correct and filed on  a
    timely basis.
 
        (b)   PAYMENT  OF TAXES.   IES  and each  of the  IES Subsidiaries have,
    within the time and in the manner prescribed by law, paid all Taxes that are
    currently due and payable except for  those contested in good faith and  for
    which adequate reserves have been taken.
 
        (c)   TAX RESERVES.   IES and  the IES Subsidiaries  have established on
    their books and records reserves adequate to pay all Taxes and reserves  for
    deferred income taxes in accordance with GAAP.
 
        (d)  TAX LIENS.  There are no Tax liens upon the assets of IES or any of
    the IES Subsidiaries except liens for Taxes not yet due.
 
        (e)   WITHHOLDING  TAXES.   IES and  each of  the IES  Subsidiaries have
    complied in all material respects with  the provisions of the Code  relating
    to  the withholding of Taxes, as well  as similar provisions under any other
    laws, and  have,  within the  time  and in  the  manner prescribed  by  law,
    withheld  from  employee  wages and  paid  over to  the  proper governmental
    authorities all amounts required.
 
        (f)  EXTENSIONS OF TIME FOR FILING TAX RETURNS.  Neither IES nor any  of
    the  IES Subsidiaries  has requested any  extension of time  within which to
    file any Tax Return, which Tax Return has not since been timely filed.
 
        (g)  WAIVERS OF STATUTE OF LIMITATIONS.  Neither IES nor any of the  IES
    Subsidiaries  has executed  any outstanding  waivers or  comparable consents
    regarding the application of the statute of limitations with respect to  any
    Taxes or Tax Returns.
 
        (h)   EXPIRATION OF STATUTE OF  LIMITATIONS.  The statute of limitations
    for the assessment of all Taxes  has expired for all applicable Tax  Returns
    of  IES and  each of  the IES  Subsidiaries or  those Tax  Returns have been
    examined by the  appropriate taxing  authorities for all  Tax periods  ended
    before  the date hereof, and no deficiency  for any Taxes has been proposed,
    asserted or assessed against IES or any of the IES Subsidiaries that has not
    been resolved and paid in full.
 
        (i)  AUDIT, ADMINISTRATIVE  AND COURT PROCEEDINGS.   No audits or  other
    administrative  proceedings or court proceedings  are presently pending with
    regard to any Taxes or Tax Returns of IES or any of the IES Subsidiaries.
 
        (j)  POWERS OF ATTORNEY.   No power of  attorney currently in force  has
    been  granted  by IES  or any  of  the IES  Subsidiaries concerning  any Tax
    matter.
 
        (k)  TAX  RULINGS.   Neither IES  nor any  of the  IES Subsidiaries  has
    received  a Tax Ruling or  entered into a Closing  Agreement with any taxing
    authority that  would have  a continuing  adverse effect  after the  Closing
    Date.
 
        (l)   AVAILABILITY OF  TAX RETURNS.   IES has made  available to WPL and
    Interstate complete  and  accurate  copies  covering  the  six  years  ended
    December  31, 1994 of (i) all Tax Returns, and any amendments thereto, filed
    by IES or any of the IES Subsidiaries, (ii) all audit reports received  from
    any  taxing authority relating to any Tax Return  filed by IES or any of the
    IES Subsidiaries, and (iii)  any Closing Agreements entered  into by IES  or
    any of the IES Subsidiaries with any taxing authority.
 
                                      A-35
<PAGE>
        (m)   TAX SHARING AGREEMENTS.   Neither IES nor  any IES Subsidiary is a
    party to any agreement relating to allocating or sharing of Taxes.
 
        (n)  CODE SECTION 280G.   Except as set forth  in SECTION 5.9(n) of  the
    IES  Disclosure Schedule, neither IES  nor any of the  IES Subsidiaries is a
    party to  any agreement,  contract,  or arrangement  that could  result,  on
    account  of the  transactions contemplated  hereunder, separately  or in the
    aggregate, in  the payment  of any  "EXCESS PARACHUTE  PAYMENTS" within  the
    meaning of SECTION 280G of the Code.
 
        (o)   LIABILITY FOR OTHERS.  None of  IES or any of the IES Subsidiaries
    has any  liability for  Taxes  of any  person other  than  IES and  the  IES
    Subsidiaries (i) under Treasury Regulations SECTION 1.1502-6 (or any similar
    provision of state, local or foreign law) as a transferee or successor, (ii)
    by contract, or (iii) otherwise.
 
    Section 5.10  EMPLOYEE MATTERS; ERISA.
 
        (a)   BENEFIT  PLANS.   SECTION 5.10(a)  of the  IES Disclosure Schedule
    contains a true and complete list of each employee benefit plan, program  or
    arrangement  covering employees,  former employees  or directors  of IES and
    each of the IES Subsidiaries  or their beneficiaries, or providing  benefits
    to  such  persons  in  respect  of services  provided  to  any  such entity,
    including, but not limited to, employee benefit plans within the meaning  of
    SECTION  3(3)  of ERISA  and any  severance or  change in  control agreement
    (collectively, the "IES BENEFIT  PLANS"). For the  purposes of this  SECTION
    5.10  only, the term  "IES" shall be  deemed to include  the predecessors of
    such company.
 
        (b)  CONTRIBUTIONS.  Except as set  forth in SECTION 5.10(b) of the  IES
    Disclosure  Schedule, all material contributions and other payments required
    to be made by IES or any of the IES Subsidiaries to any IES Benefit Plan (or
    to any person pursuant to the terms thereof) have been made or the amount of
    such payment  or  contribution obligation  has  been reflected  in  the  IES
    Financial Statements.
 
        (c)   QUALIFICATION; COMPLIANCE.  Except as set forth in SECTION 5.10(c)
    of the IES Disclosure Schedule, each of the IES Benefit Plans intended to be
    "QUALIFIED" within  the meaning  of  SECTION 401(a)  of  the Code  has  been
    determined  by the IRS to be so qualified,  and, to the knowledge of IES, no
    circumstances exist that  are reasonably expected  by IES to  result in  the
    revocation  of any such determination. IES  is in compliance in all respects
    with, and each  of the IES  Benefit Plans is  and has been  operated in  all
    respects  in  compliance with,  all applicable  laws, rules  and regulations
    governing each such plan, including, without limitation, ERISA and the Code,
    except for any  violations that,  in the aggregate  do not,  and insofar  as
    reasonably  can be foreseen, would not, give rise to an IES Material Adverse
    Effect. Each  IES Benefit  Plan  intended to  provide  for the  deferral  of
    income,  the reduction of  salary or other compensation,  or to afford other
    income tax benefits, complies in all material respects with the requirements
    of  the  applicable  provisions  of  the  Code  or  other  laws,  rules  and
    regulations required to provide such income tax benefits.
 
        (d)   LIABILITIES.  With respect  to the IES Benefit Plans, individually
    and in the aggregate, no event has  occurred, and, to the knowledge of  IES,
    there  does not now exist  any condition or set  of circumstances that could
    subject IES or any  of the IES Subsidiaries  to any liability arising  under
    the  Code, ERISA or any other applicable law (including, without limitation,
    any  liability  of  any  kind   whatsoever,  whether  direct  or   indirect,
    contingent,  inchoate or otherwise, to any such  plan or the PBGC), or under
    any indemnity agreement to which IES is subject, which liability,  excluding
    liability  for PBGC premiums, benefit claims and funding obligations payable
    in the ordinary course, has, or insofar as reasonably can be foreseen, would
    have, an IES Material Adverse Effect.
 
        (e)  WELFARE PLANS.  Except as  set forth in SECTION 5.10(e) of the  IES
    Disclosure  Schedule, none of the IES Benefit Plans that are "WELFARE PLANS"
    within the  meaning of  SECTION 3(1)  of ERISA,  provides for  any  benefits
    payable   to   or   on   behalf   of   any   employee   or   director  after
 
                                      A-36
<PAGE>
    termination of  employment  or service,  as  the  case may  be,  other  than
    elective  continuation coverage required to  be provided under SECTION 4980B
    of the Code or Part 6 of Title  I of ERISA or coverage which expires at  the
    end of the calendar month following such event.
 
        (f)    DOCUMENTS MADE  AVAILABLE.   IES  has made  available to  WPL and
    Interstate a true and correct  copy of each collective bargaining  agreement
    to which IES or any of the IES Subsidiaries is a party or under which IES or
    any  of the IES Subsidiaries  has obligations and, with  respect to each IES
    Benefit Plan, where applicable,
 
           (i) such plan and summary plan description,
 
           (ii) the most recent annual report filed with the IRS,
 
          (iii)  each  related  trust  agreement,  insurance  contract,  service
       provider  or investment management agreement (including all amendments to
       each such document),
 
          (iv) the most  recent determination  of the  IRS with  respect to  the
       qualified status of such IES Benefit Plan, and
 
           (v) the most recent actuarial report or valuation.
 
        (g)   PAYMENTS RESULTING  FROM MERGER.   Except as set  forth in SECTION
    5.10(g) of the IES Disclosure Schedule:
 
           (i) The consummation or announcement of any transaction  contemplated
       by  this Agreement will not  (either alone or upon  the occurrence of any
       additional or further acts or events) result in any
 
               (A) payment (whether of severance pay or otherwise) becoming  due
           from  IES or  any of the  IES Subsidiaries to  any officer, employee,
           former employee  or director  thereof  or to  the trustee  under  any
           "RABBI  TRUST" or similar  arrangement that would  not have been paid
           without regard to such consummation or announcement or
 
               (B) benefit  under  any IES  Benefit  Plan being  established  or
           becoming accelerated, vested or payable; and
 
           (ii) neither IES nor any of the IES Subsidiaries is a party to
 
               (A)  any management, employment, deferred compensation, severance
           (including any payment, right or  benefit resulting from a change  in
           control),  bonus  or other  contract for  personal services  with any
           officer, director or employee,
 
               (B) any consulting contract with any person who prior to entering
           into such contract was a director or officer of IES, or
 
               (C) any material  plan, agreement,  arrangement or  understanding
           similar to any of the foregoing.
 
        (h)   LABOR AGREEMENTS.   Except as set forth  in SECTION 5.10(h) of the
    IES Disclosure Schedule, as of the date  hereof, neither IES nor any of  the
    IES  Subsidiaries is a party to any collective bargaining agreement or other
    labor agreement with any  union or labor organization.  To the knowledge  of
    IES,  as  of  the date  hereof,  there  is no  current  union representation
    question involving employees of IES or any of the IES Subsidiaries, nor does
    IES know  of  any activity  or  proceeding  of any  labor  organization  (or
    representative  thereof) or employee  group to organize  any such employees.
    Except as disclosed in the IES SEC Reports filed prior to the date hereof or
    in SECTION 5.10(h) of the IES Disclosure Schedule,
 
           (i)  there  is   no  material  unfair   labor  practice,   employment
       discrimination  or  other  complaint  against  IES  or  any  of  the  IES
       Subsidiaries pending, or to the knowledge of IES, threatened,
 
                                      A-37
<PAGE>
           (ii) there is  no strike,  lockout or material  dispute, slowdown  or
       work stoppage pending, or to the knowledge of IES, threatened, against or
       involving IES or any of the IES Subsidiaries, and
 
          (iii)  there  is  no  material  proceeding,  claim,  suit,  action  or
       governmental  investigation  pending  or,   to  the  knowledge  of   IES,
       threatened,  in respect of which any director, officer, employee or agent
       of IES or  any of the  IES Subsidiaries is  or may be  entitled to  claim
       indemnification  from  IES  or  such  IES  Subsidiary  pursuant  to their
       respective Articles of Incorporation or By-laws.
 
    Section 5.11  ENVIRONMENTAL PROTECTION.  Except as set forth in SECTION 5.11
of the IES Disclosure Schedule or in the IES SEC Reports filed prior to the date
hereof:
 
        (a)  COMPLIANCE.
 
           (i) Each of IES and the IES Subsidiaries and IES Joint Ventures is in
       compliance with  all  applicable  Environmental Laws,  except  where  the
       failure  to be in compliance,  in the aggregate does  not, and insofar as
       reasonably can  be foreseen,  would  not, have  an IES  Material  Adverse
       Effect; and
 
           (ii)  neither  IES nor  any  of the  IES  Subsidiaries and  IES Joint
       Ventures has received any communication (written or oral) from any person
       or Governmental  Authority  that alleges  that  IES  or any  of  the  IES
       Subsidiaries  and  IES  Joint Ventures  is  not in  such  compliance with
       applicable Environmental Laws.
 
        (b)  ENVIRONMENTAL PERMITS.   Each of IES  and the IES Subsidiaries  has
    obtained  all Environmental Permits necessary  for the construction of their
    facilities and the conduct of their operations, as applicable, and all  such
    Environmental  Permits are in good standing  or, where applicable, a renewal
    application has been timely  filed and is pending  agency approval, and  IES
    and  the IES Subsidiaries are in compliance with all terms and conditions of
    the  Environmental  Permits,  except  where  the  failure  to  be  in   such
    compliance,  in the  aggregate does  not, and  insofar as  reasonably can be
    foreseen, would not, have an IES Material Adverse Effect.
 
        (c)  ENVIRONMENTAL  CLAIMS.   There is no  material Environmental  Claim
    pending
 
           (i) against IES or any of the IES Subsidiaries or IES Joint Ventures,
 
           (ii)   against  any  person   or  entity  whose   liability  for  any
       Environmental Claim IES or  any of the IES  Subsidiaries has or may  have
       retained or assumed either contractually or by operation of law, or
 
          (iii) against any real or personal property or operations which IES or
       any of the IES Subsidiaries owns, leases or manages, in whole or in part.
 
        (d)    RELEASES.   To  the knowledge  of IES,  there  have not  been any
    material Releases of any Hazardous Material that would be reasonably  likely
    to  form the basis of any material Environmental Claim against IES or any of
    the IES Subsidiaries, or  against any person or  entity whose liability  for
    any  material Environmental Claim IES or any  of the IES Subsidiaries has or
    may have retained or assumed either contractually or by operation of law.
 
        (e)   PREDECESSORS.   To  the  knowledge of  IES,  with respect  to  any
    predecessor  of IES  or any  of the IES  Subsidiaries, there  is no material
    Environmental Claim pending or threatened, and there has been no Release  of
    Hazardous Materials that would be reasonably likely to form the basis of any
    material Environmental Claim.
 
                                      A-38
<PAGE>
        (f)   DISCLOSURE.  To IES's knowledge,  IES has disclosed to each of WPL
    and Interstate all  material facts  which IES reasonably  believes form  the
    basis of a material Environmental Claim arising from
 
           (i) the cost of IES pollution control equipment currently required or
       known to be required in the future;
 
           (ii)  current IES remediation costs or IES remediation costs known to
       be required in the future; or
 
          (iii)  any  other  environmental  matter  affecting  IES  or  the  IES
       Subsidiaries or IES Joint Ventures.
 
    Section  5.12  REGULATION AS A UTILITY.   Utilities is regulated as a public
utility in the  State of  Iowa and in  no other  state. Except as  set forth  in
SECTION  5.12 of  the IES Disclosure  Schedule, neither IES  nor any "SUBSIDIARY
COMPANY" or "AFFILIATE" of IES is subject  to regulation as a public utility  or
public service company (or similar designation) by any other state in the United
States  or any foreign country.  IES is an exempt  holding company under SECTION
3(a)(1) of the 1935 Act.
 
    Section 5.13  VOTE REQUIRED.  The  approval by the holders of a majority  of
the  votes entitled  to be  cast by all  holders of  IES Common  Stock (the "IES
SHAREHOLDERS' APPROVAL") to  approve the  IES Merger, is  the only  vote of  the
holders  of any class or series of capital  stock of IES required for any of the
transactions required by this Agreement or the Stock Option Agreements to  which
IES is a party.
 
    Section  5.14  ACCOUNTING MATTERS.  Neither IES nor, to IES's knowledge, any
of its Affiliates has taken or agreed to take any action that would prevent  IES
from  accounting for the transactions to  be effected pursuant to this Agreement
as  a  pooling  of  interests  in  accordance  with  GAAP  and  applicable   SEC
regulations.
 
    Section  5.15    APPLICABILITY  OF  CERTAIN IOWA  LAW,  ETC.    Assuming the
representations and warranties of WPL and  Interstate made in SECTIONS 4.18  and
6.18,  respectively, are correct, none of the "FAIR PRICE" provisions of SECTION
502.214.7 of the IBCA, or any other takeover related provisions of the IBCA (or,
to the  knowledge of  IES, any  other  similar state  statute) or  the  Restated
Articles  of Incorporation  or By-laws of  IES is applicable  to the transaction
contemplated by  this  Agreement, including  the  granting or  exercise  of  the
IES/WPL  and  IES/Interstate Stock  Option Agreements  (except  as set  forth on
SCHEDULE 5.15 of the IES Disclosure Schedule).
 
    Section 5.16  OPINION OF FINANCIAL ADVISOR.  As of the date hereof, IES  has
received  the opinion  of Morgan Stanley  & Co. Incorporated  ("MORGAN"), to the
effect that, as  of the  date hereof,  the IES  Ratio, taking  into account  the
Interstate  Ratio, is fair from a financial point  of view to the holders of IES
Common Stock.
 
    Section 5.17  INSURANCE.   Except as  set forth in SECTION  5.17 of the  IES
Disclosure  Schedule, each  of IES  and the  IES Subsidiaries  is, and  has been
continuously  since  January  1,  1990,  insured  with  financially  responsible
insurers  in such amounts and against such  risks and losses as are customary in
all material respects for companies conducting the business conducted by IES and
the IES Subsidiaries  during such time  period. Except as  set forth in  SECTION
5.17 of the IES Disclosure Schedule, neither IES nor any of the IES Subsidiaries
has  received  any notice  of cancellation  or termination  with respect  to any
material insurance policy of IES or  any of the IES Subsidiaries. The  insurance
policies  of IES  and each  of the  IES Subsidiaries  are valid  and enforceable
policies in all material respects.
 
    Section 5.18  OWNERSHIP OF WPL AND  INTERSTATE COMMON STOCK.  Except as  set
forth in SECTION 5.18 of the IES Disclosure Schedule, and except pursuant to the
terms  of the WPL/IES Stock Option Agreement and the Interstate/IES Stock Option
Agreement, IES does not "BENEFICIALLY OWN" (as such term is defined for purposes
of SECTION  13(d)  of the  Exchange  Act) any  shares  of WPL  Common  Stock  or
Interstate Common Stock.
 
                                      A-39
<PAGE>
    Section  5.19    IES  RIGHTS  AGREEMENT.    Assuming  the  accuracy  of  the
representations contained in  SECTIONS 4.18  and 6.18, the  consummation of  the
transactions contemplated by this Agreement will not result in the triggering of
any  right or entitlement of IES  shareholders under the Rights Agreement, dated
as of November 6, 1991,  between IES and IES, as  rights agent (the "IES  RIGHTS
AGREEMENT").
 
    Section  5.20  OPERATIONS  OF NUCLEAR POWER  PLANT.  Except  as set forth in
SECTION 5.20 of the IES Disclosure Schedule, the operations of the Duane  Arnold
Energy   Center  ("DAEC")  owned  by  IES  (together  with  Central  Iowa  Power
Cooperative and Cornbelt Power Cooperative,  as tenants in common) and  operated
by  IES, have at all times been  conducted in compliance with applicable health,
safety, regulatory and other legal requirements, except where the failure to  be
in  compliance  in the  aggregate does  not,  and insofar  as can  reasonably be
foreseen, would  not,  have  an  IES Material  Adverse  Effect.  DAEC  maintains
emergency  plans  designed  to respond  to  an  unplanned release  from  DAEC of
radioactive  materials  into  the  environment.  Customary  liability  insurance
consistent  with industry practice  and consistent with IES's  view of the risks
inherent in the  operation of  a nuclear  power facility  currently exists  with
respect  to DAEC. Plans for  the decommissioning of DAEC  and for the short-term
storage of spent nuclear fuel conform  with the requirements of applicable  law,
and  such  plans  have  at  all  times  been  funded  consistently  with  budget
projections for such plans.
 
                                   ARTICLE VI
                  REPRESENTATIONS AND WARRANTIES OF INTERSTATE
 
    Interstate represents and warrants to WPL and IES as follows:
 
    Section 6.1  ORGANIZATION AND QUALIFICATION.  Except as set forth in SECTION
6.1 of  the Disclosure  Schedule to  this Agreement  prepared and  delivered  by
Interstate  (the "INTERSTATE DISCLOSURE  SCHEDULE"), each of  Interstate and the
Interstate  Subsidiaries  (as  hereinafter   defined)  is  a  corporation   duly
organized,  validly existing  and in  good standing  (to the  extent applicable)
under the laws of its respective jurisdiction of incorporation or  organization,
has all requisite corporate power and authority, and has been duly authorized by
all  necessary approvals  and orders  to own, lease  and operate  its assets and
properties to the extent owned, leased and operated and to carry on its business
as it is now being conducted and is duly qualified and in good standing (to  the
extent  applicable) to do business in  each respective jurisdiction in which the
nature of its business or the ownership or leasing of its assets and  properties
makes  such qualification necessary, other than  in such jurisdictions where the
failure to be so qualified and in  good standing would not, when taken  together
with  all other such failures,  have a material adverse  effect on the business,
operations, properties,  assets,  condition  (financial or  otherwise),  or  the
results  of operations of Interstate and  the Interstate Subsidiaries taken as a
whole or  on  the consummations  of  the transactions  contemplated  hereby  (an
"INTERSTATE MATERIAL ADVERSE EFFECT").
 
    Section 6.2  SUBSIDIARIES.
 
        (a)  SECTION  6.2 of  the Interstate  Disclosure  Schedule sets  forth a
    description as  of  the date  hereof,  of all  Interstate  Subsidiaries  and
    Interstate  Joint Ventures, including  (i) the name of  each such entity and
    Interstate's interest therein, and (ii) a brief description of the principal
    line or lines of business conducted by each such entity.
 
        (b) Except as  set forth  in SECTION  6.2 of  the Interstate  Disclosure
    Schedule, none of the Interstate Subsidiaries is a "PUBLIC UTILITY COMPANY,"
    a  "HOLDING COMPANY," A "SUBSIDIARY COMPANY" or an "AFFILIATE" of any public
    utility company within  the meaning of  SECTION 2(a)(5), 2(a)(7),  2(a)(8)OR
    2(a)(11) of the 1935 Act, respectively.
 
        (c)  Except as  set forth  in SECTION  6.2 of  the Interstate Disclosure
    Schedule, all of the issued and outstanding shares of capital stock of  each
    Interstate  Subsidiary  are  duly authorized,  validly  issued,  fully paid,
    nonassessable and  free of  preemptive rights,  and are  owned, directly  or
    indirectly, by Interstate free and clear of any liens, claims, encumbrances,
    security interests, equities,
 
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<PAGE>
    charges  and options of any nature  whatsoever, and there are no outstanding
    subscriptions, options, calls,  contracts, voting trusts,  proxies or  other
    commitments, understandings, restrictions, arrangements, rights or warrants,
    including  any  right  of  conversion  or  exchange  under  any  outstanding
    security, instrument  or other  agreement,  obligating any  such  Interstate
    Subsidiary  to issue, deliver or  sell, or cause to  be issued, delivered or
    sold, additional shares of its capital stock or granting to any person other
    than Interstate or any Interstate Subsidiary any right to participate in its
    dividends or earnings or  obligating it to grant,  extend or enter into  any
    such agreement or commitment.
 
        (d) As used in this Agreement,
 
           (i)  "INTERSTATE SUBSIDIARY" shall mean any Subsidiary of Interstate;
       and
 
           (ii) "INTERSTATE  JOINT  VENTURE" shall  mean  any Joint  Venture  of
       Interstate or any Interstate Subsidiary.
 
    Section 6.3  CAPITALIZATION.
 
        (a) The authorized capital stock of Interstate consists of
 
           (i)  30,000,000 shares of Interstate  Common Stock of which 9,564,287
       shares were issued and outstanding as of September 30, 1995,
 
           (ii) 2,000,000 shares of Interstate Preferred Stock were  authorized,
       of  which 761,381 shares of the  4.36% series, 4.68% series, 6.40% series
       and 7.76% series were  issued and outstanding as  of September 30,  1995,
       and
 
          (iii)  2,000,000  shares  of Interstate  Preference  Stock,  $1.00 par
       value, of which  none were  issued and  outstanding as  of September  30,
       1995.
 
        (b)  All of the issued and outstanding shares of Interstate Common Stock
    and Interstate  Preferred Stock  are, and  any shares  of Interstate  Common
    Stock  issued pursuant to the Interstate/WPL and Interstate/IES Stock Option
    Agreements  will   be,  duly   authorized,  validly   issued,  fully   paid,
    nonassessable and free of preemptive rights.
 
        (c)  Except as  set forth  in SECTION  6.3 of  the Interstate Disclosure
    Schedule, as of  the date  hereof, there are  no outstanding  subscriptions,
    options,  calls,  contracts, voting  trusts,  proxies or  other commitments,
    understandings, restrictions,  arrangements, rights  or warrants,  including
    any  right  of  conversion  or  exchange  under  any  outstanding  security,
    instrument  or  other  agreement,  obligating  Interstate  or  any  of   the
    Interstate  Subsidiaries to issue,  deliver or sell, or  cause to be issued,
    delivered or sold, additional shares of the capital stock of Interstate,  or
    obligating  Interstate to grant, extend or  enter into any such agreement or
    commitment, other  than under  the Interstate/WPL  and Interstate/IES  Stock
    Option Agreements.
 
    Section 6.4  AUTHORITY; NON-CONTRAVENTION; STATUTORY APPROVALS; COMPLIANCE.
 
        (a)    AUTHORITY.   Interstate  has  all requisite  corporate  power and
    authority  to  enter  into  this   Agreement  and  the  Interstate/WPL   and
    Interstate/IES  Stock  Option  Agreements, and,  subject  to  the applicable
    Interstate  Shareholders'  Approval   (as  hereinafter   defined)  and   the
    applicable Interstate Required Statutory Approvals (as hereinafter defined),
    to consummate the transactions contemplated hereby or thereby. The execution
    and  delivery of  this Agreement  and the  Interstate/WPL and Interstate/IES
    Stock  Option  Agreements  and  the   consummation  by  Interstate  of   the
    transactions  contemplated hereby and  thereby have been  duly authorized by
    all necessary  corporate  action  on  the part  of  Interstate,  subject  to
    obtaining  the applicable  Interstate Shareholders'  Approval. Each  of this
    Agreement and the Interstate/WPL and Interstate/IES Stock Option  Agreements
    has been duly and validly executed and delivered by Interstate and, assuming
    the  due authorization,  execution and  delivery hereof  and thereof  by the
    other signatories  hereto and  thereto, constitutes  the valid  and  binding
    obligation  of  Interstate enforceable  against  it in  accordance  with its
    terms,   except   as    may   be   limited    by   applicable    bankruptcy,
 
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<PAGE>
    insolvency,  reorganization or other similar  laws affecting the enforcement
    of  creditors'  rights  generally,  and  except  that  the  availability  of
    equitable  remedies, including specific  performance, may be  subject to the
    discretion of any court before which any proceeding therefor may be brought.
 
        (b)  NON-CONTRAVENTION.   Except as set forth  in SECTION 6.4(b) of  the
    Interstate Disclosure Schedule, the execution and delivery of this Agreement
    and  the  Interstate/WPL  and  Interstate/ IES  Stock  Option  Agreements by
    Interstate do not,  and the  consummation of  the transactions  contemplated
    hereby or thereby will not, result in a Violation pursuant to any provisions
    of:
 
           (i)  the  Articles  of Incorporation,  By-laws  or  similar governing
       documents  of  Interstate  or  any  of  the  Interstate  Subsidiaries  or
       Interstate Joint Ventures;
 
           (ii) subject to obtaining the Interstate Required Statutory Approvals
       and  the receipt of  the Interstate Shareholders'  Approval, any statute,
       law, ordinance, rule,  regulation, judgment,  decree, order,  injunction,
       writ,  permit  or license  of  any Governmental  Authority  applicable to
       Interstate or  any of  the Interstate  Subsidiaries or  Interstate  Joint
       Ventures or any of their respective properties or assets; or
 
          (iii)  subject  to obtaining  the  third-party consents  set  forth in
       SECTION 6.4(b)  of the  Interstate Disclosure  Schedule (the  "INTERSTATE
       REQUIRED  CONSENTS"), any material note,  bond, mortgage, indenture, deed
       of trust,  license, franchise,  permit,  concession, contract,  lease  or
       other instrument, obligation or agreement of any kind to which Interstate
       or any of the Interstate Subsidiaries or the Interstate Joint Ventures is
       a party or by which it or any of its properties or assets may be bound or
       affected,
 
    excluding  from the foregoing clauses (ii)  and (iii) such violations which,
    in the aggregate do  not, and insofar as  reasonably can be foreseen,  would
    not, have an Interstate Material Adverse Effect.
 
        (c)   STATUTORY APPROVALS.  No declaration, filing or registration with,
    or notice  to or  authorization, consent  or approval  of, any  Governmental
    Authority  is necessary for the execution  and delivery of this Agreement or
    the Interstate/WPL and Interstate/IES Stock Option Agreements by  Interstate
    or the consummation by Interstate of the transactions contemplated hereby or
    thereby,  except as described in SECTION 6.4(c) of the Interstate Disclosure
    Schedule (the "INTERSTATE REQUIRED STATUTORY APPROVALS", it being understood
    that references in  this Agreement to  "OBTAINING" such Interstate  Required
    Statutory   Approvals  shall  mean  making  such  declarations,  filings  or
    registrations; giving such notices; obtaining such authorizations,  consents
    or  approvals; and  having such waiting  periods expire as  are necessary to
    avoid a violation of law).
 
        (d)  COMPLIANCE.
 
           (i) Except as set  forth in SECTION 6.4(d),  SECTION 6.10 or  SECTION
       6.11  of  the  Interstate Disclosure  Schedule,  or as  disclosed  in the
       Interstate SEC Reports (as hereinafter  defined) filed prior to the  date
       hereof, neither Interstate nor any of the Interstate Subsidiaries nor, to
       the knowledge of Interstate, any Interstate Joint Venture is in violation
       of,  is under investigation with respect to any violation of, or has been
       given notice or  been charged with  any violation of,  any law,  statute,
       order,  rule,  regulation,  ordinance  or  judgment  (including,  without
       limitation, any applicable environmental law, ordinance or regulation) of
       any Governmental Authority, except for violations which, in the aggregate
       do not, and  insofar as reasonably  can be foreseen,  would not, have  an
       Interstate Material Adverse Effect.
 
           (ii)  Except as set forth in SECTION 6.4(d) or in SECTION 6.11 of the
       Interstate   Disclosure   Schedule,   Interstate   and   the   Interstate
       Subsidiaries  and Interstate Joint Ventures have all Permits necessary to
       conduct their businesses as presently conducted, except those the failure
       of which to obtain,  in the aggregate do  not, and insofar as  reasonably
       can be foreseen, would not, have an Interstate Material Adverse Effect.
 
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<PAGE>
          (iii)  Except  as  set  forth  in  SECTION  6.4(d)  of  the Interstate
       Disclosure Schedule, each of  Interstate and the Interstate  Subsidiaries
       and  Interstate Joint Ventures is not  in breach, violation or default in
       the performance or observance of any  term or provision of, and no  event
       has  occurred which, with lapse of time or action by a third party, could
       result in a default under,
 
               (A) its Articles of Incorporation or By-laws, or
 
               (B) any  contract,  commitment, agreement,  indenture,  mortgage,
           loan  agreement,  note,  lease,  bond,  license,  approval  or  other
           instrument to which it is a party or by which it is bound or to which
           any of its property  is subject, except  for breaches, violations  or
           defaults  which,  in the  aggregate  do not,  and  insofar as  can be
           reasonably foreseen, would not,  have an Interstate Material  Adverse
           Effect.
 
    Section 6.5  REPORTS AND FINANCIAL STATEMENTS.
 
        (a)  The filings  required to be  made by Interstate  and the Interstate
    Subsidiaries since January 1,  1992 under the  Securities Act, the  Exchange
    Act,  the Power  Act, and  applicable state  laws and  regulations have been
    filed with the  SEC, the  FERC, or  any appropriate  state public  utilities
    commission,  as the case  may be, including  all forms, statements, reports,
    agreements (oral or  written) and  all documents,  exhibits, amendments  and
    supplements  appertaining  thereto,  and complied,  as  of  their respective
    dates, in  all material  respects with  all applicable  requirements of  the
    appropriate statute and the rules and regulations thereunder.
 
        (b)  Interstate has made  available to WPL  and IES a  true and complete
    copy of each form, report,  schedule, registration statement and  definitive
    proxy  statement filed by Interstate with the  SEC since January 1, 1992 (as
    such documents  have  since  the  time  of  their  filing  been  amended  or
    supplemented,  the "INTERSTATE SEC REPORTS") and each other filing described
    in SECTION 6.5(A). As of their respective dates, the Interstate SEC  Reports
    did  not contain any untrue statement of a  material fact or omit to state a
    material fact  required  to be  stated  therein  or necessary  to  make  the
    statements  therein, in  light of  the circumstances  under which  they were
    made, not misleading.
 
        (c) The audited consolidated financial statements and unaudited  interim
    financial  statements of Interstate  included in the  Interstate SEC Reports
    (collectively, the "INTERSTATE FINANCIAL STATEMENTS") have been prepared  in
    accordance  with GAAP (except  as may be  indicated therein or  in the notes
    thereto and except with respect to unaudited statements as permitted by Form
    10-Q under the Exchange Act) and fairly present in all material respects the
    financial position of Interstate as of the dates thereof and the results  of
    its  operations and cash flows  for the periods then  ended, subject, in the
    case of the  unaudited interim  financial statements,  to normal,  recurring
    audit adjustments.
 
        (d)  True,  accurate and  complete copies  of  the Restated  Articles of
    Incorporation and By-laws of  Interstate, as in effect  on the date  hereof,
    are included (or incorporated by reference) in the Interstate SEC Reports.
 
    Section  6.6  ABSENCE OF CERTAIN CHANGES  OR EVENTS.  Except as disclosed in
the Interstate SEC Reports  filed prior to  the date hereof or  as set forth  in
SECTION  6.6 of  the Interstate  Disclosure Schedule,  since December  31, 1994,
Interstate and each of the Interstate Subsidiaries and Interstate Joint Ventures
have conducted their businesses only in the ordinary course of their  respective
businesses consistent with past practice and there has not been, and no facts or
conditions  exist (other  than facts or  conditions of  general applicability to
electric utility  companies in  the  region in  which  WPL, IES  and  Interstate
operate) which, in the aggregate have or, insofar as reasonably can be foreseen,
would have, an Interstate Material Adverse Effect.
 
                                      A-43
<PAGE>
    Section  6.7  LITIGATION.  Except as disclosed in the Interstate SEC Reports
filed prior to the date  hereof or as set forth  in SECTION 6.7, SECTION 6.9  or
SECTION 6.11 of the Interstate Disclosure Schedule,
 
        (a)  there are no  claims, suits, actions or  proceedings pending or, to
    the knowledge of Interstate, threatened, nor are there, to the knowledge  of
    Interstate,  any investigations  or reviews  pending or  threatened against,
    relating to or affecting  Interstate or any  of the Interstate  Subsidiaries
    and, to the knowledge of Interstate, the Interstate Joint Ventures;
 
        (b)  there have not  been any developments since  December 31, 1994 with
    respect   to   such   disclosed   claims,   suits,   actions,   proceedings,
    investigations or reviews; and
 
        (c) there are no judgments, decrees, injunctions, rules or orders of any
    court,  governmental  department,  commission,  agency,  instrumentality  or
    authority  or  any  arbitrator  applicable  to  Interstate  or  any  of  the
    Interstate  Subsidiaries and, to the knowledge of Interstate, the Interstate
    Joint Ventures,
 
which, when taken together with any other nondisclosures of matters described in
clauses (a), (b) and (c), have, or insofar as reasonably can be foreseen,  would
have, an Interstate Material Adverse Effect.
 
    Section 6.8  REGISTRATION STATEMENT AND PROXY STATEMENT.
 
        (a)  None of the information supplied or  to be supplied by or on behalf
    of Interstate for inclusion or incorporation by reference in
 
           (i) the Registration  Statement will,  at the  time the  Registration
       Statement  is filed  with the  SEC and at  the time  it becomes effective
       under the Securities Act, contain any untrue statement of a material fact
       or omit  to state  any material  fact required  to be  stated therein  or
       necessary to make the statements therein not misleading, and
 
           (ii) the Proxy Statement will, at the date mailed to shareholders and
       at  the times of  the meetings of  shareholders to be  held in connection
       with the Interstate Merger,  contain any untrue  statement of a  material
       fact  or omit to state any material fact required to be stated therein or
       necessary in  order to  make  the statements  therein,  in light  of  the
       circumstances under which they are made, not misleading.
 
        (b) The Registration Statement and the Proxy Statement will comply as to
    form  in all material respects with the provisions of the Securities Act and
    the Exchange Act,  respectively, and  the applicable  rules and  regulations
    thereunder.
 
    Section  6.9   TAX  MATTERS.   Except as  set  forth in  SECTION 6.9  of the
Interstate Disclosure Schedule:
 
        (a)   FILING  OF  TIMELY  TAX  RETURNS.   Interstate  and  each  of  the
    Interstate  Subsidiaries have filed (or there  has been filed on its behalf)
    all Tax Returns required to be filed  by each of them under applicable  law.
    All  such Tax Returns were  and are in all  material respects true, complete
    and correct and filed on a timely basis.
 
        (b)    PAYMENT  OF  TAXES.    Interstate  and  each  of  the  Interstate
    Subsidiaries have, within the time and in the manner prescribed by law, paid
    all  Taxes that are currently due and  payable except for those contested in
    good faith and for which adequate reserves have been taken.
 
        (c)   TAX RESERVES.   Interstate  and the  Interstate Subsidiaries  have
    established  on their books  and records reserves adequate  to pay all Taxes
    and reserves for deferred income taxes in accordance with GAAP.
 
        (d)  TAX LIENS.  There are no Tax liens upon the assets of Interstate or
    any of the Interstate Subsidiaries except liens for Taxes not yet due.
 
        (e)    WITHHOLDING  TAXES.    Interstate  and  each  of  the  Interstate
    Subsidiaries  have complied in all material  respects with the provisions of
    the Code relating to the withholding of Taxes, as
 
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<PAGE>
    well as similar provisions under any  other laws, and have, within the  time
    and  in the manner prescribed by law,  withheld from employee wages and paid
    over to the proper governmental authorities all amounts required.
 
        (f)  EXTENSIONS OF TIME FOR FILING TAX RETURNS.  Neither Interstate  nor
    any  of  the Interstate  Subsidiaries has  requested  any extension  of time
    within which to file  any Tax Return,  which Tax Return  has not since  been
    timely filed.
 
        (g)   WAIVERS OF STATUTE OF LIMITATIONS.   Neither Interstate nor any of
    the  Interstate  Subsidiaries  has  executed  any  outstanding  waivers   or
    comparable  consents regarding the application of the statute of limitations
    with respect to any Taxes or Tax Returns.
 
        (h)  EXPIRATION OF STATUTE OF  LIMITATIONS.  The statute of  limitations
    for  the assessment of all Taxes has  expired for all applicable Tax Returns
    of Interstate and each of the  Interstate Subsidiaries or those Tax  Returns
    have been examined by the appropriate taxing authorities for all Tax periods
    ended  before the  date hereof,  and no  deficiency for  any Taxes  has been
    proposed, asserted or assessed against  Interstate or any of the  Interstate
    Subsidiaries that has not been resolved and paid in full.
 
        (i)   AUDIT, ADMINISTRATIVE  AND COURT PROCEEDINGS.   No audits or other
    administrative proceedings or court  proceedings are presently pending  with
    regard  to any Taxes or  Tax Returns of Interstate  or any of the Interstate
    Subsidiaries.
 
        (j)  POWERS OF ATTORNEY.   No power of  attorney currently in force  has
    been  granted by Interstate or any of the Interstate Subsidiaries concerning
    any Tax matter.
 
        (k)   TAX  RULINGS.    Neither Interstate  nor  any  of  the  Interstate
    Subsidiaries  has received a Tax Ruling  or entered into a Closing Agreement
    with any taxing authority that would have a continuing adverse effect  after
    the Closing Date.
 
        (l)   AVAILABILITY OF TAX RETURNS.  Interstate has made available to WPL
    and IES complete and accurate copies  covering the six years ended  December
    31,  1994  of (i)  all Tax  Returns,  and any  amendments thereto,  filed by
    Interstate or any  of the  Interstate Subsidiaries, (ii)  all audit  reports
    received  from  any taxing  authority relating  to any  Tax Return  filed by
    Interstate or  any of  the Interstate  Subsidiaries, and  (iii) any  Closing
    Agreements  entered into by Interstate or any of the Interstate Subsidiaries
    with any taxing authority.
 
        (m)   TAX SHARING  AGREEMENTS.   Neither Interstate  nor any  Interstate
    Subsidiary  is a party to any agreement relating to allocating or sharing of
    Taxes.
 
        (n)  CODE SECTION  280G.  Neither Interstate  nor any of the  Interstate
    Subsidiaries  is a  party to  any agreement,  contract, or  arrangement that
    could  result,  on  account  of  the  transactions  contemplated  hereunder,
    separately  or in  the aggregate,  in the  payment of  any "EXCESS PARACHUTE
    PAYMENTS" within the meaning of SECTION 280G of the Code.
 
        (o)  LIABILITY FOR OTHERS.  None of Interstate or any of the  Interstate
    Subsidiaries has any liability for Taxes of any person other than Interstate
    and  the  Interstate  Subsidiaries (i)  under  Treasury  Regulations SECTION
    1.1502-6 (or any  similar provision  of state, local  or foreign  law) as  a
    transferee or successor, (ii) by contract, or (iii) otherwise.
 
    Section 6.10  EMPLOYEE MATTERS; ERISA.
 
        (a)    BENEFIT  PLANS.   SECTION  6.10(a) of  the  Interstate Disclosure
    Schedule contains a true  and complete list of  each employee benefit  plan,
    program  or arrangement covering employees, former employees or directors of
    Interstate and each of the  Interstate Subsidiaries or their  beneficiaries,
    or providing benefits to such persons in respect of services provided to any
    such  entity, including, but  not limited to,  employee benefit plans within
    the meaning of SECTION 3(3) of
 
                                      A-45
<PAGE>
    ERISA and any severance  or change in  control agreement (collectively,  the
    "INTERSTATE BENEFIT PLANS"). For the purposes of this SECTION 6.10 only, the
    term  "INTERSTATE"  shall  be deemed  to  include the  predecessors  of such
    company.
 
        (b)   CONTRIBUTIONS.   Except as  set forth  in SECTION  6.10(b) of  the
    Interstate   Disclosure  Schedule,  all  material  contributions  and  other
    payments required  to  be  made  by Interstate  or  any  of  the  Interstate
    Subsidiaries  to any Interstate  Benefit Plan (or to  any person pursuant to
    the terms  thereof)  have  been  made  or the  amount  of  such  payment  or
    contribution  obligation  has  been reflected  in  the  Interstate Financial
    Statements.
 
        (c)  QUALIFICATION; COMPLIANCE.  Except as set forth in SECTION  6.10(b)
    of  the Interstate Disclosure Schedule, each of the Interstate Benefit Plans
    intended to be "QUALIFIED" within the meaning of SECTION 401(a) of the  Code
    has  been determined by the IRS to be so qualified, and, to the knowledge of
    Interstate,  no  circumstances  exist   that  are  reasonably  expected   by
    Interstate to result in the revocation of any such determination. Interstate
    is  in compliance in all  respects with, and each  of the Interstate Benefit
    Plans is  and has  been operated  in all  respects in  compliance with,  all
    applicable  laws, rules and regulations governing each such plan, including,
    without limitation, ERISA and  the Code except for  any violations that,  in
    the  aggregate do not, and insofar as reasonably can be foreseen, would not,
    give rise to an Interstate Material Adverse Effect. Each Interstate  Benefit
    Plan intended to provide for the deferral of income, the reduction of salary
    or  other compensation, or to afford  other income tax benefits, complies in
    all material respects with the requirements of the applicable provisions  of
    the  Code  or other  laws, rules  and regulations  required to  provide such
    income tax benefits.
 
        (d)   LIABILITIES.    With  respect to  the  Interstate  Benefit  Plans,
    individually  and  in the  aggregate,  no event  has  occurred, and,  to the
    knowledge of Interstate, there  does not now exist  any condition or set  of
    circumstances  that  could  subject  Interstate  or  any  of  the Interstate
    Subsidiaries to any  liability arising under  the Code, ERISA  or any  other
    applicable  law (including,  without limitation,  any liability  of any kind
    whatsoever, whether direct or indirect, contingent, inchoate or otherwise to
    any such  plan or  the PBGC),  or  under any  indemnity agreement  to  which
    Interstate  is  subject,  which  liability,  excluding  liability  for  PBGC
    premiums, benefit claims  and funding  obligations payable  in the  ordinary
    course,  has,  or insofar  as  reasonably can  be  foreseen, would  have, an
    Interstate Material Adverse Effect.
 
        (e)  WELFARE  PLANS.   Except as  set forth  in SECTION  6.10(e) of  the
    Interstate  Disclosure Schedule, none  of the Interstate  Benefit Plans that
    are "WELFARE PLANS" within the meaning of SECTION 3(1) of ERISA provides for
    any benefits  payable to  or on  behalf of  any employee  or director  after
    termination  of  employment  or service,  as  the  case may  be,  other than
    elective continuation coverage required to  be provided under SECTION  4980B
    of  the Code or Part 6 of Title I  of ERISA or coverage which expires at the
    end of the calendar month following such event.
 
        (f)  DOCUMENTS MADE AVAILABLE.  Interstate has made available to WPL and
    IES a true and correct copy of each collective bargaining agreement to which
    Interstate or any of the Interstate  Subsidiaries is a party or under  which
    Interstate  or any of the Interstate  Subsidiaries has obligations and, with
    respect to each Interstate Benefit Plan, where applicable,
 
           (i) such plan and summary plan description,
 
           (ii) the most recent annual report filed with the IRS,
 
          (iii)  each  related  trust  agreement,  insurance  contract,  service
       provider  or investment management agreement (including all amendments to
       each such document),
 
          (iv) the most  recent determination  of the  IRS with  respect to  the
       qualified status of such Interstate Benefit Plan, and
 
           (v) the most recent actuarial report or valuation.
 
                                      A-46
<PAGE>
        (g)   PAYMENTS RESULTING  FROM MERGER.   Except as set  forth in SECTION
    6.10(g) of the Interstate Disclosure Schedule:
 
           (i) The consummation or announcement of any transaction  contemplated
       by  this Agreement will not  (either alone or upon  the occurrence of any
       additional or further acts or events) result in any
 
               (A) payment (whether of severance pay or otherwise) becoming  due
           from Interstate or any of the Interstate Subsidiaries to any officer,
           employee, former employee or director thereof or to the trustee under
           any  "RABBI TRUST"  or similar arrangement  that would  not have been
           paid without regard to such consummation or announcement, or
 
               (B) benefit under any  Interstate Benefit Plan being  established
           or becoming accelerated, vested or payable; and
 
           (ii)  neither Interstate nor any of  the Interstate Subsidiaries is a
       party to
 
               (A) any management, employment, deferred compensation,  severance
           (including  any payment, right or benefit  resulting from a change in
           control), bonus  or other  contract for  personal services  with  any
           officer, director or employee,
 
               (B) any consulting contract with any person who prior to entering
           into such contract was a director or officer of Interstate, or
 
               (C)  any material  plan, agreement,  arrangement or understanding
           similar to any of the foregoing.
 
        (h)  LABOR AGREEMENTS.   Except as set forth  in SECTION 6.10(h) of  the
    Interstate  Disclosure Schedule, as  of the date  hereof, neither Interstate
    nor any  of  the  Interstate  Subsidiaries is  a  party  to  any  collective
    bargaining  agreement  or  other labor  agreement  with any  union  or labor
    organization. To the knowledge of Interstate,  as of the date hereof,  there
    is   no  current  union  representation   question  involving  employees  of
    Interstate or any of the  Interstate Subsidiaries, nor does Interstate  know
    of  any activity or proceeding of  any labor organization (or representative
    thereof) or  employee  group  to  organize any  such  employees.  Except  as
    disclosed in the Interstate SEC Reports filed prior to the date hereof or in
    SECTION 6.10(h) of the Interstate Disclosure Schedule,
 
           (i)   there  is   no  material  unfair   labor  practice,  employment
       discrimination or  other  complaint  against Interstate  or  any  of  the
       Interstate  Subsidiaries  pending,  or to  the  knowledge  of Interstate,
       threatened,
 
           (ii) there is  no strike,  lockout or material  dispute, slowdown  or
       work  stoppage  pending, or  to the  knowledge of  Interstate threatened,
       against or involving  Interstate or any  of the Interstate  Subsidiaries,
       and
 
          (iii)  there  is  no  material  proceeding,  claim,  suit,  action  or
       governmental investigation pending  or, to the  knowledge of  Interstate,
       threatened,  in respect of which any director, officer, employee or agent
       of Interstate or any of the Interstate Subsidiaries is or may be entitled
       to claim indemnification  from Interstate or  such Interstate  Subsidiary
       pursuant to their respective Articles of Incorporation or by-laws.
 
    Section 6.11  ENVIRONMENTAL PROTECTION.  Except as set forth in SECTION 6.11
of  the Interstate  Disclosure Schedule or  in the Interstate  SEC Reports filed
prior to the date hereof:
 
        (a)  COMPLIANCE.
 
           (i) Each of Interstate and the Interstate Subsidiaries and Interstate
       Joint Ventures is in compliance  with all applicable Environmental  Laws,
       except  where the failure to be in compliance, in the aggregate does not,
       and insofar as reasonably can be foreseen, would not, have an  Interstate
       Material Adverse Effect; and
 
                                      A-47
<PAGE>
           (ii)  neither Interstate nor  any of the  Interstate Subsidiaries and
       Interstate Joint  Ventures has  received  any communication  (written  or
       oral)  from  any  person  or  Governmental  Authority  that  alleges that
       Interstate or any  of the  Interstate Subsidiaries  and Interstate  Joint
       Ventures  is not  in compliance,  as required  by clause  (i) above, with
       applicable Environmental Laws.
 
        (b)   ENVIRONMENTAL PERMITS.    Each of  Interstate and  the  Interstate
    Subsidiaries  has  obtained  all  Environmental  Permits  necessary  for the
    construction of their  facilities and  the conduct of  their operations,  as
    applicable,  and all  such Environmental  Permits are  in good  standing or,
    where applicable, a renewal application has been timely filed and is pending
    agency approval,  and  Interstate and  the  Interstate Subsidiaries  are  in
    compliance  with  all terms  and  conditions of  the  Environmental Permits,
    except where the  failure to be  in such compliance,  in the aggregate  does
    not,  and  insofar  as  reasonably  can  be  foreseen,  would  not,  have an
    Interstate Material Adverse Effect.
 
        (c)  ENVIRONMENTAL  CLAIMS.   There is no  material Environmental  Claim
    pending
 
           (i)  against  Interstate or  any  of the  Interstate  Subsidiaries or
       Interstate Joint Ventures,
 
           (ii)  against  any   person  or  entity   whose  liability  for   any
       Environmental  Claim Interstate or any of the Interstate Subsidiaries has
       or may have retained or assumed  either contractually or by operation  of
       law, or
 
          (iii)  against  any  real  or personal  property  or  operations which
       Interstate or any of the Interstate Subsidiaries owns, leases or manages,
       in whole or in part.
 
        (d)  RELEASES.  To the knowledge  of Interstate, there has not been  any
    material  Releases of any Hazardous Material that would be reasonably likely
    to form the basis of any material Environmental Claim against Interstate  or
    any  of the Interstate  Subsidiaries, or against any  person or entity whose
    liability for  any material  Environmental Claim  Interstate or  any of  the
    Interstate   Subsidiaries  has  or  may  have  retained  or  assumed  either
    contractually or by operation of law.
 
        (e)  PREDECESSORS.  To the knowledge of Interstate, with respect to  any
    predecessor of Interstate or any of the Interstate Subsidiaries, there is no
    material  Environmental Claim pending  or threatened, and  there has been no
    Release of Hazardous Materials that would  be reasonably likely to form  the
    basis of any material Environmental Claim.
 
        (f)  DISCLOSURE.  To Interstate's knowledge, Interstate has disclosed to
    each  of WPL and IES all material facts which Interstate reasonably believes
    form the basis of a material Environmental Claim arising from
 
           (i) the  cost of  Interstate  pollution control  equipment  currently
       required or known to be required in the future;
 
           (ii)  current Interstate remediation  costs or Interstate remediation
       costs known to be required in the future; or
 
          (iii) any  other  environmental  matter affecting  Interstate  or  the
       Interstate Subsidiaries or Interstate Joint Ventures.
 
    Section  6.12  REGULATION AS A UTILITY.  Interstate is regulated as a public
utility in the States  of Iowa, Illinois  and Minnesota and  in no other  state.
Except  as set forth in  SECTION 6.12 of the  Interstate Disclosure Schedule, no
"SUBSIDIARY COMPANY" or "AFFILIATE" of Interstate is subject to regulation as  a
public  utility or public service company  (or similar designation) by any other
state in the United States or any foreign country.
 
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<PAGE>
    Section 6.13  VOTE REQUIRED.  The  approval by the holders of a majority  of
the outstanding shares of Interstate Common Stock (the "INTERSTATE SHAREHOLDERS'
APPROVAL")  to approve the Interstate Merger is  the only vote of the holders of
any class or  series of  capital stock  of Interstate  required for  any of  the
transactions  required by this Agreement or the Stock Option Agreements to which
Interstate is  a party.  The approval  by the  holders of  shares of  Interstate
Preferred Stock is not required to approve the Interstate Merger.
 
    Section  6.14  ACCOUNTING MATTERS.   Neither Interstate nor, to Interstate's
knowledge, any of its  Affiliates has taken  or agreed to  take any action  that
would  prevent Interstate  from accounting for  the transactions  to be effected
pursuant to this Agreement as a pooling of interests in accordance with GAAP and
applicable SEC regulations.
 
    Section 6.15   APPLICABILITY OF  CERTAIN DELAWARE  LAW, ETC.   Assuming  the
representations  and warranties of WPL  and IES made in  SECTIONS 4.18 and 5.18,
respectively, are correct, none of the provisions of SECTION 203 of the DGCL, or
any other  takeover related  provisions of  the  DGCL (or  to the  knowledge  of
Interstate,  any  other  similar  State statute)  or  the  Restated  Articles of
Incorporation or  By-laws  of  Interstate are  applicable  to  the  transactions
contemplated  by  this  Agreement, including  the  granting or  exercise  of the
Interstate/WPL and Interstate/IES Stock Option  Agreements (except as set  forth
in SECTION 6.15 of the Interstate Disclosure Schedule).
 
    Section  6.16   OPINION OF FINANCIAL  ADVISOR.  Interstate  has received the
opinion of Salomon  Brothers Inc  ("SALOMON") dated  November 10,  1995, to  the
effect  that, as of  the date thereof,  the consideration to  be received by the
holders of  Interstate Common  Stock in  the Interstate  Merger is  fair from  a
financial point of view to the holders of Interstate Common Stock.
 
    Section  6.17   INSURANCE.    Except as  set forth  in  SECTION 6.17  of the
Interstate  Disclosure  Schedule,   each  of  Interstate   and  the   Interstate
Subsidiaries  is, and has been continuously  since January 1, 1990, insured with
financially responsible  insurers in  such amounts  and against  such risks  and
losses  as are customary  in all material respects  for companies conducting the
business conducted by  Interstate and  the Interstate  Subsidiaries during  such
time  period. Except as set  forth in SECTION 6.17  of the Interstate Disclosure
Schedule, neither Interstate nor any of the Interstate Subsidiaries has received
any notice of cancellation or termination with respect to any material insurance
policy of  Interstate  or any  of  the Interstate  Subsidiaries.  The  insurance
policies  of Interstate  and each of  the Interstate Subsidiaries  are valid and
enforceable policies in all material respects.
 
    Section 6.18  OWNERSHIP OF WPL AND IES COMMON STOCK.  Except pursuant to the
terms  of  the  WPL/Interstate  and  IES/Interstate  Stock  Option   Agreements,
Interstate  does not "BENEFICIALLY OWN" (as such term is defined for purposes of
SECTION 13(d) of the Exchange Act) any shares of WPL Common Stock or IES  Common
Stock.
 
                                  ARTICLE VII
                     CONDUCT OF BUSINESS PENDING THE MERGER
 
    Section  7.1  COVENANTS OF THE PARTIES.   After the date hereof and prior to
the Effective  Time or  earlier  termination of  this  Agreement, WPL,  IES  and
Interstate each agree as set forth in this Article VII, each as to itself and to
each   of  the  WPL  Subsidiaries,  the  IES  Subsidiaries  and  the  Interstate
Subsidiaries, respectively,  except as  expressly contemplated  or permitted  in
this  Agreement, the Stock Option Agreements, or to the extent the other parties
hereto shall otherwise consent in writing.
 
    Section 7.2   ORDINARY COURSE  OF BUSINESS.   Each party  hereto shall,  and
shall  cause its  Subsidiaries to, carry  on their respective  businesses in the
usual,  regular  and  ordinary  course  in  substantially  the  same  manner  as
heretofore  conducted and  use all  commercially reasonable  efforts to preserve
intact their present business organizations and goodwill, preserve the  goodwill
and  relationships with customers, suppliers and others having business dealings
with them and,  subject to  prudent management  of workforce  needs and  ongoing
programs   currently   in  force,   keep   available  the   services   of  their
 
                                      A-49
<PAGE>
present officers and employees. Except  as set forth in  SECTION 7.2 of the  WPL
Disclosure  Schedule, the IES  Disclosure Schedule or  the Interstate Disclosure
Schedule, respectively, no party  shall, nor shall any  party permit any of  its
Subsidiaries  to, enter into a  new line of business, or  make any change in the
line of business  it engages in  as of  the date hereof  involving any  material
investment of assets or resources or any material exposure to liability or loss,
in the case of WPL, to WPL and its Subsidiaries taken as a whole, in the case of
IES,  to  IES  and  its Subsidiaries  taken  as  a  whole, and  in  the  case of
Interstate, to Interstate and its Subsidiaries taken as a whole.
 
    Section 7.3  DIVIDENDS.  No party  shall, nor shall any party permit any  of
its Subsidiaries to,
 
        (a)  (i)  declare or pay any dividends on or make other distributions in
    respect of any of their capital stock other than
 
           (A) to such party or its wholly-owned Subsidiaries,
 
           (B) dividends  required  to  be  paid on  any  IES  Preferred  Stock,
       Utilities  Preferred Stock, WP&LC Preferred Stock or Interstate Preferred
       Stock in accordance with the respective terms thereof, and
 
           (C) regular quarterly  dividends on IES  Common Stock and  Interstate
       Common  Stock, with  usual record  and payment  dates, during  any fiscal
       year, which dividends shall not exceed 100% of the prior year in the case
       of IES and 100% of the prior year in the case of Interstate, and
 
           (D) regular  quarterly  dividends on  WPL  Common Stock,  with  usual
       record  and payment dates, during any  fiscal year, which dividends shall
       not exceed 105% of the dividends for the prior fiscal year; and
 
        (ii) split, combine or reclassify any of their capital stock or issue or
    authorize or propose the issuance of any other securities in respect of,  in
    lieu of, or in substitution for, shares of their capital stock; or
 
       (iii) redeem, repurchase or otherwise acquire any shares of their capital
    stock, other than
 
           (A) redemptions, purchases or acquisitions required by the respective
       terms  of any series  of IES Preferred  Stock, Utilities Preferred Stock,
       WP&LC Preferred Stock, or Interstate Preferred Stock,
 
           (B) in connection  with refunding of  IES Preferred Stock,  Utilities
       Preferred Stock, WP&LC Preferred Stock or Interstate Preferred Stock with
       preferred  stock or debt at a lower  cost of funds (calculating such cost
       on an after-tax basis),
 
           (C) in connection with intercompany purchases of capital stock,
 
           (D) for the purpose of  funding employee stock ownership or  dividend
       reinvestment  and stock purchase plans  in accordance with past practice,
       or
 
           (E) as  set  forth  on  SECTION 7.3(a)(iii)  of  the  WPL  Disclosure
       Schedule, IES Disclosure Schedule or Interstate Disclosure Schedule.
 
        (b)  Each of WPL, IES,  and Interstate shall declare  a dividend on each
    share of its  Common Stock to  holders of record  of such shares  as of  the
    close  of business on the business day  next preceding the Effective Time in
    an amount equal to the product of
 
           (i) a fraction,
 
               (A) the numerator of which equals the number of days between  the
           payment date with respect to the most recent regular dividend paid by
           WPL,  IES, or Interstate, as the case may be, and the Effective Time,
           and
 
               (B) the denominator of which equals 91, and
 
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<PAGE>
           (ii) the amount of  the regular cash dividend  most recently paid  by
       WPL, IES or Interstate, as the case may be;
 
    PROVIDED,  HOWEVER, that if  any one or  more of WPL,  IES or Interstate has
    declared a regular quarterly dividend on  shares of its Common Stock with  a
    payment date (the "PAYMENT DATE") after the Effective Time, then no dividend
    as  provided  for in  this SECTION  7.3(b)  shall be  declared or  paid with
    respect to such shares and the dividend of the other party or parties  shall
    be  calculated by substituting "Payment Date" for "Effective Time" in clause
    (i)(A) of this SECTION 7.3(b).
 
        (c) Notwithstanding the foregoing,
 
           (i) WPL may redeem all or any portion of the WP&LC Preferred Stock if
       the Board of  Directors of WPL  in good faith  determines such course  of
       action will facilitate the transactions contemplated hereby,
 
           (ii)  IES may redeem all or any portion of the IES Preferred Stock or
       Utilities Preferred Stock  if the IES  Board of Directors  in good  faith
       determines  such  course  of  action  will  facilitate  the  transactions
       contemplated hereby, and
 
          (iii) Interstate  may redeem  all  or any  portion of  the  Interstate
       Preferred  Stock,  if the  Interstate Board  of  Directors in  good faith
       determines  such  course  of  action  will  facilitate  the  transactions
       contemplated hereby.
 
    Section 7.4  ISSUANCE OF SECURITIES.
 
        (a)  No party shall, nor shall any  party permit any of its Subsidiaries
    to, issue,  agree to  issue, deliver,  sell, award,  pledge, dispose  of  or
    otherwise  encumber or  authorize or  propose the  issuance, delivery, sale,
    award, pledge, disposal or other encumbrance of, any shares of their capital
    stock of any class or any  securities convertible into or exchangeable  for,
    or  any  rights,  warrants  or  options  to  acquire,  any  such  shares  or
    convertible or exchangeable securities, other than (w) pursuant to the Stock
    Option Agreements, (x)  pursuant to the  Benefit Plans relating  to the  WPL
    Subsidiaries  listed in (and in amounts no  greater than those set forth in)
    Section 7.4 of the WPL Disclosure Schedule, (y) issuances by a Subsidiary of
    a party  hereto to  the  party that  directly  or indirectly  controls  such
    Subsidiary or to a wholly-owned Subsidiary of such party, and (z) issuances:
 
           (i) in the case of IES and the IES Subsidiaries
 
               (A) in connection with refunding IES Preferred Stock or Utilities
           Preferred Stock with preferred stock or debt at a lower cost of funds
           (calculating such cost on an after-tax basis); and
 
               (B)  up to 450,000  shares of IES  Common Stock to  be issued for
           general corporate purposes,  including issuances  in connection  with
           acquisitions and financing and issuances pursuant to employee benefit
           plans, stock option and other incentive compensation plans, directors
           plans and stock purchase plans;
 
               (C)  issuances  of  IES  Common Stock  pursuant  to  IES dividend
           reinvestment plans; and
 
               (D) issuances of securities pursuant to the IES Rights Agreement.
 
           (ii) in the case of WPL and the WPL Subsidiaries
 
               (A) in connection  with refunding of  WP&LC Preferred Stock  with
           preferred  stock or debt  at a lower cost  of funds (calculating such
           cost on an after-tax basis); and
 
                                      A-51
<PAGE>
               (B) up to 1 million shares of  WPL Common Stock to be issued  for
           general  corporate purposes,  including issuances  in connection with
           acquisitions and financing and issuances pursuant to employee benefit
           plans, stock option and other incentive compensation plans, directors
           plans and stock purchase plans;
 
               (C) issuances  of  WPL  Common Stock  pursuant  to  WPL  dividend
           reinvestment plans; and
 
               (D) issuances of securities pursuant to the WPL Rights Agreement.
 
          (iii) in the case of Interstate and the Interstate Subsidiaries
 
               (A)  in connection  with refunding of  Interstate Preferred Stock
           with preferred stock or  debt at a lower  cost of funds  (calculating
           such cost on an after-tax basis); and
 
               (B)  up to 200,000 shares of Interstate Common Stock to be issued
           for general  corporate purposes,  including issuances  in  connection
           with  acquisitions and  financing and issuances  pursuant to employee
           benefit plans, stock option  and other incentive compensation  plans,
           directors plans and stock purchase plans; and
 
               (C) issuances of Interstate Common Stock pursuant to Interstate's
           dividend reinvestment plans.
 
        (b) The parties shall promptly furnish to each other such information as
    may  be reasonably requested  including financial information  and take such
    action as may  be reasonably  necessary and otherwise  fully cooperate  with
    each  other  in  the preparation  of  any registration  statement  under the
    Securities Act and other documents necessary in connection with issuance  of
    securities  as  contemplated  by  this  SECTION  7.4,  subject  to obtaining
    customary indemnities.
 
    Section 7.5  CHARTER DOCUMENTS.  Except  as set forth in SECTION 7.5 of  the
WPL   Disclosure  Schedule,  the  IES  Disclosure  Schedule  or  the  Interstate
Disclosure Schedule,  except as  contemplated herein,  no party  shall amend  or
propose   to  amend  its  respective   articles  of  incorporation,  by-laws  or
regulations, or similar organic documents.
 
    Section 7.6  NO ACQUISITIONS.  Except as set forth in SECTION 7.6 of the WPL
Disclosure Schedule, the  IES Disclosure Schedule  or the Interstate  Disclosure
Schedule,  other than acquisitions by a party and its Subsidiaries not in excess
of $10 million in the case of WPL, $10 million in the case of IES and $5 million
in the case of Interstate, over the amount budgeted or forecasted by each  party
for  acquisition  expenditures, as  set forth  in  such SECTION  7.6 of  the WPL
Disclosure Schedule, the  IES Disclosure Schedule  or the Interstate  Disclosure
Schedule,  singularly or in the  aggregate, no party shall,  nor shall any party
permit any of its Subsidiaries to,  acquire, or publicly propose to acquire,  or
agree  to acquire, by merger or consolidation with, or by purchase or otherwise,
a substantial equity interest in or a substantial portion of the assets of,  any
business   or  any  corporation,  partnership,  association  or  other  business
organization or  division thereof,  nor  shall any  party  acquire or  agree  to
acquire  a  material amount  of  assets other  than  in the  ordinary  course of
business consistent with past practice.
 
    Section 7.7  CAPITAL  EXPENDITURES AND EMISSION ALLOWANCES.   Except as  set
forth in SECTION 7.7 of the WPL Disclosure Schedule, the IES Disclosure Schedule
or  the Interstate Disclosure Schedule,  or as required by  law, no party shall,
nor shall  any  party  permit any  of  its  Subsidiaries to,  (i)  make  capital
expenditures  in excess of  $50 million in the  case of WPL,  $80 million in the
case of IES, and $16 million in the case of Interstate over the amount  budgeted
by  each such party for capital expenditures as set forth in such SECTION 7.7 of
the WPL  Disclosure Schedule,  the  IES Disclosure  Schedule or  the  Interstate
Disclosure  Schedule, or (ii) enter into written commitments for the purchase of
sulfur dioxide  emission  allowances  as  provided for  by  the  Clean  Air  Act
Amendments  of 1990, in excess (singularly or in the aggregate) of $1 million in
the case of  WPL, $500,000  in the  case of  IES, and  $250,000 in  the case  of
Interstate.
 
                                      A-52
<PAGE>
    Section  7.8  NO DISPOSITIONS.  Except as set forth in SECTION 7.8of the WPL
Disclosure Schedule, the  IES Disclosure Schedule  or the Interstate  Disclosure
Schedule,  other than  dispositions by  a party  and its  Subsidiaries of assets
having a fair market  value (singularly or  in the aggregate)  of less than  $10
million  in the case of WPL,  $10 million in the case  of IES, and $2 million in
the case of Interstate, no  party shall, nor shall any  party permit any of  its
Subsidiaries  to, sell, lease, license, encumber or otherwise dispose of, any of
its assets, other than  encumbrances or dispositions in  the ordinary course  of
its business consistent with past practice.
 
    Section  7.9   INDEBTEDNESS.  Except  as contemplated by  this Agreement, no
party shall, nor shall  any party permit  any of its  Subsidiaries to, incur  or
guarantee  any  indebtedness  (including  any  debt  borrowed  or  guaranteed or
otherwise assumed including, without limitation, the issuance of debt securities
or warrants or rights to  acquire debt) or enter into  any "KEEP WELL" or  other
agreement  to maintain any  financial condition of another  person or enter into
any arrangement having the  economic effect of any  of the foregoing other  than
(i)  short-term indebtedness in the ordinary  course of business consistent with
past practice (such as the issuance of  commercial paper or the use of  existing
credit  facilities); (ii) long-term  indebtedness not aggregating  more than $40
million in the case of WPL, $60 million  in the case of IES, and $20 million  in
the   case  of  Interstate;  (iii)  arrangements  between  such  party  and  its
Subsidiaries or among its Subsidiaries; (iv) as set forth in SECTION 7.9 of  the
WPL   Disclosure  Schedule,  the  IES  Disclosure  Schedule  or  the  Interstate
Disclosure  Schedule;  (v)  in  connection   with  the  refunding  of   existing
indebtedness  at a lower cost of funds; or (vi) in connection with the refunding
of IES  Preferred Stock,  Utilities Preferred  Stock, WP&LC  Preferred Stock  or
Interstate Preferred Stock, as permitted in SECTION 7.3.
 
    Section  7.10  COMPENSATION, BENEFITS.  Except  as set forth in SECTION 7.10
of the WPL Disclosure  Schedule, the IES Disclosure  Schedule or the  Interstate
Disclosure  Schedule, as may be required by applicable law or as contemplated by
this Agreement,  no  party  shall,  nor  shall  any  party  permit  any  of  its
Subsidiaries to
 
        (a)  enter into, adopt or amend or increase the amount or accelerate the
    payment or vesting  of any  benefit or  amount payable  under, any  employee
    benefit  plan or other contract, agreement, commitment, arrangement, plan or
    policy maintained by, contributed to or entered into by such party or any of
    its Subsidiaries,  or  increase,  or enter  into  any  contract,  agreement,
    commitment  or arrangement  to increase in  any manner,  the compensation or
    fringe benefits, or otherwise to  extend, expand or enhance the  engagement,
    employment or any related rights, of any director, officer or other employee
    of such party or any of its Subsidiaries, except for normal increases in the
    ordinary  course  of business  consistent with  past  practice that,  in the
    aggregate, do not result in a material increase in benefits or  compensation
    expense to such party or any of its Subsidiaries, or
 
        (b)  enter  into  or  amend any  employment,  severance  or  special pay
    arrangement with respect to the  termination of employment or other  similar
    contract,  agreement or  arrangement with any  director or  officer or other
    employee, except  as  set  forth  in SECTION  7.10  of  the  WPL  Disclosure
    Schedule,  the IES Disclosure Schedule or the Interstate Disclosure Schedule
    or otherwise  in  the  ordinary  course of  business  consistent  with  past
    practice.
 
    Section  7.11  1935  ACT.  Except  as set forth  in SECTION 7.11  of the WPL
Disclosure Schedule, the  IES Disclosure Schedule  or the Interstate  Disclosure
Schedule, no party shall, nor shall any party permit any of its Subsidiaries to,
except  as required or contemplated by  this Agreement, engage in any activities
which would cause a change in its status, or that of its Subsidiaries, under the
1935 Act, or that would impair the ability of WPL to claim an exemption pursuant
to its order  under SECTION 3(a)(1)  of the 1935  Act or that  would impair  the
ability of IES to claim an exemption pursuant to its order under SECTION 3(a)(1)
of  the 1935 Act prior to the Effective  Time, other than (i) the application to
the SEC under the 1935  Act contemplated by this  Agreement for approval to  the
extent   required  of  the   transactions  contemplated  hereby   and  (ii)  the
registration of the Company pursuant to the 1935 Act.
 
                                      A-53
<PAGE>
    Section 7.12   TRANSMISSION,  GENERATION.   Except as  required pursuant  to
tariffs  on file with the FERC as of  the date hereof, in the ordinary course of
business consistent with past practice, or as  set forth in SECTION 7.12 of  the
WPL   Disclosure  Schedule,  the  IES  Disclosure  Schedule  or  the  Interstate
Disclosure Schedule,  no party  shall, nor  shall any  party permit  any of  its
Subsidiaries to,
 
        (a)  commence construction of any additional generating, transmission or
    delivery capacity, or
 
        (b) obligate itself  to purchase  or otherwise  acquire, or  to sell  or
    otherwise  dispose of, or to  share, any additional generating, transmission
    or delivery capacity,
 
in an amount in  excess of $30 million  in the case of  WPL, $80 million in  the
case  of IES, and $16 million in the  case of Interstate, except as set forth in
the budgets or forecasts of WPL dated  November 10, 1995, IES dated October  16,
1995  and Interstate  dated February  27, 1995,  respectively, which  budgets or
forecasts have been shared with each other party hereto.
 
    Section 7.13  ACCOUNTING.   Except as set forth in  SECTION 7.13 of the  WPL
Disclosure  Schedule, the IES  Disclosure Schedule or  the Interstate Disclosure
Schedule, no party shall, nor shall any party permit any of its Subsidiaries to,
make any changes in their accounting  methods, except as required by law,  rule,
regulation or GAAP.
 
    Section  7.14  POOLING.   No party shall, nor shall  any party permit any of
its Subsidiaries or, within the exercise of its best efforts, its Joint Ventures
to, take any action which would, or  would be reasonably likely to, prevent  the
Company  from accounting  for the transactions  to be effected  pursuant to this
Agreement as a pooling of interests  in accordance with GAAP and applicable  SEC
regulations,  and each party hereto shall  use all reasonable efforts to achieve
such result (including taking such actions as may be necessary to cure any facts
or circumstances  that  could  prevent such  transactions  from  qualifying  for
pooling-of-interests accounting treatment).
 
    Section  7.15  TAX-FREE STATUS.  No  party shall, nor shall any party permit
any of its Subsidiaries or, within the  exercise of its best efforts, its  Joint
Ventures  to, take any  actions which would,  or would be  reasonably likely to,
adversely affect the status of the  Merger as a tax-free transaction (except  as
to  dissenters' rights and fractional shares)  under SECTION 368(a) of the Code,
and each party hereto shall use all reasonable efforts to achieve such result.
 
    Section 7.16  AFFILIATE TRANSACTIONS.   Except as set forth in SECTION  7.16
of  the WPL Disclosure  Schedule, the IES Disclosure  Schedule or the Interstate
Disclosure Schedule,  no party  shall, nor  shall any  party permit  any of  its
Subsidiaries or, within the exercise of its best efforts, its Joint Ventures to,
enter  into any material  agreement or arrangement with  any of their respective
Affiliates (other  than  wholly-owned  Subsidiaries) on  terms  materially  less
favorable  to such party than could reasonably be expected to have been obtained
with an unaffiliated third party on an arm's-length basis.
 
    Section 7.17  COOPERATION, NOTIFICATION.  Each party shall, and shall  cause
its Subsidiaries and shall use its best efforts to cause, its Joint Ventures to
 
        (a)  cause its  appropriate representatives to  confer on  a regular and
    frequent basis  with one  or more  representatives of  each other  party  to
    discuss,  subject to  applicable law,  material operational  matters and the
    general status of its ongoing operations;
 
        (b) promptly notify each other party  of any significant changes in  its
    business,  properties, assets,  condition (financial  or other),  results of
    operations or prospects;
 
        (c) advise each other party  of any change or  event which has, had  or,
    insofar as reasonably can be foreseen, is reasonably likely to result in, in
    the  case of WPL, a WPL Material Adverse  Effect, in the case of IES, an IES
    Material Adverse  Effect,  or  in  the case  of  Interstate,  an  Interstate
    Material Adverse Effect; and
 
                                      A-54
<PAGE>
        (d) promptly provide each other party with copies of all filings made by
    such  party or  any of  its Subsidiaries  with any  state or  Federal court,
    administrative  agency,  commission  or  other  Governmental  Authority   in
    connection with this Agreement and the transactions contemplated hereby.
 
    Section 7.18  THIRD-PARTY CONSENTS.
 
        (a) WPL shall, and shall cause its Subsidiaries to, use all commercially
    reasonable  efforts to obtain all WPL  Required Consents. WPL shall promptly
    notify IES and Interstate  of any failure or  prospective failure to  obtain
    any  such consents  and, if  requested by  IES or  Interstate, shall provide
    copies of all WPL Required Consents obtained by WPL to IES and Interstate.
 
        (b) IES shall, and shall cause its Subsidiaries to, use all commercially
    reasonable efforts to obtain all  IES Required Consents. IES shall  promptly
    notify  WPL and Interstate  of any failure or  prospective failure to obtain
    any such consents  and, if  requested by  WPL or  Interstate, shall  provide
    copies of all IES Required Consents obtained by IES to WPL and Interstate.
 
        (c)  Interstate  shall, and  shall cause  its  Subsidiaries to,  use all
    commercially reasonable efforts to obtain all Interstate Required  Consents.
    Interstate  shall promptly notify WPL and  IES of any failure or prospective
    failure to obtain any such consents and,  if requested by WPL or IES,  shall
    provide copies of all Interstate Required Consents obtained by Interstate to
    WPL and IES.
 
    Section  7.19  NO BREACH.  No party shall, nor shall any party permit any of
its Subsidiaries  to, willfully  take any  action that  would or  is  reasonably
likely to result
 
        (a) in a material breach of any provision of this Agreement or the Stock
    Option Agreements, or
 
        (b)  in  any of  its representations  and warranties  set forth  in this
    Agreement or  the Stock  Option Agreements  being untrue  on and  as of  the
    Closing Date.
 
    Section 7.20  TAX-EXEMPT STATUS.  No party shall, nor shall any party permit
any  Subsidiary to take any action that would be reasonably likely to jeopardize
the qualification of  WP&LC's, Utilities's or  Interstate's outstanding  revenue
bonds  which qualify  on the  date hereof  under SECTION  142(a) of  the Code as
"EXEMPT FACILITY  BONDS" or  as tax-exempt  industrial development  bonds  under
SECTION 103(b)(4) of the Internal Revenue Code of 1954, as amended, prior to the
enactment of the Tax Reform Act of 1986.
 
    Section  7.21  TRANSITION STEERING  TEAM.  As soon  as practicable after the
date hereof, the parties  shall create a special  transition steering team  (the
"TRANSITION  TEAM") reporting to Erroll B.  Davis, Jr. ("MR. DAVIS") which shall
be chaired by Wayne H. Stoppelmoor ("MR. STOPPELMOOR") and include a designee of
each  of  IES,   WPL  and   Interstate.  The  Transition   Team  shall   develop
recommendations  concerning the future  structure and operations  of the Company
after the Effective Time, subject to applicable law.
 
    Section 7.22   COMPANY ACTIONS.   IES, WPL and  Interstate shall, and  shall
cause  their respective Subsidiaries  and shall use their  best efforts to cause
their respective  Joint Ventures  to, take  only those  actions, from  the  date
hereof until the Effective Time, that are required, permitted or contemplated by
this  Agreement to be taken  by any of them,  including, without limitation, the
declaration, filing or registration with, or notice to or authorization, consent
or approval of, any Governmental Authority, as set forth in SECTION 7.22 of  the
WPL  Disclosure  Schedule,  the  IES  Disclosure  Schedule  and  the  Interstate
Disclosure Schedule, respectively.
 
    Section 7.23  TAX MATTERS.   Except as set forth  in SECTION 7.23of the  WPL
Disclosure  Schedule, the IES  Disclosure Schedule or  the Interstate Disclosure
Schedule, no party shall make or rescind any material express or deemed election
relating to  taxes,  settle or  compromise  any material  claim,  action,  suit,
litigation,   proceeding,  arbitration,  investigation,   audit  or  controversy
relating to taxes, or change
 
                                      A-55
<PAGE>
any of its  methods of  reporting income or  deductions for  Federal income  tax
purposes from those employed in the preparation of its Federal income tax return
for  the taxable  year ending December  31, 1994,  except as may  be required by
applicable law.
 
    Section 7.24  DISCHARGE OF LIABILITIES.  No party shall, nor shall any party
permit its  Subsidiaries to,  pay,  discharge or  satisfy any  material  claims,
liabilities   or  obligations   (absolute,  accrued,   asserted  or  unasserted,
contingent or otherwise), other than the payment, discharge or satisfaction,  in
the  ordinary course of  business consistent with  past practice (which includes
the payment of  final and unappealable  judgments) or in  accordance with  their
terms,  of liabilities reflected or reserved against in, or contemplated by, the
most recent consolidated  financial statements  (or the notes  thereto) of  such
party  included in such party's  reports filed with the  SEC, or incurred in the
ordinary course of business consistent with past practice.
 
    Section 7.25  CONTRACTS.   No party  shall, nor shall  any party permit  its
Subsidiaries or, within the exercise of its best efforts, its Joint Ventures to,
except in the ordinary course of business consistent with past practice, modify,
amend,  terminate, renew or fail to use reasonable business efforts to renew any
material contract or  agreement to which  such party or  any Subsidiary of  such
party is a party or waive, release or assign any material rights or claims.
 
    Section 7.26  INSURANCE.  Each party shall, and shall cause its Subsidiaries
to, maintain with financially responsible insurance companies insurance coverage
in such amounts and against such risks and losses as are customary for companies
engaged  in  the electric  and  gas utility  industry  and employing  methods of
generating electric power and fuel sources similar to those methods employed and
fuels used by such party or its Subsidiaries.
 
    Section 7.27  PERMITS.  Each  party shall, and shall cause its  Subsidiaries
to,  use reasonable efforts to maintain  in effect all existing Permits pursuant
to which such party or its Subsidiaries operate.
 
                                  ARTICLE VIII
                             ADDITIONAL AGREEMENTS
 
    Section 8.1  ACCESS TO INFORMATION.
 
        (a) Upon  reasonable  notice, each  party  shall, and  shall  cause  its
    Subsidiaries  and, shall use  its best efforts to  cause, its Joint Ventures
    to, afford  to the  officers,  directors, employees,  accountants,  counsel,
    investment  bankers,  financial advisors  and  other representatives  of the
    other parties  (collectively, "REPRESENTATIVES")  reasonable access,  during
    normal  business hours throughout the period prior to the Effective Time, to
    all of its properties, books, contracts, commitments and records (including,
    but not limited to, Tax Returns) and, during such period, each party  shall,
    and shall cause its Subsidiaries to, furnish promptly to the other parties
 
           (i)  access  to each  report, schedule  and  other document  filed or
       received by it or any of its Subsidiaries and, within the exercise of its
       best efforts, its Joint Ventures pursuant to the requirements of  Federal
       or  state securities laws or filed with or sent to the SEC, the FERC, the
       NRC, the DOE, the  Department of Justice,  the Federal Trade  Commission,
       the Iowa Utilities Board, the Public Service Commission of Wisconsin, the
       Illinois  Commerce Commission, the  Minnesota Public Utilities Commission
       or any other Federal or state regulatory agency or commission, and
 
           (ii) access to  all information concerning  itself, its  Subsidiaries
       and,  within  the  exercise  of its  best  efforts,  its  Joint Ventures,
       directors, officers and  shareholders and  such other matters  as may  be
       reasonably  requested by any other party  in connection with any filings,
       applications or approvals required or  contemplated by this Agreement  or
       for  any other  reason related to  the transactions  contemplated by this
       Agreement.
 
                                      A-56
<PAGE>
        (b)  Each   party  shall,   and  shall   cause  its   Subsidiaries   and
    Representatives,  and shall use its best efforts to cause its Joint Ventures
    to, hold in strict confidence  all documents and information concerning  the
    others  furnished to it in connection  with the transactions contemplated by
    this Agreement  in  accordance  with the  Confidentiality  Agreement,  dated
    September 19, 1995, among WPL, IES and Interstate, as it may be amended from
    time to time (the "CONFIDENTIALITY AGREEMENT").
 
    Section 8.2  JOINT PROXY STATEMENT AND REGISTRATION STATEMENT.
 
        (a)  PREPARATION AND FILING.  The parties will prepare and file with the
    SEC as soon as reasonably practicable after the date hereof the Registration
    Statement  and the Proxy Statement  (together, the "JOINT PROXY/REGISTRATION
    STATEMENT"). The parties hereto shall  each use reasonable efforts to  cause
    the Registration Statement to be declared effective under the Securities Act
    as  promptly as practicable after such  filing. Each party hereto shall also
    take such action as may  reasonably be required to  cause the shares of  WPL
    Common  Stock issuable in connection with the Merger to be registered (or to
    obtain an exemption from registration) under applicable state "BLUE SKY"  or
    securities  laws;  PROVIDED, HOWEVER,  that no  party  shall be  required to
    register or qualify as a foreign  corporation or to take other action  which
    would subject it to service of process in any jurisdiction where it will not
    be,  following  the Merger,  so subject.  Each of  the parties  hereto shall
    furnish all information concerning itself which is required or customary for
    inclusion in the Joint Proxy/Registration  Statement. The parties shall  use
    reasonable  efforts to cause the shares of  WPL Common Stock issuable in the
    Merger to  be approved  for listing  on the  NYSE subject  only to  official
    notice  of issuance. The information provided by any party hereto for use in
    the Joint  Proxy/Registration Statement  shall be  true and  correct in  all
    material respects without omission of any material fact which is required to
    make  such information not false  or misleading. No representation, covenant
    or agreement  is  made by  any  party  hereto with  respect  to  information
    supplied  by any other  party for inclusion  in the Joint Proxy/Registration
    Statement.
 
        (b)  LETTER OF WPL'S ACCOUNTANTS.   WPL shall use best efforts to  cause
    to be delivered to IES and Interstate a letter of Arthur Andersen LLP, dated
    a   date  within   two  business   days  before   the  date   of  the  Joint
    Proxy/Registration Statement, and addressed to  IES and Interstate, in  form
    and  substance reasonably satisfactory to  IES and Interstate, and customary
    in scope and substance for  "COLD COMFORT" letters delivered by  independent
    public accountants in connection with registration statements on Form S-4.
 
        (c)   LETTER OF IES'S ACCOUNTANTS.   IES shall use best efforts to cause
    to be delivered to WPL and Interstate a letter of Arthur Andersen LLP, dated
    a  date  within   two  business   days  before   the  date   of  the   Joint
    Proxy/Registration  Statement, and addressed to  WPL and Interstate, in form
    and substance reasonably satisfactory to WPL and Interstate and customary in
    scope and  substance for  "COLD COMFORT"  letters delivered  by  independent
    public accountants in connection with registration statements on Form S-4.
 
        (d)   LETTER  OF INTERSTATE'S  ACCOUNTANTS.   Interstate shall  use best
    efforts to cause  to be  delivered to  WPL and IES  a letter  of Deloitte  &
    Touche  LLP, dated a  date within two  business days before  the date of the
    Joint Proxy/Registration Statement, and  addressed to WPL  and IES, in  form
    and  substance reasonably satisfactory to WPL and IES and customary in scope
    and substance for  "COLD COMFORT"  letters delivered  by independent  public
    accountants in connection with registration statements on Form S-4.
 
        (e)   FAIRNESS OPINIONS.  It shall be  a condition to the mailing of the
    Joint Proxy/Registration  Statement  to the  shareholders  of WPL,  IES  and
    Interstate that
 
           (i)  WPL shall have received an  opinion from Merrill, dated the date
       of the Joint Proxy/ Registration Statement, to the effect that, as of the
       date thereof, the IES Ratio and the Interstate Ratio are fair to WPL from
       a financial point of view,
 
                                      A-57
<PAGE>
           (ii) IES shall have received an  opinion from Morgan, dated the  date
       of the Joint Proxy/ Registration Statement, to the effect that, as of the
       date thereof, the IES Ratio, taking into account the Interstate Ratio, is
       fair  from a financial point of view  to the holders of IES Common Stock,
       and
 
          (iii) Interstate shall  have received an  opinion from Salomon,  dated
       the  date of the Joint Proxy/Registration  Statement, to the effect that,
       as of the date thereof, the  consideration to be received by the  holders
       of  Interstate  Common Stock  in  the Interstate  Merger  is fair  from a
       financial point of view to the holders of Interstate Common Stock.
 
    Section 8.3  REGULATORY MATTERS.
 
        (a)  HSR FILINGS.   Each party  hereto shall file or  cause to be  filed
    with  the  Federal  Trade  Commission  and  the  Department  of  Justice any
    notifications required to  be filed  by itself or  its respective  "ULTIMATE
    PARENT"  company under  the Hart-Scott-Rodino Antitrust  Improvements Act of
    1976, as amended (the "HSR ACT"), and the rules and regulations  promulgated
    thereunder  with  respect  to  the  transactions  contemplated  hereby. Such
    parties will use all  commercially reasonable efforts  to make such  filings
    within  200  days after  the date  hereof,  and to  respond promptly  to any
    requests for additional information made by either of such agencies.
 
        (b)  OTHER REGULATORY APPROVALS.  Each party hereto shall cooperate  and
    use   its  best  efforts   to  promptly  prepare   and  file  all  necessary
    documentation, to  effect all  necessary applications,  notices,  petitions,
    filings  and other documents, and to use all commercially reasonable efforts
    to obtain all necessary permits,  consents, approvals and authorizations  of
    all  Governmental  Authorities  necessary  or  advisable  to  consummate the
    Merger, including, without limitation, the WPL Required Statutory Approvals,
    the IES Required Statutory Approvals  and the Interstate Required  Statutory
    Approvals.
 
    Section 8.4  SHAREHOLDER APPROVAL
 
        (a)  APPROVAL OF IES SHAREHOLDERS.  Subject to the provisions of SECTION
    8.4(d)  and SECTION  8.4(e), IES  shall, as  soon as  reasonably practicable
    after the date hereof
 
           (i) take all steps  necessary to duly call,  give notice of,  convene
       and  hold  a  special  meeting  of  its  shareholders  (the  "IES SPECIAL
       MEETING") for the purpose of securing the IES Shareholders' Approval,
 
           (ii) distribute to its shareholders the Proxy Statement in accordance
       with applicable Federal and state law  and with its Restated Articles  of
       Incorporation and By-laws,
 
          (iii)  subject  to the  fiduciary duties  of  its Board  of Directors,
       recommend to  its  shareholders the  approval  of the  IES  Merger,  this
       Agreement and the transactions contemplated hereby, and
 
          (iv)  cooperate and  consult with WPL  and Interstate  with respect to
       each of the foregoing matters.
 
        (b)  APPROVAL OF WPL SHAREHOLDERS.  Subject to the provisions of SECTION
    8.4(d) and  SECTION 8.4(e),  WPL shall,  as soon  as reasonably  practicable
    after the date hereof
 
           (i)  take all steps  necessary to duly call,  give notice of, convene
       and hold  a  special  meeting  of  its  shareholders  (the  "WPL  SPECIAL
       MEETING") for the purpose of securing the WPL Shareholders' Approval,
 
           (ii) distribute to its shareholders the Proxy Statement in accordance
       with  applicable Federal and state law  and with its Restated Articles of
       Incorporation and By-laws,
 
          (iii) subject  to the  fiduciary  duties of  its Board  of  Directors,
       recommend  to its shareholders the approval of the Merger, this Agreement
       and the transactions contemplated hereby, and
 
                                      A-58
<PAGE>
          (iv) cooperate and  consult with  IES and Interstate  with respect  to
       each of the foregoing matters.
 
        (c)   APPROVAL OF INTERSTATE SHAREHOLDERS.  Subject to the provisions of
    SECTION 8.4(d) and SECTION 8.4(e),  Interstate shall, as soon as  reasonably
    practicable after the date hereof
 
           (i)  take all steps  necessary to duly call,  give notice of, convene
       and hold a special meeting  of its shareholders (the "INTERSTATE  SPECIAL
       MEETING")  for  the  purpose  of  securing  the  Interstate Shareholders'
       Approval,
 
           (ii) distribute to its shareholders the Proxy Statement in accordance
       with applicable Federal and state  law and with its Restated  Certificate
       of Incorporation and By-laws,
 
          (iii)  subject  to the  fiduciary duties  of  its Board  of Directors,
       recommend to its shareholders the approval of the Interstate Merger, this
       Agreement and the transactions contemplated hereby, and
 
          (iv) cooperate and consult  with IES and WPL  with respect to each  of
       the foregoing matters.
 
        (d)  MEETING DATE.  The IES Special Meeting, the WPL Special Meeting and
    the  Interstate Special Meeting shall be held  on such dates as WPL, IES and
    Interstate shall mutually determine.
 
        (e)  FAIRNESS OPINIONS NOT  WITHDRAWN.  It shall  be a condition to  the
    obligation  of  WPL to  hold the  WPL  Special Meeting  that the  opinion of
    Merrill, referred to in  SECTION 8.2(e), shall not  have been withdrawn,  it
    shall  be  a condition  to the  obligation of  IES to  hold the  IES Special
    Meeting that the opinion of Morgan, referred to in SECTION 8.2(e), shall not
    have been  withdrawn, and  it shall  be  a condition  to the  obligation  of
    Interstate  to  hold  the Interstate  Special  Meeting that  the  opinion of
    Salomon, referred to in SECTION 8.2(e), shall not have been withdrawn.
 
    Section 8.5  DIRECTOR AND OFFICER INDEMNIFICATION.
 
        (a)   INDEMNIFICATION.   To  the  extent, if  any,  not provided  by  an
    existing  right of  indemnification or other  agreement or  policy, from and
    after the Effective Time, the Company shall, to the fullest extent permitted
    by applicable law, indemnify,  defend and hold harmless  each person who  is
    now,  or has been at any time prior to the date hereof, or who becomes prior
    to the  Effective Time,  an officer,  director  or employee  of any  of  the
    parties   hereto  or  any  Subsidiary   (each  an  "INDEMNIFIED  PARTY"  and
    collectively, the "INDEMNIFIED PARTIES") against
 
           (i) all losses,  expenses (including reasonable  attorney's fees  and
       expenses),  claims, damages or liabilities or,  subject to the proviso of
       the next succeeding sentence, amounts paid in settlement, arising out  of
       actions  or omissions  occurring at or  prior to the  Effective Time (and
       whether asserted or  claimed prior to,  at or after  the Effective  Time)
       that  are, in whole or in part, based  on or arising out of the fact that
       such person is or was a director, officer or employee of such party  (the
       "INDEMNIFIED LIABILITIES"), and
 
           (ii) all Indemnified Liabilities to the extent that they are based on
       or  arise  out of  or pertain  to the  transactions contemplated  by this
       Agreement.
 
       In the  event of  any  such loss,  expense,  claim, damage  or  liability
       (whether or not arising before the Effective Time),
 
               (A)  the Company  shall pay the  reasonable fees  and expenses of
           counsel selected by the Indemnified  Parties, which counsel shall  be
           reasonably  satisfactory  to the  Company, promptly  after statements
           therefor are received and otherwise advance to such Indemnified Party
           upon  request   reimbursement  of   documented  expenses   reasonably
           incurred,
 
               (B) the Company will cooperate in the defense of any such matter,
           and
 
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<PAGE>
               (C) any determination required to be made with respect to whether
           an  Indemnified Party's conduct complies with the standards set forth
           under SECTIONS 180.0850 through 180.0859 of the WBCL and the Restated
           Articles of  Incorporation or  By-laws of  the Company  (as the  same
           shall  be amended  from time  to time)  shall be  made by independent
           counsel mutually acceptable to the Company and the Indemnified Party;
           PROVIDED, HOWEVER,  that the  Company  shall not  be liable  for  any
           settlement  effected without its written consent (which consent shall
           not be unreasonably withheld).
 
           The Indemnified Parties as a group may retain only one law firm  with
       respect to each related matter except to the extent that there is, in the
       opinion of counsel to an Indemnified Party, under applicable standards of
       professional  conduct,  a  conflict  on  any  significant  issue  between
       positions of such Indemnified  Party and any  other Indemnified Party  or
       Indemnified Parties.
 
        (b)  INSURANCE.  For a period of six years after the Effective Time, the
    Company  shall cause to  be maintained in effect  policies of directors' and
    officers' liability insurance maintained by WPL, IES and Interstate for  the
    benefit of those persons who are currently covered by such policies on terms
    no  less  favorable  than  the terms  of  such  current  insurance coverage;
    PROVIDED, HOWEVER, that the Company shall  not be required to expend in  any
    year  an amount in excess of 150% of the annual aggregate premiums currently
    paid by WPL, IES and Interstate  for such insurance; and PROVIDED,  FURTHER,
    that  if the annual premiums of  such insurance coverage exceed such amount,
    the Company shall  be obligated to  obtain a policy  with the best  coverage
    available,  in  the reasonable  judgment of  the Board  of Directors  of the
    Company, for a cost not exceeding such amount.
 
        (c)  SUCCESSORS.  In the event  the Company or any of its successors  or
    assigns  (i) consolidates with or merges into any other person and shall not
    be the continuing or surviving  corporation or entity of such  consolidation
    or  merger, or (ii) transfers all or substantially all of its properties and
    assets to any person, then and in either such case, proper provisions  shall
    be  made so that the successors and  assigns of the Company shall assume the
    obligations set forth in this SECTION 8.5.
 
        (d)  SURVIVAL OF  INDEMNIFICATION.  To the  fullest extent permitted  by
    law,  from and after the Effective Time, all rights to indemnification as of
    the date hereof in favor of the employees, agents, directors and officers of
    WPL, IES and Interstate  and their respective  Subsidiaries with respect  to
    their  activities as such prior to the  Effective Time, as provided in their
    respective articles  of incorporation  and  by-laws in  effect on  the  date
    thereof, or otherwise in effect on the date hereof, shall survive the Merger
    and  shall continue in full  force and effect for a  period of not less than
    six years from the Effective Time.
 
        (e)  BENEFIT.  The provisions of this SECTION 8.5 are intended to be for
    the benefit of, and shall be enforceable by, each Indemnified Party, his  or
    her heirs and his or her representatives.
 
    Section 8.6  DISCLOSURE SCHEDULES.  On the date hereof,
 
        (a)  IES has delivered to WPL and Interstate an IES Disclosure Schedule,
    accompanied by a certificate  signed by the chief  financial officer of  IES
    stating  the IES  Disclosure Schedule  is being  delivered pursuant  to this
    SECTION 8.6(a),
 
        (b) WPL has delivered to IES  and Interstate a WPL Disclosure  Schedule,
    accompanied  by  a  certificate  signed  by  the  Vice  President, Corporate
    Secretary and Treasurer of WPL stating the WPL Disclosure Schedule is  being
    delivered pursuant to this SECTION 8.6(b), and
 
        (c)  Interstate has  delivered to WPL  and IES  an Interstate Disclosure
    Schedule, accompanied by  a certificate  signed by  the principal  financial
    officer  of Interstate stating  the Interstate Disclosure  Schedule is being
    delivered pursuant to this SECTION 8.6(c).
 
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<PAGE>
        (d)  The WPL  Disclosure Schedule, the  IES Disclosure  Schedule and the
    Interstate Disclosure Schedule  are collectively referred  to herein as  the
    "DISCLOSURE SCHEDULES."
 
        (e)  The  Disclosure  Schedules  constitute  an  integral  part  of this
    Agreement and modify the  respective representations, warranties,  covenants
    or agreements of the parties hereto contained herein to the extent that such
    representations,  warranties, covenants or agreements expressly refer to the
    Disclosure Schedules. Anything to  the contrary contained  herein or in  the
    Disclosure    Schedules   notwithstanding,    any   and    all   statements,
    representations, warranties  or  disclosures  set forth  in  the  Disclosure
    Schedules shall be deemed to have been made on and as of the date hereof.
 
    Section  8.7   PUBLIC  ANNOUNCEMENTS.   Subject  to each  party's disclosure
obligations imposed by  law, WPL, IES  and Interstate will  cooperate with  each
other  in the development and distribution of all news releases and other public
information  disclosures  with  respect  to   this  Agreement  or  any  of   the
transactions  contemplated hereby and shall not issue any public announcement or
statement with  respect hereto  or  thereto without  the  consent of  the  other
parties (which consent shall not be unreasonably withheld).
 
    Section  8.8  RULE 145 AFFILIATES.   Within 30 days before the Closing Date,
WPL shall identify in a  letter to IES and Interstate,  IES shall identify in  a
letter  to WPL and Interstate, and Interstate  shall identify in a letter to WPL
and IES, all persons who are, and to such person's knowledge who will be at  the
Closing  Date, "AFFILIATES"  of WPL, IES  and Interstate,  respectively, as such
term is used in Rule 145 under the Securities Act (or otherwise under applicable
SEC  accounting  releases  with   respect  to  pooling-of-interests   accounting
treatment).  Each of WPL, IES and Interstate shall use all reasonable efforts to
cause their respective  affiliates (including any  person who may  be deemed  to
have  become an affiliate after the date of  the letter referred to in the prior
sentence) to deliver to the  Company on or prior to  the Closing Date a  written
agreement  substantially in the form attached  as Exhibit 8.8(a) with respect to
affiliates of  WPL and  Exhibit 8.8(b)  with respect  to affiliates  of IES  and
Interstate (each, an "AFFILIATE AGREEMENT").
 
    Section 8.9  EMPLOYEE AGREEMENTS AND WORKFORCE MATTERS.
 
        (a)  CERTAIN EMPLOYEE AGREEMENTS.  Subject to SECTION 8.10, SECTION 8.14
    and  SECTION 8.15,  the Company  and its  Subsidiaries shall  honor, without
    modification, all  contracts, agreements,  collective bargaining  agreements
    and  commitments of the parties prior to  the date hereof which apply to any
    current or former  employee or  current or  former director  of the  parties
    hereto;  PROVIDED, HOWEVER, that this undertaking is not intended to prevent
    the Company from enforcing such contracts, agreements, collective bargaining
    agreements and  commitments  in  accordance  with  their  terms,  including,
    without  limitation, any reserved right to amend, modify, suspend, revoke or
    terminate any such contract,  agreement, collective bargaining agreement  or
    commitment.
 
        (b)  WORKFORCE MATTERS.
 
           (i)  Subject to  applicable collective  bargaining agreements,  for a
       period of three  years following  the Effective Time,  any reductions  in
       workforce  in respect to employees of  the Company (except as provided in
       subparagraph (ii) below) shall be made on a fair and equitable basis,  in
       light  of the  circumstances and  the objectives  to be  achieved, giving
       consideration   to   previous   work   history,   job   experience    and
       qualifications,  without regard to whether employment was with WPL or its
       Subsidiaries, IES or its Subsidiaries, or Interstate or its Subsidiaries,
       and any employees whose employment  is terminated or jobs are  eliminated
       by  the Company or  any of its  Subsidiaries during such  period shall be
       entitled to  participate  on  a  fair and  equitable  basis  in  the  job
       opportunity  and employment placement programs  offered by the Company or
       any of its Subsidiaries. Any  workforce reductions carried out  following
       the  Effective Time by the Company and  its Subsidiaries shall be done in
       accordance with all applicable collective bargaining agreements, and  all
       laws and regulations
 
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<PAGE>
       governing  the employment relationship and termination thereof including,
       without limitation, the Worker Adjustment and Retraining Notification Act
       and regulations promulgated thereunder, and any comparable state or local
       law.
 
           (ii) During the three-year period ending on the third anniversary  of
       the  Closing Date,  the overall employment  levels of the  Company in the
       greater Dubuque area as  measured against such levels  as of the  Closing
       Date will not fall (for any reason whatsoever, including attrition of all
       types) below the following levels,
 
               (A) prior to the first anniversary of the Closing Date, 90%,
 
               (B) prior to the second anniversary of the Closing Date, 75%, and
 
               (C) prior to the third anniversary of the Closing Date, 60%.
 
    Section  8.10  EMPLOYEE BENEFIT PLANS.  Subject to SECTION 7.10, each of the
WPL Benefit Plans,  the IES Benefit  Plans and the  Interstate Benefit Plans  in
effect  at the  date hereof shall  be maintained  in effect with  respect to the
employees or former employees of WPL and any of its Subsidiaries, IES and any of
its Subsidiaries, and Interstate and any of its Subsidiaries, respectively,  who
are  covered by any such Benefit Plan immediately prior to the Closing Date (the
"AFFILIATED  EMPLOYEES")  until  the  Company  otherwise  determines  after  the
Effective Time; PROVIDED, HOWEVER, that nothing herein contained shall limit any
reserved  right contained  in any  such WPL  Benefit Plan,  IES Benefit  Plan or
Interstate Benefit Plan, to amend, modify, suspend, revoke or terminate any such
plan; PROVIDED, FURTHER,  HOWEVER, that  the Company or  its Subsidiaries  shall
provide  to the  Affiliated Employees  for a  period of  not less  than one year
following the Effective Time benefits, other than with respect to plans referred
to in SECTION  8.11, which are  no less  favorable in the  aggregate than  those
provided  under the WPL Benefit  Plans, the IES Benefit  Plans or the Interstate
Benefit Plans, as  the case may  be. Without limitation  of the foregoing,  each
participant of any such WPL Benefit Plan, IES Benefit Plan or Interstate Benefit
Plan  shall receive credit for purposes  of eligibility to participate, vesting,
benefit accrual and eligibility to receive benefits under a benefit plan of  the
Company  or any of its  Subsidiaries or Affiliates for  service credited for the
corresponding purpose  under such  benefit plan;  PROVIDED, HOWEVER,  that  such
crediting  of service  shall not  operate to duplicate  any benefit  to any such
participant or the funding for any such benefit. Any person hired by the Company
or any of its Subsidiaries  after the Closing Date who  was not employed by  any
party  hereto or its Subsidiaries immediately prior to the Closing Date shall be
eligible to participate in such benefit plans maintained, or contributed to,  by
the  Company or the  Subsidiary, division or  operation by which  such person is
employed, PROVIDED that such  person meets the  eligibility requirements of  the
applicable plan.
 
    Section 8.11  STOCK OPTION AND OTHER STOCK PLANS.
 
        (a)   AMENDMENT OF STOCK  PLANS AND AGREEMENTS.   Prior to the Effective
    Time, IES  shall amend  its Stock  Plan (as  hereinafter defined)  and  each
    underlying  award agreement to  provide that (i)  each outstanding option to
    purchase shares of IES Common Stock  (a "IES STOCK OPTION"), along with  any
    tandem  stock  appreciation right,  shall  constitute an  option  to acquire
    shares of  WPL  Common Stock,  on  the same  terms  and conditions  as  were
    applicable  under such IES Stock Option, based  on the same number of shares
    of WPL Common Stock as the holder  of such IES Stock Option would have  been
    entitled to receive pursuant to the Merger in accordance with Article II had
    such holder exercised such option in full immediately prior to the Effective
    Time;  PROVIDED, HOWEVER, that  the number of shares,  the option price, and
    the terms and conditions of exercise of such option, shall be determined  in
    a  manner that preserves  both (A) the  aggregate gain (or  loss) on the IES
    Stock Option immediately prior  to the Effective Time  and (B) the ratio  of
    the  exercise price  per share  of the  IES Stock  to the  fair market value
    (determined immediately prior to Effective  Time) per share subject to  such
    option;  and PROVIDED,  FURTHER, that  in the  case of  any option  to which
    SECTION 421 of the Code applies by reason of its qualification under any  of
    SECTIONS  422-424  of  the Code,  the  option  price, the  number  of shares
    purchasable pursuant to such option and the terms and conditions of exercise
    of such option shall be determined in order to
 
                                      A-62
<PAGE>
    comply with SECTION  424(a) of  the Code;  and (ii)  each other  outstanding
    award  under the IES Stock Plan (the "IES STOCK AWARDS") shall constitute an
    award based upon the same number of shares of WPL Common Stock as the holder
    of such IES Stock Award would have been entitled to receive pursuant to  the
    Merger  in  accordance with  Article II  had such  holder been  the absolute
    owner, immediately before the  Effective Time, of the  shares of IES  Common
    Stock  on which  such IES Stock  Award is  based, and otherwise  on the same
    terms and conditions as governed by such IES Stock Award immediately  before
    the  Effective Time.  At the Effective  Time, the Company  shall assume each
    stock award  agreement  relating  to  the IES  Stock  Plan,  as  amended  as
    previously  provided. As soon  as practicable after  the Effective Time, the
    Company shall deliver  to the  holders of IES  Stock Options  and IES  Stock
    Awards  appropriate notices setting forth  such holders' rights with respect
    to such options  and awards  after the  Effective Time  and each  underlying
    stock award agreement, each as assumed by the Company.
 
        (b)   COMPANY ACTION.  After the Effective Time, with respect to the IES
    Stock Plan, and any other plans under which the delivery of WPL Common Stock
    is required upon payment of benefits, grant of awards or exercise of options
    (the "STOCK PLANS"), the Company  shall take all corporate action  necessary
    or appropriate to
 
           (i)  obtain shareholder approval  with respect to  such Stock Plan to
       the extent such approval  is required for purposes  of the Code or  other
       applicable  law, or to enable  such Stock Plan to  comply with Rule 16b-3
       promulgated under the Exchange Act,
 
           (ii) reserve  for issuance  under such  plan or  otherwise provide  a
       sufficient number of shares of WPL Common Stock for delivery upon payment
       of  benefits, grant  of awards  or exercise  of options  under such Stock
       Plan, and
 
          (iii)  as  soon  as  practicable   after  the  Effective  Time,   file
       registration  statements on Form S-3 or Form  S-8, as the case may be (or
       any successor or other appropriate forms), with respect to the shares  of
       WPL  Common  Stock  subject  to  such  Stock  Plan  to  the  extent  such
       registration statement is required under applicable law, and the  Company
       shall  use  its  best  efforts  to  maintain  the  effectiveness  of such
       registration  statements  (and  maintain   the  current  status  of   the
       prospectuses  contained therein) for so long  as such benefits and grants
       remain payable and such options remain outstanding.
 
    With respect  to those  individuals who  subsequent to  the Merger  will  be
    subject  to the reporting  requirements under SECTION  16(a) of the Exchange
    Act, the Company shall  administer the Stock Plans,  where applicable, in  a
    manner that complies with Rule 16b-3 promulgated under the Exchange Act.
 
    Section 8.12  NO SOLICITATIONS.
 
        (a)  No  party hereto  shall, and  each  such party  shall use  its best
    efforts to cause its Subsidiaries not to, permit any of its Representatives,
    directly or indirectly initiate, solicit or encourage, or take any action to
    facilitate the  making of  any offer  or proposal  which constitutes  or  is
    reasonably  likely  to  lead  to,  any  Business  Combination  Proposal  (as
    hereinafter  defined),  or,  in  the   event  of  an  unsolicited   Business
    Combination  Proposal,  except to  the  extent required  by  their fiduciary
    duties under applicable law  if so advised in  a written opinion of  outside
    counsel,  engage in negotiations  or provide any information  or data to any
    person relating to any Business Combination Proposal.
 
        (b) Each  party hereto  shall notify  the other  parties orally  and  in
    writing  of  any such  inquiries,  offers or  proposals  (including, without
    limitation, the terms and conditions of  any such proposal and the  identity
    of the person making it), within 24 hours of the receipt thereof, shall keep
    the  other parties informed of  the status and details  of any such inquiry,
    offer or  proposal, and  shall give  the other  parties five  days'  advance
    notice  of any agreement  to be entered  into with or  any information to be
    supplied to any person  making such inquiry, offer  or proposal. Each  party
 
                                      A-63
<PAGE>
    hereto  shall  immediately cease  and cause  to  be terminated  all existing
    discussions and negotiations, if any, with any parties conducted  heretofore
    with respect to any Business Combination Proposal.
 
        (c)  As used in this SECTION 8.12, "BUSINESS COMBINATION PROPOSAL" shall
    mean any tender or exchange offer,  proposal for a merger, consolidation  or
    other  business combination involving any party  to this Agreement or any of
    its material Subsidiaries, or any proposal  or offer (in each case,  whether
    or  not in  writing and whether  or not  delivered to the  shareholders of a
    party generally)  to  acquire  in  any manner,  directly  or  indirectly,  a
    substantial equity interest in or a substantial portion of the assets of any
    party  to this  Agreement or  any of  its material  Subsidiaries, other than
    pursuant to the transactions contemplated by this Agreement.
 
        (d) Nothing  contained herein  shall prohibit  a party  from taking  and
    disclosing  to  its shareholders  a position  contemplated by  Rule 14e-2(a)
    under the Exchange Act with respect to a Business Combination Proposal  made
    by means of a tender offer.
 
    Section 8.13  COMPANY BOARD OF DIRECTORS.
 
        (a)  WPL's, IES's and  Interstate's respective Boards  of Directors will
    take such  action as  may be  necessary  to cause  the number  of  directors
    comprising  the full Board of Directors of the Company at the Effective Time
    to be  fifteen (15)  persons.  The directors  shall  be divided  into  three
    classes  (hereafter referred to as "CLASS I," "CLASS II" and "CLASS III") of
    five directors  each.  Class I  directors  shall  be appointed  for  a  term
    expiring  at  the  first  annual  meeting  of  shareholders  of  the Company
    following the Effective Time,  Class II directors shall  be appointed for  a
    term  expiring at the  second annual meeting of  shareholders of the Company
    following the Effective Time, and Class III directors shall be appointed for
    a term expiring at the third  annual meeting of shareholders of the  Company
    following  the  Effective  Time, and  in  each case  until  their respective
    successors have been duly elected and qualified. Of the directors comprising
    Class I, two shall  be designated by each  of IES and WPL  and one shall  be
    designated  by  Interstate prior  to the  Effective  Time. Of  the directors
    comprising Class II, two shall be designated by each of IES and WPL, and one
    shall be designated  by Interstate prior  to the Effective  Time. Class  III
    directors  shall  consist  of  Lee  Liu  ("MR.  LIU"),  Mr.  Davis  and  Mr.
    Stoppelmoor as well as two additional directors, one director designated  by
    each  of IES and  WPL prior to  the Effective Time.  Directors designated by
    IES,  WPL  and  Interstate  (including  their  successors)  are  hereinafter
    sometimes   referred  to  as  the   "IES  DIRECTORS,"  "WPL  DIRECTORS"  and
    "INTERSTATE DIRECTORS,"  respectively.  Notwithstanding the  foregoing,  if,
    prior  to the  Effective Time,  any of  such designees  shall decline  or be
    unable to serve,  the respective  party which designated  such person  shall
    designate  another  person to  serve in  such  person's stead.  In addition,
    subject to  the limitations  set  forth in  SECTION  8.13(B), for  a  period
    commencing  as of the Effective  Time and expiring on  the date of the third
    annual meeting of shareholders of the Company following the Effective  Time,
    the  IES, WPL and Interstate  Directors (each as a  separate group) shall be
    entitled to nominate  those persons who  will be eligible  to be  appointed,
    elected  or re-elected as  IES, WPL and  Interstate Directors, respectively.
    For purposes of this Agreement, Messrs. Liu, Davis and Stoppelmoor shall  be
    deemed  to have  been designated by  IES, WPL  and Interstate, respectively.
    WPL's, IES's and Interstate's respective Boards of Directors will also  take
    such  action  as  may  be  necessary  to  cause  the  Nominating,  Audit and
    Compensation Committees of  the Board  of Directors  of the  Company at  the
    Effective   Time  to  consist  proportionally   (to  the  extent  reasonably
    practicable) of designees of each of WPL, IES and Interstate.
 
        (b) For a period of five  years following the Effective Time, no  person
    who  is  an executive  officer  or employee  of the  Company  or any  of its
    Subsidiaries shall be eligible to serve as a director of the Company, except
    for Messrs. Liu, Davis and Stoppelmoor; PROVIDED, HOWEVER, that if Mr. Davis
    is not  then  serving  as  Chief  Executive  Officer  of  the  Company,  the
    individual serving in such capacity shall be eligible to serve as a director
    of the Company.
 
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<PAGE>
        (c)  Meetings  of  the  Board  of  Directors  of  the  Company  shall be
    reasonably rotated among the WPL, IES  and Interstate cities for so long  as
    separate utility headquarters exist in those cities.
 
    Section  8.14   COMPANY OFFICERS.   At the  Effective Time,  pursuant to the
terms hereof and of the employment contracts referred to in SECTION 8.15:
 
        (a) Mr.  Liu  shall  hold the  position  of  Chairman of  the  Board  of
    Directors  and shall be entitled  to serve in such  capacity for a period of
    two years  from the  Effective Time,  after  which time  he will  retire  as
    Chairman  of the Board of Directors of  the Company but he shall continue to
    be eligible to serve as a director.
 
        (b) Mr. Davis shall  hold the positions of  Chief Executive Officer  and
    President  for a period of at least five years from the Effective Time. When
    Mr. Liu no longer serves  as Chairman of the  Board of Directors, Mr.  Davis
    shall  be entitled to continue  to serve in his  capacity as Chief Executive
    Officer and President,  and shall  also serve as  Chairman of  the Board  of
    Directors  for at least the remainder of the five year term specified above.
    Subject to the five-year term specified  above, Mr. Davis shall be  entitled
    to  serve in all  of the above-referenced capacities  until his successor is
    elected or appointed and  shall have qualified in  accordance with the  WBCL
    and  the Restated Articles  of Incorporation and By-laws  of the Company (as
    the same shall be amended pursuant to SECTION 8.19). In addition, Mr.  Davis
    shall  hold the positions  of Chief Executive Officer  of each of Utilities,
    WP&LC, Interstate and the Nonregulated Company (as hereinafter defined), and
    shall be entitled to serve  in such capacities for  a period of three  years
    from the Effective Time and until his successor is duly elected or appointed
    and qualified in accordance with applicable charter documents and law.
 
        (c)  Mr. Stoppelmoor  shall hold  the position  of Vice  Chairman of the
    Board of Directors of  the Company and  shall be entitled  to serve in  such
    capacity  for a period  of two years  after the Effective  Time, after which
    time he shall retire as Vice Chairman, but he shall continue to be  eligible
    to serve as a director.
 
        (d)  Mr.  Michael R.  Chase  ("MR. CHASE")  shall  hold the  position of
    President of Interstate and shall be entitled to serve in such capacity  for
    a period of at least three years after the Effective Time.
 
        (e)  Mr.  Lance  W. Ahearn  ("MR.  AHEARN")  shall be  appointed  to the
    position of  President  and  Chief Operating  Officer  of  the  Nonregulated
    Company as of the Effective Time.
 
        (f)  Subject  to SECTION  8.14(g), if  any of  the foregoing  persons is
    unable or unwilling to  hold such offices for  the periods set forth  above,
    his  successor shall be selected by the Board of Directors of the Company in
    accordance with its By-laws.
 
        (g) For a period of five years following the Effective Time, a  majority
    vote  of the WPL Directors  or the successors thereto  shall, in addition to
    any other vote required by law, be  required to appoint or elect any  person
    other than Mr. Davis as Chief Executive Officer of the Company.
 
    Section  8.15   EMPLOYMENT CONTRACTS.   WPL,  or in  the case  of Mr. Chase,
Interstate, shall, as of or prior  to the Effective Time, enter into  employment
contracts  with each of Messrs.  Liu, Davis, Stoppelmoor and  Chase in the forms
set forth in EXHIBIT 8.15.1, 8.15.2, 8.15.3 and 8.15.4, respectively.
 
    Section 8.16   POST-MERGER OPERATIONS.   Following the  Effective Time,  the
Company  shall conduct its operations or take such action in accordance with the
following:
 
        (a) the Company shall maintain  its headquarters in Madison,  Wisconsin,
    but  this  location will  be evaluated  over time  as future  business needs
    dictate.
 
        (b)  during  the  three-year   period  following  the  Effective   Time,
    Utilities,  WP&LC, and  Interstate shall  maintain their  separate corporate
    existences and shall maintain their headquarters in their present  locations
    of Cedar Rapids, Iowa, Madison, Wisconsin and Dubuque, Iowa, respectively;
 
                                      A-65
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        (c)  immediately following the  Effective Time, the  Company shall cause
    the IES  nonregulated  holding  company  to merge  with  and  into  the  WPL
    nonregulated  holding  company, with  the  WPL nonregulated  holding company
    being the surviving corporation (the combined company is herein referred  to
    as the "NONREGULATED COMPANY"); and
 
        (d) during the five-year period following the Effective Time or for such
    shorter  period as the following  entities maintain their separate corporate
    existences, the  Company shall  use  its best  efforts  to insure  that  the
    composition  of  the Board  of  Directors of  each  of Utilities,  WP&LC and
    Interstate and Nonregulated Company will be identical to the composition  of
    the Board of Directors of the Company.
 
    Section  8.17  EXPENSES.   Subject to  SECTION 10.3, all  costs and expenses
incurred in connection  with this  Agreement and  the transactions  contemplated
hereby  shall be paid  by the party  incurring such expenses,  except that those
expenses incurred  in connection  with printing  the Joint  Proxy/  Registration
Statement,  as well as the  filing fee relating thereto,  shall be shared by the
parties in the following proportions: 43% by  WPL, 14% by Interstate and 43%  by
IES.
 
    Section  8.18   FURTHER ASSURANCES.   Each  party will,  and will  cause its
Subsidiaries and, will  use its  best efforts to  cause its  Joint Ventures  to,
execute  such further documents and instruments and take such further actions as
may  reasonably  be  requested  by  the  terms  hereof.  The  parties  expressly
acknowledge  and agree that, although it is  their current intention to effect a
business  combination  among  themselves  in  the  form  contemplated  by   this
Agreement,  it may  be preferable to  effectuate such a  business combination by
means of  an alternative  structure in  light  of the  conditions set  forth  in
SECTION  9.1(e), SECTION 9.2(e), SECTION 9.2(f), SECTION 9.3(e), SECTION 9.3(f),
SECTION 9.4(e) and SECTION  9.4(f). Accordingly, if the  only conditions to  the
parties'  obligations to consummate the Merger which are not satisfied or waived
are receipt  of any  one or  more of  the WPL  Required Consents,  WPL  Required
Statutory  Approvals, IES  Required Consents, IES  Required Statutory Approvals,
Interstate Required  Consents, Interstate  Required Statutory  Approvals or  the
opinions referred to in SECTIONS 9.2(e), 9.3(e), and 9.4(e), and the adoption of
an  alternative structure (that  otherwise substantially preserves  for WPL, IES
and Interstate the  economic and other  material benefits of  the Merger)  would
result  in such conditions being satisfied or waived, then the parties shall use
their respective best efforts to effect a business combination among  themselves
by  means of  a mutually  agreed upon  structure other  than the  Merger that so
preserves such benefits; provided that,  prior to closing any such  restructured
transaction,  all material third party  and Governmental Authority declarations,
filings, registrations, notices, authorizations, consents or approvals necessary
to effect such alternative business combination shall have been obtained and all
other conditions  to  the parties'  obligations  to consummate  the  Merger,  as
applied  to such alternative business combination,  shall have been satisfied or
waived.
 
    Section 8.19   CHARTER AND  BY-LAW AMENDMENTS.   Prior to  the Closing,  WPL
shall  cause  its  Articles  of  Incorporation  and  By-laws  to  be  amended as
contemplated in Section 8.19 of the WPL Disclosure Schedule.
 
    Section 8.20  IES RIGHTS AGREEMENT.  Prior to or at the time of the Closing,
IES shall amend the IES Rights Agreement  to cause it to terminate effective  as
of the Effective Time.
 
                                   ARTICLE IX
                                   CONDITIONS
 
    Section   9.1    CONDITIONS  TO  EACH   PARTY'S  OBLIGATION  TO  EFFECT  THE
MERGER.  The respective obligations of each party to effect the Merger shall  be
subject  to the satisfaction  on or prior  to the Closing  Date of the following
conditions, except,  to  the  extent  permitted by  applicable  law,  that  such
conditions may be waived in writing pursuant to SECTION 10.5 by the joint action
of the parties hereto:
 
        (a)    SHAREHOLDER  APPROVALS.    The  IES  Shareholders'  Approval, the
    Interstate Shareholders' Approval and  the WPL Shareholders' Approval  shall
    have been obtained.
 
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        (b)   NO INJUNCTION.   No temporary restraining  order or preliminary or
    permanent injunction or other order by any Federal or state court preventing
    consummation of the Merger (including either  or both of the IES Merger  and
    the  Interstate Merger) shall have been  issued and be continuing in effect,
    and the  Merger  (including  either  or  both of  the  IES  Merger  and  the
    Interstate  Merger) and the other transactions contemplated hereby shall not
    have  been  prohibited  under  any  applicable  Federal  or  state  law   or
    regulation.
 
        (c)    REGISTRATION STATEMENT.   The  Registration Statement  shall have
    become effective in accordance  with the provisions  of the Securities  Act,
    and  no stop order suspending such  effectiveness shall have been issued and
    remain in effect.
 
        (d)  LISTING OF SHARES.  The shares of WPL Common Stock issuable in  the
    Merger  pursuant to Article II  shall have been approved  for listing on the
    NYSE subject only to official notice of issuance.
 
        (e)  STATUTORY APPROVALS.
 
           (i) The WPL Required Statutory Approvals, the IES Required  Statutory
       Approvals and the Interstate Required Statutory Approvals shall have been
       obtained  at or  prior to the  Effective Time, such  approvals shall have
       become Final Orders (as hereinafter defined) and such Final Orders  shall
       not  impose terms or conditions which,  in the aggregate have, or insofar
       as reasonably can be foreseen, would  have, a material adverse effect  on
       the  business, assets,  financial condition  or results  of operations or
       prospects of the Company or  which would be materially inconsistent  with
       the agreements of the parties contained herein.
 
           (ii)  As used  in this Agreement,  "FINAL ORDER" means  action by the
       relevant regulatory  authority  which  has  not  been  reversed,  stayed,
       enjoined,  set aside,  annulled or suspended,  with respect  to which any
       waiting period  prescribed by  law before  the transactions  contemplated
       hereby  may be consummated has expired, and as to which all conditions to
       the consummation of  such transactions prescribed  by law, regulation  or
       order have been satisfied.
 
        (f)   POOLING.   Each of WPL,  IES and Interstate  shall have received a
    letter of its  independent public  accountants, dated the  Closing Date,  in
    form  and substance reasonably  satisfactory, in each case,  to WPL, IES and
    Interstate,  stating  that  the  transactions  effected  pursuant  to   this
    Agreement  will qualify  as a pooling  of interests  transaction pursuant to
    GAAP and applicable SEC regulations.
 
    Section 9.2   FURTHER  CONDITIONS TO  OBLIGATION OF  IES TO  EFFECT THE  IES
MERGER.  The obligation of IES to effect the IES Merger shall be further subject
to  the  satisfaction,  on  or  prior to  the  Closing  Date,  of  the following
conditions, except as may be waived by IES in writing pursuant to SECTION 10.5:
 
        (a)    PERFORMANCE  OF  OBLIGATIONS.     WPL  (and/or  its   appropriate
    Subsidiaries) and Interstate (and/or its appropriate Subsidiaries) will have
    performed  their agreements and covenants contained  in SECTIONS 7.3 and 7.4
    and will have performed in all material respects their other agreements  and
    covenants  contained in or  contemplated by this  Agreement, and the WPL/IES
    and Interstate/IES Stock Option Agreements required to be performed by  each
    of them at or prior to the Effective Time.
 
        (b)  REPRESENTATIONS AND WARRANTIES.  The representations and warranties
    of  WPL and Interstate set forth in this Agreement shall be true and correct
    (i) on and as of the date hereof and (ii) on and as of the Closing Date with
    the same effect as though such representations and warranties had been  made
    on  and as  of the Closing  Date (except for  representations and warranties
    that expressly speak only as of a specific date or time other than the  date
    hereof  or the Closing Date  which need only be true  and correct as of such
    date or time)  except in each  of cases (i)  and (ii) for  such failures  of
    representations  or warranties to be true and correct (without regard to any
 
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    materiality qualifications contained therein) which, individually or in  the
    aggregate  do not,  and insofar  as reasonably  can be  foreseen, would not,
    result in a WPL  Material Adverse Effect or  an Interstate Material  Adverse
    Effect, as the case may be.
 
        (c)  CLOSING CERTIFICATES.  IES shall have received a certificate signed
    by  the chief  financial officer  of each of  WPL and  Interstate, dated the
    Closing  Date,  to  the  effect  that,  to  such  officer's  knowledge,  the
    conditions  set forth in  SECTION 9.2(a) and SECTION  9.2(b) with respect to
    WPL or Interstate, as the case may be, have been satisfied.
 
        (d)   MATERIAL  ADVERSE EFFECT.    No  WPL Material  Adverse  Effect  or
    Interstate  Material  Adverse Effect  shall have  occurred, and  there shall
    exist no facts  or conditions  (other than  facts or  conditions of  general
    applicability  to electric utility companies in the region in which WPL, IES
    and Interstate conduct their utility  operations) which have, or insofar  as
    reasonably  can be foreseen, would have a  WPL Material Adverse Effect or an
    Interstate Material Adverse Effect, as the case may be.
 
        (e)  TAX OPINIONS.
 
           (i) IES shall have received an opinion of Winthrop, Stimson, Putnam &
       Roberts dated as of the Closing Date,  to the effect that the IES  Merger
       will  be treated as a tax-free reorganization under SECTION 368(a) of the
       Code, and
 
           (ii) IES and Winthrop, Stimson, Putnam  & Roberts shall have had  the
       opportunity  to review the tax opinions of Interstate's and WPL's special
       tax counsel  received  pursuant  to  SECTIONS  9.3(e)(i)  and  9.4(e)(i),
       respectively,  including the representations,  covenants or other matters
       in reliance  on which  the  opinions are  being  rendered, and  shall  be
       reasonably satisfied with the completeness and accuracy of said opinions.
 
        (f)   REQUIRED CONSENTS.   The WPL Required  Consents and the Interstate
    Required Consents, the failure of which to obtain would have a WPL  Material
    Adverse  Effect or  an Interstate Material  Adverse Effect,  shall have been
    obtained.
 
        (g)    AFFILIATE  AGREEMENTS.     WPL  shall  have  received   Affiliate
    Agreements,   duly  executed  by  each  Affiliate  of  WPL  and  Interstate,
    substantially in  the form  of  Exhibit 8.8(a)  or  8.8(b), as  provided  in
    SECTION 8.8.
 
    Section  9.3  FURTHER  CONDITIONS TO OBLIGATION OF  INTERSTATE TO EFFECT THE
INTERSTATE MERGER.  The obligation of Interstate to effect the Interstate Merger
shall be further subject to the satisfaction,  on or prior to the Closing  Date,
of  the following conditions, except  as may be waived  by Interstate in writing
pursuant to SECTION 10.5:
 
        (a)    PERFORMANCE  OF  OBLIGATIONS.     IES  (and/or  its   appropriate
    Subsidiaries)  and  WPL (and/  or  its appropriate  Subsidiaries)  will have
    performed their agreements and covenants  contained in SECTIONS 7.3 and  7.4
    and  will have performed in all material respects their other agreements and
    covenants  contained  in   or  contemplated  by   this  Agreement  and   the
    IES/Interstate  and WPL/  Interstate Stock  Option Agreement  required to be
    performed by each of them at or prior to the Effective Time.
 
        (b)  REPRESENTATIONS AND WARRANTIES.  The representations and warranties
    of IES and WPL set forth in this Agreement shall be true and correct (i)  on
    and  as of the date hereof  and (ii) on and as  of the Closing Date with the
    same effect as though such representations  and warranties had been made  on
    and  as of the Closing Date  (except for representations and warranties that
    expressly speak only  as of  a specific  date or  time other  than the  date
    hereof  or the Closing Date  which need only be true  and correct as of such
    date or time)  except in each  of cases (i)  and (ii) for  such failures  of
    representations  or warranties to be true and correct (without regard to any
    materiality qualifications contained therein) which, individually or in  the
    aggregate  do not,  and insofar  as reasonably  can be  foreseen, would not,
    result in an IES Material Adverse  Effect or a WPL Material Adverse  Effect,
    as the case may be.
 
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<PAGE>
        (c)  CLOSING CERTIFICATES.  Interstate shall have received a certificate
    signed  by the  chief financial officer  of each  of IES and  WPL, dated the
    Closing  Date,  to  the  effect  that,  to  such  officer's  knowledge,  the
    conditions  set forth in  SECTION 9.3(a) and SECTION  9.3(b) with respect to
    WPL or IES, as the case may be, have been satisfied.
 
        (d)  MATERIAL  ADVERSE EFFECT.   No IES Material  Adverse Effect or  WPL
    Material  Adverse Effect shall have occurred, and there shall exist no facts
    or conditions (other than  facts or conditions  of general applicability  to
    electric  utility companies in  the region in which  WPL, IES and Interstate
    conduct their utility operations) which  have, or insofar as reasonably  can
    be  foreseen, would have  an IES Material  Adverse Effect or  a WPL Material
    Adverse Effect, as the case may be.
 
        (e)  TAX OPINIONS.
 
           (i) Interstate  shall have  received an  opinion of  Milbank,  Tweed,
       Hadley  & McCloy  dated as of  the Closing  Date, to the  effect that the
       Interstate Merger  will be  treated as  a tax-free  reorganization  under
       SECTION 368(a) of the Code; and
 
           (ii)  Interstate and Milbank,  Tweed, Hadley &  McCloy shall have had
       the opportunity to review the tax opinions of IES's and WPL's special tax
       counsel  received   pursuant  to   SECTIONS  9.2(e)(i)   and   9.4(e)(i),
       respectively,  including the representations,  covenants or other matters
       in reliance  on which  the  opinions are  being  rendered, and  shall  be
       reasonably satisfied with the completeness and accuracy of said opinions.
 
        (f)   REQUIRED CONSENTS.  The IES Required Consents and the WPL Required
    Consents, the failure of which to obtain would have an IES Material  Adverse
    Effect or a WPL Material Adverse Effect, shall have been obtained.
 
        (g)     AFFILIATE  AGREEMENTS.     WPL  shall  have  received  Affiliate
    Agreements, duly executed by each Affiliate of IES and WPL, substantially in
    the form of Exhibit 8.8(a) and 8.8(b), as provided in SECTION 8.8.
 
    Section 9.4    FURTHER  CONDITIONS  TO  OBLIGATION  OF  WPL  TO  EFFECT  THE
MERGER.   The obligation of WPL to effect the Merger shall be further subject to
the satisfaction, on or prior to the Closing Date, of the following  conditions,
except as may be waived by WPL in writing pursuant to SECTION 10.5:
 
        (a)     PERFORMANCE  OF  OBLIGATIONS.     IES  (and/or  its  appropriate
    Subsidiaries) and Interstate (and/or its appropriate Subsidiaries) will have
    performed their agreements and covenants  contained in Sections 7.3 and  7.4
    and  will have performed in all material respects their other agreements and
    covenants contained in or contemplated by this Agreement and the IES/WPL and
    Interstate/WPL Stock Option Agreements required to be performed by it at  or
    prior to the Effective Time.
 
        (b)  REPRESENTATIONS AND WARRANTIES.  The representations and warranties
    of  IES and Interstate set forth in this Agreement shall be true and correct
    (i) on and as of the date hereof and (ii) on and as of the Closing Date with
    the same effect as though such representations and warranties had been  made
    on  and as  of the Closing  Date (except for  representations and warranties
    that expressly speak only as of a specific date or time other than the  date
    hereof  or the Closing Date  which need only be true  and correct as of such
    date or time)  except in each  of cases (i)  and (ii) for  such failures  of
    representations  or warranties to be true and correct (without regard to any
    materiality qualifications contained therein) which, individually or in  the
    aggregate  do not,  and insofar  as reasonably  can be  foreseen, would not,
    result in an IES Material Adverse  Effect or an Interstate Material  Adverse
    Effect, as the case may be.
 
        (c)  CLOSING CERTIFICATES.  WPL shall have received a certificate signed
    by  the chief  financial officer  of each of  IES and  Interstate, dated the
    Closing  Date,  to  the  effect  that,  to  such  officer's  knowledge,  the
    conditions  set forth in  SECTION 9.4(a) and SECTION  9.4(b) with respect to
    IES or Interstate, as the case may be, have been satisfied.
 
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<PAGE>
        (d)   MATERIAL  ADVERSE EFFECT.    No  IES Material  Adverse  Effect  or
    Interstate  Material  Adverse Effect  shall have  occurred, and  there shall
    exist no facts  or conditions  (other than  facts or  conditions of  general
    applicability  to electric utility companies in the region in which WPL, IES
    and Interstate conduct their utility  operations) which have, or insofar  as
    reasonably  can be foreseen, would have an IES Material Adverse Effect or an
    Interstate Material Adverse Effect, as the case may be.
 
        (e)  TAX OPINIONS.
 
           (i) WPL shall have received an opinion of Foley & Lardner dated as of
       the Closing Date,  to the effect  that the  Merger will be  treated as  a
       tax-free reorganization under Section 368(a) of the Code; and
 
           (ii) WPL and Foley & Lardner shall have had the opportunity to review
       the  tax opinions of  IES's and Interstate's special  tax counsel, as set
       forth in Sections  9.2(e)(i) and 9.3(e)(i),  respectively, including  the
       representations,  covenants  or other  matters in  reliance on  which the
       opinions are being rendered, and  shall be reasonably satisfied with  the
       completeness and accuracy of said opinions.
 
        (f)   REQUIRED CONSENTS.   The IES Required  Consents and the Interstate
    Required Consents, the failure of which to obtain would have an IES Material
    Adverse Effect or  an Interstate  Material Adverse Effect,  shall have  been
    obtained.
 
        (g)     AFFILIATE  AGREEMENTS.     WPL  shall  have  received  Affiliate
    Agreements,  duly  executed  by  each  Affiliate  of  IES  and   Interstate,
    substantially in the form of Exhibit 8.8(b), as provided in Section 8.8.
 
                                   ARTICLE X
                       TERMINATION, AMENDMENT AND WAIVER
 
    Section  10.1  TERMINATION.   This Agreement  may be terminated  at any time
prior to the Closing Date, whether before or after approval by the  shareholders
of the respective parties hereto contemplated by this Agreement:
 
        (a) by mutual written consent of WPL, IES and Interstate;
 
        (b)  by any party hereto, by written notice to the other parties, if the
    Effective Time  shall not  have occurred  on  or before  May 10,  1997  (the
    "INITIAL  TERMINATION DATE"); provided, however, that the right to terminate
    the Agreement under this SECTION 10.(b) shall not be available to any  party
    whose  failure to fulfill  any obligation under this  Agreement has been the
    cause of, or resulted in, the failure  of the Effective Time to occur on  or
    before  the Initial Termination Date; and  PROVIDED, FURTHER, that if on the
    Initial Termination Date the conditions to the Closing set forth in SECTIONS
    9.1(e), 9.2(f), 9.3(f) and/or 9.4(f) shall  not have been fulfilled but  all
    other  conditions to the Closing  shall be fulfilled or  shall be capable of
    being fulfilled, then the Initial Termination Date shall be extended to  May
    10, 1998;
 
        (c) by any party hereto, by written notice to the other parties, if
 
           (i)  the WPL Shareholders' Approval shall not have been obtained at a
       duly held WPL Special Meeting, including any adjournments thereof, or
 
           (ii) the IES Shareholders' Approval shall not have been obtained at a
       duly held IES Special Meeting, including any adjournments thereof, or
 
          (iii) the  Interstate  Shareholders'  Approval  shall  not  have  been
       obtained  at  a  duly  held  Interstate  Special  Meeting,  including any
       adjournments thereof;
 
        (d) by any party  hereto, if any  state or Federal  law, order, rule  or
    regulation  is adopted or issued, which has  the effect, as supported by the
    written opinion of outside counsel for such party,
 
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<PAGE>
    of prohibiting the Merger (including either  or both the IES Merger and  the
    Interstate  Merger),  or  by any  party  hereto  if any  court  of competent
    jurisdiction in the United States or  any State shall have issued an  order,
    judgment   or  decree   permanently  restraining,   enjoining  or  otherwise
    prohibiting the Merger  (including either  or both  the IES  Merger and  the
    Interstate  Merger), and  such order, judgment  or decree  shall have become
    final and nonappealable;
 
        (e) by IES, upon two days' prior notice to WPL and Interstate, if, as  a
    result  of a tender offer by a party  other than WPL or Interstate or any of
    their respective Affiliates or any written offer or proposal with respect to
    a merger,  sale  of a  material  portion of  its  assets or  other  business
    combination  (each, a "BUSINESS  COMBINATION") by a party  other than WPL or
    Interstate or any of their respective Affiliates, the Board of Directors  of
    IES determines in good faith that its fiduciary obligations under applicable
    law  require that such  tender offer or  other written offer  or proposal be
    accepted; PROVIDED, HOWEVER, that
 
           (i) The  Board of  Directors of  IES  shall have  been advised  in  a
       written  opinion  of  outside  counsel  that  notwithstanding  a  binding
       commitment to consummate  an agreement  of the nature  of this  Agreement
       entered  into in the proper exercise  of its applicable fiduciary duties,
       and notwithstanding  all concessions  which  may be  offered by  WPL  and
       Interstate  in negotiations entered  into pursuant to  CLAUSE (ii) below,
       such fiduciary  duties would  require the  directors to  reconsider  such
       commitment  as a result  of such tender  offer or other  written offer or
       proposal; and
 
           (ii) prior to any  such termination, IES shall,  and shall cause  its
       respective  financial  and  legal  advisors to,  negotiate  with  WPL and
       Interstate to make such adjustments in  the terms and conditions of  this
       Agreement   as  would  enable  IES   to  proceed  with  the  transactions
       contemplated herein on such adjusted terms;
 
        (f) by Interstate, upon two days' prior notice to WPL and IES, if, as  a
    result  of a tender offer by  a party other than WPL  or IES or any of their
    respective Affiliates or  any written offer  or proposal with  respect to  a
    Business  Combination  by a  party other  than WPL  or IES  or any  of their
    respective Affiliates, the  Board of Directors  of Interstate determines  in
    good  faith that its fiduciary obligations under applicable law require that
    such tender offer or other written offer or proposal be accepted;  PROVIDED,
    HOWEVER, that
 
           (i) the Board of Directors of Interstate shall have been advised in a
       written  opinion  of  outside  counsel  that  notwithstanding  a  binding
       commitment to consummate  an agreement  of the nature  of this  Agreement
       entered  into in the proper exercise  of its applicable fiduciary duties,
       and notwithstanding all concessions which may  be offered by WPL and  IES
       in  negotiations  entered  into  pursuant  to  CLAUSE  (ii)  below,  such
       fiduciary  duties  would  require   the  directors  to  reconsider   such
       commitment  as a result  of such tender  offer or other  written offer or
       proposal; and
 
           (ii) prior to any such termination, Interstate shall, and shall cause
       its respective financial and  legal advisors to,  negotiate with WPL  and
       IES  to  make  such  adjustments  in the  terms  and  conditions  of this
       Agreement as would  enable Interstate  to proceed  with the  transactions
       contemplated herein on such adjusted terms;
 
        (g)  by WPL, upon two days' prior notice to IES and Interstate, if, as a
    result of a tender offer by a party  other than IES or Interstate or any  of
    their respective Affiliates or any written offer or proposal with respect to
    a  Business Combination by  a party other  than IES or  Interstate or any of
    their respective Affiliates,  the Board  of Directors of  WPL determines  in
    good  faith that its fiduciary obligations under applicable law require that
    such tender offer or other written offer or proposal be accepted;  PROVIDED,
    HOWEVER, that
 
           (i)  the  Board of  Directors of  WPL  shall have  been advised  in a
       written  opinion  of  outside  counsel  that  notwithstanding  a  binding
       commitment  to consummate  an agreement of  the nature  of this Agreement
       entered  into  in  the  proper  exercise  of  its  applicable   fiduciary
 
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<PAGE>
       duties,  and notwithstanding all concessions which  may be offered by IES
       and Interstate  in  negotiations entered  into  pursuant to  CLAUSE  (ii)
       below,  such fiduciary duties  would require the  directors to reconsider
       such commitment as a result of  such tender offer or other written  offer
       or proposal; and
 
           (ii)  prior to any  such termination, WPL shall,  and shall cause its
       respective financial  and  legal  advisors to,  negotiate  with  IES  and
       Interstate  to make such adjustments in  the terms and conditions of this
       Agreement  as  would  enable  WPL   to  proceed  with  the   transactions
       contemplated herein on such adjusted terms;
 
        (h) by IES, by written notice to WPL and Interstate, if
 
           (i)  there exists any  breach or breaches  of the representations and
       warranties of WPL or Interstate made herein or in any of the Stock Option
       Agreements pursuant to  which either  of them  is a  grantor of  options,
       which  breaches, individually  or in  the aggregate  have or,  insofar as
       reasonably can be foreseen, would have, a WPL Material Adverse Effect  or
       an  Interstate Material Adverse Effect, and  such breaches shall not have
       been remedied within 20 days after  receipt by WPL or Interstate, as  the
       case may be, of notice in writing from IES, specifying the nature of such
       breaches and requesting that they be remedied;
 
           (ii)  WPL or  Interstate (and/or its  appropriate Subsidiaries) shall
       not have  performed  and  complied  with  its  agreements  and  covenants
       contained  in SECTIONS 7.3  and 7.4 or  shall have failed  to perform and
       comply with,  in  all  material  respects,  their  other  agreements  and
       covenants hereunder or under the Stock Option Agreements and such failure
       to  perform or comply shall  not have been remedied  within 20 days after
       receipt by WPL or Interstate,  as the case may  be, of notice in  writing
       from IES, specifying the nature of such failure and requesting that it be
       remedied; or
 
          (iii)  the Board  of Directors of  WPL or Interstate  or any committee
       thereof:
 
               (A) shall withdraw  or modify in  any manner adverse  to IES  its
           approval  or recommendation of  this Agreement, or  the IES Merger or
           the Interstate Merger,
 
               (B) shall fail to reaffirm  such approval or recommendation  upon
           IES's request,
 
               (C) shall approve or recommend any Business Combination involving
           WPL  or Interstate other than the Merger involving WPL and Interstate
           or any tender offer for shares of capital stock of WPL or Interstate,
           in each case, by or  involving a party other than  IES or any of  its
           Affiliates or
 
               (D)  shall resolve to take any of the actions specified in CLAUSE
           (A), (B) OR (C);
 
        (i) by Interstate, by written notice to WPL and IES, if
 
           (i) there exists any  breach or breaches  of the representations  and
       warranties  of  WPL or  IES made  herein or  in any  of the  Stock Option
       Agreements pursuant to  which either  of them  is a  grantor of  options,
       which  breaches, individually  or in  the aggregate  have, or  insofar as
       reasonably can be foreseen, would have, a WPL Material Adverse Effect  or
       an  IES Material  Adverse Effect, and  such breaches shall  not have been
       remedied within 20 days after receipt by WPL or IES, as the case may  be,
       of  notice  in writing  from Interstate,  specifying  the nature  of such
       breaches and requesting that they be remedied;
 
           (ii) WPL or IES (and/or its appropriate Subsidiaries) shall not  have
       performed  and complied  with its  agreements and  covenants contained in
       SECTIONS 7.3 and 7.4 or shall have failed to perform and comply with,  in
       all  material respects, its  other agreements and  covenants hereunder or
       under the Stock Option Agreements and  such failure to perform or  comply
       shall  not have been remedied within 20 days after receipt by WPL or IES,
       as the case may be, of notice in writing from Interstate, specifying  the
       nature of such failure and requesting that it be remedied; or
 
                                      A-72
<PAGE>
          (iii) the Board of Directors of WPL or IES or any committee thereof:
 
               (A)  shall withdraw or modify in any manner adverse to Interstate
           its approval or recommendation of  this Agreement, the IES Merger  or
           the Interstate Merger,
 
               (B)  shall fail to reaffirm  such approval or recommendation upon
           Interstate's request,
 
               (C) shall approve or recommend any Business Combination involving
           WPL or IES other than the Merger involving WPL and IES or any  tender
           offer  for shares of capital stock of WPL or IES, in each case, by or
           involving a party other than Interstate or any of its Affiliates or
 
               (D) shall resolve to take any of the actions specified in  CLAUSE
           (A), (B) or (C); or
 
        (j)  by WPL, by written notice to Interstate and IES, if
 
           (i)  there exists any  breach or breaches  of the representations and
       warranties of Interstate or IES made herein or in any of the Stock Option
       Agreements pursuant to  which either  of them  is a  grantor of  options,
       which  breaches, individually  or in  the aggregate  have or,  insofar as
       reasonably can be  foreseen, would have,  an Interstate Material  Adverse
       Effect  or an  IES Material Adverse  Effect, and such  breaches shall not
       have been remedied within 20 days after receipt by Interstate or IES,  as
       the  case may be, of notice in writing from WPL, specifying the nature of
       such breaches and requesting that they be remedied;
 
           (ii) Interstate or  IES (and/or its  appropriate Subsidiaries)  shall
       not  have  performed  and  complied  with  its  agreements  and covenants
       contained in SECTIONS  7.3 and 7.4  or shall have  failed to perform  and
       comply with, in all material respects, its other agreements and covenants
       hereunder  or  under the  Stock Option  Agreements,  and such  failure to
       perform or  comply shall  not have  been remedied  within 20  days  after
       receipt  by Interstate or IES,  as the case may  be, of notice in writing
       from WPL, specifying the nature of such failure and requesting that it be
       remedied; and
 
          (iii) the Board  of Directors of  Interstate or IES  or any  committee
       thereof:
 
               (A)  shall withdraw  or modify in  any manner adverse  to WPL its
           approval or recommendation of  this Agreement, or  the IES Merger  or
           the Interstate Merger,
 
               (B)  shall fail to reaffirm  such approval or recommendation upon
           WPL's request,
 
               (C) shall approve or recommend any Business Combination involving
           Interstate or IES other than the Merger involving Interstate and  IES
           or  any tender offer for the shares of capital stock of Interstate or
           IES, in each case by  or involving a party other  than WPL or any  of
           its Affiliates or
 
               (D)  shall resolve to take any of the actions specified in CLAUSE
           (A), (B) or (C).
 
    Section 10.2   EFFECT OF TERMINATION.   Subject to  SECTION 11.1(b), in  the
event  of termination of  this Agreement by  WPL, IES or  Interstate pursuant to
SECTION 10.1 there  shall be  no liability  on the part  of either  WPL, IES  or
Interstate  or  their respective  officers or  directors hereunder,  except that
SECTION 8.1(b), SECTION 8.17, SECTION 10.3, SECTION 11.2 and SECTION 11.8  shall
survive the termination.
 
    Section 10.3  TERMINATION FEE; EXPENSES.
 
        (a)   TERMINATION FEE  UPON BREACH OR  WITHDRAWAL OF APPROVAL.   If this
    Agreement is  terminated at  such  time that  this Agreement  is  terminable
    pursuant  to one or two  (but not three) of  (x) SECTION 10.1(h)(i) or (ii),
    (y) SECTION 10.1(i)(i) or (ii) or (z) SECTION 10.1(j)(i) or (ii), then:
 
           (i) each  breaching party  shall  promptly (but  no later  than  five
       business  days after  receipt of notice  from the  non-breaching party or
       parties (other than Acquisition and New
 
                                      A-73
<PAGE>
       Interstate)) pay  to the  non-breaching  party or  parties in  cash  such
       breaching party's Participation Percentage (as hereinafter defined) of an
       amount  equal to all documented  out-of-pocket expenses and fees incurred
       by the  non-breaching party  or parties  (including, without  limitation,
       fees  and expenses  payable to  all legal,  accounting, financial, public
       relations and other professional advisors  arising out of, in  connection
       with  or related to  the Merger or the  transactions contemplated by this
       Agreement) not  in excess  of  $5 million  for any  non-breaching  party;
       PROVIDED,  HOWEVER, that, if this Agreement is terminated by a party as a
       result of a willful breach by  any other party, each non-breaching  party
       may pursue any remedies available to it at law or in equity and shall, in
       addition  to its documented out-of-pocket  expenses and fees (which shall
       be paid as specified above and shall not be limited to $5 million for any
       non-breaching party), be  entitled to retain  such additional amounts  as
       such  non-breaching party may be entitled to receive at law or in equity;
       and
 
           (ii) if
 
               (A) at the  time of a  breaching party's willful  breach of  this
           Agreement,  there  shall have  been a  third  party tender  offer for
           shares of,  or a  third party  offer or  proposal with  respect to  a
           Business  Combination involving, such party  or any of its Affiliates
           which at the time of such termination shall not have been rejected by
           such party  and its  board of  directors or  withdrawn by  the  third
           party, and
 
               (B)  within  two  and  one-half years  of  any  termination  by a
           non-breaching party,  the breaching  party  or an  Affiliate  thereof
           becomes  a Subsidiary of such offeror or a Subsidiary of an Affiliate
           of  such  offeror  or  accepts  a  written  offer  to  consummate  or
           consummates  a Business Combination with such offeror or an Affiliate
           thereof,
 
    then such breaching party  (jointly and severally  with its Affiliates),  at
    the  closing (and  as a  condition to the  closing) of  such breaching party
    becoming such a Subsidiary or of such Business Combination, will pay to each
    non-breaching party (other than Acquisition and New Interstate) in cash such
    non-breaching party's Participation  Percentage of  an additional  aggregate
    fee equal to $25 million, if WPL is the breaching party, $25 million, if IES
    is  the breaching  party, or $12.5  million, if Interstate  is the breaching
    party.
 
        (b)  ADDITIONAL TERMINATION FEE.  If
 
           (i) this Agreement
 
               (A) is terminated by any  party pursuant to SECTION 10.1(e),  (f)
           or (g),
 
               (B)  is terminated following a failure of the shareholders of any
           one of  the  necessary  parties  to  grant  the  necessary  approvals
           described in SECTION 4.13, SECTION 5.13 and SECTION 6.13 or
 
               (C)  is terminated as a result  of any party's material breach of
           SECTION 8.4, and
 
           (ii) at the time of such termination or prior to the meeting of  such
       party's shareholders there shall have been a third-party tender offer for
       shares  of, or a third-party offer or proposal with respect to a Business
       Combination involving, such party or any  of its Affiliates which at  the
       time  of such termination or of  the meeting of such party's shareholders
       shall not have been (A) rejected by such party and its board of directors
       or (B) withdrawn by the third party, and
 
          (iii) within two and one-half years of any such termination  described
       in  clause  (i)  above, a  Target  Party  (as defined  herein)  becomes a
       Subsidiary of  such offeror  or  a Subsidiary  of  an Affiliate  of  such
       offeror  or  accepts  a  written offer  to  consummate  or  consummates a
       Business Combination with such offeror or an Affiliate thereof,
 
    then such Target Party (jointly and  severally with its Affiliates), at  the
    closing  (and as a condition  to the closing) of  such Target Party becoming
    such a Subsidiary or of such Business Combination,
 
                                      A-74
<PAGE>
    will pay to each other party (other than Acquisition and New Interstate)  in
    cash such other party's Participation Percentage of an aggregate termination
    fee equal to $25 million, if WPL is the Target Party, $25 million, if IES is
    the Target Party, or $12.5 million, if Interstate is the Target Party, plus,
    in  each case,  the documented out-of-pocket  fees and  expenses incurred by
    each such  non-breaching  party  (including, without  limitation,  fees  and
    expenses  payable to all legal,  accounting, financial, public relations and
    other professional advisors arising out of, in connection with or related to
    the Merger or the transactions contemplated by this Agreement).
 
        (c)  SECOND  TERMINATION FEE.   If  this Agreement  is terminated  under
    circumstances  that give rise to the payment  of any fee pursuant to SECTION
    10.3(b) by  any  party, and  thereafter,  within  nine (9)  months  of  such
    termination,  either of the parties that was  not a Target Party at the time
    of such termination becomes a Target Party (a "SECOND TARGET PARTY") of  the
    same  entity, or an Affiliate thereof, that caused the original Target Party
    to become such, then  such Second Target Party  (jointly and severally  with
    its Affiliates), upon the signing of a definitive agreement relating to such
    a  Business Combination,  or, if  no such agreement  is signed,  then at the
    closing (and as  a condition  to the closing)  of such  Second Target  Party
    becoming  such a Subsidiary or of such Business Combination, will pay to the
    remaining party (other than Acquisition and New Interstate) that is  neither
    a Target Party nor a Second Target Party (a "NON-TARGET PARTY")
 
           (i)  a termination fee  in cash equal  to $25 million,  if WPL is the
       Second Target Party, $25 million, if  IES is the Second Target Party,  or
       $12.5  million, if Interstate  is the Second Target  Party, plus, in each
       case, any additional documented out-of-pocket fees and expenses  incurred
       by the Non-Target Party (including, without limitation, fees and expenses
       payable  to all legal, accounting,  financial, public relations and other
       professional advisors arising out  of, in connection  with or related  to
       the Merger or the transactions contemplated by this Agreement); and
 
           (ii)  the full amount of any termination  fee paid to it by the first
       Target Party.
 
        (d)  EXPENSES.  The parties agree that the agreements contained in  this
    SECTION  10.3 are an  integral part of the  transactions contemplated by the
    Agreement and constitute liquidated damages and not a penalty. If one  party
    fails  to  promptly  pay to  any  other  party any  fee  due  hereunder, the
    defaulting party shall pay the costs and expenses (including legal fees  and
    expenses) in connection with any action, including the filing of any lawsuit
    or  other legal action, taken to  collect payment, together with interest on
    the amount  of  any unpaid  fee  at the  publicly  announced prime  rate  of
    Citibank, N.A. from the date such fee was required to be paid.
 
        (e)  LIMITATION ON TERMINATION FEES.  Notwithstanding anything herein to
    the contrary,
 
           (i)  the aggregate  amount payable by  WPL and its  Affiliates to IES
       and/or Interstate pursuant  to SECTION 10.3(a),  SECTION 10.3(b) and  the
       terms  of the WPL/IES Stock Option Agreement and the WPL/Interstate Stock
       Option Agreement shall not exceed $40 million,
 
           (ii) the aggregate amount payable by IES and its Affiliates  pursuant
       to  SECTION 10.3(a), SECTION  10.3(b) and the terms  of the IES/WPL Stock
       Option Agreement and the IES/Interstate Stock Option Agreement shall  not
       exceed $40 million, and
 
          (iii)  the aggregate amount  payable by Interstate  and its Affiliates
       under  SECTION   10.3(a),  SECTION   10.3(b)  and   the  terms   of   the
       Interstate/WPL Stock Option Agreement and the Interstate/IES Stock Option
       Agreement shall not exceed $20 million
 
    (exclusive,  in each  case, of reimbursement  for fees  and expenses payable
    pursuant to this SECTION  10.3). For purposes of  this SECTION 10.3(d),  the
    amount payable pursuant to the terms of the Stock Option Agreements shall be
    the  amount paid pursuant  to SECTION 5 and/or  SECTION 8(a)(i) and 8(a)(ii)
    thereof.
 
                                      A-75
<PAGE>
        (f)  CERTAIN DEFINITIONS.
 
               (i)     PARTICIPATION   PERCENTAGE.     A  party's  participation
           percentage ("PARTICIPATION PERCENTAGE") shall be one hundred  percent
           (100%)  if only one party  is required to pay  or entitled to receive
           its Participation Percentage  pursuant to the  terms of this  SECTION
           10.3. If two parties are required to pay or entitled to receive their
           respective  Participation  Percentages,  each  party's  Participation
           Percentage shall equal  a fraction (expressed  as a percentage),  the
           numerator  of which shall be,  in the case of  IES or Interstate, the
           number of shares of  WPL Common Stock which  would be issuable (on  a
           fully diluted basis) to such party's shareholders, or, in the case of
           WPL,  the number of  shares of WPL  Common Stock (on  a fully diluted
           basis) that would  have been  retained by its  shareholders, had  the
           Effective  Time occurred at the time this Agreement is terminated and
           the denominator of which shall be, the aggregate number of shares  of
           WPL  Common Stock that would be issuable to or retained by (in either
           case on a fully  diluted basis) the shareholders  of the two  parties
           required   to  pay   or  entitled  to   receive  their  Participation
           Percentages, had  the  Effective  time  occurred  at  the  time  this
           Agreement is terminated.
 
               (ii)   TARGET PARTY.   The term "TARGET PARTY"  shall mean any of
           WPL, IES or Interstate, or  their respective Affiliates, that is  the
           subject  of a  tender offer  or offer or  proposal with  respect to a
           Business Combination.
 
    Section 10.4  AMENDMENT.
 
        (a) This Agreement  may be  amended by the  Boards of  Directors of  the
    parties  hereto,  at  any  time  before  or  after  approval  hereof  by the
    shareholders of WPL, IES and Interstate and prior to the Effective Time, but
    after such approvals, no such amendment shall
 
           (i) alter or change the  amount or kind of  shares, rights or any  of
       the proceedings of the treatment of shares under Article II,
 
           (ii)  alter  or  change  any  of the  terms  and  conditions  of this
       Agreement if  any  of  the  alterations  or  changes,  alone  or  in  the
       aggregate,  would materially  adversely affect  the rights  of holders of
       WPL, IES and Interstate Common Stock, or
 
          (iii)  alter  or  change  any   term  of  the  Restated  Articles   of
       Incorporation  of WPL, IES or Interstate  as approved by the shareholders
       of WPL,  IES  and Interstate,  respectively,  except for  alterations  or
       changes  that could otherwise be adopted by the Board of Directors of the
       Company,  without  the   further  approval  of   such  shareholders,   as
       applicable.
 
        (b) This Agreement may not be amended except by an instrument in writing
    signed on behalf of each of the parties hereto.
 
    Section 10.5  WAIVER.
 
        (a) At any time prior to the Effective Time, the parties hereto may
 
           (i)  extend the time for the performance of any of the obligations or
       other acts of the other parties hereto,
 
           (ii) waive  any inaccuracies  in the  representations and  warranties
       contained herein or in any document delivered pursuant hereto and
 
          (iii)  waive  compliance  with  any of  the  agreements  or conditions
       contained herein, to the extent permitted by applicable law.
 
        (b) Any agreement on the part of a party hereto to any such extension or
    waiver shall be valid  if set forth  in an instrument  in writing signed  on
    behalf of such party.
 
                                      A-76
<PAGE>
                                   ARTICLE XI
                               GENERAL PROVISIONS
 
    Section 11.1  NON-SURVIVAL; EFFECT OF REPRESENTATIONS AND WARRANTIES.
 
        (a)  All representations,  warranties and  agreements in  this Agreement
    shall not survive the Merger, except as otherwise provided in this Agreement
    and except for the agreements contained in this SECTION 11.1 and in  Article
    II,   SECTION  8.5  (Director  and  Officer  Indemnification),  SECTION  8.9
    (Employee Agreements and Workforce Matters), SECTION 8.10 (Employee  Benefit
    Plans),  SECTION 8.11  (STOCK OPTION  AND OTHER  STOCK PLANS),  SECTION 8.13
    (Company Board of Directors), SECTION 8.14 (Company Officers), SECTION  8.15
    (Employment  Contracts), SECTION 8.16 (Post-Merger Operations), SECTION 8.17
    (Expenses), SECTION 11.2 (Brokers) and SECTION 11.7 (Parties in Interest).
 
        (b) No party  may assert  a claim for  breach of  any representation  or
    warranty   contained  in  this   Agreement  (whether  by   direct  claim  or
    counterclaim) except in  connection with the  termination of this  Agreement
    pursuant  to SECTION  10.1(h)(i), SECTION 10.1(i)(i),  or SECTION 10.1(j)(i)
    (or pursuant to  any other subsection  of SECTION 10.1,  if the  terminating
    party  would  have been  entitled to  terminate  this Agreement  pursuant to
    SECTION 10.1(h)(i), SECTION 10.1(i)(i) or SECTION 10.1(j)(i)).
 
    SECTION 11.2  BROKERS.
 
        (a) WPL represents  and warrants  that, except for  Merrill, whose  fees
    have  been disclosed  to IES  and Interstate  prior to  the date  hereof, no
    broker, finder or investment banker  is entitled to any brokerage,  finder's
    or   other  fee  or  commission  in  connection  with  the  Merger,  or  the
    transactions contemplated by this Agreement based upon arrangements made  by
    or on behalf of WPL.
 
        (b) IES represents and warrants that, except for Morgan, whose fees have
    been  disclosed to WPL and  Interstate prior to the  date hereof, no broker,
    finder or investment banker is entitled to any brokerage, finder's or  other
    fee  or commission  in connection  with the  IES Merger  or the transactions
    contemplated by this Agreement based upon arrangements made by or on  behalf
    of IES.
 
        (c)  Interstate represents and warrants  that, except for Salomon, whose
    fees have been disclosed to WPL and IES prior to the date hereof, no broker,
    finder or investment banker is entitled to any brokerage, finder's or  other
    fee   or  commission  in  connection  with  the  Interstate  Merger  or  the
    transactions contemplated by this Agreement based upon arrangements made  by
    or on behalf of Interstate.
 
    Section 11.3  NOTICES.  All notices and other communications hereunder shall
be  in writing and shall be deemed  given if (i) delivered personally, (ii) sent
by reputable overnight courier service,
 
                                      A-77
<PAGE>
(iii) telecopied (which is confirmed), or  (iv) five days after being mailed  by
registered  or certified mail  (return receipt requested) to  the parties at the
following addresses (or at such other address for a party as shall be  specified
by like notice):
 
<TABLE>
<S>        <C>                 <C>
(a)        If to WPL, to:      WPL Holdings, Inc.
                               222 West Washington Avenue
                               P.O. Box 2568
                               Madison, WI 53701-2568
           Attention:          Erroll B. Davis, Jr.
                               PRESIDENT AND CHIEF EXECUTIVE OFFICER
           Telephone:          (608) 252-3137
           Telecopy:           (608) 252-5059
           with a copy to:     Foley & Lardner
                               777 East Wisconsin Avenue
                               Milwaukee, WI 53202-5367
           Attention:          Benjamin F. Garmer, III, Esq.
           Telephone:          (414) 297-5675
           Telecopy:           (414) 297-4900
 
(b)        If to IES, to:      IES Industries Inc.
                               IES Tower
                               200 First Street S.E.
                               Cedar Rapids, IO 52401
           Attention:          Stephen W. Southwick
                               VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
           Telephone:          (319) 398-8147
           Telecopy:           (319) 398-4204
           with a copy to:     Winthrop, Stimson, Putnam & Roberts
                               One Battery Park Plaza
                               New York, New York 10004-1490
           Attention:          Stephen R. Rusmisel, Esq.
           Telephone:          (212) 858-1442
           Telecopy:           (212) 858-1500
 
(c)        If to Interstate,   Interstate Power Company
           to:                 1000 Main Street
                               P.O. Box 769
                               Dubuque, IO 52004-0789
           Attention:          Wayne H. Stoppelmoor
                               CHAIRMAN OF THE BOARD
           Telephone:          (319) 557-2200
           Telecopy:           (319) 557-2202
           with a copy to:     Milbank, Tweed, Hadley & McCloy
                               1 Chase Manhattan Plaza
                               New York, New York 10005-1413
           Attention:          John T. O'Connor, Esq.
           Telephone:          (212) 530-5548
           Telecopy:           (212) 530-0283
</TABLE>
 
                                      A-78
<PAGE>
    Section  11.4  MISCELLANEOUS.   This Agreement  (including the documents and
instruments referred to herein)
 
        (a) constitutes  the entire  agreement and  supersedes all  other  prior
    agreements  and understandings, both written and oral, among the parties, or
    any of  them, with  respect to  the  subject matter  hereof other  than  the
    Confidentiality Agreement and the Stock Option Agreements;
 
        (b) shall not be assigned by operation of law or otherwise; and
 
        (c)  shall be governed by  and construed in accordance  with the laws of
    the State of Delaware  applicable to contracts executed  in and to be  fully
    performed in such State, without giving effect to its conflicts of law rules
    or principles or to any requirement as to jurisdiction or service of process
    contained in Section 2708 of Title 6 of the Delaware Code, and except to the
    extent  the  provisions  of  this  Agreement  (including  the  documents  or
    instruments referred to herein)  are expressly governed  by or derive  their
    authority from the WBCL, IBCA or the DGCL.
 
    Section 11.5  INTERPRETATION.  When a reference is made in this Agreement to
Sections  or Exhibits, such reference  shall be to a  Section or Exhibit of this
Agreement, respectively, unless otherwise indicated.  The table of contents  and
headings  contained in this Agreement are  for reference purposes only and shall
not affect in any way the meaning or interpretation of this Agreement.  Whenever
the  words "INCLUDE," "INCLUDES" or "INCLUDING" are used in this Agreement, they
shall be deemed to be
followed by the words "WITHOUT LIMITATION."
 
    SECTION 11.6  COUNTERPARTS; EFFECT.   This Agreement may be executed in  one
or  more counterparts, each of which shall be  deemed to be an original, but all
of which shall constitute one and the same agreement.
 
    Section 11.7  PARTIES IN INTEREST.
 
        (a) A majority of the IES Directors (or their successors) serving on the
    Board of Directors  of the  Company who are  designated by  IES pursuant  to
    SECTION  8.13 (Company Board  of Directors) shall be  entitled to enforce or
    waive compliance with the  provisions of SECTION 8.13  during the time  such
    provisions  are,  by  their specific  terms,  applicable and  shall  also be
    entitled during the three-year period commencing at the Effective Time  (the
    "THREE-YEAR  PERIOD")  to enforce  the provisions  of SECTION  8.9 (Employee
    Agreements and Workforce Matters),  SECTION 8.10 (Employee Benefits  Plans),
    SECTION  8.11 (Stock Option and Other Stock Plans), SECTION 8.14(a) (Company
    Officers), SECTION 8.15 (Employment Contracts)  and SECTION 8.16(b) AND  (d)
    (Post-Merger  Operations), and the agreements  referred to in SCHEDULES 4.10
    (Employee Matters; ERISA),  5.10 (Employee Matters;  ERISA), 6.10  (Employee
    Matters; ERISA) and 7.10 (Compensation Benefits), in each instance on behalf
    of the IES officers, directors and employees, as the case may be;
 
        (b) A majority of the WPL Directors (or their successors) serving on the
    Board  of Directors  of the  Company who are  designated by  WPL pursuant to
    SECTION 8.13  shall be  entitled to  enforce or  waive compliance  with  the
    provisions  of SECTION  8.13 during the  time such provisions  are, by their
    specific terms, applicable and shall  also be entitled during the  five-year
    period  following the  Effective Time to  enforce the  provisions of SECTION
    8.14(b) and (h)  and SECTION  8.16(a) and  during the  Three-Year Period  to
    enforce  the  provisions  of SECTION  8.9,  SECTION 8.10,  SECTION  8.11 and
    SECTION 8.15, and the agreements referred  to in SCHEDULES 4.10, 5.10,  6.10
    and  7.10,  in  each  instance  on behalf  of  WPL  officers,  directors and
    employees, as the case may be; and
 
        (c) A majority of the Interstate Directors (or their successors) serving
    on the Board of  Directors of the Company  who are designated by  Interstate
    pursuant  to SECTION 8.13  shall be entitled to  enforce or waive compliance
    with the provisions of SECTION 8.13 during the time such provisions are,  by
    their  specific  terms, applicable  and shall  also  be entitled  during the
    Three-Year
 
                                      A-79
<PAGE>
    Period to enforce the provisions of SECTION 8.9, SECTION 8.10, SECTION 8.11,
    SECTION  8.14(c),  SECTION  8.15  and  SECTION  8.16(b)  and  (d),  and  the
    agreements  referred  to in  SCHEDULES 4.10,  5.10, 6.10  and 7.10,  in each
    instance on behalf of the  Interstate officers, directors and employees,  as
    the case may be.
 
    Section  11.8  BINDING EFFECT; BENEFITS.   This Agreement shall inure to the
benefit of  and  be  binding  upon  the  parties  hereto  and  their  respective
successors  and assigns; except as provided  in SECTION 8.5(e) and SECTION 11.7,
nothing in this  Agreement, express or  implied, shall confer  upon any  person,
other  than the parties hereto and  their respective successors and assigns, any
rights, remedies,  obligations  or  liabilities  under  or  by  reason  of  this
Agreement.
 
    Section  11.9  WAIVER OF JURY TRIAL AND CERTAIN DAMAGES.  EACH PARTY TO THIS
AGREEMENT WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW,
 
        (a) ANY RIGHT IT MAY HAVE TO A  TRIAL BY JURY IN RESPECT OF ANY  ACTION,
    SUIT OR PROCEEDING ARISING OUT OF OR RELATING TO THIS AGREEMENT, AND
 
        (b) WITHOUT LIMITATION TO SECTION 10.3, ANY RIGHT IT MAY HAVE TO RECEIVE
    DAMAGES  FROM  ANY OTHER  PARTY BASED  ON  ANY THEORY  OF LIABILITY  FOR ANY
    SPECIAL,  INDIRECT,  CONSEQUENTIAL  (INCLUDING  LOST  PROFITS)  OR  PUNITIVE
    DAMAGES.
 
    Section 11.10  ENFORCEMENT.  The parties agree that irreparable damage would
occur  in  the event  that  any of  the provisions  of  this Agreement  were not
performed in accordance with their specific terms or were otherwise breached. It
is accordingly agreed  that the parties  shall be entitled  to an injunction  or
injunctions  to prevent breaches  of this Agreement  and to enforce specifically
the terms and provisions hereof, this being  in addition to any other remedy  to
which they are entitled at law or in equity.
 
                                      A-80
<PAGE>
    IN  WITNESS WHEREOF,  WPL, IES,  Interstate, Acquisition  and New Interstate
have caused this Agreement to be  signed by their respective officers  thereunto
duly authorized as of the date first written above.
 
<TABLE>
<C>                                            <S>
                                               WPL HOLDINGS, INC.
                   Attest:
 
      By:         /s/ EDWARD M. GLEASON        By:         /s/ ERROLL B. DAVIS, JR.
     --------------------------------------    ------------------------------------------
                Edward M. Gleason              Name: Erroll B. Davis, Jr.
               CORPORATE SECRETARY             Title: PRESIDENT AND CHIEF
                                               EXECUTIVE OFFICER
 
                                               IES INDUSTRIES INC.
                   Attest:
 
     By:        /s/ STEPHEN W. SOUTHWICK       By:               /s/ LEE LIU
     --------------------------------------    ------------------------------------------
              Stephen W. Southwick             Name: Lee Liu
          SECRETARY AND GENERAL COUNSEL        Title: CHAIRMAN OF THE BOARD, PRESIDENT
                                               AND CHIEF EXECUTIVE OFFICER
 
                                               INTERSTATE POWER COMPANY
                                               (a Delaware corporation)
                   Attest:
 
      By:         /s/ JOSEPH C. MCGOWAN        By:        /s/ WAYNE H. STOPPELMOOR
     --------------------------------------    ------------------------------------------
                Joseph C. McGowan              Name: Wayne H. Stoppelmoor
             SECRETARY AND TREASURER           Title: CHAIRMAN OF THE BOARD, PRESIDENT
                                               AND CHIEF EXECUTIVE OFFICER
 
                                               WPLH ACQUISITION CO.
                   Attest:
 
      By:         /s/ EDWARD M. GLEASON        By:         /s/ ERROLL B. DAVIS, JR.
     --------------------------------------    ------------------------------------------
                Edward M. Gleason              Name: Erroll B. Davis, Jr.
                    SECRETARY                  Title: PRESIDENT
 
                                               INTERSTATE POWER COMPANY
                                               (a Wisconsin corporation)
                   Attest:
 
      By:         /s/ JOSEPH C. MCGOWAN        By:           /s/ MICHAEL R. CHASE
     --------------------------------------    ------------------------------------------
                Joseph C. McGowan              Name: Michael R. Chase
                    SECRETARY                  Title: PRESIDENT
</TABLE>
 
                                      A-81
<PAGE>
                                                 EXHIBIT 1.3 TO MERGER AGREEMENT
 
                                 PLAN OF MERGER
 
    THIS  PLAN OF MERGER, dated as of              , 199 (the "Plan of Merger"),
is entered into by and between WPL Holdings, Inc., a Wisconsin corporation ("WPL
Holdings"), and IES Industries Inc., an  Iowa corporation ("IES"). This Plan  of
Merger  is being entered into pursuant to an Agreement and Plan of Merger, dated
as of November 10, 1995, as amended  (the "Merger Agreement"), by and among  WPL
Holdings,  IES, Interstate Power Company, a Delaware corporation ("Interstate"),
WPLH Acquisition Co., a Wisconsin corporation  and a wholly owned subsidiary  of
WPL Holdings, and Interstate Power Company, a Wisconsin corporation and a wholly
owned  subsidiary  of  Interstate.  The Merger  Agreement,  among  other things,
provides for the merger of IES with and into WPL Holdings (the "Merger").
 
    NOW, THEREFORE, in consideration of  the premises and the agreements  herein
contained, the parties hereto, intending to be legally bound hereby, agree to as
follows:
 
                                   ARTICLE I
                                   THE MERGER
 
    1.01.    THE MERGER.   Subject  to the  terms and  conditions of  the Merger
Agreement and  this Plan  of  Merger, IES  shall be  merged  with and  into  WPL
Holdings  in accordance with  and with the  effect as provided  in the Wisconsin
Business Corporation Law (the "WBCL") and the Iowa Business Corporation Act (the
"IBCA").  WPL  Holdings  shall  be  the  surviving  corporation  in  the  Merger
(sometimes  hereafter  referred to  as  the "Surviving  Corporation")  and shall
continue its corporate existence under the  laws of the State of Wisconsin.  The
separate corporate existence of IES shall cease.
 
    1.02.   EFFECTIVE  TIME OF  THE MERGER.   Subject  to the  provisions of the
Merger Agreement and this Plan of  Merger, articles of merger (the "Articles  of
Merger")  shall be  duly prepared and  executed by or  on behalf of  IES and WPL
Holdings and thereafter  delivered to the  Secretary of State  of the States  of
Wisconsin  and Iowa  for filing, as  provided in the  WBCL and the  IBCA, on the
Closing Date  (as defined  in the  Merger Agreement).  The Merger  shall  become
effective  at  the time  specified  in the  Articles  of Merger  filed  with the
Secretary of State of the States of Wisconsin and Iowa (the "Effective Time").
 
    1.03.   RESTATED ARTICLES  OF  INCORPORATION AND  BY-LAWS OF  THE  SURVIVING
CORPORATION.   At the Effective Time, (i) the Restated Articles of Incorporation
of WPL Holdings in effect immediately prior  to the Effective Time shall be  the
Restated  Articles of  Incorporation of  the Surviving  Corporation, except that
Article I of  the Restated Articles  of Incorporation of  WPL Holdings shall  be
amended  in its entirety to provide as  follows: "The name of the corporation is
Interstate Energy Corporation."; and (ii) the By-laws of WPL Holdings in  effect
immediately  prior to the Effective  Time shall be the  By-laws of the Surviving
Corporation.
 
    1.04.   DIRECTORS  AND  OFFICERS  OF THE  SURVIVING  CORPORATION.    At  the
Effective  Time, the  Board of Directors  of the Surviving  Corporation shall be
comprised of  the persons  designated pursuant  to Section  8.13 of  the  Merger
Agreement  and the Chairman and Vice Chairman  of the Board of Directors and the
Chief Executive Officer and President of the Surviving Corporation shall be  the
persons  designated in Section  8.14 (a), (b)  and (c) of  the Merger Agreement.
Except as  otherwise provided  in  Section 8.14  of  the Merger  Agreement,  the
officers  of  WPL Holdings  at  the Effective  Time  shall, from  and  after the
Effective Time,  continue as  the officers  of the  Surviving Corporation  until
their  successors have  been duly  elected or  appointed and  qualified or until
their earlier death, resignation or removal.
 
                                      A-82
<PAGE>
                                   ARTICLE II
                              CONVERSION OF SHARES
 
    2.01.  CANCELLATION AND  CONVERSION OF IES COMMON  STOCK.  At the  Effective
Time,  in  accordance with  the terms  and  conditions set  forth in  the Merger
Agreement, and by virtue of the Merger and without any action on the part of any
holder of shares of Common Stock, no par value, of IES ("IES Common Stock"):
 
        (a)  CANCELLATION OF CERTAIN IES COMMON STOCK.  Each share of IES Common
    Stock that  is owned  by IES  or WPL  Holdings or  any of  their  respective
    subsidiaries  shall be  cancelled and cease  to exist,  and no consideration
    shall be delivered in exchange therefor.
 
        (b)  CONVERSION OF CERTAIN IES COMMON  STOCK.  Each share of IES  Common
    Stock  issued and outstanding immediately prior to the Effective Time (other
    than shares  cancelled  pursuant to  Section  2.01(a) or  shares  for  which
    dissenters'  rights  have  been  exercised under  applicable  law)  shall be
    converted into  the right  to receive  [insert IES  Ratio as  determined  in
    accordance  with  the Merger  Agreement] shares  of  Common Stock,  $.01 par
    value,  of  WPL  Holdings  ("WPL  Holdings  Common  Stock"),  including  the
    associated  rights  to purchase  shares of  WPL  Holdings Common  Stock (the
    "Rights") pursuant to that certain Rights Agreement between WPL Holdings and
    Morgan Shareholder Services Trust Company, as Rights Agent thereunder, dated
    February 22, 1989 (the "Rights Agreement"). Until the Distribution Date  (as
    defined  in the Rights Agreement), all references  in this Plan of Merger to
    the WPL Holdings  Common Stock  shall be  deemed to  include the  associated
    Rights.
 
        (c)   NO FRACTIONAL SHARES.  Notwithstanding any other provision of this
    Plan of  Merger  to the  contrary,  no certificates  or  scrip  representing
    fractional  shares  of WPL  Holdings  Common Stock  shall  be issued  in the
    Merger, and such fractional  shares shall not entitle  the owner thereof  to
    vote as, or to any rights of, a holder of WPL Holdings Common Stock. In lieu
    of  any  such fractional  shares, a  holder  of IES  Common Stock  who would
    otherwise have been entitled  to a fractional share  of WPL Holdings  Common
    Stock  shall  receive a  cash  payment in  an  amount equal  to  the product
    (rounded to  the nearest  cent) of  such fraction  (rounded to  the  nearest
    thousandth)  multiplied by  the average  of the  last reported  sales price,
    regular way, per share of  WPL Holdings Common Stock  on the New York  Stock
    Exchange  ("NYSE") Composite  Tape for  the ten  business days  prior to and
    including the last  business day prior  to the Effective  Time on which  WPL
    Holdings Common Stock was traded on the NYSE, without any interest thereon.
 
    2.02.   WPL HOLDINGS COMMON STOCK.   The shares of WPL Holdings Common Stock
issued and outstanding  immediately prior  to the  Effective Time  shall not  be
affected in any manner by virtue of the Merger.
 
    2.03.   IES PREFERRED  STOCK.  There  are no shares  of Cumulative Preferred
Stock, no par value, of IES issued  and outstanding and there will be no  shares
of  Cumulative Preferred Stock of IES issued and outstanding as of the Effective
Time.
 
                                  ARTICLE III
                            CONDITIONS; TERMINATION
 
    3.01.  CONDITIONS TO THE MERGER.  Consummation of the Merger is  conditional
upon  the fulfillment or waiver of the conditions precedent set forth in Article
IX of the Merger Agreement.
 
    3.02.  TERMINATION.   This Plan of Merger  shall terminate forthwith in  the
event  that the Merger Agreement shall be terminated as therein provided. In the
event of the termination of this Plan of Merger as provided above, this Plan  of
Merger  shall forthwith become void and there  shall be no liability on the part
of any  of  the parties  hereto,  except as  otherwise  provided in  the  Merger
Agreement.
 
                                      A-83
<PAGE>
                                   ARTICLE IV
                               GENERAL PROVISIONS
 
    4.01.   COUNTERPARTS.  This Plan of  Merger may be executed in counterparts,
each of which shall constitute one and the same instrument.
 
    4.02.  HEADINGS.   The  headings in  this Plan  of Merger  are inserted  for
convenience only and shall not constitute a part hereof.
 
    IN WITNESS WHEREOF, the parties hereto have caused this Plan of Merger to be
duly executed as of the date first above written.
 
                                        WPL HOLDINGS, INC.
                                        ("WPL Holdings")
 
                                        By:
                                           -------------------------------------
 
                                        Attest:
                                           -------------------------------------
 
                                        IES INDUSTRIES INC.
                                        ("IES")
 
                                        By:
                                           -------------------------------------
 
                                        Attest:
                                           -------------------------------------
 
                                      A-84
<PAGE>
                                                                         ANNEX B
 
                   OPTION GRANTOR/OPTION HOLDER STOCK OPTION
                         AND TRIGGER PAYMENT AGREEMENT
 
    This STOCK OPTION AGREEMENT, dated as of November 10, 1995 (the "AGREEMENT")
by  and among WPL Holdings, Inc., a  corporation organized under the laws of the
State of Wisconsin ("OPTION GRANTOR" or the "COMPANY") and IES Industries  Inc.,
a corporation organized under the laws of the State of Iowa ("OPTION HOLDER").
 
                        W I T N E S S E T H    T H A T:
 
    WHEREAS,  concurrently with  the execution  and delivery  of this Agreement,
OPTION GRANTOR, OPTION HOLDER, Interstate Power Company, a corporation organized
under the laws of the State of Delaware ("INTERSTATE"), WPLH Acquisition Co.,  a
wholly-owned  subsidiary of OPTION GRANTOR organized under the laws of the State
of Wisconsin  ("ACQUISITION"),  and  Interstate Power  Company,  a  wholly-owned
subsidiary of Interstate organized under the laws of the State of Wisconsin, are
entering into an Agreement and Plan of Merger, dated as of November 10, 1995, as
amended (the "MERGER AGREEMENT"), which provides, INTER ALIA, upon the terms and
subject to the conditions thereof, for the merger of OPTION HOLDER with and into
OPTION  GRANTOR in accordance with the laws  of the States of Wisconsin and Iowa
(the "IES MERGER"), and the merger of Acquisition with and into Interstate (or a
successor thereto) in accordance with the laws of the States of Delaware  and/or
Wisconsin  (the  "INTERSTATE  MERGER", and  together  with the  IES  Merger, the
"MERGER");
 
    WHEREAS, in connection with  the execution of  the Merger Agreement,  OPTION
GRANTOR,  OPTION HOLDER  and Interstate are  entering into  certain stock option
agreements dated as of the date hereof, of which this Agreement is one,  whereby
the  parties hereto grant each other an option with respect to certain shares of
each other's common stock on the terms  and subject to the conditions set  forth
therein (the "STOCK OPTION AGREEMENTS"); and
 
    WHEREAS,  as a  condition to OPTION  HOLDER's willingness to  enter into the
Merger Agreement, OPTION  HOLDER has  requested that OPTION  GRANTOR agree,  and
OPTION  GRANTOR has so agreed, to grant  to OPTION HOLDER an option with respect
to certain shares of OPTION GRANTOR's common stock, on the terms and subject  to
the conditions set forth herein;
 
    NOW,  THEREFORE, to induce OPTION HOLDER  to enter into the Merger Agreement
and certain  of  the  Stock  Option Agreements,  and  in  consideration  of  the
representations,  warranties, covenants and agreements  contained herein, in the
Merger Agreement and in the Stock Option Agreements to which OPTION GRANTOR  and
OPTION  HOLDER are parties,  the parties hereto, intending  to be legally bound,
hereby agree as follows:
 
    1.  GRANT OF OPTION.
 
        (a) Subject  to  the receipt  of  all regulatory  approvals  and  orders
    required  by  OPTION GRANTOR  as  set forth  in  Section 4.4(c)  of  the WPL
    Disclosure Schedule to  the Merger  Agreement and  by OPTION  HOLDER as  set
    forth  in  Section  5.4(c) of  the  IES  Disclosure Schedule  to  the Merger
    Agreement, OPTION GRANTOR hereby grants OPTION HOLDER an irrevocable  option
    (the  "OPTION  GRANTOR OPTION")  to purchase  up to  that number  of shares,
    subject to  adjustment  as  provided  in Section  12  (the  "OPTION  GRANTOR
    SHARES"),  of common stock, par value $.01 per share, of OPTION GRANTOR (the
    "OPTION GRANTOR COMMON  STOCK") equal  to a percentage  (the "OPTION  SHARES
    PERCENTAGE"), which Option Shares Percentage is equal to the OPTION HOLDER's
    Participation  Percentage as defined  below in subsection  (e), of 6,123,944
    shares of OPTION GRANTOR Common Stock  (being 19.9% of the number of  shares
    of OPTION
 
                                      B-1
<PAGE>
    GRANTOR  Common Stock  issued and outstanding  as of November  10, 1995 (the
    "INITIAL NUMBER") in the manner set  forth below, at a price (the  "EXERCISE
    PRICE")  per OPTION  GRANTOR Share  of $30.675 (which  is equal  to the Fair
    Market Value (as defined below)  of an OPTION GRANTOR  Share as of the  date
    hereof).
 
        (b)  The Exercise Price shall be  payable, at OPTION HOLDER's option, as
    follows:
 
           (i) in cash, or
 
           (ii) subject  to the  receipt of  all approvals  of any  Governmental
       Authority  required for OPTION  GRANTOR to acquire,  and OPTION HOLDER to
       issue, the OPTION HOLDER Shares (as defined below) from OPTION HOLDER, in
       shares of common stock,  no par value, of  OPTION HOLDER ("OPTION  HOLDER
       SHARES"),
 
    in either case in accordance with Section 4 hereof.
 
        (c)  Notwithstanding  the foregoing,  in no  event  shall the  number of
    OPTION GRANTOR Shares  for which  the OPTION GRANTOR  Option is  exercisable
    exceed  the product of the Option  Shares Percentage and the Initial Number,
    subject to adjustment as provided in Section 12.
 
        (d) As used herein, the  "FAIR MARKET VALUE" of  any share shall be  the
    average  of the  daily closing sales  price for  such share on  the New York
    Stock Exchange (the "NYSE")  during the ten NYSE  trading days prior to  the
    fifth  NYSE trading day preceding  the date such Fair  Market Value is to be
    determined.
 
        (e) For purposes of this  Agreement the term "PARTICIPATION  PERCENTAGE"
    shall  have  the  same  meaning  as  in  Section  10.3(f)(i)  of  the Merger
    Agreement, except that  the numerator  and denominator  shall be  calculated
    based  on the number of  shares of WPL Common  Stock which would be issuable
    (or, in the case of  WPL, retained by its  shareholders) on a fully  diluted
    basis  had the Effective Time occurred as  of the date on which the Exercise
    Notice is delivered under Section 2 hereof  or the date on which demand  for
    the  Trigger Payment (as defined herein) is given under Section 5 hereof, as
    the case may be. Other capitalized terms used herein but not defined  herein
    shall have the meanings set forth in the Merger Agreement.
 
    2.  EXERCISE OF OPTION.
 
        (a)  The OPTION  GRANTOR Option  may be  exercised by  OPTION HOLDER, in
    whole or  in part,  at  any time  or  from time  to  time after  the  Merger
    Agreement  becomes  terminable by  OPTION  HOLDER under  circumstances which
    could entitle OPTION HOLDER  to a termination fee  under Section 10.3(a)  of
    the  Merger  Agreement  (provided  that  the  events  specified  in  Section
    10.3(a)(ii)(A) of the  Merger Agreement  shall have  occurred, although  the
    events  specified in Section 10.3(a)(ii)(B) thereof need not have occurred),
    or Section 10.3(b) of the Merger Agreement (regardless of whether the Merger
    Agreement is actually terminated  or whether there occurs  a closing of  any
    Business Combination involving a Target Party or a closing by which a Target
    Party  becomes a Subsidiary),  any such event by  which the Merger Agreement
    becomes so  terminable  by OPTION  HOLDER  being  referred to  herein  as  a
    "TRIGGER EVENT").
 
        (b)(i)  OPTION GRANTOR shall notify OPTION HOLDER promptly in writing of
       the occurrence of any Trigger Event, it being understood that the  giving
       of such notice by OPTION GRANTOR shall not be a condition to the right of
       OPTION HOLDER to exercise the OPTION GRANTOR Option.
 
           (ii) In the event OPTION HOLDER wishes to exercise the OPTION GRANTOR
       Option,  OPTION HOLDER shall deliver to OPTION GRANTOR written notice (an
       "EXERCISE NOTICE") specifying the total  number of OPTION GRANTOR  Shares
       it wishes to purchase.
 
          (iii)  Upon  the giving  by  OPTION HOLDER  to  OPTION GRANTOR  of the
       Exercise Notice  and  the tender  of  the applicable  aggregate  Exercise
       Price, OPTION HOLDER, to the
 
                                      B-2
<PAGE>
       extent  permitted by  law and OPTION  GRANTOR's organizational documents,
       and provided that the conditions to OPTION GRANTOR's obligation to  issue
       the OPTION GRANTOR Shares to OPTION HOLDER hereunder set forth in Section
       3  have been  satisfied or waived,  shall be  deemed to be  the holder of
       record  of  the  OPTION  GRANTOR  Shares  issuable  upon  such  exercise,
       notwithstanding  that the  stock transfer  books of  OPTION GRANTOR shall
       then be  closed or  that certificates  representing such  OPTION  GRANTOR
       Shares shall not then be actually delivered to OPTION HOLDER.
 
          (iv) Each closing of a purchase of OPTION GRANTOR Shares (a "CLOSING")
       shall  occur at a  place, on a date,  and at a  time designated by OPTION
       HOLDER in an Exercise Notice delivered  at least two business days  prior
       to the date of the Closing.
 
        (c) The OPTION GRANTOR Option shall terminate upon the earliest to occur
    of:
 
           (i) the Effective Time of the Merger;
 
           (ii) the termination of the Merger Agreement pursuant to Section 10.1
       thereof,  other than under circumstances  which also constitute a Trigger
       Event under this Agreement;
 
          (iii) 180 days following any termination of the Merger Agreement  upon
       or during the continuance of a Trigger Event (or if, at the expiration of
       such  180 day  period, the OPTION  GRANTOR Option cannot  be exercised by
       reason of any applicable judgment, decree, order, law or regulation,  ten
       business  days after such impediment to  exercise shall have been removed
       or shall have become  final and not  subject to appeal,  but in no  event
       under this clause (iii) later than May 10, 1998); and
 
          (iv)  payment by  OPTION GRANTOR of  the Trigger Payment  set forth in
       Section 5 of this Agreement to OPTION HOLDER.
 
        (d) Notwithstanding the foregoing, the OPTION GRANTOR Option may not  be
    exercised  if  (i)  OPTION  HOLDER  is in  material  breach  of  any  of its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in  this Agreement or in  the Merger Agreement,  or
    (ii) a Trigger Payment has been paid pursuant to Section 5 of this Agreement
    or demand therefor has been made and not withdrawn.
 
    3.   CONDITIONS TO CLOSING.   The obligation of  OPTION GRANTOR to issue the
OPTION GRANTOR Shares to  OPTION HOLDER hereunder is  subject to the  conditions
that
 
        (a)  all waiting periods,  if any, under  the HSR Act  applicable to the
    issuance and acquisition of the  OPTION GRANTOR Shares hereunder shall  have
    expired or have been terminated;
 
        (b)  the OPTION GRANTOR  Shares, and any OPTION  HOLDER Shares which are
    issued in  payment of  the  Exercise Price,  shall  have been  approved  for
    listing on the NYSE subject only to official notice of issuance;
 
        (c)   all  consents,   approvals,  orders   or  authorizations   of,  or
    registrations, declarations or  filings with,  any federal,  state or  local
    administrative  agency  or  commission  or  other  federal,  state  or local
    Governmental Authority, if any, required in connection with the issuance  by
    OPTION  GRANTOR and the  acquisition by OPTION HOLDER  of the OPTION GRANTOR
    Shares hereunder  shall  have  been obtained  or  made,  including,  without
    limitation,  the approval of the  SEC under Sections 9  and 10 of the Public
    Utility Holding  Company Act  of  1935, as  amended  (the "1935  ACT"),  the
    approval  of the Public  Service Commission of Wisconsin  of the issuance of
    the OPTION  GRANTOR  Shares  by  OPTION  GRANTOR  and,  if  applicable,  the
    acquisition  of OPTION GRANTOR Shares by  OPTION HOLDER, and the approval of
    the Iowa Utilities Board of the acquisition of the OPTION GRANTOR Shares  by
    OPTION  HOLDER and, if applicable, the  acquisition by OPTION GRANTOR of the
    OPTION HOLDER Shares constituting the Exercise Price hereunder; and
 
                                      B-3
<PAGE>
        (d) no preliminary or permanent injunction  or other order by any  court
    of competent jurisdiction prohibiting or otherwise restraining such issuance
    shall be in effect.
 
The  condition set forth in paragraph (b) above may be waived by OPTION GRANTOR,
in the case of OPTION HOLDER Shares, and by OPTION HOLDER, in the case of OPTION
GRANTOR Shares, in the sole discretion of the waiving party.
 
    4.  CLOSING.  At any Closing,
 
        (a) OPTION GRANTOR  shall deliver  to OPTION  HOLDER or  its designee  a
    single  certificate  in definitive  form representing  the number  of OPTION
    GRANTOR Shares  designated by  OPTION HOLDER  in its  Exercise Notice,  such
    certificate  to be registered in  the name of OPTION  HOLDER and to bear the
    legend set forth in Section 13; and
 
        (b) OPTION HOLDER shall  deliver to OPTION  GRANTOR the aggregate  price
    for the OPTION GRANTOR Shares so designated and being purchased by
 
           (i)  wire transfer of immediately  available funds or certified check
       or bank check, or
 
           (ii) subject  to the  condition in  Section 1(b)(ii),  delivery of  a
       certificate  or  certificates representing  the  number of  OPTION HOLDER
       Shares being issued by OPTION HOLDER in consideration thereof, determined
       in accordance with Section 4(c).
 
        (c) In  the event  that OPTION  HOLDER issues  OPTION HOLDER  Shares  to
    OPTION GRANTOR in consideration of OPTION GRANTOR Shares pursuant to Section
    4(b)(ii),  the number of OPTION HOLDER Shares to be so issued shall be equal
    to the quotient obtained by dividing:
 
           (i) the  product of  (x) the  number of  OPTION GRANTOR  Shares  with
       respect to which the OPTION GRANTOR Option is being exercised and (y) the
       Exercise Price, by
 
           (ii) the Fair Market Value of the OPTION HOLDER Shares as of the date
       immediately preceding the date the Exercise Notice is delivered to OPTION
       GRANTOR.
 
        (d)  OPTION GRANTOR  shall pay  all expenses,  and any  and all Federal,
    state and local taxes  and other charges that  may be payable in  connection
    with  the preparation, issue  and delivery of  stock certificates under this
    Section 4.
 
    5.  TRIGGER PAYMENT.
 
        (a) TRIGGER PAYMENT. Subject to the provisions of Section 10.3(e) of the
    Merger Agreement, if a Trigger Event shall have occurred and any  regulatory
    approval  or  order required  for  the issuance  by  OPTION GRANTOR,  or the
    acquisition by  OPTION HOLDER,  of  the OPTION  GRANTOR Option  pursuant  to
    Section  1 hereof shall not have been obtained, OPTION HOLDER shall have the
    right to receive, and OPTION GRANTOR  shall pay to OPTION HOLDER, an  amount
    (the "TRIGGER PAYMENT") equal to the product of
 
           (i)  the maximum number of OPTION GRANTOR Shares that would have been
       subject to purchase by OPTION HOLDER upon exercise of the OPTION  GRANTOR
       Option  pursuant  to  Sections 1  and  2  hereof if  all  such regulatory
       approvals or orders had been obtained, and
 
           (ii) the difference  between (A) the  Market/Offer Price (as  defined
       herein),  determined as  of the  date on which  notice of  demand for the
       Trigger Payment is  given by OPTION  HOLDER, and (B)  the Exercise  Price
       (but only if such Market/Offer Price is higher than such Exercise Price).
 
    Demand  for the Trigger Payment shall be  given by notice in accordance with
    the provisions of Section  17 hereof. The Trigger  Payment shall be paid  to
    OPTION HOLDER by OPTION
 
                                      B-4
<PAGE>
    GRANTOR  on  the  Payment Date  (as  defined  herein), by  wire  transfer of
    immediately available funds  to an account  to be designated  in writing  by
    OPTION HOLDER not less than two business days before the Payment Date.
 
        (b)  PAYMENT DATE.  For purposes of this Section 5, "PAYMENT DATE" means
    the date on which termination fees are required to be paid by OPTION GRANTOR
    to  OPTION HOLDER under Section  10.3(a) or 10.3(b), as  the case may be, of
    the Merger Agreement  as a  result of the  occurrence of  the Trigger  Event
    referred to in subsection (a) of this Section 5.
 
        (c)  CERTAIN CONDITIONS.  OPTION GRANTOR shall have no obligation to pay
    the  Trigger Payment if  OPTION HOLDER is  in material breach  of any of its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in this Agreement or in the Merger Agreement.
 
    6.   REPRESENTATIONS  AND WARRANTIES  OF  OPTION GRANTOR.    OPTION  GRANTOR
represents and warrants to OPTION HOLDER that
 
        (a) except as set forth in Section 4.4(a) of the WPL Disclosure Schedule
    to  the  Merger  Agreement,  OPTION  GRANTOR  has  the  corporate  power and
    authority to enter  into this  Agreement and  to carry  out its  obligations
    hereunder,  subject  in the  case of  the repurchase  of the  OPTION GRANTOR
    Shares pursuant to  Section 8(a)  to applicable  law and  the provisions  of
    OPTION  GRANTOR's Articles of Incorporation, as amended (the "OPTION GRANTOR
    ARTICLES");
 
        (b) this Agreement has been duly  and validly executed and delivered  by
    OPTION  GRANTOR, and, assuming the due authorization, execution and delivery
    hereof  by  OPTION  HOLDER  and  the  receipt  of  all  required  regulatory
    approvals,  constitutes a  valid and  binding obligation  of OPTION GRANTOR,
    enforceable against OPTION GRANTOR in  accordance with its terms, except  as
    may be limited by applicable bankruptcy, insolvency, reorganization or other
    similar  laws affecting the enforcement  of creditors' rights generally, and
    except that  the  availability  of equitable  remedies,  including  specific
    performance,  may be subject to the discretion of any court before which any
    proceeding therefor may be brought;
 
        (c) OPTION GRANTOR has taken all necessary corporate action to authorize
    and reserve for issuance  and to permit  it to issue,  upon exercise of  the
    OPTION  GRANTOR Option, and  at all times  from the date  hereof through the
    expiration of  the OPTION  GRANTOR Option  will have  reserved, the  Initial
    Number  of authorized and unissued OPTION  GRANTOR Shares, such amount being
    subject to adjustment as  provided in Section 12,  all of which, upon  their
    issuance  and delivery in accordance with  the terms of this Agreement, will
    be duly authorized, validly issued, fully paid and nonassessable (except  as
    otherwise provided in Section 180.0622(2)(b) of the WBCL);
 
        (d) upon delivery of the OPTION GRANTOR Shares to OPTION HOLDER upon the
    exercise of the OPTION GRANTOR Option, OPTION HOLDER will acquire the OPTION
    GRANTOR  Shares free and  clear of all  claims, liens, charges, encumbrances
    and security interests of any nature whatsoever;
 
        (e) except as described in Section 4.4(b) of the WPL Disclosure Schedule
    to the Merger  Agreement, the execution  and delivery of  this Agreement  by
    OPTION  GRANTOR does not, and, subject to compliance with applicable law and
    the OPTION GRANTOR  Articles with respect  to the repurchase  of the  OPTION
    GRANTOR  Shares pursuant to Section 8(a), the consummation by OPTION GRANTOR
    of the transactions contemplated hereby will not violate, conflict with,  or
    result  in a breach  of any provision  of, or constitute  a default (with or
    without notice  or  a lapse  of  time, or  both)  under, or  result  in  the
    termination  of, or accelerate  the performance required by,  or result in a
    right of termination, cancellation, or acceleration of any obligation or the
    loss of  a  material benefit  under,  or the  creation  of a  lien,  pledge,
    security interest or other encumbrance on
 
                                      B-5
<PAGE>
    assets  (any  such  conflict,  violation,  default,  right  of  termination,
    cancellation, acceleration, loss or creation, hereinafter a "VIOLATION")  of
    OPTION GRANTOR or any of its Subsidiaries, pursuant to
 
           (i)  any provision  of the OPTION  GRANTOR Articles or  the Bylaws of
       OPTION GRANTOR,
 
           (ii) any provisions of any  material loan or credit agreement,  note,
       mortgage,  indenture, lease, benefit plan or other agreement, obligation,
       instrument,  permit,  concession,  franchise  or  license  (any  of   the
       foregoing  in effect on the date hereof  being referred to as a "MATERIAL
       CONTRACT") of OPTION GRANTOR or its subsidiaries or to which any of  them
       is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable to OPTION GRANTOR or its properties or assets,
 
    which Violation,  in  the  case  of  each  clauses  (ii)  and  (iii),  could
    reasonably  be expected  to have an  OPTION GRANTOR  Material Adverse Effect
    (except that no representation or warranty is given concerning any Violation
    of a Material  Contract with  respect to  the repurchase  of OPTION  GRANTOR
    Shares pursuant to Section 8(a));
 
        (f) except as described in Section 4.4(c) of the WPL Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of  this Agreement by OPTION  GRANTOR does not, and  the performance of this
    Agreement by  OPTION  GRANTOR  will  not,  require  any  consent,  approval,
    authorization or permit of, filing with or notification to, any Governmental
    Authority;
 
        (g)  none of OPTION GRANTOR,  any of its affiliates  or anyone acting on
    its or their  behalf, has  issued, sold or  offered any  security of  OPTION
    GRANTOR  to any person under circumstances that would cause the issuance and
    sale of OPTION  GRANTOR Shares,  as contemplated  by this  Agreement, to  be
    subject  to the registration requirements of the Securities Act as in effect
    on the  date hereof,  and, assuming  the representations  and warranties  of
    OPTION  HOLDER contained in Section 7(g) are true and correct, the issuance,
    sale and delivery  of the OPTION  GRANTOR Shares hereunder  would be  exempt
    from the registration and prospectus delivery requirements of the Securities
    Act,  as in effect on the date hereof (and OPTION GRANTOR shall not take any
    action which would cause the issuance, sale, and delivery of OPTION  GRANTOR
    Shares hereunder not to be exempt from such requirements); and
 
        (h) any OPTION HOLDER Shares acquired pursuant to this Agreement will be
    acquired for OPTION GRANTOR's own account, for investment purposes only, and
    will  not  be  acquired  by  OPTION  GRANTOR  with  a  view  to  the  public
    distribution thereof  in  violation  of  any  applicable  provision  of  the
    Securities Act.
 
    7.    REPRESENTATIONS  AND  WARRANTIES  OF  OPTION  HOLDER.    OPTION HOLDER
represents and warrants to OPTION GRANTOR that
 
        (a) except  as  set forth  in  Schedule  5.4(a) of  the  IES  Disclosure
    Schedule  to the Merger Agreement, OPTION HOLDER has the corporate power and
    authority to enter  into this  Agreement and  to carry  out its  obligations
    hereunder;
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION HOLDER and,  assuming the due  authorization, execution and  delivery
    hereof  by  OPTION  GRANTOR  and  the  receipt  of  all  required regulatory
    approvals, constitutes  a valid  and binding  obligation of  OPTION  HOLDER,
    enforceable  against OPTION HOLDER in  accordance with its respective terms,
    except  as   may   be   limited  by   applicable   bankruptcy,   insolvency,
    reorganization,   or  other  similar  laws   affecting  the  enforcement  of
    creditors' rights generally, and except  that the availability of  equitable
    remedies,  including specific performance, may  be subject to the discretion
    of any court before which any proceeding may be brought;
 
                                      B-6
<PAGE>
        (c) prior to any  delivery of OPTION HOLDER  Shares in consideration  of
    the  purchase of OPTION  GRANTOR Shares pursuant  hereto, OPTION HOLDER will
    have taken all necessary corporate action  to authorize for issuance and  to
    permit  it to  issue such  OPTION HOLDER  Shares, all  of which,  upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d)  upon any delivery of such OPTION HOLDER Shares to OPTION GRANTOR in
    consideration of  the purchase  of OPTION  GRANTOR Shares  pursuant  hereto,
    OPTION  GRANTOR will acquire the OPTION HOLDER  Shares free and clear of all
    claims, liens, charges,  encumbrances and security  interests of any  nature
    whatsoever;
 
        (e) except as described in Section 5.4(b) of the IES Disclosure Schedule
    to  the Merger  Agreement, the execution  and delivery of  this Agreement by
    OPTION HOLDER  does  not, and  the  consummation  by OPTION  HOLDER  of  the
    transactions contemplated hereby will not, violate, conflict with, or result
    in  the breach of any provision of, or constitute a default (with or without
    notice or a lapse  of time, or  both) under, or result  in any Violation  by
    OPTION HOLDER or any of its Subsidiaries, pursuant to
 
           (i)  any  provision of  the Articles  of  Incorporation or  Bylaws of
       OPTION HOLDER,
 
           (ii)  any  Material  Contract  of   OPTION  HOLDER  or  any  of   its
       subsidiaries or to which any of them is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable to OPTION HOLDER or its properties or assets,
 
    which Violation, in the case of each of clauses (ii) or (iii), would have an
    OPTION HOLDER Material Adverse Effect;
 
        (f) except as described in Section 5.4(c) of the IES Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of this Agreement by OPTION HOLDER does not, and the consummation by  OPTION
    HOLDER  of  the  transactions  contemplated  hereby  will  not,  require any
    consent, approval, authorization or permit  of, filing with or  notification
    to, any Governmental Authority; and
 
        (g)  any  OPTION GRANTOR  Shares acquired  upon  exercise of  the OPTION
    GRANTOR Option  will  be  acquired  for OPTION  HOLDER's  own  account,  for
    investment  purposes only and will not be,  and the OPTION GRANTOR Option is
    not being, acquired by OPTION HOLDER with a view to the public  distribution
    thereof, in violation of any applicable provision of the Securities Act.
 
    8.  CERTAIN REPURCHASES.
 
        (a)   OPTION HOLDER "PUT".   At the request  of OPTION HOLDER by written
    notice (x) at any time during which the OPTION GRANTOR Option is exercisable
    pursuant to  Section 2  (the "REPURCHASE  PERIOD"), OPTION  GRANTOR (or  any
    successor  entity thereof) shall, if permitted by applicable law, the OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase  from  OPTION HOLDER  all or  any portion  of the  OPTION GRANTOR
    Option, at the price  set forth in  subparagraph (i) below,  or, (y) at  any
    time prior to May 10, 1997 (provided that such date shall be extended to May
    10, 1998 under the circumstances where the date after which either party may
    terminate  the Merger  Agreement pursuant to  Section 10.1(b)  of the Merger
    Agreement has  been  extended to  May  10,  1998), OPTION  GRANTOR  (or  any
    successor  entity thereof) shall, if permitted by applicable law, the OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase  from  OPTION HOLDER  all or  any portion  of the  OPTION GRANTOR
    Shares purchased by OPTION HOLDER pursuant to the OPTION GRANTOR Option,  at
    the price set forth in subparagraph (ii) below:
 
                                      B-7
<PAGE>
         (i)(A)  The  difference between  the  "Market/Offer Price"  (as defined
       below) for shares of  OPTION GRANTOR Common Stock  as of the date  OPTION
       HOLDER  gives  notice of  its intent  to exercise  its rights  under this
       Section 8 and  the Exercise  Price, multiplied  by the  number of  OPTION
       GRANTOR  Shares  purchasable pursuant  to the  OPTION GRANTOR  Option (or
       portion thereof with  respect to  which OPTION HOLDER  is exercising  its
       rights  under  this Section  8), but  only if  the Market/Offer  Price is
       greater than the Exercise Price.
 
           (B) For purposes of this Agreement, "MARKET/OFFER PRICE" shall  mean,
       as  of any date, the higher of (I) the price per share offered as of such
       date pursuant to any tender or exchange offer or other offer with respect
       to a Business Combination  involving OPTION GRANTOR  as the Target  Party
       which  was made prior to such date  and not terminated or withdrawn as of
       such date and (II) the Fair  Market Value of OPTION GRANTOR Common  Stock
       as of such date.
 
        (ii)(A)  The product of  (I) the sum  of (a) the  Exercise Price paid by
       OPTION HOLDER per OPTION  GRANTOR Share acquired  pursuant to the  OPTION
       GRANTOR  Option, and  (b) the  difference between  the "Offer  Price" (as
       defined below) and  the Exercise Price,  but only if  the Offer Price  is
       greater  than the Exercise  Price, and (II) the  number of OPTION GRANTOR
       Shares so to be repurchased pursuant to this Section 8.
 
           (B) For purposes of this clause (ii), the "OFFER PRICE" shall be  the
       highest price per share offered pursuant to a tender or exchange offer or
       other  Business Combination offer involving  OPTION GRANTOR as the Target
       Party during the Repurchase Period prior to the delivery by OPTION HOLDER
       of a notice of repurchase.
 
        (b)  REDELIVERY OF  OPTION HOLDER SHARES.   If OPTION HOLDER shall  have
    previously  elected  to  purchase  OPTION  GRANTOR  Shares  pursuant  to the
    exercise of the OPTION GRANTOR Option by the issuance and delivery of OPTION
    HOLDER Shares, then OPTION GRANTOR shall, if so requested by OPTION  HOLDER,
    in  fulfillment of its obligation pursuant to Section 8(a)(y) (that is, with
    respect to the Exercise Price only and without limitation to its  obligation
    to pay additional consideration under clause (b) of Section 8(a)(ii)(A)(I)),
    redeliver  the certificates for such OPTION  HOLDER Shares to OPTION HOLDER,
    free and clear of all liens, claims, charges and encumbrances of any kind or
    nature whatsoever; PROVIDED, HOWEVER, that if  at any time less than all  of
    the  OPTION GRANTOR  Shares so  purchased by  OPTION HOLDER  pursuant to the
    OPTION GRANTOR Option are  to be repurchased by  OPTION GRANTOR pursuant  to
    Section  8(a)(y), then (i) OPTION GRANTOR shall be obligated to redeliver to
    OPTION HOLDER the same proportion of such OPTION HOLDER Shares as the number
    of OPTION GRANTOR Shares that OPTION GRANTOR is then obligated to repurchase
    bears to the number of OPTION GRANTOR Shares acquired by OPTION HOLDER  upon
    exercise  of the OPTION GRANTOR Option and (ii) OPTION HOLDER shall issue to
    OPTION GRANTOR  new certificates  representing  those OPTION  HOLDER  Shares
    which  are  not due  to be  redelivered  to OPTION  HOLDER pursuant  to this
    Section 8(b) to the extent that excess OPTION HOLDER Shares are included  in
    the certificates redelivered to OPTION HOLDER by OPTION GRANTOR.
 
        (c)   PAYMENT AND REDELIVERY OF OPTION GRANTOR OPTIONS OR SHARES. In the
    event OPTION  HOLDER  exercises its  rights  under this  Section  8,  OPTION
    GRANTOR  shall, within ten business days thereafter, pay the required amount
    to OPTION  HOLDER in  immediately available  funds and  OPTION HOLDER  shall
    surrender  to OPTION GRANTOR the OPTION GRANTOR Option or the certificate or
    certificates evidencing the OPTION GRANTOR Shares purchased by OPTION HOLDER
    pursuant hereto, and  OPTION HOLDER shall  warrant that it  owns the  OPTION
    GRANTOR  Option or such  shares and that  the OPTION GRANTOR  Option or such
    shares are then free  and clear of all  liens, claims, damages, charges  and
    encumbrances of any kind or nature whatsoever.
 
                                      B-8
<PAGE>
        (d)   OPTION HOLDER  "CALL".  If  OPTION HOLDER has  elected to purchase
    OPTION GRANTOR Shares pursuant to the exercise of the OPTION GRANTOR  Option
    by  the issuance and delivery of  OPTION HOLDER Shares, notwithstanding that
    OPTION HOLDER may  no longer  hold any such  OPTION GRANTOR  Shares or  that
    OPTION  HOLDER elects not to exercise its other rights under this Section 8,
    OPTION HOLDER may require, at any time or from time to time prior to May 10,
    1997 (provided that such date  shall be extended to  May 10, 1998 under  the
    circumstances  where the  date after  which either  party may  terminate the
    Merger Agreement pursuant  to Section  10.1(b) of the  Merger Agreement  has
    been  extended to May 10, 1998), OPTION GRANTOR to sell to OPTION HOLDER any
    such OPTION HOLDER  Shares at  the price  attributed to  such OPTION  HOLDER
    Shares pursuant to Section 4 plus interest at the rate of 8.75% per annum on
    such  amount from the Closing  Date relating to the  exchange of such OPTION
    HOLDER Shares pursuant to Section 4  to the Closing Date under this  Section
    8(d) less any dividends on such OPTION HOLDER Shares paid during such period
    or  declared and  payable to  stockholders of record  on a  date during such
    period.
 
        (e)  REPURCHASE PRICE REDUCED AT  OPTION HOLDER'S OPTION.  In the  event
    the repurchase price specified in Section 8(a) would subject the purchase of
    the  OPTION GRANTOR Option or the  OPTION GRANTOR Shares purchased by OPTION
    HOLDER pursuant to the OPTION GRANTOR  Option to a vote of the  shareholders
    of OPTION GRANTOR pursuant to applicable law or the OPTION GRANTOR Articles,
    then  OPTION HOLDER may, at its election,  reduce the repurchase price to an
    amount which would permit such repurchase  without the necessity for such  a
    shareholder vote.
 
    9.   VOTING  OF SHARES.   Following the date  hereof and prior  to the fifth
anniversary of the date  hereof (the "EXPIRATION DATE"),  each party shall  vote
any  shares of capital stock of the  other party acquired by such party pursuant
to this  Agreement ("RESTRICTED  SHARES"), including  any OPTION  HOLDER  Shares
issued  pursuant to  Section 1(b), or  otherwise beneficially  owned (within the
meaning of Rule 13d-3 promulgated under the Securities Exchange Act of 1934,  as
amended  (the "EXCHANGE ACT")), by such party on each matter submitted to a vote
of shareholders of  such other party  for and  against such matter  in the  same
proportion  as the vote of all other  shareholders of such other party are voted
(whether by proxy or otherwise) for and against such matter.
 
    10.  RESTRICTIONS ON TRANSFER.
 
        (a)  RESTRICTIONS ON  TRANSFER.  Prior to  the Expiration Date,  neither
    party shall, directly or indirectly, by operation of law or otherwise, sell,
    assign,  pledge, or otherwise  dispose of or  transfer any Restricted Shares
    beneficially owned by such party, other  than (i) pursuant to Section 8,  or
    (ii) in accordance with Section 10(b) or Section 11.
 
        (b)    PERMITTED  SALES.    Following  the  termination  of  the  Merger
    Agreement, a  party  shall  be  permitted  to  sell  any  Restricted  Shares
    beneficially  owned  by it  if such  sale is  made pursuant  to a  tender or
    exchange  offer  that  has  been  approved  or  recommended,  or   otherwise
    determined  to be fair to  and in the best  interests of the shareholders of
    the other party, by a majority of  the members of the Board of Directors  of
    such  other party, which majority shall  include a majority of directors who
    were directors prior to the announcement of such tender or exchange offer.
 
    11.  REGISTRATION RIGHTS.
 
        (a) Following  the termination  of the  Merger Agreement,  either  party
    hereto  that owns Restricted  Shares (a "DESIGNATED  HOLDER") may by written
    notice (the "REGISTRATION  NOTICE") to  the other  party (the  "REGISTRANT")
    request  the Registrant to register under the Securities Act all or any part
    of the Restricted Shares beneficially  owned by such Designated Holder  (the
    "REGISTRABLE   SECURITIES")  pursuant   to  a  bona   fide  firm  commitment
    underwritten public  offering,  in  which  the  Designated  Holder  and  the
    underwriters  shall  effect  as  wide  a  distribution  of  such Registrable
    Securities as is reasonably practicable and shall use their best efforts  to
    prevent any person
 
                                      B-9
<PAGE>
    (including any Group (as used in Rule 13d-5 under the Exchange Act)) and its
    affiliates   from  purchasing   through  such   offering  Restricted  Shares
    representing more than 1% of the  outstanding shares of common stock of  the
    Registrant on a fully diluted basis (a "PERMITTED OFFERING").
 
        (b)  The Registration Notice shall include a certificate executed by the
    Designated Holder and its  proposed managing underwriter, which  underwriter
    shall  be an investment banking firm  of nationally recognized standing (the
    "MANAGER"), stating that
 
           (i) they have a good faith intention to commence promptly a Permitted
       Offering, and
 
           (ii)  the  manager  in  good  faith  believes  that,  based  on   the
       then-prevailing   market  conditions,  it  will   be  able  to  sell  the
       Registrable Securities at a per share price equal to at least 80% of  the
       then Fair Market Value of such shares.
 
        (c)  The  Registrant (and/or  any person  designated by  the Registrant)
    shall thereupon have the option  exercisable by written notice delivered  to
    the  Designated Holder  within ten  business days  after the  receipt of the
    Registration Notice, irrevocably to agree to purchase all or any part of the
    Registrable Securities  proposed to  be so  sold for  cash at  a price  (the
    "OPTION  PRICE")  equal to  the  product of  (i)  the number  of Registrable
    Securities to  be so  purchased by  the Registrant  and (ii)  the then  Fair
    Market Value of such shares.
 
        (d)  Any purchase  of Registrable Securities  by the  Registrant (or its
    designee) under Section 11(c) shall  take place at a  closing to be held  at
    the  principal executive offices of the Registrant  or at the offices of its
    counsel at any reasonable date and time designated by the Registrant  and/or
    such  designee in such notice within  twenty business days after delivery of
    such notice, and any payment for the shares to be so purchased shall be made
    by delivery at the time of such closing in immediately available funds.
 
        (e) If the Registrant does not elect to exercise its option pursuant  to
    this Section 11 with respect to all Registrable Securities, it shall use its
    best  efforts to effect, as promptly  as practicable, the registration under
    the Securities Act of the unpurchased Registrable Securities proposed to  be
    so sold; PROVIDED, HOWEVER, that
 
           (i)  neither party shall be entitled to demand more than an aggregate
       of two effective registration statements hereunder, and
 
           (ii)  the  Registrant  will  not   be  required  to  file  any   such
       registration  statement during any period of  time (not to exceed 40 days
       after such request in the case of clause (A) below or 90 days in the case
       of clauses (B) and (C) below) when
 
               (A) the  Registrant  is  in  possession  of  material  non-public
           information  which it reasonably believes  would be detrimental to be
           disclosed at  such  time  and,  in the  opinion  of  counsel  to  the
           Registrant,  such information would be required  to be disclosed if a
           registration statement were filed at that time;
 
               (B) the  Registrant  is  required under  the  Securities  Act  to
           include   audited  financial  statements  for   any  period  in  such
           registration statement  and such  financial  statements are  not  yet
           available for inclusion in such registration statement; or
 
               (C)  the Registrant determines, in  its reasonable judgment, that
           such registration would interfere with any financing, acquisition  or
           other  material transaction  involving the  Registrant or  any of its
           affiliates.
 
        (f) The Registrant shall  use its reasonable best  efforts to cause  any
    Registrable  Securities  registered  pursuant  to  this  Section  11  to  be
    qualified  for  sale  under  the  securities  or  Blue  Sky  laws  of   such
    jurisdictions  as  the Designated  Holder may  reasonably request  and shall
    continue such registration or qualification in effect in such  jurisdiction;
    PROVIDED,  HOWEVER, that the Registrant shall  not be required to qualify to
    do  business  in,  or  consent  to  general  service  of  process  in,   any
    jurisdiction by reason of this provision.
 
                                      B-10
<PAGE>
        (g)  The registration rights set forth in this Section 11 are subject to
    the condition that the Designated  Holder shall provide the Registrant  with
    such  information with respect to  such holder's Registrable Securities, the
    plans for the distribution thereof, and such other information with  respect
    to such holder as, in the reasonable judgment of counsel for the Registrant,
    is  necessary  to  enable the  Registrant  to include  in  such registration
    statement all material  facts required  to be  disclosed with  respect to  a
    registration thereunder.
 
        (h)  A registration effected under this  Section 11 shall be effected at
    the Registrant's expense, except for underwriting discounts and  commissions
    and  the fees and the expenses of  counsel to the Designated Holder, and the
    Registrant shall provide to  the underwriters such documentation  (including
    certificates, opinions of counsel and "comfort" letters from auditors) as is
    customary   in  connection  with  underwritten   public  offerings  as  such
    underwriters may reasonably require.
 
        (i) In connection with any registration effected under this Section  11,
    the parties agree
 
           (i)  to indemnify  each other and  the underwriters  in the customary
       manner,
 
           (ii) to enter into  an underwriting agreement  in form and  substance
       customary  for transactions of  such type with the  Manager and the other
       underwriters participating in such offering, and
 
          (iii) to take all further actions which shall be reasonably  necessary
       to  effect such registration and sale  (including if the Manager deems it
       necessary, participating in road-show presentations).
 
        (j)   The Registrant  shall  be entitled  to  include (at  its  expense)
    additional shares of its common stock in a registration effected pursuant to
    this  Section 11 only if and to  the extent the Manager determines that such
    inclusion will  not  adversely affect  the  prospects for  success  of  such
    offering.
 
    12.   ADJUSTMENT UPON CHANGES IN  CAPITALIZATION.  Without limitation to any
restriction on  OPTION GRANTOR  contained in  this Agreement  or in  the  Merger
Agreement,  in the event of any change  in OPTION GRANTOR Common Stock by reason
of   stock   dividends,   splitups,    mergers   (other   than   the    Merger),
recapitalizations,  combinations, exchange of  shares or the  like, the type and
number of shares  or securities subject  to the OPTION  GRANTOR Option, and  the
purchase  price per share provided in Section 1, shall be adjusted appropriately
to restore  to  OPTION HOLDER  its  rights  hereunder, including  the  right  to
purchase from OPTION GRANTOR (or its successors) shares of OPTION GRANTOR Common
Stock (or such other shares or securities into which OPTION GRANTOR Common Stock
has  been so changed)  representing the Option Shares  Percentage of the Initial
Number of shares of OPTION GRANTOR Common Stock for the aggregate Exercise Price
calculated as of the date of this Agreement as provided in Section 1.
 
    13.   RESTRICTIVE LEGENDS.   Each  certificate representing  OPTION  GRANTOR
Shares  issued to  OPTION HOLDER  hereunder, and  OPTION HOLDER  Shares, if any,
delivered  to  OPTION  GRANTOR  at  a   Closing,  shall  include  a  legend   in
substantially the following form:
 
    THE  SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
    UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES OR
    BLUE SKY LAWS, AND MAY BE REOFFERED OR SOLD ONLY IF SO REGISTERED OR  IF
    AN  EXEMPTION FROM SUCH  REGISTRATION IS AVAILABLE.  SUCH SECURITIES ARE
    ALSO SUBJECT TO ADDITIONAL RESTRICTIONS ON
 
                                      B-11
<PAGE>
    TRANSFER AS SET  FORTH IN  THE OPTION  HOLDER STOCK  OPTION AND  TRIGGER
    PAYMENT AGREEMENT, DATED AS OF NOVEMBER 10, 1995, A COPY OF WHICH MAY BE
    OBTAINED FROM THE ISSUER UPON REQUEST.
 
It is understood and agreed that:
 
        (i)  the reference to the resale  restrictions of the Securities Act and
    state securities or Blue Sky  laws in the above  legend shall be removed  by
    delivery  of  substitute  certificate(s) without  such  reference  if OPTION
    HOLDER or OPTION GRANTOR, as  the case may be,  shall have delivered to  the
    other  party a copy of a letter from the  staff of the SEC, or an opinion of
    counsel, in  form and  substance satisfactory  to the  other party,  to  the
    effect  that such legend is not required  for purposes of the Securities Act
    or such laws;
 
        (ii) the reference  to the  provisions to  this Agreement  in the  above
    legend  shall be  removed by  delivery of  substitute certificate(s) without
    such reference if  the shares have  been sold or  transferred in  compliance
    with  the provisions of  this Agreement and under  circumstances that do not
    require the retention of such reference; and
 
       (iii) the legend shall  be removed in its  entirety if the conditions  in
    the preceding clauses (i) and (ii) are both satisfied.
 
In addition, such certificates shall bear any other legend as may be required by
law.  Certificates  representing shares  sold  in a  registered  public offering
pursuant to Section 11  shall not be  required to bear the  legend set forth  in
this Section 13.
 
    14.  BINDING EFFECT; NO ASSIGNMENT; NO THIRD PARTY BENEFICIARIES.
 
        (a) This Agreement shall be binding upon and inure to the benefit of the
    parties hereto and their respective successors and permitted assigns.
 
        (b)  Except as  expressly provided for  in this  Agreement, neither this
    Agreement  nor  the  rights  or  obligations  of  either  party  hereto  are
    assignable,  except by operation of law, or  with the written consent of the
    other party.
 
        (c) Nothing contained in this Agreement, express or implied, is intended
    to confer upon any person other than the parties hereto and their respective
    successors and  permitted  assigns any  rights  or remedies  of  any  nature
    whatsoever by reason of this Agreement.
 
        (d)  Any  Restricted  Shares sold  by  a  party in  compliance  with the
    provisions of Section 11 shall, upon  consummation of such sale, be free  of
    the  restrictions imposed  with respect  to such  shares by  this Agreement,
    unless and  until  such  party  shall repurchase  or  otherwise  become  the
    beneficial owner of such shares, and any transferee of such shares shall not
    be entitled to the registration rights of such party.
 
    15.   SPECIFIC PERFORMANCE.  The  parties hereto agree that irreparable harm
would occur in the event that any  of the provisions of this Agreement were  not
performed  in accordance with their specified  terms or were otherwise breached.
It is  accordingly  agreed that  the  parties hereto  shall  be entitled  to  an
injunction  or injunctions to prevent breaches  of this Agreement and to enforce
specifically the terms and provisions hereof  in any court of the United  States
or  any state having jurisdiction, this being in addition to any other remedy to
which they are entitled at law or equity.
 
    16.  VALIDITY.
 
        (a)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement  shall  not affect  the validity  or  enforceability of  the other
    provisions of this Agreement, which shall remain in full force and effect.
 
        (b) In  the event  any  court or  other  competent authority  holds  any
    provisions  of this Agreement to be null, void or unenforceable, the parties
    hereto shall negotiate in good faith the
 
                                      B-12
<PAGE>
    execution and delivery of an amendment to this Agreement in order, as nearly
    as possible, to effectuate,  to the extent permitted  by law, the intent  of
    the  parties hereto with respect to  such provision and the economic effects
    thereof.
 
        (c) Subject to Section 5, if for any reason any such court or regulatory
    agency determines that OPTION HOLDER is not permitted to acquire, or  OPTION
    GRANTOR  is  not permitted  to repurchase  pursuant to  Section 8,  the full
    number of shares of OPTION GRANTOR Common Stock provided in Section 1 hereof
    (as the same may be adjusted), it is the express intention of OPTION GRANTOR
    to allow OPTION HOLDER to acquire or to require OPTION GRANTOR to repurchase
    such lesser number of shares as may be permissible without any amendment  or
    modification hereof.
 
        (d)  Each  party  agrees  that,  should  any  court  or  other competent
    authority hold any provision  of this Agreement or  part hereof to be  null,
    void  or unenforceable, or  order any party to  take any action inconsistent
    herewith, or not take any action required herein, the other party shall  not
    be  entitled to specific performance of such  provision or part hereof or to
    any other remedy,  including but not  limited to money  damages, for  breach
    hereof  or of any  other provision of  this Agreement or  part hereof as the
    result of such holding or order.
 
    17.  NOTICES.   All notices and other  communications hereunder shall be  in
writing and shall be deemed given if (a) delivered personally, or (b) if sent by
overnight courier service (receipt confirmed in writing), or (c) if delivered by
facsimile  transmission (with receipt  confirmed), or (d)  five days after being
mailed by registered or certified mail (return receipt requested) to the parties
in each case to the following addresses (or at such other address for a party as
shall be specified by like notice):
 
    A.    If to OPTION HOLDER, to:
          IES Industries Inc.
          IES Tower
          200 First Street S.E.
          Cedar Rapids, Iowa 52401
          Attention: Lee Liu
          Fax: (319) 398-4204
          with a copy to:
          Winthrop, Stimson, Putnam & Roberts
          One Battery Park Plaza
          New York, New York 10004-1490
          Attention: Stephen R. Rusmisel, Esq.
          Fax: (212) 858-1500
    B.    If to OPTION GRANTOR, to:
          WPL Holdings, Inc.
          222 West Washington Avenue
          Madison, Wisconsin 53703
          Attention: Erroll B. Davis, Jr.
          Fax: (608) 252-5059
          with a copy to:
          Foley & Lardner
          777 East Wisconsin Avenue
          Milwaukee, Wisconsin 53202-5367
          Attention: Benjamin F. Garmer, III, Esq.
          Fax: (414) 297-4900
 
                                      B-13
<PAGE>
    18.  GOVERNING LAW.   This Agreement shall be  governed by and construed  in
accordance  with the laws of the State of Delaware applicable to agreements made
and to be performed entirely within such State and without regard to its  choice
of law principles or to any requirement as to jurisdiction or service of process
contained in Section 2708 of Title 6 of the Delaware Code.
 
    19.  INTERPRETATION.
 
        (a)  When reference is  made in this Agreement  to Articles, Sections or
    Exhibits, such reference shall be to an Article, Section or Exhibit of  this
    Agreement, as the case may be, unless otherwise indicated.
 
        (b)  The table of contents and  headings contained in this Agreement are
    for reference  purposes and  shall not  affect  in any  way the  meaning  or
    interpretation of the Agreement.
 
        (c) Whenever the words "include," "includes," or "including" are used in
    this  Agreement, they shall be  deemed to be followed  by the words "without
    limitation."
 
        (d) Whenever "or" is used in this Agreement it shall be construed in the
    nonexclusive sense.
 
    20.  COUNTERPARTS; EFFECT.   This Agreement may be  executed in one or  more
counterparts,  each of which shall be deemed to be an original, but all of which
shall constitute one and the same agreement.
 
    21.   AMENDMENTS; WAIVER.   This  Agreement may  be amended  by the  parties
hereto  and the terms and conditions hereof  may be waived only by an instrument
in writing signed on behalf of each of the parties hereto, or, in the case of  a
waiver, by an instrument signed on behalf of the party waiving compliance.
 
    22.   EXTENSION OF TIME PERIODS.   The time periods for exercises of certain
rights under Sections 2, 7 and 8 shall be extended (but in no event by more than
six months):
 
        (a) to the extent necessary to  obtain all regulatory approvals for  the
    exercise  of such  rights, and for  the expiration of  all statutory waiting
    periods; and
 
        (b) to the extent necessary to  avoid any liability under Section  16(b)
    of the Exchange Act by reason of such exercise.
 
    IN  WITNESS WHEREOF,  the parties  hereto have  caused this  Agreement to be
executed by their respective duly authorized officers as of the date first above
written.
 
                                          WPL HOLDINGS, INC.
 
                                          By: /s/ ERROLL B. DAVIS, JR.
 
                                          --------------------------------------
                                          Name: Erroll B. Davis, Jr.
                                          Title: President and Chief
                                               Executive Officer
 
                                          IES INDUSTRIES INC.
                                          By: /s/ LEE LIU
 
                                          --------------------------------------
                                          Name: Lee Liu
                                          Title: Chairman of the Board,
                                                 President and Chief
                                               Executive Officer
 
                                      B-14
<PAGE>
                                                                         ANNEX C
 
                   OPTION GRANTOR/OPTION HOLDER STOCK OPTION
                         AND TRIGGER PAYMENT AGREEMENT
 
    This STOCK OPTION AGREEMENT, dated as of November 10, 1995 (the "AGREEMENT")
by  and among WPL Holdings, Inc., a  corporation organized under the laws of the
State of  Wisconsin ("OPTION  GRANTOR" or  the "COMPANY")  and Interstate  Power
Company,  a  corporation  organized under  the  laws  of the  State  of Delaware
("OPTION HOLDER").
 
                         W I T N E S S E T H  T H A T:
 
    WHEREAS, concurrently with  the execution  and delivery  of this  Agreement,
OPTION  GRANTOR,  OPTION HOLDER,  IES Industries  Inc., a  corporation organized
under  the  laws  of  the  State  of  Iowa  ("IES"),  WPLH  Acquisition  Co.,  a
wholly-owned  subsidiary of OPTION GRANTOR organized under the laws of the State
of Wisconsin  ("ACQUISITION"),  and  Interstate Power  Company,  a  wholly-owned
subsidiary  of OPTION HOLDER organized under the laws of the State of Wisconsin,
are entering into  an Agreement and  Plan of  Merger, dated as  of November  10,
1995,  as amended (the "MERGER AGREEMENT"), which provides, INTER ALIA, upon the
terms and subject to the conditions thereof, for the merger of IES with and into
OPTION GRANTOR in accordance with the laws  of the States of Wisconsin and  Iowa
(the  "IES MERGER"), and the  merger of Acquisition with  and into OPTION HOLDER
(or a successor thereto) in accordance with  the laws of the States of  Delaware
and/or Wisconsin (the "INTERSTATE MERGER", and together with the IES Merger, the
"MERGER");
 
    WHEREAS,  in connection with  the execution of  the Merger Agreement, OPTION
GRANTOR, OPTION HOLDER and IES are entering into certain stock option agreements
dated as of the date hereof, of which this Agreement is one, whereby the parties
hereto grant each other an option with respect to certain shares of each other's
common stock on the terms and subject  to the conditions set forth therein  (the
"STOCK OPTION AGREEMENTS"); and
 
    WHEREAS,  as a  condition to OPTION  HOLDER's willingness to  enter into the
Merger Agreement, OPTION  HOLDER has  requested that OPTION  GRANTOR agree,  and
OPTION  GRANTOR has so agreed, to grant  to OPTION HOLDER an option with respect
to certain shares of OPTION GRANTOR's common stock, on the terms and subject  to
the conditions set forth herein;
 
    NOW,  THEREFORE, to induce OPTION HOLDER  to enter into the Merger Agreement
and certain  of  the  Stock  Option Agreements,  and  in  consideration  of  the
representations,  warranties, covenants and agreements  contained herein, in the
Merger Agreement and in the Stock Option Agreements to which OPTION GRANTOR  and
OPTION  HOLDER are parties,  the parties hereto, intending  to be legally bound,
hereby agree as follows:
 
    1.  GRANT OF OPTION.
 
        (a) Subject  to  the receipt  of  all regulatory  approvals  and  orders
    required  by  OPTION GRANTOR  as  set forth  in  Section 4.4(c)  of  the WPL
    Disclosure Schedule to  the Merger  Agreement and  by OPTION  HOLDER as  set
    forth  in Section 6.4(c) of the Interstate Disclosure Schedule to the Merger
    Agreement, OPTION GRANTOR hereby grants OPTION HOLDER an irrevocable  option
    (the  "OPTION  GRANTOR OPTION")  to purchase  up to  that number  of shares,
    subject to  adjustment  as  provided  in Section  12  (the  "OPTION  GRANTOR
    SHARES"),  of common stock, par value $.01 per share, of OPTION GRANTOR (the
    "OPTION GRANTOR COMMON  STOCK") equal  to a percentage  (the "OPTION  SHARES
    PERCENTAGE"), which Option Shares Percentage is equal to the OPTION HOLDER's
    Participation  Percentage as defined  below in subsection  (e), of 6,123,944
    shares of OPTION GRANTOR Common Stock  (being 19.9% of the number of  shares
    of  OPTION GRANTOR  Common Stock issued  and outstanding as  of November 10,
    1995 (the
 
                                      C-1
<PAGE>
    "INITIAL NUMBER") in the manner set  forth below, at a price (the  "EXERCISE
    PRICE")  per OPTION  GRANTOR Share  of $30.675 (which  is equal  to the Fair
    Market Value (as defined below)  of an OPTION GRANTOR  Share as of the  date
    hereof).
 
        (b)  The Exercise Price shall be  payable, at OPTION HOLDER's option, as
    follows:
 
           (i) in cash, or
 
           (ii) subject  to the  receipt of  all approvals  of any  Governmental
       Authority  required for OPTION  GRANTOR to acquire,  and OPTION HOLDER to
       issue, the OPTION HOLDER Shares (as defined below) from OPTION HOLDER, in
       shares of common stock, $3.50 par value, of OPTION HOLDER ("OPTION HOLDER
       SHARES"),
 
    in either case in accordance with Section 4 hereof.
 
        (c) Notwithstanding  the foregoing,  in  no event  shall the  number  of
    OPTION  GRANTOR Shares  for which the  OPTION GRANTOR  Option is exercisable
    exceed the product of the Option  Shares Percentage and the Initial  Number,
    subject to adjustment as provided in Section 12.
 
        (d)  As used herein, the  "FAIR MARKET VALUE" of  any share shall be the
    average of the  daily closing sales  price for  such share on  the New  York
    Stock  Exchange (the "NYSE") during  the ten NYSE trading  days prior to the
    fifth NYSE trading day preceding  the date such Fair  Market Value is to  be
    determined.
 
        (e)  For purposes of this  Agreement the term "PARTICIPATION PERCENTAGE"
    shall have  the  same  meaning  as  in  Section  10.3(f)(i)  of  the  Merger
    Agreement,  except that  the numerator  and denominator  shall be calculated
    based on the number of  shares of WPL Common  Stock which would be  issuable
    (or,  in the case of  WPL, retained by its  shareholders) on a fully diluted
    basis had the Effective Time occurred as  of the date on which the  Exercise
    Notice  is delivered under Section 2 hereof  or the date on which demand for
    the Trigger Payment (as defined herein) is given under Section 5 hereof,  as
    the  case may be. Other capitalized terms used herein but not defined herein
    shall have the meanings set forth in the Merger Agreement.
 
    2.  EXERCISE OF OPTION.
 
        (a) The OPTION  GRANTOR Option  may be  exercised by  OPTION HOLDER,  in
    whole  or  in part,  at  any time  or  from time  to  time after  the Merger
    Agreement becomes  terminable by  OPTION  HOLDER under  circumstances  which
    could  entitle OPTION HOLDER  to a termination fee  under Section 10.3(a) of
    the  Merger  Agreement  (provided  that  the  events  specified  in  Section
    10.3(a)(ii)(A)  of the  Merger Agreement  shall have  occurred, although the
    events specified in Section 10.3(a)(ii)(B) thereof need not have  occurred),
    or Section 10.3(b) of the Merger Agreement (regardless of whether the Merger
    Agreement  is actually terminated  or whether there occurs  a closing of any
    Business Combination involving a Target Party or a closing by which a Target
    Party becomes a Subsidiary),  any such event by  which the Merger  Agreement
    becomes  so  terminable  by OPTION  HOLDER  being  referred to  herein  as a
    "TRIGGER EVENT").
 
        (b) (i) OPTION GRANTOR shall notify OPTION HOLDER promptly in writing of
    the occurrence of any Trigger Event, it being understood that the giving  of
    such  notice by  OPTION GRANTOR  shall not  be a  condition to  the right of
    OPTION HOLDER to exercise the OPTION GRANTOR Option.
 
           (ii) In the event OPTION HOLDER wishes to exercise the OPTION GRANTOR
       Option, OPTION HOLDER shall deliver to OPTION GRANTOR written notice  (an
       "EXERCISE  NOTICE") specifying the total  number of OPTION GRANTOR Shares
       it wishes to purchase.
 
          (iii) Upon  the giving  by  OPTION HOLDER  to  OPTION GRANTOR  of  the
       Exercise  Notice  and the  tender  of the  applicable  aggregate Exercise
       Price, OPTION HOLDER, to the extent permitted by law and OPTION GRANTOR's
       organizational documents,  and provided  that  the conditions  to  OPTION
       GRANTOR's obligation to issue the OPTION GRANTOR
 
                                      C-2
<PAGE>
       Shares  to  OPTION HOLDER  hereunder  set forth  in  Section 3  have been
       satisfied or waived, shall be  deemed to be the  holder of record of  the
       OPTION  GRANTOR Shares issuable upon  such exercise, notwithstanding that
       the stock transfer books of OPTION  GRANTOR shall then be closed or  that
       certificates  representing such OPTION  GRANTOR Shares shall  not then be
       actually delivered to OPTION HOLDER.
 
          (iv) Each closing of a purchase of OPTION GRANTOR Shares (a "CLOSING")
       shall occur at a  place, on a  date, and at a  time designated by  OPTION
       HOLDER  in an Exercise Notice delivered  at least two business days prior
       to the date of the Closing.
 
        (c) The OPTION GRANTOR Option shall terminate upon the earliest to occur
    of:
 
           (i) the Effective Time of the Merger;
 
           (ii) the termination of the Merger Agreement pursuant to Section 10.1
       thereof, other than under circumstances  which also constitute a  Trigger
       Event under this Agreement;
 
          (iii)  180 days following any termination of the Merger Agreement upon
       or during the continuance of a Trigger Event (or if, at the expiration of
       such 180 day  period, the OPTION  GRANTOR Option cannot  be exercised  by
       reason  of any applicable judgment, decree, order, law or regulation, ten
       business days after such impediment  to exercise shall have been  removed
       or  shall have become  final and not  subject to appeal,  but in no event
       under this clause (iii) later than May 10, 1998); and
 
          (iv) payment by  OPTION GRANTOR of  the Trigger Payment  set forth  in
       Section 5 of this Agreement to OPTION HOLDER.
 
        (d)  Notwithstanding the foregoing, the OPTION GRANTOR Option may not be
    exercised if  (i)  OPTION  HOLDER  is  in material  breach  of  any  of  its
    representations or warranties, or in material breach of any of its covenants
    or  agreements, contained in  this Agreement or in  the Merger Agreement, or
    (ii) a Trigger Payment has been paid pursuant to Section 5 of this Agreement
    or demand therefor has been made and not withdrawn.
 
    3.  CONDITIONS TO CLOSING.   The obligation of  OPTION GRANTOR to issue  the
OPTION  GRANTOR Shares to  OPTION HOLDER hereunder is  subject to the conditions
that
 
        (a) all waiting  periods, if any,  under the HSR  Act applicable to  the
    issuance  and acquisition of the OPTION  GRANTOR Shares hereunder shall have
    expired or have been terminated;
 
        (b) the OPTION GRANTOR  Shares, and any OPTION  HOLDER Shares which  are
    issued  in  payment of  the  Exercise Price,  shall  have been  approved for
    listing on the NYSE subject only to official notice of issuance;
 
        (c)  all   consents,  approvals,   orders  or   authorizations  of,   or
    registrations,  declarations or  filings with,  any federal,  state or local
    administrative agency  or  commission  or  other  federal,  state  or  local
    Governmental  Authority, if any, required in connection with the issuance by
    OPTION GRANTOR and the  acquisition by OPTION HOLDER  of the OPTION  GRANTOR
    Shares  hereunder  shall  have  been obtained  or  made,  including, without
    limitation, the approval of the  SEC under Sections 9  and 10 of the  Public
    Utility  Holding  Company Act  of  1935, as  amended  (the "1935  ACT"), the
    approval of the Public  Service Commission of Wisconsin  of the issuance  of
    the  OPTION  GRANTOR  Shares  by  OPTION  GRANTOR  and,  if  applicable, the
    acquisition of OPTION GRANTOR Shares by  OPTION HOLDER, and the approval  of
    the  Iowa Utilities Board, the Minnesota Public Utilities Commission and the
    Illinois Commerce Commission of the acquisition of the OPTION GRANTOR Shares
    by OPTION HOLDER and,  if applicable, the acquisition  by OPTION GRANTOR  of
    the OPTION HOLDER Shares constituting the Exercise Price hereunder; and
 
                                      C-3
<PAGE>
        (d)  no preliminary or permanent injunction  or other order by any court
    of competent jurisdiction prohibiting or otherwise restraining such issuance
    shall be in effect.
 
The condition set forth in paragraph (b) above may be waived by OPTION  GRANTOR,
in the case of OPTION HOLDER Shares, and by OPTION HOLDER, in the case of OPTION
GRANTOR Shares, in the sole discretion of the waiving party.
 
    4.  CLOSING. At any Closing,
 
        (a)  OPTION GRANTOR  shall deliver  to OPTION  HOLDER or  its designee a
    single certificate  in definitive  form representing  the number  of  OPTION
    GRANTOR  Shares designated  by OPTION  HOLDER in  its Exercise  Notice, such
    certificate to be registered in  the name of OPTION  HOLDER and to bear  the
    legend set forth in Section 13; and
 
        (b)  OPTION HOLDER shall  deliver to OPTION  GRANTOR the aggregate price
    for the OPTION GRANTOR Shares so designated and being purchased by
 
           (i) wire transfer of immediately  available funds or certified  check
       or bank check, or
 
           (ii)  subject to  the condition  in Section  1(b)(ii), delivery  of a
       certificate or  certificates representing  the  number of  OPTION  HOLDER
       Shares being issued by OPTION HOLDER in consideration thereof, determined
       in accordance with Section 4(c).
 
        (c)  In  the event  that OPTION  HOLDER issues  OPTION HOLDER  Shares to
    OPTION GRANTOR in consideration of OPTION GRANTOR Shares pursuant to Section
    4(b)(ii), the number of OPTION HOLDER Shares to be so issued shall be  equal
    to the quotient obtained by dividing:
 
           (i)  the  product of  (x) the  number of  OPTION GRANTOR  Shares with
       respect to which the OPTION GRANTOR Option is being exercised and (y) the
       Exercise Price, by
 
           (ii) the Fair Market Value of the OPTION HOLDER Shares as of the date
       immediately preceding the date the Exercise Notice is delivered to OPTION
       GRANTOR.
 
        (d) OPTION GRANTOR  shall pay  all expenses,  and any  and all  Federal,
    state  and local taxes and  other charges that may  be payable in connection
    with the preparation, issue  and delivery of  stock certificates under  this
    Section 4.
 
    5.  TRIGGER PAYMENT.
 
        (a)   TRIGGER PAYMENT.  Subject to  the provisions of Section 10.3(e) of
    the Merger  Agreement,  if a  Trigger  Event  shall have  occurred  and  any
    regulatory approval or order required for the issuance by OPTION GRANTOR, or
    the  acquisition by OPTION HOLDER, of  the OPTION GRANTOR Option pursuant to
    Section 1 hereof shall not have been obtained, OPTION HOLDER shall have  the
    right  to receive, and OPTION GRANTOR shall  pay to OPTION HOLDER, an amount
    (the "TRIGGER PAYMENT") equal to the product of
 
           (i) the maximum number of OPTION GRANTOR Shares that would have  been
       subject  to purchase by OPTION HOLDER upon exercise of the OPTION GRANTOR
       Option pursuant  to  Sections 1  and  2  hereof if  all  such  regulatory
       approvals or orders had been obtained, and
 
           (ii)  the difference between  (A) the Market/Offer  Price (as defined
       herein), determined as  of the  date on which  notice of  demand for  the
       Trigger  Payment is  given by OPTION  HOLDER, and (B)  the Exercise Price
       (but only if such Market/Offer Price is higher than such Exercise Price).
 
    Demand for the Trigger Payment shall  be given by notice in accordance  with
    the  provisions of Section 17  hereof. The Trigger Payment  shall be paid to
    OPTION HOLDER by OPTION
 
                                      C-4
<PAGE>
    GRANTOR on  the  Payment Date  (as  defined  herein), by  wire  transfer  of
    immediately  available funds  to an account  to be designated  in writing by
    OPTION HOLDER not less than two business days before the Payment Date.
 
        (b)  PAYMENT DATE.  For purposes of this Section 5, "PAYMENT DATE" means
    the date on which termination fees are required to be paid by OPTION GRANTOR
    to OPTION HOLDER under Section  10.3(a) or 10.3(b), as  the case may be,  of
    the  Merger Agreement  as a  result of the  occurrence of  the Trigger Event
    referred to in subsection (a) of this Section 5.
 
        (c)  CERTAIN CONDITIONS.  OPTION GRANTOR shall have no obligation to pay
    the Trigger Payment if  OPTION HOLDER is  in material breach  of any of  its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in this Agreement or in the Merger Agreement.
 
    6.    REPRESENTATIONS  AND WARRANTIES  OF  OPTION GRANTOR.    OPTION GRANTOR
represents and warrants to OPTION HOLDER that
 
        (a) except as set forth in Section 4.4(a) of the WPL Disclosure Schedule
    to the  Merger  Agreement,  OPTION  GRANTOR  has  the  corporate  power  and
    authority  to enter  into this  Agreement and  to carry  out its obligations
    hereunder, subject  in the  case of  the repurchase  of the  OPTION  GRANTOR
    Shares  pursuant to  Section 8(a)  to applicable  law and  the provisions of
    OPTION GRANTOR's Articles of Incorporation, as amended (the "OPTION  GRANTOR
    ARTICLES");
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION GRANTOR, and, assuming the due authorization, execution and  delivery
    hereof  by  OPTION  HOLDER  and  the  receipt  of  all  required  regulatory
    approvals, constitutes a  valid and  binding obligation  of OPTION  GRANTOR,
    enforceable  against OPTION GRANTOR in accordance  with its terms, except as
    may be limited by applicable bankruptcy, insolvency, reorganization or other
    similar laws affecting the enforcement  of creditors' rights generally,  and
    except  that  the  availability of  equitable  remedies,  including specific
    performance, may be subject to the discretion of any court before which  any
    proceeding therefor may be brought;
 
        (c) OPTION GRANTOR has taken all necessary corporate action to authorize
    and  reserve for issuance  and to permit  it to issue,  upon exercise of the
    OPTION GRANTOR Option,  and at all  times from the  date hereof through  the
    expiration  of the  OPTION GRANTOR  Option will  have reserved,  the Initial
    Number of authorized and unissued  OPTION GRANTOR Shares, such amount  being
    subject  to adjustment as provided  in Section 12, all  of which, upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be  duly authorized, validly issued, fully paid and nonassessable (except as
    otherwise provided in Section 180.0622(2)(b) of the WBCL);
 
        (d) upon delivery of the OPTION GRANTOR Shares to OPTION HOLDER upon the
    exercise of the OPTION GRANTOR Option, OPTION HOLDER will acquire the OPTION
    GRANTOR Shares free and  clear of all  claims, liens, charges,  encumbrances
    and security interests of any nature whatsoever;
 
        (e) except as described in Section 4.4(b) of the WPL Disclosure Schedule
    to  the Merger  Agreement, the execution  and delivery of  this Agreement by
    OPTION GRANTOR does not, and, subject to compliance with applicable law  and
    the  OPTION GRANTOR  Articles with respect  to the repurchase  of the OPTION
    GRANTOR Shares pursuant to Section 8(a), the consummation by OPTION  GRANTOR
    of  the transactions contemplated hereby will not violate, conflict with, or
    result in a breach  of any provision  of, or constitute  a default (with  or
    without  notice  or  a lapse  of  time, or  both)  under, or  result  in the
    termination of, or accelerate  the performance required by,  or result in  a
    right of termination, cancellation, or acceleration of any obligation or the
    loss  of  a material  benefit  under, or  the  creation of  a  lien, pledge,
    security interest or other encumbrance on
 
                                      C-5
<PAGE>
    assets  (any  such  conflict,  violation,  default,  right  of  termination,
    cancellation,  acceleration, loss or creation, hereinafter a "VIOLATION") of
    OPTION GRANTOR or any of its Subsidiaries, pursuant to
 
           (i) any provision  of the OPTION  GRANTOR Articles or  the Bylaws  of
       OPTION GRANTOR,
 
           (ii)  any provisions of any material  loan or credit agreement, note,
       mortgage, indenture, lease, benefit plan or other agreement,  obligation,
       instrument,   permit,  concession,  franchise  or  license  (any  of  the
       foregoing in effect on the date  hereof being referred to as a  "MATERIAL
       CONTRACT")  of OPTION GRANTOR or its subsidiaries or to which any of them
       is a party, or
 
          (iii) any judgment,  order, decree, statute,  law, ordinance, rule  or
       regulation applicable to OPTION GRANTOR or its properties or assets,
 
    which  Violation,  in  the  case  of  each  clauses  (ii)  and  (iii), could
    reasonably be expected  to have  an OPTION GRANTOR  Material Adverse  Effect
    (except that no representation or warranty is given concerning any Violation
    of  a Material  Contract with  respect to  the repurchase  of OPTION GRANTOR
    Shares pursuant to Section 8(a));
 
        (f) except as described in Section 4.4(c) of the WPL Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of this Agreement by  OPTION GRANTOR does not,  and the performance of  this
    Agreement  by  OPTION  GRANTOR  will  not,  require  any  consent, approval,
    authorization or permit of, filing with or notification to, any Governmental
    Authority;
 
        (g) none of OPTION  GRANTOR, any of its  affiliates or anyone acting  on
    its  or their  behalf, has  issued, sold or  offered any  security of OPTION
    GRANTOR to any person under circumstances that would cause the issuance  and
    sale  of OPTION  GRANTOR Shares,  as contemplated  by this  Agreement, to be
    subject to the registration requirements of the Securities Act as in  effect
    on  the date  hereof, and,  assuming the  representations and  warranties of
    OPTION HOLDER contained in Section 7(g) are true and correct, the  issuance,
    sale  and delivery  of the OPTION  GRANTOR Shares hereunder  would be exempt
    from the registration and prospectus delivery requirements of the Securities
    Act, as in effect on the date hereof (and OPTION GRANTOR shall not take  any
    action  which would cause the issuance, sale, and delivery of OPTION GRANTOR
    Shares hereunder not to be exempt from such requirements); and
 
        (h) any OPTION HOLDER Shares acquired pursuant to this Agreement will be
    acquired for OPTION GRANTOR's own account, for investment purposes only, and
    will  not  be  acquired  by  OPTION  GRANTOR  with  a  view  to  the  public
    distribution  thereof  in  violation  of  any  applicable  provision  of the
    Securities Act.
 
    7.   REPRESENTATIONS  AND  WARRANTIES  OF  OPTION  HOLDER.    OPTION  HOLDER
represents and warrants to OPTION GRANTOR that
 
        (a)  except as set forth in Schedule 6.4(a) of the Interstate Disclosure
    Schedule to the Merger Agreement, OPTION HOLDER has the corporate power  and
    authority  to enter  into this  Agreement and  to carry  out its obligations
    hereunder;
 
        (b) this Agreement has been duly  and validly executed and delivered  by
    OPTION  HOLDER and, assuming  the due authorization,  execution and delivery
    hereof by  OPTION  GRANTOR  and  the  receipt  of  all  required  regulatory
    approvals,  constitutes  a valid  and binding  obligation of  OPTION HOLDER,
    enforceable against OPTION HOLDER in  accordance with its respective  terms,
    except   as   may   be  limited   by   applicable   bankruptcy,  insolvency,
    reorganization,  or  other  similar   laws  affecting  the  enforcement   of
    creditors'  rights generally, and except  that the availability of equitable
    remedies, including specific performance, may  be subject to the  discretion
    of any court before which any proceeding may be brought;
 
                                      C-6
<PAGE>
        (c)  prior to any  delivery of OPTION HOLDER  Shares in consideration of
    the purchase of OPTION  GRANTOR Shares pursuant  hereto, OPTION HOLDER  will
    have  taken all necessary corporate action  to authorize for issuance and to
    permit it  to issue  such OPTION  HOLDER Shares,  all of  which, upon  their
    issuance  and delivery in accordance with  the terms of this Agreement, will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d) upon any delivery of such OPTION HOLDER Shares to OPTION GRANTOR  in
    consideration  of  the purchase  of OPTION  GRANTOR Shares  pursuant hereto,
    OPTION GRANTOR will acquire the OPTION  HOLDER Shares free and clear of  all
    claims,  liens, charges, encumbrances  and security interests  of any nature
    whatsoever;
 
        (e) except as described in  Section 6.4(b) of the Interstate  Disclosure
    Schedule  to  the  Merger  Agreement, the  execution  and  delivery  of this
    Agreement by OPTION HOLDER does not,  and the consummation by OPTION  HOLDER
    of the transactions contemplated hereby will not, violate, conflict with, or
    result  in the breach of any provision  of, or constitute a default (with or
    without notice  or  a lapse  of  time, or  both)  under, or  result  in  any
    Violation by OPTION HOLDER or any of its Subsidiaries, pursuant to
 
           (i)  any  provision of  the Articles  of  Incorporation or  Bylaws of
       OPTION HOLDER,
 
           (ii)  any  Material  Contract  of   OPTION  HOLDER  or  any  of   its
       subsidiaries or to which any of them is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable to OPTION HOLDER or its properties or assets,
 
    which Violation, in the case of each of clauses (ii) or (iii), would have an
    OPTION HOLDER Material Adverse Effect;
 
        (f) except as described in  Section 6.4(c) of the Interstate  Disclosure
    Schedule to the Merger Agreement or Section 1 or 3 hereof, the execution and
    delivery  of this Agreement by OPTION  HOLDER does not, and the consummation
    by OPTION HOLDER of the  transactions contemplated hereby will not,  require
    any   consent,  approval,  authorization  or   permit  of,  filing  with  or
    notification to, any Governmental Authority; and
 
        (g) any  OPTION GRANTOR  Shares  acquired upon  exercise of  the  OPTION
    GRANTOR  Option  will  be  acquired for  OPTION  HOLDER's  own  account, for
    investment purposes only and will not  be, and the OPTION GRANTOR Option  is
    not  being, acquired by OPTION HOLDER with a view to the public distribution
    thereof, in violation of any applicable provision of the Securities Act.
 
    8.  CERTAIN REPURCHASES.
 
        (a)  OPTION HOLDER "PUT".   At the request  of OPTION HOLDER by  written
    notice (x) at any time during which the OPTION GRANTOR Option is exercisable
    pursuant  to Section  2 (the  "REPURCHASE PERIOD"),  OPTION GRANTOR  (or any
    successor entity thereof) shall, if permitted by applicable law, the  OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase from  OPTION HOLDER  all or  any portion  of the  OPTION  GRANTOR
    Option,  at the price  set forth in  subparagraph (i) below,  or, (y) at any
    time prior to May 10, 1997 (provided that such date shall be extended to May
    10, 1998 under the circumstances where the date after which either party may
    terminate the Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger
    Agreement  has  been  extended to  May  10,  1998), OPTION  GRANTOR  (or any
    successor entity  thereof)  shall,  if  permitted  by  applicable  law,  the
 
                                      C-7
<PAGE>
    OPTION  GRANTOR Articles and Bylaws and OPTION GRANTOR's Material Contracts,
    repurchase from  OPTION HOLDER  all or  any portion  of the  OPTION  GRANTOR
    Shares  purchased by OPTION HOLDER pursuant to the OPTION GRANTOR Option, at
    the price set forth in subparagraph (ii) below:
 
           (i) (A) The difference between  the "Market/Offer Price" (as  defined
       below)  for shares of OPTION  GRANTOR Common Stock as  of the date OPTION
       HOLDER gives  notice of  its intent  to exercise  its rights  under  this
       Section  8 and  the Exercise  Price, multiplied  by the  number of OPTION
       GRANTOR Shares  purchasable pursuant  to the  OPTION GRANTOR  Option  (or
       portion  thereof with  respect to which  OPTION HOLDER  is exercising its
       rights under  this Section  8), but  only if  the Market/Offer  Price  is
       greater than the Exercise Price.
 
               (B)  For purposes  of this Agreement,  "MARKET/OFFER PRICE" shall
       mean, as of any date, the higher of (I) the price per share offered as of
       such date pursuant to  any tender or exchange  offer or other offer  with
       respect  to a Business Combination involving OPTION GRANTOR as the Target
       Party which was made prior to  such date and not terminated or  withdrawn
       as  of such date and (II) the  Fair Market Value of OPTION GRANTOR Common
       Stock as of such date.
 
           (ii) (A) The product of (I) the sum of (a) the Exercise Price paid by
       OPTION HOLDER per OPTION  GRANTOR Share acquired  pursuant to the  OPTION
       GRANTOR  Option, and  (b) the  difference between  the "Offer  Price" (as
       defined below) and  the Exercise Price,  but only if  the Offer Price  is
       greater  than the Exercise  Price, and (II) the  number of OPTION GRANTOR
       Shares so to be repurchased pursuant to this Section 8.
 
               (B) For purposes of this clause (ii), the "OFFER PRICE" shall  be
       the  highest price  per share  offered pursuant  to a  tender or exchange
       offer or other Business Combination offer involving OPTION GRANTOR as the
       Target Party during the Repurchase Period prior to the delivery by OPTION
       HOLDER of a notice of repurchase.
 
        (b)  REDELIVERY OF  OPTION HOLDER SHARES.   If OPTION HOLDER shall  have
    previously  elected  to  purchase  OPTION  GRANTOR  Shares  pursuant  to the
    exercise of the OPTION GRANTOR Option by the issuance and delivery of OPTION
    HOLDER Shares, then OPTION GRANTOR shall, if so requested by OPTION  HOLDER,
    in  fulfillment of its obligation pursuant to Section 8(a)(y) (that is, with
    respect to the Exercise Price only and without limitation to its  obligation
    to pay additional consideration under clause (b) of Section 8(a)(ii)(A)(I)),
    redeliver  the certificates for such OPTION  HOLDER Shares to OPTION HOLDER,
    free and clear of all liens, claims, charges and encumbrances of any kind or
    nature whatsoever; PROVIDED, HOWEVER, that if  at any time less than all  of
    the  OPTION GRANTOR  Shares so  purchased by  OPTION HOLDER  pursuant to the
    OPTION GRANTOR Option are  to be repurchased by  OPTION GRANTOR pursuant  to
    Section  8(a)(y), then (i) OPTION GRANTOR shall be obligated to redeliver to
    OPTION HOLDER the same proportion of such OPTION HOLDER Shares as the number
    of OPTION GRANTOR Shares that OPTION GRANTOR is then obligated to repurchase
    bears to the number of OPTION GRANTOR Shares acquired by OPTION HOLDER  upon
    exercise  of the OPTION GRANTOR Option and (ii) OPTION HOLDER shall issue to
    OPTION GRANTOR  new certificates  representing  those OPTION  HOLDER  Shares
    which  are  not due  to be  redelivered  to OPTION  HOLDER pursuant  to this
    Section 8(b) to the extent that excess OPTION HOLDER Shares are included  in
    the certificates redelivered to OPTION HOLDER by OPTION GRANTOR.
 
        (c)   PAYMENT AND REDELIVERY OF OPTION GRANTOR OPTIONS OR SHARES. In the
    event OPTION  HOLDER  exercises its  rights  under this  Section  8,  OPTION
    GRANTOR  shall, within ten business days thereafter, pay the required amount
    to OPTION  HOLDER in  immediately available  funds and  OPTION HOLDER  shall
    surrender  to OPTION GRANTOR the OPTION GRANTOR Option or the certificate or
    certificates evidencing the OPTION GRANTOR Shares purchased by OPTION HOLDER
    pursuant hereto, and OPTION HOLDER shall warrant
 
                                      C-8
<PAGE>
    that it owns the OPTION  GRANTOR Option or such  shares and that the  OPTION
    GRANTOR  Option or such shares are then free and clear of all liens, claims,
    damages, charges and encumbrances of any kind or nature whatsoever.
 
        (d)  OPTION  HOLDER "CALL".   If OPTION HOLDER  has elected to  purchase
    OPTION  GRANTOR Shares pursuant to the exercise of the OPTION GRANTOR Option
    by the issuance and delivery  of OPTION HOLDER Shares, notwithstanding  that
    OPTION  HOLDER may  no longer  hold any such  OPTION GRANTOR  Shares or that
    OPTION HOLDER elects not to exercise its other rights under this Section  8,
    OPTION HOLDER may require, at any time or from time to time prior to May 10,
    1997  (provided that such date  shall be extended to  May 10, 1998 under the
    circumstances where  the date  after which  either party  may terminate  the
    Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger Agreement has
    been extended to May 10, 1998), OPTION GRANTOR to sell to OPTION HOLDER  any
    such  OPTION HOLDER  Shares at  the price  attributed to  such OPTION HOLDER
    Shares pursuant to Section 4 plus interest at the rate of 8.75% per annum on
    such amount from the  Closing Date relating to  the exchange of such  OPTION
    HOLDER  Shares pursuant to Section 4 to  the Closing Date under this Section
    8(d) less any dividends on such OPTION HOLDER Shares paid during such period
    or declared and  payable to  stockholders of record  on a  date during  such
    period.
 
        (e)   REPURCHASE PRICE REDUCED AT OPTION  HOLDER'S OPTION.  In the event
    the repurchase price specified in Section 8(a) would subject the purchase of
    the OPTION GRANTOR Option or the  OPTION GRANTOR Shares purchased by  OPTION
    HOLDER  pursuant to the OPTION GRANTOR Option  to a vote of the shareholders
    of OPTION GRANTOR pursuant to applicable law or the OPTION GRANTOR Articles,
    then OPTION HOLDER may, at its  election, reduce the repurchase price to  an
    amount  which would permit such repurchase  without the necessity for such a
    shareholder vote.
 
    9.  VOTING  OF SHARES.   Following the date  hereof and prior  to the  fifth
anniversary  of the date  hereof (the "EXPIRATION DATE"),  each party shall vote
any shares of capital stock of the  other party acquired by such party  pursuant
to  this  Agreement ("RESTRICTED  SHARES"), including  any OPTION  HOLDER Shares
issued pursuant to  Section 1(b),  or otherwise beneficially  owned (within  the
meaning  of Rule 13d-3 promulgated under the Securities Exchange Act of 1934, as
amended (the "EXCHANGE ACT")), by such party on each matter submitted to a  vote
of  shareholders of  such other party  for and  against such matter  in the same
proportion as the vote of all other  shareholders of such other party are  voted
(whether by proxy or otherwise) for and against such matter.
 
    10.  RESTRICTIONS ON TRANSFER.
 
        (a)   RESTRICTIONS ON  TRANSFER.  Prior to  the Expiration Date, neither
    party shall, directly or indirectly, by operation of law or otherwise, sell,
    assign, pledge, or otherwise  dispose of or  transfer any Restricted  Shares
    beneficially  owned by such party, other than  (i) pursuant to Section 8, or
    (ii) in accordance with Section 10(b) or Section 11.
 
        (b)    PERMITTED  SALES.    Following  the  termination  of  the  Merger
    Agreement,  a  party  shall  be  permitted  to  sell  any  Restricted Shares
    beneficially owned  by it  if such  sale is  made pursuant  to a  tender  or
    exchange   offer  that  has  been  approved  or  recommended,  or  otherwise
    determined to be fair to  and in the best  interests of the shareholders  of
    the  other party, by a majority of the  members of the Board of Directors of
    such other party, which majority shall  include a majority of directors  who
    were directors prior to the announcement of such tender or exchange offer.
 
    11.  REGISTRATION RIGHTS.
 
        (a)  Following  the termination  of the  Merger Agreement,  either party
    hereto that owns Restricted  Shares (a "DESIGNATED  HOLDER") may by  written
    notice  (the "REGISTRATION  NOTICE") to  the other  party (the "REGISTRANT")
    request  the  Registrant   to  register   under  the   Securities  Act   all
 
                                      C-9
<PAGE>
    or  any part of the Restricted  Shares beneficially owned by such Designated
    Holder  (the  "REGISTRABLE  SECURITIES")  pursuant  to  a  bona  fide   firm
    commitment  underwritten public offering, in which the Designated Holder and
    the underwriters shall  effect as  wide a distribution  of such  Registrable
    Securities  as is reasonably practicable and shall use their best efforts to
    prevent any person  (including any Group  (as used in  Rule 13d-5 under  the
    Exchange  Act))  and its  affiliates from  purchasing through  such offering
    Restricted Shares representing  more than  1% of the  outstanding shares  of
    common  stock  of the  Registrant  on a  fully  diluted basis  (a "PERMITTED
    OFFERING").
 
        (b) The Registration Notice shall include a certificate executed by  the
    Designated  Holder and its proposed  managing underwriter, which underwriter
    shall be an investment banking  firm of nationally recognized standing  (the
    "MANAGER"), stating that
 
           (i) they have a good faith intention to commence promptly a Permitted
       Offering, and
 
           (ii)   the  manager  in  good  faith  believes  that,  based  on  the
       then-prevailing  market  conditions,  it  will   be  able  to  sell   the
       Registrable  Securities at a per share price equal to at least 80% of the
       then Fair Market Value of such shares.
 
        (c) The  Registrant (and/or  any person  designated by  the  Registrant)
    shall  thereupon have the option exercisable  by written notice delivered to
    the Designated Holder  within ten  business days  after the  receipt of  the
    Registration Notice, irrevocably to agree to purchase all or any part of the
    Registrable  Securities proposed  to be  so sold  for cash  at a  price (the
    "OPTION PRICE")  equal to  the  product of  (i)  the number  of  Registrable
    Securities  to be  so purchased  by the  Registrant and  (ii) the  then Fair
    Market Value of such shares.
 
        (d) Any purchase  of Registrable  Securities by the  Registrant (or  its
    designee)  under Section 11(c) shall  take place at a  closing to be held at
    the principal executive offices of the  Registrant or at the offices of  its
    counsel  at any reasonable date and time designated by the Registrant and/or
    such designee in such notice within  twenty business days after delivery  of
    such notice, and any payment for the shares to be so purchased shall be made
    by delivery at the time of such closing in immediately available funds.
 
        (e)  If the Registrant does not elect to exercise its option pursuant to
    this Section 11 with respect to all Registrable Securities, it shall use its
    best efforts to effect, as  promptly as practicable, the registration  under
    the  Securities Act of the unpurchased Registrable Securities proposed to be
    so sold; PROVIDED, HOWEVER, that
 
           (i) neither party shall be entitled to demand more than an  aggregate
       of two effective registration statements hereunder, and
 
           (ii)   the  Registrant  will  not  be   required  to  file  any  such
       registration statement during any period of  time (not to exceed 40  days
       after such request in the case of clause (A) below or 90 days in the case
       of clauses (B) and (C) below) when
 
               (A)  the  Registrant  is  in  possession  of  material non-public
           information which it reasonably believes  would be detrimental to  be
           disclosed  at  such  time  and,  in the  opinion  of  counsel  to the
           Registrant, such information would be  required to be disclosed if  a
           registration statement were filed at that time;
 
               (B)  the  Registrant  is  required under  the  Securities  Act to
           include  audited  financial  statements   for  any  period  in   such
           registration  statement  and such  financial  statements are  not yet
           available for inclusion in such registration statement; or
 
               (C) the Registrant determines,  in its reasonable judgment,  that
           such  registration would interfere with any financing, acquisition or
           other material transaction  involving the  Registrant or  any of  its
           affiliates.
 
        (f)  The Registrant shall  use its reasonable best  efforts to cause any
    Registrable  Securities  registered  pursuant  to  this  Section  11  to  be
    qualified    for   sale   under   the    securities   or   Blue   Sky   laws
 
                                      C-10
<PAGE>
    of such jurisdictions as  the Designated Holder  may reasonably request  and
    shall  continue  such  registration  or  qualification  in  effect  in  such
    jurisdiction; PROVIDED, HOWEVER, that the  Registrant shall not be  required
    to  qualify to do business in, or  consent to general service of process in,
    any jurisdiction by reason of this provision.
 
        (g) The registration rights set forth in this Section 11 are subject  to
    the  condition that the Designated Holder  shall provide the Registrant with
    such information with respect to  such holder's Registrable Securities,  the
    plans  for the distribution thereof, and such other information with respect
    to such holder as, in the reasonable judgment of counsel for the Registrant,
    is necessary  to  enable the  Registrant  to include  in  such  registration
    statement  all material  facts required  to be  disclosed with  respect to a
    registration thereunder.
 
        (h) A registration effected under this  Section 11 shall be effected  at
    the  Registrant's expense, except for underwriting discounts and commissions
    and the fees and the expenses of  counsel to the Designated Holder, and  the
    Registrant  shall provide to the  underwriters such documentation (including
    certificates, opinions of counsel and "comfort" letters from auditors) as is
    customary  in  connection  with   underwritten  public  offerings  as   such
    underwriters may reasonably require.
 
        (i)  In connection with any registration effected under this Section 11,
    the parties agree
 
           (i) to indemnify  each other  and the underwriters  in the  customary
       manner,
 
           (ii)  to enter into  an underwriting agreement  in form and substance
       customary for transactions of  such type with the  Manager and the  other
       underwriters participating in such offering, and
 
          (iii)  to take all further actions which shall be reasonably necessary
       to effect such registration and sale  (including if the Manager deems  it
       necessary, participating in road-show presentations).
 
        (j)    The Registrant  shall  be entitled  to  include (at  its expense)
    additional shares of its common stock in a registration effected pursuant to
    this Section 11 only if and to  the extent the Manager determines that  such
    inclusion  will  not  adversely affect  the  prospects for  success  of such
    offering.
 
    12.  ADJUSTMENT UPON CHANGES IN  CAPITALIZATION.  Without limitation to  any
restriction  on  OPTION GRANTOR  contained in  this Agreement  or in  the Merger
Agreement, in the event of any change  in OPTION GRANTOR Common Stock by  reason
of    stock   dividends,   splitups,   mergers    (other   than   the   Merger),
recapitalizations, combinations, exchange of  shares or the  like, the type  and
number  of shares or  securities subject to  the OPTION GRANTOR  Option, and the
purchase price per share provided in Section 1, shall be adjusted  appropriately
to  restore  to  OPTION HOLDER  its  rights  hereunder, including  the  right to
purchase from OPTION GRANTOR (or its successors) shares of OPTION GRANTOR Common
Stock (or such other shares or securities into which OPTION GRANTOR Common Stock
has been so changed)  representing the Option Shares  Percentage of the  Initial
Number of shares of OPTION GRANTOR Common Stock for the aggregate Exercise Price
calculated as of the date of this Agreement as provided in Section 1.
 
    13.    RESTRICTIVE LEGENDS.   Each  certificate representing  OPTION GRANTOR
Shares issued to  OPTION HOLDER  hereunder, and  OPTION HOLDER  Shares, if  any,
delivered   to  OPTION  GRANTOR  at  a   Closing,  shall  include  a  legend  in
substantially the following form:
 
    THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN  REGISTERED
    UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES OR
    BLUE  SKY LAWS, AND MAY BE REOFFERED OR SOLD ONLY IF SO REGISTERED OR IF
    AN EXEMPTION FROM  SUCH REGISTRATION IS  AVAILABLE. SUCH SECURITIES  ARE
    ALSO SUBJECT TO ADDITIONAL RESTRICTIONS ON
 
                                      C-11
<PAGE>
    TRANSFER  AS SET  FORTH IN  THE OPTION  HOLDER STOCK  OPTION AND TRIGGER
    PAYMENT AGREEMENT, DATED AS OF NOVEMBER 10, 1995, A COPY OF WHICH MAY BE
    OBTAINED FROM THE ISSUER UPON REQUEST.
 
It is understood and agreed that:
 
        (i) the reference to the resale  restrictions of the Securities Act  and
    state  securities or Blue Sky  laws in the above  legend shall be removed by
    delivery of  substitute  certificate(s)  without such  reference  if  OPTION
    HOLDER  or OPTION GRANTOR, as  the case may be,  shall have delivered to the
    other party a copy of a letter from  the staff of the SEC, or an opinion  of
    counsel,  in  form and  substance satisfactory  to the  other party,  to the
    effect that such legend is not  required for purposes of the Securities  Act
    or such laws;
 
        (ii)  the reference  to the  provisions to  this Agreement  in the above
    legend shall be  removed by  delivery of  substitute certificate(s)  without
    such  reference if  the shares have  been sold or  transferred in compliance
    with the provisions of  this Agreement and under  circumstances that do  not
    require the retention of such reference; and
 
       (iii)  the legend shall be  removed in its entirety  if the conditions in
    the preceding clauses (i) and (ii) are both satisfied.
 
    In addition,  such  certificates shall  bear  any  other legend  as  may  be
    required  by  law. Certificates  representing  shares sold  in  a registered
    public offering pursuant  to Section 11  shall not be  required to bear  the
    legend set forth in this Section 13.
 
    14.  BINDING EFFECT; NO ASSIGNMENT; NO THIRD PARTY BENEFICIARIES.
 
        (a) This Agreement shall be binding upon and inure to the benefit of the
    parties hereto and their respective successors and permitted assigns.
 
        (b)  Except as  expressly provided for  in this  Agreement, neither this
    Agreement  nor  the  rights  or  obligations  of  either  party  hereto  are
    assignable,  except by operation of law, or  with the written consent of the
    other party.
 
        (c) Nothing contained in this Agreement, express or implied, is intended
    to confer upon any person other than the parties hereto and their respective
    successors and  permitted  assigns any  rights  or remedies  of  any  nature
    whatsoever by reason of this Agreement.
 
        (d)  Any  Restricted  Shares sold  by  a  party in  compliance  with the
    provisions of Section 11 shall, upon  consummation of such sale, be free  of
    the  restrictions imposed  with respect  to such  shares by  this Agreement,
    unless and  until  such  party  shall repurchase  or  otherwise  become  the
    beneficial owner of such shares, and any transferee of such shares shall not
    be entitled to the registration rights of such party.
 
    15.   SPECIFIC PERFORMANCE.  The  parties hereto agree that irreparable harm
would occur in the event that any  of the provisions of this Agreement were  not
performed  in accordance with their specified  terms or were otherwise breached.
It is  accordingly  agreed that  the  parties hereto  shall  be entitled  to  an
injunction  or injunctions to prevent breaches  of this Agreement and to enforce
specifically the terms and provisions hereof  in any court of the United  States
or  any state having jurisdiction, this being in addition to any other remedy to
which they are entitled at law or equity.
 
    16.  VALIDITY.
 
        (a)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement  shall  not affect  the validity  or  enforceability of  the other
    provisions of this Agreement, which shall remain in full force and effect.
 
        (b) In  the event  any  court or  other  competent authority  holds  any
    provisions  of this Agreement to be null, void or unenforceable, the parties
    hereto shall negotiate in good faith the
 
                                      C-12
<PAGE>
    execution and delivery of an amendment to this Agreement in order, as nearly
    as possible, to effectuate,  to the extent permitted  by law, the intent  of
    the  parties hereto with respect to  such provision and the economic effects
    thereof.
 
        (c) Subject to Section 5, if for any reason any such court or regulatory
    agency determines that OPTION HOLDER is not permitted to acquire, or  OPTION
    GRANTOR  is  not permitted  to repurchase  pursuant to  Section 8,  the full
    number of shares of OPTION GRANTOR Common Stock provided in Section 1 hereof
    (as the same may be adjusted), it is the express intention of OPTION GRANTOR
    to allow OPTION HOLDER to acquire or to require OPTION GRANTOR to repurchase
    such lesser number of shares as may be permissible without any amendment  or
    modification hereof.
 
        (d)  Each  party  agrees  that,  should  any  court  or  other competent
    authority hold any provision  of this Agreement or  part hereof to be  null,
    void  or unenforceable, or  order any party to  take any action inconsistent
    herewith, or not take any action required herein, the other party shall  not
    be  entitled to specific performance of such  provision or part hereof or to
    any other remedy,  including but not  limited to money  damages, for  breach
    hereof  or of any  other provision of  this Agreement or  part hereof as the
    result of such holding or order.
 
    17.  NOTICES.   All notices and other  communications hereunder shall be  in
writing and shall be deemed given if (a) delivered personally, or (b) if sent by
overnight courier service (receipt confirmed in writing), or (c) if delivered by
facsimile  transmission (with receipt  confirmed), or (d)  five days after being
mailed by registered or certified mail (return receipt requested) to the parties
in each case to the following addresses (or at such other address for a party as
shall be specified by like notice):
 
<TABLE>
<S>        <C>
A.         If to OPTION HOLDER, to:
           Interstate Power Company
           1000 Main Street
           Dubuque, Iowa 52004-0789
           Attention: Wayne H. Stoppelmoor
           Chairman
           Fax: (319) 557-2202
           with a copy to:
           Milbank, Tweed, Hadley & McCloy
           1 Chase Manhattan Plaza
           New York, New York 10005-1413
           Attention: John T. O'Connor, Esq.
           Fax: (212) 530-5219
B.         If to OPTION GRANTOR, to:
           WPL Holdings, Inc.
           222 West Washington Avenue
           Madison, Wisconsin 53703
           Attention: Erroll B. Davis, Jr.
           Fax: (608) 252-3137
           with a copy to:
           Foley & Lardner
           777 East Wisconsin Avenue
           Milwaukee, Wisconsin 53202-5367
           Attention: Benjamin F. Garmer, III, Esq.
           Fax: (414) 297-4900
</TABLE>
 
                                      C-13
<PAGE>
    18.  GOVERNING LAW.   This Agreement shall be  governed by and construed  in
accordance  with the laws of the State of Delaware applicable to agreements made
and to be performed entirely within such State and without regard to its  choice
of law principles or to any requirement as to jurisdiction or service of process
contained in Section 2708 of Title 6 of the Delaware Code.
 
    19.  INTERPRETATION.
 
        (a)  When reference is  made in this Agreement  to Articles, Sections or
    Exhibits, such reference shall be to an Article, Section or Exhibit of  this
    Agreement, as the case may be, unless otherwise indicated.
 
        (b)  The table of contents and  headings contained in this Agreement are
    for reference  purposes and  shall not  affect  in any  way the  meaning  or
    interpretation of the Agreement.
 
        (c) Whenever the words "include," "includes," or "including" are used in
    this  Agreement, they shall be  deemed to be followed  by the words "without
    limitation."
 
        (d) Whenever "or" is used in this Agreement it shall be construed in the
    nonexclusive sense.
 
    20.  COUNTERPARTS; EFFECT.   This Agreement may be  executed in one or  more
counterparts,  each of which shall be deemed to be an original, but all of which
shall constitute one and the same agreement.
 
    21.   AMENDMENTS; WAIVER.   This  Agreement may  be amended  by the  parties
hereto  and the terms and conditions hereof  may be waived only by an instrument
in writing signed on behalf of each of the parties hereto, or, in the case of  a
waiver, by an instrument signed on behalf of the party waiving compliance.
 
    22.   EXTENSION OF TIME PERIODS.   The time periods for exercises of certain
rights under Sections 2, 7 and 8 shall be extended (but in no event by more than
six months):
 
        (a) to the extent necessary to  obtain all regulatory approvals for  the
    exercise  of such  rights, and for  the expiration of  all statutory waiting
    periods; and
 
        (b) to the extent necessary to  avoid any liability under Section  16(b)
    of the Exchange Act by reason of such exercise.
 
    IN  WITNESS WHEREOF,  the parties  hereto have  caused this  Agreement to be
executed by their respective duly authorized officers as of the date first above
written.
 
                                          WPL HOLDINGS, INC.
 
                                          By: /s/ ERROLL B. DAVIS, JR.
 
                                          --------------------------------------
                                          Name: Erroll B. Davis, Jr.
                                          Title: President and Chief Executive
                                                 Officer
 
                                          INTERSTATE POWER COMPANY
 
                                          By: /s/ WAYNE H. STOPPELMOOR
 
                                          --------------------------------------
                                          Name: Wayne H. Stoppelmoor
                                          Title: Chairman of the Board,
                                                 President and Chief Executive
                                                 Officer
 
                                      C-14
<PAGE>
                                                                         ANNEX D
 
                   OPTION GRANTOR/OPTION HOLDER STOCK OPTION
                         AND TRIGGER PAYMENT AGREEMENT
 
    This STOCK OPTION AGREEMENT, dated as of November 10, 1995 (the "AGREEMENT")
by  and among IES Industries Inc., a corporation organized under the laws of the
State of Iowa  ("OPTION GRANTOR"  or the "COMPANY")  and WPL  Holdings, Inc.,  a
corporation  organized  under  the  laws  of  the  State  of  Wisconsin ("OPTION
HOLDER").
 
                         W I T N E S S E T H  T H A T:
 
    WHEREAS, concurrently with  the execution  and delivery  of this  Agreement,
OPTION GRANTOR, OPTION HOLDER, Interstate Power Company, a corporation organized
under  the laws of the State of Delaware ("INTERSTATE"), WPLH Acquisition Co., a
wholly-owned subsidiary of OPTION HOLDER organized  under the laws of the  State
of  Wisconsin  ("ACQUISITION"),  and Interstate  Power  Company,  a wholly-owned
subsidiary of Interstate organized under the laws of the State of Wisconsin, are
entering into an Agreement and Plan of Merger, dated as of November 10, 1995, as
amended (the "MERGER AGREEMENT"), which provides, INTER ALIA, upon the terms and
subject to the  conditions thereof, for  the merger of  OPTION GRANTOR with  and
into  OPTION HOLDER in accordance  with the laws of  the States of Wisconsin and
Iowa (the "IES MERGER"), and the merger of Acquisition with and into  Interstate
(or  a successor thereto) in accordance with  the laws of the States of Delaware
and/or Wisconsin (the "INTERSTATE MERGER", and together with the IES Merger, the
"MERGER");
 
    WHEREAS, in connection with  the execution of  the Merger Agreement,  OPTION
GRANTOR,  OPTION HOLDER  and Interstate are  entering into  certain stock option
agreements dated as of the date hereof, of which this Agreement is one,  whereby
the  parties hereto grant each other an option with respect to certain shares of
each other's common stock on the terms  and subject to the conditions set  forth
therein (the "STOCK OPTION AGREEMENTS"); and
 
    WHEREAS,  as a  condition to OPTION  HOLDER's willingness to  enter into the
Merger Agreement, OPTION  HOLDER has  requested that OPTION  GRANTOR agree,  and
OPTION  GRANTOR has so agreed, to grant  to OPTION HOLDER an option with respect
to certain shares of OPTION GRANTOR's common stock, on the terms and subject  to
the conditions set forth herein;
 
    NOW,  THEREFORE, to induce OPTION HOLDER  to enter into the Merger Agreement
and certain  of  the  Stock  Option Agreements,  and  in  consideration  of  the
representations,  warranties, covenants and agreements  contained herein, in the
Merger Agreement and in the Stock Option Agreements to which OPTION GRANTOR  and
OPTION  HOLDER are parties,  the parties hereto, intending  to be legally bound,
hereby agree as follows:
 
    1.  GRANT OF OPTION.
 
        (a) Subject  to  the receipt  of  all regulatory  approvals  and  orders
    required  by  OPTION GRANTOR  as  set forth  in  Section 5.4(c)  of  the IES
    Disclosure Schedule to  the Merger  Agreement and  by OPTION  HOLDER as  set
    forth  in  Section  4.4(c) of  the  WPL  Disclosure Schedule  to  the Merger
    Agreement, OPTION GRANTOR hereby grants OPTION HOLDER an irrevocable  option
    (the  "OPTION  GRANTOR OPTION")  to purchase  up to  that number  of shares,
    subject to  adjustment  as  provided  in Section  12  (the  "OPTION  GRANTOR
    SHARES"),  of common  stock, no  par value,  of OPTION  GRANTOR (the "OPTION
    GRANTOR  COMMON  STOCK")   equal  to  a   percentage  (the  "OPTION   SHARES
    PERCENTAGE"), which Option Shares Percentage is equal to the OPTION HOLDER's
    Participation  Percentage as defined  below in subsection  (e), of 5,861,115
    shares of OPTION GRANTOR Common Stock  (being 19.9% of the number of  shares
    of OPTION
 
                                      D-1
<PAGE>
    GRANTOR  Common Stock  issued and outstanding  as of November  10, 1995 (the
    "INITIAL NUMBER") in the manner set  forth below, at a price (the  "EXERCISE
    PRICE")  per OPTION GRANTOR  Share of $26.7125  (which is equal  to the Fair
    Market Value (as defined below)  of an OPTION GRANTOR  Share as of the  date
    hereof).
 
        (b)  The Exercise Price shall be  payable, at OPTION HOLDER's option, as
    follows:
 
           (i) in cash, or
 
           (ii) subject  to the  receipt of  all approvals  of any  Governmental
       Authority  required for OPTION  GRANTOR to acquire,  and OPTION HOLDER to
       issue, the OPTION HOLDER Shares (as defined below) from OPTION HOLDER, in
       shares of common stock, $.01 par value, of OPTION HOLDER ("OPTION  HOLDER
       SHARES"),
 
    in either case in accordance with Section 4 hereof.
 
        (c)  Notwithstanding  the foregoing,  in no  event  shall the  number of
    OPTION GRANTOR Shares  for which  the OPTION GRANTOR  Option is  exercisable
    exceed  the product of the Option  Shares Percentage and the Initial Number,
    subject to adjustment as provided in Section 12.
 
        (d) As used herein, the  "FAIR MARKET VALUE" of  any share shall be  the
    average  of the  daily closing sales  price for  such share on  the New York
    Stock Exchange (the "NYSE")  during the ten NYSE  trading days prior to  the
    fifth  NYSE trading day preceding  the date such Fair  Market Value is to be
    determined.
 
        (e) For purposes of this  Agreement the term "PARTICIPATION  PERCENTAGE"
    shall  have  the  same  meaning  as  in  Section  10.3(f)(i)  of  the Merger
    Agreement, except that  the numerator  and denominator  shall be  calculated
    based  on the number of  shares of WPL Common  Stock which would be issuable
    (or, in the case of  WPL, retained by its  shareholders) on a fully  diluted
    basis  had the Effective Time occurred as  of the date on which the Exercise
    Notice is delivered under Section 2 hereof  or the date on which demand  for
    the  Trigger Payment (as defined herein) is given under Section 5 hereof, as
    the case may be. Other capitalized terms used herein but not defined  herein
    shall have the meanings set forth in the Merger Agreement.
 
    2.  EXERCISE OF OPTION.
 
        (a)  The OPTION  GRANTOR Option  may be  exercised by  OPTION HOLDER, in
    whole or  in part,  at  any time  or  from time  to  time after  the  Merger
    Agreement  becomes  terminable by  OPTION  HOLDER under  circumstances which
    could entitle OPTION HOLDER  to a termination fee  under Section 10.3(a)  of
    the  Merger  Agreement  (provided  that  the  events  specified  in  Section
    10.3(a)(ii)(A) of the  Merger Agreement  shall have  occurred, although  the
    events  specified in Section 10.3(a)(ii)(B) thereof need not have occurred),
    or Section 10.3(b) of the Merger Agreement (regardless of whether the Merger
    Agreement is actually terminated  or whether there occurs  a closing of  any
    Business Combination involving a Target Party or a closing by which a Target
    Party  becomes a Subsidiary),  any such event by  which the Merger Agreement
    becomes so  terminable  by OPTION  HOLDER  being  referred to  herein  as  a
    "TRIGGER EVENT").
 
         (b)(i) OPTION GRANTOR shall notify OPTION HOLDER promptly in writing of
       the  occurrence of any Trigger Event, it being understood that the giving
       of such notice by OPTION GRANTOR shall not be a condition to the right of
       OPTION HOLDER to exercise the OPTION GRANTOR Option.
 
           (ii) In the event OPTION HOLDER wishes to exercise the OPTION GRANTOR
       Option, OPTION HOLDER shall deliver to OPTION GRANTOR written notice  (an
       "EXERCISE  NOTICE") specifying the total  number of OPTION GRANTOR Shares
       it wishes to purchase.
 
          (iii) Upon  the giving  by  OPTION HOLDER  to  OPTION GRANTOR  of  the
       Exercise  Notice  and the  tender  of the  applicable  aggregate Exercise
       Price, OPTION HOLDER, to the extent permitted by law and OPTION GRANTOR's
       organizational documents, and provided
 
                                      D-2
<PAGE>
       that the conditions to  OPTION GRANTOR's obligation  to issue the  OPTION
       GRANTOR  Shares to  OPTION HOLDER hereunder  set forth in  Section 3 have
       been satisfied or waived, shall be deemed  to be the holder of record  of
       the  OPTION GRANTOR  Shares issuable upon  such exercise, notwithstanding
       that the stock transfer books of  OPTION GRANTOR shall then be closed  or
       that  certificates representing such OPTION GRANTOR Shares shall not then
       be actually delivered to OPTION HOLDER.
 
          (iv) Each closing of a purchase of OPTION GRANTOR Shares (a "CLOSING")
       shall occur at a  place, on a  date, and at a  time designated by  OPTION
       HOLDER  in an Exercise Notice delivered  at least two business days prior
       to the date of the Closing.
 
        (c) The OPTION GRANTOR Option shall terminate upon the earliest to occur
    of:
 
           (i) the Effective Time of the Merger;
 
           (ii) the termination of the Merger Agreement pursuant to Section 10.1
       thereof, other than under circumstances  which also constitute a  Trigger
       Event under this Agreement;
 
          (iii)  180 days following any termination of the Merger Agreement upon
       or during the continuance of a Trigger Event (or if, at the expiration of
       such 180 day  period, the OPTION  GRANTOR Option cannot  be exercised  by
       reason  of any applicable judgment, decree, order, law or regulation, ten
       business days after such impediment  to exercise shall have been  removed
       or  shall have become  final and not  subject to appeal,  but in no event
       under this clause (iii) later than May 10, 1998); and
 
          (iv) payment by  OPTION GRANTOR of  the Trigger Payment  set forth  in
       Section 5 of this Agreement to OPTION HOLDER.
 
        (d)  Notwithstanding the foregoing, the OPTION GRANTOR Option may not be
    exercised if  (i)  OPTION  HOLDER  is  in material  breach  of  any  of  its
    representations or warranties, or in material breach of any of its covenants
    or  agreements, contained in  this Agreement or in  the Merger Agreement, or
    (ii) a Trigger Payment has been paid pursuant to Section 5 of this Agreement
    or demand therefor has been made and not withdrawn.
 
    3.  CONDITIONS TO CLOSING.   The obligation of  OPTION GRANTOR to issue  the
OPTION  GRANTOR Shares to  OPTION HOLDER hereunder is  subject to the conditions
that
 
        (a) all waiting  periods, if any,  under the HSR  Act applicable to  the
    issuance  and acquisition of the OPTION  GRANTOR Shares hereunder shall have
    expired or have been terminated;
 
        (b) the OPTION GRANTOR  Shares, and any OPTION  HOLDER Shares which  are
    issued  in  payment of  the  Exercise Price,  shall  have been  approved for
    listing on the NYSE subject only to official notice of issuance;
 
        (c)  all   consents,  approvals,   orders  or   authorizations  of,   or
    registrations,  declarations or  filings with,  any federal,  state or local
    administrative agency  or  commission  or  other  federal,  state  or  local
    Governmental  Authority, if any, required in connection with the issuance by
    OPTION GRANTOR and the  acquisition by OPTION HOLDER  of the OPTION  GRANTOR
    Shares  hereunder  shall  have  been obtained  or  made,  including, without
    limitation, the approval of the  SEC under Sections 9  and 10 of the  Public
    Utility  Holding  Company Act  of  1935, as  amended  (the "1935  ACT"), the
    approval of the Iowa Utilities Board  of the issuance of the OPTION  GRANTOR
    Shares  by  OPTION GRANTOR  and, if  applicable,  the acquisition  of OPTION
    GRANTOR Shares by  OPTION HOLDER,  and the  approval of  the Public  Service
    Commission  of Wisconsin of the acquisition  of the OPTION GRANTOR Shares by
    OPTION HOLDER and, if applicable, the  acquisition by OPTION GRANTOR of  the
    OPTION HOLDER Shares constituting the Exercise Price hereunder; and
 
                                      D-3
<PAGE>
        (d)  no preliminary or permanent injunction  or other order by any court
    of competent jurisdiction prohibiting or otherwise restraining such issuance
    shall be in effect.
 
The condition set forth in paragraph (b) above may be waived by OPTION  GRANTOR,
in the case of OPTION HOLDER Shares, and by OPTION HOLDER, in the case of OPTION
GRANTOR Shares, in the sole discretion of the waiving party.
 
    4.  CLOSING.  At any Closing,
 
        (a)  OPTION GRANTOR  shall deliver  to OPTION  HOLDER or  its designee a
    single certificate  in definitive  form representing  the number  of  OPTION
    GRANTOR  Shares designated  by OPTION  HOLDER in  its Exercise  Notice, such
    certificate to be registered in  the name of OPTION  HOLDER and to bear  the
    legend set forth in Section 13; and
 
        (b)  OPTION HOLDER shall  deliver to OPTION  GRANTOR the aggregate price
    for the OPTION GRANTOR Shares so designated and being purchased by
 
           (i) wire transfer of immediately  available funds or certified  check
       or bank check, or
 
           (ii)  subject to  the condition  in Section  1(b)(ii), delivery  of a
       certificate or  certificates representing  the  number of  OPTION  HOLDER
       Shares being issued by OPTION HOLDER in consideration thereof, determined
       in accordance with Section 4(c).
 
        (c)  In  the event  that OPTION  HOLDER issues  OPTION HOLDER  Shares to
    OPTION GRANTOR in consideration of OPTION GRANTOR Shares pursuant to Section
    4(b)(ii), the number of OPTION HOLDER Shares to be so issued shall be  equal
    to the quotient obtained by dividing:
 
           (i)  the  product of  (x) the  number of  OPTION GRANTOR  Shares with
       respect to which the OPTION GRANTOR Option is being exercised and (y) the
       Exercise Price, by
 
           (ii) the Fair Market Value of the OPTION HOLDER Shares as of the date
       immediately preceding the date the Exercise Notice is delivered to OPTION
       GRANTOR.
 
        (d) OPTION GRANTOR  shall pay  all expenses,  and any  and all  Federal,
    state  and local taxes and  other charges that may  be payable in connection
    with the preparation, issue  and delivery of  stock certificates under  this
    Section 4.
 
    5.  TRIGGER PAYMENT.
 
        (a)   TRIGGER PAYMENT.  Subject to  the provisions of Section 10.3(e) of
    the Merger  Agreement,  if a  Trigger  Event  shall have  occurred  and  any
    regulatory approval or order required for the issuance by OPTION GRANTOR, or
    the  acquisition by OPTION HOLDER, of  the OPTION GRANTOR Option pursuant to
    Section 1 hereof shall not have been obtained, OPTION HOLDER shall have  the
    right  to receive, and OPTION GRANTOR shall  pay to OPTION HOLDER, an amount
    (the "TRIGGER PAYMENT") equal to the product of
 
           (i) the maximum number of OPTION GRANTOR Shares that would have  been
       subject  to purchase by OPTION HOLDER upon exercise of the OPTION GRANTOR
       Option pursuant  to  Sections 1  and  2  hereof if  all  such  regulatory
       approvals or orders had been obtained, and
 
           (ii)  the difference between  (A) the Market/Offer  Price (as defined
       herein), determined as  of the  date on which  notice of  demand for  the
       Trigger  Payment is  given by OPTION  HOLDER, and (B)  the Exercise Price
       (but only if such Market/Offer Price is higher than such Exercise Price).
 
    Demand for the Trigger Payment shall  be given by notice in accordance  with
    the  provisions of Section 17  hereof. The Trigger Payment  shall be paid to
    OPTION HOLDER by OPTION
 
                                      D-4
<PAGE>
    GRANTOR on  the  Payment Date  (as  defined  herein), by  wire  transfer  of
    immediately  available funds  to an account  to be designated  in writing by
    OPTION HOLDER not less than two business days before the Payment Date.
 
        (b)  PAYMENT DATE.  For purposes of this Section 5, "PAYMENT DATE" means
    the date on which termination fees are required to be paid by OPTION GRANTOR
    to OPTION HOLDER under Section  10.3(a) or 10.3(b), as  the case may be,  of
    the  Merger Agreement  as a  result of the  occurrence of  the Trigger Event
    referred to in subsection (a) of this Section 5.
 
        (c)  CERTAIN CONDITIONS.  OPTION GRANTOR shall have no obligation to pay
    the Trigger Payment if  OPTION HOLDER is  in material breach  of any of  its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in this Agreement or in the Merger Agreement.
 
    6.    REPRESENTATIONS  AND WARRANTIES  OF  OPTION GRANTOR.    OPTION GRANTOR
represents and warrants to OPTION HOLDER that
 
        (a) except as set forth in Section 5.4(a) of the IES Disclosure Schedule
    to the  Merger  Agreement,  OPTION  GRANTOR  has  the  corporate  power  and
    authority  to enter  into this  Agreement and  to carry  out its obligations
    hereunder, subject  in the  case of  the repurchase  of the  OPTION  GRANTOR
    Shares  pursuant to  Section 8(a)  to applicable  law and  the provisions of
    OPTION GRANTOR's Articles of Incorporation, as amended (the "OPTION  GRANTOR
    ARTICLES");
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION GRANTOR, and, assuming the due authorization, execution and  delivery
    hereof  by  OPTION  HOLDER  and  the  receipt  of  all  required  regulatory
    approvals, constitutes a  valid and  binding obligation  of OPTION  GRANTOR,
    enforceable  against OPTION GRANTOR in accordance  with its terms, except as
    may be limited by applicable bankruptcy, insolvency, reorganization or other
    similar laws affecting the enforcement  of creditors' rights generally,  and
    except  that  the  availability of  equitable  remedies,  including specific
    performance, may be subject to the discretion of any court before which  any
    proceeding therefor may be brought;
 
        (c) OPTION GRANTOR has taken all necessary corporate action to authorize
    and  reserve for issuance  and to permit  it to issue,  upon exercise of the
    OPTION GRANTOR Option,  and at all  times from the  date hereof through  the
    expiration  of the  OPTION GRANTOR  Option will  have reserved,  the Initial
    Number of authorized and unissued  OPTION GRANTOR Shares, such amount  being
    subject  to adjustment as provided  in Section 12, all  of which, upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d) upon delivery of the OPTION GRANTOR Shares to OPTION HOLDER upon the
    exercise of the OPTION GRANTOR Option, OPTION HOLDER will acquire the OPTION
    GRANTOR  Shares free and  clear of all  claims, liens, charges, encumbrances
    and security interests of any nature whatsoever;
 
        (e) except as described in Section 5.4(b) of the IES Disclosure Schedule
    to the Merger  Agreement, the execution  and delivery of  this Agreement  by
    OPTION  GRANTOR does not, and, subject to compliance with applicable law and
    the OPTION GRANTOR  Articles with respect  to the repurchase  of the  OPTION
    GRANTOR  Shares pursuant to Section 8(a), the consummation by OPTION GRANTOR
    of the transactions contemplated hereby will not violate, conflict with,  or
    result  in a breach  of any provision  of, or constitute  a default (with or
    without notice  or  a lapse  of  time, or  both)  under, or  result  in  the
    termination  of, or accelerate  the performance required by,  or result in a
    right of termination, cancellation, or acceleration of any obligation or the
    loss of  a  material benefit  under,  or the  creation  of a  lien,  pledge,
    security interest or other encumbrance on
 
                                      D-5
<PAGE>
    assets  (any  such  conflict,  violation,  default,  right  of  termination,
    cancellation, acceleration, loss or creation, hereinafter a "VIOLATION")  of
    OPTION GRANTOR or any of its Subsidiaries, pursuant to
 
           (i)  any provision  of the OPTION  GRANTOR Articles or  the Bylaws of
       OPTION GRANTOR,
 
           (ii) any provisions of any  material loan or credit agreement,  note,
       mortgage,  indenture, lease, benefit plan or other agreement, obligation,
       instrument,  permit,  concession,  franchise  or  license  (any  of   the
       foregoing  in effect on the date hereof  being referred to as a "MATERIAL
       CONTRACT") of OPTION GRANTOR or its subsidiaries or to which any of  them
       is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable to OPTION GRANTOR or its properties or assets,
 
    which Violation,  in  the  case  of  each  clauses  (ii)  and  (iii),  could
    reasonably  be expected  to have an  OPTION GRANTOR  Material Adverse Effect
    (except that no representation or warranty is given concerning any Violation
    of a Material  Contract with  respect to  the repurchase  of OPTION  GRANTOR
    Shares pursuant to Section 8(a));
 
        (f) except as described in Section 5.4(c) of the IES Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of  this Agreement by OPTION  GRANTOR does not, and  the performance of this
    Agreement by  OPTION  GRANTOR  will  not,  require  any  consent,  approval,
    authorization or permit of, filing with or notification to, any Governmental
    Authority;
 
        (g)  none of OPTION GRANTOR,  any of its affiliates  or anyone acting on
    its or their  behalf, has  issued, sold or  offered any  security of  OPTION
    GRANTOR  to any person under circumstances that would cause the issuance and
    sale of OPTION  GRANTOR Shares,  as contemplated  by this  Agreement, to  be
    subject  to the registration requirements of the Securities Act as in effect
    on the  date hereof,  and, assuming  the representations  and warranties  of
    OPTION  HOLDER contained in Section 7(g) are true and correct, the issuance,
    sale and delivery  of the OPTION  GRANTOR Shares hereunder  would be  exempt
    from the registration and prospectus delivery requirements of the Securities
    Act,  as in effect on the date hereof (and OPTION GRANTOR shall not take any
    action which would cause the issuance, sale, and delivery of OPTION  GRANTOR
    Shares hereunder not to be exempt from such requirements); and
 
        (h) any OPTION HOLDER Shares acquired pursuant to this Agreement will be
    acquired for OPTION GRANTOR's own account, for investment purposes only, and
    will  not  be  acquired  by  OPTION  GRANTOR  with  a  view  to  the  public
    distribution thereof  in  violation  of  any  applicable  provision  of  the
    Securities Act.
 
    7.    REPRESENTATIONS  AND  WARRANTIES  OF  OPTION  HOLDER.    OPTION HOLDER
represents and warrants to OPTION GRANTOR that
 
        (a) except  as  set forth  in  Schedule  4.4(a) of  the  WPL  Disclosure
    Schedule  to the Merger Agreement, OPTION HOLDER has the corporate power and
    authority to enter  into this  Agreement and  to carry  out its  obligations
    hereunder;
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION HOLDER and,  assuming the due  authorization, execution and  delivery
    hereof  by  OPTION  GRANTOR  and  the  receipt  of  all  required regulatory
    approvals, constitutes  a valid  and binding  obligation of  OPTION  HOLDER,
    enforceable  against OPTION HOLDER in  accordance with its respective terms,
    except  as   may   be   limited  by   applicable   bankruptcy,   insolvency,
    reorganization,   or  other  similar  laws   affecting  the  enforcement  of
    creditors' rights generally, and except  that the availability of  equitable
    remedies,  including specific performance, may  be subject to the discretion
    of any court before which any proceeding may be brought;
 
                                      D-6
<PAGE>
        (c) prior to any  delivery of OPTION HOLDER  Shares in consideration  of
    the  purchase of OPTION  GRANTOR Shares pursuant  hereto, OPTION HOLDER will
    have taken all necessary corporate action  to authorize for issuance and  to
    permit  it to  issue such  OPTION HOLDER  Shares, all  of which,  upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be  duly authorized, validly issued, fully paid and nonassessable (except as
    otherwise provided in Section 180.0622(2)(b) of the WBCL);
 
        (d) upon any delivery of such OPTION HOLDER Shares to OPTION GRANTOR  in
    consideration  of  the purchase  of OPTION  GRANTOR Shares  pursuant hereto,
    OPTION GRANTOR will acquire the OPTION  HOLDER Shares free and clear of  all
    claims,  liens, charges, encumbrances  and security interests  of any nature
    whatsoever;
 
        (e) except as described in Section 4.4(b) of the WPL Disclosure Schedule
    to the Merger  Agreement, the execution  and delivery of  this Agreement  by
    OPTION  HOLDER  does  not, and  the  consummation  by OPTION  HOLDER  of the
    transactions contemplated hereby will not, violate, conflict with, or result
    in the breach of any provision of, or constitute a default (with or  without
    notice  or a lapse  of time, or both)  under, or result  in any Violation by
    OPTION HOLDER or any of its Subsidiaries, pursuant to
 
           (i) any  provision of  the  Articles of  Incorporation or  Bylaws  of
       OPTION HOLDER,
 
           (ii)   any  Material  Contract  of  OPTION   HOLDER  or  any  of  its
       subsidiaries or to which any of them is a party, or
 
          (iii) any judgment,  order, decree, statute,  law, ordinance, rule  or
       regulation applicable to OPTION HOLDER or its properties or assets,
 
    which Violation, in the case of each of clauses (ii) or (iii), would have an
    OPTION HOLDER Material Adverse Effect;
 
        (f) except as described in Section 4.4(c) of the WPL Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of  this Agreement by OPTION HOLDER does not, and the consummation by OPTION
    HOLDER of  the  transactions  contemplated  hereby  will  not,  require  any
    consent,  approval, authorization or permit  of, filing with or notification
    to, any Governmental Authority; and
 
        (g) any  OPTION GRANTOR  Shares  acquired upon  exercise of  the  OPTION
    GRANTOR  Option  will  be  acquired for  OPTION  HOLDER's  own  account, for
    investment purposes only and will not  be, and the OPTION GRANTOR Option  is
    not  being, acquired by OPTION HOLDER with a view to the public distribution
    thereof, in violation of any applicable provision of the Securities Act.
 
    8.  CERTAIN REPURCHASES.
 
        (a)  OPTION HOLDER "PUT".   At the request  of OPTION HOLDER by  written
    notice (x) at any time during which the OPTION GRANTOR Option is exercisable
    pursuant  to Section  2 (the  "REPURCHASE PERIOD"),  OPTION GRANTOR  (or any
    successor entity thereof) shall, if permitted by applicable law, the  OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase from  OPTION HOLDER  all or  any portion  of the  OPTION  GRANTOR
    Option,  at the price  set forth in  subparagraph (i) below,  or, (y) at any
    time prior to May 10, 1997 (provided that such date shall be extended to May
    10, 1998 under the circumstances where the date after which either party may
    terminate the Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger
    Agreement  has  been  extended to  May  10,  1998), OPTION  GRANTOR  (or any
    successor entity thereof) shall, if permitted by applicable law, the  OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase from  OPTION HOLDER  all or  any portion  of the  OPTION  GRANTOR
    Shares  purchased by OPTION HOLDER pursuant to the OPTION GRANTOR Option, at
    the price set forth in subparagraph (ii) below:
 
                                      D-7
<PAGE>
         (i)(A) The  difference between  the  "Market/Offer Price"  (as  defined
       below)  for shares of OPTION  GRANTOR Common Stock as  of the date OPTION
       HOLDER gives  notice of  its intent  to exercise  its rights  under  this
       Section  8 and  the Exercise  Price, multiplied  by the  number of OPTION
       GRANTOR Shares  purchasable pursuant  to the  OPTION GRANTOR  Option  (or
       portion  thereof with  respect to which  OPTION HOLDER  is exercising its
       rights under  this Section  8), but  only if  the Market/Offer  Price  is
       greater than the Exercise Price.
 
           (B)  For purposes of this Agreement, "Market/Offer Price" shall mean,
       as of any date, the higher of (I) the price per share offered as of  such
       date pursuant to any tender or exchange offer or other offer with respect
       to  a Business Combination  involving OPTION GRANTOR  as the Target Party
       which was made prior to such date  and not terminated or withdrawn as  of
       such  date and (II) the Fair Market  Value of OPTION GRANTOR Common Stock
       as of such date.
 
        (ii)(A) The product of  (I) the sum  of (a) the  Exercise Price paid  by
       OPTION  HOLDER per OPTION  GRANTOR Share acquired  pursuant to the OPTION
       GRANTOR Option,  and (b)  the difference  between the  "Offer Price"  (as
       defined  below) and the  Exercise Price, but  only if the  Offer Price is
       greater than the Exercise  Price, and (II) the  number of OPTION  GRANTOR
       Shares so to be repurchased pursuant to this Section 8.
 
           (B)  For purposes of this clause (ii), the "Offer Price" shall be the
       highest price per share offered pursuant to a tender or exchange offer or
       other Business Combination offer involving  OPTION GRANTOR as the  Target
       Party during the Repurchase Period prior to the delivery by OPTION HOLDER
       of a notice of repurchase.
 
        (b)   REDELIVERY OF OPTION  HOLDER SHARES.  If  OPTION HOLDER shall have
    previously elected  to  purchase  OPTION  GRANTOR  Shares  pursuant  to  the
    exercise of the OPTION GRANTOR Option by the issuance and delivery of OPTION
    HOLDER  Shares, then OPTION GRANTOR shall, if so requested by OPTION HOLDER,
    in fulfillment of its obligation pursuant to Section 8(a)(y) (that is,  with
    respect  to the Exercise Price only and without limitation to its obligation
    to pay additional consideration under clause (b) of Section 8(a)(ii)(A)(I)),
    redeliver the certificates for such  OPTION HOLDER Shares to OPTION  HOLDER,
    free and clear of all liens, claims, charges and encumbrances of any kind or
    nature  whatsoever; PROVIDED, HOWEVER, that if at  any time less than all of
    the OPTION GRANTOR  Shares so  purchased by  OPTION HOLDER  pursuant to  the
    OPTION  GRANTOR Option are  to be repurchased by  OPTION GRANTOR pursuant to
    Section 8(a)(y), then (i) OPTION GRANTOR shall be obligated to redeliver  to
    OPTION HOLDER the same proportion of such OPTION HOLDER Shares as the number
    of OPTION GRANTOR Shares that OPTION GRANTOR is then obligated to repurchase
    bears  to the number of OPTION GRANTOR Shares acquired by OPTION HOLDER upon
    exercise of the OPTION GRANTOR Option and (ii) OPTION HOLDER shall issue  to
    OPTION  GRANTOR  new certificates  representing  those OPTION  HOLDER Shares
    which are  not due  to be  redelivered  to OPTION  HOLDER pursuant  to  this
    Section  8(b) to the extent that excess OPTION HOLDER Shares are included in
    the certificates redelivered to OPTION HOLDER by OPTION GRANTOR.
 
        (c)  PAYMENT AND REDELIVERY OF OPTION GRANTOR OPTIONS OR SHARES. In  the
    event  OPTION  HOLDER  exercises its  rights  under this  Section  8, OPTION
    GRANTOR shall, within ten business days thereafter, pay the required  amount
    to  OPTION HOLDER  in immediately  available funds  and OPTION  HOLDER shall
    surrender to OPTION GRANTOR the OPTION GRANTOR Option or the certificate  or
    certificates evidencing the OPTION GRANTOR Shares purchased by OPTION HOLDER
    pursuant  hereto, and  OPTION HOLDER shall  warrant that it  owns the OPTION
    GRANTOR Option or  such shares and  that the OPTION  GRANTOR Option or  such
    shares  are then free and  clear of all liens,  claims, damages, charges and
    encumbrances of any kind or nature whatsoever.
 
                                      D-8
<PAGE>
        (d)  OPTION  HOLDER "CALL".   If OPTION HOLDER  has elected to  purchase
    OPTION  GRANTOR Shares pursuant to the exercise of the OPTION GRANTOR Option
    by the issuance and delivery  of OPTION HOLDER Shares, notwithstanding  that
    OPTION  HOLDER may  no longer  hold any such  OPTION GRANTOR  Shares or that
    OPTION HOLDER elects not to exercise its other rights under this Section  8,
    OPTION HOLDER may require, at any time or from time to time prior to May 10,
    1997  (provided that such date  shall be extended to  May 10, 1998 under the
    circumstances where  the date  after which  either party  may terminate  the
    Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger Agreement has
    been extended to May 10, 1998), OPTION GRANTOR to sell to OPTION HOLDER  any
    such  OPTION HOLDER  Shares at  the price  attributed to  such OPTION HOLDER
    Shares pursuant to Section 4 plus interest at the rate of 8.75% per annum on
    such amount from the  Closing Date relating to  the exchange of such  OPTION
    HOLDER  Shares pursuant to Section 4 to  the Closing Date under this Section
    8(d) less any dividends on such OPTION HOLDER Shares paid during such period
    or declared and  payable to  stockholders of record  on a  date during  such
    period.
 
        (e)   REPURCHASE PRICE REDUCED AT OPTION  HOLDER'S OPTION.  In the event
    the repurchase price specified in Section 8(a) would subject the purchase of
    the OPTION GRANTOR Option or the  OPTION GRANTOR Shares purchased by  OPTION
    HOLDER  pursuant to the OPTION GRANTOR Option  to a vote of the shareholders
    of OPTION GRANTOR pursuant to applicable law or the OPTION GRANTOR Articles,
    then OPTION HOLDER may, at its  election, reduce the repurchase price to  an
    amount  which would permit such repurchase  without the necessity for such a
    shareholder vote.
 
    9.  VOTING  OF SHARES.   Following the date  hereof and prior  to the  fifth
anniversary  of the date  hereof (the "EXPIRATION DATE"),  each party shall vote
any shares of capital stock of the  other party acquired by such party  pursuant
to  this  Agreement ("RESTRICTED  SHARES"), including  any OPTION  HOLDER Shares
issued pursuant to  Section 1(b),  or otherwise beneficially  owned (within  the
meaning  of Rule 13d-3 promulgated under the Securities Exchange Act of 1934, as
amended (the "EXCHANGE ACT")), by such party on each matter submitted to a  vote
of  shareholders of  such other party  for and  against such matter  in the same
proportion as the vote of all other  shareholders of such other party are  voted
(whether by proxy or otherwise) for and against such matter.
 
    10.  RESTRICTIONS ON TRANSFER.
 
        (a)   RESTRICTIONS ON  TRANSFER.  Prior to  the Expiration Date, neither
    party shall, directly or indirectly, by operation of law or otherwise, sell,
    assign, pledge, or otherwise  dispose of or  transfer any Restricted  Shares
    beneficially  owned by such party, other than  (i) pursuant to Section 8, or
    (ii) in accordance with Section 10(b) or Section 11.
 
        (b)   PERMITTED  SALES.     Following  the  termination  of  the  Merger
    Agreement,  a  party  shall  be  permitted  to  sell  any  Restricted Shares
    beneficially owned  by it  if such  sale is  made pursuant  to a  tender  or
    exchange   offer  that  has  been  approved  or  recommended,  or  otherwise
    determined to be fair to  and in the best  interests of the shareholders  of
    the  other party, by a majority of the  members of the Board of Directors of
    such other party, which majority shall  include a majority of directors  who
    were directors prior to the announcement of such tender or exchange offer.
 
    11.  REGISTRATION RIGHTS.
 
        (a)  Following  the termination  of the  Merger Agreement,  either party
    hereto that owns Restricted  Shares (a "DESIGNATED  HOLDER") may by  written
    notice  (the "Registration  Notice") to  the other  party (the "REGISTRANT")
    request the Registrant to register under the Securities Act all or any  part
    of  the Restricted Shares beneficially owned  by such Designated Holder (the
    "REGISTRABLE  SECURITIES")  pursuant   to  a  bona   fide  firm   commitment
    underwritten  public  offering,  in  which  the  Designated  Holder  and the
    underwriters shall  effect  as  wide  a  distribution  of  such  Registrable
    Securities  as is reasonably practicable and shall use their best efforts to
    prevent any person
 
                                      D-9
<PAGE>
    (including any Group (as used in Rule 13d-5 under the Exchange Act)) and its
    affiliates  from  purchasing   through  such   offering  Restricted   Shares
    representing  more than 1% of the outstanding  shares of common stock of the
    Registrant on a fully diluted basis (a "PERMITTED OFFERING").
 
        (b) The Registration Notice shall include a certificate executed by  the
    Designated  Holder and its proposed  managing underwriter, which underwriter
    shall be an investment banking  firm of nationally recognized standing  (the
    "MANAGER"), stating that
 
           (i) they have a good faith intention to commence promptly a Permitted
       Offering, and
 
           (ii)   the  manager  in  good  faith  believes  that,  based  on  the
       then-prevailing  market  conditions,  it  will   be  able  to  sell   the
       Registrable  Securities at a per share price equal to at least 80% of the
       then Fair Market Value of such shares.
 
        (c) The  Registrant (and/or  any person  designated by  the  Registrant)
    shall  thereupon have the option exercisable  by written notice delivered to
    the Designated Holder  within ten  business days  after the  receipt of  the
    Registration Notice, irrevocably to agree to purchase all or any part of the
    Registrable  Securities proposed  to be  so sold  for cash  at a  price (the
    "OPTION PRICE")  equal to  the  product of  (i)  the number  of  Registrable
    Securities  to be  so purchased  by the  Registrant and  (ii) the  then Fair
    Market Value of such shares.
 
        (d) Any purchase  of Registrable  Securities by the  Registrant (or  its
    designee)  under Section 11(c) shall  take place at a  closing to be held at
    the principal executive offices of the  Registrant or at the offices of  its
    counsel  at any reasonable date and time designated by the Registrant and/or
    such designee in such notice within  twenty business days after delivery  of
    such notice, and any payment for the shares to be so purchased shall be made
    by delivery at the time of such closing in immediately available funds.
 
        (e)  If the Registrant does not elect to exercise its option pursuant to
    this Section 11 with respect to all Registrable Securities, it shall use its
    best efforts to effect, as  promptly as practicable, the registration  under
    the  Securities Act of the unpurchased Registrable Securities proposed to be
    so sold; PROVIDED, HOWEVER, that
 
           (i) neither party shall be entitled to demand more than an  aggregate
       of two effective registration statements hereunder, and
 
           (ii)   the  Registrant  will  not  be   required  to  file  any  such
       registration statement during any period of  time (not to exceed 40  days
       after such request in the case of clause (A) below or 90 days in the case
       of clauses (B) and (C) below) when
 
               (A)  the  Registrant  is  in  possession  of  material non-public
           information which it reasonably believes  would be detrimental to  be
           disclosed  at  such  time  and,  in the  opinion  of  counsel  to the
           Registrant, such information would be  required to be disclosed if  a
           registration statement were filed at that time;
 
               (B)  the  Registrant  is  required under  the  Securities  Act to
           include  audited  financial  statements   for  any  period  in   such
           registration  statement  and such  financial  statements are  not yet
           available for inclusion in such registration statement; or
 
               (C) the Registrant determines,  in its reasonable judgment,  that
           such  registration would interfere with any financing, acquisition or
           other material transaction  involving the  Registrant or  any of  its
           affiliates.
 
        (f)  The Registrant shall  use its reasonable best  efforts to cause any
    Registrable  Securities  registered  pursuant  to  this  Section  11  to  be
    qualified   for  sale  under  the  securities  or  Blue  Sky  laws  of  such
    jurisdictions as  the Designated  Holder may  reasonably request  and  shall
    continue  such registration or qualification in effect in such jurisdiction;
    PROVIDED, HOWEVER, that the Registrant shall  not be required to qualify  to
    do   business  in,  or  consent  to  general  service  of  process  in,  any
    jurisdiction by reason of this provision.
 
                                      D-10
<PAGE>
        (g) The registration rights set forth in this Section 11 are subject  to
    the  condition that the Designated Holder  shall provide the Registrant with
    such information with respect to  such holder's Registrable Securities,  the
    plans  for the distribution thereof, and such other information with respect
    to such holder as, in the reasonable judgment of counsel for the Registrant,
    is necessary  to  enable the  Registrant  to include  in  such  registration
    statement  all material  facts required  to be  disclosed with  respect to a
    registration thereunder.
 
        (h) A registration effected under this  Section 11 shall be effected  at
    the  Registrant's expense, except for underwriting discounts and commissions
    and the fees and the expenses of  counsel to the Designated Holder, and  the
    Registrant  shall provide to the  underwriters such documentation (including
    certificates, opinions of counsel and "comfort" letters from auditors) as is
    customary  in  connection  with   underwritten  public  offerings  as   such
    underwriters may reasonably require.
 
        (i)  In connection with any registration effected under this Section 11,
    the parties agree
 
           (i) to indemnify  each other  and the underwriters  in the  customary
       manner,
 
           (ii)  to enter into  an underwriting agreement  in form and substance
       customary for transactions of  such type with the  Manager and the  other
       underwriters participating in such offering, and
 
          (iii)  to take all further actions which shall be reasonably necessary
       to effect such registration and sale  (including if the Manager deems  it
       necessary, participating in road-show presentations).
 
        (j)    The Registrant  shall  be entitled  to  include (at  its expense)
    additional shares of its common stock in a registration effected pursuant to
    this Section 11 only if and to  the extent the Manager determines that  such
    inclusion  will  not  adversely affect  the  prospects for  success  of such
    offering.
 
    12.  ADJUSTMENT UPON CHANGES IN  CAPITALIZATION.  Without limitation to  any
restriction  on  OPTION GRANTOR  contained in  this Agreement  or in  the Merger
Agreement, in the event of any change  in OPTION GRANTOR Common Stock by  reason
of    stock   dividends,   splitups,   mergers    (other   than   the   Merger),
recapitalizations, combinations, exchange of  shares or the  like, the type  and
number  of shares or  securities subject to  the OPTION GRANTOR  Option, and the
purchase price per share provided in Section 1, shall be adjusted  appropriately
to  restore  to  OPTION HOLDER  its  rights  hereunder, including  the  right to
purchase from OPTION GRANTOR (or its successors) shares of OPTION GRANTOR Common
Stock (or such other shares or securities into which OPTION GRANTOR Common Stock
has been so changed)  representing the Option Shares  Percentage of the  Initial
Number of shares of OPTION GRANTOR Common Stock for the aggregate Exercise Price
calculated as of the date of this Agreement as provided in Section 1.
 
    13.    RESTRICTIVE LEGENDS.   Each  certificate representing  OPTION GRANTOR
Shares issued to  OPTION HOLDER  hereunder, and  OPTION HOLDER  Shares, if  any,
delivered   to  OPTION  GRANTOR  at  a   Closing,  shall  include  a  legend  in
substantially the following form:
 
    THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN  REGISTERED
    UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES OR
    BLUE  SKY LAWS, AND MAY BE REOFFERED OR SOLD ONLY IF SO REGISTERED OR IF
    AN EXEMPTION FROM  SUCH REGISTRATION IS  AVAILABLE. SUCH SECURITIES  ARE
    ALSO  SUBJECT TO ADDITIONAL RESTRICTIONS ON TRANSFER AS SET FORTH IN THE
    OPTION HOLDER STOCK OPTION  AND TRIGGER PAYMENT  AGREEMENT, DATED AS  OF
    NOVEMBER  10, 1995, A COPY OF WHICH MAY BE OBTAINED FROM THE ISSUER UPON
    REQUEST.
 
It is understood and agreed that:
 
                                      D-11
<PAGE>
        (i) the reference to the resale  restrictions of the Securities Act  and
    state  securities or Blue Sky  laws in the above  legend shall be removed by
    delivery of  substitute  certificate(s)  without such  reference  if  OPTION
    HOLDER  or OPTION GRANTOR, as  the case may be,  shall have delivered to the
    other party a copy of a letter from  the staff of the SEC, or an opinion  of
    counsel,  in  form and  substance satisfactory  to the  other party,  to the
    effect that such legend is not  required for purposes of the Securities  Act
    or such laws;
 
        (ii)  the reference  to the  provisions to  this Agreement  in the above
    legend shall be  removed by  delivery of  substitute certificate(s)  without
    such  reference if  the shares have  been sold or  transferred in compliance
    with the provisions of  this Agreement and under  circumstances that do  not
    require the retention of such reference; and
 
       (iii)  the legend shall be  removed in its entirety  if the conditions in
    the preceding clauses (i) and (ii) are both satisfied.
 
In addition, such certificates shall bear any other legend as may be required by
law. Certificates  representing  shares sold  in  a registered  public  offering
pursuant  to Section 11  shall not be required  to bear the  legend set forth in
this Section 13.
 
    14.  BINDING EFFECT; NO ASSIGNMENT; NO THIRD PARTY BENEFICIARIES.
 
        (a) This Agreement shall be binding upon and inure to the benefit of the
    parties hereto and their respective successors and permitted assigns.
 
        (b) Except as  expressly provided  for in this  Agreement, neither  this
    Agreement  nor  the  rights  or  obligations  of  either  party  hereto  are
    assignable, except by operation of law,  or with the written consent of  the
    other party.
 
        (c) Nothing contained in this Agreement, express or implied, is intended
    to confer upon any person other than the parties hereto and their respective
    successors  and  permitted  assigns any  rights  or remedies  of  any nature
    whatsoever by reason of this Agreement.
 
        (d) Any  Restricted  Shares sold  by  a  party in  compliance  with  the
    provisions  of Section 11 shall, upon consummation  of such sale, be free of
    the restrictions  imposed with  respect to  such shares  by this  Agreement,
    unless  and  until  such  party shall  repurchase  or  otherwise  become the
    beneficial owner of such shares, and any transferee of such shares shall not
    be entitled to the registration rights of such party.
 
    15.  SPECIFIC PERFORMANCE.  The  parties hereto agree that irreparable  harm
would  occur in the event that any of  the provisions of this Agreement were not
performed in accordance with their  specified terms or were otherwise  breached.
It  is  accordingly agreed  that  the parties  hereto  shall be  entitled  to an
injunction or injunctions to prevent breaches  of this Agreement and to  enforce
specifically  the terms and provisions hereof in  any court of the United States
or any state having jurisdiction, this being in addition to any other remedy  to
which they are entitled at law or equity.
 
    16.  VALIDITY.
 
        (a)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement shall  not affect  the  validity or  enforceability of  the  other
    provisions of this Agreement, which shall remain in full force and effect.
 
        (b)  In  the event  any  court or  other  competent authority  holds any
    provisions of this Agreement to be null, void or unenforceable, the  parties
    hereto  shall  negotiate in  good  faith the  execution  and delivery  of an
    amendment to this Agreement in order, as nearly as possible, to  effectuate,
    to  the  extent permitted  by law,  the  intent of  the parties  hereto with
    respect to such provision and the economic effects thereof.
 
        (c) Subject to Section 5, if for any reason any such court or regulatory
    agency determines that OPTION HOLDER is not permitted to acquire, or  OPTION
    GRANTOR is not permitted to
 
                                      D-12
<PAGE>
    repurchase  pursuant  to Section  8,  the full  number  of shares  of OPTION
    GRANTOR Common  Stock provided  in Section  1  hereof (as  the same  may  be
    adjusted),  it is  the express intention  of OPTION GRANTOR  to allow OPTION
    HOLDER to acquire  or to require  OPTION GRANTOR to  repurchase such  lesser
    number of shares as may be permissible without any amendment or modification
    hereof.
 
        (d)  Each  party  agrees  that,  should  any  court  or  other competent
    authority hold any provision  of this Agreement or  part hereof to be  null,
    void  or unenforceable, or  order any party to  take any action inconsistent
    herewith, or not take any action required herein, the other party shall  not
    be  entitled to specific performance of such  provision or part hereof or to
    any other remedy,  including but not  limited to money  damages, for  breach
    hereof  or of any  other provision of  this Agreement or  part hereof as the
    result of such holding or order.
 
    17.  NOTICES.   All notices and other  communications hereunder shall be  in
writing and shall be deemed given if (a) delivered personally, or (b) if sent by
overnight courier service (receipt confirmed in writing), or (c) if delivered by
facsimile  transmission (with receipt  confirmed), or (d)  five days after being
mailed by registered or certified mail (return receipt requested) to the parties
in each case to the following addresses (or at such other address for a party as
shall be specified by like notice):
 
    A.  If to OPTION HOLDER, to:
       WPL Holdings, Inc.
       222 West Washington Avenue
       Madison, Wisconsin 53703
       Attention: Erroll B. Davis, Jr.
       Fax: (608) 252-5059
       with a copy to:
       Foley & Lardner
       777 East Wisconsin Avenue
       Milwaukee, Wisconsin 53202-5367
       Attention: Benjamin F. Garmer, III, Esq.
       Fax: (414) 297-4900
 
    B.  If to OPTION GRANTOR, to:
       IES Industries Inc.
       IES Tower
       200 First Street S.E.
       Cedar Rapids, Iowa 52401
       Attention: Lee Liu
       Fax: (319) 398-4204
       with a copy to:
       Winthrop, Stimson, Putnam & Roberts
       One Battery Park Plaza
       New York, New York 10004-1490
       Attention: Stephen R. Rusmisel, Esq.
       Fax: (212) 858-1500
 
                                      D-13
<PAGE>
    18.  GOVERNING LAW.   This Agreement shall be  governed by and construed  in
accordance  with the laws of the State of Delaware applicable to agreements made
and to be performed entirely within such State and without regard to its  choice
of law principles or to any requirement as to jurisdiction or service of process
contained in Section 2708 of Title 6 of the Delaware Code.
 
    19.  INTERPRETATION.
        (a)  When reference is  made in this Agreement  to Articles, Sections or
    Exhibits, such reference shall be to an Article, Section or Exhibit of  this
    Agreement, as the case may be, unless otherwise indicated.
 
        (b)  The table of contents and  headings contained in this Agreement are
    for reference  purposes and  shall not  affect  in any  way the  meaning  or
    interpretation of the Agreement.
 
        (c) Whenever the words "include," "includes," or "including" are used in
    this  Agreement, they shall be  deemed to be followed  by the words "without
    limitation."
 
        (d) Whenever "or" is used in this Agreement it shall be construed in the
    nonexclusive sense.
 
    20.  COUNTERPARTS; EFFECT.   This Agreement may be  executed in one or  more
counterparts,  each of which shall be deemed to be an original, but all of which
shall constitute one and the same agreement.
 
    21.   AMENDMENTS; WAIVER.   This  Agreement may  be amended  by the  parties
hereto  and the terms and conditions hereof  may be waived only by an instrument
in writing signed on behalf of each of the parties hereto, or, in the case of  a
waiver, by an instrument signed on behalf of the party waiving compliance.
 
    22.   EXTENSION OF TIME PERIODS.   The time periods for exercises of certain
rights under Sections 2, 7 and 8 shall be extended (but in no event by more than
six months):
 
        (a) to the extent necessary to  obtain all regulatory approvals for  the
    exercise  of such  rights, and for  the expiration of  all statutory waiting
    periods; and
 
        (b) to the extent necessary to  avoid any liability under Section  16(b)
    of the Exchange Act by reason of such exercise.
 
    IN  WITNESS WHEREOF,  the parties  hereto have  caused this  Agreement to be
executed by their respective duly authorized officers as of the date first above
written.
 
                                          IES INDUSTRIES INC.
 
                                          By: /s/ LEE LIU
 
                                          --------------------------------------
                                          Name: Lee Liu
                                          Title: Chairman of the Board,
                                          President
                                               and Chief Executive Officer
 
                                          WPL HOLDINGS, INC.
 
                                          By: /s/ ERROLL B. DAVIS, JR.
 
                                          --------------------------------------
                                          Name: Erroll B. Davis, Jr.
                                          Title: President and Chief Executive
                                                 Officer
 
                                      D-14
<PAGE>
                                                                         ANNEX E
 
                   OPTION GRANTOR/OPTION HOLDER STOCK OPTION
                         AND TRIGGER PAYMENT AGREEMENT
 
    This STOCK OPTION AGREEMENT, dated as of November 10, 1995 (the "AGREEMENT")
by  and among IES Industries Inc., a corporation organized under the laws of the
State of Iowa ("OPTION GRANTOR" or the "COMPANY") and Interstate Power  Company,
a  corporation  organized  under the  laws  of  the State  of  Delaware ("OPTION
HOLDER").
 
                         W I T N E S S E T H  T H A T:
 
    WHEREAS, concurrently with  the execution  and delivery  of this  Agreement,
OPTION GRANTOR, OPTION HOLDER, WPL Holdings, Inc., a corporation organized under
the laws of the State of Wisconsin ("WPL"), WPLH Acquisition Co., a wholly-owned
subsidiary   of  WPL  organized  under  the  laws  of  the  State  of  Wisconsin
("ACQUISITION"), and  Interstate Power  Company,  a wholly-owned  subsidiary  of
OPTION  HOLDER organized under the laws of  the State of Wisconsin, are entering
into an Agreement and Plan of Merger, dated as of November 10, 1995, as  amended
(the "MERGER AGREEMENT"), which provides, INTER ALIA, upon the terms and subject
to the conditions thereof, for the merger of OPTION GRANTOR with and into WPL in
accordance with the laws of the States of Wisconsin and Iowa (the "IES MERGER"),
and  the  merger of  Acquisition with  and  into OPTION  HOLDER (or  a successor
thereto) in accordance with the laws of the States of Delaware and/or  Wisconsin
(the "INTERSTATE MERGER", and together with the IES Merger, the "MERGER");
 
    WHEREAS,  in connection with  the execution of  the Merger Agreement, OPTION
GRANTOR, OPTION HOLDER and WPL are entering into certain stock option agreements
dated as of the date hereof, of which this Agreement is one, whereby the parties
hereto grant each other an option with respect to certain shares of each other's
common stock on the terms and subject  to the conditions set forth therein  (the
"STOCK OPTION AGREEMENTS"); and
 
    WHEREAS,  as a  condition to OPTION  HOLDER's willingness to  enter into the
Merger Agreement, OPTION  HOLDER has  requested that OPTION  GRANTOR agree,  and
OPTION  GRANTOR has so agreed, to grant  to OPTION HOLDER an option with respect
to certain shares of OPTION GRANTOR's common stock, on the terms and subject  to
the conditions set forth herein;
 
    NOW,  THEREFORE, to induce OPTION HOLDER  to enter into the Merger Agreement
and certain  of  the  Stock  Option Agreements,  and  in  consideration  of  the
representations,  warranties, covenants and agreements  contained herein, in the
Merger Agreement and in the Stock Option Agreements to which OPTION GRANTOR  and
OPTION  HOLDER are parties,  the parties hereto, intending  to be legally bound,
hereby agree as follows:
 
    1.  GRANT OF OPTION.
 
        (a) Subject  to  the receipt  of  all regulatory  approvals  and  orders
    required  by  OPTION GRANTOR  as  set forth  in  Section 5.4(c)  of  the IES
    Disclosure Schedule to  the Merger  Agreement and  by OPTION  HOLDER as  set
    forth  in Section 6.4(c) of the Interstate Disclosure Schedule to the Merger
    Agreement, OPTION GRANTOR hereby grants OPTION HOLDER an irrevocable  option
    (the  "OPTION  GRANTOR OPTION")  to purchase  up to  that number  of shares,
    subject to  adjustment  as  provided  in Section  12  (the  "OPTION  GRANTOR
    SHARES"),  of common  stock, no  par value,  of OPTION  GRANTOR (the "OPTION
    GRANTOR  COMMON  STOCK")   equal  to  a   percentage  (the  "OPTION   SHARES
    PERCENTAGE"), which Option Shares Percentage is equal to the OPTION HOLDER's
    Participation  Percentage as defined  below in subsection  (e), of 5,861,115
    shares of OPTION GRANTOR Common Stock  (being 19.9% of the number of  shares
    of OPTION
 
                                      E-1
<PAGE>
    GRANTOR  Common Stock  issued and outstanding  as of November  10, 1995 (the
    "INITIAL NUMBER") in the manner set  forth below, at a price (the  "EXERCISE
    PRICE")  per OPTION GRANTOR  Share of $26.7125  (which is equal  to the Fair
    Market Value (as defined below)  of an OPTION GRANTOR  Share as of the  date
    hereof).
 
        (b)  The Exercise Price shall be  payable, at OPTION HOLDER's option, as
    follows:
 
           (i) in cash, or
 
           (ii) subject  to the  receipt of  all approvals  of any  Governmental
       Authority  required for OPTION  GRANTOR to acquire,  and OPTION HOLDER to
       issue, the OPTION HOLDER Shares (as defined below) from OPTION HOLDER, in
       shares of common stock, $3.50 par value, of OPTION HOLDER ("OPTION HOLDER
       SHARES"),
 
    in either case in accordance with Section 4 hereof.
 
        (c) Notwithstanding  the foregoing,  in  no event  shall the  number  of
    OPTION  GRANTOR Shares  for which the  OPTION GRANTOR  Option is exercisable
    exceed the product of the Option  Shares Percentage and the Initial  Number,
    subject to adjustment as provided in Section 12.
 
        (d)  As used herein, the  "FAIR MARKET VALUE" of  any share shall be the
    average of the  daily closing sales  price for  such share on  the New  York
    Stock  Exchange (the "NYSE") during  the ten NYSE trading  days prior to the
    fifth NYSE trading day preceding  the date such Fair  Market Value is to  be
    determined.
 
        (e)  For purposes of this  Agreement the term "PARTICIPATION PERCENTAGE"
    shall have  the  same  meaning  as  in  Section  10.3(f)(i)  of  the  Merger
    Agreement,  except that  the numerator  and denominator  shall be calculated
    based on the number of  shares of WPL Common  Stock which would be  issuable
    (or,  in the case of  WPL, retained by its  shareholders) on a fully diluted
    basis had the Effective Time occurred as  of the date on which the  Exercise
    Notice  is delivered under Section 2 hereof  or the date on which demand for
    the Trigger Payment (as defined herein) is given under Section 5 hereof,  as
    the  case may be. Other capitalized terms used herein but not defined herein
    shall have the meanings set forth in the Merger Agreement.
 
    2.  EXERCISE OF OPTION.
 
        (a) The OPTION  GRANTOR Option  may be  exercised by  OPTION HOLDER,  in
    whole  or  in part,  at  any time  or  from time  to  time after  the Merger
    Agreement becomes  terminable by  OPTION  HOLDER under  circumstances  which
    could  entitle OPTION HOLDER  to a termination fee  under Section 10.3(a) of
    the  Merger  Agreement  (provided  that  the  events  specified  in  Section
    10.3(a)(ii)(A)  of the  Merger Agreement  shall have  occurred, although the
    events specified in Section 10.3(a)(ii)(B) thereof need not have  occurred),
    or Section 10.3(b) of the Merger Agreement (regardless of whether the Merger
    Agreement  is actually terminated  or whether there occurs  a closing of any
    Business Combination involving a Target Party or a closing by which a Target
    Party becomes a Subsidiary),  any such event by  which the Merger  Agreement
    becomes  so  terminable  by OPTION  HOLDER  being  referred to  herein  as a
    "TRIGGER EVENT").
 
         (b)(i) OPTION GRANTOR shall notify OPTION HOLDER promptly in writing of
       the occurrence of any Trigger Event, it being understood that the  giving
       of such notice by OPTION GRANTOR shall not be a condition to the right of
       OPTION HOLDER to exercise the OPTION GRANTOR Option.
 
           (ii) In the event OPTION HOLDER wishes to exercise the OPTION GRANTOR
       Option,  OPTION HOLDER shall deliver to OPTION GRANTOR written notice (an
       "EXERCISE NOTICE") specifying the total  number of OPTION GRANTOR  Shares
       it wishes to purchase.
 
          (iii)  Upon  the giving  by  OPTION HOLDER  to  OPTION GRANTOR  of the
       Exercise Notice  and  the tender  of  the applicable  aggregate  Exercise
       Price, OPTION HOLDER, to the extent permitted by law and OPTION GRANTOR's
       organizational documents, and provided
 
                                      E-2
<PAGE>
       that  the conditions to  OPTION GRANTOR's obligation  to issue the OPTION
       GRANTOR Shares to  OPTION HOLDER hereunder  set forth in  Section 3  have
       been  satisfied or waived, shall be deemed  to be the holder of record of
       the OPTION GRANTOR  Shares issuable upon  such exercise,  notwithstanding
       that  the stock transfer books of OPTION  GRANTOR shall then be closed or
       that certificates representing such OPTION GRANTOR Shares shall not  then
       be actually delivered to OPTION HOLDER.
 
          (iv) Each closing of a purchase of OPTION GRANTOR Shares (a "CLOSING")
       shall  occur at a  place, on a date,  and at a  time designated by OPTION
       HOLDER in an Exercise Notice delivered  at least two business days  prior
       to the date of the Closing.
 
        (c) The OPTION GRANTOR Option shall terminate upon the earliest to occur
    of:
 
           (i) the Effective Time of the Merger;
 
           (ii) the termination of the Merger Agreement pursuant to Section 10.1
       thereof,  other than under circumstances  which also constitute a Trigger
       Event under this Agreement;
 
          (iii) 180 days following any termination of the Merger Agreement  upon
       or during the continuance of a Trigger Event (or if, at the expiration of
       such  180 day  period, the OPTION  GRANTOR Option cannot  be exercised by
       reason of any applicable judgment, decree, order, law or regulation,  ten
       business  days after such impediment to  exercise shall have been removed
       or shall have become  final and not  subject to appeal,  but in no  event
       under this clause (iii) later than May 10, 1998); and
 
          (iv)  payment by  OPTION GRANTOR of  the Trigger Payment  set forth in
       Section 5 of this Agreement to OPTION HOLDER.
 
        (d) Notwithstanding the foregoing, the OPTION GRANTOR Option may not  be
    exercised  if  (i)  OPTION  HOLDER  is in  material  breach  of  any  of its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in  this Agreement or in  the Merger Agreement,  or
    (ii) a Trigger Payment has been paid pursuant to Section 5 of this Agreement
    or demand therefor has been made and not withdrawn.
 
    3.   CONDITIONS TO CLOSING.   The obligation of  OPTION GRANTOR to issue the
OPTION GRANTOR Shares to  OPTION HOLDER hereunder is  subject to the  conditions
that
 
        (a)  all waiting periods,  if any, under  the HSR Act  applicable to the
    issuance and acquisition of the  OPTION GRANTOR Shares hereunder shall  have
    expired or have been terminated;
 
        (b)  the OPTION GRANTOR  Shares, and any OPTION  HOLDER Shares which are
    issued in  payment of  the  Exercise Price,  shall  have been  approved  for
    listing on the NYSE subject only to official notice of issuance;
 
        (c)   all  consents,   approvals,  orders   or  authorizations   of,  or
    registrations, declarations or  filings with,  any federal,  state or  local
    administrative  agency  or  commission  or  other  federal,  state  or local
    Governmental Authority, if any, required in connection with the issuance  by
    OPTION  GRANTOR and the  acquisition by OPTION HOLDER  of the OPTION GRANTOR
    Shares hereunder  shall  have  been obtained  or  made,  including,  without
    limitation,  the approval of the  SEC under Sections 9  and 10 of the Public
    Utility Holding  Company Act  of  1935, as  amended  (the "1935  ACT"),  the
    approval  of the Iowa Utilities Board of  the issuance of the OPTION GRANTOR
    Shares by OPTION GRANTOR and, if  applicable, the acquisition of the  OPTION
    GRANTOR  Shares by  OPTION HOLDER,  and the  approval of  the Iowa Utilities
    Board, the Minnesota Public Utilities  Commission and the Illinois  Commerce
    Commission  of the acquisition of the OPTION GRANTOR Shares by OPTION HOLDER
    and, if applicable, the acquisition by  OPTION GRANTOR of the OPTION  HOLDER
    Shares constituting the Exercise Price hereunder; and
 
                                      E-3
<PAGE>
        (d)  no preliminary or permanent injunction  or other order by any court
    of competent jurisdiction prohibiting or otherwise restraining such issuance
    shall be in effect.
 
The condition set forth in paragraph (b) above may be waived by OPTION  GRANTOR,
in the case of OPTION HOLDER Shares, and by OPTION HOLDER, in the case of OPTION
GRANTOR Shares, in the sole discretion of the waiving party.
 
    4.  CLOSING.  At any Closing,
 
        (a)  OPTION GRANTOR  shall deliver  to OPTION  HOLDER or  its designee a
    single certificate  in definitive  form representing  the number  of  OPTION
    GRANTOR  Shares designated  by OPTION  HOLDER in  its Exercise  Notice, such
    certificate to be registered in  the name of OPTION  HOLDER and to bear  the
    legend set forth in Section 13; and
 
        (b)  OPTION HOLDER shall  deliver to OPTION  GRANTOR the aggregate price
    for the OPTION GRANTOR Shares so designated and being purchased by
 
           (i) wire transfer of immediately  available funds or certified  check
       or bank check, or
 
           (ii)  subject to  the condition  in Section  1(b)(ii), delivery  of a
       certificate or  certificates representing  the  number of  OPTION  HOLDER
       Shares being issued by OPTION HOLDER in consideration thereof, determined
       in accordance with Section 4(c).
 
        (c)  In  the event  that OPTION  HOLDER issues  OPTION HOLDER  Shares to
    OPTION GRANTOR in consideration of OPTION GRANTOR Shares pursuant to Section
    4(b)(ii), the number of OPTION HOLDER Shares to be so issued shall be  equal
    to the quotient obtained by dividing:
 
           (i)  the  product of  (x) the  number of  OPTION GRANTOR  Shares with
       respect to which the OPTION GRANTOR Option is being exercised and (y) the
       Exercise Price, by
 
           (ii) the Fair Market Value of the OPTION HOLDER Shares as of the date
       immediately preceding the date the Exercise Notice is delivered to OPTION
       GRANTOR.
 
        (d) OPTION GRANTOR  shall pay  all expenses,  and any  and all  Federal,
    state  and local taxes and  other charges that may  be payable in connection
    with the preparation, issue  and delivery of  stock certificates under  this
    Section 4.
 
    5.  TRIGGER PAYMENT.
 
        (a)   TRIGGER PAYMENT.  Subject to  the provisions of Section 10.3(e) of
    the Merger  Agreement,  if a  Trigger  Event  shall have  occurred  and  any
    regulatory approval or order required for the issuance by OPTION GRANTOR, or
    the  acquisition by OPTION HOLDER, of  the OPTION GRANTOR Option pursuant to
    Section 1 hereof shall not have been obtained, OPTION HOLDER shall have  the
    right  to receive, and OPTION GRANTOR shall  pay to OPTION HOLDER, an amount
    (the "TRIGGER PAYMENT") equal to the product of
 
           (i) the maximum number of OPTION GRANTOR Shares that would have  been
       subject  to purchase by OPTION HOLDER upon exercise of the OPTION GRANTOR
       Option pursuant  to  Sections 1  and  2  hereof if  all  such  regulatory
       approvals or orders had been obtained, and
 
           (ii)  the difference between  (A) the Market/Offer  Price (as defined
       herein), determined as  of the  date on which  notice of  demand for  the
       Trigger  Payment is  given by OPTION  HOLDER, and (B)  the Exercise Price
       (but only if such Market/Offer Price is higher than such Exercise Price).
 
    Demand for the Trigger Payment shall  be given by notice in accordance  with
    the  provisions of Section 17  hereof. The Trigger Payment  shall be paid to
    OPTION HOLDER by OPTION
 
                                      E-4
<PAGE>
    GRANTOR on  the  Payment Date  (as  defined  herein), by  wire  transfer  of
    immediately  available funds  to an account  to be designated  in writing by
    OPTION HOLDER not less than two business days before the Payment Date.
 
        (b)  PAYMENT DATE.  For purposes of this Section 5, "PAYMENT DATE" means
    the date on which termination fees are required to be paid by OPTION GRANTOR
    to OPTION HOLDER under Section  10.3(a) or 10.3(b), as  the case may be,  of
    the  Merger Agreement  as a  result of the  occurrence of  the Trigger Event
    referred to in subsection (a) of this Section 5.
 
        (c)  CERTAIN CONDITIONS.  OPTION GRANTOR shall have no obligation to pay
    the Trigger Payment if  OPTION HOLDER is  in material breach  of any of  its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in this Agreement or in the Merger Agreement.
 
    6.    REPRESENTATIONS  AND WARRANTIES  OF  OPTION GRANTOR.    OPTION GRANTOR
represents and warrants to OPTION HOLDER that
 
        (a) except as set forth in Section 5.4(a) of the IES Disclosure Schedule
    to the  Merger  Agreement,  OPTION  GRANTOR  has  the  corporate  power  and
    authority  to enter  into this  Agreement and  to carry  out its obligations
    hereunder, subject  in the  case of  the repurchase  of the  OPTION  GRANTOR
    Shares  pursuant to  Section 8(a)  to applicable  law and  the provisions of
    OPTION GRANTOR's Articles of Incorporation, as amended (the "OPTION  GRANTOR
    ARTICLES");
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION GRANTOR, and, assuming the due authorization, execution and  delivery
    hereof  by  OPTION  HOLDER  and  the  receipt  of  all  required  regulatory
    approvals, constitutes a  valid and  binding obligation  of OPTION  GRANTOR,
    enforceable  against OPTION GRANTOR in accordance  with its terms, except as
    may be limited by applicable bankruptcy, insolvency, reorganization or other
    similar laws affecting the enforcement  of creditors' rights generally,  and
    except  that  the  availability of  equitable  remedies,  including specific
    performance, may be subject to the discretion of any court before which  any
    proceeding therefor may be brought;
 
        (c) OPTION GRANTOR has taken all necessary corporate action to authorize
    and  reserve for issuance  and to permit  it to issue,  upon exercise of the
    OPTION GRANTOR Option,  and at all  times from the  date hereof through  the
    expiration  of the  OPTION GRANTOR  Option will  have reserved,  the Initial
    Number of authorized and unissued  OPTION GRANTOR Shares, such amount  being
    subject  to adjustment as provided  in Section 12, all  of which, upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d) upon delivery of the OPTION GRANTOR Shares to OPTION HOLDER upon the
    exercise of the OPTION GRANTOR Option, OPTION HOLDER will acquire the OPTION
    GRANTOR  Shares free and  clear of all  claims, liens, charges, encumbrances
    and security interests of any nature whatsoever;
 
        (e) except as described in Section 5.4(b) of the IES Disclosure Schedule
    to the Merger  Agreement, the execution  and delivery of  this Agreement  by
    OPTION  GRANTOR does not, and, subject to compliance with applicable law and
    the OPTION GRANTOR  Articles with respect  to the repurchase  of the  OPTION
    GRANTOR  Shares pursuant to Section 8(a), the consummation by OPTION GRANTOR
    of the transactions contemplated hereby will not violate, conflict with,  or
    result  in a breach  of any provision  of, or constitute  a default (with or
    without notice  or  a lapse  of  time, or  both)  under, or  result  in  the
    termination  of, or accelerate  the performance required by,  or result in a
    right of termination, cancellation, or acceleration of any obligation or the
    loss of  a  material benefit  under,  or the  creation  of a  lien,  pledge,
    security interest or other encumbrance on
 
                                      E-5
<PAGE>
    assets  (any  such  conflict,  violation,  default,  right  of  termination,
    cancellation, acceleration, loss or creation, hereinafter a "VIOLATION")  of
    OPTION GRANTOR or any of its Subsidiaries, pursuant to
 
           (i)  any provision  of the OPTION  GRANTOR Articles or  the Bylaws of
       OPTION GRANTOR,
 
           (ii) any provisions of any  material loan or credit agreement,  note,
       mortgage,  indenture, lease, benefit plan or other agreement, obligation,
       instrument,  permit,  concession,  franchise  or  license  (any  of   the
       foregoing  in effect on the date hereof  being referred to as a "MATERIAL
       CONTRACT") of OPTION GRANTOR or its subsidiaries or to which any of  them
       is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable  to OPTION  GRANTOR or  its properties  or  assets,
       which  Violation,  in the  case  of each  clauses  (ii) and  (iii), could
       reasonably be expected to have an OPTION GRANTOR Material Adverse  Effect
       (except  that  no  representation  or warranty  is  given  concerning any
       Violation of a Material Contract with respect to the repurchase of OPTION
       GRANTOR Shares pursuant to Section 8(a));
 
        (f) except as described in Section 5.4(c) of the IES Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of this Agreement by  OPTION GRANTOR does not,  and the performance of  this
    Agreement  by  OPTION  GRANTOR  will  not,  require  any  consent, approval,
    authorization or permit of, filing with or notification to, any Governmental
    Authority;
 
        (g) none of OPTION  GRANTOR, any of its  affiliates or anyone acting  on
    its  or their  behalf, has  issued, sold or  offered any  security of OPTION
    GRANTOR to any person under circumstances that would cause the issuance  and
    sale  of OPTION  GRANTOR Shares,  as contemplated  by this  Agreement, to be
    subject to the registration requirements of the Securities Act as in  effect
    on  the date  hereof, and,  assuming the  representations and  warranties of
    OPTION HOLDER contained in Section 7(g) are true and correct, the  issuance,
    sale  and delivery  of the OPTION  GRANTOR Shares hereunder  would be exempt
    from the registration and prospectus delivery requirements of the Securities
    Act, as in effect on the date hereof (and OPTION GRANTOR shall not take  any
    action  which would cause the issuance, sale, and delivery of OPTION GRANTOR
    Shares hereunder not to be exempt from such requirements); and
 
        (h) any OPTION HOLDER Shares acquired pursuant to this Agreement will be
    acquired for OPTION GRANTOR's own account, for investment purposes only, and
    will  not  be  acquired  by  OPTION  GRANTOR  with  a  view  to  the  public
    distribution  thereof  in  violation  of  any  applicable  provision  of the
    Securities Act.
 
    7.   REPRESENTATIONS  AND  WARRANTIES  OF  OPTION  HOLDER.    OPTION  HOLDER
represents and warrants to OPTION GRANTOR that
 
        (a)  except as set forth in Schedule 6.4(a) of the Interstate Disclosure
    Schedule to the Merger Agreement, OPTION HOLDER has the corporate power  and
    authority  to enter  into this  Agreement and  to carry  out its obligations
    hereunder;
 
        (b) this Agreement has been duly  and validly executed and delivered  by
    OPTION  HOLDER and, assuming  the due authorization,  execution and delivery
    hereof by  OPTION  GRANTOR  and  the  receipt  of  all  required  regulatory
    approvals,  constitutes  a valid  and binding  obligation of  OPTION HOLDER,
    enforceable against OPTION HOLDER in  accordance with its respective  terms,
    except   as   may   be  limited   by   applicable   bankruptcy,  insolvency,
    reorganization,  or  other  similar   laws  affecting  the  enforcement   of
    creditors'  rights generally, and except  that the availability of equitable
    remedies, including specific performance, may  be subject to the  discretion
    of any court before which any proceeding may be brought;
 
                                      E-6
<PAGE>
        (c)  prior to any  delivery of OPTION HOLDER  Shares in consideration of
    the purchase of OPTION  GRANTOR Shares pursuant  hereto, OPTION HOLDER  will
    have  taken all necessary corporate action  to authorize for issuance and to
    permit it  to issue  such OPTION  HOLDER Shares,  all of  which, upon  their
    issuance  and delivery in accordance with  the terms of this Agreement, will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d) upon any delivery of such OPTION HOLDER Shares to OPTION GRANTOR  in
    consideration  of  the purchase  of OPTION  GRANTOR Shares  pursuant hereto,
    OPTION GRANTOR will acquire the OPTION  HOLDER Shares free and clear of  all
    claims,  liens, charges, encumbrances  and security interests  of any nature
    whatsoever;
 
        (e) except as described in  Section 6.4(b) of the Interstate  Disclosure
    Schedule  to  the  Merger  Agreement, the  execution  and  delivery  of this
    Agreement by OPTION HOLDER does not,  and the consummation by OPTION  HOLDER
    of  the transactions contemplated hereby will not violate, conflict with, or
    result in the breach of any provision  of, or constitute a default (with  or
    without  notice  or  a lapse  of  time, or  both)  under, or  result  in any
    Violation by OPTION HOLDER or any of its Subsidiaries, pursuant to
 
           (i) any  provision of  the  Articles of  Incorporation or  Bylaws  of
       OPTION HOLDER,
 
           (ii)   any  Material  Contract  of  OPTION   HOLDER  or  any  of  its
       subsidiaries or to which any of them is a party, or
 
          (iii) any judgment,  order, decree, statute,  law, ordinance, rule  or
       regulation applicable to OPTION HOLDER or its properties or assets,
 
    which Violation, in the case of each of clauses (ii) or (iii), would have an
    OPTION HOLDER Material Adverse Effect;
 
        (f)  except as described in Section  6.4(c) of the Interstate Disclosure
    Schedule to the Merger Agreement or Section 1 or 3 hereof, the execution and
    delivery of this Agreement by OPTION  HOLDER does not, and the  consummation
    by  OPTION HOLDER of the transactions  contemplated hereby will not, require
    any  consent,  approval,  authorization  or   permit  of,  filing  with   or
    notification to, any Governmental Authority; and
 
        (g)  any  OPTION GRANTOR  Shares acquired  upon  exercise of  the OPTION
    GRANTOR Option  will  be  acquired  for OPTION  HOLDER's  own  account,  for
    investment  purposes only and will not be,  and the OPTION GRANTOR Option is
    not being, acquired by OPTION HOLDER with a view to the public  distribution
    thereof, in violation of any applicable provision of the Securities Act.
 
    8.  CERTAIN REPURCHASES.
 
        (a)   OPTION HOLDER "PUT".   At the request  of OPTION HOLDER by written
    notice (x) at any time during which the OPTION GRANTOR Option is exercisable
    pursuant to  Section 2  (the "REPURCHASE  PERIOD"), OPTION  GRANTOR (or  any
    successor  entity thereof) shall, if permitted by applicable law, the OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase  from  OPTION HOLDER  all or  any portion  of the  OPTION GRANTOR
    Option, at the price  set forth in  subparagraph (i) below,  or, (y) at  any
    time prior to May 10, 1997 (provided that such date shall be extended to May
    10, 1998 under the circumstances where the date after which either party may
    terminate  the Merger  Agreement pursuant to  Section 10.1(b)  of the Merger
    Agreement has  been  extended to  May  10,  1998), OPTION  GRANTOR  (or  any
    successor  entity thereof) shall, if permitted by applicable law, the OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase  from  OPTION HOLDER  all or  any portion  of the  OPTION GRANTOR
    Shares purchased by OPTION HOLDER pursuant to the OPTION GRANTOR Option,  at
    the price set forth in subparagraph (ii) below:
 
                                      E-7
<PAGE>
         (i)(A)  The  difference between  the  "Market/Offer Price"  (as defined
       below) for shares of  OPTION GRANTOR Common Stock  as of the date  OPTION
       HOLDER  gives  notice of  its intent  to exercise  its rights  under this
       Section 8 and  the Exercise  Price, multiplied  by the  number of  OPTION
       GRANTOR  Shares  purchasable pursuant  to the  OPTION GRANTOR  Option (or
       portion thereof with  respect to  which OPTION HOLDER  is exercising  its
       rights  under  this Section  8), but  only if  the Market/Offer  Price is
       greater than the Exercise Price.
 
           (B) For purposes of this Agreement, "MARKET/OFFER PRICE" shall  mean,
       as  of any date, the higher of (I) the price per share offered as of such
       date pursuant to any tender or exchange offer or other offer with respect
       to a Business Combination  involving OPTION GRANTOR  as the Target  Party
       which  was made prior to such date  and not terminated or withdrawn as of
       such date and (II) the Fair  Market Value of OPTION GRANTOR Common  Stock
       as of such date.
 
        (ii)(A)  The product of  (I) the sum  of (a) the  Exercise Price paid by
       OPTION HOLDER per OPTION  GRANTOR Share acquired  pursuant to the  OPTION
       GRANTOR  Option, and  (b) the  difference between  the "OFFER  PRICE" (as
       defined below) and  the Exercise Price,  but only if  the Offer Price  is
       greater  than the Exercise  Price, and (II) the  number of OPTION GRANTOR
       Shares so to be repurchased pursuant to this Section 8.
 
           (B) For purposes of this clause (ii), the "OFFER PRICE" shall be  the
       highest price per share offered pursuant to a tender or exchange offer or
       other  Business Combination offer involving  OPTION GRANTOR as the Target
       Party during the Repurchase Period prior to the delivery by OPTION HOLDER
       of a notice of repurchase.
 
        (b)  REDELIVERY OF  OPTION HOLDER SHARES.   If OPTION HOLDER shall  have
    previously  elected  to  purchase  OPTION  GRANTOR  Shares  pursuant  to the
    exercise of the OPTION GRANTOR Option by the issuance and delivery of OPTION
    HOLDER Shares, then OPTION GRANTOR shall, if so requested by OPTION  HOLDER,
    in  fulfillment of its obligation pursuant to Section 8(a)(y) (that is, with
    respect to the Exercise Price only and without limitation to its  obligation
    to pay additional consideration under clause (b) of Section 8(a)(ii)(A)(I)),
    redeliver  the certificates for such OPTION  HOLDER Shares to OPTION HOLDER,
    free and clear of all liens, claims, charges and encumbrances of any kind or
    nature whatsoever; PROVIDED, HOWEVER, that if  at any time less than all  of
    the  OPTION GRANTOR  Shares so  purchased by  OPTION HOLDER  pursuant to the
    OPTION GRANTOR Option are  to be repurchased by  OPTION GRANTOR pursuant  to
    Section  8(a)(y), then (i) OPTION GRANTOR shall be obligated to redeliver to
    OPTION HOLDER the same proportion of such OPTION HOLDER Shares as the number
    of OPTION GRANTOR Shares that OPTION GRANTOR is then obligated to repurchase
    bears to the number of OPTION GRANTOR Shares acquired by OPTION HOLDER  upon
    exercise  of the OPTION GRANTOR Option and (ii) OPTION HOLDER shall issue to
    OPTION GRANTOR  new certificates  representing  those OPTION  HOLDER  Shares
    which  are  not due  to be  redelivered  to OPTION  HOLDER pursuant  to this
    Section 8(b) to the extent that excess OPTION HOLDER Shares are included  in
    the certificates redelivered to OPTION HOLDER by OPTION GRANTOR.
 
        (c)   PAYMENT AND REDELIVERY OF OPTION GRANTOR OPTIONS OR SHARES. In the
    event OPTION  HOLDER  exercises its  rights  under this  Section  8,  OPTION
    GRANTOR  shall, within ten business days thereafter, pay the required amount
    to OPTION  HOLDER in  immediately available  funds and  OPTION HOLDER  shall
    surrender  to OPTION GRANTOR the OPTION GRANTOR Option or the certificate or
    certificates evidencing the OPTION GRANTOR Shares purchased by OPTION HOLDER
    pursuant hereto, and  OPTION HOLDER shall  warrant that it  owns the  OPTION
    GRANTOR  Option or such  shares and that  the OPTION GRANTOR  Option or such
    shares are then free  and clear of all  liens, claims, damages, charges  and
    encumbrances of any kind or nature whatsoever.
 
                                      E-8
<PAGE>
        (d)   OPTION HOLDER  "CALL".  If  OPTION HOLDER has  elected to purchase
    OPTION GRANTOR Shares pursuant to the exercise of the OPTION GRANTOR  Option
    by  the issuance and delivery of  OPTION HOLDER Shares, notwithstanding that
    OPTION HOLDER may  no longer  hold any such  OPTION GRANTOR  Shares or  that
    OPTION  HOLDER elects not to exercise its other rights under this Section 8,
    OPTION HOLDER may require, at any time or from time to time prior to May 10,
    1997 (provided that such date  shall be extended to  May 10, 1998 under  the
    circumstances  where the  date after  which either  party may  terminate the
    Merger Agreement pursuant  to Section  10.1(b) of the  Merger Agreement  has
    been  extended to May 10, 1998), OPTION GRANTOR to sell to OPTION HOLDER any
    such OPTION HOLDER  Shares at  the price  attributed to  such OPTION  HOLDER
    Shares pursuant to Section 4 plus interest at the rate of 8.75% per annum on
    such  amount from the Closing  Date relating to the  exchange of such OPTION
    HOLDER Shares pursuant to Section 4  to the Closing Date under this  Section
    8(d) less any dividends on such OPTION HOLDER Shares paid during such period
    or  declared and  payable to  stockholders of record  on a  date during such
    period.
 
        (e)  REPURCHASE PRICE REDUCED AT  OPTION HOLDER'S OPTION.  In the  event
    the repurchase price specified in Section 8(a) would subject the purchase of
    the  OPTION GRANTOR Option or the  OPTION GRANTOR Shares purchased by OPTION
    HOLDER pursuant to the OPTION GRANTOR  Option to a vote of the  shareholders
    of OPTION GRANTOR pursuant to applicable law or the OPTION GRANTOR Articles,
    then  OPTION HOLDER may, at its election,  reduce the repurchase price to an
    amount which would permit such repurchase  without the necessity for such  a
    shareholder vote.
 
    9.   VOTING  OF SHARES.   Following the date  hereof and prior  to the fifth
anniversary of the date  hereof (the "EXPIRATION DATE"),  each party shall  vote
any  shares of capital stock of the  other party acquired by such party pursuant
to this  Agreement ("RESTRICTED  SHARES"), including  any OPTION  HOLDER  Shares
issued  pursuant to  Section 1(b), or  otherwise beneficially  owned (within the
meaning of Rule 13d-3 promulgated under the Securities Exchange Act of 1934,  as
amended  (the "EXCHANGE ACT")), by such party on each matter submitted to a vote
of shareholders of  such other party  for and  against such matter  in the  same
proportion  as the vote of all other  shareholders of such other party are voted
(whether by proxy or otherwise) for and against such matter.
 
    10.  RESTRICTIONS ON TRANSFER.
 
        (a)  RESTRICTIONS ON  TRANSFER.  Prior to  the Expiration Date,  neither
    party shall, directly or indirectly, by operation of law or otherwise, sell,
    assign,  pledge, or otherwise  dispose of or  transfer any Restricted Shares
    beneficially owned by such party, other  than (i) pursuant to Section 8,  or
    (ii) in accordance with Section 10(b) or Section 11.
 
        (b)    PERMITTED  SALES.    Following  the  termination  of  the  Merger
    Agreement, a  party  shall  be  permitted  to  sell  any  Restricted  Shares
    beneficially  owned  by it  if such  sale is  made pursuant  to a  tender or
    exchange  offer  that  has  been  approved  or  recommended,  or   otherwise
    determined  to be fair to  and in the best  interests of the shareholders of
    the other party, by a majority of  the members of the Board of Directors  of
    such  other party, which majority shall  include a majority of directors who
    were directors prior to the announcement of such tender or exchange offer.
 
    11.  REGISTRATION RIGHTS.
 
        (a) Following  the termination  of the  Merger Agreement,  either  party
    hereto  that owns Restricted  Shares (a "DESIGNATED  HOLDER") may by written
    notice (the "REGISTRATION  NOTICE") to  the other  party (the  "REGISTRANT")
    request  the Registrant to register under the Securities Act all or any part
    of the Restricted Shares beneficially  owned by such Designated Holder  (the
    "REGISTRABLE   SECURITIES")  pursuant   to  a  bona   fide  firm  commitment
    underwritten public  offering,  in  which  the  Designated  Holder  and  the
    underwriters  shall  effect  as  wide  a  distribution  of  such Registrable
    Securities as is reasonably practicable and shall use their best efforts  to
    prevent any person
 
                                      E-9
<PAGE>
    (including any Group (as used in Rule 13d-5 under the Exchange Act)) and its
    affiliates   from  purchasing   through  such   offering  Restricted  Shares
    representing more than 1% of the  outstanding shares of common stock of  the
    Registrant on a fully diluted basis (a "PERMITTED OFFERING").
 
        (b)  The Registration Notice shall include a certificate executed by the
    Designated Holder and its  proposed managing underwriter, which  underwriter
    shall  be an investment banking firm  of nationally recognized standing (the
    "MANAGER"), stating that
 
           (i) they have a good faith intention to commence promptly a Permitted
       Offering, and
 
           (ii)  the  manager  in  good  faith  believes  that,  based  on   the
       then-prevailing   market  conditions,  it  will   be  able  to  sell  the
       Registrable Securities at a per share price equal to at least 80% of  the
       then Fair Market Value of such shares.
 
        (c)  The  Registrant (and/or  any person  designated by  the Registrant)
    shall thereupon have the option  exercisable by written notice delivered  to
    the  Designated Holder  within ten  business days  after the  receipt of the
    Registration Notice, irrevocably to agree to purchase all or any part of the
    Registrable Securities  proposed to  be so  sold for  cash at  a price  (the
    "OPTION  PRICE")  equal to  the  product of  (i)  the number  of Registrable
    Securities to  be so  purchased by  the Registrant  and (ii)  the then  Fair
    Market Value of such shares.
 
        (d)  Any purchase  of Registrable Securities  by the  Registrant (or its
    designee) under Section 11(c) shall  take place at a  closing to be held  at
    the  principal executive offices of the Registrant  or at the offices of its
    counsel at any reasonable date and time designated by the Registrant  and/or
    such  designee in such notice within  twenty business days after delivery of
    such notice, and any payment for the shares to be so purchased shall be made
    by delivery at the time of such closing in immediately available funds.
 
        (e) If the Registrant does not elect to exercise its option pursuant  to
    this Section 11 with respect to all Registrable Securities, it shall use its
    best  efforts to effect, as promptly  as practicable, the registration under
    the Securities Act of the unpurchased Registrable Securities proposed to  be
    so sold; PROVIDED, HOWEVER, that
 
           (i)  neither party shall be entitled to demand more than an aggregate
       of two effective registration statements hereunder, and
 
           (ii)  the  Registrant  will  not   be  required  to  file  any   such
       registration  statement during any period of  time (not to exceed 40 days
       after such request in the case of clause (A) below or 90 days in the case
       of clauses (B) and (C) below) when
 
               (A) the  Registrant  is  in  possession  of  material  non-public
           information  which it reasonably believes  would be detrimental to be
           disclosed at  such  time  and,  in the  opinion  of  counsel  to  the
           Registrant,  such information would be required  to be disclosed if a
           registration statement were filed at that time;
 
               (B) the  Registrant  is  required under  the  Securities  Act  to
           include   audited  financial  statements  for   any  period  in  such
           registration statement  and such  financial  statements are  not  yet
           available for inclusion in such registration statement; or
 
               (C)  the Registrant determines, in  its reasonable judgment, that
           such registration would interfere with any financing, acquisition  or
           other  material transaction  involving the  Registrant or  any of its
           affiliates.
 
        (f) The Registrant shall  use its reasonable best  efforts to cause  any
    Registrable  Securities  registered  pursuant  to  this  Section  11  to  be
    qualified  for  sale  under  the  securities  or  Blue  Sky  laws  of   such
    jurisdictions  as  the Designated  Holder may  reasonably request  and shall
    continue such registration or qualification in effect in such  jurisdiction;
    PROVIDED,  HOWEVER, that the Registrant shall  not be required to qualify to
    do  business  in,  or  consent  to  general  service  of  process  in,   any
    jurisdiction by reason of this provision.
 
                                      E-10
<PAGE>
        (g)  The registration rights set forth in this Section 11 are subject to
    the condition that the Designated  Holder shall provide the Registrant  with
    such  information with respect to  such holder's Registrable Securities, the
    plans for the distribution thereof, and such other information with  respect
    to such holder as, in the reasonable judgment of counsel for the Registrant,
    is  necessary  to  enable the  Registrant  to include  in  such registration
    statement all material  facts required  to be  disclosed with  respect to  a
    registration thereunder.
 
        (h)  A registration effected under this  Section 11 shall be effected at
    the Registrant's expense, except for underwriting discounts and  commissions
    and  the fees and the expenses of  counsel to the Designated Holder, and the
    Registrant shall provide to  the underwriters such documentation  (including
    certificates, opinions of counsel and "comfort" letters from auditors) as is
    customary   in  connection  with  underwritten   public  offerings  as  such
    underwriters may reasonably require.
 
        (i) In connection with any registration effected under this Section  11,
    the parties agree
 
           (i)  to indemnify  each other and  the underwriters  in the customary
       manner,
 
           (ii) to enter into  an underwriting agreement  in form and  substance
       customary  for transactions of  such type with the  Manager and the other
       underwriters participating in such offering, and
 
          (iii) to take all further actions which shall be reasonably  necessary
       to  effect such registration and sale  (including if the Manager deems it
       necessary, participating in road-show presentations).
 
        (j)   The Registrant  shall  be entitled  to  include (at  its  expense)
    additional shares of its common stock in a registration effected pursuant to
    this  Section 11 only if and to  the extent the Manager determines that such
    inclusion will  not  adversely affect  the  prospects for  success  of  such
    offering.
 
    12.   ADJUSTMENT UPON CHANGES IN  CAPITALIZATION.  Without limitation to any
restriction on  OPTION GRANTOR  contained in  this Agreement  or in  the  Merger
Agreement,  in the event of any change  in OPTION GRANTOR Common Stock by reason
of   stock   dividends,   splitups,    mergers   (other   than   the    Merger),
recapitalizations,  combinations, exchange of  shares or the  like, the type and
number of shares  or securities subject  to the OPTION  GRANTOR Option, and  the
purchase  price per share provided in Section 1, shall be adjusted appropriately
to restore  to  OPTION HOLDER  its  rights  hereunder, including  the  right  to
purchase from OPTION GRANTOR (or its successors) shares of OPTION GRANTOR Common
Stock (or such other shares or securities into which OPTION GRANTOR Common Stock
has  been so changed)  representing the Option Shares  Percentage of the Initial
Number of shares of OPTION GRANTOR Common Stock for the aggregate Exercise Price
calculated as of the date of this Agreement as provided in Section 1.
 
    13.   RESTRICTIVE LEGENDS.   Each  certificate representing  OPTION  GRANTOR
Shares  issued to  OPTION HOLDER  hereunder, and  OPTION HOLDER  Shares, if any,
delivered  to  OPTION  GRANTOR  at  a   Closing,  shall  include  a  legend   in
substantially the following form:
 
    THE  SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
    UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES OR
    BLUE SKY LAWS, AND MAY BE REOFFERED OR SOLD ONLY IF SO REGISTERED OR  IF
    AN  EXEMPTION FROM SUCH  REGISTRATION IS AVAILABLE.  SUCH SECURITIES ARE
    ALSO SUBJECT TO ADDITIONAL RESTRICTIONS ON TRANSFER AS SET FORTH IN  THE
    OPTION  HOLDER STOCK OPTION  AND TRIGGER PAYMENT  AGREEMENT, DATED AS OF
    NOVEMBER 10, 1995, A COPY OF WHICH MAY BE OBTAINED FROM THE ISSUER  UPON
    REQUEST.
 
It is understood and agreed that:
 
                                      E-11
<PAGE>
        (i)  the reference to the resale  restrictions of the Securities Act and
    state securities or Blue Sky  laws in the above  legend shall be removed  by
    delivery  of  substitute  certificate(s) without  such  reference  if OPTION
    HOLDER or OPTION GRANTOR, as  the case may be,  shall have delivered to  the
    other  party a copy of a letter from the  staff of the SEC, or an opinion of
    counsel, in  form and  substance satisfactory  to the  other party,  to  the
    effect  that such legend is not required  for purposes of the Securities Act
    or such laws;
 
        (ii) the reference  to the  provisions to  this Agreement  in the  above
    legend  shall be  removed by  delivery of  substitute certificate(s) without
    such reference if  the shares have  been sold or  transferred in  compliance
    with  the provisions of  this Agreement and under  circumstances that do not
    require the retention of such reference; and
 
       (iii) the legend shall  be removed in its  entirety if the conditions  in
    the preceding clauses (i) and (ii) are both satisfied.
 
In addition, such certificates shall bear any other legend as may be required by
law.  Certificates  representing shares  sold  in a  registered  public offering
pursuant to Section 11  shall not be  required to bear the  legend set forth  in
this Section 13.
 
    14.  BINDING EFFECT; NO ASSIGNMENT; NO THIRD PARTY BENEFICIARIES.
 
        (a) This Agreement shall be binding upon and inure to the benefit of the
    parties hereto and their respective successors and permitted assigns.
 
        (b)  Except as  expressly provided for  in this  Agreement, neither this
    Agreement  nor  the  rights  or  obligations  of  either  party  hereto  are
    assignable,  except by operation of law, or  with the written consent of the
    other party.
 
        (c) Nothing contained in this Agreement, express or implied, is intended
    to confer upon any person other than the parties hereto and their respective
    successors and  permitted  assigns any  rights  or remedies  of  any  nature
    whatsoever by reason of this Agreement.
 
        (d)  Any  Restricted  Shares sold  by  a  party in  compliance  with the
    provisions of Section 11 shall, upon  consummation of such sale, be free  of
    the  restrictions imposed  with respect  to such  shares by  this Agreement,
    unless and  until  such  party  shall repurchase  or  otherwise  become  the
    beneficial owner of such shares, and any transferee of such shares shall not
    be entitled to the registration rights of such party.
 
    15.   SPECIFIC PERFORMANCE.  The  parties hereto agree that irreparable harm
would occur in the event that any  of the provisions of this Agreement were  not
performed  in accordance with their specified  terms or were otherwise breached.
It is  accordingly  agreed that  the  parties hereto  shall  be entitled  to  an
injunction  or injunctions to prevent breaches  of this Agreement and to enforce
specifically the terms and provisions hereof  in any court of the United  States
or  any state having jurisdiction, this being in addition to any other remedy to
which they are entitled at law or equity.
 
    16.  VALIDITY.
 
        (a)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement  shall  not affect  the validity  or  enforceability of  the other
    provisions of this Agreement, which shall remain in full force and effect.
 
        (b) In  the event  any  court or  other  competent authority  holds  any
    provisions  of this Agreement to be null, void or unenforceable, the parties
    hereto shall  negotiate in  good  faith the  execution  and delivery  of  an
    amendment  to this Agreement in order, as nearly as possible, to effectuate,
    to the  extent permitted  by law,  the  intent of  the parties  hereto  with
    respect to such provision and the economic effects thereof.
 
        (c) Subject to Section 5, if for any reason any such court or regulatory
    agency  determines that OPTION HOLDER is not permitted to acquire, or OPTION
    GRANTOR is not permitted to
 
                                      E-12
<PAGE>
    repurchase pursuant  to Section  8,  the full  number  of shares  of  OPTION
    GRANTOR  Common  Stock provided  in Section  1  hereof (as  the same  may be
    adjusted), it is  the express intention  of OPTION GRANTOR  to allow  OPTION
    HOLDER  to acquire  or to require  OPTION GRANTOR to  repurchase such lesser
    number of shares as may be permissible without any amendment or modification
    hereof.
 
        (d) Each  party  agrees  that,  should  any  court  or  other  competent
    authority  hold any provision of  this Agreement or part  hereof to be null,
    void or unenforceable, or  order any party to  take any action  inconsistent
    herewith,  or not take any action required herein, the other party shall not
    be entitled to specific performance of  such provision or part hereof or  to
    any  other remedy,  including but not  limited to money  damages, for breach
    hereof or of any  other provision of  this Agreement or  part hereof as  the
    result of such holding or order.
 
    17.   NOTICES.  All  notices and other communications  hereunder shall be in
writing and shall be deemed given if (a) delivered personally, or (b) if sent by
overnight courier service (receipt confirmed in writing), or (c) if delivered by
facsimile transmission (with receipt  confirmed), or (d)  five days after  being
mailed by registered or certified mail (return receipt requested) to the parties
in each case to the following addresses (or at such other address for a party as
shall be specified by like notice):
 
    A.  If to OPTION HOLDER, to:
 
        Interstate Power Company
      1000 Main Street
      Dubuque, Iowa 52004-0789
 
       Attention: Wayne H. Stoppelmoor
                   Chairman
      Fax: (319) 557-2202
 
      with a copy to:
 
      Milbank, Tweed, Hadley & McCloy
       1 Chase Manhattan Plaza
       New York, New York 10005-1413
 
      Attention: John T. O'Connor, Esq.
       Fax: (212) 530-5219
 
    B.  If to OPTION GRANTOR, to:
 
        IES Industries Inc.
      IES Tower
      200 First Street, S.E.
      Cedar Rapids, Iowa 52401
 
        Attention: Lee Liu
      Fax: (319) 398-4204
 
        with a copy to:
 
        Winthrop, Stimson, Putnam & Roberts
      One Battery Park Plaza
      New York, New York 10004-1490
 
        Attention: Stephen R. Rusmisel, Esq.
      Fax: (212) 858-1500
 
                                      E-13
<PAGE>
    18.   GOVERNING LAW.   This Agreement shall be  governed by and construed in
accordance with the laws of the State of Delaware applicable to agreements  made
and  to be performed entirely within such State and without regard to its choice
of law principles or to any requirement as to jurisdiction or service of process
contained in Section 2708 of Title 6 of the Delaware Code.
 
    19.  INTERPRETATION.
 
        (a) When reference is  made in this Agreement  to Articles, Sections  or
    Exhibits,  such reference shall be to an Article, Section or Exhibit of this
    Agreement, as the case may be, unless otherwise indicated.
 
        (b) The table of contents and  headings contained in this Agreement  are
    for  reference  purposes and  shall not  affect  in any  way the  meaning or
    interpretation of the Agreement.
 
        (c) Whenever the words "include," "includes," or "including" are used in
    this Agreement, they shall  be deemed to be  followed by the words  "without
    limitation."
 
        (d) Whenever "or" is used in this Agreement it shall be construed in the
    nonexclusive sense.
 
    20.   COUNTERPARTS; EFFECT.   This Agreement may be  executed in one or more
counterparts, each of which shall be deemed to be an original, but all of  which
shall constitute one and the same agreement.
 
    21.   AMENDMENTS;  WAIVER.   This Agreement  may be  amended by  the parties
hereto and the terms and conditions hereof  may be waived only by an  instrument
in  writing signed on behalf of each of the parties hereto, or, in the case of a
waiver, by an instrument signed on behalf of the party waiving compliance.
 
    22.  EXTENSION OF TIME PERIODS.   The time periods for exercises of  certain
rights under Sections 2, 7 and 8 shall be extended (but in no event by more than
six months):
 
        (a)  to the extent necessary to  obtain all regulatory approvals for the
    exercise of such  rights, and for  the expiration of  all statutory  waiting
    periods; and
 
        (b)  to the extent necessary to  avoid any liability under Section 16(b)
    of the Exchange Act by reason of such exercise.
 
    IN WITNESS WHEREOF,  the parties  hereto have  caused this  Agreement to  be
executed by their respective duly authorized officers as of the date first above
written.
 
                                          IES INDUSTRIES INC.
 
                                          By: /s/ LEE LIU
 
                                             -----------------------------------
                                              Name: Lee Liu
                                              Title: Chairman of the Board,
                                                     President and Chief
                                                     Executive Officer
 
                                          INTERSTATE POWER COMPANY
 
                                          By: /s/ WAYNE H. STOPPELMOOR
 
                                             -----------------------------------
                                              Name: Wayne H. Stoppelmoor
                                              Title: Chairman of the Board,
                                                     President and Chief
                                                     Executive Officer
 
                                      E-14
<PAGE>
                                                                         ANNEX F
 
                   OPTION GRANTOR/OPTION HOLDER STOCK OPTION
                         AND TRIGGER PAYMENT AGREEMENT
 
    This STOCK OPTION AGREEMENT, dated as of November 10, 1995 (the "AGREEMENT")
by and among Interstate Power Company, a corporation organized under the laws of
the  State of  Delaware ("OPTION  GRANTOR" or  the "COMPANY")  and WPL Holdings,
Inc., a corporation organized under the laws of the State of Wisconsin  ("OPTION
HOLDER").
 
                         W I T N E S S E T H  T H A T:
 
    WHEREAS,  concurrently with  the execution  and delivery  of this Agreement,
OPTION GRANTOR,  OPTION HOLDER,  IES Industries  Inc., a  corporation  organized
under  the  laws  of  the  State  of  Iowa  ("IES"),  WPLH  Acquisition  Co.,  a
wholly-owned subsidiary of OPTION HOLDER organized  under the laws of the  State
of  Wisconsin  ("ACQUISITION"),  and Interstate  Power  Company,  a wholly-owned
subsidiary of OPTION GRANTOR organized under the laws of the State of Wisconsin,
are entering into  an Agreement and  Plan of  Merger, dated as  of November  10,
1995,  as amended (the "MERGER AGREEMENT"), which provides, INTER ALIA, upon the
terms and subject to the conditions thereof, for the merger of IES with and into
OPTION HOLDER in accordance with  the laws of the  States of Wisconsin and  Iowa
(the  "IES MERGER"), and the merger of  Acquisition with and into OPTION GRANTOR
(or a successor thereto) in accordance with  the laws of the States of  Delaware
and/or Wisconsin (the "INTERSTATE MERGER", and together with the IES Merger, the
"MERGER");
 
    WHEREAS,  in connection with  the execution of  the Merger Agreement, OPTION
GRANTOR, OPTION HOLDER and IES are entering into certain stock option agreements
dated as of the date hereof, of which this Agreement is one, whereby the parties
hereto grant each other an option with respect to certain shares of each other's
common stock on the terms and subject  to the conditions set forth therein  (the
"STOCK OPTION AGREEMENTS"); and
 
    WHEREAS,  as a  condition to OPTION  HOLDER's willingness to  enter into the
Merger Agreement, OPTION  HOLDER has  requested that OPTION  GRANTOR agree,  and
OPTION  GRANTOR has so agreed, to grant  to OPTION HOLDER an option with respect
to certain shares of OPTION GRANTOR's common stock, on the terms and subject  to
the conditions set forth herein;
 
    NOW,  THEREFORE, to induce OPTION HOLDER  to enter into the Merger Agreement
and certain  of  the  Stock  Option Agreements,  and  in  consideration  of  the
representations,  warranties, covenants and agreements  contained herein, in the
Merger Agreement and in the Stock Option Agreements to which OPTION GRANTOR  and
OPTION  HOLDER are parties,  the parties hereto, intending  to be legally bound,
hereby agree as follows:
 
    1.  GRANT OF OPTION.
 
        (a) Subject  to  the receipt  of  all regulatory  approvals  and  orders
    required  by OPTION GRANTOR as set forth in Section 6.4(c) of the Interstate
    Disclosure Schedule to  the Merger  Agreement and  by OPTION  HOLDER as  set
    forth  in  Section  4.4(c) of  the  WPL  Disclosure Schedule  to  the Merger
    Agreement, OPTION GRANTOR hereby grants OPTION HOLDER an irrevocable  option
    (the  "OPTION  GRANTOR OPTION")  to purchase  up to  that number  of shares,
    subject to  adjustment  as  provided  in Section  12  (the  "OPTION  GRANTOR
    SHARES"), of common stock, par value $3.50 per share, of OPTION GRANTOR (the
    "OPTION  GRANTOR COMMON  STOCK") equal to  a percentage  (the "OPTION SHARES
    PERCENTAGE"), which Option Shares Percentage is equal to the OPTION HOLDER's
    Participation Percentage as  defined below in  subsection (e), of  1,903,293
    shares  of OPTION GRANTOR Common Stock (being  19.9% of the number of shares
    of OPTION GRANTOR  Common Stock issued  and outstanding as  of November  10,
    1995 (the
 
                                      F-1
<PAGE>
    "INITIAL  NUMBER") in the manner set forth  below, at a price (the "EXERCISE
    PRICE") per OPTION  GRANTOR Share of  $28.9375 (which is  equal to the  Fair
    Market  Value (as defined below)  of an OPTION GRANTOR  Share as of the date
    hereof).
 
        (b) The Exercise Price shall be  payable, at OPTION HOLDER's option,  as
    follows:
 
           (i) in cash, or
 
           (ii)  subject to  the receipt  of all  approvals of  any Governmental
       Authority required for OPTION  GRANTOR to acquire,  and OPTION HOLDER  to
       issue, the OPTION HOLDER Shares (as defined below) from OPTION HOLDER, in
       shares  of common stock, $.01 par value, of OPTION HOLDER ("OPTION HOLDER
       SHARES"),
 
    in either case in accordance with Section 4 hereof.
 
        (c) Notwithstanding  the foregoing,  in  no event  shall the  number  of
    OPTION  GRANTOR Shares  for which the  OPTION GRANTOR  Option is exercisable
    exceed the product of the Option  Shares Percentage and the Initial  Number,
    subject to adjustment as provided in Section 12.
 
        (d)  As used herein, the  "FAIR MARKET VALUE" of  any share shall be the
    average of the  daily closing sales  price for  such share on  the New  York
    Stock  Exchange (the "NYSE") during  the ten NYSE trading  days prior to the
    fifth NYSE trading day preceding  the date such Fair  Market Value is to  be
    determined.
 
        (e)  For purposes of this  Agreement the term "PARTICIPATION PERCENTAGE"
    shall have  the  same  meaning  as  in  Section  10.3(f)(i)  of  the  Merger
    Agreement,  except that  the numerator  and denominator  shall be calculated
    based on the number of  shares of WPL Common  Stock which would be  issuable
    (or,  in the case of  WPL, retained by its  shareholders) on a fully diluted
    basis had the Effective Time occurred as  of the date on which the  Exercise
    Notice  is delivered under Section 2 hereof  or the date on which demand for
    the Trigger Payment (as defined herein) is given under Section 5 hereof,  as
    the  case may be. Other capitalized terms used herein but not defined herein
    shall have the meanings set forth in the Merger Agreement.
 
    2.  EXERCISE OF OPTION.
 
        (a) The OPTION  GRANTOR Option  may be  exercised by  OPTION HOLDER,  in
    whole  or  in part,  at  any time  or  from time  to  time after  the Merger
    Agreement becomes  terminable by  OPTION  HOLDER under  circumstances  which
    could  entitle OPTION HOLDER  to a termination fee  under Section 10.3(a) of
    the  Merger  Agreement  (provided  that  the  events  specified  in  Section
    10.3(a)(ii)(A)  of the  Merger Agreement  shall have  occurred, although the
    events specified in Section 10.3(a)(ii)(B) thereof need not have  occurred),
    or Section 10.3(b) of the Merger Agreement (regardless of whether the Merger
    Agreement  is actually terminated  or whether there occurs  a closing of any
    Business Combination involving a Target Party or a closing by which a Target
    Party becomes a Subsidiary),  any such event by  which the Merger  Agreement
    becomes  so  terminable  by OPTION  HOLDER  being  referred to  herein  as a
    "TRIGGER EVENT").
 
         (b)(i) OPTION GRANTOR shall notify OPTION HOLDER promptly in writing of
       the occurrence of any Trigger Event, it being understood that the  giving
       of such notice by OPTION GRANTOR shall not be a condition to the right of
       OPTION HOLDER to exercise the OPTION GRANTOR Option.
 
           (ii) In the event OPTION HOLDER wishes to exercise the OPTION GRANTOR
       Option,  OPTION HOLDER shall deliver to OPTION GRANTOR written notice (an
       "EXERCISE NOTICE") specifying the total  number of OPTION GRANTOR  Shares
       it wishes to purchase.
 
          (iii)  Upon  the giving  by  OPTION HOLDER  to  OPTION GRANTOR  of the
       Exercise Notice  and  the tender  of  the applicable  aggregate  Exercise
       Price, OPTION HOLDER, to the extent permitted by law and OPTION GRANTOR's
       organizational  documents,  and provided  that  the conditions  to OPTION
       GRANTOR's obligation to issue the OPTION GRANTOR
 
                                      F-2
<PAGE>
       Shares to  OPTION HOLDER  hereunder  set forth  in  Section 3  have  been
       satisfied  or waived, shall be  deemed to be the  holder of record of the
       OPTION GRANTOR Shares issuable  upon such exercise, notwithstanding  that
       the  stock transfer books of OPTION GRANTOR  shall then be closed or that
       certificates representing such  OPTION GRANTOR Shares  shall not then  be
       actually delivered to OPTION HOLDER.
 
          (iv) Each closing of a purchase of OPTION GRANTOR Shares (a "CLOSING")
       shall  occur at a  place, on a date,  and at a  time designated by OPTION
       HOLDER in an Exercise Notice delivered  at least two business days  prior
       to the date of the Closing.
 
        (c) The OPTION GRANTOR Option shall terminate upon the earliest to occur
    of:
 
           (i) the Effective Time of the Merger;
 
           (ii) the termination of the Merger Agreement pursuant to Section 10.1
       thereof,  other than under circumstances  which also constitute a Trigger
       Event under this Agreement;
 
          (iii) 180 days following any termination of the Merger Agreement  upon
       or during the continuance of a Trigger Event (or if, at the expiration of
       such  180 day  period, the OPTION  GRANTOR Option cannot  be exercised by
       reason of any applicable judgment, decree, order, law or regulation,  ten
       business  days after such impediment to  exercise shall have been removed
       or shall have become  final and not  subject to appeal,  but in no  event
       under this clause (iii) later than May 10, 1998); and
 
          (iv)  payment by  OPTION GRANTOR of  the Trigger Payment  set forth in
       Section 5 of this Agreement to OPTION HOLDER.
 
        (d) Notwithstanding the foregoing, the OPTION GRANTOR Option may not  be
    exercised  if  (i)  OPTION  HOLDER  is in  material  breach  of  any  of its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in  this Agreement or in  the Merger Agreement,  or
    (ii) a Trigger Payment has been paid pursuant to Section 5 of this Agreement
    or demand therefor has been made and not withdrawn.
 
    3.   CONDITIONS TO CLOSING.   The obligation of  OPTION GRANTOR to issue the
OPTION GRANTOR Shares to  OPTION HOLDER hereunder is  subject to the  conditions
that
 
        (a)  all waiting periods,  if any, under  the HSR Act  applicable to the
    issuance and acquisition of the  OPTION GRANTOR Shares hereunder shall  have
    expired or have been terminated;
 
        (b)  the OPTION GRANTOR  Shares, and any OPTION  HOLDER Shares which are
    issued in  payment of  the  Exercise Price,  shall  have been  approved  for
    listing on the NYSE subject only to official notice of issuance;
 
        (c)   all  consents,   approvals,  orders   or  authorizations   of,  or
    registrations, declarations or  filings with,  any federal,  state or  local
    administrative  agency  or  commission  or  other  federal,  state  or local
    Governmental Authority, if any, required in connection with the issuance  by
    OPTION  GRANTOR and the  acquisition by OPTION HOLDER  of the OPTION GRANTOR
    Shares hereunder  shall  have  been obtained  or  made,  including,  without
    limitation,  the approval of the  SEC under Sections 9  and 10 of the Public
    Utility Holding  Company Act  of  1935, as  amended  (the "1935  ACT"),  the
    approval  of  the Iowa  Utilities Board,  the  Public Service  Commission of
    Minnesota and the Illinois Commerce Commission of the issuance of the OPTION
    GRANTOR Shares  by OPTION  GRANTOR and,  if applicable,  the acquisition  of
    OPTION  GRANTOR  Shares by  OPTION HOLDER,  and the  approval of  the Public
    Service Commission of  Wisconsin of  the acquisition of  the OPTION  GRANTOR
    Shares  by  OPTION  HOLDER and,  if  applicable, the  acquisition  by OPTION
    GRANTOR  of  the  OPTION  HOLDER  Shares  constituting  the  Exercise  Price
    hereunder; and
 
                                      F-3
<PAGE>
        (d)  no preliminary or permanent injunction  or other order by any court
    of competent jurisdiction prohibiting or otherwise restraining such issuance
    shall be in effect.
 
The condition set forth in paragraph (b) above may be waived by OPTION  GRANTOR,
in the case of OPTION HOLDER Shares, and by OPTION HOLDER, in the case of OPTION
GRANTOR Shares, in the sole discretion of the waiving party.
 
    4.  CLOSING.  At any Closing,
 
        (a)  OPTION GRANTOR  shall deliver  to OPTION  HOLDER or  its designee a
    single certificate  in definitive  form representing  the number  of  OPTION
    GRANTOR  Shares designated  by OPTION  HOLDER in  its Exercise  Notice, such
    certificate to be registered in  the name of OPTION  HOLDER and to bear  the
    legend set forth in Section 13; and
 
        (b)  OPTION HOLDER shall  deliver to OPTION  GRANTOR the aggregate price
    for the OPTION GRANTOR Shares so designated and being purchased by
 
           (i) wire transfer of immediately  available funds or certified  check
       or bank check, or
 
           (ii)  subject to  the condition  in Section  1(b)(ii), delivery  of a
       certificate or  certificates representing  the  number of  OPTION  HOLDER
       Shares being issued by OPTION HOLDER in consideration thereof, determined
       in accordance with Section 4(c).
 
        (c)  In  the event  that OPTION  HOLDER issues  OPTION HOLDER  Shares to
    OPTION GRANTOR in consideration of OPTION GRANTOR Shares pursuant to Section
    4(b)(ii), the number of OPTION HOLDER Shares to be so issued shall be  equal
    to the quotient obtained by dividing:
 
           (i)  the  product of  (x) the  number of  OPTION GRANTOR  Shares with
       respect to which the OPTION GRANTOR Option is being exercised and (y) the
       Exercise Price, by
 
           (ii) the Fair Market Value of the OPTION HOLDER Shares as of the date
       immediately preceding the date the Exercise Notice is delivered to OPTION
       GRANTOR.
 
        (d) OPTION GRANTOR  shall pay  all expenses,  and any  and all  Federal,
    state  and local taxes and  other charges that may  be payable in connection
    with the preparation, issue  and delivery of  stock certificates under  this
    Section 4.
 
    5.  TRIGGER PAYMENT.
 
        (a)   TRIGGER PAYMENT.  Subject to  the provisions of Section 10.3(e) of
    the Merger  Agreement,  if a  Trigger  Event  shall have  occurred  and  any
    regulatory approval or order required for the issuance by OPTION GRANTOR, or
    the  acquisition by OPTION HOLDER, of  the OPTION GRANTOR Option pursuant to
    Section 1 hereof shall not have been obtained, OPTION HOLDER shall have  the
    right  to receive, and OPTION GRANTOR shall  pay to OPTION HOLDER, an amount
    (the "TRIGGER PAYMENT") equal to the product of
 
           (i) the maximum number of OPTION GRANTOR Shares that would have  been
       subject  to purchase by OPTION HOLDER upon exercise of the OPTION GRANTOR
       Option pursuant  to  Sections 1  and  2  hereof if  all  such  regulatory
       approvals or orders had been obtained, and
 
           (ii)  the difference between  (A) the Market/Offer  Price (as defined
       herein), determined as  of the  date on which  notice of  demand for  the
       Trigger  Payment is  given by OPTION  HOLDER, and (B)  the Exercise Price
       (but only if such Market/Offer Price is higher than such Exercise Price).
 
    Demand for the Trigger Payment shall  be given by notice in accordance  with
    the  provisions of Section 17  hereof. The Trigger Payment  shall be paid to
    OPTION HOLDER by OPTION
 
                                      F-4
<PAGE>
    GRANTOR on  the  Payment Date  (as  defined  herein), by  wire  transfer  of
    immediately  available funds  to an account  to be designated  in writing by
    OPTION HOLDER not less than two business days before the Payment Date.
 
        (b)  PAYMENT DATE.  For purposes of this Section 5, "PAYMENT DATE" means
    the date on which termination fees are required to be paid by OPTION GRANTOR
    to OPTION HOLDER under Section  10.3(a) or 10.3(b), as  the case may be,  of
    the  Merger Agreement  as a  result of the  occurrence of  the Trigger Event
    referred to in subsection (a) of this Section 5.
 
        (c)  CERTAIN CONDITIONS.  OPTION GRANTOR shall have no obligation to pay
    the Trigger Payment if  OPTION HOLDER is  in material breach  of any of  its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in this Agreement or in the Merger Agreement.
 
    6.    REPRESENTATIONS  AND WARRANTIES  OF  OPTION GRANTOR.    OPTION GRANTOR
represents and warrants to OPTION HOLDER that
 
        (a) except as set forth in  Section 6.4(a) of the Interstate  Disclosure
    Schedule to the Merger Agreement, OPTION GRANTOR has the corporate power and
    authority  to enter  into this  Agreement and  to carry  out its obligations
    hereunder, subject  in the  case of  the repurchase  of the  OPTION  GRANTOR
    Shares  pursuant to  Section 8(a)  to applicable  law and  the provisions of
    OPTION GRANTOR's Articles of Incorporation, as amended (the "OPTION  GRANTOR
    ARTICLES");
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION GRANTOR, and, assuming the due authorization, execution and  delivery
    hereof  by  OPTION  HOLDER  and  the  receipt  of  all  required  regulatory
    approvals, constitutes a  valid and  binding obligation  of OPTION  GRANTOR,
    enforceable  against OPTION GRANTOR in accordance  with its terms, except as
    may be limited by applicable bankruptcy, insolvency, reorganization or other
    similar laws affecting the enforcement  of creditors' rights generally,  and
    except  that  the  availability of  equitable  remedies,  including specific
    performance, may be subject to the discretion of any court before which  any
    proceeding therefor may be brought;
 
        (c) OPTION GRANTOR has taken all necessary corporate action to authorize
    and  reserve for issuance  and to permit  it to issue,  upon exercise of the
    OPTION GRANTOR Option,  and at all  times from the  date hereof through  the
    expiration  of the  OPTION GRANTOR  Option will  have reserved,  the Initial
    Number of authorized and unissued  OPTION GRANTOR Shares, such amount  being
    subject  to adjustment as provided  in Section 12, all  of which, upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d) upon delivery of the OPTION GRANTOR Shares to OPTION HOLDER upon the
    exercise of the OPTION GRANTOR Option, OPTION HOLDER will acquire the OPTION
    GRANTOR  Shares free and  clear of all  claims, liens, charges, encumbrances
    and security interests of any nature whatsoever;
 
        (e) except as described in  Section 6.4(b) of the Interstate  Disclosure
    Schedule  to  the  Merger  Agreement, the  execution  and  delivery  of this
    Agreement by  OPTION  GRANTOR does  not,  and, subject  to  compliance  with
    applicable  law  and  the  OPTION  GRANTOR  Articles  with  respect  to  the
    repurchase of  the  OPTION GRANTOR  Shares  pursuant to  Section  8(a),  the
    consummation  by OPTION GRANTOR of the transactions contemplated hereby will
    not violate, conflict with, or  result in a breach  of any provision of,  or
    constitute  a default (with or  without notice or a  lapse of time, or both)
    under, or  result  in the  termination  of, or  accelerate  the  performance
    required  by,  or  result  in  a  right  of  termination,  cancellation,  or
    acceleration of any obligation or the  loss of a material benefit under,  or
    the  creation of a  lien, pledge, security interest  or other encumbrance on
 
                                      F-5
<PAGE>
    assets  (any  such  conflict,  violation,  default,  right  of  termination,
    cancellation,  acceleration, loss or creation, hereinafter a "VIOLATION") of
    OPTION GRANTOR or any of its Subsidiaries, pursuant to
 
           (i) any provision  of the OPTION  GRANTOR Articles or  the Bylaws  of
       OPTION GRANTOR,
 
           (ii)  any provisions of any material  loan or credit agreement, note,
       mortgage, indenture, lease, benefit plan or other agreement,  obligation,
       instrument,   permit,  concession,  franchise  or  license  (any  of  the
       foregoing in effect on the date  hereof being referred to as a  "MATERIAL
       CONTRACT")  of OPTION GRANTOR or its subsidiaries or to which any of them
       is a party, or
 
          (iii) any judgment,  order, decree, statute,  law, ordinance, rule  or
       regulation  applicable  to OPTION  GRANTOR or  its properties  or assets,
       which Violation,  in the  case  of each  clauses  (ii) and  (iii),  could
       reasonably  be expected to have an OPTION GRANTOR Material Adverse Effect
       (except that  no  representation  or warranty  is  given  concerning  any
       Violation of a Material Contract with respect to the repurchase of OPTION
       GRANTOR Shares pursuant to Section 8(a));
 
        (f)  except as described in Section  6.4(c) of the Interstate Disclosure
    Schedule to the Merger Agreement or Section 1 or 3 hereof, the execution and
    delivery of this Agreement by OPTION  GRANTOR does not, and the  performance
    of this Agreement by OPTION GRANTOR will not, require any consent, approval,
    authorization or permit of, filing with or notification to, any Governmental
    Authority;
 
        (g)  none of OPTION GRANTOR,  any of its affiliates  or anyone acting on
    its or their  behalf, has  issued, sold or  offered any  security of  OPTION
    GRANTOR  to any person under circumstances that would cause the issuance and
    sale of OPTION  GRANTOR Shares,  as contemplated  by this  Agreement, to  be
    subject  to the registration requirements of the Securities Act as in effect
    on the  date hereof,  and, assuming  the representations  and warranties  of
    OPTION  HOLDER contained in Section 7(g) are true and correct, the issuance,
    sale and delivery  of the OPTION  GRANTOR Shares hereunder  would be  exempt
    from the registration and prospectus delivery requirements of the Securities
    Act,  as in effect on the date hereof (and OPTION GRANTOR shall not take any
    action which would cause the issuance, sale, and delivery of OPTION  GRANTOR
    Shares hereunder not to be exempt from such requirements); and
 
        (h) any OPTION HOLDER Shares acquired pursuant to this Agreement will be
    acquired for OPTION GRANTOR's own account, for investment purposes only, and
    will  not  be  acquired  by  OPTION  GRANTOR  with  a  view  to  the  public
    distribution thereof  in  violation  of  any  applicable  provision  of  the
    Securities Act.
 
    7.    REPRESENTATIONS  AND  WARRANTIES  OF  OPTION  HOLDER.    OPTION HOLDER
represents and warrants to OPTION GRANTOR that
 
        (a) except  as  set forth  in  Schedule  4.4(a) of  the  WPL  Disclosure
    Schedule  to the Merger Agreement, OPTION HOLDER has the corporate power and
    authority to enter  into this  Agreement and  to carry  out its  obligations
    hereunder;
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION HOLDER and,  assuming the due  authorization, execution and  delivery
    hereof  by  OPTION  GRANTOR  and  the  receipt  of  all  required regulatory
    approvals, constitutes  a valid  and binding  obligation of  OPTION  HOLDER,
    enforceable  against OPTION HOLDER in  accordance with its respective terms,
    except  as   may   be   limited  by   applicable   bankruptcy,   insolvency,
    reorganization,   or  other  similar  laws   affecting  the  enforcement  of
    creditors' rights generally, and except  that the availability of  equitable
    remedies,  including specific performance, may  be subject to the discretion
    of any court before which any proceeding may be brought;
 
                                      F-6
<PAGE>
        (c) prior to any  delivery of OPTION HOLDER  Shares in consideration  of
    the  purchase of OPTION  GRANTOR Shares pursuant  hereto, OPTION HOLDER will
    have taken all necessary corporate action  to authorize for issuance and  to
    permit  it to  issue such  OPTION HOLDER  Shares, all  of which,  upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be  duly authorized, validly issued, fully paid and nonassessable (except as
    otherwise provided in Section 180.0622(2)(b) of the WBCL);
 
        (d) upon any delivery of such OPTION HOLDER Shares to OPTION GRANTOR  in
    consideration  of  the purchase  of OPTION  GRANTOR Shares  pursuant hereto,
    OPTION GRANTOR will acquire the OPTION  HOLDER Shares free and clear of  all
    claims,  liens, charges, encumbrances  and security interests  of any nature
    whatsoever;
 
        (e) except as described in Section 4.4(b) of the WPL Disclosure Schedule
    to the Merger  Agreement, the execution  and delivery of  this Agreement  by
    OPTION  HOLDER  does  not, and  the  consummation  by OPTION  HOLDER  of the
    transactions contemplated hereby will not, violate, conflict with, or result
    in the breach of any provision of, or constitute a default (with or  without
    notice  or a lapse  of time, or both)  under, or result  in any Violation by
    OPTION HOLDER or any of its Subsidiaries, pursuant to
 
           (i) any  provision of  the  Articles of  Incorporation or  Bylaws  of
       OPTION HOLDER,
 
           (ii)   any  Material  Contract  of  OPTION   HOLDER  or  any  of  its
       subsidiaries or to which any of them is a party, or
 
          (iii) any judgment,  order, decree, statute,  law, ordinance, rule  or
       regulation applicable to OPTION HOLDER or its properties or assets,
 
    which Violation, in the case of each of clauses (ii) or (iii), would have an
    OPTION HOLDER Material Adverse Effect;
 
        (f) except as described in Section 4.4(c) of the WPL Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of  this Agreement by OPTION HOLDER does not, and the consummation by OPTION
    HOLDER of  the  transactions  contemplated  hereby  will  not,  require  any
    consent,  approval, authorization or permit  of, filing with or notification
    to, any Governmental Authority; and
 
        (g) any  OPTION GRANTOR  Shares  acquired upon  exercise of  the  OPTION
    GRANTOR  Option  will  be  acquired for  OPTION  HOLDER's  own  account, for
    investment purposes only and will not  be, and the OPTION GRANTOR Option  is
    not  being, acquired by OPTION HOLDER with a view to the public distribution
    thereof, in violation of any applicable provision of the Securities Act.
 
    8.  CERTAIN REPURCHASES.
 
        (a)  OPTION HOLDER "PUT".   At the request  of OPTION HOLDER by  written
    notice (x) at any time during which the OPTION GRANTOR Option is exercisable
    pursuant  to Section  2 (the  "REPURCHASE PERIOD"),  OPTION GRANTOR  (or any
    successor entity thereof) shall, if permitted by applicable law, the  OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase from  OPTION HOLDER  all or  any portion  of the  OPTION  GRANTOR
    Option,  at the price  set forth in  subparagraph (i) below,  or, (y) at any
    time prior to May 10, 1997 (provided that such date shall be extended to May
    10, 1998 under the circumstances where the date after which either party may
    terminate the Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger
    Agreement  has  been  extended to  May  10,  1998), OPTION  GRANTOR  (or any
    successor entity thereof) shall, if permitted by applicable law, the  OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase from  OPTION HOLDER  all or  any portion  of the  OPTION  GRANTOR
    Shares  purchased by OPTION HOLDER pursuant to the OPTION GRANTOR Option, at
    the price set forth in subparagraph (ii) below:
 
                                      F-7
<PAGE>
         (i)(A) The  difference between  the  "MARKET/OFFER PRICE"  (as  defined
       below)  for shares of OPTION  GRANTOR Common Stock as  of the date OPTION
       HOLDER gives  notice of  its intent  to exercise  its rights  under  this
       Section  8 and  the Exercise  Price, multiplied  by the  number of OPTION
       GRANTOR Shares  purchasable pursuant  to the  OPTION GRANTOR  Option  (or
       portion  thereof with  respect to which  OPTION HOLDER  is exercising its
       rights under  this Section  8), but  only if  the Market/Offer  Price  is
       greater than the Exercise Price.
 
           (B)  For purposes of this Agreement, "MARKET/OFFER PRICE" shall mean,
       as of any date, the higher of (I) the price per share offered as of  such
       date pursuant to any tender or exchange offer or other offer with respect
       to  a Business Combination  involving OPTION GRANTOR  as the Target Party
       which was made prior to such date  and not terminated or withdrawn as  of
       such  date and (II) the Fair Market  Value of OPTION GRANTOR Common Stock
       as of such date.
 
        (ii)(A) The product of  (I) the sum  of (a) the  Exercise Price paid  by
       OPTION  HOLDER per OPTION  GRANTOR Share acquired  pursuant to the OPTION
       GRANTOR Option,  and (b)  the difference  between the  "Offer Price"  (as
       defined  below) and the  Exercise Price, but  only if the  Offer Price is
       greater than the Exercise  Price, and (II) the  number of OPTION  GRANTOR
       Shares so to be repurchased pursuant to this Section 8.
 
           (B)  For purposes of this clause (ii), the "OFFER PRICE" shall be the
       highest price per share offered pursuant to a tender or exchange offer or
       other Business Combination offer involving  OPTION GRANTOR as the  Target
       Party during the Repurchase Period prior to the delivery by OPTION HOLDER
       of a notice of repurchase.
 
        (b)   REDELIVERY OF OPTION  HOLDER SHARES.  If  OPTION HOLDER shall have
    previously elected  to  purchase  OPTION  GRANTOR  Shares  pursuant  to  the
    exercise of the OPTION GRANTOR Option by the issuance and delivery of OPTION
    HOLDER  Shares, then OPTION GRANTOR shall, if so requested by OPTION HOLDER,
    in fulfillment of its obligation pursuant to Section 8(a)(y) (that is,  with
    respect  to the Exercise Price only and without limitation to its obligation
    to pay additional consideration under clause (b) of Section 8(a)(ii)(A)(I)),
    redeliver the certificates for such  OPTION HOLDER Shares to OPTION  HOLDER,
    free and clear of all liens, claims, charges and encumbrances of any kind or
    nature  whatsoever; PROVIDED, HOWEVER, that if at  any time less than all of
    the OPTION GRANTOR  Shares so  purchased by  OPTION HOLDER  pursuant to  the
    OPTION  GRANTOR Option are  to be repurchased by  OPTION GRANTOR pursuant to
    Section 8(a)(y), then (i) OPTION GRANTOR shall be obligated to redeliver  to
    OPTION HOLDER the same proportion of such OPTION HOLDER Shares as the number
    of OPTION GRANTOR Shares that OPTION GRANTOR is then obligated to repurchase
    bears  to the number of OPTION GRANTOR Shares acquired by OPTION HOLDER upon
    exercise of the OPTION GRANTOR Option and (ii) OPTION HOLDER shall issue  to
    OPTION  GRANTOR  new certificates  representing  those OPTION  HOLDER Shares
    which are  not due  to be  redelivered  to OPTION  HOLDER pursuant  to  this
    Section  8(b) to the extent that excess OPTION HOLDER Shares are included in
    the certificates redelivered to OPTION HOLDER by OPTION GRANTOR.
 
        (c)  PAYMENT AND REDELIVERY OF OPTION GRANTOR OPTIONS OR SHARES. In  the
    event  OPTION  HOLDER  exercises its  rights  under this  Section  8, OPTION
    GRANTOR shall, within ten business days thereafter, pay the required  amount
    to  OPTION HOLDER  in immediately  available funds  and OPTION  HOLDER shall
    surrender to OPTION GRANTOR the OPTION GRANTOR Option or the certificate  or
    certificates evidencing the OPTION GRANTOR Shares purchased by OPTION HOLDER
    pursuant  hereto, and  OPTION HOLDER shall  warrant that it  owns the OPTION
    GRANTOR Option or  such shares and  that the OPTION  GRANTOR Option or  such
    shares  are then free and  clear of all liens,  claims, damages, charges and
    encumbrances of any kind or nature whatsoever.
 
                                      F-8
<PAGE>
        (d)  OPTION  HOLDER "CALL".   If OPTION HOLDER  has elected to  purchase
    OPTION  GRANTOR Shares pursuant to the exercise of the OPTION GRANTOR Option
    by the issuance and delivery  of OPTION HOLDER Shares, notwithstanding  that
    OPTION  HOLDER may  no longer  hold any such  OPTION GRANTOR  Shares or that
    OPTION HOLDER elects not to exercise its other rights under this Section  8,
    OPTION HOLDER may require, at any time or from time to time prior to May 10,
    1997  (provided that such date  shall be extended to  May 10, 1998 under the
    circumstances where  the date  after which  either party  may terminate  the
    Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger Agreement has
    been extended to May 10, 1998), OPTION GRANTOR to sell to OPTION HOLDER  any
    such  OPTION HOLDER  Shares at  the price  attributed to  such OPTION HOLDER
    Shares pursuant to Section 4 plus interest at the rate of 8.75% per annum on
    such amount from the  Closing Date relating to  the exchange of such  OPTION
    HOLDER  Shares pursuant to Section 4 to  the Closing Date under this Section
    8(d) less any dividends on such OPTION HOLDER Shares paid during such period
    or declared and  payable to  stockholders of record  on a  date during  such
    period.
 
        (e)   REPURCHASE PRICE REDUCED AT OPTION  HOLDER'S OPTION.  In the event
    the repurchase price specified in Section 8(a) would subject the purchase of
    the OPTION GRANTOR Option or the  OPTION GRANTOR Shares purchased by  OPTION
    HOLDER  pursuant to the OPTION GRANTOR Option  to a vote of the shareholders
    of OPTION GRANTOR pursuant to applicable law or the OPTION GRANTOR Articles,
    then OPTION HOLDER may, at its  election, reduce the repurchase price to  an
    amount  which would permit such repurchase  without the necessity for such a
    shareholder vote.
 
    9.  VOTING  OF SHARES.   Following the date  hereof and prior  to the  fifth
anniversary  of the date  hereof (the "EXPIRATION DATE"),  each party shall vote
any shares of capital stock of the  other party acquired by such party  pursuant
to  this  Agreement ("RESTRICTED  SHARES"), including  any OPTION  HOLDER Shares
issued pursuant to  Section 1(b),  or otherwise beneficially  owned (within  the
meaning  of Rule 13d-3 promulgated under the Securities Exchange Act of 1934, as
amended (the "EXCHANGE ACT")), by such party on each matter submitted to a  vote
of  shareholders of  such other party  for and  against such matter  in the same
proportion as the vote of all other  shareholders of such other party are  voted
(whether by proxy or otherwise) for and against such matter.
 
    10.  RESTRICTIONS ON TRANSFER.
 
        (a)   RESTRICTIONS ON  TRANSFER.  Prior to  the Expiration Date, neither
    party shall, directly or indirectly, by operation of law or otherwise, sell,
    assign, pledge, or otherwise  dispose of or  transfer any Restricted  Shares
    beneficially  owned by such party, other than  (i) pursuant to Section 8, or
    (ii) in accordance with Section 10(b) or Section 11.
 
        (b)    PERMITTED  SALES.    Following  the  termination  of  the  Merger
    Agreement,  a  party  shall  be  permitted  to  sell  any  Restricted Shares
    beneficially owned  by it  if such  sale is  made pursuant  to a  tender  or
    exchange   offer  that  has  been  approved  or  recommended,  or  otherwise
    determined to be fair to  and in the best  interests of the shareholders  of
    the  other party, by a majority of the  members of the Board of Directors of
    such other party, which majority shall  include a majority of directors  who
    were directors prior to the announcement of such tender or exchange offer.
 
                                      F-9
<PAGE>
    11.  REGISTRATION RIGHTS.
 
        (a)  Following  the termination  of the  Merger Agreement,  either party
    hereto that owns Restricted  Shares (a "DESIGNATED  HOLDER") may by  written
    notice  (the "REGISTRATION  NOTICE") to  the other  party (the "REGISTRANT")
    request the Registrant to register under the Securities Act all or any  part
    of  the Restricted Shares beneficially owned  by such Designated Holder (the
    "REGISTRABLE  SECURITIES")  pursuant   to  a  bona   fide  firm   commitment
    underwritten  public  offering,  in  which  the  Designated  Holder  and the
    underwriters shall  effect  as  wide  a  distribution  of  such  Registrable
    Securities  as is reasonably practicable and shall use their best efforts to
    prevent any person  (including any Group  (as used in  Rule 13d-5 under  the
    Exchange  Act))  and its  affiliates from  purchasing through  such offering
    Restricted Shares representing  more than  1% of the  outstanding shares  of
    common  stock  of the  Registrant  on a  fully  diluted basis  (a "PERMITTED
    OFFERING").
 
        (b) The Registration Notice shall include a certificate executed by  the
    Designated  Holder and its proposed  managing underwriter, which underwriter
    shall be an investment banking  firm of nationally recognized standing  (the
    "MANAGER"), stating that
 
           (i) they have a good faith intention to commence promptly a Permitted
       Offering, and
 
           (ii)   the  manager  in  good  faith  believes  that,  based  on  the
       then-prevailing  market  conditions,  it  will   be  able  to  sell   the
       Registrable  Securities at a per share price equal to at least 80% of the
       then Fair Market Value of such shares.
 
        (c) The  Registrant (and/or  any person  designated by  the  Registrant)
    shall  thereupon have the option exercisable  by written notice delivered to
    the Designated Holder  within ten  business days  after the  receipt of  the
    Registration Notice, irrevocably to agree to purchase all or any part of the
    Registrable  Securities proposed  to be  so sold  for cash  at a  price (the
    "OPTION PRICE")  equal to  the  product of  (i)  the number  of  Registrable
    Securities  to be  so purchased  by the  Registrant and  (ii) the  then Fair
    Market Value of such shares.
 
        (d) Any purchase  of Registrable  Securities by the  Registrant (or  its
    designee)  under Section 11(c) shall  take place at a  closing to be held at
    the principal executive offices of the  Registrant or at the offices of  its
    counsel  at any reasonable date and time designated by the Registrant and/or
    such designee in such notice within  twenty business days after delivery  of
    such notice, and any payment for the shares to be so purchased shall be made
    by delivery at the time of such closing in immediately available funds.
 
        (e)  If the Registrant does not elect to exercise its option pursuant to
    this Section 11 with respect to all Registrable Securities, it shall use its
    best efforts to effect, as  promptly as practicable, the registration  under
    the  Securities Act of the unpurchased Registrable Securities proposed to be
    so sold; PROVIDED, HOWEVER, that
 
           (i) neither party shall be entitled to demand more than an  aggregate
       of two effective registration statements hereunder, and
 
           (ii)   the  Registrant  will  not  be   required  to  file  any  such
       registration statement during any period of  time (not to exceed 40  days
       after such request in the case of clause (A) below or 90 days in the case
       of clauses (B) and (C) below) when
 
               (A)  the  Registrant  is  in  possession  of  material non-public
           information which it reasonably believes  would be detrimental to  be
           disclosed  at  such  time  and,  in the  opinion  of  counsel  to the
           Registrant, such information would be  required to be disclosed if  a
           registration statement were filed at that time;
 
               (B)  the  Registrant  is  required under  the  Securities  Act to
           include  audited  financial  statements   for  any  period  in   such
           registration  statement  and such  financial  statements are  not yet
           available for inclusion in such registration statement; or
 
                                      F-10
<PAGE>
               (C) the Registrant determines,  in its reasonable judgment,  that
           such  registration would interfere with any financing, acquisition or
           other material transaction  involving the  Registrant or  any of  its
           affiliates.
 
        (f)  The Registrant shall  use its reasonable best  efforts to cause any
    Registrable  Securities  registered  pursuant  to  this  Section  11  to  be
    qualified   for  sale  under  the  securities  or  Blue  Sky  laws  of  such
    jurisdictions as  the Designated  Holder may  reasonably request  and  shall
    continue  such registration or qualification in effect in such jurisdiction;
    PROVIDED, HOWEVER, that the Registrant shall  not be required to qualify  to
    do   business  in,  or  consent  to  general  service  of  process  in,  any
    jurisdiction by reason of this provision.
 
        (g) The registration rights set forth in this Section 11 are subject  to
    the  condition that the Designated Holder  shall provide the Registrant with
    such information with respect to  such holder's Registrable Securities,  the
    plans  for the distribution thereof, and such other information with respect
    to such holder as, in the reasonable judgment of counsel for the Registrant,
    is necessary  to  enable the  Registrant  to include  in  such  registration
    statement  all material  facts required  to be  disclosed with  respect to a
    registration thereunder.
 
        (h) A registration effected under this  Section 11 shall be effected  at
    the  Registrant's expense, except for underwriting discounts and commissions
    and the fees and the expenses of  counsel to the Designated Holder, and  the
    Registrant  shall provide to the  underwriters such documentation (including
    certificates, opinions of counsel and "comfort" letters from auditors) as is
    customary  in  connection  with   underwritten  public  offerings  as   such
    underwriters may reasonably require.
 
        (i)  In connection with any registration effected under this Section 11,
    the parties agree
 
           (i) to indemnify  each other  and the underwriters  in the  customary
       manner,
 
           (ii)  to enter into  an underwriting agreement  in form and substance
       customary for transactions of  such type with the  Manager and the  other
       underwriters participating in such offering, and
 
          (iii)  to take all further actions which shall be reasonably necessary
       to effect such registration and sale  (including if the Manager deems  it
       necessary, participating in road-show presentations).
 
        (j)    The Registrant  shall  be entitled  to  include (at  its expense)
    additional shares of its common stock in a registration effected pursuant to
    this Section 11 only if and to  the extent the Manager determines that  such
    inclusion  will  not  adversely affect  the  prospects for  success  of such
    offering.
 
    12.  ADJUSTMENT UPON CHANGES IN  CAPITALIZATION.  Without limitation to  any
restriction  on  OPTION GRANTOR  contained in  this Agreement  or in  the Merger
Agreement, in the event of any change  in OPTION GRANTOR Common Stock by  reason
of    stock   dividends,   splitups,   mergers    (other   than   the   Merger),
recapitalizations, combinations, exchange of  shares or the  like, the type  and
number  of shares or  securities subject to  the OPTION GRANTOR  Option, and the
purchase price per share provided in Section 1, shall be adjusted  appropriately
to  restore  to  OPTION HOLDER  its  rights  hereunder, including  the  right to
purchase from OPTION GRANTOR (or its successors) shares of OPTION GRANTOR Common
Stock (or such other shares or securities into which OPTION GRANTOR Common Stock
has been so changed)  representing the Option Shares  Percentage of the  Initial
Number of shares of OPTION GRANTOR Common Stock for the aggregate Exercise Price
calculated as of the date of this Agreement as provided in Section 1.
 
                                      F-11
<PAGE>
    13.    RESTRICTIVE LEGENDS.   Each  certificate representing  OPTION GRANTOR
Shares issued to  OPTION HOLDER  hereunder, and  OPTION HOLDER  Shares, if  any,
delivered   to  OPTION  GRANTOR  at  a   Closing,  shall  include  a  legend  in
substantially the following form:
 
    THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN  REGISTERED
    UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES OR
    BLUE  SKY LAWS, AND MAY BE REOFFERED OR SOLD ONLY IF SO REGISTERED OR IF
    AN EXEMPTION FROM  SUCH REGISTRATION IS  AVAILABLE. SUCH SECURITIES  ARE
    ALSO  SUBJECT TO ADDITIONAL RESTRICTIONS ON TRANSFER AS SET FORTH IN THE
    OPTION HOLDER STOCK OPTION  AND TRIGGER PAYMENT  AGREEMENT, DATED AS  OF
    NOVEMBER  10, 1995, A COPY OF WHICH MAY BE OBTAINED FROM THE ISSUER UPON
    REQUEST.
 
It is understood and agreed that:
 
        (i) the reference to the resale  restrictions of the Securities Act  and
    state  securities or Blue Sky  laws in the above  legend shall be removed by
    delivery of  substitute  certificate(s)  without such  reference  if  OPTION
    HOLDER  or OPTION GRANTOR, as  the case may be,  shall have delivered to the
    other party a copy of a letter from  the staff of the SEC, or an opinion  of
    counsel,  in  form and  substance satisfactory  to the  other party,  to the
    effect that such legend is not  required for purposes of the Securities  Act
    or such laws;
 
        (ii)  the reference  to the  provisions to  this Agreement  in the above
    legend shall be  removed by  delivery of  substitute certificate(s)  without
    such  reference if  the shares have  been sold or  transferred in compliance
    with the provisions of  this Agreement and under  circumstances that do  not
    require the retention of such reference; and
 
       (iii)  the legend shall be  removed in its entirety  if the conditions in
    the preceding clauses (i) and (ii) are both satisfied.
 
In addition, such certificates shall bear any other legend as may be required by
law. Certificates  representing  shares sold  in  a registered  public  offering
pursuant  to Section 11  shall not be required  to bear the  legend set forth in
this Section 13.
 
    14.  BINDING EFFECT; NO ASSIGNMENT; NO THIRD PARTY BENEFICIARIES.
 
        (a) This Agreement shall be binding upon and inure to the benefit of the
    parties hereto and their respective successors and permitted assigns.
 
        (b) Except as  expressly provided  for in this  Agreement, neither  this
    Agreement  nor  the  rights  or  obligations  of  either  party  hereto  are
    assignable, except by operation of law,  or with the written consent of  the
    other party.
 
        (c) Nothing contained in this Agreement, express or implied, is intended
    to confer upon any person other than the parties hereto and their respective
    successors  and  permitted  assigns any  rights  or remedies  of  any nature
    whatsoever by reason of this Agreement.
 
        (d) Any  Restricted  Shares sold  by  a  party in  compliance  with  the
    provisions  of Section 11 shall, upon consummation  of such sale, be free of
    the restrictions  imposed with  respect to  such shares  by this  Agreement,
    unless  and  until  such  party shall  repurchase  or  otherwise  become the
    beneficial owner of such shares, and any transferee of such shares shall not
    be entitled to the registration rights of such party.
 
    15.  SPECIFIC PERFORMANCE.  The  parties hereto agree that irreparable  harm
would  occur in the event that any of  the provisions of this Agreement were not
performed in accordance with their  specified terms or were otherwise  breached.
It  is  accordingly agreed  that  the parties  hereto  shall be  entitled  to an
injunction or injunctions to prevent breaches  of this Agreement and to  enforce
specifically  the terms and provisions hereof in  any court of the United States
or any state having jurisdiction, this being in addition to any other remedy  to
which they are entitled at law or equity.
 
                                      F-12
<PAGE>
    16.  VALIDITY.
 
        (a)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement shall  not affect  the  validity or  enforceability of  the  other
    provisions of this Agreement, which shall remain in full force and effect.
 
        (b)  In  the event  any  court or  other  competent authority  holds any
    provisions of this Agreement to be null, void or unenforceable, the  parties
    hereto  shall  negotiate in  good  faith the  execution  and delivery  of an
    amendment to this Agreement in order, as nearly as possible, to  effectuate,
    to  the  extent permitted  by law,  the  intent of  the parties  hereto with
    respect to such provision and the economic effects thereof.
 
        (c) Subject to Section 5, if for any reason any such court or regulatory
    agency determines that OPTION HOLDER is not permitted to acquire, or  OPTION
    GRANTOR  is  not permitted  to repurchase  pursuant to  Section 8,  the full
    number of shares of OPTION GRANTOR Common Stock provided in Section 1 hereof
    (as the same may be adjusted), it is the express intention of OPTION GRANTOR
    to allow OPTION HOLDER to acquire or to require OPTION GRANTOR to repurchase
    such lesser number of shares as may be permissible without any amendment  or
    modification hereof.
 
        (d)  Each  party  agrees  that,  should  any  court  or  other competent
    authority hold any provision  of this Agreement or  part hereof to be  null,
    void  or unenforceable, or  order any party to  take any action inconsistent
    herewith, or not take any action required herein, the other party shall  not
    be  entitled to specific performance of such  provision or part hereof or to
    any other remedy,  including but not  limited to money  damages, for  breach
    hereof  or of any  other provision of  this Agreement or  part hereof as the
    result of such holding or order.
 
    17.  NOTICES.   All notices and other  communications hereunder shall be  in
writing and shall be deemed given if (a) delivered personally, or (b) if sent by
overnight courier service (receipt confirmed in writing), or (c) if delivered by
facsimile  transmission (with receipt  confirmed), or (d)  five days after being
mailed by registered or certified mail (return receipt requested) to the parties
in each case to the following addresses (or at such other address for a party as
shall be specified by like notice):
 
    A.  If to OPTION HOLDER, to:
       WPL Holdings, Inc.
       222 West Washington Avenue
       Madison, Wisconsin 53703
       Attention: Erroll B. Davis, Jr.
       Fax: (608) 252-5059
       with a copy to:
       Foley & Lardner
       777 East Wisconsin Avenue
       Milwaukee, Wisconsin 53202-5367
       Attention: Benjamin F. Garmer, III, Esq.
       Fax: (414) 297-4900
 
                                      F-13
<PAGE>
    B.  If to OPTION GRANTOR, to:
       Interstate Power Company
       1000 Main Street
       Dubuque, Iowa 52004-0789
       Attention: Wayne H. Stoppelmoor
       Chairman
       Fax: (319) 557-2202
       with a copy to:
       Milbank, Tweed, Hadley & McCloy
       1 Chase Manhattan Plaza
       New York, New York 10005-1413
       Attention: John T. O'Connor, Esq.
       Fax: (212) 530-5219
 
    18.  GOVERNING LAW.   This Agreement shall be  governed by and construed  in
accordance  with the laws of the State of Delaware applicable to agreements made
and to be performed entirely within such State and without regard to its  choice
of law principles or to any requirement as to jurisdiction or service of process
contained in Section 2708 of Title 6 of the Delaware Code.
 
    19.  INTERPRETATION.
 
        (a)  When reference is  made in this Agreement  to Articles, Sections or
    Exhibits, such reference shall be to an Article, Section or Exhibit of  this
    Agreement, as the case may be, unless otherwise indicated.
 
        (b)  The table of contents and  headings contained in this Agreement are
    for reference  purposes and  shall not  affect  in any  way the  meaning  or
    interpretation of the Agreement.
 
        (c) Whenever the words "include," "includes," or "including" are used in
    this  Agreement, they shall be  deemed to be followed  by the words "without
    limitation."
 
        (d) Whenever "or" is used in this Agreement it shall be construed in the
    nonexclusive sense.
 
    20.  COUNTERPARTS; EFFECT.   This Agreement may be  executed in one or  more
counterparts,  each of which shall be deemed to be an original, but all of which
shall constitute one and the same agreement.
 
    21.   AMENDMENTS; WAIVER.   This  Agreement may  be amended  by the  parties
hereto  and the terms and conditions hereof  may be waived only by an instrument
in writing signed on behalf of each of the parties hereto, or, in the case of  a
waiver, by an instrument signed on behalf of the party waiving compliance.
 
    22.   EXTENSION OF TIME PERIODS.   The time periods for exercises of certain
rights under Sections 2, 7 and 8 shall be extended (but in no event by more than
six months):
 
        (a) to the extent necessary to  obtain all regulatory approvals for  the
    exercise  of such  rights, and for  the expiration of  all statutory waiting
    periods; and
 
        (b) to the extent necessary to  avoid any liability under Section  16(b)
    of the Exchange Act by reason of such exercise.
 
                                      F-14
<PAGE>
    IN  WITNESS WHEREOF,  the parties  hereto have  caused this  Agreement to be
executed by their respective duly authorized officers as of the date first above
written.
 
                                          INTERSTATE POWER COMPANY
 
                                          By: /s/ WAYNE H. STOPPELMOOR
 
                                          --------------------------------------
                                              Name: Wayne H. Stoppelmoor
                                              Title: Chairman of the Board,
                                                     President and Chief
                                                     Executive Officer
 
                                          WPL HOLDINGS, INC.
 
                                          By: /s/ ERROLL B. DAVIS, JR.
 
                                          --------------------------------------
                                              Name: Erroll B. Davis, Jr.
                                              Title: President and Chief
                                                     Executive Officer
 
                                      F-15
<PAGE>
                                                                         ANNEX G
 
                   OPTION GRANTOR/OPTION HOLDER STOCK OPTION
                         AND TRIGGER PAYMENT AGREEMENT
 
    This STOCK OPTION AGREEMENT, dated as of November 10, 1995 (the "AGREEMENT")
by and among Interstate Power Company, a corporation organized under the laws of
the  State of  Delaware ("OPTION GRANTOR"  or the "COMPANY")  and IES Industries
Inc., a  corporation organized  under the  laws of  the State  of Iowa  ("OPTION
HOLDER").
 
                         W I T N E S S E T H  T H A T:
 
    WHEREAS,  concurrently with  the execution  and delivery  of this Agreement,
OPTION GRANTOR, OPTION HOLDER, WPL Holdings, Inc., a corporation organized under
the laws of the State of Wisconsin ("WPL"), WPLH Acquisition Co., a wholly-owned
subsidiary  of  WPL  organized  under  the  laws  of  the  State  of   Wisconsin
("ACQUISITION"),  and  Interstate Power  Company,  a wholly-owned  subsidiary of
OPTION GRANTOR organized under the laws of the State of Wisconsin, are  entering
into  an Agreement and Plan of Merger, dated as of November 10, 1995, as amended
(the "MERGER AGREEMENT"), which provides, INTER ALIA, upon the terms and subject
to the conditions thereof, for the merger of OPTION HOLDER with and into WPL  in
accordance with the laws of the States of Wisconsin and Iowa (the "IES MERGER"),
and  the merger  of Acquisition  with and  into OPTION  GRANTOR (or  a successor
thereto) in accordance with the laws of the States of Delaware and/or  Wisconsin
(the "INTERSTATE MERGER, and together with the IES Merger, the "MERGER");
 
    WHEREAS,  in connection with  the execution of  the Merger Agreement, OPTION
GRANTOR, OPTION HOLDER and WPL are entering into certain stock option agreements
dated as of the date hereof, of which this Agreement is one, whereby the parties
hereto grant each other an option with respect to certain shares of each other's
common stock on the terms and subject  to the conditions set forth therein  (the
"STOCK OPTION AGREEMENTS"); and
 
    WHEREAS,  as a  condition to OPTION  HOLDER's willingness to  enter into the
Merger Agreement, OPTION  HOLDER has  requested that OPTION  GRANTOR agree,  and
OPTION  GRANTOR has so agreed, to grant  to OPTION HOLDER an option with respect
to certain shares of OPTION GRANTOR's common stock, on the terms and subject  to
the conditions set forth herein;
 
    NOW,  THEREFORE, to induce OPTION HOLDER  to enter into the Merger Agreement
and certain  of  the  Stock  Option Agreements,  and  in  consideration  of  the
representations,  warranties, covenants and agreements  contained herein, in the
Merger Agreement and in the Stock Option Agreements to which OPTION GRANTOR  and
OPTION  HOLDER are parties,  the parties hereto, intending  to be legally bound,
hereby agree as follows:
 
    1.  GRANT OF OPTION.
 
        (a) Subject  to  the receipt  of  all regulatory  approvals  and  orders
    required  by OPTION GRANTOR as set forth in Section 6.4(c) of the Interstate
    Disclosure Schedule to  the Merger  Agreement and  by OPTION  HOLDER as  set
    forth  in  Section  5.4(c) of  the  IES  Disclosure Schedule  to  the Merger
    Agreement, OPTION GRANTOR hereby grants OPTION HOLDER an irrevocable  option
    (the  "OPTION  GRANTOR OPTION")  to purchase  up to  that number  of shares,
    subject to  adjustment  as  provided  in Section  12  (the  "OPTION  GRANTOR
    SHARES"), of common stock, par value $3.50 per share, of OPTION GRANTOR (the
    "OPTION  GRANTOR COMMON  STOCK") equal to  a percentage  (the "OPTION SHARES
    PERCENTAGE"), which Option Shares Percentage is equal to the OPTION HOLDER's
    Participation Percentage as  defined below in  subsection (e), of  1,903,293
    shares  of OPTION GRANTOR Common Stock (being  19.9% of the number of shares
    of OPTION GRANTOR  Common Stock issued  and outstanding as  of November  10,
    1995 (the
 
                                      G-1
<PAGE>
    "INITIAL  NUMBER") in the manner set forth  below, at a price (the "EXERCISE
    PRICE") per OPTION  GRANTOR Share of  $28.9375 (which is  equal to the  Fair
    Market  Value (as defined below)  of an OPTION GRANTOR  Share as of the date
    hereof).
 
        (b) The Exercise Price shall be  payable, at OPTION HOLDER's option,  as
    follows:
 
           (i) in cash, or
 
           (ii)  subject to  the receipt  of all  approvals of  any Governmental
       Authority required for OPTION  GRANTOR to acquire,  and OPTION HOLDER  to
       issue, the OPTION HOLDER Shares (as defined below) from OPTION HOLDER, in
       shares  of common stock,  no par value, of  OPTION HOLDER ("OPTION HOLDER
       SHARES"),
 
    in either case in accordance with Section 4 hereof.
 
        (c) Notwithstanding  the foregoing,  in  no event  shall the  number  of
    OPTION  GRANTOR Shares  for which the  OPTION GRANTOR  Option is exercisable
    exceed the product of the Option  Shares Percentage and the Initial  Number,
    subject to adjustment as provided in Section 12.
 
        (d)  As used herein, the  "FAIR MARKET VALUE" of  any share shall be the
    average of the  daily closing sales  price for  such share on  the New  York
    Stock  Exchange (the "NYSE") during  the ten NYSE trading  days prior to the
    fifth NYSE trading day preceding  the date such Fair  Market Value is to  be
    determined.
 
        (e)  For purposes of this  Agreement the term "PARTICIPATION PERCENTAGE"
    shall have  the  same  meaning  as  in  Section  10.3(f)(i)  of  the  Merger
    Agreement,  except that  the numerator  and denominator  shall be calculated
    based on the number of  shares of WPL Common  Stock which would be  issuable
    (or,  in the case of  WPL, retained by its  shareholders) on a fully diluted
    basis had the Effective Time occurred as  of the date on which the  Exercise
    Notice  is delivered under Section 2 hereof  or the date on which demand for
    the Trigger Payment (as defined herein) is given under Section 5 hereof,  as
    the  case may be. Other capitalized terms used herein but not defined herein
    shall have the meanings set forth in the Merger Agreement.
 
    2.  EXERCISE OF OPTION.
 
        (a) The OPTION  GRANTOR Option  may be  exercised by  OPTION HOLDER,  in
    whole  or  in part,  at  any time  or  from time  to  time after  the Merger
    Agreement becomes  terminable by  OPTION  HOLDER under  circumstances  which
    could  entitle OPTION HOLDER  to a termination fee  under Section 10.3(a) of
    the  Merger  Agreement  (provided  that  the  events  specified  in  Section
    10.3(a)(ii)(A)  of the  Merger Agreement  shall have  occurred, although the
    events specified in Section 10.3(a)(ii)(B) thereof need not have  occurred),
    or Section 10.3(b) of the Merger Agreement (regardless of whether the Merger
    Agreement  is actually terminated  or whether there occurs  a closing of any
    Business Combination involving a Target Party or a closing by which a Target
    Party becomes a Subsidiary),  any such event by  which the Merger  Agreement
    becomes  so  terminable  by OPTION  HOLDER  being  referred to  herein  as a
    "TRIGGER EVENT").
 
         (b)(i) OPTION GRANTOR shall notify OPTION HOLDER promptly in writing of
       the occurrence of any Trigger Event, it being understood that the  giving
       of such notice by OPTION GRANTOR shall not be a condition to the right of
       OPTION HOLDER to exercise the OPTION GRANTOR Option.
 
           (ii) In the event OPTION HOLDER wishes to exercise the OPTION GRANTOR
       Option,  OPTION HOLDER shall deliver to OPTION GRANTOR written notice (an
       "EXERCISE NOTICE") specifying the total  number of OPTION GRANTOR  Shares
       it wishes to purchase.
 
          (iii)  Upon  the giving  by  OPTION HOLDER  to  OPTION GRANTOR  of the
       Exercise Notice  and  the tender  of  the applicable  aggregate  Exercise
       Price, OPTION HOLDER, to the extent permitted by law and OPTION GRANTOR's
       organizational  documents,  and provided  that  the conditions  to OPTION
       GRANTOR's obligation to issue the OPTION GRANTOR
 
                                      G-2
<PAGE>
       Shares to  OPTION HOLDER  hereunder  set forth  in  Section 3  have  been
       satisfied  or waived, shall be  deemed to be the  holder of record of the
       OPTION GRANTOR Shares issuable  upon such exercise, notwithstanding  that
       the  stock transfer books of OPTION GRANTOR  shall then be closed or that
       certificates representing such  OPTION GRANTOR Shares  shall not then  be
       actually delivered to OPTION HOLDER.
 
          (iv) Each closing of a purchase of OPTION GRANTOR Shares (a "CLOSING")
       shall  occur at a  place, on a date,  and at a  time designated by OPTION
       HOLDER in an Exercise Notice delivered  at least two business days  prior
       to the date of the Closing.
 
        (c) The OPTION GRANTOR Option shall terminate upon the earliest to occur
    of:
 
           (i) the Effective Time of the Merger;
 
           (ii) the termination of the Merger Agreement pursuant to Section 10.1
       thereof,  other than under circumstances  which also constitute a Trigger
       Event under this Agreement;
 
          (iii) 180 days following any termination of the Merger Agreement  upon
       or during the continuance of a Trigger Event (or if, at the expiration of
       such  180 day  period, the OPTION  GRANTOR Option cannot  be exercised by
       reason of any applicable judgment, decree, order, law or regulation,  ten
       business  days after such impediment to  exercise shall have been removed
       or shall have become  final and not  subject to appeal,  but in no  event
       under this clause (iii) later than May 10, 1998); and
 
          (iv)  payment by  OPTION GRANTOR of  the Trigger Payment  set forth in
       Section 5 of this Agreement to OPTION HOLDER.
 
        (d) Notwithstanding the foregoing, the OPTION GRANTOR Option may not  be
    exercised  if  (i)  OPTION  HOLDER  is in  material  breach  of  any  of its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in  this Agreement or in  the Merger Agreement,  or
    (ii) a Trigger Payment has been paid pursuant to Section 5 of this Agreement
    or demand therefor has been made and not withdrawn.
 
    3.   CONDITIONS TO CLOSING.   The obligation of  OPTION GRANTOR to issue the
OPTION GRANTOR Shares to  OPTION HOLDER hereunder is  subject to the  conditions
that
 
        (a)  all waiting periods,  if any, under  the HSR Act  applicable to the
    issuance and acquisition of the  OPTION GRANTOR Shares hereunder shall  have
    expired or have been terminated;
 
        (b)  the OPTION GRANTOR  Shares, and any OPTION  HOLDER Shares which are
    issued in  payment of  the  Exercise Price,  shall  have been  approved  for
    listing on the NYSE subject only to official notice of issuance;
 
        (c)   all  consents,   approvals,  orders   or  authorizations   of,  or
    registrations, declarations or  filings with,  any federal,  state or  local
    administrative  agency  or  commission  or  other  federal,  state  or local
    Governmental Authority, if any, required in connection with the issuance  by
    OPTION  GRANTOR and the  acquisition by OPTION HOLDER  of the OPTION GRANTOR
    Shares hereunder  shall  have  been obtained  or  made,  including,  without
    limitation,  the approval of the  SEC under Sections 9  and 10 of the Public
    Utility Holding  Company Act  of  1935, as  amended  (the "1935  ACT"),  the
    approval  of  the Iowa  Utilities Board,  the  Public Service  Commission of
    Minnesota and the Illinois Commerce Commission of the issuance of the OPTION
    GRANTOR Shares  by OPTION  GRANTOR and,  if applicable,  the acquisition  of
    OPTION  GRANTOR  Shares  by OPTION  HOLDER,  and  the approval  of  the Iowa
    Utilities Board of the  acquisition of the OPTION  GRANTOR Shares by  OPTION
    HOLDER  and, if applicable, the acquisition  by OPTION GRANTOR of the OPTION
    HOLDER Shares constituting the Exercise Price hereunder; and
 
                                      G-3
<PAGE>
        (d) no preliminary or permanent injunction  or other order by any  court
    of competent jurisdiction prohibiting or otherwise restraining such issuance
    shall be in effect.
 
The  condition set forth in paragraph (b) above may be waived by OPTION GRANTOR,
in the case of OPTION HOLDER Shares, and by OPTION HOLDER, in the case of OPTION
GRANTOR Shares, in the sole discretion of the waiving party.
 
    4.  CLOSING.  At any Closing,
 
        (a) OPTION GRANTOR  shall deliver  to OPTION  HOLDER or  its designee  a
    single  certificate  in definitive  form representing  the number  of OPTION
    GRANTOR Shares  designated by  OPTION HOLDER  in its  Exercise Notice,  such
    certificate  to be registered in  the name of OPTION  HOLDER and to bear the
    legend set forth in Section 13; and
 
        (b) OPTION HOLDER shall  deliver to OPTION  GRANTOR the aggregate  price
    for the OPTION GRANTOR Shares so designated and being purchased by
 
           (i)  wire transfer of immediately  available funds or certified check
       or bank check, or
 
           (ii) subject  to the  condition in  Section 1(b)(ii),  delivery of  a
       certificate  or  certificates representing  the  number of  OPTION HOLDER
       Shares being issued by OPTION HOLDER in consideration thereof, determined
       in accordance with Section 4(c).
 
        (c) In  the event  that OPTION  HOLDER issues  OPTION HOLDER  Shares  to
    OPTION GRANTOR in consideration of OPTION GRANTOR Shares pursuant to Section
    4(b)(ii),  the number of OPTION HOLDER Shares to be so issued shall be equal
    to the quotient obtained by dividing:
 
           (i) the  product of  (x) the  number of  OPTION GRANTOR  Shares  with
       respect to which the OPTION GRANTOR Option is being exercised and (y) the
       Exercise Price, by
 
           (ii) the Fair Market Value of the OPTION HOLDER Shares as of the date
       immediately preceding the date the Exercise Notice is delivered to OPTION
       GRANTOR.
 
        (d)  OPTION GRANTOR  shall pay  all expenses,  and any  and all Federal,
    state and local taxes  and other charges that  may be payable in  connection
    with  the preparation, issue  and delivery of  stock certificates under this
    Section 4.
 
    5.  TRIGGER PAYMENT.
 
        (a)  TRIGGER PAYMENT.  Subject  to the provisions of Section 10.3(e)  of
    the  Merger  Agreement,  if a  Trigger  Event  shall have  occurred  and any
    regulatory approval or order required for the issuance by OPTION GRANTOR, or
    the acquisition by OPTION HOLDER, of  the OPTION GRANTOR Option pursuant  to
    Section  1 hereof shall not have been obtained, OPTION HOLDER shall have the
    right to receive, and OPTION GRANTOR  shall pay to OPTION HOLDER, an  amount
    (the "TRIGGER PAYMENT") equal to the product of
 
           (i)  the maximum number of OPTION GRANTOR Shares that would have been
       subject to purchase by OPTION HOLDER upon exercise of the OPTION  GRANTOR
       Option  pursuant  to  Sections 1  and  2  hereof if  all  such regulatory
       approvals or orders had been obtained, and
 
           (ii) the difference  between (A) the  Market/Offer Price (as  defined
       herein),  determined as  of the  date on which  notice of  demand for the
       Trigger Payment is  given by OPTION  HOLDER, and (B)  the Exercise  Price
       (but only if such Market/Offer Price is higher than such Exercise Price).
 
    Demand  for the Trigger Payment shall be  given by notice in accordance with
    the provisions of Section  17 hereof. The Trigger  Payment shall be paid  to
    OPTION HOLDER by OPTION
 
                                      G-4
<PAGE>
    GRANTOR  on  the  Payment Date  (as  defined  herein), by  wire  transfer of
    immediately available funds  to an account  to be designated  in writing  by
    OPTION HOLDER not less than two business days before the Payment Date.
 
        (b)  PAYMENT DATE.  For purposes of this Section 5, "PAYMENT DATE" means
    the date on which termination fees are required to be paid by OPTION GRANTOR
    to  OPTION HOLDER under Section  10.3(a) or 10.3(b), as  the case may be, of
    the Merger Agreement  as a  result of the  occurrence of  the Trigger  Event
    referred to in subsection (a) of this Section 5.
 
        (c)  CERTAIN CONDITIONS.  OPTION GRANTOR shall have no obligation to pay
    the  Trigger Payment if  OPTION HOLDER is  in material breach  of any of its
    representations or warranties, or in material breach of any of its covenants
    or agreements, contained in this Agreement or in the Merger Agreement.
 
    6.   REPRESENTATIONS  AND WARRANTIES  OF  OPTION GRANTOR.    OPTION  GRANTOR
represents and warrants to OPTION HOLDER that
 
        (a)  except as set forth in  Section 6.4(a) of the Interstate Disclosure
    Schedule to the Merger Agreement, OPTION GRANTOR has the corporate power and
    authority to enter  into this  Agreement and  to carry  out its  obligations
    hereunder,  subject  in the  case of  the repurchase  of the  OPTION GRANTOR
    Shares pursuant to  Section 8(a)  to applicable  law and  the provisions  of
    OPTION  GRANTOR's Articles of Incorporation, as amended (the "OPTION GRANTOR
    ARTICLES");
 
        (b) this Agreement has been duly  and validly executed and delivered  by
    OPTION  GRANTOR, and, assuming the due authorization, execution and delivery
    hereof  by  OPTION  HOLDER  and  the  receipt  of  all  required  regulatory
    approvals,  constitutes a  valid and  binding obligation  of OPTION GRANTOR,
    enforceable against OPTION GRANTOR in  accordance with its terms, except  as
    may be limited by applicable bankruptcy, insolvency, reorganization or other
    similar  laws affecting the enforcement  of creditors' rights generally, and
    except that  the  availability  of equitable  remedies,  including  specific
    performance,  may be subject to the discretion of any court before which any
    proceeding therefor may be brought;
 
        (c) OPTION GRANTOR has taken all necessary corporate action to authorize
    and reserve for issuance  and to permit  it to issue,  upon exercise of  the
    OPTION  GRANTOR Option, and  at all times  from the date  hereof through the
    expiration of  the OPTION  GRANTOR Option  will have  reserved, the  Initial
    Number  of authorized and unissued OPTION  GRANTOR Shares, such amount being
    subject to adjustment as  provided in Section 12,  all of which, upon  their
    issuance  and delivery in accordance with  the terms of this Agreement, will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d) upon delivery of the OPTION GRANTOR Shares to OPTION HOLDER upon the
    exercise of the OPTION GRANTOR Option, OPTION HOLDER will acquire the OPTION
    GRANTOR Shares free and  clear of all  claims, liens, charges,  encumbrances
    and security interests of any nature whatsoever;
 
        (e)  except as described in Section  6.4(b) of the Interstate Disclosure
    Schedule to  the  Merger  Agreement,  the execution  and  delivery  of  this
    Agreement  by  OPTION  GRANTOR does  not,  and, subject  to  compliance with
    applicable  law  and  the  OPTION  GRANTOR  Articles  with  respect  to  the
    repurchase  of  the  OPTION GRANTOR  Shares  pursuant to  Section  8(a), the
    consummation by OPTION GRANTOR of the transactions contemplated hereby  will
    not  violate, conflict with, or  result in a breach  of any provision of, or
    constitute a default (with or  without notice or a  lapse of time, or  both)
    under,  or  result  in the  termination  of, or  accelerate  the performance
    required  by,  or  result  in  a  right  of  termination,  cancellation,  or
    acceleration  of any obligation or the loss  of a material benefit under, or
    the creation of a  lien, pledge, security interest  or other encumbrance  on
 
                                      G-5
<PAGE>
    assets  (any  such  conflict,  violation,  default,  right  of  termination,
    cancellation, acceleration, loss or creation, hereinafter a "VIOLATION")  of
    OPTION GRANTOR or any of its Subsidiaries, pursuant to
 
           (i)  any provision  of the OPTION  GRANTOR Articles or  the Bylaws of
       OPTION GRANTOR,
 
           (ii) any provisions of any  material loan or credit agreement,  note,
       mortgage,  indenture, lease, benefit plan or other agreement, obligation,
       instrument,  permit,  concession,  franchise  or  license  (any  of   the
       foregoing  in effect on the date hereof  being referred to as a "MATERIAL
       CONTRACT") of OPTION GRANTOR or its subsidiaries or to which any of  them
       is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable to OPTION GRANTOR or its properties or assets,
 
    which Violation,  in  the  case  of  each  clauses  (ii)  and  (iii),  could
    reasonably  be expected  to have an  OPTION GRANTOR  Material Adverse Effect
    (except that no representation or warranty is given concerning any Violation
    of a Material  Contract with  respect to  the repurchase  of OPTION  GRANTOR
    Shares pursuant to Section 8(a));
 
        (f)  except as described in Section  6.4(c) of the Interstate Disclosure
    Schedule to the Merger Agreement or Section 1 or 3 hereof, the execution and
    delivery of this Agreement by OPTION  GRANTOR does not, and the  performance
    of this Agreement by OPTION GRANTOR will not, require any consent, approval,
    authorization or permit of, filing with or notification to, any Governmental
    Authority;
 
        (g)  none of OPTION GRANTOR,  any of its affiliates  or anyone acting on
    its or their  behalf, has  issued, sold or  offered any  security of  OPTION
    GRANTOR  to any person under circumstances that would cause the issuance and
    sale of OPTION  GRANTOR Shares,  as contemplated  by this  Agreement, to  be
    subject  to the registration requirements of the Securities Act as in effect
    on the  date hereof,  and, assuming  the representations  and warranties  of
    OPTION  HOLDER contained in Section 7(g) are true and correct, the issuance,
    sale and delivery  of the OPTION  GRANTOR Shares hereunder  would be  exempt
    from the registration and prospectus delivery requirements of the Securities
    Act,  as in effect on the date hereof (and OPTION GRANTOR shall not take any
    action which would cause the issuance, sale, and delivery of OPTION  GRANTOR
    Shares hereunder not to be exempt from such requirements); and
 
        (h) any OPTION HOLDER Shares acquired pursuant to this Agreement will be
    acquired for OPTION GRANTOR's own account, for investment purposes only, and
    will  not  be  acquired  by  OPTION  GRANTOR  with  a  view  to  the  public
    distribution thereof  in  violation  of  any  applicable  provision  of  the
    Securities Act.
 
    7.    REPRESENTATIONS  AND  WARRANTIES  OF  OPTION  HOLDER.    OPTION HOLDER
represents and warrants to OPTION GRANTOR that
 
        (a) except  as  set forth  in  Schedule  5.4(a) of  the  IES  Disclosure
    Schedule  to the Merger Agreement, OPTION HOLDER has the corporate power and
    authority to enter  into this  Agreement and  to carry  out its  obligations
    hereunder;
 
        (b)  this Agreement has been duly  and validly executed and delivered by
    OPTION HOLDER and,  assuming the due  authorization, execution and  delivery
    hereof  by  OPTION  GRANTOR  and  the  receipt  of  all  required regulatory
    approvals, constitutes  a valid  and binding  obligation of  OPTION  HOLDER,
    enforceable  against OPTION HOLDER in  accordance with its respective terms,
    except  as   may   be   limited  by   applicable   bankruptcy,   insolvency,
    reorganization,   or  other  similar  laws   affecting  the  enforcement  of
    creditors' rights generally, and except  that the availability of  equitable
    remedies,  including specific performance, may  be subject to the discretion
    of any court before which any proceeding may be brought;
 
                                      G-6
<PAGE>
        (c) prior to any  delivery of OPTION HOLDER  Shares in consideration  of
    the  purchase of OPTION  GRANTOR Shares pursuant  hereto, OPTION HOLDER will
    have taken all necessary corporate action  to authorize for issuance and  to
    permit  it to  issue such  OPTION HOLDER  Shares, all  of which,  upon their
    issuance and delivery in accordance with  the terms of this Agreement,  will
    be duly authorized, validly issued, fully paid and nonassessable;
 
        (d)  upon any delivery of such OPTION HOLDER Shares to OPTION GRANTOR in
    consideration of  the purchase  of OPTION  GRANTOR Shares  pursuant  hereto,
    OPTION  GRANTOR will acquire the OPTION HOLDER  Shares free and clear of all
    claims, liens, charges,  encumbrances and security  interests of any  nature
    whatsoever;
 
        (e) except as described in Section 5.4(b) of the IES Disclosure Schedule
    to  the Merger  Agreement, the execution  and delivery of  this Agreement by
    OPTION HOLDER  does  not, and  the  consummation  by OPTION  HOLDER  of  the
    transactions contemplated hereby will not, violate, conflict with, or result
    in  the breach of any provision of, or constitute a default (with or without
    notice or a lapse  of time, or  both) under, or result  in any Violation  by
    OPTION HOLDER or any of its Subsidiaries, pursuant to
 
           (i)  any  provision of  the Articles  of  Incorporation or  Bylaws of
       OPTION HOLDER,
 
           (ii)  any  Material  Contract  of   OPTION  HOLDER  or  any  of   its
       subsidiaries or to which any of them is a party, or
 
          (iii)  any judgment, order,  decree, statute, law,  ordinance, rule or
       regulation applicable to OPTION HOLDER or its properties or assets,
 
    which Violation, in the case of each of clauses (ii) or (iii), would have an
    OPTION HOLDER Material Adverse Effect;
 
        (f) except as described in Section 5.4(c) of the IES Disclosure Schedule
    to the Merger Agreement or Section 1 or 3 hereof, the execution and delivery
    of this Agreement by OPTION HOLDER does not, and the consummation by  OPTION
    HOLDER  of  the  transactions  contemplated  hereby  will  not,  require any
    consent, approval, authorization or permit  of, filing with or  notification
    to, any Governmental Authority; and
 
        (g)  any  OPTION GRANTOR  Shares acquired  upon  exercise of  the OPTION
    GRANTOR Option  will  be  acquired  for OPTION  HOLDER's  own  account,  for
    investment  purposes only and will not be,  and the OPTION GRANTOR Option is
    not being, acquired by OPTION HOLDER with a view to the public  distribution
    thereof, in violation of any applicable provision of the Securities Act.
 
    8.  CERTAIN REPURCHASES.
 
        (a)   OPTION HOLDER "PUT".   At the request  of OPTION HOLDER by written
    notice (x) at any time during which the OPTION GRANTOR Option is exercisable
    pursuant to  Section 2  (the "REPURCHASE  PERIOD"), OPTION  GRANTOR (or  any
    successor  entity thereof) shall, if permitted by applicable law, the OPTION
    GRANTOR  Articles  and  Bylaws  and  OPTION  GRANTOR's  Material  Contracts,
    repurchase  from  OPTION HOLDER  all or  any portion  of the  OPTION GRANTOR
    Option, at the price  set forth in  subparagraph (i) below,  or, (y) at  any
    time prior to May 10, 1997 (provided that such date shall be extended to May
    10, 1998 under the circumstances where the date after which either party may
    terminate  the Merger  Agreement pursuant to  Section 10.1(b)  of the Merger
    Agreement has  been  extended to  May  10,  1998), OPTION  GRANTOR  (or  any
    successor  entity  thereof)  shall,  if  permitted  by  applicable  law, the
 
                                      G-7
<PAGE>
    OPTION GRANTOR Articles and Bylaws and OPTION GRANTOR's Material  Contracts,
    repurchase  from  OPTION HOLDER  all or  any portion  of the  OPTION GRANTOR
    Shares purchased by OPTION HOLDER pursuant to the OPTION GRANTOR Option,  at
    the price set forth in subparagraph (ii) below:
 
         (i)(A)  The  difference between  the  "Market/Offer Price"  (as defined
       below) for shares of  OPTION GRANTOR Common Stock  as of the date  OPTION
       HOLDER  gives  notice of  its intent  to exercise  its rights  under this
       Section 8 and  the Exercise  Price, multiplied  by the  number of  OPTION
       GRANTOR  Shares  purchasable pursuant  to the  OPTION GRANTOR  Option (or
       portion thereof with  respect to  which OPTION HOLDER  is exercising  its
       rights  under  this Section  8), but  only if  the Market/Offer  Price is
       greater than the Exercise Price.
 
           (B) For purposes of this Agreement, "MARKET/OFFER PRICE" shall  mean,
       as  of any date, the higher of (I) the price per share offered as of such
       date pursuant to any tender or exchange offer or other offer with respect
       to a Business Combination  involving OPTION GRANTOR  as the Target  Party
       which  was made prior to such date  and not terminated or withdrawn as of
       such date and (II) the Fair  Market Value of OPTION GRANTOR Common  Stock
       as of such date.
 
        (ii)(A)  The product of  (I) the sum  of (a) the  Exercise Price paid by
       OPTION HOLDER per OPTION  GRANTOR Share acquired  pursuant to the  OPTION
       GRANTOR  Option, and  (b) the  difference between  the "Offer  Price" (as
       defined below) and  the Exercise Price,  but only if  the Offer Price  is
       greater  than the Exercise  Price, and (II) the  number of OPTION GRANTOR
       Shares so to be repurchased pursuant to this Section 8.
 
           (B) For purposes of this clause (ii), the "OFFER PRICE" shall be  the
       highest price per share offered pursuant to a tender or exchange offer or
       other  Business Combination offer involving  OPTION GRANTOR as the Target
       Party during the Repurchase Period prior to the delivery by OPTION HOLDER
       of a notice of repurchase.
 
        (b)  REDELIVERY OF  OPTION HOLDER SHARES.   If OPTION HOLDER shall  have
    previously  elected  to  purchase  OPTION  GRANTOR  Shares  pursuant  to the
    exercise of the OPTION GRANTOR Option by the issuance and delivery of OPTION
    HOLDER Shares, then OPTION GRANTOR shall, if so requested by OPTION  HOLDER,
    in  fulfillment of its obligation pursuant to Section 8(a)(y) (that is, with
    respect to the Exercise Price only and without limitation to its  obligation
    to pay additional consideration under clause (b) of Section 8(a)(ii)(A)(I)),
    redeliver  the certificates for such OPTION  HOLDER Shares to OPTION HOLDER,
    free and clear of all liens, claims, charges and encumbrances of any kind or
    nature whatsoever; PROVIDED, HOWEVER, that if  at any time less than all  of
    the  OPTION GRANTOR  Shares so  purchased by  OPTION HOLDER  pursuant to the
    OPTION GRANTOR Option are  to be repurchased by  OPTION GRANTOR pursuant  to
    Section  8(a)(y), then (i) OPTION GRANTOR shall be obligated to redeliver to
    OPTION HOLDER the same proportion of such OPTION HOLDER Shares as the number
    of OPTION GRANTOR Shares that OPTION GRANTOR is then obligated to repurchase
    bears to the number of OPTION GRANTOR Shares acquired by OPTION HOLDER  upon
    exercise  of the OPTION GRANTOR Option and (ii) OPTION HOLDER shall issue to
    OPTION GRANTOR  new certificates  representing  those OPTION  HOLDER  Shares
    which  are  not due  to be  redelivered  to OPTION  HOLDER pursuant  to this
    Section 8(b) to the extent that excess OPTION HOLDER Shares are included  in
    the certificates redelivered to OPTION HOLDER by OPTION GRANTOR.
 
        (c)   PAYMENT AND REDELIVERY OF OPTION GRANTOR OPTIONS OR SHARES. In the
    event OPTION  HOLDER  exercises its  rights  under this  Section  8,  OPTION
    GRANTOR  shall, within ten business days thereafter, pay the required amount
    to OPTION  HOLDER in  immediately available  funds and  OPTION HOLDER  shall
    surrender  to OPTION GRANTOR the OPTION GRANTOR Option or the certificate or
    certificates evidencing the OPTION GRANTOR Shares purchased by OPTION HOLDER
    pursuant hereto, and OPTION HOLDER shall warrant
 
                                      G-8
<PAGE>
    that it owns the OPTION  GRANTOR Option or such  shares and that the  OPTION
    GRANTOR  Option or such shares are then free and clear of all liens, claims,
    damages, charges and encumbrances of any kind or nature whatsoever.
 
        (d)  OPTION  HOLDER "CALL".   If OPTION HOLDER  has elected to  purchase
    OPTION  GRANTOR Shares pursuant to the exercise of the OPTION GRANTOR Option
    by the issuance and delivery  of OPTION HOLDER Shares, notwithstanding  that
    OPTION  HOLDER may  no longer  hold any such  OPTION GRANTOR  Shares or that
    OPTION HOLDER elects not to exercise its other rights under this Section  8,
    OPTION HOLDER may require, at any time or from time to time prior to May 10,
    1997  (provided that such date  shall be extended to  May 10, 1998 under the
    circumstances where  the date  after which  either party  may terminate  the
    Merger  Agreement pursuant  to Section 10.1(b)  of the  Merger Agreement has
    been extended to May 10, 1998), OPTION GRANTOR to sell to OPTION HOLDER  any
    such  OPTION HOLDER  Shares at  the price  attributed to  such OPTION HOLDER
    Shares pursuant to Section 4 plus interest at the rate of 8.75% per annum on
    such amount from the  Closing Date relating to  the exchange of such  OPTION
    HOLDER  Shares pursuant to Section 4 to  the Closing Date under this Section
    8(d) less any dividends on such OPTION HOLDER Shares paid during such period
    or declared and  payable to  stockholders of record  on a  date during  such
    period.
 
        (e)   REPURCHASE PRICE REDUCED AT OPTION  HOLDER'S OPTION.  In the event
    the repurchase price specified in Section 8(a) would subject the purchase of
    the OPTION GRANTOR Option or the  OPTION GRANTOR Shares purchased by  OPTION
    HOLDER  pursuant to the OPTION GRANTOR Option  to a vote of the shareholders
    of OPTION GRANTOR pursuant to applicable law or the OPTION GRANTOR Articles,
    then OPTION HOLDER may, at its  election, reduce the repurchase price to  an
    amount  which would permit such repurchase  without the necessity for such a
    shareholder vote.
 
    9.  VOTING  OF SHARES.   Following the date  hereof and prior  to the  fifth
anniversary  of the date  hereof (the "EXPIRATION DATE"),  each party shall vote
any shares of capital stock of the  other party acquired by such party  pursuant
to  this  Agreement ("RESTRICTED  SHARES"), including  any OPTION  HOLDER Shares
issued pursuant to  Section 1(b),  or otherwise beneficially  owned (within  the
meaning  of Rule 13d-3 promulgated under the Securities Exchange Act of 1934, as
amended (the "EXCHANGE ACT")), by such party on each matter submitted to a  vote
of  shareholders of  such other party  for and  against such matter  in the same
proportion as the vote of all other  shareholders of such other party are  voted
(whether by proxy or otherwise) for and against such matter.
 
    10.  RESTRICTIONS ON TRANSFER.
 
        (a)   RESTRICTIONS ON  TRANSFER.  Prior to  the Expiration Date, neither
    party shall, directly or indirectly, by operation of law or otherwise, sell,
    assign, pledge, or otherwise  dispose of or  transfer any Restricted  Shares
    beneficially  owned by such party, other than  (i) pursuant to Section 8, or
    (ii) in accordance with Section 10(b) or Section 11.
 
        (b)    PERMITTED  SALES.    Following  the  termination  of  the  Merger
    Agreement,  a  party  shall  be  permitted  to  sell  any  Restricted Shares
    beneficially owned  by it  if such  sale is  made pursuant  to a  tender  or
    exchange   offer  that  has  been  approved  or  recommended,  or  otherwise
    determined to be fair to  and in the best  interests of the shareholders  of
    the  other party, by a majority of the  members of the Board of Directors of
    such other party, which majority shall  include a majority of directors  who
    were directors prior to the announcement of such tender or exchange offer.
 
                                      G-9
<PAGE>
    11.  REGISTRATION RIGHTS.
 
        (a)  Following  the termination  of the  Merger Agreement,  either party
    hereto that owns Restricted  Shares (a "DESIGNATED  HOLDER") may by  written
    notice  (the "REGISTRATION  NOTICE") to  the other  party (the "REGISTRANT")
    request the Registrant to register under the Securities Act all or any  part
    of  the Restricted Shares beneficially owned  by such Designated Holder (the
    "REGISTRABLE  SECURITIES")  pursuant   to  a  bona   fide  firm   commitment
    underwritten  public  offering,  in  which  the  Designated  Holder  and the
    underwriters shall  effect  as  wide  a  distribution  of  such  Registrable
    Securities  as is reasonably practicable and shall use their best efforts to
    prevent any person  (including any Group  (as used in  Rule 13d-5 under  the
    Exchange  Act))  and its  affiliates from  purchasing through  such offering
    Restricted Shares representing  more than  1% of the  outstanding shares  of
    common  stock  of the  Registrant  on a  fully  diluted basis  (a "PERMITTED
    OFFERING").
 
        (b) The Registration Notice shall include a certificate executed by  the
    Designated  Holder and its proposed  managing underwriter, which underwriter
    shall be an investment banking  firm of nationally recognized standing  (the
    "MANAGER"), stating that
 
           (i) they have a good faith intention to commence promptly a Permitted
       Offering, and
 
           (ii)   the  manager  in  good  faith  believes  that,  based  on  the
       then-prevailing  market  conditions,  it  will   be  able  to  sell   the
       Registrable  Securities at a per share price equal to at least 80% of the
       then Fair Market Value of such shares.
 
        (c) The  Registrant (and/or  any person  designated by  the  Registrant)
    shall  thereupon have the option exercisable  by written notice delivered to
    the Designated Holder  within ten  business days  after the  receipt of  the
    Registration Notice, irrevocably to agree to purchase all or any part of the
    Registrable  Securities proposed  to be  so sold  for cash  at a  price (the
    "OPTION PRICE")  equal to  the  product of  (i)  the number  of  Registrable
    Securities  to be  so purchased  by the  Registrant and  (ii) the  then Fair
    Market Value of such shares.
 
        (d) Any purchase  of Registrable  Securities by the  Registrant (or  its
    designee)  under Section 11(c) shall  take place at a  closing to be held at
    the principal executive offices of the  Registrant or at the offices of  its
    counsel  at any reasonable date and time designated by the Registrant and/or
    such designee in such notice within  twenty business days after delivery  of
    such notice, and any payment for the shares to be so purchased shall be made
    by delivery at the time of such closing in immediately available funds.
 
        (e)  If the Registrant does not elect to exercise its option pursuant to
    this Section 11 with respect to all Registrable Securities, it shall use its
    best efforts to effect, as  promptly as practicable, the registration  under
    the  Securities Act of the unpurchased Registrable Securities proposed to be
    so sold; PROVIDED, HOWEVER, that
 
           (i) neither party shall be entitled to demand more than an  aggregate
       of two effective registration statements hereunder, and
 
           (ii)   the  Registrant  will  not  be   required  to  file  any  such
       registration statement during any period of  time (not to exceed 40  days
       after such request in the case of clause (A) below or 90 days in the case
       of clauses (B) and (C) below) when
 
               (A)  the  Registrant  is  in  possession  of  material non-public
           information which it reasonably believes  would be detrimental to  be
           disclosed  at  such  time  and,  in the  opinion  of  counsel  to the
           Registrant, such information would be  required to be disclosed if  a
           registration statement were filed at that time;
 
               (B)  the  Registrant  is  required under  the  Securities  Act to
           include  audited  financial  statements   for  any  period  in   such
           registration  statement  and such  financial  statements are  not yet
           available for inclusion in such registration statement; or
 
                                      G-10
<PAGE>
               (C) the Registrant determines,  in its reasonable judgment,  that
           such  registration would interfere with any financing, acquisition or
           other material transaction  involving the  Registrant or  any of  its
           affiliates.
 
        (f)  The Registrant shall  use its reasonable best  efforts to cause any
    Registrable  Securities  registered  pursuant  to  this  Section  11  to  be
    qualified   for  sale  under  the  securities  or  Blue  Sky  laws  of  such
    jurisdictions as  the Designated  Holder may  reasonably request  and  shall
    continue  such registration or qualification in effect in such jurisdiction;
    PROVIDED, HOWEVER, that the Registrant shall  not be required to qualify  to
    do   business  in,  or  consent  to  general  service  of  process  in,  any
    jurisdiction by reason of this provision.
 
        (g) The registration rights set forth in this Section 11 are subject  to
    the  condition that the Designated Holder  shall provide the Registrant with
    such information with respect to  such holder's Registrable Securities,  the
    plans  for the distribution thereof, and such other information with respect
    to such holder as, in the reasonable judgment of counsel for the Registrant,
    is necessary  to  enable the  Registrant  to include  in  such  registration
    statement  all material  facts required  to be  disclosed with  respect to a
    registration thereunder.
 
        (h) A registration effected under this  Section 11 shall be effected  at
    the  Registrant's expense, except for underwriting discounts and commissions
    and the fees and the expenses of  counsel to the Designated Holder, and  the
    Registrant  shall provide to the  underwriters such documentation (including
    certificates, opinions of counsel and "comfort" letters from auditors) as is
    customary  in  connection  with   underwritten  public  offerings  as   such
    underwriters may reasonably require.
 
        (i)  In connection with any registration effected under this Section 11,
    the parties agree
 
           (i) to indemnify  each other  and the underwriters  in the  customary
       manner,
 
           (ii)  to enter into  an underwriting agreement  in form and substance
       customary for transactions of  such type with the  Manager and the  other
       underwriters participating in such offering, and
 
          (iii)  to take all further actions which shall be reasonably necessary
       to effect such registration and sale  (including if the Manager deems  it
       necessary, participating in road-show presentations).
 
        (j)    The Registrant  shall  be entitled  to  include (at  its expense)
    additional shares of its common stock in a registration effected pursuant to
    this Section 11 only if and to  the extent the Manager determines that  such
    inclusion  will  not  adversely affect  the  prospects for  success  of such
    offering.
 
    12.  ADJUSTMENT UPON CHANGES IN  CAPITALIZATION.  Without limitation to  any
restriction  on  OPTION GRANTOR  contained in  this Agreement  or in  the Merger
Agreement, in the event of any change  in OPTION GRANTOR Common Stock by  reason
of    stock   dividends,   splitups,   mergers    (other   than   the   Merger),
recapitalizations, combinations, exchange of  shares or the  like, the type  and
number  of shares or  securities subject to  the OPTION GRANTOR  Option, and the
purchase price per share provided in Section 1, shall be adjusted  appropriately
to  restore  to  OPTION HOLDER  its  rights  hereunder, including  the  right to
purchase from OPTION GRANTOR (or its successors) shares of OPTION GRANTOR Common
Stock (or such other shares or securities into which OPTION GRANTOR Common Stock
has been so changed)  representing the Option Shares  Percentage of the  Initial
Number of shares of OPTION GRANTOR Common Stock for the aggregate Exercise Price
calculated as of the date of this Agreement as provided in Section 1.
 
                                      G-11
<PAGE>
    13.    RESTRICTIVE LEGENDS.   Each  certificate representing  OPTION GRANTOR
Shares issued to  OPTION HOLDER  hereunder, and  OPTION HOLDER  Shares, if  any,
delivered   to  OPTION  GRANTOR  at  a   Closing,  shall  include  a  legend  in
substantially the following form:
 
    THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN  REGISTERED
    UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES OR
    BLUE  SKY LAWS, AND MAY BE REOFFERED OR SOLD ONLY IF SO REGISTERED OR IF
    AN EXEMPTION FROM  SUCH REGISTRATION IS  AVAILABLE. SUCH SECURITIES  ARE
    ALSO  SUBJECT TO ADDITIONAL RESTRICTIONS ON TRANSFER AS SET FORTH IN THE
    OPTION HOLDER STOCK OPTION  AND TRIGGER PAYMENT  AGREEMENT, DATED AS  OF
    NOVEMBER  10, 1995, A COPY OF WHICH MAY BE OBTAINED FROM THE ISSUER UPON
    REQUEST.
 
It is understood and agreed that:
 
        (i) the reference to the resale  restrictions of the Securities Act  and
    state  securities or Blue Sky  laws in the above  legend shall be removed by
    delivery of  substitute  certificate(s)  without such  reference  if  OPTION
    HOLDER  or OPTION GRANTOR, as  the case may be,  shall have delivered to the
    other party a copy of a letter from  the staff of the SEC, or an opinion  of
    counsel,  in  form and  substance satisfactory  to the  other party,  to the
    effect that such legend is not  required for purposes of the Securities  Act
    or such laws;
 
        (ii)  the reference  to the  provisions to  this Agreement  in the above
    legend shall be  removed by  delivery of  substitute certificate(s)  without
    such  reference if  the shares have  been sold or  transferred in compliance
    with the provisions of  this Agreement and under  circumstances that do  not
    require the retention of such reference; and
 
       (iii)  the legend shall be  removed in its entirety  if the conditions in
    the preceding clauses (i) and (ii) are both satisfied.
 
In addition, such certificates shall bear any other legend as may be required by
law. Certificates  representing  shares sold  in  a registered  public  offering
pursuant  to Section 11  shall not be required  to bear the  legend set forth in
this Section 13.
 
    14.  BINDING EFFECT; NO ASSIGNMENT; NO THIRD PARTY BENEFICIARIES.
 
        (a) This Agreement shall be binding upon and inure to the benefit of the
    parties hereto and their respective successors and permitted assigns.
 
        (b) Except as  expressly provided  for in this  Agreement, neither  this
    Agreement  nor  the  rights  or  obligations  of  either  party  hereto  are
    assignable, except by operation of law,  or with the written consent of  the
    other party.
 
        (c) Nothing contained in this Agreement, express or implied, is intended
    to confer upon any person other than the parties hereto and their respective
    successors  and  permitted  assigns any  rights  or remedies  of  any nature
    whatsoever by reason of this Agreement.
 
        (d) Any  Restricted  Shares sold  by  a  party in  compliance  with  the
    provisions  of Section 11 shall, upon consummation  of such sale, be free of
    the restrictions  imposed with  respect to  such shares  by this  Agreement,
    unless  and  until  such  party shall  repurchase  or  otherwise  become the
    beneficial owner of such shares, and any transferee of such shares shall not
    be entitled to the registration rights of such party.
 
    15.  SPECIFIC PERFORMANCE.  The  parties hereto agree that irreparable  harm
would  occur in the event that any of  the provisions of this Agreement were not
performed in accordance with their  specified terms or were otherwise  breached.
It  is  accordingly agreed  that  the parties  hereto  shall be  entitled  to an
injunction or injunctions to prevent breaches  of this Agreement and to  enforce
specifically  the terms and provisions hereof in  any court of the United States
or any state having jurisdiction, this being in addition to any other remedy  to
which they are entitled at law or equity.
 
                                      G-12
<PAGE>
    16.  VALIDITY.
 
        (a)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement shall  not affect  the  validity or  enforceability of  the  other
    provisions of this Agreement, which shall remain in full force and effect.
 
        (b)  In  the event  any  court or  other  competent authority  holds any
    provisions of this Agreement to be null, void or unenforceable, the  parties
    hereto  shall  negotiate in  good  faith the  execution  and delivery  of an
    amendment to this Agreement in order, as nearly as possible, to  effectuate,
    to  the  extent permitted  by law,  the  intent of  the parties  hereto with
    respect to such provision and the economic effects thereof.
 
        (c) Subject to Section 5, if for any reason any such court or regulatory
    agency determines that OPTION HOLDER is not permitted to acquire, or  OPTION
    GRANTOR  is  not permitted  to repurchase  pursuant to  Section 8,  the full
    number of shares of OPTION GRANTOR Common Stock provided in Section 1 hereof
    (as the same may be adjusted), it is the express intention of OPTION GRANTOR
    to allow OPTION HOLDER to acquire or to require OPTION GRANTOR to repurchase
    such lesser number of shares as may be permissible without any amendment  or
    modification hereof.
 
        (d)  Each  party  agrees  that,  should  any  court  or  other competent
    authority hold any provision  of this Agreement or  part hereof to be  null,
    void  or unenforceable, or  order any party to  take any action inconsistent
    herewith, or not take any action required herein, the other party shall  not
    be  entitled to specific performance of such  provision or part hereof or to
    any other remedy,  including but not  limited to money  damages, for  breach
    hereof  or of any  other provision of  this Agreement or  part hereof as the
    result of such holding or order.
 
    17.  NOTICES.   All notices and other  communications hereunder shall be  in
writing and shall be deemed given if (a) delivered personally, or (b) if sent by
overnight courier service (receipt confirmed in writing), or (c) if delivered by
facsimile  transmission (with receipt  confirmed), or (d)  five days after being
mailed by registered or certified mail (return receipt requested) to the parties
in each case to the following addresses (or at such other address for a party as
shall be specified by like notice):
 
    A.  If to OPTION HOLDER, to:
       IES Industries Inc.
       IES Tower
       200 First Street S.E.
       Cedar Rapids, Iowa 52401
       Attention: Lee Liu
       Fax: (319) 398-4204
       with a copy to:
       Winthrop, Stimson, Putnam & Roberts
       One Battery Park Plaza
       New York, New York 10004-1490
       Attention: Stephen R. Rusmisel, Esq.
       Fax: (212) 858-1500
 
                                      G-13
<PAGE>
    B.  If to OPTION GRANTOR, to:
       Interstate Power Company
       1000 Main Street
       Dubuque, Iowa 52004-0789
       Attention: Wayne H. Stoppelmoor
                 Chairman
       Fax: (319) 557-2202
       with a copy to:
       Milbank, Tweed, Hadley & McCloy
       1 Chase Manhattan Plaza
       New York, New York 10005-1413
       Attention: John T. O'Connor, Esq.
       Fax: (212) 530-5219
 
    18.  GOVERNING LAW.   This Agreement shall be  governed by and construed  in
accordance  with the laws of the State of Delaware applicable to agreements made
and to be performed entirely within such State and without regard to its  choice
of law principles or to any requirement as to jurisdiction or service of process
contained in Section 2708 of Title 6 of the Delaware Code.
 
    19.  INTERPRETATION.
 
        (a)  When reference is  made in this Agreement  to Articles, Sections or
    Exhibits, such reference shall be to an Article, Section or Exhibit of  this
    Agreement, as the case may be, unless otherwise indicated.
 
        (b)  The table of contents and  headings contained in this Agreement are
    for reference  purposes and  shall not  affect  in any  way the  meaning  or
    interpretation of the Agreement.
 
        (c) Whenever the words "include," "includes," or "including" are used in
    this  Agreement, they shall be  deemed to be followed  by the words "without
    limitation."
 
        (d) Whenever "or" is used in this Agreement it shall be construed in the
    nonexclusive sense.
 
    20.  COUNTERPARTS; EFFECT.   This Agreement may be  executed in one or  more
counterparts,  each of which shall be deemed to be an original, but all of which
shall constitute one and the same agreement.
 
    21.   AMENDMENTS; WAIVER.   This  Agreement may  be amended  by the  parties
hereto  and the terms and conditions hereof  may be waived only by an instrument
in writing signed on behalf of each of the parties hereto, or, in the case of  a
waiver, by an instrument signed on behalf of the party waiving compliance.
 
    22.   EXTENSION OF TIME PERIODS.   The time periods for exercises of certain
rights under Sections 2, 7 and 8 shall be extended (but in no event by more than
six months):
 
        (a) to the extent necessary to  obtain all regulatory approvals for  the
    exercise  of such  rights, and for  the expiration of  all statutory waiting
    periods; and
 
        (b) to the extent necessary to  avoid any liability under Section  16(b)
    of the Exchange Act by reason of such exercise.
 
                                      G-14
<PAGE>
    IN  WITNESS WHEREOF,  the parties  hereto have  caused this  Agreement to be
executed by their respective duly authorized officers as of the date first above
written.
 
                                          INTERSTATE POWER COMPANY
 
                                          By: /s/ WAYNE H. STOPPELMOOR
 
                                          --------------------------------------
                                              Name: Wayne H. Stoppelmoor
                                              Title: Chairman of the Board,
                                                     President and Chief
                                                     Executive Officer
 
                                          IES INDUSTRIES INC.
 
                                          By: /s/ LEE LIU
 
                                          --------------------------------------
                                              Name: Lee Liu
                                              Title: Chairman of the Board,
                                                     President and Chief
                                                     Executive Officer
 
                                      G-15
<PAGE>
                                                                         ANNEX H
 
                              EMPLOYMENT AGREEMENT
 
    THIS  AGREEMENT by  and between  Interstate Energy  Corporation, a Wisconsin
corporation (the "Company"),  and Lee  Liu (the  "Executive"), dated  as of  the
           day of           , 199 .
 
    WHEREAS,  WPL  Holdings,  Inc.,  IES  Industries  Inc.  ("IES  Industries"),
Interstate Power  Company,  a Delaware  corporation,  WPLH Acquisition  Co.  and
Interstate  Power Company,  a Wisconsin  corporation (collectively,  the "Merger
Parties"), have  entered  into an  Agreement  and Plan  of  Merger dated  as  of
November 10, 1995, as amended (the "Merger Agreement"); and
 
    WHEREAS,  the Merger Parties  wish to provide for  the orderly succession of
management of the Company following the Effective Time (as defined in the Merger
Agreement); and
 
    WHEREAS, the Merger Parties  further wish to provide  for the employment  by
the  Company of the Executive, and the Executive wishes to serve the Company, in
the capacities and on the terms and conditions set forth in this Agreement:
 
    NOW, THEREFORE, it is hereby agreed as follows:
 
    1.  EMPLOYMENT  PERIOD.   The Company shall  employ the  Executive, and  the
Executive  shall serve the Company as an employee and officer of the Company, on
the terms and conditions set forth in this Agreement, for the period  commencing
on  the Effective Time and  ending on the date  immediately preceding the second
anniversary  of  the  Effective  Time   (the  "Employment  Period").  Upon   the
termination  of the Employment  Period the Executive  will have the  status of a
retired senior executive officer of the Company and shall be entitled to all  of
the rights, privileges and benefits provided to such retired officers.
 
    2.  POSITION AND DUTIES.
 
        (a)   TITLE.  During the Employment Period, the Executive shall serve as
    Chairman  of  the  Board   of  Directors  (the   "Board")  of  the   Company
    ("Chairman"). Upon termination of the Employment Period, the Executive shall
    continue to be eligible to serve as a director of the Company.
 
        (b)   DUTIES.  During the Employment Period, the Executive shall perform
    the normal and ordinary  duties of Chairman and  shall serve, together  with
    the  Vice Chairman of the Board and the Chief Executive Officer, as a member
    of the senior executive team of the Company charged with responsibility  for
    developing  and implementing  programs to achieve  the corporate integration
    and restructuring of  the Merger  Parties following the  Effective Time.  In
    addition, he will have involvement, as appropriate, in government regulatory
    initiatives,  will be involved in  major economic development initiatives of
    the Company and will  serve in such other  capacities and will perform  such
    other  functions consistent with his status as Chairman as may be reasonably
    assigned by the  Board from  time to time.  The Executive  shall devote  the
    necessary time and effort required to perform the above described duties.
 
        (c)   OFFICE.   The  Executive's services  hereunder shall  be performed
    primarily at the  existing executive  offices of IES  Industries located  in
    Cedar  Rapids, Iowa, subject  to such business travel  as shall be necessary
    and appropriate.
 
    3.  COMPENSATION.
 
        (a)  BASE  SALARY.  During  the Employment Period,  the Executive  shall
    receive  an annual base salary ("Annual Base  Salary") of not less than Four
    Hundred  Thousand  Dollars  ($400,000),  payable  in  accordance  with   the
    Company's  regular payroll practice for its  senior executives, as in effect
    from time to  time. During  the Employment  Period, the  Annual Base  Salary
    shall  be reviewed for possible increase  at least annually. Any increase in
    the Annual Base Salary shall not
 
                                      H-1
<PAGE>
    limit or reduce any  other obligation of the  Company under this  Agreement.
    The Annual Base Salary shall not be reduced after any such increase, and the
    term  "Annual Base Salary" shall thereafter  refer to the Annual Base Salary
    as so increased.
 
        (b)    INCENTIVE  COMPENSATION.    During  the  Employment  Period,  the
    Executive  shall participate in such short-term incentive compensation plans
    and long-term incentive compensation plans as  shall be decided upon in  the
    discretion  of the  Compensation Committee  of the  Board (the "Compensation
    Committee")  (the  latter  to  consist  of  plans  offering  stock  options,
    restricted  stock and/or other  long-term incentive compensation), providing
    him with the  opportunity to earn,  on an annualized  basis, short-term  and
    long-term    incentive    compensation    (collectively,    the   "Incentive
    Compensation")  not  less  than  the  aggregate  amount  of  the   incentive
    compensation  that  the  Executive  had an  opportunity  to  earn  under IES
    Industries'  Management  Incentive  Compensation   Plan  (the  "MICP")   and
    Long-Term  Incentive Plan (the "LTIP") in respect of the calendar year ended
    immediately prior to  the Effective  Time, and  such Incentive  Compensation
    shall  be payable in accordance  with standards (I.E., performance criteria,
    performance levels, etc.) which are no less favorable to the Executive  than
    those  applicable  with respect  to  the amounts  that  were payable  to the
    Executive under each of  the MICP and  the LTIP in  respect of the  calendar
    year ended immediately prior to the Effective Time.
 
        (c)   OTHER BENEFITS.  In  addition, and without limiting the generality
    of the  foregoing, during  the  Employment Period  and thereafter:  (A)  the
    Executive  shall  be entitled  to participate  in all  applicable incentive,
    savings and  retirement  plans,  practices, policies  and  programs  of  the
    Company  and its  affiliates to the  same extent as  other senior executives
    (or, where applicable, retired  senior executives) of  the Company, (B)  the
    Executive  and/or  the Executive's  family,  as the  case  may be,  shall be
    eligible for immediate participation in (and without any limitation for pre-
    existing conditions), and shall receive  all benefits under, all  applicable
    welfare  benefit  plans, practices,  policies and  programs provided  by the
    Company  and  its  affiliates,   including,  without  limitation,   medical,
    prescription,  dental, disability, salary  continuance, accidental death and
    travel insurance plans  and programs,  to the  same extent  as other  senior
    executives (or, where applicable, retired senior executives) of the Company,
    provided,  however  that the  Executive's  aggregate benefits  as  a retired
    senior executive under the plans described  in this clause (B) shall not  be
    less  than the  benefits provided  by IES  Industries to  its retired senior
    executive officers as  of the  date of this  Agreement and  (C) the  Company
    shall  maintain, at no cost to the  Executive, life insurance on the life of
    the Executive  payable  to  one  or more  beneficiaries  designated  by  the
    Executive  in  an amount  not less  than  the aggregate  amount of  the life
    insurance provided to the Executive  by IES Industries immediately prior  to
    the Effective Time.
 
        (d)   PERQUISITES.  During the Employment Period, the Executive shall be
    entitled to receive such perquisites as the Company may establish from  time
    to  time which are commensurate with his position and at least comparable to
    those received by other senior executives at the Company.
 
        (e)  EXPENSE REIMBURSEMENT.   The Company shall reimburse the  Executive
    for  all reasonable and documented expenses incurred by the Executive in the
    performance of the Executive's duties under this Agreement.
 
        (f)  SUPPLEMENTAL RETIREMENT BENEFIT.  The Executive and IES  Industries
    have  entered into that certain Amended and Restated Supplemental Retirement
    Agreement dated February 1, 1993,  as amended (the "Supplemental  Retirement
    Agreement").  The Company shall assume, honor and perform the obligations of
    IES Industries under  the Supplemental Retirement  Agreement (as amended  as
    set  forth below). In addition, the Company  and the Executive agree that as
    of the Effective  Time the  terms of the  Supplemental Retirement  Agreement
    shall  be amended as  provided below. (Capitalized terms  used below in this
    Section 3(f) which are not otherwise specifically defined in this  Agreement
    shall  have  the  meanings  ascribed  to  such  terms  in  the  Supplemental
    Retirement  Agreement  as  amended  hereby).  The  Supplemental   Retirement
    Agreement shall be amended as follows:
 
                                      H-2
<PAGE>
           (i)  the  term  "Annual Salary"  as  defined  in Section  2.1  of the
       Supplemental Retirement Agreement for purposes of calculating the benefit
       payable to  the  Executive  and  his  Designated  Beneficiary  under  the
       Supplemental  Retirement  Agreement  shall be  modified  so  that "Annual
       Salary" shall be the  sum of (A) the  Executive's Annual Base Salary  and
       (B) an amount equal to the average of the annual incentive awards payable
       to   the  Executive  under  the  MICP,  or  any  other  annual  incentive
       arrangement of IES Industries or the  Company, in respect of each of  the
       three  (3) consecutive annual performance periods ended immediately prior
       to the termination of the Executive's employment with the Company;
 
           (ii) the Executive shall be fully vested in and entitled to  receive,
       at  Normal  Retirement  Age, the  full  amount of  his  Normal Retirement
       Benefit under the Supplemental  Retirement Agreement, as amended  hereby,
       and  the Executive shall be deemed to have attained Normal Retirement Age
       for all purposes under  the Supplemental Retirement  Agreement as of  the
       date  on which he ceases, for any reason, to receive the compensation and
       benefits set forth in paragraphs  (a), (b) and (c)  of Section 3 of  this
       Agreement;
 
          (iii)  Sections  3.2,  3.3  and  4.1  of  the  Supplemental Retirement
       Agreement  shall  be  amended  to  provide  that  in  the  event  of  the
       Executive's  death  at  any time  on  or  after the  Effective  Time, the
       Executive's Designated  Beneficiary  shall receive  monthly  Supplemental
       Benefit  payments or Death  Benefit payments, as  the case may  be, for a
       period of months that, when added to the number of months, if any, during
       which the  Executive received  monthly  benefits under  the  Supplemental
       Retirement  Agreement, will be equal to  one hundred eighty (180) months;
       and
 
          (iv) for  purposes  of  Section 9.1  of  the  Supplemental  Retirement
       Agreement,  in the event of the Executive's death, the Executive shall be
       treated as  receiving  the Supplemental  Benefit  portion of  the  Normal
       Retirement  Benefit at  the time  of death  regardless of  whether he was
       actually receiving such Supplemental Benefit at such time.
 
    The foregoing  modifications to  the terms  of the  Supplemental  Retirement
Agreement  shall take effect  as of the  Effective Time. As  soon as practicable
following the Effective  Time (but  in no  event later  than 60  days after  the
Effective  Time), the Company and the Executive shall take all actions necessary
to  execute  a  formal  amendment  to  the  Supplemental  Retirement   Agreement
incorporating  the modifications  set forth  above. Until  the time  that such a
formal amendment is properly executed, the provisions of this Section 3(f) shall
serve and be construed,  for all intents  and purposes, as  an amendment to  the
terms  of  the Supplemental  Retirement Agreement,  and  the obligations  of the
Company thereunder shall be governed by the terms of the Supplemental Retirement
Agreement as so amended.
 
    4.  TERMINATION OF EMPLOYMENT.
 
        (a)  DEATH OR  DISABILITY.  The  Executive's employment shall  terminate
    automatically  upon the Executive's death  during the Employment Period. The
    Company shall be entitled to terminate the Executive's employment because of
    the Executive's Disability during the Employment Period. "Disability"  means
    that  (i) the  Executive has been  unable, for  a period of  one hundred and
    eighty (180) consecutive  business days, to  perform the Executive's  duties
    under  this Agreement, as a result of  physical or mental illness or injury,
    and (ii) a physician selected by the Company or its insurers, and acceptable
    to the Executive  or the  Executive's legal  representative, has  determined
    that the Executive's incapacity is total and permanent. A termination of the
    Executive's  employment by the Company  for Disability shall be communicated
    to the Executive by written notice  and shall be effective on the  thirtieth
    (30th)  day after receipt  of such notice by  the Executive (the "Disability
    Effective Date"), unless the Executive  returns to full-time performance  of
    the Executive's duties before the Disability Effective Date.
 
                                      H-3
<PAGE>
        (b)  BY THE COMPANY.
 
           (i)  The Company may terminate  the Executive's employment during the
       Employment Period for Cause or without Cause. "Cause" means:
 
               A.    the  willful  and   continued  failure  of  the   Executive
           substantially  to perform the Executive's duties under this Agreement
           (other than as  a result of  physical or mental  illness or  injury),
           after the Board of Directors of the Company (the "Board") delivers to
           the  Executive  a  written demand  for  substantial  performance that
           specifically identifies the manner in  which the Board believes  that
           the Executive has not substantially performed the Executive's duties;
           or
 
               B.   illegal  conduct or  gross misconduct  by the  Executive, in
           either case that is willful and results in material and  demonstrable
           damage to the business or reputation of the Company.
 
       No act or failure to act on the part of the Executive shall be considered
       "willful"  unless it is done, or omitted  to be done, by the Executive in
       bad faith or  without reasonable  belief that the  Executive's action  or
       omission  was in the best interests of the Company. Any act or failure to
       act that is  based upon  authority given  pursuant to  a resolution  duly
       adopted  by the Board, or the advice of counsel for the Company, shall be
       conclusively presumed to be done, or omitted to be done, by the Executive
       in good faith and in the best interests of the Company.
 
           (ii) A termination of the  Executive's employment for Cause shall  be
       effected  in accordance with the  following procedures. The Company shall
       give the Executive written notice ("Notice of Termination for Cause")  of
       its  intention to terminate the Executive's employment for Cause, setting
       forth in reasonable detail the specific conduct of the Executive that  it
       considers  to  constitute Cause  and  the specific  provision(s)  of this
       Agreement on which it relies, and stating the date, time and place of the
       Board Meeting for Cause. The "Board Meeting for Cause" means a meeting of
       the Board  at  which  the  Executive's  termination  for  Cause  will  be
       considered,  that takes place  not less than  ten (10) and  not more than
       twenty (20)  business days  after the  Executive receives  the Notice  of
       Termination  for  Cause. The  Executive  shall be  given  an opportunity,
       together with counsel, to  be heard at the  Board Meeting for Cause.  The
       Executive's  termination  for  Cause shall  be  effective when  and  if a
       resolution is duly adopted at the Board Meeting for Cause by a two-thirds
       vote of the entire membership of the Board, excluding employee directors,
       stating that in  the good faith  opinion of the  Board, the Executive  is
       guilty  of the conduct described in  the Notice of Termination for Cause,
       and that conduct constitutes Cause under this Agreement.
 
          (iii) A termination of the Executive's employment without Cause  shall
       be  effected  in accordance  with the  following procedures.  The Company
       shall give the Executive written  notice ("Notice of Termination  Without
       Cause")  of its intention to terminate the Executive's employment without
       Cause, stating the  date, time  and place  of the  Board Meeting  without
       Cause.  The "Board Meeting without Cause" means a meeting of the Board at
       which the Executive's termination without Cause will be considered,  that
       takes place not less than ten (10) and not more than twenty (20) business
       days  after  the Executive  receives  the Notice  of  Termination without
       Cause. The  Executive  shall  be  given  an  opportunity,  together  with
       counsel,  to be heard at the Board Meeting without Cause. The Executive's
       termination without Cause shall be effective when and if a resolution  is
       duly  adopted at the Board Meeting without  Cause by a two-thirds vote of
       the entire membership of the Board, excluding employee directors, stating
       that the Executive is terminated without Cause.
 
        (c)  GOOD REASON.
 
           (i) The Executive may terminate employment for Good Reason or without
       Good Reason. "Good Reason" means:
 
                                      H-4
<PAGE>
               A.  the assignment to the Executive of any duties inconsistent in
           any respect  with  paragraphs  (a)  and (b)  of  Section  2  of  this
           Agreement,  or  any other  action by  the Company  that results  in a
           diminution  in  the  Executive's   position,  authority,  duties   or
           responsibilities,   other   than  an   isolated,   insubstantial  and
           inadvertent action that is not taken in bad faith and is remedied  by
           the  Company  promptly  after  receipt  of  notice  thereof  from the
           Executive;
 
               B.  any failure  by the Company to  comply with any provision  of
           Section  3 of this  Agreement, other than  an isolated, insubstantial
           and inadvertent  failure  that it  not  taken  in bad  faith  and  is
           remedied by the Company promptly after receipt of notice thereof from
           the Executive;
 
               C.   any requirement by the Company that the Executive's services
           be rendered  primarily at  a location  or locations  other than  that
           provided for in paragraph (c) of Section 2 of this Agreement.
 
               D.   any purported  termination of the  Executive's employment by
           the Company for a  reason or in a  manner not expressly permitted  by
           this Agreement;
 
               E.   any failure by  the Company to comply  with paragraph (c) of
           Section 12 of this Agreement; or
 
               F.  any other substantial breach of this Agreement by the Company
           that either is  not taken in  good faith  or is not  remedied by  the
           Company promptly after receipt of notice thereof from the Executive.
 
           (ii)  A termination  of employment by  the Executive  for Good Reason
       shall be effectuated  by giving  the Company written  notice ("Notice  of
       Termination for Good Reason") of the termination within six (6) months of
       the  event constituting Good  Reason, setting forth  in reasonable detail
       the specific conduct of the Company that constitutes Good Reason and  the
       specific  provision(s) of this Agreement on which the Executive relies. A
       termination of  employment by  the  Executive for  Good Reason  shall  be
       effective  on the  fifth (5th) business  day following the  date when the
       Notice of Termination for  Good Reason is given,  unless the notice  sets
       forth  a later date (which date shall  in no event be later than (thirty)
       30 days after the notice is given).
 
          (iii) A termination  of the  Executive's employment  by the  Executive
       without  Good  Reason shall  be effected  by  giving the  Company written
       notice of the termination.
 
        (d)  DATE OF TERMINATION.  The  "Date of Termination" means the date  of
    the  Executive's death, the Disability Effective Date, the date on which the
    termination of  the  Executive's employment  by  the Company  for  Cause  or
    without  Cause or by the Executive for Good Reason is effective, or the date
    on which  the  Executive  gives  the Company  notice  of  a  termination  of
    employment without Good Reason, as the case may be.
 
    5.  OBLIGATIONS OF THE COMPANY UPON TERMINATION.
 
        (a)   BY THE COMPANY  OTHER THAN FOR CAUSE,  DEATH OR DISABILITY; BY THE
    EXECUTIVE FOR GOOD REASON.   If, during the  Employment Period, the  Company
    terminates  the  Executive's  employment,  other than  for  Cause,  Death or
    Disability, or  the Executive  terminates employment  for Good  Reason,  the
    Company  shall continue to  provide the Executive  with the compensation and
    benefits set forth in paragraphs (a), (b) and (c) of Section 3 as if he  had
    remained  employed by the Company pursuant to this Agreement through the end
    of the Employment Period and then retired (at which time he will be  treated
    as  eligible for all retiree welfare benefits and other benefits provided to
    retired senior executives, as set forth in Sections 3(c) and (f)); PROVIDED,
    that the  Incentive Compensation  for  such period  shall  be equal  to  the
    maximum  Incentive Compensation that the  Executive would have been eligible
    to earn for such  period; PROVIDED, further that  in lieu of stock  options,
    restricted    stock   and   other    stock-based   awards,   the   Executive
 
                                      H-5
<PAGE>
    shall be paid cash  equal to the  fair market value  (without regard to  any
    restrictions)  of the stock options,  restricted stock and other stock-based
    awards that would otherwise  have been granted;  PROVIDED, further, that  to
    the  extent any benefits described  in paragraph (c) of  Section 3 cannot be
    provided pursuant to  a plan or  program maintained by  the Company for  its
    executives,  the Company  shall provide such  benefits outside  such plan or
    program at no additional cost (including without limitation tax cost) to the
    Executive and his family; and PROVIDED, finally, that during any period when
    the Executive  is eligible  to receive  benefits of  the type  described  in
    clause  (B) of  paragraph (c) of  Section 3  under another employer-provided
    plan, the  benefits provided  by the  Company under  this paragraph  (a)  of
    Section  5 may be made secondary to those provided under such other plan. In
    addition to the foregoing, any restricted  stock outstanding on the Date  of
    Termination  shall be  fully vested  as of the  Date of  Termination and all
    options outstanding on  the Date of  Termination shall be  fully vested  and
    exercisable  and shall remain  in effect and exercisable  through the end of
    their respective terms, without regard to the termination of the Executive's
    employment. The payments  and benefits provided  pursuant to this  paragraph
    (a) of Section 5 are intended as liquidated damages for a termination of the
    Executive's  employment by the Company other than for Cause or Disability or
    for the actions of the Company  leading to a termination of the  Executive's
    employment  by the  Executive for  Good Reason,  and shall  be the  sole and
    exclusive remedy therefor.
 
        (b)  DEATH AND DISABILITY.  If the Executive's employment is  terminated
    by  reason  of the  Executive's death  or  Disability during  the Employment
    Period, the  Company shall  pay to  the Executive  or, in  the case  of  the
    Executive's death, to the Executive's designated beneficiaries (or, if there
    is  no  such beneficiary,  to the  Executive's surviving  spouse, or  if the
    Executive is not survived  by a spouse, to  the Executive's estate or  legal
    representative),  in a lump  sum in cash  within thirty (30)  days after the
    Date of  Termination,  the  sum  of  the  following  amounts  (the  "Accrued
    Obligations"): (1) any portion of the Executive's Annual Base Salary through
    the  Date of Termination that has been earned  but not yet been paid; (2) an
    amount representing the Incentive Compensation for the period that  includes
    the  Date of Termination, computed  by assuming that the  amount of all such
    Incentive Compensation  would  be  equal  to  the  maximum  amount  of  such
    Incentive  Compensation that the Executive would  have been eligible to earn
    for such period, and multiplying that amount by a fraction, the numerator of
    which is the number of days in such period through the Date of  Termination,
    and  the denominator of  which is the  total number of  days in the relevant
    period; (3) any compensation previously deferred by the Executive  (together
    with  any accrued interest or earnings thereon)  that has not yet been paid;
    and (4) any accrued but unpaid Incentive Compensation and vacation pay.  Any
    deferred  compensation  (together  with  any  accrued  interest  or earnings
    thereon, if any) that has not yet been paid, will be paid in accordance with
    the terms and conditions applicable to such deferred compensation.
 
        (c)  BY  THE COMPANY FOR  CAUSE; BY  THE EXECUTIVE OTHER  THAN FOR  GOOD
    REASON.   If  the Executive's  employment is  terminated by  the Company for
    Cause during the Employment Period, the Company shall pay the Executive  the
    Annual  Base Salary through  the Date of  Termination and the  amount of any
    compensation previously deferred by the Executive (together with any accrued
    interest or earnings thereon), in each case to the extent not yet paid,  and
    the  Company shall have no further  obligations under this Agreement, except
    as specified in  Section 6  below. If the  Executive voluntarily  terminates
    employment  during the  Employment Period, other  than for  Good Reason, the
    Company shall pay the Accrued Obligations to the Executive in a lump sum  in
    cash  within thirty (30)  days of the  Date of Termination,  and the Company
    shall have no further obligations under this Agreement, except as  specified
    in Section 6 below.
 
    6.   NON-EXCLUSIVITY OF RIGHTS.  Nothing  in this Agreement shall prevent or
limit the Executive's continuing or  future participation in any plan,  program,
policy  or practice provided by the Company for which the Executive may qualify,
nor shall anything in  this Agreement limit or  otherwise affect such rights  as
the  Executive may have under any contract  or agreement with the Company or any
of its  affiliates  relating to  subject  matter other  than  that  specifically
addressed herein. Vested benefits
 
                                      H-6
<PAGE>
and  other amounts that the Executive is otherwise entitled to receive under the
Incentive Compensation,  the deferred  compensation and  other benefit  programs
listed  in paragraph (c)  of Section 3,  or any other  plan, policy, practice or
program of,  or any  contract  or agreement  with, the  Company  or any  of  its
affiliates  on or after the  Date of Termination shall  be payable in accordance
with the  terms  of each  such  plan,  policy, practice,  program,  contract  or
agreement, as the case may be, except as explicitly modified by this Agreement.
 
    7.  FULL SETTLEMENT.  The Company's obligation to make the payments provided
for in, and otherwise to perform its obligations under, this Agreement shall not
be  affected by any  set-off, counterclaim, recoupment,  defense or other claim,
right or action that the Company may have against the Executive or others. In no
event shall the  Executive be  obligated to seek  other employment  or take  any
other  action by way of mitigation of the amounts payable to the Executive under
any of the  provisions of  this Agreement. The  amounts payable  by the  Company
under  this Agreement shall  not be offset  or reduced by  any amounts otherwise
receivable or received by the Executive from any source, except as  specifically
provided  in paragraph (a)  of Section 5  with respect to  benefits described in
clause (B) of paragraph (c) of Section 3.
 
    8.   CONFIDENTIAL INFORMATION.   The  Executive shall  hold in  a  fiduciary
capacity  for the benefit of the Company all secret or confidential information,
knowledge or data relating to the Company or any of its affiliated companies and
their respective businesses  that the Executive  obtains during the  Executive's
employment  by the Company  or any of  its affiliated companies  and that is not
public knowledge (other  than secret or  confidential information, knowledge  or
data  which becomes public knowledge as a result of the Executive's violation of
this  Section  8)   ("Confidential  Information").  The   Executive  shall   not
communicate,  divulge or disseminate Confidential Information at any time during
or after the  Executive's employment  with the  Company, except  with the  prior
written consent of the Company or as otherwise required by law or legal process.
In  no event shall  any asserted violation  of the provisions  of this Section 8
constitute a basis for deferring or withholding any amounts otherwise payable to
the Executive under this Agreement.
 
    9.  LIMITATION ON PAYMENTS.
 
        (a) Notwithstanding  any  other  provision of  this  Agreement,  if  any
    portion  of any payment  under this Agreement, or  under any other agreement
    with or  plan of  the Company  or its  affiliates (in  the aggregate  "Total
    Payments"),  would constitute an "excess  parachute payment," then the Total
    Payments to be made to the Executive shall be reduced such that the value of
    the aggregate Total Payments that the Executive is entitled to receive shall
    be One Dollar  ($1) less  than the maximum  amount which  the Executive  may
    receive  without becoming subject to the tax imposed by Section 4999 (or any
    successor provision) of the Internal Revenue  Code of 1986, as amended  (the
    "Code") or which the Company may pay without loss of deduction under Section
    280G(a)  of  the Code  (or any  successor provision).  For purposes  of this
    Agreement, the  terms "excess  parachute payment"  and "parachute  payments"
    shall have the meanings assigned to them in Section 280G of the Code (or any
    successor  provision),  and such  "parachute  payments" shall  be  valued as
    provided therein.  Present value  for purposes  of this  Agreement shall  be
    calculated  in  accordance  with  Section 1274(b)(2)  of  the  Code  (or any
    successor provision).  Within  fifteen  (15)  days  following  the  Date  of
    Termination  or notice by  the Company to  the Executive of  its belief that
    there is a  payment or benefit  due the  Executive which will  result in  an
    excess  parachute payment  as defined  in Section 280G  of the  Code (or any
    successor provision),  the  Executive  and the  Company,  at  the  Company's
    expense,  shall  obtain  the  opinion (which  need  not  be  unqualified) of
    nationally recognized  tax counsel  selected  by the  Company's  independent
    auditors  and acceptable to the Executive  in his sole discretion (which may
    be regular outside counsel to the Company), which opinion sets forth (i) the
    amount of the Base Period Income, (ii) the amount and present value of Total
    Payments and (iii)  the amount  and present  value of  any excess  parachute
    payments  determined without regard to the limitations of this paragraph (a)
    of Section 9. As used in this Agreement, the term "Base Period Income" means
    an amount equal to the  Executive's "annualized includible compensation  for
    the    base   period"   as   defined    in   Section   280G(d)(1)   of   the
 
                                      H-7
<PAGE>
    Code (or any successor provision). For  purposes of such opinion, the  value
    of  any  noncash  benefits  or  any deferred  payment  or  benefit  shall be
    determined by  the Company's  independent auditors  in accordance  with  the
    principles  of Sections  280G(d)(3) and  (4) of  the Code  (or any successor
    provisions), which determination shall be evidenced in a certificate of such
    auditors addressed to the Company and  the Executive. Such opinion shall  be
    dated  as of the  Date of Termination  and addressed to  the Company and the
    Executive and shall be binding upon  the Company and the Executive. If  such
    opinion  determines that  there would  be an  excess parachute  payment, any
    payment or benefit  determined by  such counsel  to be  includible in  Total
    Payments  shall be  reduced or eliminated  as specified by  the Executive in
    writing delivered to the Company within  thirty (30) days of his receipt  of
    such  opinion or, if the  Executive fails to so  notify the Company, then as
    the  Company  shall  reasonably  determine,  so  that  under  the  bases  of
    calculations  set forth  in such opinion  there will be  no excess parachute
    payment. If such legal  counsel so requests in  connection with the  opinion
    required  by this paragraph (a) of Section  9, the Executive and the Company
    shall obtain, at the Company's expense, and the legal counsel may rely on in
    providing the  opinion,  the  advice  of  a  firm  of  recognized  executive
    compensation   consultants  as  to   the  reasonableness  of   any  item  of
    compensation to be received by the Executive. If the provisions of  Sections
    280G and 4999 of the Code (or any successor provisions) are repealed without
    succession,  then this  paragraph (a)  of Section 9  shall be  of no further
    force or effect.
 
        (b) If, notwithstanding the provisions of paragraph (a) of Section 9, it
    is ultimately determined by a court or pursuant to a final determination  by
    the  Internal Revenue Service that any  portion of Total Payments is subject
    to the tax (the "Excise  Tax") imposed by Section 4999  of the Code (or  any
    successor  provision), the Company shall pay  to the Executive an additional
    amount (the "Gross-Up  Payment") such that  the net amount  retained by  the
    Executive  after deduction  of any  Excise Tax  and any  interest charges or
    penalties in  respect of  the imposition  of such  Excise Tax  (but not  any
    federal,  state or local income tax) on the Total Payments, and any federal,
    state and local income tax and Excise  Tax upon the payment provided for  by
    this  paragraph (b) of section 9, shall  be equal to the Total Payments. For
    purposes of determining the  amount of the  Gross-Up Payment, the  Executive
    shall  be deemed to pay federal income taxes at the highest marginal rate of
    federal income taxation in the calendar  year in which the Gross-Up  Payment
    is to be made and state and local income taxes at the highest marginal rates
    of taxation in the state and locality of the Executive's domicile for income
    tax  purposes on the date  the Gross-Up Payment is  made, net of the maximum
    reduction in federal income taxes which could be obtained from deduction  of
    such state and local taxes.
 
    10.  EXECUTIVE'S SERVICE ON THE BOARD.
 
        (a)    APPOINTMENT  AND  NOMINATION.    The  Company  shall  appoint the
    Executive as  a member  of the  Board for  an initial  three (3)  year  term
    commencing on the Effective Date (the "Initial Board Term").
 
        (b)    BOARD  AND  COMMITTEE  COMPENSATION.    The  Executive  shall  be
    compensated for his Board services  in accordance with the general  policies
    and  practices of the Company as in effect from time to time relating to the
    compensation of employee and non-employee directors, as the case may be, and
    to  the  extent  that   such  policies  and   practices  provide  for   such
    compensation.
 
        (c)   OFFICE  AND SECRETARIAL ASSISTANCE.   Provided  that the Executive
    remains in the employ of the Company as of the conclusion of the  Employment
    Period  and  continues to  serve as  a  member of  the Board  throughout his
    initial three-year term  as a  director, the  Company shall  provide to  the
    Executive,  for a  period of  one (1) year  following the  conclusion of the
    Employment Period,  a furnished  office  and a  full-time secretary  at  the
    Executive's  disposal at the existing executive offices of IES Industries in
    Cedar Rapids, Iowa for the Executive's use in connection with any continuing
    business of the Company and any personal business of the Executive.
 
    11.   ATTORNEYS' FEES.   The  Company agrees  to pay,  as incurred,  to  the
fullest  extent permitted by law, all legal fees and expenses that the Executive
may reasonably incur as a result of any contest
 
                                      H-8
<PAGE>
(regardless of  the outcome)  by the  Company, the  Executive or  others of  the
validity  or enforceability of  or liability under,  or otherwise involving, any
provision of this Agreement,  together with interest on  any delayed payment  at
the applicable federal rate provided for in Section 7872(f)(2)(A) of the Code.
 
    12.  SUCCESSORS.
 
        (a)  This Agreement is personal to  the Executive and, without the prior
    written consent of the  Company, shall not be  assignable by the  Executive.
    This  Agreement shall  inure to  the benefit  of and  be enforceable  by the
    Executive's legal representatives.
 
        (b) This Agreement shall inure to the benefit of and be binding upon the
    Company and its successors and assigns.
 
        (c) The Company shall require any successor (whether direct or indirect,
    by purchase, merger, consolidation or otherwise) to all or substantially all
    of the business and/or assets of  the Company expressly to assume and  agree
    to perform this Agreement in the same manner and to the same extent that the
    Company  would have been  required to perform  it if no  such succession had
    taken place.  As used  in  this Agreement,  "Company"  shall mean  both  the
    Company  as defined above and any such  successor that assumes and agrees to
    perform this Agreement, by operation of law or otherwise.
 
    13.  MISCELLANEOUS.
 
        (a) This Agreement  shall be  governed by, and  construed in  accordance
    with,  the laws  of the  State of Iowa,  without reference  to principles of
    conflict of  laws.  The captions  of  this Agreement  are  not part  of  the
    provisions  hereof and shall have no force or effect. This Agreement may not
    be amended or modified except by a written agreement executed by the parties
    hereto or their respective successors and legal representatives.
 
        (b) All notices and other  communications under this Agreement shall  be
    in  writing and  shall be given  by hand delivery  to the other  party or by
    facsimile, addressed as follows:
 
        IF TO THE EXECUTIVE:
       Mr. Lee Liu
       [             ]
       IF TO THE COMPANY:
       Interstate Energy Corporation
       222 West Washington Avenue
       P.O. Box 2568
       Madison, Wisconsin 53701-2568
       Attn: General Counsel
 
    or to such other address as either  party furnishes to the other in  writing
    in   accordance  with  this  paragraph  (b)   of  Section  13.  Notices  and
    communications shall be effective when actually received by the addressee.
 
        (c)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement  shall  not affect  the validity  or  enforceability of  any other
    provision of this  Agreement. If any  provision of this  Agreement shall  be
    held  invalid  or  unenforceable  in part,  the  remaining  portion  of such
    provision, together  with  all other  provisions  of this  Agreement,  shall
    remain  valid and enforceable and  continue in full force  and effect to the
    fullest extent consistent with law.
 
        (d) Notwithstanding any other provision  of this Agreement, the  Company
    may  withhold from amounts payable under  this Agreement all federal, state,
    local and foreign taxes that are required to be withheld by applicable  laws
    or regulations.
 
                                      H-9
<PAGE>
        (e)  The  Executive's or  the Company's  failure  to insist  upon strict
    compliance with  any provisions  of,  or to  assert  any right  under,  this
    Agreement  (including,  without limitation,  the right  of the  Executive to
    terminate employment for Good Reason pursuant to paragraph (c) of Section  4
    of  this Agreement) shall not be deemed to  be a waiver of such provision or
    right or of any other provision of or right under this Agreement.
 
        (f) The  Executive  and  the Company  acknowledge  that  this  Agreement
    supersedes   the  Employment  Agreement  between   IES  Industries  and  the
    Executive, dated  February 27,  1991  and the  Executive Change  of  Control
    Severance Agreement between IES Industries and the Executive, dated December
    12,  1989 (and any successor Executive Change of Control Severance Agreement
    between the Executive and IES Industries).
 
        (g) The rights and  benefits of the Executive  under this Agreement  may
    not  be anticipated, alienated or  subject to attachment, garnishment, levy,
    execution or other legal or equitable process except as required by law. Any
    attempt by the  Executive to anticipate,  alienate, assign, sell,  transfer,
    pledge,  encumber or charge the same shall be void. Payments hereunder shall
    not be considered  assets of  the Executive in  the event  of insolvency  or
    bankruptcy.
 
        (h)  This Agreement  may be  executed in  several counterparts,  each of
    which shall be deemed  an original, and  said counterparts shall  constitute
    but one and the same instrument.
 
    14.   EFFECTIVENESS  OF AGREEMENT.   The effectiveness of  this Agreement is
subject to  the  consummation of  the  Combination  (as defined  in  the  Merger
Agreement).  If for any reason the  Combination is not consummated in accordance
with the terms of the Merger Agreement, this Agreement shall be null and void AB
INITIO.
 
    IN WITNESS WHEREOF, the Executive has hereunto set the Executive's hand and,
pursuant to the authorization of the Board of Directors, the Company has  caused
this  Agreement to be executed in its name on  its behalf, all as of the day and
year first above written.
 
                                          INTERSTATE ENERGY CORPORATION
                                          By: ______________________________
 
                                          Name: ____________________________
 
                                          Title: ___________________________
 
                                          __________________________________
                                                       LEE LIU
 
                                      H-10
<PAGE>
                                                                         ANNEX I
 
                              EMPLOYMENT AGREEMENT
 
    THIS  AGREEMENT by  and between  Interstate Energy  Corporation, a Wisconsin
corporation (the "Company"), and Erroll  B. Davis, Jr. (the "Executive"),  dated
as of the           day of          , 199 .
 
                          W I T N E S S E T H  T H A T
 
    WHEREAS, the Company is party to an Agreement and Plan of Merger, as amended
(the "Merger Agreement"), dated November 10, 1995, by and among the Company, IES
Industries  Inc.,  an  Iowa  corporation ("IES"),  Interstate  Power  Company, a
Delaware corporation  ("Interstate Power"),  WPLH Acquisition  Co., a  Wisconsin
corporation  and a wholly-owned subsidiary of  the Company, and Interstate Power
Company, a Wisconsin  corporation and a  wholly-owned subsidiary of  Interstate;
and
 
    WHEREAS, the parties to the Merger Agreement wish to provide for the orderly
succession of management of the Company following the Effective Time (as defined
in the Merger Agreement); and
 
    WHEREAS, the parties to the Merger Agreement further wish to provide for the
employment  by the Company of  the Executive, and the  Executive wishes to serve
the Company  and  its subsidiaries,  in  the capacities  and  on the  terms  and
conditions set forth in this Agreement.
 
    NOW, THEREFORE, it is hereby agreed as follows:
 
    1.   EMPLOYMENT  PERIOD.   The Company shall  employ the  Executive, and the
Executive shall serve the Company, on the terms and conditions set forth in this
Agreement, for  an  initial period  (the  "Initial Period")  commencing  at  the
Effective   Time  and  ending  on  the  date  immediately  preceding  the  fifth
anniversary of the Effective Time. This Agreement thereafter will  automatically
renew  for successive terms of one (1) year each, unless either party hereto has
given sixty (60) days' advance written notice of its or his intent to allow  the
term  of  this Agreement  to  expire. The  term  during which  the  Executive is
employed by  the Company  hereunder (including  without limitation  the  Initial
Period)   is  hereafter  referred  to  as  the  "Employment  Period."  Upon  the
termination of the  Employment Period the  Executive will have  the status of  a
retired  senior executive officer of the Company and shall be entitled to all of
the rights, privileges and benefits provided to such retired officers.
 
    2.  POSITION AND DUTIES.
 
        (a) During the first two (2) years of the Initial Period, the  Executive
    shall  serve as  President and  Chief Executive  Officer of  the Company and
    thereafter, until  the end  of the  Employment Period,  the Executive  shall
    serve  as Chairman of the Board  of Directors, President and Chief Executive
    Officer of the Company; in each  case with such duties and  responsibilities
    as  are customarily  assigned to such  positions, and such  other duties and
    responsibilities not  inconsistent therewith  as may  from time  to time  be
    assigned  to him by the Board of Directors of the Company (the "Board"). The
    Executive also shall continue  to serve as a  member of the Board  following
    the   Effective  Time,  and  the  Board  shall  propose  the  Executive  for
    re-election to the Board throughout the Employment Period.
 
        (b) In addition to the  responsibilities designated in paragraph (a)  of
    Section  2 above, during the three-year period following the Effective Time,
    the Executive shall be entitled to  serve as the Chief Executive Officer  of
    each  entity which during such period is a subsidiary of the Company and the
    Company shall cause the  Executive to be appointed  or elected as the  Chief
    Executive  Officer of  each such  subsidiary. In  his capacity  as the Chief
    Executive Officer of said subsidiaries, the Executive shall have such duties
    and responsibilities as are customarily assigned to such position, and  such
    other  duties and  responsibilities not  inconsistent therewith  as may from
    time
 
                                      I-1
<PAGE>
    to time  be  assigned  to  him  by the  Board  of  Directors  of  each  such
    subsidiary.  During the Employment Period, the Executive also shall serve as
    a member of the Board of Directors of each of the Company's subsidiaries and
    the Company shall cause the Executive to be appointed, elected or re-elected
    as such a director.
 
        (c) During the Employment Period, and excluding any periods of  vacation
    and  sick  leave to  which the  Executive is  entitled, the  Executive shall
    devote reasonable attention  and time  during normal business  hours to  the
    business  and affairs of the  Company and its affiliates  and, to the extent
    necessary to discharge the responsibilities assigned to the Executive  under
    this  Agreement, use  the Executive's reasonable  best efforts  to carry out
    such responsibilities faithfully and efficiently. It shall not be considered
    a violation  of the  foregoing  for the  Executive  to serve  on  corporate,
    industry,  civic  or  charitable  boards  or  committees,  so  long  as such
    activities do  not  significantly  interfere with  the  performance  of  the
    Executive's   responsibilities  as  an  employee  of  the  Company  and  its
    affiliates in accordance with this Agreement.
 
        (d) The Company's  headquarters shall be  located in Madison,  Wisconsin
    and  the Executive shall  reside in the general  area of Madison, Wisconsin.
    During the Employment Period,  the Company also  will provide the  Executive
    with a furnished apartment in the Cedar Rapids, Iowa area.
 
    3.  COMPENSATION.
 
        (a)   BASE SALARY.   The Executive's  compensation during the Employment
    Period shall  be determined  by the  Board upon  the recommendation  of  the
    Compensation and Personnel Committee (or other appropriate committee) of the
    Board,  subject to the next sentence and  paragraph (b) of Section 3. During
    the Employment Period,  the Executive  shall receive an  annual base  salary
    ("Annual  Base Salary")  of not less  than his aggregate  annual base salary
    from the Company and  its subsidiaries as in  effect immediately before  the
    Effective  Time. The Annual Base Salary  shall be payable in accordance with
    the Company's  regular payroll  practice for  its senior  executives, as  in
    effect  from time  to time.  During the  Employment Period,  the Annual Base
    Salary shall  be  reviewed for  possible  increase at  least  annually.  Any
    increase  in the  Annual Base  Salary shall  not limit  or reduce  any other
    obligation of the Company under this Agreement. The Annual Base Salary shall
    not be reduced after  any such increase, and  the term "Annual Base  Salary"
    shall thereafter refer to the Annual Base Salary as so increased.
 
        (b)    INCENTIVE  COMPENSATION.    During  the  Employment  Period,  the
    Executive shall continue to participate in short-term incentive compensation
    plans and long-term incentive compensation  plans (the latter to consist  of
    plans offering stock options, restricted stock and other long-term incentive
    compensation)  offered by the  Company and its  present or future affiliates
    which shall provide  him with  the opportunity  to earn,  on a  year-by-year
    basis,  short-term  and  long-term  incentive  compensation  (the "Incentive
    Compensation") at least equal to the amounts that he had the opportunity  to
    earn  immediately before the Effective Time,  and such compensation shall be
    payable  in   accordance  with   standards  (I.E.,   performance   criteria,
    performance  levels, etc.) which are no less favorable to the Executive than
    those applicable with respect to  the Incentive Compensation payable to  the
    Executive immediately before the Effective Time.
 
        (c)  OTHER BENEFITS.
 
               (i)   RETIREMENT PLAN; SUPPLEMENTAL  RETIREMENT PLAN.  During the
           Employment Period, the  Executive shall participate  in a  retirement
           plan  and/or  supplemental  retirement  plan  (the  "Defined  Benefit
           Arrangement")  such  that  the  aggregate  value  of  the  retirement
           benefits  that  he and  his spouse  will  receive at  the end  of the
           Employment Period under all defined benefit plans of the Company  and
           its  affiliates (whether qualified or not)  will be not less than the
           benefits he would have received (assuming his
 
                                      I-2
<PAGE>
           employment through  the  end  of the  Employment  Period)  under  the
           Wisconsin   Power  and   Light  Company   Retirement  Plan   and  the
           Supplemental Retirement Plan in which the Executive participates,  as
           in effect immediately prior to the Effective Time.
 
               (ii)   EXECUTIVE TENURE COMPENSATION PLAN.  During the Employment
           Period, the Executive shall continue to participate in the  Wisconsin
           Power and Light Company Executive Tenure Compensation Plan.
 
               (iii)  LIFE INSURANCE.  During the Employment Period, the Company
           shall  provide the Executive with  life insurance coverage (the "Life
           Insurance Coverage") providing a death benefit to such beneficiary or
           beneficiaries as the Executive may  designate of not less than  three
           times his Annual Base Salary.
 
               (iv)  ADDITIONAL BENEFITS.  In addition, and without limiting the
           generality  of  the  foregoing,  during  the  Employment  Period  and
           thereafter: (A) the Executive shall be entitled to participate in all
           applicable  incentive,  savings  and  retirement  plans,   practices,
           policies  and programs of the Company  and its affiliates to the same
           extent as  other senior  executives  (or, where  applicable,  retired
           senior  executives) of the Company, and  (B) the Executive and/or the
           Executive's family,  as  the  case  may be,  shall  be  eligible  for
           immediate   participation   in  (and   without  any   limitation  for
           preexisting conditions), and  shall receive all  benefits under,  all
           applicable  welfare benefit  plans, practices,  policies and programs
           provided by  the Company  and its  affiliates, other  than  severance
           plans,  practices,  policies  and  programs  but  including,  without
           limitation,  medical,   prescription,  dental,   disability,   salary
           continuance,   employee   life  insurance,   group   life  insurance,
           accidental death and travel accident insurance plans and programs, to
           the same extent  as other  senior executives  (or, where  applicable,
           retired  senior executives)  of the Company,  provided, however, that
           the Executive's  aggregate benefits  as  a retired  senior  executive
           under  the plans described in this clause  (B) shall not be less than
           the benefits  provided  by the  Company  and its  affiliates  to  its
           retired senior executive officers as of the date of this Agreement.
 
        (d)   PERQUISITES.  During the Employment Period, the Executive shall be
    entitled to receive such perquisites as the Company may establish from  time
    to  time which are commensurate with his position and at lease comparable to
    those received by other senior executives at the Company.
 
        (e)  EXPENSE REIMBURSEMENT.   The Company shall reimburse the  Executive
    for  all reasonable and documented expenses incurred by the Executive in the
    performance of the Executive's duties under this Agreement.
 
    4.  TERMINATION OF EMPLOYMENT.
 
        (a)  DEATH OR  DISABILITY.  The  Executive's employment shall  terminate
    automatically  upon the Executive's death  during the Employment Period. The
    Company shall be entitled to terminate the Executive's employment because of
    the Executive's Disability during the Employment Period. "Disability"  means
    that  (i) the  Executive has  been unable, for  a period  of 180 consecutive
    business days, to perform the Executive's duties under this Agreement, as  a
    result  of  physical  or mental  illness  or  injury, and  (ii)  a physician
    selected by the Company or its insurers, and acceptable to the Executive  or
    the  Executive's legal  representative, has determined  that the Executive's
    incapacity  is  total  and  permanent.  A  termination  of  the  Executive's
    employment  by  the  Company for  Disability  shall be  communicated  to the
    Executive by written notice,  and shall be effective  on the 30th day  after
    receipt  of such notice by the  Executive (the "Disability Effective Date"),
    unless the Executive  returns to  full-time performance  of the  Executive's
    duties before the Disability Effective Date.
 
                                      I-3
<PAGE>
        (b)  BY THE COMPANY.
 
           (i)  The Company may terminate  the Executive's employment during the
       Employment Period for Cause or without Cause. "Cause" means:
 
               A.    the  willful  and   continued  failure  of  the   Executive
           substantially  to perform the Executive's duties under this Agreement
           (other than as  a result of  physical or mental  illness or  injury),
           after  the  Board  delivers to  the  Executive a  written  demand for
           substantial performance that  specifically identifies  the manner  in
           which  the Board  believes that  the Executive  has not substantially
           performed the Executive's duties; or
 
               B.   illegal conduct  or gross  misconduct by  the Executive,  in
           either  case that is willful and results in material and demonstrable
           damage to the business or reputation of the Company.
 
       No act or failure to act on the part of the Executive shall be considered
       "willful" unless it is done, or omitted  to be done, by the Executive  in
       bad  faith or  without reasonable belief  that the  Executive's action or
       omission was in the best interests of the Company. Any act or failure  to
       act  that is  based upon  authority given  pursuant to  a resolution duly
       adopted by the Board, or the advice of counsel for the Company, shall  be
       conclusively presumed to be done, or omitted to be done, by the Executive
       in good faith and in the best interests of the Company.
 
           (ii)  A termination of the Executive's  employment for Cause shall be
       effected in accordance with the  following procedures. The Company  shall
       give  the Executive written notice ("Notice of Termination for Cause") of
       its intention to terminate the Executive's employment for Cause,  setting
       forth  in reasonable detail the specific conduct of the Executive that it
       considers to  constitute  Cause and  the  specific provision(s)  of  this
       Agreement on which it relies, and stating the date, time and place of the
       Special  Board Meeting for  Cause. The "Special  Board Meeting for Cause"
       means a meeting of the Board called and held specifically for the purpose
       of considering the  Executive's termination for  Cause, that takes  place
       not  less than ten (10) and not more than twenty (20) business days after
       the Executive receives the Notice of Termination for Cause. The Executive
       shall be given an opportunity, together with counsel, to be heard at  the
       Special  Board Meeting for  Cause. The Executive's  termination for Cause
       shall be  effective when  and if  a  resolution is  duly adopted  at  the
       Special  Board  Meeting for  Cause  by a  two-thirds  vote of  the entire
       membership of the  Board, excluding employee  directors, stating that  in
       the  good faith  opinion of  the Board,  the Executive  is guilty  of the
       conduct described  in  the Notice  of  Termination for  Cause,  and  that
       conduct constitutes Cause under this Agreement.
 
          (iii)  A termination of the Executive's employment without Cause shall
       be effected  in accordance  with the  following procedures.  The  Company
       shall  give the Executive written  notice ("Notice of Termination without
       Cause") of its intention to terminate the Executive's employment  without
       Cause,  stating the  date, time  and place  of the  Special Board Meeting
       without Cause. The "Special Board Meeting without Cause" means a  meeting
       of  the Board called and held specifically for the purpose of considering
       the Executive's termination  with-out Cause,  that takes  place not  less
       than  ten (10)  and not  more than  twenty (20)  business days  after the
       Executive receives the Notice of Termination without Cause. The Executive
       shall be given an opportunity, together with counsel, to be heard at  the
       Special  Board Meeting without Cause. The Executive's termination without
       Cause shall be effective when and if a resolution is duly adopted at  the
       Special  Board Meeting without  Cause by a two-thirds  vote of the entire
       membership of the Board, excluding  employee directors, stating that  the
       Executive is terminated without Cause.
 
                                      I-4
<PAGE>
        (c)  GOOD REASON.
 
           (i) The Executive may terminate employment for Good Reason or without
       Good Reason. "Good Reason" means:
 
               A.  the assignment to the Executive of any duties inconsistent in
           any  respect  with  paragraphs  (a)  and (b)  of  Section  2  of this
           Agreement, or  any other  action by  the Company  that results  in  a
           diminution   in  the  Executive's   position,  authority,  duties  or
           responsibilities,  other   than   an  isolated,   insubstantial   and
           inadvertent  action that is not taken in bad faith and is remedied by
           the Company  promptly  after  receipt  of  notice  thereof  from  the
           Executive;
 
               B.   any failure by  the Company to comply  with any provision of
           Section 3 of  this Agreement, other  than an isolated,  insubstantial
           and  inadvertent  failure  that is  not  taken  in bad  faith  and is
           remedied by the Company promptly after receipt of notice thereof from
           the Executive;
 
               C.  any requirement by the Company that the Executive's  services
           be  rendered primarily  at a  location or  locations other  than that
           provided for in paragraph (d) of Section 2 of this Agreement;
 
               D.  any  purported termination of  the Executive's employment  by
           the  Company for a reason  or in a manner  not expressly permitted by
           this Agreement;
 
               E.  any failure  by the Company to  comply with paragraph (c)  of
           Section 11 of this Agreement; or
 
               F.  any other substantial breach of this Agreement by the Company
           that  either is  not taken in  good faith  or is not  remedied by the
           Company promptly after receipt of notice thereof from the Executive.
 
           (ii) A termination  of employment  by the Executive  for Good  Reason
       shall  be effectuated  by giving the  Company written  notice ("Notice of
       Termination for Good Reason") of the termination within six months of the
       event constituting Good  Reason, setting forth  in reasonable detail  the
       specific  conduct of  the Company  that constitutes  Good Reason  and the
       specific provision(s) of this Agreement on which the Executive relies.  A
       termination  of  employment by  the Executive  for  Good Reason  shall be
       effective on the fifth business day following the date when the Notice of
       Termination for Good  Reason is  given, unless  the notice  sets forth  a
       later  date (which date shall in no  event be later than thirty (30) days
       after the notice is given).
 
          (iii) A termination  of the  Executive's employment  by the  Executive
       without  Good  Reason shall  be effected  by  giving the  Company written
       notice of the termination.
 
        (d)  DATE OF TERMINATION.  The  "Date of Termination" means the date  of
    the  Executive's death, the Disability Effective Date, the date on which the
    termination of  the  Executive's employment  by  the Company  for  Cause  or
    without  Cause or by the Executive for Good Reason is effective, or the date
    on which  the  Executive  gives  the Company  notice  of  a  termination  of
    employment without Good Reason, as the case may be.
 
    5.  OBLIGATIONS OF THE COMPANY UPON TERMINATION.
 
        (a)   BY THE COMPANY  OTHER THAN FOR CAUSE,  DEATH OR DISABILITY; BY THE
    EXECUTIVE FOR GOOD REASON.   If, during the  Employment Period, the  Company
    terminates  the  Executive's employment,  other  than for  Cause,  Death, or
    Disability, or  the Executive  terminates employment  for Good  Reason,  the
    Company  shall continue to  provide the Executive  with the compensation and
    benefits set forth in paragraphs (a), (b) and (c) of Section 3 as if he  had
    remained  employed by the Company pursuant to this Agreement through the end
    of the Employment Period and then retired (at which time he will be  treated
    as   eligible   for   and  will   be   entitled  to   receive   all  retiree
 
                                      I-5
<PAGE>
    welfare benefits and other benefits  provided to retired senior  executives,
    as  set forth in Section 3(c), with  such benefits being calculated for this
    purpose as though the Executive  had retired at age  62 with earnings on  an
    annual  basis during the  years between the  Date of Termination  and age 62
    equal to the  Executive's earnings  for the year  immediately preceding  the
    Date  of  Termination); provided,  that the  Incentive Compensation  for the
    period through  the end  of the  Employment  Period shall  be equal  to  the
    maximum  Incentive Compensation that the  Executive would have been eligible
    to earn for such  period; provided, further that  in lieu of stock  options,
    restricted  stock and other stock-based awards,  the Executive shall be paid
    cash equal to the fair market value (without regard to any restrictions)  of
    the  stock options, restricted stock and other stock-based awards that would
    otherwise have been granted;  and provided, further that  to the extent  any
    benefits described in paragraph (c) of Section 3 cannot be provided pursuant
    to  the plan or  program maintained by  the Company for  its executives, the
    Company shall  provide such  benefits outside  such plan  or program  at  no
    additional cost (including without limitation tax cost) to the Executive and
    his family; and provided, finally, that during any period when the Executive
    is  eligible to  receive benefits  of the  type described  in clause  (B) of
    paragraph (c)(iv) of  Section 3  under another  employer-provided plan,  the
    benefits  provided by the Company under this  paragraph (a) of Section 5 may
    be made secondary to  those provided under such  other plan. In addition  to
    the  foregoing, any restricted stock outstanding  on the Date of Termination
    shall be  fully  vested  as of  the  Date  of Termination  and  all  options
    outstanding on the Date of Termination shall be fully vested and exercisable
    and  shall  remain  in  effect  and exercisable  through  the  end  of their
    respective terms,  without  regard to  the  termination of  the  Executive's
    employment.  The payments and  benefits provided pursuant  to this paragraph
    (a) of Section 5 are intended as liquidated damages for a termination of the
    Executive's employment by the Company other than for Cause or Disability  or
    for  the actions of the Company leading  to a termination of the Executive's
    employment by  the Executive  for Good  Reason, and  shall be  the sole  and
    exclusive remedy therefor.
 
        (b)   DEATH AND DISABILITY.  If the Executive's employment is terminated
    by reason  of the  Executive's  death or  Disability during  the  Employment
    Period,  the  Company shall  pay to  the Executive  or, in  the case  of the
    Executive's death, to the Executive's designated beneficiaries (or, if there
    is no such beneficiary, to the Executive's estate or legal  representative),
    in a lump sum in cash within thirty (30) days after the Date of Termination,
    the  sum  of  the following  amounts  (the "Accrued  Obligations"):  (1) any
    portion  of  the  Executive's  Annual  Base  Salary  through  the  Date   of
    Termination  that  has not  yet been  paid; (2)  an amount  representing the
    Incentive Compensation for the period that includes the Date of Termination,
    computed by  assuming that  the amount  of all  such Incentive  Compensation
    would be equal to the maximum amount of such Incentive Compensation that the
    Executive  would have been eligible to earn for such period, and multiplying
    that amount by a fraction, the numerator  of which is the number of days  in
    such period through the Date of Termination, and the denominator of which is
    the  total  number of  days  in the  relevant  period; (3)  any compensation
    previously deferred by the Executive (together with any accrued interest  or
    earnings thereon) that has not yet been paid; and (4) any accrued but unpaid
    Incentive Compensation and vacation pay. Any deferred compensation (together
    with any accrued interest or earnings thereon, if any) that has not yet been
    paid, will be paid in accordance with the terms and conditions applicable to
    such deferred compensation.
 
        (c)   BY  THE COMPANY FOR  CAUSE; BY  THE EXECUTIVE OTHER  THAN FOR GOOD
    REASON.  If  the Executive's  employment is  terminated by  the Company  for
    Cause  during the Employment Period, the Company shall pay the Executive the
    Annual Base Salary  through the Date  of Termination and  the amount of  any
    compensation previously deferred by the Executive (together with any accrued
    interest  or earnings thereon), in each case to the extent not yet paid, and
    the Company shall have no  further obligations under this Agreement,  except
    as  specified in  Section 6 below.  If the  Executive voluntarily terminates
    employment during the Employment Period, other than for
 
                                      I-6
<PAGE>
    Good Reason, the Company shall pay the Accrued Obligations to the  Executive
    in  a lump sum in  cash within thirty (30) days  of the Date of Termination,
    and the  Company shall  have no  further obligations  under this  Agreement,
    except as specified in Section 6 below.
 
    6.   NON-EXCLUSIVITY OF RIGHTS.  Nothing  in this Agreement shall prevent or
limit the Executive's continuing or  future participation in any plan,  program,
policy  or practice provided by  the Company or any  of its affiliates for which
the Executive  may  qualify, nor  shall  anything  in this  Agreement  limit  or
otherwise  affect such rights  as the Executive  may have under  any contract or
agreement with the Company or any  of its affiliates relating to subject  matter
other than that specifically addressed herein. Vested benefits and other amounts
that  the  Executive  is  otherwise  entitled  to  receive  under  the Incentive
Compensation program,  the  Defined  Benefit  Arrangement,  the  Life  Insurance
Coverage,  the  Executive  Tenure Compensation  Plan,  the  Executive's Deferred
Compensation Plan(s), or any other plan, policy, practice or program of, or  any
contract or agreement with, the Company or any of its affiliates on or after the
Date  of Termination shall be payable in  accordance with the terms of each such
plan, policy, practice,  program, contract  or agreement,  as the  case may  be,
except as explicitly modified by this Agreement.
 
    7.  FULL SETTLEMENT.  The Company's obligation to make the payments provided
for in, and otherwise to perform its obligations under, this Agreement shall not
be  affected by any  set-off, counterclaim, recoupment,  defense or other claim,
right or action that the Company may have against the Executive or others. In no
event shall the  Executive be  obligated to seek  other employment  or take  any
other  action by way of mitigation of the amounts payable to the Executive under
any of the  provisions of  this Agreement. The  amounts payable  by the  Company
under  this Agreement shall  not be offset  or reduced by  any amounts otherwise
receivable or received by the Executive from any source, except as  specifically
provided  in paragraph (a)  of Section 5  with respect to  benefits described in
clause (B) of paragraph (c)(iv) of Section 3.
 
    8.   CONFIDENTIAL INFORMATION.   The  Executive shall  hold in  a  fiduciary
capacity  for the benefit of the Company all secret or confidential information,
knowledge or data relating to the Company or any of its affiliated companies and
their respective businesses  that the Executive  obtains during the  Executive's
employment  by the Company  or any of  its affiliated companies  and that is not
public knowledge (other than  as a result of  the Executive's violation of  this
Section  8) ("Confidential  Information"). The Executive  shall not communicate,
divulge or disseminate Confidential Information at any time during or after  the
Executive's  employment with the Company, except  with the prior written consent
of the Company or  as otherwise required  by law or legal  process. In no  event
shall  any asserted violation of  the provisions of this  Section 8 constitute a
basis for  deferring  or  withholding  any  amounts  otherwise  payable  to  the
Executive under this Agreement.
 
    9.  LIMITATION ON PAYMENTS.
 
        (a)  Notwithstanding  any  other  provision of  this  Agreement,  if any
    portion of any payment  under this Agreement, or  under any other  agreement
    with  or plan  of the  Company or  its affiliates  (in the  aggregate "Total
    Payments"), would constitute an "excess  parachute payment," then the  Total
    Payments to be made to the Executive shall be reduced such that the value of
    the aggregate Total Payments that the Executive is entitled to receive shall
    be  One Dollar  ($1) less  than the maximum  amount which  the Executive may
    receive without becoming subject to the tax imposed by Section 4999 (or  any
    successor  provision) of the Internal Revenue  Code of 1986, as amended (the
    "Code") or which the Company may pay without loss of deduction under Section
    280G(a) of  the Code  (or any  successor provision).  For purposes  of  this
    Agreement,  the terms  "excess parachute  payment" and  "parachute payments"
    shall have the meanings assigned to them in Section 280G of the Code (or any
    successor provision),  and  such "parachute  payments"  shall be  valued  as
    provided  therein. Present  value for  purposes of  this Agreement  shall be
    calculated in  accordance  with  Section  1274(b)(2) of  the  Code  (or  any
    successor  provision).  Within  fifteen  (15)  days  following  the  Date of
    Termination or notice  by the Company  to the Executive  of its belief  that
    there  is a  payment or benefit  due the  Executive which will  result in an
    excess parachute
 
                                      I-7
<PAGE>
    payment as defined in Section 280G of the Code (or any successor provision),
    the Executive and the  Company, at the Company's  expense, shall obtain  the
    opinion (which need not be unqualified) of nationally recognized tax counsel
    selected  by  the  Company's  independent  auditors  and  acceptable  to the
    Executive in his sole  discretion (which may be  regular outside counsel  to
    the  Company), which opinion  sets forth (i)  the amount of  the Base Period
    Income, (ii) the amount  and present value of  Total Payments and (iii)  the
    amount and present value of any excess parachute payments determined without
    regard  to the limitations  of this paragraph  (a) of Section  9. As used in
    this Agreement, the term "Base Period  Income" means an amount equal to  the
    Executive's  "annualized  includible compensation  for  the base  period" as
    defined in Section 280G(d)(1) of the Code (or any successor provision).  For
    purposes  of such opinion, the value of any noncash benefits or any deferred
    payment or benefit shall be determined by the Company's independent auditors
    in accordance with the principles of Sections 280G(d)(3) and (4) of the Code
    (or any successor provisions), which  determination shall be evidenced in  a
    certificate  of such  auditors addressed to  the Company  and the Executive.
    Such opinion shall be dated as of  the Date of Termination and addressed  to
    the  Company and the Executive and shall be binding upon the Company and the
    Executive. If  such  opinion  determines  that  there  would  be  an  excess
    parachute  payment, any payment or benefit  determined by such counsel to be
    includible in Total Payments shall be reduced or eliminated as specified  by
    the Executive in writing delivered to the Company within thirty (30) days of
    his  receipt of  such opinion or,  if the  Executive fails to  so notify the
    Company, then as the Company shall  reasonably determine, so that under  the
    bases  of calculations  set forth  in such opinion  there will  be no excess
    parachute payment. If such legal counsel so requests in connection with  the
    opinion  required by this paragraph (a) of  Section 9, the Executive and the
    Company shall obtain, at  the Company's expense, and  the legal counsel  may
    rely  on  in providing  the  opinion, the  advice  of a  firm  of recognized
    executive compensation consultants as to  the reasonableness of any item  of
    compensation  to be received by the Executive. If the provisions of Sections
    280G and 4999 of the Code (or any successor provisions) are repealed without
    succession, then this  paragraph (a)  of Section 9  shall be  of no  further
    force or effect.
 
        (b) If, notwithstanding the provisions of paragraph (a) of Section 9, it
    is  ultimately determined by a court or pursuant to a final determination by
    the Internal Revenue Service that any  portion of Total Payments is  subject
    to  the tax (the "Excise  Tax") imposed by Section 4999  of the Code (or any
    successor provision), the Company shall  pay to the Executive an  additional
    amount  (the "Gross-Up  Payment") such that  the net amount  retained by the
    Executive after deduction  of any  Excise Tax  and any  interest charges  or
    penalties  in respect  of the  imposition of  such Excise  Tax (but  not any
    federal, state or local income tax) on the Total Payments, and any  federal,
    state  and local income tax and Excise  Tax upon the payment provided for by
    this paragraph (b) of Section 9, shall  be equal to the Total Payments.  For
    purposes  of determining the  amount of the  Gross-Up Payment, the Executive
    shall be deemed to pay federal income taxes at the highest marginal rate  of
    federal  income taxation in the calendar  year in which the Gross-Up Payment
    is to be made and state and local income taxes at the highest marginal rates
    of taxation in the state and locality of the Executive's domicile for income
    tax purposes on the date  the Gross-Up Payment is  made, net of the  maximum
    reduction  in federal income taxes which could be obtained from deduction of
    such state and local taxes.
 
    10.   ATTORNEYS' FEES.   The  Company agrees  to pay,  as incurred,  to  the
fullest  extent permitted by law, all legal fees and expenses that the Executive
may reasonably incur as a result of  any contest (regardless of the outcome)  by
the  Company, the Executive  or others of  the validity or  enforceability of or
liability under,  or  otherwise  involving, any  provision  of  this  Agreement,
together  with interest  on any delayed  payment at the  applicable federal rate
provided for in Section 7872(f)(2)(A) of the Code.
 
    11.  SUCCESSORS.
 
        (a) This Agreement is personal to  the Executive and, without the  prior
    written  consent of the  Company, shall not be  assignable by the Executive.
    This Agreement  shall inure  to the  benefit of  and be  enforceable by  the
    Executive's legal representatives.
 
                                      I-8
<PAGE>
        (b) This Agreement shall inure to the benefit of and be binding upon the
    Company and its successors and assigns.
 
        (c) The Company shall require any successor (whether direct or indirect,
    by purchase, merger, consolidation or otherwise) to all or substantially all
    of  the business and/or assets of the  Company expressly to assume and agree
    to perform this Agreement in the same manner and to the same extent that the
    Company would have  been required to  perform it if  no such succession  had
    taken  place.  As used  in  this Agreement,  "Company"  shall mean  both the
    Company as defined above and any  such successor that assumes and agrees  to
    perform this Agreement, by operation of law or otherwise.
 
    12.  MISCELLANEOUS.
 
        (a)  This Agreement  shall be governed  by, and  construed in accordance
    with, the laws of the State of Wisconsin, without reference to principles of
    conflict of  laws.  The captions  of  this Agreement  are  not part  of  the
    provisions  hereof and shall have no force or effect. This Agreement may not
    be amended or modified except by a written agreement executed by the parties
    hereto or their respective successors and legal representatives.
 
        (b) All notices and other  communications under this Agreement shall  be
    in  writing and  shall be given  by hand delivery  to the other  party or by
    registered or  certified mail,  return receipt  requested, postage  prepaid,
    addressed as follows:
 
           If to the Executive:
 
           Erroll B. Davis, Jr.
 
           If to the Company:
 
           Interstate Energy Corporation
           222 West Washington Avenue
           P.O. Box 2568
           Madison, Wisconsin 53701-2568
           Attention: General Counsel
 
           With a copy to:
 
           Benjamin F. Garmer, III
           c/o Foley & Lardner
           777 East Wisconsin Avenue
           Milwaukee, WI 53202-5367
 
    or  to such other address as either  party furnishes to the other in writing
    in  accordance  with  this  paragraph   (b)  of  Section  12.  Notices   and
    communications shall be effective when actually received by the addressee.
 
        (c)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement shall  not affect  the  validity or  enforceability of  any  other
    provision  of this  Agreement. If any  provision of this  Agreement shall be
    held invalid  or  unenforceable  in  part, the  remaining  portion  of  such
    provision,  together  with all  other  provisions of  this  Agreement, shall
    remain valid and enforceable  and continue in full  force and effect to  the
    fullest extent consistent with law.
 
                                      I-9
<PAGE>
        (d)  Notwithstanding any other provisions of this Agreement, the Company
    may withhold from amounts payable  under this Agreement all federal,  state,
    local  and foreign taxes that are required to be withheld by applicable laws
    or regulations.
 
        (e) The  Executive's or  the  Company's failure  to insist  upon  strict
    compliance  with  any provisions  of,  or to  assert  any right  under, this
    Agreement  (including,  without  limitation,  the  right  of  Executive   to
    terminate  employment for Good Reason pursuant to paragraph (c) of Section 4
    of this Agreement) shall not be deemed  to be a waiver of such provision  or
    right or of any other provision of or right under this Agreement.
 
        (f)  The  Executive  and  the Company  acknowledge  that  this Agreement
    supersedes any other  agreement between them  concerning the subject  matter
    hereof,  excluding the agreement between the Executive and the Company dated
    June 25, 1994, as in effect on the date hereof or as hereafter amended  from
    time  to time  (the "Severance Agreement");  PROVIDED, HOWEVER,  that to the
    extent that a  payment or  benefit to be  provided under  this Agreement  is
    similarly  to be provided under the  Severance Agreement, the Company agrees
    to pay or provide  to the Executive that  payment or benefit which  provides
    the  highest value to the  Executive, and the Executive  agrees, in order to
    avoid duplication of payments or benefits, that upon the receipt of any such
    highest value  payment  or  benefit  under  either  this  Agreement  or  the
    Severance  Agreement, as  the case  may be,  he shall  have no  right to any
    similar payment or benefit of lesser value under the other agreement.
 
        (g) The rights and  benefits of the Executive  under this Agreement  may
    not   be  anticipated,   assigned,  alienated  or   subject  to  attachment,
    garnishment, levy, execution or other  legal or equitable process except  as
    required  by  law. Any  attempt by  the  Executive to  anticipate, alienate,
    assign, sell, transfer, pledge, encumber or  charge the same shall be  void.
    Payments  hereunder shall not  be considered assets of  the Executive in the
    event of insolvency or bankruptcy.
 
        (h) This  Agreement may  be executed  in several  counterparts, each  of
    which  shall be deemed  an original, and  said counterparts shall constitute
    but one and the same instrument.
 
    13.  EFFECTIVENESS  OF AGREEMENT.   The effectiveness of  this Agreement  is
subject  to the consummation of the Merger (as defined in the Merger Agreement).
If for any  reason the  Combination is not  consummated in  accordance with  the
terms of the Merger Agreement, this Agreement shall be null and void, AB INITIO.
 
    IN WITNESS WHEREOF, the Executive has hereunto set the Executive's hand and,
pursuant to the authorization of its Board of Directors, the Company has caused
this Agreement to be executed in its name and on its behalf, all as of the day
and year first above written.
 
                                          --------------------------------------
                                          Erroll B. Davis, Jr.
 
                                          INTERSTATE ENERGY CORPORATION
 
                                          By
                                          --------------------------------------
 
                                      I-10
<PAGE>
                                                                         ANNEX J
 
                              EMPLOYMENT AGREEMENT
 
    THIS  AGREEMENT by  and between  Interstate Energy  Corporation, a Wisconsin
corporation (the "Company"), and Wayne  Stoppelmoor (the "Executive"), dated  as
of the            day of           , 199 .
 
    WHEREAS,  WPL Holdings, Inc., IES Industries Inc., Interstate Power Company,
a Delaware corporation ("Interstate Power"), WPLH Acquisition Co. and Interstate
Power Company,  a Wisconsin  corporation (collectively,  the "Merger  Parties"),
have entered into an Agreement and Plan of Merger dated as of November 10, 1995,
as amended (the "Merger Agreement"); and
 
    WHEREAS,  the Merger Parties  wish to provide for  the orderly succession of
management of the Company following the Effective Time (as defined in the Merger
Agreement); and
 
    WHEREAS, the Merger Parties  further wish to provide  for the employment  by
the  Company of the Executive, and the Executive wishes to serve the Company, in
the capacities and on the terms and conditions set forth in this Agreement:
 
    NOW, THEREFORE, it is hereby agreed as follows:
 
    1.  EMPLOYMENT PERIOD/CONSULTING PERIOD.
 
        (a) The  Company shall  employ the  Executive, and  the Executive  shall
    serve  the Company as an  employee and officer of  the Company, on the terms
    and conditions set forth in this Agreement, for the period commencing on the
    Effective Time  and ending  on  the date  immediately preceding  the  second
    anniversary  of  the  Effective  Time (the  "Employment  Period").  Upon the
    termination of the Employment Period the Executive will have the status of a
    retired senior executive officer of the Company and shall be entitled to all
    of the rights, privileges and benefits provided to such retired officers.
 
        (b) In addition  to his  status as a  retiree, for  the one-year  period
    immediately  following the  Employment Period (the  "Consulting Period") the
    Executive shall act as a consultant  to the Company as more fully  described
    in Section 2(d) below.
 
    2.  POSITION AND DUTIES.
 
        (a)   TITLE.  During the Employment Period, the Executive shall serve as
    Vice Chairman of the Board of Directors (the "Board") of the Company  ("Vice
    Chairman").  Upon the  termination of  the Employment  Period, the Executive
    shall continue to be eligible to serve as a director of the Company.
 
        (b)  DUTIES.  During the Employment Period, the Executive shall  perform
    the  normal and ordinary  duties of Vice Chairman  and shall serve, together
    with the Chairman  of the  Board (the  "Chairman") and  the Chief  Executive
    Officer,  as a member  of the senior  executive team of  the Company charged
    with responsibility for developing and implementing programs to achieve  the
    corporate  integration and restructuring of the Merger Parties following the
    Effective Time. In addition, he will serve in such other capacities and will
    perform such other functions consistent with his status as Vice Chairman  as
    may  be reasonably assigned  by the Board  from time to  time. The Executive
    shall devote the  necessary time and  effort required to  perform the  above
    described duties and shall report to the Board.
 
        (c)   OFFICE.   The  Executive's services  hereunder shall  be performed
    primarily at the executive offices of the Company located in Dubuque,  Iowa,
    subject to such business travel as shall be necessary and appropriate.
 
        (d)  CONSULTANCY.  During the Consulting Period, (i) the Executive shall
    serve  as  a  consultant to  the  Chief Executive  Officer,  performing such
    consulting services (but not in excess of forty
 
                                      J-1
<PAGE>
    (40) hours  in any  month) as  the Chief  Executive Officer  may  reasonably
    request  from  time  to time  for  a monthly  fee  of $16,667  and  shall be
    reimbursed for  reasonable  expenses incurred  in  the performance  of  such
    services and (ii) the Executive shall not be an employee of the Company.
 
    3.  COMPENSATION.
 
        (a)   BASE  SALARY.  During  the Employment Period,  the Executive shall
    receive an annual base salary ("Annual Base Salary") of not less than  Three
    Hundred   Thousand  Dollars  ($300,000),  payable  in  accordance  with  the
    Company's regular payroll practice for  its senior executives, as in  effect
    from  time to  time. During  the Employment  Period, the  Annual Base Salary
    shall be reviewed for possible increase  at least annually. Any increase  in
    the Annual Base Salary shall not limit or reduce any other obligation of the
    Company  under this Agreement.  The Annual Base Salary  shall not be reduced
    after any such increase, and the term "Annual Base Salary" shall  thereafter
    refer to the Annual Base Salary as so increased.
 
        (b)    INCENTIVE  COMPENSATION.    During  the  Employment  Period,  the
    Executive shall participate in such short-term incentive compensation  plans
    and  long-term incentive compensation plans as  shall be decided upon in the
    discretion of the  Compensation Committee  of the  Board (the  "Compensation
    Committee")  (the  latter  to  consist  of  plans  offering  stock  options,
    restricted stock and/or other  long-term incentive compensation),  providing
    him  with the  opportunity to earn,  on an annualized  basis, short-term and
    long-term incentive compensation  ("Incentive Compensation")  (i) which,  in
    the  aggregate, is  in the  same proportion  to the  Executive's Annual Base
    Salary as the aggregate  "Incentive Compensation" that  the Chairman has  or
    would  have an opportunity  to earn under his  Employment Agreement with the
    Company of even  date herewith  is to  the Chairman's  "Annual Base  Salary"
    under  such Employment  Agreement, and  (ii) is  payable in  accordance with
    standards   (I.E.,   performance   criteria,   performance   levels,   etc.)
    substantially  similar to those that are or would be applicable with respect
    to  the  "Incentive  Compensation"  payable  to  the  Chairman  under   such
    Employment Agreement.
 
        (c)   OTHER BENEFITS.  In  addition, and without limiting the generality
    of the  foregoing, during  the  Employment Period  and thereafter:  (A)  the
    Executive  shall  be entitled  to participate  in all  applicable incentive,
    savings and  retirement  plans,  practices, policies  and  programs  of  the
    Company  and its  affiliates to the  same extent as  other senior executives
    (or, where applicable, retired  senior executives) of  the Company, and  (B)
    the  Executive and/or the Executive's  family, as the case  may be, shall be
    eligible for immediate participation in (and without any limitation for  any
    pre-existing   condition),  and  shall  receive   all  benefits  under,  all
    applicable welfare benefit plans, practices, policies and programs  provided
    by  the Company and its  affiliates, including, without limitation, medical,
    prescription,  dental,   disability,  salary   continuance,  employee   life
    insurance,  accidental death and travel insurance plans and programs, to the
    same extent as other senior executives (or, where applicable, retired senior
    executives) of the Company; provided, however that the Executive's aggregate
    benefits as a retired senior executive  under the plans described in  clause
    (B)  above shall not be less than  the benefits provided by Interstate Power
    to its retired senior executive officers as of the date of this Agreement.
 
        (d)  PERQUISITES.  During the Employment Period, the Executive shall  be
    entitled  to receive such perquisites as the Company may establish from time
    to time which are commensurate with his position and at least comparable  to
    those received by other senior executives at the Company.
 
        (e)   EXPENSE REIMBURSEMENT.  The  Company shall reimburse the Executive
    for all reasonable and documented expenses incurred by the Executive in  the
    performance of the Executive's duties under this Agreement.
 
        (f)  SUPPLEMENTAL RETIREMENT BENEFIT.  During the Employment Period, the
    Executive  shall  participate  in  a  retirement  plan  and/or  supplemental
    retirement plan such  that the  aggregate value of  the retirement  benefits
    that  will be payable to or with respect  to the Executive at the end of the
    Employment Period under  all defined benefit  plans of the  Company and  its
    affiliates
 
                                      J-2
<PAGE>
    (whether  qualified or not) will not be less than the benefits he would have
    received (assuming his employment through the end of the Employment  Period)
    under the Interstate Power Company Retirement Income Plan and the Interstate
    Power Company Supplemental Retirement Plan, as in effect on the date of this
    Agreement.
 
    4.  TERMINATION OF EMPLOYMENT.
 
        (a)   DEATH OR  DISABILITY.  The  Executive's employment shall terminate
    automatically upon the Executive's death  during the Employment Period.  The
    Company shall be entitled to terminate the Executive's employment because of
    the  Executive's Disability during the Employment Period. "Disability" means
    that (i) the  Executive has been  unable, for  a period of  one hundred  and
    eighty  (180) consecutive business  days, to perform  the Executive's duties
    under this Agreement, as a result  of physical or mental illness or  injury,
    and (ii) a physician selected by the Company or its insurers, and acceptable
    to  the Executive  or the  Executive's legal  representative, has determined
    that the Executive's incapacity is total and permanent. A termination of the
    Executive's employment by the Company  for Disability shall be  communicated
    to  the Executive by written notice and  shall be effective on the thirtieth
    (30th) day after receipt  of such notice by  the Executive (the  "Disability
    Effective  Date"), unless the Executive  returns to full-time performance of
    the Executive's duties before the Disability Effective Date.
 
        (b)  BY THE COMPANY.
 
           (i) The Company may terminate  the Executive's employment during  the
       Employment Period for Cause or without Cause. "Cause" means:
 
               A.     the  willful  and   continued  failure  of  the  Executive
           substantially to perform the Executive's duties under this  Agreement
           (other  than as  a result of  physical or mental  illness or injury),
           after the Board of Directors of the Company (the "Board") delivers to
           the Executive  a  written  demand for  substantial  performance  that
           specifically  identifies the manner in  which the Board believes that
           the Executive has not substantially performed the Executive's duties;
           or
 
               B.   illegal conduct  or gross  misconduct by  the Executive,  in
           either  case that is willful and results in material and demonstrable
           damage to the business or reputation of the Company.
 
       No act or failure to act on the part of the Executive shall be considered
       "willful" unless it is done, or omitted  to be done, by the Executive  in
       bad  faith or  without reasonable belief  that the  Executive's action or
       omission was in the best interests of the Company. Any act or failure  to
       act  that is  based upon  authority given  pursuant to  a resolution duly
       adopted by the Board, or the advice of counsel for the Company, shall  be
       conclusively presumed to be done, or omitted to be done, by the Executive
       in good faith and in the best interests of the Company.
 
           (ii)  A termination of the Executive's  employment for Cause shall be
       effected in accordance with the  following procedures. The Company  shall
       give  the Executive written notice ("Notice of Termination for Cause") of
       its intention to terminate the Executive's employment for Cause,  setting
       forth  in reasonable detail the specific conduct of the Executive that it
       considers to  constitute  Cause and  the  specific provision(s)  of  this
       Agreement on which it relies, and stating the date, time and place of the
       Board Meeting for Cause. The "Board Meeting for Cause" means a meeting of
       the  Board  at  which  the  Executive's  termination  for  Cause  will be
       considered, that takes  place not less  than ten (10)  and not more  than
       twenty  (20) business  days after  the Executive  receives the  Notice of
       Termination for  Cause.  The Executive  shall  be given  an  opportunity,
       together  with counsel, to be  heard at the Board  Meeting for Cause. The
       Executive's termination  for  Cause shall  be  effective when  and  if  a
       resolution is duly adopted at the Board Meeting for Cause by a two-thirds
       vote of the entire
 
                                      J-3
<PAGE>
       membership  of the Board,  excluding employee directors,  stating that in
       the good  faith opinion  of the  Board, the  Executive is  guilty of  the
       conduct  described  in  the Notice  of  Termination for  Cause,  and that
       conduct constitutes Cause under this Agreement.
 
          (iii) A termination of the Executive's employment without Cause  shall
       be  effected  in accordance  with the  following procedures.  The Company
       shall give the Executive written  notice ("Notice of Termination  Without
       Cause")  of its intention to terminate the Executive's employment without
       Cause, stating the  date, time  and place  of the  Board Meeting  without
       Cause.  The "Board Meeting without Cause" means a meeting of the Board at
       which the Executive's termination without Cause will be considered,  that
       takes place not less than ten (10) and not more than twenty (20) business
       days  after  the Executive  receives  the Notice  of  Termination without
       Cause. The  Executive  shall  be  given  an  opportunity,  together  with
       counsel,  to be heard at the Board Meeting without Cause. The Executive's
       termination without Cause shall be effective when and if a resolution  is
       duly  adopted at the Board Meeting without  Cause by a two-thirds vote of
       the entire membership of the Board, excluding employee directors, stating
       that the Executive is terminated without Cause.
 
        (c)  GOOD REASON.
 
           (i) The Executive may terminate employment for Good Reason or without
       Good Reason. "Good Reason" means:
 
               A.  the assignment to the Executive of any duties inconsistent in
           any respect  with  paragraphs  (a)  and (b)  of  Section  2  of  this
           Agreement,  or  any other  action by  the Company  that results  in a
           diminution  in  the  Executive's   position,  authority,  duties   or
           responsibilities,   other   than  an   isolated,   insubstantial  and
           inadvertent action that is not taken in bad faith and is remedied  by
           the  Company  promptly  after  receipt  of  notice  thereof  from the
           Executive;
 
               B.  any failure  by the Company to  comply with any provision  of
           Section  3 of this  Agreement, other than  an isolated, insubstantial
           and inadvertent  failure  that it  not  taken  in bad  faith  and  is
           remedied by the Company promptly after receipt of notice thereof from
           the Executive;
 
               C.   any requirement by the Company that the Executive's services
           be rendered  primarily at  a location  or locations  other than  that
           provided for in paragraph (c) of Section 2 of this Agreement;
 
               D.   any purported  termination of the  Executive's employment by
           the Company for a  reason or in a  manner not expressly permitted  by
           this Agreement;
 
               E.   any failure by  the Company to comply  with paragraph (c) of
           Section 11 of this Agreement; or
 
               F.  any other substantial breach of this Agreement by the Company
           that either is  not taken in  good faith  or is not  remedied by  the
           Company promptly after receipt of notice thereof from the Executive.
 
           (ii)  A termination  of employment by  the Executive  for Good Reason
       shall be effectuated  by giving  the Company written  notice ("Notice  of
       Termination for Good Reason") of the termination within six (6) months of
       the  event constituting Good  Reason, setting forth  in reasonable detail
       the specific conduct of the Company that constitutes Good Reason and  the
       specific  provision(s) of this Agreement on which the Executive relies. A
       termination of  employment by  the  Executive for  Good Reason  shall  be
       effective  on the  fifth (5th) business  day following the  date when the
       Notice of Termination for  Good Reason is given,  unless the notice  sets
       forth  a later date (which date shall  in no event be later than (thirty)
       30 days after the notice is given).
 
                                      J-4
<PAGE>
          (iii) A termination  of the  Executive's employment  by the  Executive
       without  Good  Reason shall  be effected  by  giving the  Company written
       notice of the termination.
 
        (d)  DATE OF TERMINATION.  The  "Date of Termination" means the date  of
    the  Executive's death, the Disability Effective Date, the date on which the
    termination of  the  Executive's employment  by  the Company  for  Cause  or
    without  Cause or by the Executive for Good Reason is effective, or the date
    on which  the  Executive  gives  the Company  notice  of  a  termination  of
    employment without Good Reason, as the case may be.
 
    5.  OBLIGATIONS OF THE COMPANY UPON TERMINATION.
 
        (a)   BY THE COMPANY  OTHER THAN FOR CAUSE,  DEATH OR DISABILITY; BY THE
    EXECUTIVE FOR GOOD REASON.   If, during the  Employment Period, the  Company
    terminates  the  Executive's  employment,  other than  for  Cause,  Death or
    Disability, or  the Executive  terminates employment  for Good  Reason,  the
    Company  shall continue to  provide the Executive  with the compensation and
    benefits set forth in paragraphs (a), (b) and (c) of Section 3 as if he  had
    remained  employed by the Company pursuant to this Agreement through the end
    of the Employment Period and then retired (at which time he will be  treated
    as  eligible for all retiree welfare benefits and other benefits provided to
    retired senior executives, as set forth in Section 3(c)); PROVIDED, that the
    Incentive Compensation  for  such  period  shall be  equal  to  the  maximum
    Incentive  Compensation that the Executive would  have been eligible to earn
    for  such  period;  PROVIDED,  further,  that  in  lieu  of  stock  options,
    restricted  stock and other stock-based awards,  the Executive shall be paid
    cash equal to the fair market value (without regard to any restrictions)  of
    the  stock options, restricted stock and other stock-based awards that would
    otherwise have  been granted;  PROVIDED,  further, that  to the  extent  any
    benefits described in paragraph (c) of Section 3 cannot be provided pursuant
    to  a plan  or program  maintained by  the Company  for its  executives, the
    Company shall  provide such  benefits outside  such plan  or program  at  no
    additional cost (including without limitation tax cost) to the Executive and
    his family; and PROVIDED, finally, that during any period when the Executive
    is  eligible to  receive benefits  of the  type described  in clause  (B) of
    paragraph (c)  of  Section  3  under  another  employer-provided  plan,  the
    benefits  provided by the Company under this  paragraph (a) of Section 5 may
    be made secondary to  those provided under such  other plan. In addition  to
    the  foregoing, any restricted stock outstanding  on the Date of Termination
    shall be  fully  vested  as of  the  Date  of Termination  and  all  options
    outstanding on the Date of Termination shall be fully vested and exercisable
    and  shall  remain  in  effect  and exercisable  through  the  end  of their
    respective terms,  without  regard to  the  termination of  the  Executive's
    employment.  The payments and  benefits provided pursuant  to this paragraph
    (a) of Section 5 are intended as liquidated damages for a termination of the
    Executive's employment by the Company other than for Cause or Disability  or
    for  the actions of the Company leading  to a termination of the Executive's
    employment by  the Executive  for Good  Reason, and  shall be  the sole  and
    exclusive remedy therefor.
 
        (b)   DEATH AND DISABILITY.  If the Executive's employment is terminated
    by reason  of the  Executive's  death or  Disability during  the  Employment
    Period,  the  Company shall  pay to  the Executive  or, in  the case  of the
    Executive's death, to the Executive's designated beneficiaries (or, if there
    is no  such beneficiary,  to the  Executive's surviving  spouse, or  if  the
    Executive  is not survived by  a spouse, to the  Executive's estate or legal
    representative), in a  lump sum in  cash within thirty  (30) days after  the
    Date  of  Termination,  the  sum  of  the  following  amounts  (the "Accrued
    Obligations"): (1) any portion of the Executive's Annual Base Salary through
    the Date of Termination that has been  earned but not yet been paid; (2)  an
    amount  representing the Incentive Compensation for the period that includes
    the Date of Termination,  computed by assuming that  the amount of all  such
    Incentive  Compensation  would  be  equal  to  the  maximum  amount  of such
    Incentive Compensation that the Executive  would have been eligible to  earn
    for such period, and multiplying that amount by a fraction, the numerator of
    which  is the number of days in such period through the Date of Termination,
    and the denominator of  which is the  total number of  days in the  relevant
    period;   (3)  any   compensation  previously  deferred   by  the  Executive
 
                                      J-5
<PAGE>
    (together with any accrued  interest or earnings thereon)  that has not  yet
    been  paid;  and  (4)  any accrued  but  unpaid  Incentive  Compensation and
    vacation pay. Any deferred compensation (together with any accrued  interest
    or  earnings thereon, if any) will be  paid in accordance with the terms and
    conditions applicable to such deferred compensation.
 
        (c)  BY  THE COMPANY FOR  CAUSE; BY  THE EXECUTIVE OTHER  THAN FOR  GOOD
    REASON.   If  the Executive's  employment is  terminated by  the Company for
    Cause during the Employment Period, the Company shall pay the Executive  the
    Annual  Base Salary through  the Date of  Termination and the  amount of any
    compensation previously deferred by the Executive (together with any accrued
    interest or earnings thereon), in each case to the extent not yet paid,  and
    the  Company shall have no further  obligations under this Agreement, except
    as specified in  Section 6  below. If the  Executive voluntarily  terminates
    employment  during the  Employment Period, other  than for  Good Reason, the
    Company shall pay the Accrued Obligations to the Executive in a lump sum  in
    cash  within thirty (30)  days of the  Date of Termination,  and the Company
    shall have no further obligations under this Agreement, except as  specified
    in Section 6 below.
 
    6.   NON-EXCLUSIVITY OF RIGHTS.  Nothing  in this Agreement shall prevent or
limit the Executive's continuing or  future participation in any plan,  program,
policy  or practice provided by the Company for which the Executive may qualify,
nor shall anything in  this Agreement limit or  otherwise affect such rights  as
the  Executive may have under any contract  or agreement with the Company or any
of its  affiliates  relating to  subject  matter other  than  that  specifically
addressed  herein.  Vested  benefits and  other  amounts that  the  Executive is
otherwise entitled to  receive under  the Incentive  Compensation, the  deferred
compensation and other benefit programs listed in paragraph (c) of Section 3, or
any  other plan, policy,  practice or program  of, or any  contract or agreement
with, the Company or any of its  affiliates on or after the Date of  Termination
shall  be  payable in  accordance  with the  terms  of each  such  plan, policy,
practice, program,  contract  or  agreement,  as the  case  may  be,  except  as
explicitly modified by this Agreement.
 
    7.  FULL SETTLEMENT.  The Company's obligation to make the payments provided
for in, and otherwise to perform its obligations under, this Agreement shall not
be  affected by any  set-off, counterclaim, recoupment,  defense or other claim,
right or action that the Company may have against the Executive or others. In no
event shall the  Executive be  obligated to seek  other employment  or take  any
other  action by way of mitigation of the amounts payable to the Executive under
any of the  provisions of  this Agreement. The  amounts payable  by the  Company
under  this Agreement shall  not be offset  or reduced by  any amounts otherwise
receivable or received by the Executive from any source, except as  specifically
provided  in paragraph (a)  of Section 5  with respect to  benefits described in
clause (B) of paragraph (c) of Section 3.
 
    8.   CONFIDENTIAL INFORMATION.   The  Executive shall  hold in  a  fiduciary
capacity  for the benefit of the Company all secret or confidential information,
knowledge or data relating to the Company or any of its affiliated companies and
their respective businesses  that the Executive  obtains during the  Executive's
employment  by the Company  or any of  its affiliated companies  and that is not
public knowledge (other than  as a result of  the Executive's violation of  this
Section  8) ("Confidential  Information"). The Executive  shall not communicate,
divulge or disseminate Confidential Information at any time during or after  the
Executive's  employment with the Company, except  with the prior written consent
of the Company or  as otherwise required  by law or legal  process. In no  event
shall  any asserted violation of  the provisions of this  Section 8 constitute a
basis for  deferring  or  withholding  any  amounts  otherwise  payable  to  the
Executive under this Agreement.
 
    9.  LIMITATION ON PAYMENTS.
 
        (a)  Notwithstanding  any  other  provision of  this  Agreement,  if any
    portion of any payment  under this Agreement, or  under any other  agreement
    with  or plan  of the  Company or  its affiliates  (in the  aggregate "Total
    Payments"), would constitute an "excess  parachute payment," then the  Total
    Payments to be made to the Executive shall be reduced such that the value of
    the aggregate Total Payments that the Executive is entitled to receive shall
    be One Dollar ($1) less than the
 
                                      J-6
<PAGE>
    maximum  amount which the Executive may  receive without becoming subject to
    the tax imposed by Section 4999 (or any successor provision) of the Internal
    Revenue Code of 1986, as amended (the  "Code") or which the Company may  pay
    without  loss  of  deduction  under  Section 280G(a)  of  the  Code  (or any
    successor provision).  For purposes  of this  Agreement, the  terms  "excess
    parachute payment" and "parachute payments" shall have the meanings assigned
    to  them in Section 280G of the  Code (or any successor provision), and such
    "parachute payments" shall be valued as provided therein. Present value  for
    purposes  of this Agreement  shall be calculated  in accordance with Section
    1274(b)(2) of the  Code (or  any successor provision).  Within fifteen  (15)
    days  following the  Date of  Termination or  notice by  the Company  to the
    Executive of its belief that there is a payment or benefit due the Executive
    which will result in an excess parachute payment as defined in Section  280G
    of  the Code (or any successor provision), the Executive and the Company, at
    the  Company's  expense,  shall  obtain  the  opinion  (which  need  not  be
    unqualified)  of nationally recognized tax counsel selected by the Company's
    independent auditors and acceptable to the Executive in his sole  discretion
    (which  may be regular  outside counsel to the  Company), which opinion sets
    forth (i) the amount of the Base Period Income, (ii) the amount and  present
    value of Total Payments and (iii) the amount and present value of any excess
    parachute  payments  determined without  regard to  the limitations  of this
    paragraph (a) of Section 9. As used in this Agreement, the term "Base Period
    Income" means  an amount  equal to  the Executive's  "annualized  includible
    compensation  for the base  period" as defined in  Section 280G(d)(1) of the
    Code (or any successor provision). For  purposes of such opinion, the  value
    of  any  noncash  benefits  or  any deferred  payment  or  benefit  shall be
    determined by  the Company's  independent auditors  in accordance  with  the
    principles  of Sections  280G(d)(3) and  (4) of  the Code  (or any successor
    provisions), which determination shall be evidenced in a certificate of such
    auditors addressed to the Company and  the Executive. Such opinion shall  be
    dated  as of the  Date of Termination  and addressed to  the Company and the
    Executive and shall be binding upon  the Company and the Executive. If  such
    opinion  determines that  there would  be an  excess parachute  payment, any
    payment or benefit  determined by  such counsel  to be  includible in  Total
    Payments  shall be  reduced or eliminated  as specified by  the Executive in
    writing delivered to the Company within  thirty (30) days of his receipt  of
    such  opinion or, if the  Executive fails to so  notify the Company, then as
    the  Company  shall  reasonably  determine,  so  that  under  the  bases  of
    calculations  set forth  in such opinion  there will be  no excess parachute
    payment. If such legal  counsel so requests in  connection with the  opinion
    required  by this paragraph (a) of Section  9, the Executive and the Company
    shall obtain, at the Company's expense, and the legal counsel may rely on in
    providing the  opinion,  the  advice  of  a  firm  of  recognized  executive
    compensation   consultants  as  to   the  reasonableness  of   any  item  of
    compensation to be received by the Executive. If the provisions of  Sections
    280G and 4999 of the Code (or any successor provisions) are repealed without
    succession,  then this  paragraph (a)  of Section 9  shall be  of no further
    force or effect.
 
        (b) If, notwithstanding the provisions of paragraph (a) of Section 9, it
    is ultimately determined by a court or pursuant to a final determination  by
    the  Internal Revenue Service that any  portion of Total Payments is subject
    to the tax (the "Excise  Tax") imposed by Section 4999  of the Code (or  any
    successor  provision), the Company shall pay  to the Executive an additional
    amount (the "Gross-Up  Payment") such that  the net amount  retained by  the
    Executive  after deduction  of any  Excise Tax  and any  interest charges or
    penalties in  respect of  the imposition  of such  Excise Tax  (but not  any
    federal,  state or local income tax) on the Total Payments, and any federal,
    state and local income tax and Excise  Tax upon the payment provided for  by
    this  paragraph (b) of Section 9, shall  be equal to the Total Payments. For
    purposes of determining the  amount of the  Gross-Up Payment, the  Executive
    shall  be deemed to pay federal income taxes at the highest marginal rate of
    federal income taxation in the calendar  year in which the Gross-Up  Payment
    is to be made and state and local income taxes at the highest marginal rates
    of taxation in the state and locality of the Executive's domicile for income
    tax  purposes on the date  the Gross-Up Payment is  made, net of the maximum
    reduction in federal income taxes which could be obtained from deduction  of
    such state and local taxes.
 
                                      J-7
<PAGE>
    10.    ATTORNEYS' FEES.   The  Company agrees  to pay,  as incurred,  to the
fullest extent permitted by law, all legal fees and expenses that the  Executive
may  reasonably incur as a result of  any contest (regardless of the outcome) by
the Company, the  Executive or others  of the validity  or enforceability of  or
liability  under,  or  otherwise  involving, any  provision  of  this Agreement,
together with interest  on any delayed  payment at the  applicable federal  rate
provided for in Section 7872(f)(2)(A) of the Code.
 
    11.  SUCCESSORS.
 
        (a)  This Agreement is personal to  the Executive and, without the prior
    written consent of the  Company, shall not be  assignable by the  Executive.
    This  Agreement shall  inure to  the benefit  of and  be enforceable  by the
    Executive's legal representatives.
 
        (b) This Agreement shall inure to the benefit of and be binding upon the
    Company and its successors and assigns.
 
        (c) The Company shall require any successor (whether direct or indirect,
    by purchase, merger, consolidation or otherwise) to all or substantially all
    of the business and/or assets of  the Company expressly to assume and  agree
    to perform this Agreement in the same manner and to the same extent that the
    Company  would have been  required to perform  it if no  such succession had
    taken place.  As used  in  this Agreement,  "Company"  shall mean  both  the
    Company  as defined above and any such  successor that assumes and agrees to
    perform this Agreement, by operation of law or otherwise.
 
    12.  MISCELLANEOUS.
 
        (a) This Agreement  shall be  governed by, and  construed in  accordance
    with,  the laws  of the  State of Iowa,  without reference  to principles of
    conflict of  laws.  The captions  of  this Agreement  are  not part  of  the
    provisions  hereof and shall have no force or effect. This Agreement may not
    be amended or modified except by a written agreement executed by the parties
    hereto or their respective successors and legal representatives.
 
        (b) All notices and other  communications under this Agreement shall  be
    in  writing and  shall be given  by hand delivery  to the other  party or by
    facsimile, addressed as follows:
 
        If to the Executive:
       Mr. Wayne Stoppelmoor
       [          ]
       If to the Company:
       Interstate Energy Corporation
       222 West Washington Avenue
       P.O. Box 2568
       Madison, Wisconsin 53701-2568
       Attn: General Counsel
 
    or to such other address as either  party furnishes to the other in  writing
    in   accordance  with  this  paragraph  (b)   of  Section  12.  Notices  and
    communications shall be effective when actually received by the addressee.
 
        (c)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement  shall  not affect  the validity  or  enforceability of  any other
    provision of this  Agreement. If any  provision of this  Agreement shall  be
    held  invalid  or  unenforceable  in part,  the  remaining  portion  of such
    provision, together  with  all other  provisions  of this  Agreement,  shall
    remain  valid and enforceable and  continue in full force  and effect to the
    fullest extent consistent with law.
 
                                      J-8
<PAGE>
        (d) Notwithstanding any other provision  of this Agreement, the  Company
    may  withhold from amounts payable under  this Agreement all federal, state,
    local and foreign taxes that are required to be withheld by applicable  laws
    or regulations.
 
        (e)  The  Executive's or  the Company's  failure  to insist  upon strict
    compliance with  any provisions  of,  or to  assert  any right  under,  this
    Agreement  (including,  without limitation,  the right  of the  Executive to
    terminate employment for Good Reason pursuant to paragraph (c) of Section  4
    of  this Agreement) shall not be deemed to  be a waiver of such provision or
    right or of any other provision of or right under this Agreement.
 
        (f) The  Executive  and  the Company  acknowledge  that  this  Agreement
    supersedes  any other  agreement between  the Executive  and the  Company or
    Interstate Power concerning  the subject matter  hereof, including,  without
    limitation,   any  change  in  control  protection  agreements  between  the
    Executive and Interstate Power.
 
        (g) The rights and  benefits of the Executive  under this Agreement  may
    not  be anticipated, alienated or  subject to attachment, garnishment, levy,
    execution or other legal or equitable process except as required by law. Any
    attempt by the  Executive to anticipate,  alienate, assign, sell,  transfer,
    pledge,  encumber or charge the same shall be void. Payments hereunder shall
    not be considered  assets of  the Executive in  the event  of insolvency  or
    bankruptcy.
 
        (h)  This Agreement  may be  executed in  several counterparts,  each of
    which shall be deemed  an original, and  said counterparts shall  constitute
    but one and the same instrument.
 
    13.   EFFECTIVENESS  OF AGREEMENT.   The effectiveness of  this Agreement is
subject to  the  consummation of  the  Combination  (as defined  in  the  Merger
Agreement).  If for any reason the  Combination is not consummated in accordance
with the terms of the Merger Agreement, this Agreement shall be null and void AB
INITIO.
 
    IN WITNESS WHEREOF, the Executive has hereunto set the Executive's hand and,
pursuant to the authorization of the Board of Directors, the Company has  caused
this  Agreement to be executed in its name on  its behalf, all as of the day and
year first above written.
 
                                          INTERSTATE ENERGY CORPORATION
                                          By: ______________________________
 
                                          Name: ____________________________
 
                                          Title: ___________________________
 
                                          __________________________________
                                                  WAYNE STOPPELMOOR
 
                                      J-9
<PAGE>
                                                                         ANNEX K
 
                              EMPLOYMENT AGREEMENT
 
    THIS   AGREEMENT  by  and  between  Interstate  Power  Company,  a  Delaware
corporation (the "Company"), and  Michael Chase (the  "Executive"), dated as  of
the           day of           , 199 .
 
    WHEREAS,  the Company, WPL  Holdings, Inc. ("WPL  Holdings"), IES Industries
Inc., WPLH Acquisition Co. and Interstate Power Company, a Wisconsin corporation
(collectively, the "Merger Parties"), have entered into an Agreement and Plan of
Merger dated as of November 10, 1995, as amended (the "Merger Agreement"); and
 
    WHEREAS, the Merger Parties  wish to provide for  the orderly succession  of
management of the Company following the Effective Time (as defined in the Merger
Agreement); and
 
    WHEREAS,  the Merger Parties  further wish to provide  for the employment by
the Company of the Executive, and the Executive wishes to serve the Company,  in
the capacities and on the terms and conditions set forth in this Agreement:
 
    NOW, THEREFORE, it is hereby agreed as follows:
 
    1.   EMPLOYMENT  PERIOD.   The Company shall  employ the  Executive, and the
Executive shall serve the Company as an employee and officer of the Company,  on
the  terms and conditions set forth in this Agreement, for the period commencing
on the  Effective  Time  and ending  on  the  last day  of  the  calendar  month
immediately  following the calendar month in  which the Executive attains age 62
(the "Employment Period").  Upon the  termination of the  Employment Period  the
Executive  will have  the status  of a retired  senior executive  officer of the
Company and shall  be entitled  to all of  the rights,  privileges and  benefits
provided to such retired officers.
 
    2.  POSITION AND DUTIES.
 
        (a)   TITLE.  During the Employment Period, the Executive shall serve as
    the President of the Company.
 
        (b)  DUTIES.  During the  Employment Period, the Executive shall  report
    to the Board of Directors of the Company (the "Board") and shall perform the
    duties,   undertake   the  responsibilities   and  exercise   the  authority
    customarily performed, undertaken  and exercised  by persons  situated in  a
    similar executive capacity and shall additionally perform such duties as may
    be  reasonably assigned from time to time  by the Board, consistent with his
    status as President. During the Employment Period, and excluding any periods
    of vacation and sick leave to which the Executive is entitled, the Executive
    shall devote the  whole of  his attention  and time  during normal  business
    hours  (and  outside those  hours when  reasonably  necessary to  his duties
    hereunder) to the  business and affairs  of the Company  and, to the  extent
    necessary  to discharge the responsibilities assigned to the Executive under
    this Agreement, use  the Executive's  reasonable best efforts  to carry  out
    such responsibilities faithfully and efficiently. It shall not be considered
    a  violation  of the  foregoing  for the  Executive  to serve  on corporate,
    industry, civic  or  charitable  boards  or  committees,  so  long  as  such
    activities  do  not  significantly  interfere with  the  performance  of the
    Executive's responsibilities as  an employee  of the  Company in  accordance
    with this Agreement.
 
        (c)   OFFICE.   The  Executive's services  hereunder shall  be performed
    primarily at the executive offices of the Company located in Dubuque,  Iowa,
    subject to such business travel as shall be necessary and appropriate.
 
                                      K-1
<PAGE>
    3.  COMPENSATION.
 
        (a)   BASE SALARY.   The Executive's  compensation during the Employment
    Period shall  be determined  by the  Board upon  the recommendation  of  the
    Compensation  and Personnel Committee (or  the appropriate committee) of the
    Board, subject to the next sentence  and paragraph (b) of Section 3.  During
    the Employment Period, the Executive shall receive an annual salary ("Annual
    Base  Salary") of not  less than his  aggregate annual base  salary from the
    Company and its affiliates in effect immediately before the Effective  Time.
    The  Annual Base  Salary shall be  payable in accordance  with the Company's
    regular payroll practice for its senior  executives, as in effect from  time
    to  time.  During the  Employment Period,  the Annual  Base Salary  shall be
    reviewed for possible increase at least annually. Any increase in the Annual
    Base Salary shall not  limit or reduce any  other obligation of the  Company
    under  this Agreement. The Annual Base Salary shall not be reduced after any
    such increase, and the term "Annual  Base Salary" shall thereafter refer  to
    the Annual Base Salary as so increased.
 
        (b)    INCENTIVE  COMPENSATION.    During  the  Employment  Period,  the
    Executive shall participate in such short-term incentive compensation  plans
    and  long-term incentive compensation plans as  shall be decided upon in the
    discretion of the Compensation Committee of the Board (or other  appropriate
    committee)   (the  latter  to  consist  of  plans  offering  stock  options,
    restricted stock and/or other long-term incentive compensation), offered  by
    WPL  Holdings and its present  and future affiliates, to  the same extent as
    other senior executives of  WPL Holdings and  its primary subsidiaries  (the
    "Incentive Compensation").
 
        (c)   OTHER BENEFITS.  In  addition, and without limiting the generality
    of the  foregoing, during  the  Employment Period  and thereafter:  (A)  the
    Executive  shall  be entitled  to participate  in all  applicable incentive,
    savings and  retirement  plans,  practices, policies  and  programs  of  WPL
    Holdings  and its affiliates  to the same extent  as other senior executives
    (or, where applicable, retired  senior executives) of  the Company, and  (B)
    the  Executive and/or the Executive's  family, as the case  may be, shall be
    eligible for  immediate participation  in (and  without any  limitation  for
    pre-existing   conditions),  and  shall  receive  all  benefits  under,  all
    applicable welfare benefit plans, practices, policies and programs  provided
    by  WPL Holdings and its affiliates, including, without limitation, medical,
    prescription,  dental,   disability,  salary   continuance,  employee   life
    insurance,  accidental death and travel insurance plans and programs, to the
    same extent as other senior executives (or, where applicable, retired senior
    executives) of the Company; provided, however that the Executive's aggregate
    benefits as a  retired senior executive  under the plans  described in  this
    clause  (B) shall not be  less than the benefits  provided by the Company to
    its retired senior executive officers as of the date of this Agreement.
 
        (d)  PERQUISITES.  During the Employment Period, the Executive shall  be
    entitled to receive such perquisites as WPL Holdings may establish from time
    to  time which are commensurate with his position and at least comparable to
    those received by other senior executives at WPL Holdings.
 
        (e)  EXPENSE REIMBURSEMENT.   The Company shall reimburse the  Executive
    for  all reasonable and documented expenses incurred by the Executive in the
    performance of the Executive's duties under this Agreement.
 
        (f)  SUPPLEMENTAL RETIREMENT BENEFIT.  During the Employment Period, the
    Executive  shall  participate  in  a  retirement  plan  and/or  supplemental
    retirement  plan such  that the aggregate  value of  the retirement benefits
    that will be payable to or with respect  to the Executive at the end of  the
    Employment  Period under  all defined benefit  plans of the  Company and its
    affiliates (whether qualified or not) will not be less than the benefits  he
    would  have  received  (assuming  his  employment  through  the  end  of the
    Employment Period) under the Interstate Power Company Retirement Income Plan
    and the Interstate Power Company Supplemental Retirement Plan, as in  effect
    on the date of this Agreement.
 
                                      K-2
<PAGE>
    4.  TERMINATION OF EMPLOYMENT.
 
        (a)   DEATH OR  DISABILITY.  The  Executive's employment shall terminate
    automatically upon the Executive's death  during the Employment Period.  The
    Company shall be entitled to terminate the Executive's employment because of
    the  Executive's Disability during the Employment Period. "Disability" means
    that (i) the  Executive has been  unable, for  a period of  one hundred  and
    eighty  (180) consecutive business  days, to perform  the Executive's duties
    under this Agreement, as a result  of physical or mental illness or  injury,
    and (ii) a physician selected by the Company or its insurers, and acceptable
    to  the Executive  or the  Executive's legal  representative, has determined
    that the Executive's incapacity is total and permanent. A termination of the
    Executive's employment by the Company  for Disability shall be  communicated
    to  the Executive by written notice and  shall be effective on the thirtieth
    (30th) day after receipt  of such notice by  the Executive (the  "Disability
    Effective  Date"), unless the Executive  returns to full-time performance of
    the Executive's duties before the Disability Effective Date.
 
        (b)  BY THE COMPANY.
 
           (i) The Company may terminate  the Executive's employment during  the
       Employment Period for Cause or without Cause. "Cause" means:
 
               A.     the  willful  and   continued  failure  of  the  Executive
           substantially to perform the Executive's duties under this  Agreement
           (other  than as  a result of  physical or mental  illness or injury),
           after the Board of Directors of the Company (the "Board") delivers to
           the Executive  a  written  demand for  substantial  performance  that
           specifically  identifies the manner in  which the Board believes that
           the Executive has not substantially performed the Executive's duties;
           or
 
               B.   illegal conduct  or gross  misconduct by  the Executive,  in
           either  case that is willful and results in material and demonstrable
           damage to the business or reputation of the Company.
 
       No act or failure to act on the part of the Executive shall be considered
       "willful" unless it is done, or omitted  to be done, by the Executive  in
       bad  faith or  without reasonable belief  that the  Executive's action or
       omission was in the best interests of the Company. Any act or failure  to
       act  that is  based upon  authority given  pursuant to  a resolution duly
       adopted by the Board, or the advice of counsel for the Company, shall  be
       conclusively presumed to be done, or omitted to be done, by the Executive
       in good faith and in the best interests of the Company.
 
           (ii)  A termination of the Executive's  employment for Cause shall be
       effected in accordance with the  following procedures. The Company  shall
       give  the Executive written notice ("Notice of Termination for Cause") of
       its intention to terminate the Executive's employment for Cause,  setting
       forth  in reasonable detail the specific conduct of the Executive that it
       considers to  constitute  Cause and  the  specific provision(s)  of  this
       Agreement on which it relies, and stating the date, time and place of the
       Board Meeting for Cause. The "Board Meeting for Cause" means a meeting of
       the  Board  at  which  the  Executive's  termination  for  Cause  will be
       considered, that takes  place not less  than ten (10)  and not more  than
       twenty  (20) business  days after  the Executive  receives the  Notice of
       Termination for  Cause.  The Executive  shall  be given  an  opportunity,
       together  with counsel, to be  heard at the Board  Meeting for Cause. The
       Executive's termination  for  Cause shall  be  effective when  and  if  a
       resolution is duly adopted at the Board Meeting for Cause by a two-thirds
       vote of the entire membership of the Board, excluding employee directors,
       stating  that in the  good faith opinion  of the Board,  the Executive is
       guilty of the conduct described in  the Notice of Termination for  Cause,
       and that conduct constitutes Cause under this Agreement.
 
          (iii)  A termination of the Executive's employment without Cause shall
       be effected  in accordance  with the  following procedures.  The  Company
       shall  give the Executive written  notice ("Notice of Termination Without
       Cause")   of    its    intention    to    terminate    the    Executive's
 
                                      K-3
<PAGE>
       employment  without Cause, stating the date,  time and place of the Board
       Meeting without Cause. The "Board Meeting without Cause" means a  meeting
       of  the Board at which the  Executive's termination without Cause will be
       considered, that takes  place not less  than ten (10)  and not more  than
       twenty  (20) business  days after  the Executive  receives the  Notice of
       Termination without Cause. The Executive  shall be given an  opportunity,
       together  with counsel, to  be heard at the  Board Meeting without Cause.
       The Executive's termination without Cause shall be effective when and  if
       a  resolution is  duly adopted  at the Board  Meeting without  Cause by a
       two-thirds vote of the entire membership of the Board, excluding employee
       directors, stating that the Executive is terminated without Cause.
 
        (c)  GOOD REASON.
 
           (i) The Executive may terminate employment for Good Reason or without
       Good Reason. "Good Reason" means:
 
               A.  the assignment to the Executive of any duties inconsistent in
           any respect  with  paragraphs  (a)  and (b)  of  Section  2  of  this
           Agreement,  or  any other  action by  the Company  that results  in a
           diminution  in  the  Executive's   position,  authority,  duties   or
           responsibilities,  or a diminution  in the overall  importance of the
           Executive's role to WPL  Holdings and its  affiliates, other than  an
           isolated,  insubstantial and inadvertent action  that is not taken in
           bad faith and is  remedied by the Company  promptly after receipt  of
           notice thereof from the Executive;
 
               B.   any failure by  the Company to comply  with any provision of
           Section 3 of  this Agreement, other  than an isolated,  insubstantial
           and  inadvertent  failure  that is  not  taken  in bad  faith  and is
           remedied by the Company promptly after receipt of notice thereof from
           the Executive;
 
               C.  any requirement by the Company that the Executive's  services
           be  rendered primarily  at a  location or  locations other  than that
           provided for in paragraph (c) of Section 2 of this Agreement;
 
               D.  any  purported termination of  the Executive's employment  by
           the  Company for a reason  or in a manner  not expressly permitted by
           this Agreement;
 
               E.  any failure  by the Company to  comply with paragraph (c)  of
           Section 11 of this Agreement; or
 
               F.  any other substantial breach of this Agreement by the Company
           that  either is  not taken in  good faith  or is not  remedied by the
           Company promptly after receipt of notice thereof from the Executive.
 
           (ii) A termination  of employment  by the Executive  for Good  Reason
       shall  be effectuated  by giving the  Company written  notice ("Notice of
       Termination for Good Reason") of the termination within three (3)  months
       of the event constituting Good Reason, setting forth in reasonable detail
       the  specific conduct of the Company that constitutes Good Reason and the
       specific provision(s) of this Agreement on which the Executive relies.  A
       termination  of  employment by  the Executive  for  Good Reason  shall be
       effective on the  fifth (5th) business  day following the  date when  the
       Notice  of Termination for  Good Reason is given,  unless the notice sets
       forth a later date (which date shall  in no event be later than  (thirty)
       30 days after the notice is given).
 
          (iii)  A termination  of the  Executive's employment  by the Executive
       without Good  Reason shall  be  effected by  giving the  Company  written
       notice of the termination.
 
                                      K-4
<PAGE>
        (d)   DATE OF TERMINATION.  The  "Date of Termination" means the date of
    the Executive's death, the Disability Effective Date, the date on which  the
    termination  of  the  Executive's employment  by  the Company  for  Cause or
    without Cause or by the Executive for Good Reason is effective, or the  date
    on  which  the  Executive  gives  the Company  notice  of  a  termination of
    employment without Good Reason, as the case may be.
 
    5.  OBLIGATIONS OF THE COMPANY UPON TERMINATION.
 
        (a)  BY THE COMPANY  OTHER THAN FOR CAUSE,  DEATH OR DISABILITY; BY  THE
    EXECUTIVE  FOR GOOD REASON.   If, during the  Employment Period, the Company
    terminates the  Executive's  employment,  other than  for  Cause,  Death  or
    Disability,  or  the Executive  terminates employment  for Good  Reason, the
    Company shall continue to  provide the Executive  with the compensation  and
    benefits  set forth in paragraphs (a), (b) and (c) of Section 3 as if he had
    remained employed by the Company pursuant to this Agreement until the end of
    the Employment Period; PROVIDED, that the annualized Incentive  Compensation
    for  such period shall be  equal to the average  of the annualized Incentive
    Compensation payable  to the  Executive  in respect  of  each of  the  three
    successive   calendar  years  ended   immediately  prior  to   the  Date  of
    Termination; PROVIDED, further  that in  lieu of  stock options,  restricted
    stock  and other stock-based awards, the  Executive shall be paid cash equal
    to the fair market value (without  regard to any restrictions) of the  stock
    options,  restricted stock and other stock-based awards that would otherwise
    have been  granted;  PROVIDED, further,  that  to the  extent  any  benefits
    described  in paragraph (c)  of Section 3  cannot be provided  pursuant to a
    plan or program maintained  by the Company for  its executives, the  Company
    shall  provide such benefits  outside such plan or  program at no additional
    cost (including  without  limitation tax  cost)  to the  Executive  and  his
    family;  and PROVIDED, finally, that during any period when the Executive is
    eligible to  receive  benefits  of  the type  described  in  clause  (B)  of
    paragraph  (c)  of  Section  3  under  another  employer-provided  plan, the
    benefits provided by the Company under  this paragraph (a) of Section 5  may
    be  made secondary to those  provided under such other  plan. In addition to
    the foregoing, any restricted stock  outstanding on the Date of  Termination
    shall  be  fully  vested as  of  the  Date of  Termination  and  all options
    outstanding on the Date of Termination shall be fully vested and exercisable
    and shall  remain  in  effect  and exercisable  through  the  end  of  their
    respective  terms,  without regard  to  the termination  of  the Executive's
    employment. The payments  and benefits provided  pursuant to this  paragraph
    (a) of Section 5 are intended as liquidated damages for a termination of the
    Executive's  employment by the Company other than for Cause or Disability or
    for the actions of the Company  leading to a termination of the  Executive's
    employment  by the  Executive for  Good Reason,  and shall  be the  sole and
    exclusive remedy therefor.
 
        (b)  DEATH AND DISABILITY.  If the Executive's employment is  terminated
    by  reason  of the  Executive's death  or  Disability during  the Employment
    Period, the  Company shall  pay to  the Executive  or, in  the case  of  the
    Executive's death, to the Executive's designated beneficiaries (or, if there
    is  no  such beneficiary,  to the  Executive's surviving  spouse, or  if the
    Executive is not survived  by a spouse, to  the Executive's estate or  legal
    representative),  in a lump  sum in cash  within thirty (30)  days after the
    Date of  Termination,  the  sum  of  the  following  amounts  (the  "Accrued
    Obligations"): (1) any portion of the Executive's Annual Base Salary through
    the  Date of Termination that has been earned  but not yet been paid; (2) an
    amount representing the Incentive Compensation for the period that  includes
    the  Date of Termination, computed  by assuming that the  amount of all such
    Incentive Compensation  would  be  equal  to  the  maximum  amount  of  such
    Incentive  Compensation that the Executive would  have been eligible to earn
    for such period, and multiplying that amount by a fraction, the numerator of
    which is the number of days in such period through the Date of  Termination,
    and  the denominator of  which is the  total number of  days in the relevant
    period; (3) any compensation previously deferred by the Executive  (together
    with  any accrued interest or earnings thereon)  that has not yet been paid;
    and (4) any
 
                                      K-5
<PAGE>
    accrued but unpaid  Incentive Compensation  and vacation  pay. Any  deferred
    compensation  (together with  any accrued  interest or  earnings thereon, if
    any) that has not yet been paid,  will be paid in accordance with the  terms
    and conditions applicable to such deferred compensation.
 
        (c)   BY  THE COMPANY FOR  CAUSE; BY  THE EXECUTIVE OTHER  THAN FOR GOOD
    REASON.  If  the Executive's  employment is  terminated by  the Company  for
    Cause  during the Employment Period, the Company shall pay the Executive the
    Annual Base Salary  through the Date  of Termination and  the amount of  any
    compensation previously deferred by the Executive (together with any accrued
    interest  or earnings thereon), in each case to the extent not yet paid, and
    the Company shall have no  further obligations under this Agreement,  except
    as  specified in  Section 6 below.  If the  Executive voluntarily terminates
    employment during the  Employment Period,  other than for  Good Reason,  the
    Company  shall pay the Accrued Obligations to the Executive in a lump sum in
    cash within thirty  (30) days of  the Date of  Termination, and the  Company
    shall  have no further obligations under this Agreement, except as specified
    in Section 6 below.
 
    6.  NON-EXCLUSIVITY OF  RIGHTS.  Subject to  Section 12(f), nothing in  this
Agreement   shall  prevent  or  limit   the  Executive's  continuing  or  future
participation in any plan, program, policy  or practice provided by the  Company
for  which the Executive may qualify, nor shall anything in this Agreement limit
or otherwise affect such rights as the Executive may have under any contract  or
agreement  with the Company or any of  its affiliates relating to subject matter
other than that specifically addressed herein. Vested benefits and other amounts
that the  Executive  is  otherwise  entitled  to  receive  under  the  Incentive
Compensation,  the deferred  compensation and  other benefit  programs listed in
paragraph (c) of Section 3, or any  other plan, policy, practice or program  of,
or  any contract or agreement  with, the Company or any  of its affiliates on or
after the Date of Termination shall be  payable in accordance with the terms  of
each  such plan, policy,  practice, program, contract or  agreement, as the case
may be, except as explicitly modified by this Agreement.
 
    7.  FULL SETTLEMENT.  The Company's obligation to make the payments provided
for in, and otherwise to perform its obligations under, this Agreement shall not
be affected by any  set-off, counterclaim, recoupment,  defense or other  claim,
right or action that the Company may have against the Executive or others. In no
event  shall the  Executive be  obligated to seek  other employment  or take any
other action by way of mitigation of the amounts payable to the Executive  under
any  of the  provisions of  this Agreement. The  amounts payable  by the Company
under this Agreement  shall not be  offset or reduced  by any amounts  otherwise
receivable  or received by the Executive from any source, except as specifically
provided in paragraph  (a) of Section  5 with respect  to benefits described  in
clause (B) of paragraph (c) of Section 3.
 
    8.    CONFIDENTIAL INFORMATION.   The  Executive shall  hold in  a fiduciary
capacity for the benefit of the Company all secret or confidential  information,
knowledge or data relating to the Company or any of its affiliated companies and
their  respective businesses that  the Executive obtains  during the Executive's
employment by the Company  or any of  its affiliated companies  and that is  not
public  knowledge (other than as  a result of the  Executive's violation of this
Section 8) ("Confidential  Information"). The Executive  shall not  communicate,
divulge  or disseminate Confidential Information at any time during or after the
Executive's employment with the Company,  except with the prior written  consent
of  the Company or  as otherwise required by  law or legal  process. In no event
shall any asserted violation  of the provisions of  this Section 8 constitute  a
basis  for  deferring  or  withholding  any  amounts  otherwise  payable  to the
Executive under this Agreement.
 
    9.  LIMITATION ON PAYMENTS.
 
        (a) Notwithstanding  any  other  provision of  this  Agreement,  if  any
    portion  of any payment  under this Agreement, or  under any other agreement
    with or  plan of  the Company  or its  affiliates (in  the aggregate  "Total
    Payments"),  would constitute an "excess  parachute payment," then the Total
    Payments to be made to the Executive shall be reduced such that the value of
    the aggregate Total Payments that the Executive is entitled to receive shall
    be One Dollar  ($1) less  than the maximum  amount which  the Executive  may
    receive without becoming subject to the tax imposed
 
                                      K-6
<PAGE>
    by Section 4999 (or any successor provision) of the Internal Revenue Code of
    1986,  as amended (the "Code") or which  the Company may pay without loss of
    deduction under Section 280G(a)  of the Code  (or any successor  provision).
    For  purposes of  this Agreement, the  terms "excess  parachute payment" and
    "parachute payments" shall  have the  meanings assigned to  them in  Section
    280G of the Code (or any successor provision), and such "parachute payments"
    shall  be valued  as provided  therein. Present  value for  purposes of this
    Agreement shall be calculated in  accordance with Section 1274(b)(2) of  the
    Code  (or any successor  provision). Within fifteen  (15) days following the
    Date of Termination or notice by the Company to the Executive of its  belief
    that there is a payment or benefit due the Executive which will result in an
    excess  parachute payment  as defined  in Section 280G  of the  Code (or any
    successor provision),  the  Executive  and the  Company,  at  the  Company's
    expense,  shall  obtain  the  opinion (which  need  not  be  unqualified) of
    nationally recognized  tax counsel  selected  by the  Company's  independent
    auditors  and acceptable to the Executive  in his sole discretion (which may
    be regular outside counsel to the Company), which opinion sets forth (i) the
    amount of the Base Period Income, (ii) the amount and present value of Total
    Payments and (iii)  the amount  and present  value of  any excess  parachute
    payments  determined without regard to the limitations of this paragraph (a)
    of Section 9. As used in this Agreement, the term "Base Period Income" means
    an amount equal to the  Executive's "annualized includible compensation  for
    the  base  period" as  defined in  Section  280G(d)(1) of  the Code  (or any
    successor provision). For purposes of such opinion, the value of any noncash
    benefits or  any deferred  payment or  benefit shall  be determined  by  the
    Company's independent auditors in accordance with the principles of Sections
    280G(d)(3)  and  (4)  of  the  Code  (or  any  successor  provisions), which
    determination shall be evidenced in a certificate of such auditors addressed
    to the Company and the Executive. Such opinion shall be dated as of the Date
    of Termination and addressed to the  Company and the Executive and shall  be
    binding  upon the Company and the Executive. If such opinion determines that
    there  would  be  an  excess  parachute  payment,  any  payment  or  benefit
    determined  by  such counsel  to be  includible in  Total Payments  shall be
    reduced or eliminated as specified by the Executive in writing delivered  to
    the  Company within thirty (30)  days of his receipt  of such opinion or, if
    the Executive fails  to so  notify the Company,  then as  the Company  shall
    reasonably  determine, so that under the  bases of calculations set forth in
    such opinion  there will  be  no excess  parachute  payment. If  such  legal
    counsel  so  requests  in  connection  with  the  opinion  required  by this
    paragraph (a) of Section 9, the  Executive and the Company shall obtain,  at
    the  Company's expense, and the  legal counsel may rely  on in providing the
    opinion,  the  advice  of  a  firm  of  recognized  executive   compensation
    consultants  as  to the  reasonableness of  any item  of compensation  to be
    received by the Executive.  If the provisions of  Sections 280G and 4999  of
    the Code (or any successor provisions) are repealed without succession, then
    this paragraph (a) of Section 9 shall be of no further force or effect.
 
        (b) If, notwithstanding the provisions of paragraph (a) of Section 9, it
    is  ultimately determined by a court or pursuant to a final determination by
    the Internal Revenue Service that any  portion of Total Payments is  subject
    to  the tax (the "Excise  Tax") imposed by Section 4999  of the Code (or any
    successor provision), the Company shall  pay to the Executive an  additional
    amount  (the "Gross-Up  Payment") such that  the net amount  retained by the
    Executive after deduction  of any  Excise Tax  and any  interest charges  or
    penalties  in respect  of the  imposition of  such Excise  Tax (but  not any
    federal, state or local income tax) on the Total Payments, and any  federal,
    state  and local income tax and Excise  Tax upon the payment provided for by
    this paragraph (b) of section 9, shall  be equal to the Total Payments.  For
    purposes  of determining the  amount of the  Gross-Up Payment, the Executive
    shall be deemed to pay federal income taxes at the highest marginal rate  of
    federal  income taxation in the calendar  year in which the Gross-Up Payment
    is to be made and state and local income taxes at the highest marginal rates
    of taxation in the state and locality of the Executive's domicile for income
    tax purposes on the date  the Gross-Up Payment is  made, net of the  maximum
    reduction  in federal income taxes which could be obtained from deduction of
    such state and local taxes.
 
                                      K-7
<PAGE>
    10.   ATTORNEYS' FEES.   The  Company agrees  to pay,  as incurred,  to  the
fullest  extent permitted by law, all legal fees and expenses that the Executive
may reasonably incur as a result of  any contest (regardless of the outcome)  by
the  Company, the Executive  or others of  the validity or  enforceability of or
liability under,  or  otherwise  involving, any  provision  of  this  Agreement,
together  with interest  on any delayed  payment at the  applicable federal rate
provided for in Section 7872(f)(2)(A) of the Code.
 
    11.  SUCCESSORS.
 
        (a) This Agreement is personal to  the Executive and, without the  prior
    written  consent of the  Company, shall not be  assignable by the Executive.
    This Agreement  shall inure  to the  benefit of  and be  enforceable by  the
    Executive's legal representatives.
 
        (b) This Agreement shall inure to the benefit of and be binding upon the
    Company and its successors and assigns.
 
        (c) The Company shall require any successor (whether direct or indirect,
    by purchase, merger, consolidation or otherwise) to all or substantially all
    of  the business and/or assets of the  Company expressly to assume and agree
    to perform this Agreement in the same manner and to the same extent that the
    Company would have  been required to  perform it if  no such succession  had
    taken  place.  As used  in  this Agreement,  "Company"  shall mean  both the
    Company as defined above and any  such successor that assumes and agrees  to
    perform this Agreement, by operation of law or otherwise.
 
    12.  MISCELLANEOUS.
 
        (a)  This Agreement  shall be governed  by, and  construed in accordance
    with, the laws  of the  State of Iowa,  without reference  to principles  of
    conflict  of  laws. The  captions  of this  Agreement  are not  part  of the
    provisions hereof and shall have no force or effect. This Agreement may  not
    be amended or modified except by a written agreement executed by the parties
    hereto or their respective successors and legal representatives.
 
        (b)  All notices and other communications  under this Agreement shall be
    in writing and  shall be given  by hand delivery  to the other  party or  by
    facsimile, addressed as follows:
 
           IF TO THE EXECUTIVE:
           Mr. Michael Chase
           [          ]
           IF TO THE COMPANY:
           Interstate Power Company
           1000 Main Street
           P.O. Box 769
           Dubuque, Iowa 52004-0769
           Attn: General Counsel
           with a copy to:
           Interstate Energy Corporation
           222 West Washington Avenue
           P.O. Box 2568
           Madison, Wisconsin 53701-2568
           Attn: General Counsel
 
    or  to such other address as either  party furnishes to the other in writing
    in  accordance  with  this  paragraph   (b)  of  Section  12.  Notices   and
    communications shall be effective when actually received by the addressee.
 
                                      K-8
<PAGE>
        (c)  The  invalidity  or  unenforceability  of  any  provision  of  this
    Agreement shall  not affect  the  validity or  enforceability of  any  other
    provision  of this  Agreement. If any  provision of this  Agreement shall be
    held invalid  or  unenforceable  in  part, the  remaining  portion  of  such
    provision,  together  with all  other  provisions of  this  Agreement, shall
    remain valid and enforceable  and continue in full  force and effect to  the
    fullest extent consistent with law.
 
        (d)  Notwithstanding any other provision  of this Agreement, the Company
    may withhold from amounts payable  under this Agreement all federal,  state,
    local  and foreign taxes that are required to be withheld by applicable laws
    or regulations.
 
        (e) The  Executive's or  the  Company's failure  to insist  upon  strict
    compliance  with  any provisions  of,  or to  assert  any right  under, this
    Agreement (including,  without limitation,  the right  of the  Executive  to
    terminate  employment for Good Reason pursuant to paragraph (c) of Section 4
    of this Agreement) shall not be deemed  to be a waiver of such provision  or
    right or of any other provision of or right under this Agreement.
 
        (f)  The  Executive  and  the Company  acknowledge  that  this Agreement
    supersedes any other agreement between the Executive and Company  concerning
    the subject matter hereof, excluding the Agreement between the Executive and
    the Company dated as of November 8, 1995, as in effect on the date hereof or
    as  hereafter  amended  from  time  to  time  (the  "Severance  Agreement");
    PROVIDED, HOWEVER,  that to  the extent  that  a payment  or benefit  to  be
    provided,  or limitation or restriction to  be imposed, under this Agreement
    is similarly to be  provided or imposed under  the Severance Agreement,  the
    Company  agrees to pay, provide or  impose that payment, benefit, limitation
    or restriction  which, in  each  case, provides  the  highest value  to  the
    Executive,  and  the  Executive agrees,  in  order to  avoid  duplication of
    payments or  benefits, that  upon  the receipt  of  any such  highest  value
    payment  or benefit under either this  Agreement or the Severance Agreement,
    as the case may be, he shall have no right to any similar payment or benefit
    of lesser value under the other agreement.
 
        (g) The rights and  benefits of the Executive  under this Agreement  may
    not  be anticipated, alienated or  subject to attachment, garnishment, levy,
    execution or other legal or equitable process except as required by law. Any
    attempt by the  Executive to anticipate,  alienate, assign, sell,  transfer,
    pledge,  encumber or charge the same shall be void. Payments hereunder shall
    not be considered  assets of  the Executive in  the event  of insolvency  or
    bankruptcy.
 
        (h)  This Agreement  may be  executed in  several counterparts,  each of
    which shall be deemed  an original, and  said counterparts shall  constitute
    but one and the same instrument.
 
    13.   EFFECTIVENESS  OF AGREEMENT.   The effectiveness of  this Agreement is
subject to  the  consummation of  the  Combination  (as defined  in  the  Merger
Agreement).  If for any reason the  Combination is not consummated in accordance
with the terms of the Merger Agreement, this Agreement shall be null and void AB
INITIO.
 
                                      K-9
<PAGE>
    IN WITNESS WHEREOF, the Executive has hereunto set the Executive's hand and,
pursuant to the authorization of the Board of Directors, the Company has  caused
this  Agreement to be executed in its name on  its behalf, all as of the day and
year first above written.
 
                                          INTERSTATE POWER COMPANY
                                          By:
 
                                          --------------------------------------
                                              Name:
                                              Title:
 
                                          --------------------------------------
                                          MICHAEL CHASE
 
                                      K-10
<PAGE>
                                                                         ANNEX L
 
Merrill Lynch
 
                                 July 11, 1996
 
Board of Directors
WPL Holdings, Inc.
P.O. Box 2568
Madison, Wisconsin 53701-2568
 
Directors:
 
    WPL Holdings, Inc. ("WPL"), IES Industries Inc. ("IES"), Interstate Power
Company ("Interstate"), WPLH Acquisition Co., a wholly-owned subsidiary of WPL
("Acquisition"), and Interstate Power Company, a wholly-owned subsidiary of
Interstate, have entered into an agreement and plan of merger dated as of
November 10, 1995, as amended as of May 22, 1996 (the "Agreement") pursuant to
which IES will be merged with and into WPL (the "IES Merger"), and Acquisition
will be merged with and into Interstate (the "Interstate Merger" and together
with the IES Merger, the "Merger"). In the IES Merger, each issued and
outstanding share of IES's common stock, no par value (the "IES Shares"), shall
be converted into the right to receive 1.01 shares of the common stock, par
value $.01 per share of WPL (the "WPL Shares"), and in the Interstate Merger,
each issued and outstanding share of Interstate's common stock, par value $3.50
per share (the "Interstate Shares"), shall be converted into the right to
receive 1.11 WPL Shares. The ratio at which IES Shares are converted into WPL
Shares, in accordance with the Agreement, is referred to herein as the "IES
Ratio", and the ratio at which Interstate Shares are converted into WPL Shares,
in accordance with the Agreement, is referred to herein as the "Interstate
Ratio." The IES Ratio and Interstate Ratio together are referred to herein as
the "Conversion Ratios." Consummation of the Merger is subject to the terms and
conditions set forth in the Agreement. The Agreement also provides for an
alternative transaction structure, to satisfy certain regulatory requirements,
in the event the structure described above does not comply with such regulatory
requirements. In connection with the Merger, WPL, IES and Interstate also have
entered into six agreements dated as of November 10, 1995, as amended as of May
22, 1996 (the "Stock Option Agreements") pursuant to which each of WPL, IES, and
Interstate, respectively, has granted to the others an option to purchase shares
of its common stock on the terms and conditions provided in such agreements,
representing in the aggregate 19.9% of the total issued and outstanding shares
of each company as of November 10, 1995.
 
    You have asked us whether, in our opinion, the Conversion Ratios
contemplated by the Agreement are fair to WPL from a financial point of view.
 
    In arriving at the opinion set forth below, we have, among other things:
 
    (1) Reviewed WPL's Annual Reports, Forms 10-K and related financial
        information for the three fiscal years ended December 31, 1995 and WPL's
        Form 10-Q and the related unaudited financial information for the
        quarterly period ending March 31, 1996;
 
                                      L-1
<PAGE>
    (2) Reviewed IES's Annual Reports, Forms 10-K and related financial
        information for the three fiscal years ended December 31, 1995 and IES's
        Form 10-Q and the related unaudited financial information for the
        quarterly period ending March 31, 1996;
 
    (3) Reviewed Interstate's Annual Reports, Forms 10-K and related financial
        information for the three fiscal years ended December 31, 1995 and
        Interstate's Form 10-Q and the related unaudited financial information
        for the quarterly period ending March 31, 1996;
 
    (4) Reviewed certain other filings with the Securities and Exchange
        Commission made by WPL, IES and Interstate, including proxy statements,
        Forms 8-K and registration statements, during the last three years;
 
    (5) Reviewed certain information, including financial forecasts, relating to
        the business, earnings, dividends, cash flow, assets and prospects of
        WPL, IES, and Interstate, furnished to us by WPL, IES, and Interstate,
        respectively;
 
    (6) Conducted discussions with members of senior management of WPL, IES and
        Interstate concerning their respective businesses, regulatory
        environments, prospects and strategic objectives and possible operating,
        administrative and capital synergies which might be realized for the
        combined companies following the Merger;
 
    (7) Reviewed the historical market prices and trading activity for WPL
        Shares, IES Shares and Interstate Shares;
 
    (8) Compared the results of operations of WPL, IES and Interstate with that
        of certain companies which we deemed to be reasonably similar to WPL,
        IES and Interstate, respectively;
 
    (9) Compared the proposed financial terms of the Merger with the financial
        terms of certain other mergers and acquisitions which we deemed to be
        relevant;
 
   (10) Analyzed the relative valuation of WPL Shares, IES Shares and Interstate
        Shares using various valuation methodologies which we deemed
        appropriate;
 
   (11) Considered the pro forma effect of the Merger, in terms of net income
        available to common stockholders, dividends per common share, book value
        per share and capitalization, on WPL Shares;
 
   (12) Reviewed the Agreement;
 
   (13) Reviewed the Stock Option Agreements; and
 
   (14) Reviewed such other financial studies and analyses and made such other
        inquiry and took into account such other matters as we deemed necessary
        or appropriate.
 
    In preparing our opinion, we have relied on the accuracy and completeness of
all information supplied or otherwise made available to us by WPL, IES and
Interstate, and we have not independently verified such information or any
underlying assumptions, conducted a physical inspection of the properties or
facilities of WPL, IES or Interstate, or undertaken or obtained any evaluation
or independent appraisal of the assets or liabilities (contingent or otherwise)
of WPL, IES or Interstate. We have assumed that the financial forecasts and
projected synergies furnished by WPL, IES and Interstate have been reasonably
prepared in accordance with accepted industry practices and reflect the best
currently available estimates and judgment of WPL's, IES's and Interstate's
management as to the expected future financial performance of WPL, IES and
Interstate, respectively, and as to the expected future projected outcomes of
various legal, regulatory and other contingencies. We have also assumed that the
Merger will be free of Federal tax to WPL, Acquisition, IES, Interstate and the
respective holders of WPL Shares, IES Shares and Interstate Shares, and we
further assume that the Merger will be accounted for as a pooling
 
                                      L-2
<PAGE>
of interests. Our opinion is based upon general economic, market, monetary and
other conditions as they exist and can be evaluated, and the information made
available to us, as of the date hereof.
 
    We have, in the past, provided financial advisory and financing services to
WPL, its subsidiary Wisconsin Power and Light Company, IES, its subsidiary IES
Utilities Inc., and Interstate and have received fees for the rendering of such
services. In addition, in the ordinary course of our securities business, we may
actively trade debt and equity securities of WPL, its subsidiary Wisconsin Power
and Light Company, IES, its subsidiary IES Utilities Inc., and Interstate for
our own account and the accounts of our customers, and we therefore may from
time to time hold a long or short position in such securities.
 
    This opinion has been prepared for the confidential use of WPL's Board of
Directors and may not be reproduced, summarized, described or referred to
without Merrill Lynch's prior written consent.
 
    On the basis of, and subject to the foregoing, we are of the opinion that
the Conversion Ratios contemplated by the Agreement are fair to WPL from a
financial point of view.
 
                                       Very truly yours,
                                       MERRILL LYNCH, PIERCE, FENNER & SMITH
                                                    INCORPORATED
 
                                      L-3
<PAGE>
                                                                         ANNEX M
 
                       MORGAN STANLEY & CO. INCORPORATED
 
                                                                   July 11, 1996
 
Board of Directors
IES Industries Inc.
IES Tower
200 First Street, S.E.
Cedar Rapids, IA 52401
 
Members of the Board of Directors:
 
    We  understand  that  IES  Industries Inc.  ("IES"  or  the  "Company"), WPL
Holdings, Inc., which upon  or immediately prior to  consummation of the  Merger
(as hereinafter defined) is proposed to be renamed Interstate Energy Corporation
("WPL"),  Interstate Power  Company ("IPC") and  WPLH Acquisition  Co., a wholly
owned subsidiary of WPL ("Merger Sub"), have entered into an Agreement and  Plan
of  Merger, dated as of November 10, 1995, and subsequently have entered into an
amendment  thereto,  dated  as  of  May  22,  1996,  (as  amended,  the  "Merger
Agreement"),  which  provides, among  other things,  for (i)  the merger  of the
Company with and into WPL (the "IES  Merger") and (ii) the merger of Merger  Sub
with and into IPC ("IPC Merger" and together with the IES Merger, the "Merger").
Pursuant  to the Merger,  (i) WPL will  be the surviving  corporation of the IES
Merger and each issued and outstanding share  of common stock, no par value,  of
the  Company (the "Company Common Stock"), other than shares held in treasury or
held by WPL  or IPC  or any  of their subsidiaries  or as  to which  dissenters'
rights  have been perfected, will be converted into the right to receive 0.98 of
a share,  or upon  satisfaction of  the McLeod  Contingency (as  defined in  the
Merger  Agreement) each share of Company Common Stock will be converted into the
right to receive 1.01 shares of common  stock, par value $.01 per share, of  WPL
(the  "WPL Common Stock"); and (ii) IPC will become a wholly owned subsidiary of
WPL and each issued and outstanding share  of common stock, par value $3.50  per
share,  of IPC (the "IPC  Common Stock"), other than  shares held in treasury or
held by  WPL  or the  Company  or  any of  their  subsidiaries or  as  to  which
dissenters'  rights have  been perfected,  will be  converted into  the right to
receive 1.11 shares (the  "IPC Ratio") of WPL  Common Stock. We also  understand
that  the  McLeod  Contingency  has been  satisfied,  and  therefore  the Merger
Agreement provides that  each share of  Company Common Stock  will be  converted
into  the right to receive 1.01 shares (the "IES Ratio") of WPL Common Stock. It
is also our understanding that the Company, WPL and IPC have entered into  Stock
Option  Agreements, each dated as of November  10, 1995, as amended (the "Option
Agreements"), which provide, among other things, for the grant by the Company to
each of WPL and to IPC of an option to acquire certain shares of Company  Common
Stock, the grant by WPL to each of the Company and IPC to acquire certain shares
of  WPL Common Stock, and the grant by IPC  to each of the Company and WPL of an
option to acquire certain  shares of IPC  Common Stock, in  each case, upon  the
terms  and conditions provided in such agreements (collectively, the "Options").
We further  understand that  the Merger  Agreement provides  for an  alternative
transaction  structure, to satisfy certain regulatory requirements, in the event
the structure outlined above does not comply with such regulatory  requirements.
The  terms and conditions of the Merger and the Options are more fully set forth
in the Merger Agreement and Option Agreements, respectively.
 
    You have asked  for our opinion  as to  whether the IES  Ratio, taking  into
account  the IPC Ratio, is fair from a financial point of view to the holders of
shares of the Company Common Stock.
 
    For purposes of the opinion set forth herein, we have:
 
    (i) analyzed certain  publicly  available  financial  statements  and  other
        information of the Company, WPL and IPC, respectively;
 
                                      M-1
<PAGE>
    (ii) analyzed  certain internal financial statements and other financial and
         operating data concerning the  Company, WPL and  IPC prepared by  their
         respective managements;
 
   (iii) analyzed  certain  financial projections  of the  Company, WPL  and IPC
         prepared by their respective managements;
 
   (iv) reviewed certain public  research reports  concerning IES,  WPL and  IPC
        prepared  by  certain  equity  research  analysts  and  discussed  these
        research reports including financial projections contained therein  with
        the managements of IES, WPL and IPC, respectively;
 
    (v) discussed  the past and  current operations and  financial condition and
        the prospects of the Company, WPL and IPC with senior executives of  the
        Company, WPL and IPC, respectively;
 
   (vi) reviewed the reported prices and trading activity of each of the Company
        Common  Stock, WPL  Common Stock,  IPC Common  Stock and  Class A common
        stock of McLeod Inc. ("McLeod");
 
   (vii) compared the financial performance of the Company, WPL and IPC and  the
         prices  and trading  activity of the  Company Common  Stock, WPL Common
         Stock and  IPC  Common Stock  with  that of  certain  other  comparable
         publicly traded companies and their securities;
 
  (viii) reviewed  the  financial terms,  to the  extent publicly  available, of
         certain comparable merger or acquisition transactions;
 
   (ix) analyzed the pro forma financial impact of the Merger on the Company;
 
    (x) participated in discussions  and negotiations  among representatives  of
        the  Company,  WPL  and IPC  and  their respective  financial  and legal
        advisors;
 
   (xi) reviewed the Merger Agreement, the Option Agreements and certain related
        documents;
 
   (xii) reviewed and  discussed  with the  Company,  WPL and  IPC  an  analysis
         prepared  by the Company,  WPL and IPC  with the assistance  of a third
         party consultant to the Company, WPL and IPC regarding estimates of the
         amount and timing of the potential cost savings to be derived from  the
         Merger;
 
  (xiii) reviewed  the registration statements filed on  Form S-1, dated May 15,
         1996 and on June 10,  1996, respectively, regarding the initial  public
         offering  of Class A common stock of McLeod (the "McLeod IPO"), as well
         as the Investor Agreement among various parties, including McLeod,  IES
         Investments Inc., Midwest Capital Group Inc., MWR Investments, Inc. and
         Clark  and Mary McLeod, entered  into as of April  1, 1996 which, among
         other things, sets forth certain restrictions on the transfer of McLeod
         common stock owned by the Company;
 
  (xiv) reviewed certain information  pertaining to  McLeod and  the McLeod  IPO
        provided  by IES and discussed certain  aspects of such information with
        the management of IES; and
 
   (xv) performed such other analyses and examinations and considered such other
        factors as we have deemed appropriate.
 
    We have  assumed  and  relied  upon  without  independent  verification  the
accuracy  and completeness of the information reviewed by us for the purposes of
this opinion. With respect to the financial projections and the estimates of the
potential cost savings to be derived from the Merger, we have assumed that  such
projections  and estimates have been reasonably prepared on bases reflecting the
best currently  available  estimates  and  judgments  of  the  future  financial
performance  of the Company,  WPL and IPC,  respectively, and of  the amount and
timing of  such cost  savings. We  have not  made any  independent valuation  or
appraisal of the assets or liabilities of the Company, WPL and IPC. In addition,
we have assumed that the Merger will be consummated in accordance with the terms
set  forth  in the  Merger Agreement,  including, among  other things,  that the
Merger will be accounted for
 
                                      M-2
<PAGE>
as  a  "pooling-of-interests"  business  combination  in  accordance  with  U.S.
generally  accepted accounting principles and that the Merger will be treated as
a tax-free reorganization and/or exchange, each pursuant to the Internal Revenue
Code of 1986.  Our opinion is  necessarily based on  economic, market and  other
conditions  as in effect on, and the information made available to us as of, the
date hereof.
 
    In arriving at  our opinion,  we have assumed  that in  connection with  the
receipt  of  all the  necessary regulatory  and  governmental approvals  for the
proposed Merger,  no restriction  will be  imposed that  would have  a  material
adverse  effect  on the  contemplated  benefits expected  to  be derived  in the
proposed Merger. In  addition, we were  not authorized to  solicit, and did  not
solicit, interest from any party with respect to a merger with or other business
combination  transaction involving the Company or any  of its assets, nor did we
have any discussions or negotiations with  any parties, other than WPL and  IPC,
in connection with the Merger.
 
    We  have acted as financial advisor to the Board of Directors of the Company
in connection with this transaction and will receive a fee for our services.  In
the  past,  Morgan  Stanley  &  Co.  Incorporated  and  its  affiliates ("Morgan
Stanley") have  provided  financial  advisory and  financing  services  for  the
Company  and WPL  and have  received fees for  the rendering  of these services.
Morgan Stanley acted as co-lead manager of the McLeod IPO.
 
    It is understood that  this letter is  for the information  of the Board  of
Directors  of the Company and may not be  used for any other purpose without our
prior written consent, except that this opinion may be included in its  entirety
in  any filing made by  the Company with the  Securities and Exchange Commission
with respect to the Merger and the transactions related thereto. In addition, we
express no recommendation as to how the shareholders of the Company should  vote
at the shareholders' meetings held in connection with the Merger.
 
    Based  on the foregoing, we  are of the opinion on  the date hereof that the
IES Ratio, taking into account the IPC Ratio, is fair from a financial point  of
view to the holders of shares of the Company Common Stock.
 
                                          Very truly yours,
                                          MORGAN STANLEY & CO. INCORPORATED
 
                                          By: /s/ ROBERT W. JONES
 
                                             -----------------------------------
                                              Robert W. Jones
                                             Managing Director
 
                                      M-3
<PAGE>
                                                                         ANNEX N
 
Salomon Brothers Inc
 
July 11, 1996
 
Board of Directors
Interstate Power Company
1000 Main Street
Post Office Box 769
Dubuque, IA 52004-0769
Dear Sirs:
 
    You have requested our opinion as to the fairness, from a financial point of
view, to the holders of common stock, par value $3.50 per share ("Company Common
Stock"),  of Interstate Power  Company, a Delaware  corporation (the "Company"),
other than WPL  Holdings, Inc. ("WPL"),  IES Industries Inc.  ("IES") or any  of
their respective affiliates, of the exchange ratio to be used for the conversion
of  Company  Common  Stock  in connection  with  the  proposed  combination (the
"Combination") of the Company, WPL and IES pursuant to the Agreement and Plan of
Merger dated as of  November 10, 1995, as  amended (the "Merger Agreement"),  by
and among WPL, IES, the Company, WPLH Acquisition Co., a wholly owned subsidiary
of  WPL ("Acquisition"), and Interstate Power Company, a wholly owned subsidiary
of the Company and a Wisconsin corporation ("New IPC"). In the Combination,  IES
will merge into WPL, which will be the surviving corporation in the Combination,
and  either (x) Acquisition will merge into  the Company, with the Company to be
the surviving corporation and a  wholly owned subsidiary of  WPL, or (y) in  the
event  certain regulatory requirements mandate  that the utility subsidiaries of
WPL be Wisconsin  corporations, the  Company will merge  into New  IPC and  then
Acquisition  will  merge  into  New  IPC,  with  New  IPC  to  be  the surviving
corporation and a wholly owned subsidiary of WPL. As a result of the  foregoing,
WPL  (which will  change its  name to Interstate  Energy Corporation)  will be a
holding  company  with  three  operating  utilities  as  subsidiaries.  In   the
Combination,  each issued and  outstanding share of  Company Common Stock, other
than shares  owned  by  the  Company,  WPL,  IES  or  any  of  their  respective
subsidiaries,  will be converted into 1.11 shares (the "Company Exchange Ratio")
of common stock, par value of $0.01 per share ("WPL Common Stock"), of WPL. Each
issued and outstanding share of common stock,  no par value, of IES, other  than
shares  owned by IES, WPL, the Company  or any of their respective subsidiaries,
will be  converted into  1.01 shares  of  WPL Common  Stock. We  understand  the
Combination  is  intended to  be  accounted for  as  a pooling  of  interests in
accordance  with  generally  accepted  accounting  principles  as  described  in
Accounting Principles Board Opinion Number 16.
 
    In  arriving  at our  opinion, we  have reviewed  the Merger  Agreement, its
related exhibits and the Joint Proxy Statement/Prospectus dated the date  hereof
and  relating  to  the  Combination.  We  also  have  reviewed  certain publicly
available business and financial  information relating to  the Company, WPL  and
IES,  as  well as  certain other  information, including  financial projections,
provided to us  by the  Company, WPL  and IES. We  have discussed  the past  and
current operations and financial condition and prospects of the Company, WPL and
IES  with their respective senior management. We also have considered such other
information,  financial   studies,  analyses,   investigations  and   financial,
economic,  market and trading  criteria which we  deemed relevant, including the
amended registration statement  on Form S-1  filed by McLeod,  Inc. (a  Delaware
corporation in which IES has a significant ownership interest).
 
    We  have  assumed  and  relied  on  the  accuracy  and  completeness  of the
information reviewed by  us for  the purpose  of this  opinion and  we have  not
assumed  any responsibility for independent  verification of such information or
for independent evaluation  or appraisal of  the assets of  the Company, WPL  or
IES.  With respect to the financial projections  of the Company, WPL and IES, we
have assumed that  they have been  reasonably prepared on  bases reflecting  the
best currently available estimates and
 
                                      N-1
<PAGE>
Board of Directors
Interstate Power Company
Page 2
judgments  of the management of the Company, WPL  or IES, as the case may be, as
to the future financial  performance of such entity,  and we express no  opinion
with respect to such forecasts or the assumptions on which they are based.
 
    Our  opinion is necessarily based upon  business, market, economic and other
conditions as they exist on, and can be evaluated as of, the date of this letter
and does not address  the Company's underlying business  decision to enter  into
the  Combination or constitute a recommendation  to any holder of Company Common
Stock as to how such holder should vote with respect to the Combination. We were
not requested to, and did not, solicit third party offers to acquire all or  any
part  of  the  Company.  Our  opinion as  expressed  below  does  not  imply any
conclusion as to  the likely trading  range for WPL  Common Stock following  the
consummation  of  the  Combination, which  may  vary depending  on,  among other
factors, changes in interest rates,  dividend rates, market conditions,  general
economic  conditions and  other factors  that generally  influence the  price of
securities.
 
    We have acted as financial advisor to the Board of Directors of the  Company
in  connection with the Combination and will receive a fee for our services, the
payment of  a  portion of  which  is contingent  upon  the consummation  of  the
Combination.  Additionally,  we have  acted as  underwriter  for the  Company in
connection with three of its prior financings,  as well as lead manager for  the
initial  public offering by McLeod, Inc. In the ordinary course of our business,
we actively trade the debt and equity securities of the Company, WPL and IES for
our own account and for the accounts  of customers and, accordingly, may at  any
time hold a long or short position in such securities.
 
    Based  upon and subject to the foregoing, it  is our opinion that, as of the
date hereof, the Company Exchange Ratio is  fair from a financial point of  view
to  the holders  of Company Common  Stock (other than  WPL, IES or  any of their
respective affiliates).
 
Very truly yours,
 
Salomon Brothers Inc
 
                                      N-2
<PAGE>
                                                                         ANNEX O
 
                  PROPOSED AMENDMENTS TO THE RESTATED ARTICLES
               OF INCORPORATION OF INTERSTATE ENERGY CORPORATION
 
    Proposed  amendments  reflecting the  Name Change  Amendment and  the Common
Stock Amendment are italicized  and in bold face.  Deletions caused by the  Name
Change Amendment or the Common Stock Amendment are indicated by overstriking.
 
                            ------------------------
 
                                   ARTICLE I
 
    The  name of the corporation is  <#>WPL Holdings, Inc.</#> INTERSTATE ENERGY
CORPORATION.
 
                                   *  *  *  *
 
                                   ARTICLE IV
 
    The corporation shall have authority to issue <#>one</#> TWO hundred million
<#>(100,000,000)</#> (200,000,000) shares of common stock, $.01 par value.
 
                                   *  *  *  *
 
                                      O-1
<PAGE>
                                                                         ANNEX P
 
                      SECTIONS 490.1301 TO 490.1331 OF THE
                         IOWA BUSINESS CORPORATION ACT
                                 DIVISION XIII
                               DISSENTERS' RIGHTS
                                    PART A.
 
    490.1301 DEFINITIONS FOR DIVISION XIII. --  In this division:
 
        1.   "Beneficial shareholder" means the person who is a beneficial owner
    of shares held by a nominee as the record shareholder.
 
        2.  "Corporation"  means the issuer  of the shares  held by a  dissenter
    before  the corporate  action or the  surviving or  acquiring corporation by
    merger or share exchange of that issuer.
 
        3.  "Dissenter"  means a  shareholder who  is entitled  to dissent  from
    corporate  action under section  490.1302 and who  exercises that right when
    and in the manner required by sections 490.1320 through 490.1328.
 
        4.  "Fair value," with respect to a dissenter's shares, means the  value
    of the shares immediately before the effectuation of the corporate action to
    which  the dissenter objects, excluding  any appreciation or depreciation in
    anticipation of the corporate action unless exclusion would be inequitable.
 
        5.  "Interest" means interest from  the effective date of the  corporate
    action  until the date of payment, at the average rate currently paid by the
    corporation on its principal bank loans or, if none, at a rate that is  fair
    and equitable under all the circumstances.
 
        6.    "Record shareholder"  means the  person in  whose name  shares are
    registered in the records of a corporation or the beneficial owner of shares
    to the extent of the rights granted by a nominee certificate on file with  a
    corporation.
 
        7.    "Shareholder"  means  the  record  shareholder  or  the beneficial
    shareholder.
 
    490.1302 SHAREHOLDERS' RIGHT TO DISSENT. --  1. A shareholder is entitled to
dissent from, and obtain payment of  the fair value of the shareholder's  shares
in the event of, any of the following corporate actions:
 
        a.  Consummation of a plan of merger to which the corporation is a party
    if either of the following apply:
 
           (1)  Shareholder  approval  is  required for  the  merger  by section
       490.1103 or the articles of incorporation and the shareholder is entitled
       to vote on the merger.
 
           (2) The corporation is  a subsidiary that is  merged with its  parent
       under section 490.1104.
 
        b.  Consummation of a plan of share exchange to which the corporation is
    a party as the corporation whose shares will be acquired, if the shareholder
    is entitled to vote on the plan.
 
        c.   Consummation of a sale or exchange of all, or substantially all, of
    the property of the corporation other  than in the usual and regular  course
    of business, if the shareholder is entitled to vote on the sale or exchange,
    including  a sale in dissolution, but not including a sale pursuant to court
    order or a sale for  cash pursuant to a plan  by which all or  substantially
    all  of the net proceeds of the sale will be distributed to the shareholders
    within one year after the date of sale.
 
                                      P-1
<PAGE>
        d.  An amendment  of the articles of  incorporation that materially  and
    adversely  affects rights in respect of a dissenter's shares because it does
    any or all of the following:
 
           (1) Alters or abolishes a preferential right of the shares.
 
           (2) Creates, alters or  abolishes a right  in respect of  redemption,
       including  a provision  respecting a sinking  fund for  the redemption or
       repurchase, of the shares.
 
           (3) Alters  or abolishes  a preemptive  right of  the holder  of  the
       shares to acquire shares or other securities.
 
           (4) Excludes or limits the right of the shares to vote on any matter,
       or  to  cumulate  votes,  other than  a  limitation  by  dilution through
       issuance of shares or other securities with similar voting rights.
 
           (5) Reduces  the number  of  shares owned  by  the shareholder  to  a
       fraction  of a share if the fractional share so created is to be acquired
       for cash under section 490.604.
 
           (6) Extends, for the first time after being governed by this chapter,
       the period of duration  of a corporation organized  under chapter 491  or
       496A and existing for a period of years on the day preceding the date the
       corporation is first governed by this chapter.
 
        e.   Any corporate  action taken pursuant  to a shareholder  vote to the
    extent the articles of incorporation, bylaws or a resolution of the board of
    directors provides that  voting or  nonvoting shareholders  are entitled  to
    dissent and obtain payment for their shares.
 
    2.     A  shareholder  entitled  to  dissent  and  obtain  payment  for  the
shareholder's shares  under  this  chapter  is not  entitled  to  challenge  the
corporate  action creating  the shareholder's  entitlement unless  the action is
unlawful or fraudulent with respect to the shareholder or the corporation.
 
    490.1303 DISSENT  BY  NOMINEES  AND  BENEFICIAL OWNERS.  --    1.  A  record
shareholder  may  assert dissenters'  rights  as to  fewer  than all  the shares
registered in  that shareholder's  name only  if the  shareholder dissents  with
respect  to all  shares beneficially  owned by any  one person  and notifies the
corporation in writing of the  name and address of  each person on whose  behalf
the  shareholder asserts dissenters'  rights. The rights  of a partial dissenter
under this  subsection  are  determined  as  if  the  shares  as  to  which  the
shareholder  dissents and the shareholder's other  shares were registered in the
names of different shareholders.
 
    2.  A  beneficial shareholder may  asserts dissenters' rights  as to  shares
held  on  the shareholder's  behalf only  if  the shareholder  does both  of the
following:
 
        a.  Submits to the corporation the record shareholder's written  consent
    to  the dissent not  later than the time  the beneficial shareholder asserts
    dissenters' rights.
 
        b.  Does so with respect to  all shares of which the shareholder is  the
    beneficial  shareholder or over which  that beneficial shareholder has power
    to direct the vote.
 
                                     PART B
 
    490.1320 NOTICE OF DISSENTERS' RIGHTS. --   1. If proposed corporate  action
creating  dissenter's rights under section 490.1302 is  submitted to a vote at a
shareholders' meeting, the meeting  notice must state  that shareholders are  or
may  be entitled to assert dissenters' rights under this part and be accompanied
by a copy of this part.
 
    2.  If corporate action  creating dissenters' rights under section  490.1302
is taken without a vote of shareholders, the corporation shall notify in writing
all shareholders entitled to assert dissenters' rights that the action was taken
and send them the dissenters' notice described in section 490.1322.
 
                                      P-2
<PAGE>
    490.1321  NOTICE OF INTENT TO  DEMAND PAYMENT. --   1. If proposed corporate
action creating dissenters' rights under section 490.1302 is submitted to a vote
at a  shareholders' meeting,  a  shareholder who  wishes to  assert  dissenters'
rights must do all of the following:
 
        a.   Deliver to the corporation before  the vote is taken written notice
    of the shareholder's intent to  demand payment for the shareholder's  shares
    if the proposed action is effectuated.
 
        b.    Not  vote the  dissenting  shareholder's  shares in  favor  of the
    proposed action.
 
    2.  A shareholder who does not  satisfy the requirements of subsection 1  is
not entitled to payment for the shareholder's shares under this part.
 
    490.1322  DISSENTERS' NOTICE. --   1. If  proposed corporate action creating
dissenters' rights  under  section 490.1302  is  authorized at  a  shareholders'
meeting,  the  corporation shall  deliver a  written  dissenters' notice  to all
shareholders who satisfied the requirements of section 490.1321.
 
    2.  The dissenters'  notice must be  sent no later than  ten days after  the
proposed  corporate action is authorized at  a shareholders' meeting, or, if the
corporate action is taken without a vote of the shareholders, no later than  ten
days after the corporate action is taken, and must do all of the following:
 
        a.   State  where the  payment demand  must be  sent and  where and when
    certificates for certificated shares must be deposited.
 
        b.  Inform holders of uncertificated  shares to what extent transfer  of
    the shares will be restricted after the payment demand is received.
 
        c.   Supply a form  for demanding payment that  includes the date of the
    first announcement to  news media  or to shareholders  of the  terms of  the
    proposed corporate action and requires that the person asserting dissenters'
    rights  certify whether or  not the person  acquired beneficial ownership of
    the shares before that date.
 
        d.  Set a date by which the corporation must receive the payment demand,
    which date shall not be fewer than thirty nor more than sixty days after the
    date the dissenters' notice is delivered.
 
        e.  Be accompanied by a copy of this division.
 
    490.1323 DUTY TO  DEMAND PAYMENT. --   1. A  shareholder sent a  dissenters'
notice  described in section  490.1322 must demand  payment, certify whether the
shareholder acquired beneficial ownership of the shares before the date required
to be  set  forth  in  the dissenters'  notice  pursuant  to  section  490.1322,
subsection  2,  paragraph "c,"  and  deposit the  shareholder's  certificates in
accordance with the terms of the notice.
 
    2.   The shareholder  who  demands payment  and deposits  the  shareholder's
shares  under subsection 1 retains all other rights of a shareholder until these
rights are canceled or modified by the taking of the proposed corporate action.
 
    3.  A shareholder who does  not demand payment or deposit the  shareholder's
share  certificates  where required,  each by  the date  set in  the dissenters'
notice, is  not entitled  to payment  for the  shareholder's shares  under  this
division.
 
    490.1324  SHARE  RESTRICTIONS.  --   1.  The  corporation  may  restrict the
transfer of uncertificated shares from the date the demand for their payment  is
received  until  the  proposed corporate  action  is taken  or  the restrictions
released under section 490.1326.
 
    2.  The person for whom dissenters' rights are asserted as to uncertificated
shares retains all other rights of a shareholder until these rights are canceled
or modified by the taking of the proposed corporate action.
 
                                      P-3
<PAGE>
    490.1325 PAYMENT. --  1. Except as provided in section 490.1327, at the time
the proposed corporate  action is taken,  or upon receipt  of a payment  demand,
whichever  occurs later, the  corporation shall pay  each dissenter who complied
with section 490.1323 the amount the corporation estimates to be the fair  value
of the dissenter's shares, plus accrued interest.
 
    2.  The payment must be accompanied by all of the following:
 
        a.   The  corporation's balance  sheet as  of the  end of  a fiscal year
    ending not more than  sixteen months before the  date of payment, an  income
    statement  for that year, a statement of changes in shareholders' equity for
    that year, and the latest available interim financial statements, if any.
 
        b.  A statement of the corporation's  estimate of the fair value of  the
    shares.
 
        c.  An explanation of how the interest was calculated.
 
        d.    A statement  of  the dissenter's  rights  to demand  payment under
    section 490.1328.
 
        e.  A copy of this division.
 
    490.1326 FAILURE TO TAKE ACTION. --  1. If the corporation does not take the
proposed action within sixty days after  the date set for demanding payment  and
depositing  share  certificates,  the  corporation  shall  return  the deposited
certificates and  release the  transfer restrictions  imposed on  uncertificated
shares.
 
    2.    If  after  returning  deposited  certificates  and  releasing transfer
restrictions, the corporation  takes the  proposed action,  it must  send a  new
dissenters'  notice under section 490.1322 as  if the corporate action was taken
without a vote of the shareholders and repeat the payment demand procedure.
 
    490.1327 AFTER-ACQUIRED SHARES. --  1.  A corporation may elect to  withhold
payment  required by section 490.1325 from  a dissenter unless the dissenter was
the beneficial owner of the shares before the date set forth in the  dissenters'
notice as the date of the first announcement to news media or to shareholders of
the terms of the proposed corporate action.
 
    2.    To  the  extent  the  corporation  elects  to  withhold  payment under
subsection 1, after taking the proposed corporate action, it shall estimate  the
fair  value of the shares,  plus accrued interest, and  shall pay this amount to
each dissenter who agrees to accept  it in full satisfaction of the  dissenter's
demand. The corporation shall send with its offer a statement of its estimate of
the fair value of the shares, an explanation of how the interest was calculated,
and  a  statement  of the  dissenter's  right  to demand  payment  under section
490.1328.
 
    490.1328 PROCEDURE IF SHAREHOLDER DISSATISFIED WITH PAYMENT OR OFFER. --  1.
A dissenter  may  notify the  corporation  in  writing of  the  dissenter's  own
estimate of the fair value of the dissenter's shares and amount of interest due,
and  demand payment of the dissenter's  estimate, less any payment under section
490.1325, or reject the  corporation's offer under  section 490.1327 and  demand
payment  of the fair value of the dissenter's shares and interest due, if any of
the following apply:
 
        a.  The dissenter believes that  the amount paid under section  490.1325
    or  offered  under section  490.1327  is less  than  the fair  value  of the
    dissenter's shares or that the interest due is incorrectly calculated.
 
        b.  The corporation fails to make payment under section 490.1325  within
    sixty days after the date set for demanding payment.
 
        c.  The corporation, having failed to take the proposed action, does not
    return  the  deposited  certificates or  release  the  transfer restrictions
    imposed on uncertificated shares  within sixty days after  the date set  for
    demanding payment.
 
                                      P-4
<PAGE>
    2.   A dissenter waives  the dissenter's right to  demand payment under this
section unless the dissenter notifies the corporation of the dissenter's  demand
in  writing under subsection 1 within thirty  days after the corporation made or
offered payment for the dissenter's shares.
 
                                     PART C
 
    490.1330 COURT ACTION. --  1. If a demand for payment under section 490.1328
remains unsettled, the corporation shall commence a proceeding within sixty days
after receiving the payment demand and petition the court to determine the  fair
value  of the shares and accrued interest.  If the corporation does not commence
the proceeding within the  sixty-day period, it shall  pay each dissenter  whose
demand remains unsettled the amount demanded.
 
    2.   The corporation shall commence the  proceeding in the district court of
the county where a corporation's principal office or, if none in this state, its
registered office  is  located. If  the  corporation is  a  foreign  corporation
without  a registered office in this state,  it shall commence the proceeding in
the county in this state where the registered office of the domestic corporation
merged with  or  whose shares  were  acquired  by the  foreign  corporation  was
located.
 
    3.   The corporation shall make all  dissenters, whether or not residents of
this state, whose demands  remain unsettled parties to  the proceeding as in  an
action  against their shares and  all parties must be served  with a copy of the
petition. Nonresidents  may be  served by  registered or  certified mail  or  by
publication as provided by law.
 
    4.  The jurisdiction of the court in which the proceeding is commenced under
subsection 2 is plenary and exclusive. The court may appoint one or more persons
as appraisers to receive evidence and recommend decision on the question of fair
value. The appraisers have the powers described in the order appointing them, or
in any amendment to it. The dissenters are entitled to the same discovery rights
as parties in other civil proceedings.
 
    5.   Each dissenter made  a party to the  proceeding is entitled to judgment
for either of the following:
 
        a.  The amount, if any, by which  the court finds the fair value of  the
    dissenter's   shares,  plus  interest,  exceeds   the  amount  paid  by  the
    corporation.
 
        b.    The  fair  value,  plus  accrued  interest,  of  the   dissenter's
    after-acquired  shares for which the corporation elected to withhold payment
    under section 490.1327.
 
    490.1331 COURT COSTS  AND COUNSEL FEES.  --   1. The court  in an  appraisal
proceeding  commenced under  section 490.1330 shall  determine all  costs of the
proceeding, including  the reasonable  compensation and  expenses of  appraisers
appointed   by  the  court.  The  court  shall  assess  the  costs  against  the
corporation, except that the court may assess  costs against all or some of  the
dissenters,  in amounts the court finds equitable, to the extent the court finds
the dissenters acted arbitrarily, vexatiously, or not in good faith in demanding
payment under section 490.1328.
 
    2.  The court may also assess  the fees and expenses of counsel and  experts
for  the respective parties, in amounts the court finds equitable, for either of
the following:
 
        a.  Against the corporation and in favor of any or all dissenters if the
    court  find  the   corporation  did  not   substantially  comply  with   the
    requirements of sections 490.1320 through 490.1328.
 
        b.  Against either the corporation or a dissenter, in favor of any other
    party,  if the court finds that the party against whom the fees and expenses
    are assessed  acted arbitrarily,  vexatiously,  or not  in good  faith  with
    respect to the rights provided by this chapter.
 
                                      P-5
<PAGE>
    3.   If the court finds that the  services of counsel for any dissenter were
of substantial benefit to other dissenters similarly situated, and that the fees
for those services should not be assessed against the corporation, the court may
award to these counsel reasonable fees to be paid out of the amounts awarded the
dissenters who were benefitted.
 
                                      P-6
<PAGE>
                                                                         ANNEX Q
 
                               SECTION 262 OF THE
                        DELAWARE GENERAL CORPORATION LAW
 
    SECTION262.  APPRAISAL RIGHTS.  (a) Any stockholder of a corporation of this
State who holds shares of stock on the  date of the making of a demand  pursuant
to  subsection (d) of this section with respect to such shares, who continuously
holds such shares through the effective date of the merger or consolidation, who
has otherwise complied with subsection (d)  of this section and who has  neither
voted  in favor of the merger or  consolidation nor consented thereto in writing
pursuant to Section228 of this  title shall be entitled  to an appraisal by  the
Court  of  Chancery  of  the  fair  value  of  his  shares  of  stock  under the
circumstances described in subsections (b) and  (c) of this section. As used  in
this  section, the  word "stockholder" means  a holder  of record of  stock in a
stock corporation and  also a member  of record of  a nonstock corporation;  the
words  "stock" and "share"  mean and include  what is ordinarily  meant by those
words and  also membership  or membership  interest of  a member  of a  nonstock
corporation;  and  the  words  "depository  receipt"  mean  a  receipt  or other
instrument issued  by a  depository  representing an  interest  in one  or  more
shares,  or fractions thereof, solely of stock  of a corporation, which stock is
deposited with the depository.
 
    (b) Appraisal  rights shall  be available  for the  shares of  any class  or
series  of stock of a constituent corporation in a merger or consolidation to be
effected pursuant to Section251, 252, 254, 257, 258, 263 or 264 of this title:
 
        (1) Provided, however, that no appraisal rights under this section shall
    be available for the shares of any class or series of stock, which stock, or
    depository receipts  in  respect  thereof,  at  the  record  date  fixed  to
    determine  the stockholders entitled to receive notice of and to vote at the
    meeting  of  stockholders   to  act   upon  the  agreement   of  merger   or
    consolidation,  were either (i) listed on  a national securities exchange or
    designated as a national market system security on an interdealer  quotation
    system  by the National Association of Securities Dealers, Inc. or (ii) held
    of record by more than 2,000 holders; and further provided that no appraisal
    rights shall  be  available for  any  shares  of stock  of  the  constituent
    corporation  surviving  a  merger if  the  merger  did not  require  for its
    approval the vote of the holders of the surviving corporation as provided in
    subsections (f) or (g) of Section251 of this title.
 
        (2) Notwithstanding paragraph (1)  of this subsection, appraisal  rights
    under  this section shall be available for the shares of any class or series
    of stock of a constituent corporation if the holders thereof are required by
    the  terms  of  an  agreement   of  merger  or  consolidation  pursuant   to
    SectionSection251,  252, 254, 257, 258, 263 and  264 of this title to accept
    for such stock anything except:
 
           a.  Shares of  stock of the corporation  surviving or resulting  from
       such merger or consolidation, or depository receipts in respect thereof;
 
           b.   Shares of stock of any other corporation, or depository receipts
       in respect thereof, which shares of  stock or depository receipts at  the
       effective  date of the merger or consolidation will be either listed on a
       national securities exchange  or designated as  a national market  system
       security  on an interdealer quotation  system by the National Association
       of Securities Dealers, Inc. or held of record by more than 2,000 holders;
 
           c.   Cash  in lieu  of  fractional shares  or  fractional  depository
       receipts  described  in the  foregoing subparagraphs  a.  and b.  of this
       paragraph; or
 
           d.  Any combination of the  shares of stock, depository receipts  and
       cash  in  lieu of  fractional  shares or  fractional  depository receipts
       described in the foregoing subparagraphs a., b. and c. of this paragraph.
 
                                      Q-1
<PAGE>
        (3) In the event all of  the stock of a subsidiary Delaware  corporation
    party  to a merger effected  under Section253 of this  title is not owned by
    the parent corporation  immediately prior  to the  merger, appraisal  rights
    shall be available for the shares of the subsidiary Delaware corporation.
 
    (c)  Any corporation  may provide in  its certificate  of incorporation that
appraisal rights under  this section shall  be available for  the shares of  any
class  or series of its stock as a  result of an amendment to its certificate of
incorporation, any  merger  or  consolidation  in which  the  corporation  is  a
constituent corporation or the sale of all or substantially all of the assets of
the  corporation. If the certificate of incorporation contains such a provision,
the procedures of this section, including those set forth in subsections (d) and
(e) of this section, shall apply as nearly as is practicable.
 
    (d) Appraisal rights shall be perfected as follows:
 
        (1) If a proposed merger or consolidation for which appraisal rights are
    provided under this section is to be submitted for approval at a meeting  of
    stockholders,  the corporation, not less than  20 days prior to the meeting,
    shall notify each of its  stockholders who was such  on the record date  for
    such meeting with respect to shares for which appraisal rights are available
    pursuant  to  subsections  (b)  or  (c)  hereof  that  appraisal  rights are
    available for any or all of the shares of the constituent corporations,  and
    shall  include  in such  notice  a copy  of  this section.  Each stockholder
    electing to  demand  the  appraisal  of his  shares  shall  deliver  to  the
    corporation, before the taking of the vote on the merger or consolidation, a
    written  demand for appraisal of his  shares. Such demand will be sufficient
    if it reasonably informs the corporation of the identity of the  stockholder
    and  that the  stockholder intends  thereby to  demand the  appraisal of his
    shares. A  proxy or  vote  against the  merger  or consolidation  shall  not
    constitute such a demand. A stockholder electing to take such action must do
    so by a separate written demand as herein provided. Within 10 days after the
    effective  date of such merger or  consolidation, the surviving or resulting
    corporation shall notify  each stockholder of  each constituent  corporation
    who  has complied  with this  subsection and  has not  voted in  favor of or
    consented to the  merger or  consolidation of the  date that  the merger  or
    consolidation has become effective; or
 
        (2)  If the merger or consolidation  was approved pursuant to Section228
    or 253 of this title, the surviving or resulting corporation, either  before
    the  effective  date  of  the  merger or  consolidation  or  within  10 days
    thereafter, shall  notify each  of the  stockholders entitled  to  appraisal
    rights  of  the  effective date  of  the  merger or  consolidation  and that
    appraisal rights  are  available  for  any  or all  of  the  shares  of  the
    constituent  corporation, and  shall include in  such notice a  copy of this
    section. The notice shall  be sent by certified  or registered mail,  return
    receipt requested, addressed to the stockholder at his address as it appears
    on  the records  of the corporation.  Any stockholder  entitled to appraisal
    rights may, within 20 days after the  date of mailing of the notice,  demand
    in  writing from the surviving or resulting corporation the appraisal of his
    shares. Such  demand  will  be  sufficient  if  it  reasonably  informs  the
    corporation  of the  identity of  the stockholder  and that  the stockholder
    intends thereby to demand the appraisal of his shares.
 
    (e) Within 120 days after the effective date of the merger or consolidation,
the surviving or resulting corporation or any stockholder who has complied  with
subsections  (a)  and (d)  hereof  and who  is  otherwise entitled  to appraisal
rights, may file a petition in  the Court of Chancery demanding a  determination
of  the  value  of  the  stock of  all  such  stockholders.  Notwithstanding the
foregoing, at any time within 60 days after the effective date of the merger  or
consolidation,  any stockholder shall have the  right to withdraw his demand for
appraisal and to  accept the  terms offered  upon the  merger or  consolidation.
Within  120 days after  the effective date  of the merger  or consolidation, any
stockholder who has complied  with the requirements of  subsections (a) and  (d)
hereof,  upon written request, shall be entitled to receive from the corporation
surviving the merger  or resulting  from the consolidation  a statement  setting
forth  the  aggregate number  of  shares not  voted in  favor  of the  merger or
consolidation and with respect to which demands for appraisal have been received
and the aggregate number of holders of such shares. Such written statement shall
be mailed to the stockholder within 10 days after
 
                                      Q-2
<PAGE>
his written  request  for such  a  statement is  received  by the  surviving  or
resulting  corporation  or within  10 days  after expiration  of the  period for
delivery of  demands for  appraisal under  subsection (d)  hereof, whichever  is
later.
 
    (f) Upon the filing of any such petition by a stockholder, service of a copy
thereof  shall be made upon the  surviving or resulting corporation, which shall
within 20 days after such service file in the office of the Register in Chancery
in which the petition was  filed a duly verified  list containing the names  and
addresses  of all  stockholders who have  demanded payment for  their shares and
with whom agreements as to  the value of their shares  have not been reached  by
the  surviving or resulting corporation.  If the petition shall  be filed by the
surviving or resulting corporation, the petition shall be accompanied by such  a
duly  verified list. The Register in Chancery, if so ordered by the Court, shall
give notice of  the time and  place fixed for  the hearing of  such petition  by
registered  or certified mail  to the surviving or  resulting corporation and to
the stockholders shown on the list at the addresses therein stated. Such  notice
shall  also be given by 1 or more publications at least 1 week before the day of
the hearing, in  a newspaper  of general circulation  published in  the City  of
Wilmington, Delaware or such publication as the Court deems advisable. The forms
of  the notices by mail  and by publication shall be  approved by the Court, and
the costs thereof shall be borne by the surviving or resulting corporation.
 
    (g) At  the  hearing  on  such  petition,  the  Court  shall  determine  the
stockholders who have complied with this section and who have become entitled to
appraisal  rights. The Court  may require the stockholders  who have demanded an
appraisal for their  shares and who  hold stock represented  by certificates  to
submit  their certificates  of stock  to the  Register in  Chancery for notation
thereon of the  pendency of the  appraisal proceedings; and  if any  stockholder
fails to comply with such direction, the Court may dismiss the proceedings as to
such stockholder.
 
    (h)  After determining the stockholders entitled  to an appraisal, the Court
shall appraise the shares, determining their fair value exclusive of any element
of value  arising  from the  accomplishment  or  expectation of  the  merger  or
consolidation,  together with a fair  rate of interest, if  any, to be paid upon
the amount determined to be the fair value. In determining such fair value,  the
Court shall take into account all relevant factors. In determining the fair rate
of  interest, the Court may consider all relevant factors, including the rate of
interest which the surviving or resulting  corporation would have had to pay  to
borrow  money during  the pendency  of the  proceeding. Upon  application by the
surviving or resulting corporation or by any stockholder entitled to participate
in the appraisal proceeding, the Court may, in its discretion, permit  discovery
or  other pretrial proceedings and may proceed to trial upon the appraisal prior
to the final  determination of  the stockholder  entitled to  an appraisal.  Any
stockholder  whose name appears on the list  filed by the surviving or resulting
corporation pursuant to subsection (f) of this section and who has submitted his
certificates of stock  to the  Register in Chancery,  if such  is required,  may
participate  fully in all proceedings until it  is finally determined that he is
not entitled to appraisal rights under this section.
 
    (i) The Court  shall direct the  payment of  the fair value  of the  shares,
together with interest, if any, by the surviving or resulting corporation to the
stockholders  entitled thereto. Interest may be simple or compound, as the Court
may direct. Payment shall be  so made to each such  stockholder, in the case  of
holders  of uncertificated stock forthwith, and in the case of holders of shares
represented by  certificates  upon  the  surrender to  the  corporation  of  the
certificates  representing such  stock. The  Court's decree  may be  enforced as
other decrees in the Court of  Chancery may be enforced, whether such  surviving
or resulting corporation be a corporation of this State or of any state.
 
    (j)   The costs of  the proceeding may be determined  by the Court and taxed
upon the  parties  as the  Court  deems  equitable in  the  circumstances.  Upon
application  of  a stockholder,  the Court  may order  all or  a portion  of the
expenses  incurred  by  any  stockholder   in  connection  with  the   appraisal
proceeding,  including, without  limitation, reasonable attorney's  fees and the
fees and expenses of experts,  to be charged pro rata  against the value of  all
the shares entitled to an appraisal.
 
                                      Q-3
<PAGE>
    (k)  From and after  the effective date  of the merger  or consolidation, no
stockholder who has demanded his appraisal rights as provided in subsection  (d)
of  this section  shall be  entitled to vote  such stock  for any  purpose or to
receive payment  of  dividends  or  other distributions  on  the  stock  (except
dividends  or other  distributions payable to  stockholders of record  at a date
which is prior to the effective date of the merger or consolidation);  provided,
however,  that if no  petition for an  appraisal shall be  filed within the time
provided in subsection (e) of this section, or if such stockholder shall deliver
to the surviving or resulting corporation a written withdrawal of his demand for
an appraisal and an acceptance of the merger or consolidation, either within  60
days  after the  effective date  of the merger  or consolidation  as provided in
subsection (e) of this  section or thereafter with  the written approval of  the
corporation,  then the  right of such  stockholder to an  appraisal shall cease.
Notwithstanding the foregoing, no appraisal proceeding in the Court of  Chancery
shall  be dismissed as to any stockholder without the approval of the Court, and
such approval may be conditioned upon such terms as the Court deems just.
 
    (l) The shares of the surviving or resulting corporation to which the shares
of such objecting stockholders  would have been converted  had they assented  to
the  merger or  consolidation shall have  the status of  authorized and unissued
shares of the surviving  or resulting corporation. (Last  amended by Ch. 79,  L.
'95, eff. 7-1-95.)
 
                                      Q-4
<PAGE>
                                                                         ANNEX R
 
                 PROPOSED AMENDMENT TO RESTATED CERTIFICATE OF
                INCORPORATION OF INTERSTATE POWER COMPANY (IPC)
 
    RESOLVED, that the Restated Certificate of Incorporation of Interstate Power
Company  be amended by deleting Heading C and Paragraph XII of Article FOURTH in
their entirety  and  inserting in  lieu  thereof  the following  Heading  C  and
Paragraph XII:
 
                          "C. Voting Rights of Common
                  Stock and Preferred Stock -- Certain Voting
                         Rights of Preferred Stock and
                        Preference Stock as to Directors
 
    XII.  Except as otherwise required by the  statutes of the State of Delaware
and as otherwise provided in this Article FOURTH, and subject to the  provisions
of the By-Laws of the Corporation, as from time to time amended, with respect to
the  closing of  the transfer  books and  the fixing  of a  record date  for the
determination of stockholders entitled to vote, the holders of the Common  Stock
and  the  Preferred Stock  shall exclusively  possess all  voting power  for the
election of  directors  and for  all  other purposes,  and  the holders  of  the
Preference  Stock shall have  no voting power  and shall not  be entitled to any
notice of or to attend any meeting of stockholders. Except as otherwise required
by the statutes  of the  State of  Delaware and  as otherwise  provided in  this
Article FOURTH, the holders of the Preferred Stock and the holders of the Common
Stock  shall vote together  as one class on  all matters submitted  to a vote of
stockholders of the  Corporation, with each  share of Preferred  Stock and  each
share of Common Stock being entitled to one vote. Notwithstanding the foregoing,
(a)  if and whenever  full cumulative dividends for  four (4) quarterly dividend
periods upon any series of Preferred Stock  shall be unpaid, the holders of  the
Preferred  Stock  as  a class,  subject  to any  rights  of the  holders  of the
Preference Stock, if any, and without  regard to series shall thereafter at  all
elections  of directors have the exclusive right to elect the smallest number of
directors of the Corporation  that shall constitute a  majority of the Board  of
Directors  as  then constituted,  and the  holders  of the  Common Stock  of the
Corporation as a  class shall have  the exclusive right  to elect the  remaining
number  of  directors of  the Corporation,  which  right of  the holders  of the
Preferred Stock, shall however,  cease when full  cumulative dividends upon  the
Preferred  Stock of all series then outstanding shall have been paid or declared
and set apart for payment (and such full cumulative dividends shall be  declared
and  paid out  of any  funds legally  available therefor  as soon  as reasonably
practicable), and/or (b) if and whenever  full cumulative dividends for six  (6)
quarterly  dividend  periods (whether  or not  consecutive)  upon any  series of
Preference Stock shall be unpaid, in whole  or in part, the number of  directors
then  constituting the full Board  of Directors shall be  increased by two (said
two being referred to as the "additional two directors") and the holders of  the
Preference Stock as a class and without regard to series shall thereafter at all
elections  of directors have  the exclusive right to  elect said "additional two
directors" and the holders of  the Common Stock and  the Preferred Stock of  the
Corporation voting as one class, subject to any additional rights of the holders
of  the Preferred  Stock, if any,  shall have  the exclusive right  to elect the
remaining number of directors of the Corporation, which right of the holders  of
the  Preference Stock shall, however, cease  when full cumulative dividends upon
the Preference Stock  of all  series then outstanding  shall have  been paid  or
declared  and set apart for payment (and such full cumulative dividends shall be
declared and  paid  out of  any  funds legally  available  therefor as  soon  as
reasonably practicable).
 
    The  terms of office of all persons  who may be directors of the Corporation
at the time when such right to elect a majority of the directors shall accrue to
holders of Preferred Stock and/or right  to elect such additional two  directors
shall accrue to holders of Preference Stock shall terminate upon the election of
the  successors of such majority directors  and/or such additional two directors
at the next annual meeting of  the stockholders or (unless under the  provisions
of  the By-Laws of the Corporation, as then  in effect, an annual meeting of the
stockholders  is   to   be   held   within   ninety   (90)   days   after   such
 
                                      R-1
<PAGE>
right  to elect  a majority  of directors  and/or such  additional two directors
shall have so accrued) at an earlier special meeting of the stockholders held as
hereinafter  in  this  Paragraph  XII   provided.  A  special  meeting  of   the
stockholders  shall be held at any time after  such right to elect a majority of
the directors shall accrue  to holders of Preferred  Stock and/or such right  to
elect  such two additional directors shall accrue to holders of Preference Stock
upon notice similar to that provided in the By-Laws for an annual meeting, which
notice shall be given not more than fifteen (15) days after the accrual of  such
rights by the President, a Vice-President, or the Secretary, of the Corporation,
such  meeting to be held not less than sixty (60) nor more than ninety (90) days
after the accrual of such rights.
 
    At the  first meeting  of  stockholders held  for  the purpose  of  electing
directors  during  such  time  as  the holders  of  the  Preferred  Stock and/or
Preference Stock shall  have the special  rights voting as  separate classes  to
elect directors, the presence in person or by proxy of the holders of a majority
of  the outstanding  Common Stock, together  with the Preferred  Stock, shall be
required to  constitute  a  quorum  of  each such  class  for  the  election  of
directors,  and the presence in person or by  proxy of the holders of a majority
of the outstanding Preferred Stock and/or Preference Stock shall be required  to
constitute  a quorum of each such class for the election of directors; provided,
however, that in the absence of a  quorum of the holders of the Preferred  Stock
and/or  Preference Stock, no election of directors shall be held, but a majority
of the holders of the Preferred Stock and/or Preference Stock who are present in
person or by proxy shall have power to adjourn the election of the directors  to
a  date not less  than fifteen nor more  than fifty days from  the giving of the
notice of  such  adjourned  meeting  hereinafter  provided  for;  and  provided,
further,  that at such adjourned meeting, the  presence in person or by proxy of
the holders of 35%  of the outstanding Preferred  Stock and/or Preference  Stock
shall  be required to constitute a quorum of each such class for the election of
directors. In  the  event  such  first  meeting  of  stockholders  shall  be  so
adjourned,  it  shall be  the duty  of  the President,  a Vice-President  or the
Secretary of the Corporation, within ten days from the date on which such  first
meeting  shall have been adjourned, to cause notice of such adjourned meeting to
be given to the stockholders entitled to vote thereat, such adjourned meeting to
be held not less than fifteen days nor  more than fifty days from the giving  of
such  second notice. Such  second notice shall  be given in  the form and manner
hereinabove provided for with respect to the notice required to be given of such
first meeting of stockholders, and shall further set forth that a quorum was not
present at such first  meeting and that  the holders of  35% of the  outstanding
Preferred Stock and/or Preference Stock shall be required to constitute a quorum
of  each such class for the election  of directors at such adjourned meeting. If
the requisite quorum of holders of  the Preferred Stock and/or Preference  Stock
shall  not  be present  at said  adjourned  meeting, then  the directors  of the
Corporation then in office shall remain in office until the next annual  meeting
of  the  Corporation,  or  special  meeting  in  lieu  thereof  and  until their
successors shall have been elected and  qualify. Neither such first meeting  nor
such  adjourned meeting  need be held  on a date  within sixty days  of the next
annual meeting of the  Corporation or special meeting  in lieu thereof. At  each
annual  meeting of  the Corporation,  or special  meeting in  lieu thereof, held
during such time as the holders of the Preferred Stock and/or Preference  Stock,
voting  as  separate  classes  shall  have the  right  to  elect  Directors, the
foregoing provisions  of this  paragraph shall  govern each  annual meeting,  or
special  meeting in lieu thereof,  as if said annual  meeting or special meeting
were the  first  meeting  of  stockholders held  for  the  purpose  of  electing
directors  after  the  right  of  the  holders  of  the  Preferred  Stock and/or
Preference Stock, voting as  separate classes, to  elect Directors, should  have
accrued with the exception, that if, at any adjourned annual meeting, or special
meeting  in lieu thereof, the holders of  35% of the outstanding Preferred Stock
and/or Preference Stock are not present in person or by proxy, all the directors
shall be elected by a vote of the holders of a majority of the Common Stock  and
the  Preferred Stock  of the Corporation  present or represented  at the meeting
voting as one class; provided,  however, that notwithstanding the provisions  of
this  paragraph so long as  any shares of the  Preferred Stock and/or Preference
Stock of the Corporation shall be outstanding, the holders of a majority of  the
Preferred  Stock and/or  Preference Stock  shall be  sufficient to  constitute a
quorum of  the  outstanding Preferred  Stock  and/or Preference  Stock  for  the
election of directors.
 
                                      R-2
<PAGE>
    No  delay or failure by the holders of the Preferred Stock and/or Preference
Stock to elect  the members of  the Board  of Directors which  such holders  are
entitled  to elect shall invalidate the election  of the members of the Board of
Directors elected by  the holders of  the Common Stock  and the Preferred  Stock
voting  as one class. Upon  the termination of such right  of the holders of the
Preferred Stock to elect a majority of directors, the terms of office of all the
directors of the Corporation shall terminate upon the election of the successors
of such  directors at  the next  annual meeting  of the  stockholders or  at  an
earlier special meeting of the stockholders called in like manner and subject to
similar  conditions as hereinbefore in this  Paragraph XII provided with respect
to the call of a special meeting  of stockholders for the election of  directors
by the holders of the Preferred Stock.
 
    If  and when all dividends  then in default on  the Preference Stock of each
series then outstanding  shall have  been paid,  the Preference  Stock shall  be
divested  of such voting  powers and the  terms of office  of the additional two
directors (whether elected by vote of the holders of Preference Stock or to fill
a vacancy) shall forthwith  terminate and the  number of directors  constituting
the full Board of Directors shall be reduced accordingly.
 
    Whenever  the Preferred Stock  and/or Preference Stock  shall be entitled to
elect Directors, any holder of such  stock shall have the right, during  regular
business hours, in person or by a duly authorized representative, to examine and
to  make transcripts of the  stock records of the  Corporation for the Preferred
Stock and/or  Preference  Stock for  the  purpose of  communicating  with  other
holders of such stock with respect to the exercise of such right of election."
 
                                   *  *  *  *
 
                                      R-3
<PAGE>
                                                                         ANNEX S
 
INDEPENDENT AUDITORS' REPORT
 
To the Board of Directors and Stockholders of
Interstate Power Company, a Wisconsin Corporation,
a subsidiary of Interstate Power Company, a Delaware Corporation
Dubuque, Iowa
 
    We  have audited  the accompanying  balance sheet  as of  March 25,  1996 of
Interstate Power Company,  a Wisconsin Corporation,  a subsidiary of  Interstate
Power   Company,  a  Delaware  Corporation.  This  financial  statement  is  the
responsibility of the Company's management. Our responsibility is to express  an
opinion on this financial statement based on our audit.
 
    We  conducted  our  audit  in accordance  with  generally  accepted auditing
standards. Those standards require that we plan and perform the audit to  obtain
reasonable  assurance  about  whether  the balance  sheet  is  free  of material
misstatement. An audit includes examining, on a test basis, evidence  supporting
the  amounts  and  disclosures in  the  balance  sheet. An  audit  also includes
assessing the  accounting  principles used  and  significant estimates  made  by
management,  as well  as evaluating the  overall balance  sheet presentation. We
believe that our audit of the balance sheet provides a reasonable basis for  our
opinion.
 
    In  our  opinion,  such  balance  sheet  presents  fairly,  in  all material
respects, the  financial position  as  of March  25,  1996 of  Interstate  Power
Company,  a Wisconsin Corporation,  a subsidiary of  Interstate Power Company, a
Delaware  Corporation,  in   conformity  with   generally  accepted   accounting
principles.
 
                                          Deloitte & Touche LLP
 
April 3, 1996
Davenport, Iowa
 
                                      S-1
<PAGE>
                            INTERSTATE POWER COMPANY
                           (A WISCONSIN CORPORATION)
                                 BALANCE SHEET
                                 MARCH 25, 1996
 
ASSETS
 
<TABLE>
<S>                                                                                  <C>
Cash...............................................................................  $   1,000
                                                                                     ---------
                                                                                     ---------
 
STOCKHOLDER'S EQUITY
Common stock; par value $.01;
 9,000 shares authorized; 100 shares issued and outstanding........................          1
Additional paid-in capital.........................................................        999
                                                                                     ---------
Total..............................................................................  $   1,000
                                                                                     ---------
                                                                                     ---------
</TABLE>
 
                           SEE NOTE TO BALANCE SHEET
 
                            ------------------------
 
                                      S-2
<PAGE>
                            INTERSTATE POWER COMPANY
                           (A WISCONSIN CORPORATION)
                             NOTE TO BALANCE SHEET
 
ORGANIZATION OF INTERSTATE POWER COMPANY
 
    Interstate Power Company, a Wisconsin corporation ("New IPC"), was formed on
March 25, 1996 for purposes of facilitating the mergers between Interstate Power
Company,  a  Delaware  corporation  ("IPC"),  WPL  Holdings,  Inc.,  a Wisconsin
corporation ("WPLH"), and IES Industries Inc., an Iowa corporation ("IES").  New
IPC  has, and  prior to  the mergers described  below will  have, no operations,
except as contemplated by the Agreement and Plan of Merger, dated as of November
10, 1995, as amended (the "Merger Agreement"), by and among New IPC, IPC,  WPLH,
IES   and  WPLH  Acquisition  Co.,  a  Wisconsin  corporation  and  wholly-owned
subsidiary of WPLH ("Acquisition"). IPC is the sole shareholder of New IPC.  The
principal  executive office of New IPC is  located at 1000 Main Street, Dubuque,
Iowa 52001.
 
    The Merger Agreement provides for  two alternative structures to  consummate
the  mergers of IPC, WPLH and IES. New  IPC will be a participant in the mergers
only under  the second  alternative structure;  which alternative  will only  be
followed  if the parties determine, for reasons relating to Wisconsin regulatory
requirements, that  such structure  is required.  Under the  second  alternative
structure,  the  following events  involving New  IPC will  occur: New  IPC will
acquire certain of the utility assets  currently owned by WPLH; IPC shall  cause
the Articles of Incorporation of New IPC to be amended and restated prior to the
consummation  of the mergers to,  among other things, increase  the par value of
common stock of New IPC  ("New IPC Common Stock") to  $3.50 per share, create  a
class  of preferred  stock, $50.00  par value  per share,  of New  IPC ("New IPC
Preferred Stock") with 2,000,000 authorized  shares and increase the  authorized
shares  of  New  IPC  Common  Stock  to  30,000,000  shares.  In  addition,  the
alternative structure provides for: (i) the merger of IPC with and into New  IPC
pursuant  to which (a) each  outstanding share of common  stock, par value $3.50
per share, of IPC ("IPC Common Stock")  will be canceled and converted into  one
share of New IPC Common Stock and (b) each outstanding share of preferred stock,
par  value $50 per share, of IPC  ("IPC Preferred Stock") (except shares held by
IPC preferred stockholders who perfect dissenters' rights under applicable state
law) will be canceled and  converted into one share  of New IPC Preferred  Stock
with  terms (including dividend rates) and designations under New IPC's Restated
Articles of Incorporation substantially identical to those of the IPC  Preferred
Stock  under IPC's Restated Certificate of Incorporation; and (ii) the merger of
Acquisition with and into New IPC  pursuant to which (a) each outstanding  share
of  New IPC  Common Stock  will be  canceled and  converted into  1.11 shares of
common stock, par value $.01 per share, of Interstate Energy Corporation and (b)
each outstanding share of  New IPC Preferred Stock  will remain outstanding  and
unchanged thereby.
 
                                      S-3
<PAGE>
                                               [ALTERNATE PAGE FOR
                                             WPLH PROXY STATEMENT]
 
                       [MAP OF LOCATION OF WPLH MEETING]
 
                                                                       [LOGO]
<PAGE>
                                        [Alternate Page for IES Proxy Statement]
 
             MAP TO IES INDUSTRIES INC. -- ANNUAL MEETING LOCATION
 
                          [Map of Location of IES Meeting]
 
TAKE  EXIT 24A FROM INTERSTATE  380 AND PROCEED EAST  ON COLLINS ROAD TO COLLINS
PLAZA HOTEL.
 
                                                                       [LOGO]
<PAGE>
                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 20.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
    Pursuant  to  the  provisions  of the  Wisconsin  Business  Corporation Law,
directors  and  officers  of  WPLH  and  New  IPC  are  entitled  to   mandatory
indemnification  from WPLH or New IPC, respectively, against certain liabilities
(which may include liabilities  under the Securities Act  of 1933) and  expenses
(i)  to the extent such officers or directors are successful in the defense of a
proceeding; and (ii)  in proceedings  in which the  director or  officer is  not
successful  in defense  thereof, unless  it is  determined that  the director or
officer breached or failed to perform his or  her duties to WPLH or New IPC,  as
the  case may be, and such breach  or failure constituted: (a) a willful failure
to deal fairly with WPLH or its shareholders or New IPC or its shareholders,  as
the  case may be, in  connection with a matter in  which the director or officer
had a material conflict of interest; (b) a violation of criminal law unless  the
director  or officer had  a reasonable cause  to believe his  or her conduct was
lawful or had no reasonable  cause to believe his  or her conduct was  unlawful;
(c)  a  transaction  from which  the  director  or officer  derived  an improper
personal profit; or  (d) willful misconduct.  Additionally, under the  Wisconsin
Business  Corporation Law,  directors of  WPLH and  New IPC  are not  subject to
personal liability to  WPLH or New  IPC, as  the case may  be, their  respective
shareholders  or  any person  asserting rights  on  behalf thereof,  for certain
breaches or failures to perform any  duty resulting solely from their status  as
directors, except in circumstances paralleling those outlined in (a) through (d)
above.
 
    WPLH's   Bylaws  and  New  IPC's   Bylaws  contain  similar  indemnification
provisions as to their respective officers and directors.
 
    The indemnification  provided by  the  Wisconsin Business  Corporation  Law,
WPLH's Bylaws and New IPC's Bylaws is not exclusive of any other rights to which
a  director or officer of WPLH or New IPC may be entitled. WPLH and New IPC also
carry directors' and officers' liability insurance.
 
    Under Section 8.5  of the  Merger Agreement,  the parties  have agreed  that
Interstate  Energy will (i)  indemnify, defend and hold  harmless to the fullest
extent permitted by applicable law,  the present and former officers,  directors
and  employees of each of the parties  to the Merger Agreement or any subsidiary
against certain liabilities (a) arising out of actions or omissions occurring at
or prior to the Effective Time that are based on or arise out of such service as
an officer, director or employee or (b) that are based on, arise from or pertain
to the  transactions contemplated  by the  Merger Agreement,  and (ii)  maintain
policies  of directors'  and officers' liability  insurance for a  period of six
years after the Effective Time. In addition, to the fullest extent permitted  by
law,  all existing  rights of  indemnification will  continue in  full force and
effect for not  less than six  years from  the Effective Time.  See "The  Merger
Agreement  -- Indemnification" in the Original Joint Proxy Statement/ Prospectus
which forms a part of this Registration Statement.
 
ITEM 21.  EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.
 
    (a)  EXHIBITS.   The exhibits listed in  the accompanying Exhibit Index  are
filed  (except where  otherwise indicated)  as part  of this  Joint Registration
Statement. The  cautionary language  regarding  forward looking  statements  set
forth  on page 47 of the Original Joint Proxy Statement/Prospectus is applicable
to forward  looking  statements contained  in  the exhibits  filed  herewith  or
incorporated by reference herein.
 
    (b)   FINANCIAL STATEMENT  SCHEDULES.  No  financial statement schedules are
required to be filed.
 
    (c)   OPINIONS  OF  FINANCIAL  ADVISORS,  PRESENTATION  OF  ARTHUR  ANDERSEN
ECONOMIC  CONSULTING AND SYNERGY  PRESENTATIONS (PREPARED BY  THE MANAGEMENTS OF
WPLH, IES AND IPC WITH THE ASSISTANCE  OF CONSULTING GROUP).  Reference is  made
to   Annexes  II,   III  and   IV  to   the  Supplement   to  the   Joint  Proxy
Statement/Prospectus  and  to   Annexes  L,  M   and  N  to   the  Joint   Proxy
Statement/Prospectus with
 
                                      II-1
<PAGE>
respect  to the  opinions of financial  advisors. Reference is  made to exhibits
(99.7) and  (99.8) to  this Joint  Registration Statement  with respect  to  the
presentation   of   Arthur  Andersen   Economic   Consulting  and   the  Synergy
Presentations.
 
ITEM 22. UNDERTAKINGS.
 
    (a) Each undersigned Registrant hereby undertakes:
 
        (1) To file, during any period in which offers or sales are being  made,
    a post-effective amendment to this Registration Statement:
 
           (i)  To include  any prospectus required  by Section  10(a)(3) of the
       Securities Act of 1933;
 
           (ii) To reflect in the prospectus  any facts or events arising  after
       the  effective date  of the  Registration Statement  (or the  most recent
       post-effective  amendment  thereof)   which,  individually   or  in   the
       aggregate, represent a fundamental change in the information set forth in
       the  Registration Statement. Notwithstanding  the foregoing, any increase
       or decrease in volume of securities offered (if the total dollar value of
       securities offered would not  exceed that which  was registered) and  any
       deviation  from the  low or  high end  of the  estimated maximum offering
       range may  be  reflected  in  the  form  of  prospectus  filed  with  the
       Commission  pursuant to Rule 424(b) if,  in the aggregate, the changes in
       volume and  price represent  no more  than a  20% change  in the  maximum
       aggregate  offering price set  forth in the  "Calculation of Registration
       Fee" table in the effective Registration Statement;
 
           (iii) To include any material information with respect to the plan of
       distribution not previously  disclosed in the  Registration Statement  or
       any material change to such information in the registration statement.
 
    PROVIDED,  HOWEVER, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if
the Registration  Statement is  on Form  S-3 or  Form S-8,  and the  information
required  to be  included in a  post-effective amendment by  those paragraphs is
contained in periodic reports filed by the Registrant pursuant to Section 13  or
Section  15(d) of the Securities  Exchange Act of 1934  that are incorporated by
reference in the Registration Statement.
 
        (2) That,  for  the  purpose  of determining  any  liability  under  the
    Securities  Act of 1933, each such  post-effective amendment shall be deemed
    to be  a  new Registration  Statement  relating to  the  securities  offered
    therein, and the offering of such securities at that time shall be deemed to
    be the initial bona fide offering thereof.
 
        (3)  To remove from registration by  means of a post-effective amendment
    any  of  the  securities  being  registered  which  remain  unsold  at   the
    termination of the offering.
 
    (b)  Each  undersigned Registrant  hereby undertakes  that, for  purposes of
determining any liability under the Securities  Act of 1933, each filing of  the
Registrant's  annual report  pursuant to Section  13(a) or Section  15(d) of the
Securities Exchange  Act  of 1934  that  is  incorporated by  reference  in  the
Registration  Statement  shall  be deemed  to  be a  new  Registration Statement
relating to the securities offered therein, and the offering of such  securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
    (c)  Each undersigned Registrant hereby undertakes as follows: That prior to
any public  reoffering of  the securities  registered hereunder  through use  of
prospectus  which is part of this Registration Statement, by any person or party
who is deemed to be an underwriter within the meaning of Rule 145(c), the issuer
undertakes that such reoffering prospectus  will contain the information  called
for  by the applicable registration form  with respect to reofferings by persons
who may be deemed underwriters, in addition to the information called for by the
other Items of the applicable form.
 
    (d) Each  Registrant undertakes  that  every prospectus  (i) that  is  filed
pursuant  to paragraph (c) immediately preceding,  or (ii) that purports to meet
the requirements of Section 10(a)(3) of the  Act and is used in connection  with
an  offering of securities  subject to Rule 415,  will be filed as  a part of an
 
                                      II-2
<PAGE>
amendment to  the  Registration  Statement  and will  not  be  used  until  such
amendment  is effective,  and that,  for purposes  of determining  any liability
under the Securities Act  of 1933, each such  post-effective amendment shall  be
deemed  to be  a new Registration  Statement relating to  the securities offered
therein, and the offering of such securities at that time shall be deemed to  be
the initial bona fide offering thereof.
 
    (e)  Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of a
Registrant pursuant to the foregoing  provisions, or otherwise, each  Registrant
has  been advised that in the opinion  of the Securities and Exchange Commission
such indemnification is against  public policy as expressed  in the Act and  is,
therefore,  unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by a Registrant of expenses incurred or
paid by a  director, officer  or controlling person  of such  Registrant in  the
successful  defense  of any  action,  suit or  proceeding)  is asserted  by such
director, officer or controlling person in connection with the securities  being
registered,  each  Registrant will,  unless in  the opinion  of its  counsel the
matter has  been  settled  by  controlling  precedent,  submit  to  a  court  of
appropriate  jurisdiction  the question  whether such  indemnification by  it is
against public policy as expressed in the Act and will be governed by the  final
adjudication of such issue.
 
    (f) Each undersigned Registrant hereby undertakes to respond to requests for
information  that is incorporated  by reference into  the prospectus pursuant to
Items 4, 10(b), 11  or 13 of this  Form, within one business  day of receipt  of
such  request, and  to send  the incorporated documents  by first  class mail or
other equally prompt  means. This  includes information  contained in  documents
filed subsequent to the effective date of the Registration Statement through the
date of responding to the request.
 
    (g)  Each undersigned Registrant  hereby undertakes to supply  by means of a
post-effective amendment  all  information  concerning a  transaction,  and  the
company  being  acquired  involved therein,  that  was  not the  subject  of and
included in the Registration Statement when it became effective.
 
                                      II-3
<PAGE>
                                   SIGNATURES
 
   
    Pursuant  to the requirements of the  Securities Act of 1933, the Registrant
has duly caused this amendment to the Registration Statement to be signed on its
behalf by the undersigned,  thereunto duly authorized, in  the City of  Madison,
State of Wisconsin, on August 21, 1996.
    
 
                                          WPL HOLDINGS, INC.
 
                                          By: /s/ ERROLL B. DAVIS, JR.
 
                                             -----------------------------------
                                              Erroll B. Davis, Jr.
                                              PRESIDENT AND CHIEF EXECUTIVE
                                              OFFICER
 
   
    Pursuant  to the requirements of the  Securities Act of 1933, this amendment
to the Registration Statement has been signed below by the following persons  in
the capacities and on the dates indicated.
    
 
   
<TABLE>
<C>                                            <S>                                        <C>
                    NAME                                         TITLE                             DATE
- ---------------------------------------------  -----------------------------------------  -----------------------
 
          /s/ ERROLL B. DAVIS, JR.
    ------------------------------------       President, Chief Executive Officer and         August 21, 1996
            Erroll B. Davis, Jr.                Director (Principal Executive Officer)
 
            /s/ EDWARD M. GLEASON              Vice President, Treasurer and Corporate
    ------------------------------------        Secretary (Principal Financial and            August 21, 1996
              Edward M. Gleason                 Accounting Officer)
 
              L. David Carley*                 Director                                       August 21, 1996
 
             Rockne G. Flowers*                Director                                       August 21, 1996
 
             Donald R. Haldeman*               Director                                       August 21, 1996
 
             Katharine C. Lyall*               Director                                       August 21, 1996
</TABLE>
    
 
                                      II-4
<PAGE>
   
<TABLE>
<C>                                            <S>                                        <C>
                    NAME                                         TITLE                             DATE
- ---------------------------------------------  -----------------------------------------  -----------------------
 
             Arnold M. Nemirow*                Director                                       August 21, 1996
 
              Milton E. Neshek*                Director                                       August 21, 1996
 
              Henry C. Prange*                 Director                                       August 21, 1996
 
               Judith D. Pyle*                 Director                                       August 21, 1996
 
             Carol T. Toussaint*               Director                                       August 21, 1996
 
      *By:     /s/ ERROLL B. DAVIS, JR.
       ------------------------------
            Erroll B. Davis, Jr.
              ATTORNEY-IN-FACT
</TABLE>
    
 
                                      II-5
<PAGE>
                                   SIGNATURES
 
   
    Pursuant  to the requirements of the  Securities Act of 1933, the Registrant
has duly caused this amendment to the Registration Statement to be signed on its
behalf by the undersigned,  thereunto duly authorized, in  the City of  Dubuque,
State of Iowa, on August 21, 1996.
    
 
                                          INTERSTATE POWER COMPANY
 
                                          By: /s/ MICHAEL R. CHASE
 
                                             -----------------------------------
                                              Michael R. Chase
                                              PRESIDENT
 
   
    Pursuant  to the requirements of the  Securities Act of 1933, this amendment
to the Registration Statement has been signed below by the following persons  in
the capacities and on the dates indicated.
    
 
   
<TABLE>
<C>                                            <S>                                        <C>
                  SIGNATURE                                      TITLE                             DATE
- ---------------------------------------------  -----------------------------------------  -----------------------
 
            /s/ MICHAEL R. CHASE
    ------------------------------------       President (Principal Executive, Financial      August 21, 1996
              Michael R. Chase                  and Accounting Officer)
 
          /s/ WAYNE H. STOPPELMOOR
    ------------------------------------       Director                                       August 21, 1996
            Wayne H. Stoppelmoor
</TABLE>
    
 
                                      II-6
<PAGE>
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
   (2.1)    Agreement and Plan of Merger, dated as of November 10, 1995, as amended, by and among WPL
             Holdings, Inc., IES Industries Inc., Interstate Power Company, WPLH Acquisition Co. and
             Interstate Power Company. [Annex A to the Original Joint Proxy Statement/Prospectus
             contained in this Registration Statement (the "Original Joint Proxy Statement/Prospectus")]
             (REGISTRANTS AGREE TO FURNISH SUPPLEMENTALLY A COPY OF ANY OMITTED SCHEDULE OR EXHIBIT TO
             THE SECURITIES AND EXCHANGE COMMISSION UPON REQUEST)
   (2.2)    Amendment No. 2 to Agreement and Plan of Merger, dated as of August 16, 1996, by and among
             WPL Holdings, Inc., IES Industries Inc., Interstate Power Company, WPLH Acquisition Co. and
             Interstate Power Company. [Annex I to the Supplement to the Original Joint Proxy
             Statement/Prospectus contained in this Registration Statement]
   (2.3)    Plan of Merger, dated as of             , 199 , between WPL Holdings Inc. and IES Industries
             Inc. [Included as Exhibit 1.3 of Annex A to the Original Joint Proxy Statement/Prospectus]
   (2.4)    Option Grantor/Option Holder Stock Option and Trigger Payment Agreement, dated as of November
             10, 1995, by and among WPL Holdings, Inc. and IES Industries Inc. [Annex B to the Original
             Joint Proxy Statement/Prospectus]
   (2.5)    Option Grantor/Option Holder Stock Option and Trigger Payment Agreement, dated as of November
             10, 1995, by and among WPL Holdings, Inc. and Interstate Power Company (IPC). [Annex C to
             the Original Joint Proxy Statement/Prospectus]
   (2.6)    Option Grantor/Option Holder Stock Option and Trigger Payment Agreement, dated as of November
             10, 1995, by and among IES Industries Inc. and WPL Holdings, Inc. [Annex D to the Original
             Joint Proxy Statement/Prospectus]
   (2.7)    Option Grantor/Option Holder Stock Option and Trigger Payment Agreement, dated as of November
             10, 1995, by and among IES Industries Inc. and Interstate Power Company (IPC). [Annex E to
             the Original Joint Proxy Statement/Prospectus]
   (2.8)    Option Grantor/Option Holder Stock Option and Trigger Payment Agreement, dated as of November
             10, 1995, by and among Interstate Power Company (IPC) and WPL Holdings, Inc. [Annex F to the
             Original Joint Proxy Statement/Prospectus]
   (2.9)    Option Grantor/Option Holder Stock Option and Trigger Payment Agreement, dated as of November
             10, 1995, by and among Interstate Power Company (IPC) and IES Industries Inc. [Annex G to
             the Original Joint Proxy Statement/Prospectus]
   (2.10)   Form of Employment Agreement of Lee Liu. [Annex H to the Original Joint Proxy
             Statement/Prospectus]
   (2.11)   Form of Employment Agreement of Erroll B. Davis, Jr. [Annex I to the Original Joint Proxy
             Statement/Prospectus]
   (2.12)   Form of Employment Agreement of Wayne Stoppelmoor. [Annex J to the Original Joint Proxy
             Statement/Prospectus]
   (2.13)   Form of Employment Agreement of Michael Chase. [Annex K to the Original Joint Proxy
             Statement/Prospectus]
</TABLE>
 
                                      E-1
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
   (3.1)    Articles of Incorporation of Interstate Power Company (New IPC). [Incorporated by reference
             to Exhibit (3.1) to the Joint Registration Statement on Form S-4 (Registration No.
             333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (3.2)    Form of Restated Articles of Incorporation of Interstate Power Company (New IPC).
             [Incorporated by reference to Exhibit (3.2) to the Joint Registration Statement on Form S-4
             (Registration No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (3.3)    Bylaws of Interstate Power Company (New IPC). [Incorporated by reference to Exhibit (3.3) to
             the Joint Registration Statement on Form S-4 (Registration No. 333-07931) of WPL Holdings,
             Inc. and Interstate Power Company (New IPC)]
   (3.4)    Form of Amended/New Bylaws of Interstate Power Company (New IPC). [Incorporated by reference
             to Exhibit (3.4) to the Joint Registration Statement on Form S-4 (Registration No.
             333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (4.1)    Restated Articles of Incorporation of WPL Holdings, Inc. [Incorporated by reference to
             Exhibit (4.1) to WPL Holdings, Inc.'s Form S-3 Registration Statement (Registration No.
             33-59972)]
   (4.2)    Form of Articles of Amendment to the Restated Articles of Incorporation of WPL Holdings, Inc.
             providing for an increase in the number of authorized shares of common stock from
             100,000,000 to 200,000,000. [Incorporated by reference to Exhibit (4.2) to the Joint
             Registration Statement on Form S-4 (Registration No. 333-07931) of WPL Holdings, Inc. and
             Interstate Power Company (New IPC)]
   (4.3)    Bylaws of WPL Holdings, Inc. as amended [Incorporated by reference to Exhibit (3B) to WPL
             Holdings, Inc.'s Quarterly Report on Form 10-Q for the quarter ended June 30, 1996]
   (4.4)    Rights Agreement, dated as of February 22, 1989, between WPL Holdings, Inc. and Morgan
             Shareholder Services Trust Company. [Incorporated by reference to Exhibit 4 to WPL Holdings,
             Inc.'s Current Report on Form 8-K, dated February 27, 1989]
   (4.5)    Indenture of Mortgage or Deed of Trust dated August 1, 1941, between Wisconsin Power and
             Light Company and First Wisconsin Trust Company
             (n/k/a Firstar Trust Company) and George B. Luhman, as Trustees. [Incorporated by reference
             to Exhibit 7(a) in File No. 2-6409]
   (4.6)    Supplemental Indenture of Wisconsin Power and Light Company dated January 1, 1948.
             [Incorporated by reference to Second Amended Exhibit 7(b) in File No. 2-7361]
   (4.7)    Supplemental Indenture of Wisconsin Power and Light Company dated September 1, 1948.
             [Incorporated by reference to Amended Exhibit 7(c) in File No. 2-7628]
   (4.8)    Supplemental Indenture of Wisconsin Power and Light Company dated June 1, 1950. [Incorporated
             by reference to Amended Exhibit 7.02 in File No. 2-8462]
   (4.9)    Supplemental Indenture of Wisconsin Power and Light Company dated April 1, 1951.
             [Incorporated by reference to Amended Exhibit 7.02 in File No. 2-8882]
</TABLE>
 
                                      E-2
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
   (4.10)   Supplemental Indenture of Wisconsin Power and Light Company dated April 1, 1952.
             [Incorporated by reference to Second Amended Exhibit 4.03 in File No. 2-9526]
   (4.11)   Supplemental Indenture of Wisconsin Power and Light Company dated September 1, 1953.
             [Incorporated by reference to Amended Exhibit 4.03 in File No. 2-10406]
   (4.12)   Supplemental Indenture of Wisconsin Power and Light Company dated October 1, 1954.
             [Incorporated by reference to Amended Exhibit 2.02 in File No. 2-11130]
   (4.13)   Supplemental Indenture of Wisconsin Power and Light Company dated March 1, 1959.
             [Incorporated by reference to Amended Exhibit 2.02 in File No. 2-14816]
   (4.14)   Supplemental Indenture of Wisconsin Power and Light Company dated May 1, 1962. [Incorporated
             by reference to Amended Exhibit 2.02 in File No. 2-20372]
   (4.15)   Supplemental Indenture of Wisconsin Power and Light Company dated August 1, 1968.
             [Incorporated by reference to Amended Exhibit 2.02 in File No. 2-29738]
   (4.16)   Supplemental Indenture of Wisconsin Power and Light Company dated June 1, 1969. [Incorporated
             by reference to Amended Exhibit 2.02 in File No. 2-32947]
   (4.17)   Supplemental Indenture of Wisconsin Power and Light Company dated October 1, 1970.
             [Incorporated by reference to Amended Exhibit 2.02 in File No. 2-38304]
   (4.18)   Supplemental Indenture of Wisconsin Power and Light Company dated July 1, 1971. [Incorporated
             by reference to Amended Exhibit 2.02 in File No. 2-40802]
   (4.19)   Supplemental Indenture of Wisconsin Power and Light Company dated April 1, 1974.
             [Incorporated by reference to Amended Exhibit 2.02 in File No. 2-50308]
   (4.20)   Supplemental Indenture of Wisconsin Power and Light Company dated December 1, 1975.
             [Incorporated by reference to Exhibit 2.01(a) in File No. 2-57775]
   (4.21)   Supplemental Indenture of Wisconsin Power and Light Company dated May 1, 1976. [Incorporated
             by reference to Amended Exhibit 2.02 in File No. 2-56036]
   (4.22)   Supplemental Indenture of Wisconsin Power and Light Company dated May 15, 1978. [Incorporated
             by reference to Amended Exhibit 2.02 in File No. 2-61439]
   (4.23)   Supplemental Indenture of Wisconsin Power and Light Company dated August 1, 1980.
             [Incorporated by reference to Exhibit 4.02 in File No. 2-70534]
   (4.24)   Supplemental Indenture of Wisconsin Power and Light Company dated January 15, 1981.
             [Incorporated by reference to Amended Exhibit 4.03 in File No. 2-70534]
   (4.25)   Supplemental Indenture of Wisconsin Power and Light Company dated August 1, 1984.
             [Incorporated by reference to Exhibit 4.02 in File No. 33-2579]
   (4.26)   Supplemental Indenture of Wisconsin Power and Light Company dated January 15, 1986.
             [Incorporated by reference to Amended Exhibit 4.03 in File No. 33-2579]
</TABLE>
 
                                      E-3
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
   (4.27)   Supplemental Indenture of Wisconsin Power and Light Company dated June 1, 1986. [Incorporated
             by reference to Amended Exhibit 4.02 in File No. 33-4961]
   (4.28)   Supplemental Indenture of Wisconsin Power and Light Company dated August 1, 1988.
             [Incorporated by reference to Exhibit 4.24 in File No. 33-45726]
   (4.29)   Supplemental Indenture of Wisconsin Power and Light Company dated December 1, 1990.
             [Incorporated by reference to Exhibit 4.25 in File No. 33-45726]
   (4.30)   Supplemental Indenture of Wisconsin Power and Light Company dated September 1, 1991.
             [Incorporated by reference to Exhibit 4.26 in File No. 33-45726]
   (4.31)   Supplemental Indenture of Wisconsin Power and Light Company dated October 1, 1991.
             [Incorporated by reference to Exhibit 4.27 in File No. 33-45726]
   (4.32)   Supplemental Indenture of Wisconsin Power and Light Company dated March 1, 1992.
             [Incorporated by reference to Exhibit 4.1 to Wisconsin Power and Light Company's Current
             Report on Form 8-K, dated March 9, 1992]
   (4.33)   Supplemental Indenture of Wisconsin Power and Light Company dated May 1, 1992. [Incorporated
             by reference to Exhibit 4.1 to Wisconsin Power and Light Company's Current Report on Form
             8-K, dated May 12, 1992]
   (4.34)   Supplemental Indenture of Wisconsin Power and Light Company dated June 1, 1992. [Incorporated
             by reference to Exhibit 4.1 to Wisconsin Power and Light Company's Current Report on Form
             8-K, dated June 29, 1992]
   (4.35)   Supplemental Indenture of Wisconsin Power and Light Company dated July 1, 1992. [Incorporated
             by reference to Exhibit 4.1 to Wisconsin Power and Light Company's Current Report on Form
             8-K, dated July 20, 1992]
   (4.36)*  Indenture of Interstate Power Company to The Chase National Bank of the City of New York and
             Carl E. Buckley, as Trustees, dated as of January 1, 1948. [Incorporated by reference to
             Registration Statement No. 2-7659 under the Securities Act of 1933 as Exhibit 7-A]
   (4.37)*  First Supplemental Indenture of Interstate Power Company to The Chase National Bank of the
             City of New York and Carl E. Buckley, as Trustees, dated as of January 1, 1948.
             [Incorporated by reference to Registration Statement No. 2-7659 under the Securities Act of
             1933 as Exhibit 7-A]
   (4.38)*  Second Supplemental Indenture of Interstate Power Company to The Chase National Bank of the
             City of New York and Carl E. Buckley, as Trustees, dated as of July 1, 1948. [Incorporated
             by reference to Registration Statement No. 2-7659 under the Securities Act of 1933 as
             Exhibit 7-B]
   (4.39)*  Third Supplemental Indenture of Interstate Power Company to The Chase National Bank of the
             City of New York and Carl E. Buckley, as Trustees, dated as of January 1, 1950.
             [Incorporated by reference to Registration Statement No. 2-8427 under the Securities Act of
             1933 as Exhibit 7-BBB]
</TABLE>
 
- ------------------------
*  This  agreement  is currently  an  agreement to  which  IPC (which  is  not a
   Registrant hereunder) is a party. In  the event that the IPC  Reincorporation
   Merger is effected, by operation of such merger this agreement will become an
   agreement  of New IPC (which is a  Registrant hereunder), as successor to IPC
   in the IPC Reincorporation Merger.
 
                                      E-4
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
   (4.40)*  Fourth Supplemental Indenture of Interstate Power Company to The Chase National Bank of the
             City of New York and Carl E. Buckley, as Trustees, dated as of January 1, 1952.
             [Incorporated by reference to Registration Statement No. 2-9481 under the Securities Act of
             1933 as Exhibit 4-FF]
   (4.41)*  Fifth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank and Carl
             E. Buckley, as Trustees, dated as of September 30, 1995. [Incorporated by reference to
             Registration Statement No. 2-13268 under the Securities Act of 1933 as Exhibit 4-F]
   (4.42)*  Sixth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank and
             Arthur F. Henning, as Trustees, dated as of May 1, 1957. [Incorporated by reference to
             Registration Statement No. 2-13268 under the Securities Act of 1933 as Exhibit 4-G]
   (4.43)*  Seventh Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank and
             Arthur F. Henning, as Trustees, dated as of May 1, 1959. [Incorporated by reference to
             Registration Statement No. 2-17732 as Exhibit 4-H]
   (4.44)*  Eighth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank and
             Arthur F. Henning, as Trustees, dated as of May 1, 1961. [Incorporated by reference to
             Registration Statement No. 2-21187 as Exhibit 4-I]
   (4.45)*  Ninth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank and
             Arthur F. Henning, as Trustees, dated as of May 1, 1963. [Incorporated by reference to
             Registration Statement No. 2-23301 as Exhibit 4-J]
   (4.46)*  Tenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank and C.
             F. Ruge, as Trustees, dated as of May 1, 1965. [Incorporated by reference to Registration
             Statement No. 2-26130 as Exhibit 4-K]
   (4.47)*  Eleventh Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of May 1, 1967. [Incorporated
             by reference to Registration Statement No. 2-32133 as Exhibit 2-B-13]
   (4.48)*  Twelfth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of May 1, 1969. [Incorporated
             by reference to Interstate Power Company's Current Report on Form 8-K for the month of May,
             1969 as Exhibit A]
   (4.49)*  Thirteenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of May 1, 1974. [Incorporated
             by reference to Interstate Power Company's Current Report on Form 8-K for the month of May,
             1974 as Exhibit A]
</TABLE>
 
- ------------------------
*  This agreement  is  currently an  agreement  to which  IPC  (which is  not  a
   Registrant  hereunder) is a party. In  the event that the IPC Reincorporation
   Merger is effected, by operation of such merger this agreement will become an
   agreement of New IPC (which is  a Registrant hereunder), as successor to  IPC
   in the IPC Reincorporation Merger.
 
                                      E-5
<PAGE>
   
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
   (4.50)*  Fourteenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of October 15, 1975.
             [Incorporated by reference to Interstate Power Company's Current Report on Form 8-K for the
             month of October, 1975 as Exhibit A]
   (4.51)*  Fifteenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of October 1, 1976.
             [Incorporated by reference to Interstate Power Company's Current Report on Form 8-K for the
             month of October, 1976 as Exhibit A]
   (4.52)*  Sixteenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of September 15, 1977.
             [Incorporated by reference to Interstate Power Company's Annual Report on Form 10-K for the
             year ended December 31, 1977 as Exhibit A]
   (4.53)*  Seventeenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. F. Ruge, as Trustees, dated as of March 15, 1978.
             [Incorporated by reference to Interstate Power Company's Annual Report on Form 10-K for the
             year ended December 31, 1978 as Exhibit A]
   (4.54)*  Eighteenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. J. Heinzelmann, as Trustees, dated as of September 15, 1991.
             [Incorporated by reference to Interstate Power Company's Annual Report on Form 10-K for the
             year ended December 31, 1991 as Exhibit Y]
   (4.55)*  Nineteenth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. J. Heinzelmann, as Trustees, dated as of February 15, 1992.
             [Incorporated by reference to Interstate Power Company's Annual Report on Form 10-K for the
             year ended December 31, 1992 as Exhibit N]
   (4.56)*  Twentieth Supplemental Indenture of Interstate Power Company to The Chase Manhattan Bank
             (National Association) and C. J. Heinzelmann, as Trustees, dated as of May 15, 1993.
             [Incorporated by reference to Registration Statement No. 33-59352 dated as of March 11, 1993
             under the Securities Act of 1933 as Exhibit (4)(u)]
   (5.1)**  Opinion of Foley & Lardner as to the legality of the shares of WPL Holdings, Inc. being
             registered (including consent of counsel).
   (8.1)**  Opinion of Foley & Lardner as to federal income tax matters (including consent of counsel).
   (8.2)**  Opinion of Winthrop, Stimson, Putnam & Roberts as to federal income tax matters (including
             consent of counsel).
   (8.3)**  Opinions of Milbank, Tweed, Hadley & McCloy as to federal income tax matters (including
             consent of counsel).
</TABLE>
    
 
- ------------------------
 *  This  agreement  is currently  an agreement  to  which IPC  (which is  not a
    Registrant hereunder) is a party. In the event that the IPC  Reincorporation
    Merger  is effected, by operation of  such merger this agreement will become
    an agreement of New IPC (which  is a Registrant hereunder), as successor  to
    IPC in the IPC Reincorporation Merger.
   
**  Previously filed with this Registration Statement.
    
 
                                      E-6
<PAGE>
   
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
  (23.1)    Consent of Arthur Andersen LLP, WPL Holdings, Inc.'s independent accountants.
  (23.2)    Consent of Arthur Andersen LLP, IES Industries Inc.'s independent accountants.
  (23.3)    Consent of Deloitte & Touche LLP, Interstate Power Company's (IPC's and New IPC's)
             independent auditors.
  (23.4)    Consent of Foley & Lardner (filed as part of Exhibits (5.1) and (8.1)).
  (23.5)    Consent of Merrill Lynch, Pierce, Fenner & Smith Incorporated, financial advisor to WPL
             Holdings, Inc.
  (23.6)    Consent of Morgan Stanley & Co. Incorporated, financial advisor to IES Industries, Inc.
  (23.7)    Consent of Salomon Brothers Inc, financial advisor to Interstate Power Company (IPC).
  (23.8)    Consent of Winthrop, Stimson, Putnam & Roberts (filed as part of Exhibit (8.2)).
  (23.9)    Consent of Milbank, Tweed, Hadley & McCloy (filed as part of Exhibit (8.3)).
  (23.10)   Consent of Arthur Andersen LLP (relating to Arthur Andersen Economic Consulting).
(24)**      Powers of attorney.
   (99.1)   Form of Proxy for the WPL Holdings, Inc. Annual Meeting of Shareowners. [Incorporated by
             reference to Exhibit (99.1) to the Joint Registration Statement on Form S-4 (Registration
             No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (99.2)   Forms of Proxy for the IES Industries Inc. Annual Meeting of Shareowners. [Incorporated by
             reference to Exhibit (99.2) to the Joint Registration Statement on Form S-4 (Registration
             No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (99.3)   Form of Proxy for the Interstate Power Company (IPC) Annual Meeting of Shareowners.
             [Incorporated by reference to Exhibit (99.3) to the Joint Registration Statement on Form S-4
             (Registration No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (99.4)   Restated Certificate of Incorporation of Interstate Power Company (IPC). [Incorporated by
             reference to Exhibit 3.a to Interstate Power Company's Annual Report on Form 10-K for the
             year ended December 31, 1993]
   (99.5)   Form of Certificate of Amendment to the Restated Certificate of Incorporation of Interstate
             Power Company (IPC) providing voting rights for the shares of preferred stock. [Incorporated
             by reference to Exhibit (99.5) to the Joint Registration Statement on Form S-4 (Registration
             No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
   (99.6)   Bylaws of Interstate Power Company (IPC), as amended. [Incorporated by reference to Exhibit
             (3.2) to Interstate Power Company's Annual Report on Form 10-K for the year ended December
             31, 1995]
</TABLE>
    
 
- ------------------------
   
**  Previously filed with this Registration Statement.
    
 
                                      E-7
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                        DOCUMENT DESCRIPTION
- ----------  ---------------------------------------------------------------------------------------------
<C>         <S>                                                                                            <C>
  (99.7)    Presentation of Arthur Andersen Economic Consulting. (Portions of this exhibit have been
             redacted and are subject to a confidential treatment request filed with the Secretary of the
             Securities and Exchange Commission pursuant to Rule 406 under the Securities Act of 1933, as
             amended. Brackets around the words "REDACTED LANGUAGE" indicate those portions of text that
             have been omitted and filed separately with the Securities and Exchange Commission.)
             [Incorporated by reference to Exhibit (99.7) to the Joint Registration Statement on Form S-4
             (Registration No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company (New IPC)]
  (99.8)    Synergy Presentations (prepared by the managements of WPL Holdings, Inc., IES Industries Inc.
             and Interstate Power Company (IPC) with the assistance of Deloitte & Touche Consulting
             Group). [Incorporated by reference to Exhibit (99.8) to the Joint Registration Statement on
             Form S-4 (Registration No. 333-07931) of WPL Holdings, Inc. and Interstate Power Company
             (New IPC)]
</TABLE>
 
   
                                      E-8
    

<PAGE>
                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement of our reports dated January 26, 1996
included in the WPL Holdings, Inc. Form 10-K for the year ended December 31,
1995 and to all references to our Firm included in this registration statement.



                                   ARTHUR ANDERSEN LLP




   
Milwaukee, Wisconsin,
August 21, 1996
    


<PAGE>

                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement of our reports dated February 2, 1996
included in the IES Industries Inc. Form 10-K for the year ended December 31,
1995 and to all references to our Firm included in this registration statement.



                                   ARTHUR ANDERSEN LLP


   
Chicago, Illinois,
August 21, 1996
    

<PAGE>

INDEPENDENT AUDITORS' CONSENT

   

We consent to the incorporation by reference in this Registration Statement of
WPL Holdings, Inc. and Interstate Power Company, a Wisconsin Corporation, on
Form S-4, Amendment No. 1, of our reports dated January 26, 1996, appearing 
in and incorporated by reference in the Annual Report on Form 10-K of 
Interstate Power Company, a Delaware Corporation, for the year ended 
December 31, 1995 and to the reference to us under the heading "Experts" in 
the Joint Proxy Statement/Prospectus, which is part of this Registration 
Statement.
    

We also consent to the use in this Registration Statement of WPL Holdings, Inc.
and Interstate Power Company, a Wisconsin Corporation, on Form S-4 of our report
dated April 3, 1996 (relating to the balance sheet as of March 25, 1996 of
Interstate Power Company, a Wisconsin Corporation), appearing in Annex S to this
Joint Proxy Statement/Prospectus, which is part of this Registration Statement.




                                   Deloitte & Touche LLP



   
Davenport, Iowa
August 19, 1996
    


<PAGE>

                        CONSENT OF MERRILL LYNCH, PIERCE,
                           FENNER & SMITH INCORPORATED


   
                                  August 21, 1996
    


The Board of Directors
WPL Holdings, Inc.
P.O. Box 2568
Madison, Wisconsin  53701-2568

Dear Members of the Board:
   
          We hereby consent to the use of our opinion letters dated July 11, 
1996 and August 21, 1996, to the Board of Directors of WPL Holdings, Inc. 
("WPL"), included as Annex L to the Joint Proxy Statement/Prospectus and as 
Annex II to the Supplement to the Joint Proxy Statement/Prospectus dated 
August 21, 1996, in each case of WPL, IES Industries Inc. and Interstate 
Power Company, which form a part of the Registration Statement on Form S-4 of 
WPL filed with the Securities and Exchange Commission, and to the references 
therein to such opinion under the captions "Summary," "The Mergers" and 
"Recent Developments."
    
                                   MERRILL LYNCH, PIERCE, FENNER &
                                        SMITH INCORPORATED



                                   By: /s/ William D. Rifkin
                                       --------------------------------
                                        Managing Director

<PAGE>
CONSENT OF MORGAN STANLEY & CO. INCORPORATED

   
August 21, 1996
    


IES Industries Inc.
IES Tower
200 First Street, S.E.
Cedar Rapids, Iowa  52401


Dear Sirs:

     We hereby consent to the inclusion in the Registration Statement of WPL 
Holdings, Inc. ("WPL") and Interstate Power Company, a Wisconsin corporation, 
on Form S-4, relating to the proposed merger of IES Industries Inc., WPL and 
Interstate Power Company, a Delaware corporation, of our opinion letters 
appearing as Annex M to the Proxy Statement/Prospectus and as Annex III to 
the Supplement to Proxy Statement/Prospectus, each of which is a part of the 
Registration Statement, and to the references of our firm name therein.  In 
giving such consent, we do not thereby admit that we come within the category 
of persons whose consent is required under Section 7 of the Securities Act of 
1933, as amended, or the rules and regulations adopted by the Securities and 
Exchange Commission thereunder nor do we admit that we are experts with 
respect to any part of such Registration Statement within the meaning of the 
term "experts" as used in the Securities Act of 1933, as amended, or the 
rules and regulations of the Securities and Exchange Commission thereunder.

                                   Very truly yours,


                                   MORGAN STANLEY & CO. INCORPORATED



                                   By: /s/ Kenneth R. Marks
                                       ---------------------------------



<PAGE>

                        CONSENT OF SALOMON BROTHERS INC
   

     We hereby consent to the use of our name and to the description of our 
opinion letters dated November 10, 1995, July 11, 1996 and August 21, 1996 
under the captions "THE MERGERS -- Opinions of Financial Advisors" and 
"RECENT DEVELOPMENTS -- Opinions of Financial Advisors" in, and to the 
inclusion of our opinion letters dated July 11, 1996 and August 21, 1996, as 
Annexes N and IV to, the Joint Proxy Statement/Prospectus and the Supplement 
to Joint Proxy Statement/Prospectus, respectively, of WPL Holdings, Inc., IES 
Industries Inc. and Interstate Power Company, which Joint Proxy 
Statement/Prospectus and Supplement to Joint Proxy Statement/Prospectus are 
part of the Registration Statement on Form S-4 of WPL Holdings, Inc. By 
giving such consent we do not thereby admit that we are experts with respect 
to any part of such Registration Statement within the meaning of the term 
"expert" as used in, or that we come within the category of persons whose 
consent is required under, the Securities Act of 1933 or the rules and 
regulations of the Securities and Exchange Commission promulgated thereunder.
    

                                          SALOMON BROTHERS INC

                                          By: /s/ Salomon Brothers Inc
                                              ---------------------------

   
New York, New York
August 21, 1996
    



<PAGE>


                         CONSENT OF ARTHUR ANDERSEN LLP

We hereby consent to the use in this registration statement of the reports of 
Arthur Andersen Economic Consulting referred to in "The Mergers -- Background 
of the Mergers" section of the joint proxy statement/prospectus and in the 
"Recent Developments" section of the prospectus supplement included in this 
registration statement and to all references to Arthur Andersen Economic 
Consulting included in this registration statement.

                                                 ARTHUR ANDERSEN LLP

Los Angeles, California
August 22, 1996




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