MARSHALL & ILSLEY CORP/WI/
S-4, 1997-06-06
NATIONAL COMMERCIAL BANKS
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<PAGE>
 
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 6, 1997
 
                                                     REGISTRATION NO. 333-
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
 
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549
 
                               ----------------
 
                                   FORM S-4
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
 
                               ----------------
 
                         MARSHALL & ILSLEY CORPORATION
            (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
       WISCONSIN                     6021                          39-0968604
    (STATE OR OTHER
    JURISDICTION OF
   INCORPORATION OR
     ORGANIZATION)
             (PRIMARY STANDARD INDUSTRIAL CLASSIFICATION CODE NO.)
                                                                    (I.R.S.
                                                                    EMPLOYER
                                                                 IDENTIFICATION
                                                                      NO.)
 
                            770 NORTH WATER STREET
                          MILWAUKEE, WISCONSIN 53202
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
 
                               ----------------
 
                           M.A. HATFIELD, SECRETARY
                         MARSHALL & ILSLEY CORPORATION
                            770 NORTH WATER STREET
                          MILWAUKEE, WISCONSIN 53202
                                (414) 765-7801
(NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)
 
                               ----------------
 
                                  COPIES TO:
 
          RANDALL J. ERICKSON                      PETER C. KRUPP
         GODFREY & KAHN, S.C.,                   FRED B. WHITE, III
        780 NORTH WATER STREET          SKADDEN, ARPS, SLATE, MEAGHER & FLOM
      MILWAUKEE, WISCONSIN 53202                         LLP
            (414) 273-3500                        919 THIRD AVENUE
                                              NEW YORK, NEW YORK 10022
                                                   (212) 735-3000
 
                               ----------------
 
  APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE OF SECURITIES TO THE
PUBLIC: As soon as practicable after the effective date of the Registration
Statement.
 
  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. [_]
 
                        CALCULATION OF REGISTRATION FEE
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                                     PROPOSED       PROPOSED
                                                     MAXIMUM        MAXIMUM
                                       AMOUNT        OFFERING      AGGREGATE      AMOUNT OF
     TITLE OF EACH CLASS OF            TO BE          PRICE         OFFERING     REGISTRATION
   SECURITIES TO BE REGISTERED     REGISTERED(1)    PER SHARE       PRICE(2)      FEE(2)(3)
- ---------------------------------------------------------------------------------------------
<S>                                <C>            <C>            <C>            <C>
Common Stock, $1.00 par value....    12,327,390        N/A        $840,846,460   $139,353.26
- ---------------------------------------------------------------------------------------------
</TABLE>
- -------------------------------------------------------------------------------
(1) The number of shares to be registered is based upon an estimate of the
    maximum number of shares of Common Stock of the Registrant to be issued to
    holders of Common Stock of Security Capital Corporation ("Security")
    pursuant to the Merger Agreement (as defined herein).
(2) The registration fee was computed pursuant to Rule 457(f)(1) under the
    Securities Act of 1933, as amended, based upon the average of the high and
    low prices of shares of Security Common Stock on June 3, 1997 ($92.50)
    reported on the Nasdaq National Market multiplied by the maximum number of
    such shares that may be exchanged for the Common Stock of the Registrant
    being registered (9,090,232), less the amount of cash to be received by
    Security shareholders ($376,335,605).
(3) In accordance with Rule 457(b), the total registration fee of $139,353.26
    has been reduced by $158,624.55, which was previously paid on April 22,
    1997 upon filing under the Securities Exchange Act of 1934, as amended, of
    preliminary copies of proxy materials of Security. Therefore, no
    additional registration fee is payable upon filing of this Registration
    Statement.
 
  THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT
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 THE REGISTRATION STATEMENT
SHALL BECOME EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID
SECTION 8(A), MAY DETERMINE.
 
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
<PAGE>
 
 
                                    [LOGO]
 
 
                         SECURITY CAPITAL CORPORATION
                           184 WEST WISCONSIN AVENUE
                          MILWAUKEE, WISCONSIN 53203
                                (414) 273-8090
 
                                                                   June 6, 1997
 
Dear Holder of Security Capital Corporation Common Stock:
 
  You are cordially invited to attend a Special Meeting of the Shareholders
(the "Special Meeting") of Security Capital Corporation ("Security") to be
held on Wednesday, July 9, 1997 at 10:00 a.m., Milwaukee time at The Grand
Milwaukee Hotel, Grand Ballroom East, 4747 South Howell Avenue, Milwaukee,
Wisconsin.
 
  At this Special Meeting, you will be asked to approve the merger (the
"Merger") of Security with and into Marshall & Ilsley Corporation ("M&I"). As
a result of the Merger, holders of Security common stock will have the right
to convert their shares into cash, M&I common stock or a combination of cash
and M&I common stock subject to the election and allocation procedures
described in the attached Proxy Statement-Prospectus. The actual number of
shares of M&I common stock and the amount of cash will be determined based on
a formula set forth in the Agreement and Plan of Merger, which takes into
consideration (i) the average of the bid and asked prices per share of M&I
common stock as reported by the Nasdaq National Market for the ten trading
days ending on the fifth calendar day immediately prior to the anticipated
effective date of the Merger and (ii) the total number of shares of Security
common stock outstanding.
 
  If you elect to receive a combination of M&I common stock and cash, you will
receive approximately 1.3561 shares of M&I common stock and approximately
$41.40 in cash for each share of Security common stock. Based on the closing
price of M&I common stock on March 14, 1997 of $37.3125 per share, the
combined value of such cash and M&I common stock would be $92 per share of
Security common stock. Based on the closing price of M&I common stock on March
14, 1997 of $37.3125 per share, a holder of Security Common Stock receiving
all stock would receive approximately 2.4657 shares of M&I Common Stock per
share of Security Common Stock for a value of $92 per share, and a holder of
Security Common Stock receiving all cash would receive approximately $92 in
cash per share of Security Common Stock subject to the allocation procedures
applicable to oversubscriptions of M&I common stock or cash.
 
  A table giving examples of the results of various possible elections by a
holder of Security common stock based on different average prices of M&I
common stock appears at page 13 and is attached as Appendix B to the Proxy
Statement-Prospectus. REGARDLESS OF WHICH ELECTION YOU MAKE, THE TOTAL VALUE
OF THE CONSIDERATION YOU RECEIVE WILL BE THE SAME (BASED, IN THE CASE OF
ELECTIONS INCLUDING M&I COMMON STOCK, ON THE AVERAGE PRICE OF M&I COMMON STOCK
AS DESCRIBED ABOVE).
 
  THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT YOU VOTE FOR THE APPROVAL
OF THE AGREEMENT AND PLAN OF MERGER AND THE TRANSACTIONS CONTEMPLATED THEREBY.
 
  The proposed Merger requires regulatory approvals and the approval of the
Agreement and Plan of Merger by the holders of a majority of the outstanding
shares of common stock of Security. Please carefully review and consider the
enclosed Proxy Statement-Prospectus which explains the proposed Merger in
detail.
 
  IT IS IMPORTANT THAT YOUR SHARES ARE REPRESENTED AT THE MEETING, WHETHER OR
NOT YOU PLAN TO ATTEND THE MEETING. AN ABSTENTION OR FAILURE TO VOTE WILL HAVE
THE SAME EFFECT AS A VOTE AGAINST THE MERGER. ACCORDINGLY, PLEASE COMPLETE,
DATE, SIGN AND RETURN PROMPTLY YOUR PROXY CARD IN THE ENCLOSED ENVELOPE. YOU
MAY ATTEND THE MEETING AND VOTE YOUR SHARES IN PERSON IF YOU WISH, EVEN THOUGH
YOU HAVE PREVIOUSLY RETURNED YOUR PROXY.
 
  THE NOTICE OF MEETING AND PROXY STATEMENT-PROSPECTUS DESCRIBING THESE
IMPORTANT MATTERS ARE ATTACHED. If you require assistance in completing your
proxy card or have questions about voting procedures or the Proxy Statement-
Prospectus, please feel free to contact Roger D. Kamin, Senior Vice President,
Chief Financial Officer and Secretary-Treasurer, at (414) 277-6484.
 
                                          In all sincerity,
 
                                          Wm. G. Schuett, Sr.
                                          President and Chief Executive
                                           Officer
<PAGE>
 
                         SECURITY CAPITAL CORPORATION
                           184 WEST WISCONSIN AVENUE
                          MILWAUKEE, WISCONSIN 53203
                                (414) 273-8090
 
                               ----------------
 
                   NOTICE OF SPECIAL MEETING OF SHAREHOLDERS
                          TO BE HELD ON JULY 9, 1997
 
                               ----------------
 
                                                                   June 6, 1997
 
To the Holders of Common Stock of Security Capital Corporation:
 
  NOTICE IS HEREBY GIVEN that a Special Meeting of Shareholders (the "Special
Meeting") of Security Capital Corporation ("Security") will be held on
Wednesday, July 9, 1997 at 10:00 a.m., Milwaukee time, at The Grand Milwaukee
Hotel, Grand Ballroom East, 4747 South Howell Avenue, Milwaukee, Wisconsin.
 
  The Special Meeting is for the purpose of considering and voting upon the
following matters, all of which are set forth more completely in the
accompanying Proxy Statement-Prospectus.
 
    (1) To approve and adopt the Agreement and Plan of Merger (the "Merger
  Agreement"), dated as of March 14, 1997, between Security and Marshall &
  Ilsley Corporation ("M&I"), the merger of Security with and into M&I (the
  "Merger") and the transactions contemplated thereby. Pursuant to the Merger
  each outstanding share of common stock, par value $1.00, of Security will
  be converted into either a combination of M&I common stock and cash, shares
  of M&I common stock, or cash, as more fully described in the accompanying
  Proxy Statement-Prospectus; and
 
    (2) Such other matters as may properly come before the Special Meeting or
  any adjournment or postponements thereof.
 
  Security has established June 4, 1997, as the record date for the
determination of shareholders entitled to notice of and to vote at the Special
Meeting and any adjournments or postponements thereof. Only shareholders of
record as of the close of business on that date will be entitled to vote at
the Special Meeting or any adjournments or postponements thereof. In the event
there are not sufficient votes for a quorum or to approve or ratify the
foregoing proposal at the time of the Special Meeting, the Special Meeting may
be adjourned or postponed in order to permit further solicitation of proxies
by Security.
 
  Approval and adoption of the Merger Agreement, the Merger and the
transactions contemplated thereby require the affirmative vote of a majority
of the outstanding shares of Security common stock entitled to vote at the
Special Meeting. PLEASE SIGN AND PROMPTLY RETURN THE PROXY CARD IN THE
ENCLOSED ENVELOPE, WHETHER OR NOT YOU EXPECT TO ATTEND THE SPECIAL MEETING.
FAILURE TO RETURN A PROPERLY EXECUTED PROXY CARD OR TO VOTE AT THE SPECIAL
MEETING WILL HAVE THE SAME EFFECT, IN MOST CASES, AS A VOTE AGAINST THE
MERGER.
 
  THE SECURITY BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT SHAREHOLDERS
VOTE FOR THE PROPOSAL TO APPROVE AND ADOPT THE MERGER AGREEMENT, THE MERGER
AND THE TRANSACTIONS CONTEMPLATED THEREBY, WHICH ARE DESCRIBED IN THE
ACCOMPANYING PROXY STATEMENT-PROSPECTUS.
 
                                          By Order of the Board of Directors,
 
                                          Roger D. Kamin
                                          Senior Vice President, Chief
                                           Financial Officer and
                                          Secretary-Treasurer
 
Milwaukee, Wisconsin
June 6, 1997
 
 YOU ARE CORDIALLY INVITED TO ATTEND THE SPECIAL MEETING. YOUR VOTE IS
 IMPORTANT. WHETHER OR NOT YOU PLAN TO ATTEND THE SPECIAL MEETING, PLEASE
 MARK, SIGN, DATE AND RETURN THE ENCLOSED PROXY FORM PROMPTLY IN THE ENVELOPE
 PROVIDED.
 
<PAGE>
 
                         SECURITY CAPITAL CORPORATION
                                PROXY STATEMENT
        FOR SPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON JULY 9, 1997
 
                         MARSHALL & ILSLEY CORPORATION
                                  PROSPECTUS
 
  This Proxy Statement-Prospectus is being furnished to the shareholders of
Security Capital Corporation ("Security"), a Wisconsin corporation, in
connection with the solicitation of proxies by the Board of Directors of
Security for use at the Special Meeting of Shareholders (the "Special
Meeting") of Security to be held on July 9, 1997, including any adjournment or
postponement of such Special Meeting.
 
  At the Special Meeting, shareholders of Security will vote upon a proposal
to approve and adopt the Agreement and Plan of Merger, dated as of March 14,
1997, between Marshall & Ilsley Corporation ("M&I") and Security (the "Merger
Agreement"), the merger of Security with and into M&I (the "Merger") and the
transactions contemplated thereby.
 
  This Proxy Statement-Prospectus also constitutes the Prospectus of M&I with
respect to 12,327,390 shares of M&I common stock, $1.00 par value (the "M&I
Common Stock"), to be issued in connection with the Merger, subject to
adjustment as set forth in the Merger Agreement. Upon consummation of the
Merger, each then outstanding share of Security common stock, $1.00 par value
(the "Security Common Stock"), will be converted, subject to the election and
allocation procedures described in this Proxy Statement-Prospectus, into one
of the following: (x) approximately $41.40 in cash and approximately 1.3561
shares of M&I Common Stock, (y) a number of shares of M&I Common Stock equal
to the Average Per Share Consideration, or (z) an amount of cash, without
interest, equal to the Average Per Share Consideration. The Average Per Share
Consideration will be determined based on the average of the average final bid
and asked quotations for M&I Common Stock (the "Valuation Period Market
Value") as reported on the National Association of Securities Dealers
Automated Quotation/National Market System (the "Nasdaq National Market")
during the ten (10) consecutive trading-day period ending on the fifth
calendar day prior to the Effective Time (the "Valuation Period").
 
  Based on the closing price on the Nasdaq National Market of M&I Common Stock
on March 14, 1997 of $37.3125 per share, a holder of Security Common Stock
electing to receive a combination of cash and stock would receive $41.40 in
cash and 1.3561 shares of M&I Common Stock per share of Security Common Stock,
and subject to oversubscription allocations, a holder of Security Common Stock
receiving all stock would receive approximately 2.4657 shares of M&I Common
Stock per share of Security Common Stock with a Valuation Period Market Value
equal to the same $92 per share of Security Common Stock, and a holder of
Security Common Stock receiving all cash would receive $92 in cash per share
of Security Common Stock. THE MARKET VALUE OF M&I COMMON STOCK RECEIVED AND/OR
THE AMOUNT OF CASH RECEIVED PER SHARE OF SECURITY COMMON STOCK IN THE MERGER
WILL VARY WITH THE PRICE OF M&I COMMON STOCK. PAGE 13 AND APPENDIX B TO THIS
PROXY STATEMENT-PROSPECTUS SET FORTH THE AMOUNT OF CASH AND THE NUMBER OF
SHARES OF M&I COMMON STOCK TO BE ISSUED IN THE MERGER PER SHARE OF SECURITY
COMMON STOCK BASED ON VARIOUS ASSUMED VALUATION PERIOD MARKET VALUES AND AN
ASSUMED TOTAL NUMBER OF SHARES OF SECURITY COMMON STOCK OUTSTANDING ON THE
LAST DAY OF THE VALUATION PERIOD.
 
  This Proxy Statement-Prospectus is first being mailed to Security
shareholders on or about June 10, 1997.
 
   M&I COMMON STOCK IS QUOTED UNDER THE SYMBOL "MRIS" ON THE NASDAQ NATIONAL
                                    MARKET.
 
                               ----------------
 THE  ABOVE  MATTERS  ARE  DISCUSSED  IN  DETAIL  IN  THIS  PROXY  STATEMENT-
   PROSPECTUS. THE PROPOSED  MERGER IS A  COMPLEX TRANSACTION. SHAREHOLDERS
     ARE  STRONGLY  URGED  TO  READ  AND  CONSIDER  CAREFULLY  THIS  PROXY
      STATEMENT-PROSPECTUS IN ITS ENTIRETY.
 
  SHARES OF M&I COMMON STOCK OFFERED HEREBY HAVE NOT BEEN APPROVED OR DISAP-
    PROVED BY THE SECURITIES AND EXCHANGE COMMISSION OR BY ANY STATE SECU-
      RITIES COMMISSION NOR  HAS THE SECURITIES  AND EXCHANGE COMMISSION
        OR ANY STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY OR
          ADEQUACY  OF THIS  PROXY STATEMENT-PROSPECTUS.  ANY REPRE-
            SENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
 
                               ----------------
  THE SHARES OF  M&I COMMON STOCK  OFFERED HEREBY ARE  NOT DEPOSITS,  SAVINGS
    ACCOUNTS OR OTHER OBLIGATIONS OF A BANK OR SAVINGS ASSOCIATION AND  ARE
      NOT INSURED BY  THE FEDERAL  DEPOSIT INSURANCE  CORPORATION OR  ANY
        OTHER GOVERNMENTAL AGENCY OR INSTRUMENTALITY.
 
                               ----------------
         The date of this Proxy Statement-Prospectus is June 6, 1997.
<PAGE>
 
  NO PERSONS HAVE BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS OTHER THAN THOSE CONTAINED IN THIS PROXY STATEMENT-PROSPECTUS
OR INCORPORATED BY REFERENCE HEREIN IN CONNECTION WITH THE SOLICITATION OF
PROXIES OR THE OFFERING OF SECURITIES MADE HEREBY AND, IF GIVEN OR MADE, SUCH
INFORMATION OR REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN
AUTHORIZED BY M&I OR SECURITY. THIS PROXY STATEMENT-PROSPECTUS DOES NOT
CONSTITUTE AN OFFER TO SELL, OR A SOLICITATION OF AN OFFER TO BUY, ANY
SECURITIES, OR THE SOLICITATION OF A PROXY, IN ANY JURISDICTION TO OR FROM ANY
PERSON TO WHOM IT IS NOT LAWFUL TO MAKE ANY SUCH OFFER OR SOLICITATION IN SUCH
JURISDICTION. NEITHER THE DELIVERY OF THIS PROXY STATEMENT-PROSPECTUS NOR ANY
DISTRIBUTION OF SECURITIES MADE HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES,
CREATE AN IMPLICATION THAT THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF M&I OR
SECURITY SINCE THE DATE OF THIS PROXY STATEMENT-PROSPECTUS OR THAT THE
INFORMATION HEREIN OR THE DOCUMENTS OR REPORTS INCORPORATED BY REFERENCE
HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO SUCH DATE. ALL INFORMATION
CONTAINED IN THIS PROXY STATEMENT-PROSPECTUS RELATING TO M&I AND ITS
SUBSIDIARIES HAS BEEN SUPPLIED BY M&I, AND ALL INFORMATION CONTAINED IN THIS
PROXY STATEMENT-PROSPECTUS RELATING TO SECURITY AND ITS SUBSIDIARIES HAS BEEN
SUPPLIED BY SECURITY.
 
                             AVAILABLE INFORMATION
 
  Both M&I and Security are subject to the informational requirements of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and, in
accordance with the Exchange Act, file reports, proxy statements and other
information with the Securities and Exchange Commission (the "Commission").
Such reports, proxy statements and other information can be inspected and
copied at the public reference room of the Commission at 450 Fifth Street,
N.W., Washington, D.C. 20549 and at the Commission's Regional Offices in New
York, Seven World Trade Center, 13th Floor, New York, New York 10048, and in
Chicago, Citicorp Center, 500 West Madison Street, Suite 1400, Chicago,
Illinois 60661, and copies of such material can be obtained by mail from the
Public Reference Section of the Commission at 450 Fifth Street, N.W.,
Washington, D.C. 20549, at prescribed rates. Such information may also be
accessed electronically by means of the Commission's home page on the Internet
(http://www.sec.gov). In addition, the Common Stock of both M&I and Security
is included for quotation on the Nasdaq National Market, and such reports,
proxy statements and other information concerning M&I and Security is
available for inspection and copying at the offices of the National
Association of Securities Dealers, Inc., 1735 K Street, N.W., Washington, D.C.
20006.
 
  M&I has filed a Registration Statement with the Commission on Form S-4
(together with any amendments thereto, the "Registration Statement") under the
Securities Act of 1933, as amended (the "Securities Act"), with respect to the
shares of M&I Common Stock to be issued in connection with the Merger. As
permitted by the rules and regulations of the Commission, this Proxy
Statement-Prospectus omits certain information, exhibits and undertakings
contained in the Registration Statement. For further information pertaining to
the securities offered by this Proxy Statement-Prospectus, reference is made
to the Registration Statement, including the exhibits filed as a part of it.
Statements contained in this Proxy Statement-Prospectus or in any document
incorporated by reference in it as to the contents of any contract or other
document are not necessarily complete and, in each instance where such
contract or document is an exhibit to the Registration Statement or an
incorporated document, reference is made to the copy of such contract or
document filed as an exhibit to the Registration Statement or such
incorporated document, each such statement being qualified in all respects by
such reference.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
  The following documents filed by M&I (File No. 0-1220) with the Commission
pursuant to the Exchange Act are hereby incorporated by reference into this
Proxy Statement-Prospectus:
 
  (1) M&I's Annual Report on Form 10-K for the year ended December 31, 1996.
 
  (2) M&I's Quarterly Report on Form 10-Q for the quarter ended March 31,
      1997.
 
                                       i
<PAGE>
 
  (3) M&I's Current Report on Form 8-K dated March 14, 1997.
 
  (4) The description of the M&I Common Stock contained in M&I's Registration
      Statement filed pursuant to Section 12(g) of the Exchange Act, any
      amendment or report filed for the purpose of updating such description,
      and as amended by the description of the M&I Common Stock contained
      herein. See "DESCRIPTION OF M&I CAPITAL STOCK."
 
  (5) M&I's Amendment No. 1 to Annual Report on Form 10-K/A dated June 3,
      1997, for the year ended December 31, 1996.
 
  The following documents filed by Security (File No. 0-2453) with the
Commission pursuant to the Exchange Act are hereby incorporated by reference
into this Proxy Statement-Prospectus:
 
  (1) Security's Annual Report on Form 10-K for the year ended June 30, 1996.
 
  (2) Security's Quarterly Reports on Form 10-Q for the quarters ended
      September 30, December 31, 1996 and March 31, 1997.
 
  (3) Security's Current Report on Form 8-K dated March 14, 1997.
 
  All documents filed by M&I and Security pursuant to Sections 13(a), 13(c),
14 and 15(d) of the Exchange Act subsequent to the date of this Proxy
Statement-Prospectus and prior to the date of the Special Meeting shall be
deemed to be incorporated by reference into this Proxy Statement-Prospectus
and to be a part hereof from the dates of filing of such documents. Any
statement contained herein, or in a document all or a portion of which is
incorporated or deemed to be incorporated by reference into this Proxy
Statement-Prospectus, shall be deemed to be modified or superseded for
purposes of this 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 therein 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 Proxy Statement-
Prospectus.
 
  THIS PROXY STATEMENT-PROSPECTUS INCORPORATES DOCUMENTS BY REFERENCE WHICH
ARE NOT PRESENTED IN THIS PROXY STATEMENT-PROSPECTUS OR DELIVERED WITH IT.
THESE DOCUMENTS (EXCLUDING EXHIBITS UNLESS SUCH EXHIBITS ARE SPECIFICALLY
INCORPORATED BY REFERENCE INTO THE INFORMATION INCORPORATED IN THIS PROXY
STATEMENT-PROSPECTUS) ARE AVAILABLE WITHOUT CHARGE TO EACH PERSON, INCLUDING
ANY BENEFICIAL OWNER, TO WHOM A PROXY STATEMENT-PROSPECTUS IS DELIVERED, UPON
ORAL OR WRITTEN REQUEST FROM ANY SUCH PERSON. WITH RESPECT TO M&I'S DOCUMENTS,
REQUESTS SHOULD BE DIRECTED TO SECRETARY, MARSHALL & ILSLEY CORPORATION, 770
NORTH WATER STREET, MILWAUKEE, WISCONSIN 53202 (TELEPHONE: (414) 765-7801).
WITH RESPECT TO SECURITY'S DOCUMENTS, REQUESTS SHOULD BE DIRECTED TO
SECRETARY, SECURITY CAPITAL CORPORATION, 184 WEST WISCONSIN AVENUE, MILWAUKEE,
WISCONSIN 53203 (TELEPHONE: (414) 273-8090). IN ORDER TO ENSURE TIMELY
DELIVERY OF THE DOCUMENTS IN ADVANCE OF THE SPECIAL MEETING, ANY SUCH REQUEST
SHOULD BE MADE BY JULY 1, 1997.
 
  YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED OR INCORPORATED BY
REFERENCE IN THIS PROXY STATEMENT-PROSPECTUS TO VOTE ON THE MERGER. NEITHER
M&I NOR SECURITY HAS AUTHORIZED ANYONE TO PROVIDE YOU WITH INFORMATION THAT IS
DIFFERENT FROM WHAT IS CONTAINED IN THIS PROXY STATEMENT-PROSPECTUS. THIS
PROXY STATEMENT-PROSPECTUS IS DATED JUNE   , 1997. YOU SHOULD NOT ASSUME THAT
THE INFORMATION CONTAINED IN THIS PROXY STATEMENT-PROSPECTUS IS ACCURATE AS OF
ANY DATE OTHER THAN SUCH DATE, AND NEITHER THE MAILING OF THIS PROXY
STATEMENT-PROSPECTUS TO SHAREHOLDERS NOR THE ISSUANCE OF THE M&I COMMON STOCK
IN THE MERGER SHALL CREATE ANY IMPLICATION TO THE CONTRARY.
 
  ALL INFORMATION CONTAINED IN THIS PROXY STATEMENT-PROSPECTUS RELATING TO M&I
HAS BEEN SUPPLIED BY M&I, AND ALL INFORMATION RELATING TO SECURITY HAS BEEN
SUPPLIED BY SECURITY.
 
                                      ii
<PAGE>
 
                          FORWARD-LOOKING STATEMENTS
 
 Cautionary Statement for Purposes of the Private Securities Litigation Reform
                                 Act of 1995.
 
  This Proxy Statement-Prospectus (including information incorporated by
reference herein), information included in, or incorporated by reference from,
future filings by M&I or Security with the Commission, and information
contained in written material, press releases and oral statements issued by or
on behalf of M&I or Security contain, or may contain, certain "forward-looking
statements" including statements concerning plans, objectives and future
events or performance, and other statements which are other than statements of
historical fact. Forward-looking statements also include information
concerning possible or assumed future results of operations of M&I and
Security set forth under "THE MERGER--Reasons for the Merger; Security Board
Recommendation" and "Opinion of Financial Advisor to Security" and those
preceded by, followed by or that include the words "believes," "expects,"
"anticipates" or similar expressions. For those statements, M&I and Security
claim the protection of the safe harbor provisions for forward-looking
statements contained in the Private Securities Litigation Reform Act of 1995.
It should be understood that the following important factors, in addition to
those discussed elsewhere in this document and in the documents incorporated
by reference, could affect the future results of M&I and Security, and could
cause those results to differ materially from those expressed in such forward-
looking statements. Factors that may cause actual results to differ materially
from those contemplated by such forward-looking statements include, but are
not limited to, the following: (i) failure to fully realize or to realize
within the expected time frame expected cost savings from the Merger; (ii)
lower than expected income or revenues following the Merger, or higher than
expected operating costs; (iii) a significant increase in competitive pressure
in the banking and financial services industry; (iv) business disruption
related to the Merger (both before and after completion); (v) greater than
expected costs or difficulties related to the integration of the management of
M&I and Security; (vi) litigation costs and delays caused by litigation; (vii)
higher than anticipated costs in completing the Merger; (viii) unanticipated
regulatory delays or constraints or changes in the proposed transaction
required by regulatory authorities; (ix) reduction in interest margins due to
changes in the interest rate environment; (x) poorer than expected general
economic conditions, including acquisition and growth opportunities, either
nationally or in the states in which the combined company will be doing
business; (xi) legislation or regulatory changes which adversely affect the
businesses in which the combined company would be engaged; (xii) price or
other market factors which may adversely impact M&I's share repurchase
program; and (xiii) other unanticipated occurrences which may delay the
consummation of the Merger, increase the costs related to the Merger or
decrease the expected financial benefits of the Merger.
 
                                      iii
<PAGE>
 
                               TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
AVAILABLE INFORMATION.....................................................   i
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE...........................   i
FORWARD-LOOKING STATEMENTS................................................   i
SUMMARY...................................................................   1
  The Companies...........................................................   1
  The Special Meeting.....................................................   1
  The Merger..............................................................   2
  Reasons for the Merger; Security Board Recommendation...................   4
  Opinion of Financial Advisor............................................   4
  Conditions; Termination; Amendment......................................   4
  Regulatory Approvals....................................................   5
  Accounting Treatment....................................................   5
  Certain Federal Income Tax Consequences of the Merger...................   5
  Interests of Certain Persons in the Merger..............................   6
  Termination Fee.........................................................   6
  No Appraisal or Dissenters' Rights......................................   6
  Comparative Stock Prices................................................   7
  Comparative Unaudited Per Share Data....................................   7
  Selected Historical and Pro Forma Financial Data........................   9
  Illustrative Calculations of Stock Consideration, Cash Consideration,
   Mixed Consideration and Stock Amount...................................  13
THE SPECIAL MEETING.......................................................  14
  General.................................................................  14
  Proposals to be Considered..............................................  14
  Record Dates and Voting Rights..........................................  14
  Voting; Revocation of Proxies...........................................  14
  Solicitation of Proxies.................................................  15
THE MERGER................................................................  16
  General.................................................................  16
  Background of the Merger................................................  16
  Reasons for the Merger; Security Board Recommendation...................  18
  Opinion of Financial Advisor to Security................................  20
  Merger Consideration....................................................  27
  Election Procedures.....................................................  29
  Allocation..............................................................  30
  Effective Time..........................................................  31
  Conversion of Shares; Procedures for Exchange of Certificates;
   Dividends..............................................................  31
  Representations and Warranties..........................................  32
  Conditions to the Merger................................................  33
  Termination; Amendment and Waiver.......................................  34
  Termination Fee.........................................................  35
  Conduct of Business Pending Merger......................................  36
  No Solicitation of Transactions.........................................  37
  Data Processing Conversions.............................................  38
  Management and Operations After the Merger..............................  38
  Interests of Certain Persons in the Merger..............................  38
  Effect on Employee Benefits and Stock Options...........................  41
  Accounting Treatment....................................................  43
  Certain Federal Income Tax Consequences of the Merger...................  43
  Resale of M&I Common Stock by Affiliates................................  45
  No Appraisal or Dissenters' Rights......................................  45
</TABLE>
 
                                       iv
<PAGE>
 
<TABLE>
<CAPTION>
                                                                          PAGE
                                                                          ----
<S>                                                                       <C>
CERTAIN RELATED TRANSACTIONS.............................................  46
  Data Processing Services Agreement.....................................  46
  Trust Services.........................................................  46
CERTAIN REGULATORY CONSIDERATIONS........................................  46
  Federal Reserve Board Approval.........................................  46
  Department of Financial Institutions Approval..........................  47
UNAUDITED PRO FORMA CONDENSED FINANCIAL INFORMATION......................  48
DESCRIPTION OF M&I CAPITAL STOCK.........................................  54
  In General.............................................................  54
  M&I Common Stock.......................................................  54
  M&I Preferred Stock....................................................  54
  M&I Series A Preferred Stock...........................................  55
  Certain Provisions of the Wisconsin Business Corporation Law...........  55
COMPARISON OF SHAREHOLDER RIGHTS.........................................  56
  Authorized Capital Stock...............................................  56
  Required Vote..........................................................  57
  Size of Board of Directors.............................................  57
  Removal of Directors for "Cause" ......................................  57
  Advance Notice of Proposals to be Brought at the Annual Meeting........  58
  Advance Notice of Nominations of Directors.............................  58
  Certain Business Combinations..........................................  58
CERTAIN INFORMATION CONCERNING M&I AND SECURITY..........................  59
EXPERTS..................................................................  59
LEGAL MATTERS............................................................  60
SHAREHOLDER PROPOSALS....................................................  60
APPENDIX A Agreement and Plan of Merger.................................. A-1
APPENDIX B Illustrative Calculation of Stock Consideration, Cash Consid-
            eration, Mixed Consideration and Stock Amount................ B-1
APPENDIX C Fairness Opinion of Robert W. Baird & Co. Incorporated........ C-1
</TABLE>
 
 
                                       v
<PAGE>
 
                                    SUMMARY
 
  The following is a summary of certain information contained elsewhere in the
Proxy Statement-Prospectus. This Summary is not intended to be complete and is
qualified in its entirety by reference to the more detailed information
contained elsewhere in this Proxy Statement-Prospectus, the attached appendices
and the documents incorporated by reference herein. Shareholders are urged to
read carefully this Proxy Statement-Prospectus and the attached appendices in
their entirety.
 
THE COMPANIES
 
  M&I. Marshall & Ilsley Corporation ("M&I" or "the Company"), is a registered
bank holding company under the Bank Holding Company Act of 1956, as amended
(the "BHCA") headquartered in Milwaukee, Wisconsin. M&I's principal assets are
the stock of its bank and nonbank subsidiaries and the assets of its Data
Services Division ("M&I Data Services"). M&I's bank and savings association
subsidiaries provide a full range of banking services to individuals,
businesses and governments throughout Wisconsin and the Phoenix, Arizona
metropolitan area. M&I's nonbank subsidiaries operate a variety of bank-related
businesses, including investment management services, insurance services, trust
services, equipment lease financing, commercial and residential mortgage
banking, venture capital, brokerage services and financial advisory services.
M&I Data Services is a major supplier of financial and data processing services
and software to banking, financial and related organizations. As of March 31,
1997, M&I had consolidated total assets of approximately $14.9 billion,
consolidated total deposits of approximately $10.8 billion and consolidated
shareholders' equity of approximately $1.3 billion. M&I's principal executive
offices are located at 770 North Water Street, Milwaukee, Wisconsin 53202, and
its telephone number is (414) 765-7801.
 
  Security. Security is a Wisconsin corporation incorporated in 1993 and a
registered bank holding company under the BHCA. Security's principal assets are
the stock of its subsidiaries. Security presently owns 100% of the capital
stock of Security Bank S.S.B. ("Security Bank") which has a total of 42
branches and 10 lending offices in Wisconsin. Security Bank also has other
wholly-owned subsidiaries engaged in businesses which are closely related to
banking, including the businesses of mortgage lending, leasing services,
brokerage services and insurance agency services. Security Bank provides
financial and managerial assistance and services to its subsidiaries. At March
31, 1997, Security had consolidated total assets of approximately $3.6 billion,
consolidated total deposits of approximately $2.3 billion and consolidated
shareholders' equity of approximately $578 million. Security's principal
executive offices are located at 184 West Wisconsin Avenue, Milwaukee,
Wisconsin 53203, and its telephone number is (414) 273-8090.
 
THE SPECIAL MEETING
 
  The Special Meeting will be held on Wednesday, July 9, 1997, at 10:00 a.m.,
Milwaukee time, at The Grand Milwaukee Hotel, Grand Ballroom East, 4747 South
Howell Avenue, Milwaukee, Wisconsin. At the Special Meeting, Security
shareholders will be asked to consider and vote upon a proposal to approve the
Merger Agreement, the Merger and the transactions contemplated thereby. Holders
of Security Common Stock at the close of business on June 4, 1997 (the "Record
Date") will be entitled to notice of and to vote at the Special Meeting. Each
share of Security Common Stock is entitled to one vote. As of the Record Date,
there were 9,095,632 outstanding shares of Security Common Stock entitled to
vote at the Special Meeting, of which 1,833,913 shares or approximately 18.3%
were beneficially owned by Security directors, executive officers and their
affiliates. The affirmative vote of a majority of the holders of the
outstanding shares of Security Common Stock as of the Record Date is required
to approve the Merger Agreement. See "THE SPECIAL MEETING."
 
  An abstention with respect to Security proposals will have the effect of a
vote cast against the proposal. Brokers who hold shares of Security Common
Stock as nominees will not have discretionary authority to vote such shares on
the proposal in the absence of instructions from the beneficial owners thereof.
Any votes which are not cast by the nominee-broker will have the effect of
votes cast against such proposal.
 
                                       1
<PAGE>
 
 
  A holder of Security Common Stock may revoke a proxy at any time before it is
voted by the filing of an instrument revoking the proxy or of a duly executed
proxy bearing a later date with the Corporate Secretary of Security prior to or
at the Special Meeting, or by attending the Special Meeting and voting in
person. Attendance at the Special Meeting will not by itself constitute
revocation of a proxy.
 
  SECURITY'S BOARD OF DIRECTORS HAS DETERMINED THAT THE TERMS OF THE MERGER
AGREEMENT AND THE TRANSACTIONS CONTEMPLATED THEREBY ARE IN THE BEST INTERESTS
OF SECURITY AND ITS SHAREHOLDERS. ACCORDINGLY, SECURITY'S BOARD OF DIRECTORS
UNANIMOUSLY RECOMMENDS THAT SECURITY SHAREHOLDERS VOTE FOR APPROVAL AND
ADOPTION OF THE MERGER AGREEMENT.
 
THE MERGER
 
  General. M&I and Security have entered into the Merger Agreement which
provides, after satisfaction or waiver of all conditions described therein, for
the Merger of Security with and into M&I, with M&I being the surviving
corporation. The Merger will become effective (the "Effective Time") upon the
filing of Articles of Merger with the Wisconsin Department of Financial
Institutions ("DFI"), which is expected to occur as promptly as practicable
following shareholder and regulatory approvals and the satisfaction or waiver
of other conditions contained in the Merger Agreement and completion of the
conversion of Security's bank offices to M&I's data processing systems,
including any and all testing relating to such conversion. See "THE MERGER--
Data Processing Conversion."
 
  Merger Consideration. The Merger Agreement provides that, at the Effective
Time of the Merger and subject to the election and allocation procedures
provided for therein, each share of Security Common Stock outstanding at the
Effective Time will be converted into one of the following (the "Merger
Consideration"): (i) approximately $41.40 in cash and approximately 1.3561
shares of M&I Common Stock (the "Mixed Consideration"), (ii) subject to the
allocation procedures applicable to oversubscriptions for elections to receive
M&I Common Stock described below, a number of shares of M&I Common Stock
("Stock Consideration"), or (iii) subject to the allocation procedures
applicable to oversubscriptions for elections to receive cash, an amount in
cash without interest ("Cash Consideration"). The actual Stock Consideration
and Cash Consideration will be determined based on a formula, set forth in the
Merger Agreement, which takes into consideration (i) the average of the average
final bid and asked quotations for M&I Common Stock (the "Valuation Period
Market Value") as reported on the Nasdaq National Market during the ten (10)
consecutive trading-day period ending on the fifth calendar day immediately
prior to the Effective Time (the "Valuation Period"); and (ii) the total number
of shares of Security Common Stock outstanding as of the end of the Valuation
Period (the "Valuation Period Share Number"). A table is provided on page 13
and in Appendix B of this Proxy Statement-Prospectus which sets forth examples
of the amount of cash and M&I Common Stock to be issued in the Merger and the
actual number of shares of M&I Common Stock to be issued in the Merger per
share of Security Common Stock based upon various assumed Valuation Period
Market Values and an assumed Valuation Period Share Number. See "THE MERGER--
Merger Consideration."
 
  Based on the closing price on the Nasdaq National Market of M&I Common Stock
on March 14, 1997 of $37.3125 per share, a holder of Security Common Stock
electing to receiving a combination of cash and stock would receive $41.40 in
cash and 1.3561 shares of M&I Common Stock per share of Security Common Stock
and, subject to the election and allocation procedures provided for in the
Merger Agreement, a holder of Security Common Stock receiving all stock would
receive approximately 2.4657 shares of M&I Common Stock per share of Security
Common Stock with a Valuation Period Market Value equal to $92 per share of
Security Common Stock, and a holder of Security Common Stock receiving all cash
would receive $92 per share of Security Common Stock. THE VALUE PER SHARE OF
CASH OR SECURITY COMMON STOCK RECEIVED IN THE MERGER WILL VARY WITH THE MARKET
VALUE OF M&I COMMON STOCK.
 
 
                                       2
<PAGE>
 
  No fractional shares of M&I Common Stock will be issued to any holder of
Security Common Stock upon surrender of its certificates representing Security
Common Stock in connection with the Merger. In lieu thereof, holders of
Security Common Stock will be entitled to a cash payment for fractional shares.
 
  Under the Merger Agreement, the aggregate number of shares of M&I Common
Stock to be issued in the Merger (the "Stock Amount") is equal to 12,327,390,
and the aggregate cash payable by M&I to holders of Security Common Stock
pursuant to the Merger is equal to $376,335,605, regardless of the Valuation
Period Market Value. The total consideration to be received by Security
shareholders could vary slightly, therefore, if the number of shares of
Security Common Stock outstanding at the end of the Valuation Period and at the
Effective Time differs from 9,090,232. This is not expected to happen, however,
since under the terms of the Merger Agreement (i) Security is prohibited from
issuing any shares of its Common Stock except pursuant to existing stock
options, and (ii) Security has agreed, to the extent permitted by law, to
repurchase shares of its Common Stock equal to the number of shares issued
pursuant to stock options.
 
  THE CONSIDERATION VALUE TO EACH INDIVIDUAL SHAREHOLDER AND RELATIVE VALUE OF
THE M&I COMMON STOCK AND CASH RECEIVED WILL VARY WITH THE PRICE OF THE M&I
COMMON STOCK FINALLY DETERMINED BASED ON THE VALUATION PERIOD MARKET VALUE. THE
MARKET PRICE OF M&I COMMON STOCK MAY FLUCTUATE AND, ON THE DATE OF RECEIPT OF
M&I COMMON STOCK BY HOLDERS OF SECURITY COMMON STOCK, MAY BE MORE OR LESS THAN
THE VALUATION PERIOD MARKET VALUE.
 
  Election Procedures. At least thirty (30) days prior to the Effective Time
(the "Mailing Date"), a bank or trust company that will be designated by M&I
and Security (the "Exchange Agent") will send to each holder of Security Common
Stock who is a shareholder of record as of five (5) business days prior to the
Mailing Date an election form to be used by each such holder of Security Common
Stock to elect to receive in the Merger either: (i) a combination of cash and
whole shares of M&I Common Stock plus cash in lieu of any fractional shares;
(ii) all whole shares of M&I Common Stock plus cash in lieu of any fractional
shares; (iii) all cash; or (iv) to make no election in respect of such holder's
shares of Security Common Stock.
 
  All elections by holders of Security Common Stock to receive a combination of
cash and M&I Common Stock will be given priority and will receive approximately
$41.40 in cash and approximately 1.3561 shares of M&I Common Stock in exchange
for each share of Security Common Stock. However, because the number of shares
of M&I Common Stock to be issued and the amount of cash to be paid in the
Merger will be fixed, under the election and allocation procedures set forth in
the Merger Agreement, the extent to which elections for all M&I Common Stock or
all cash will be accommodated will depend upon the respective number of holders
of Security Common Stock who elect to receive a combination of cash and M&I
Common Stock or who make no election.
 
  An election by a holder of Security Common Stock to receive only shares of
M&I Common Stock may instead result in receipt of cash for some of such
holder's shares of Security Common Stock, or an election by a holder of
Security Common Stock to receive only cash may result in receipt of shares of
M&I Common Stock (plus cash in lieu of any fractional share) for some of such
holder's shares of Security Common Stock.
 
  Holders of Security Common Stock who do not timely submit properly completed
election forms by 5:00 p.m., New York City time, on the twenty-fifth (25th) day
following, but not including, the Mailing Date (the "Election Deadline") will
be deemed to have made no election as to whether they receive a combination of
M&I Common Stock and cash in the Merger or M&I Common Stock or cash. Holders of
Security Common Stock who make no election will be given either all cash, all
whole shares of M&I Common Stock plus cash in lieu of any fractional shares, or
a combination of cash and whole shares of M&I Common Stock plus cash in lieu of
any fractional shares, depending upon the respective number of holders of
Security Common Stock who elect to receive cash or M&I Common Stock or who make
no election. See "THE MERGER--Election Procedures."
 
 
                                       3
<PAGE>
 
  BECAUSE THE AGGREGATE NUMBER OF SHARES OF M&I COMMON STOCK AND THE AGGREGATE
AMOUNT OF CASH TO BE EXCHANGED IN THE MERGER WILL BE FIXED (SUBJECT TO THE
ELECTION AND ALLOCATION PROCEDURES DESCRIBED HEREIN), NO ASSURANCE CAN BE GIVEN
THAT AN ELECTION BY ANY GIVEN HOLDER OF SECURITY COMMON STOCK TO RECEIVE ONLY
CASH OR ONLY STOCK WILL BE HONORED WITH RESPECT TO ANY SHARES OF SECURITY
COMMON STOCK HELD BY SUCH HOLDER. THUS, HOLDERS WHO MAKE SUCH ELECTIONS MAY NOT
RECEIVE THEIR REQUESTED FORM OF CONSIDERATION. SEE "THE MERGER--ELECTION
PROCEDURES." BECAUSE THE TAX CONSEQUENCES OF RECEIVING CASH OR M&I COMMON STOCK
WILL DIFFER, HOLDERS OF SECURITY COMMON STOCK ARE URGED TO READ CAREFULLY THE
INFORMATION SET FORTH UNDER THE CAPTION "THE MERGER--CERTAIN FEDERAL INCOME TAX
CONSEQUENCES OF THE MERGER."
 
REASONS FOR THE MERGER; SECURITY BOARD RECOMMENDATION
 
  M&I. The M&I Board of Directors has determined that the Merger is desirable
since it enhances M&I's market position in Wisconsin, may result in the
opportunity for significant cost savings, and is attractive from a financial
point of view. See "THE MERGER--Reasons for the Merger; Security Board
Recommendation."
 
  Security. The Security Board of Directors believes that the terms of the
Merger Agreement are in the best interests of holders of Security Common Stock.
In reaching its opinion, the Security Board of Directors considered a number of
factors, including, among other factors, the advantages of combining with
another Wisconsin-based bank, the strategic fit of M&I and Security, the
competitive environment facing Security, the opinion of Robert W. Baird & Co.
Incorporated ("Baird"), and the financial outlook and condition of M&I. See
"THE MERGER--Reasons for the Merger; Security Board Recommendation."
 
  See "THE MERGER--Interests of Certain Persons in the Merger" for information
regarding interests of certain officers and directors of Security in the
Merger.
 
OPINION OF FINANCIAL ADVISOR TO SECURITY
 
  Baird has delivered to the Board of Directors of Security its written
opinion, dated March 14, 1997, that, as of such date, the Merger Consideration
is fair, from a financial point of view, to the holders of Security Common
Stock (other than M&I and its affiliates). The full text of the opinion of
Baird, which sets forth the assumptions made, procedures followed, matters
considered and limitations on the review undertaken, is attached as Appendix C
to this Proxy Statement-Prospectus. HOLDERS OF SECURITY COMMON STOCK ARE URGED
TO READ SUCH OPINION CAREFULLY AND IN ITS ENTIRETY. See "THE MERGER--Opinion of
Financial Advisor to Security."
 
CONDITIONS; TERMINATION; AMENDMENT
 
  Consummation of the Merger is subject to various conditions, including (a)
approval of the Merger Agreement by Security shareholders, (b) receipt of
regulatory approvals absent any conditions that are materially burdensome to
M&I, (c) the absence of any material adverse change in the financial condition,
results of operations or business of M&I or Security, and (d) receipt of
opinions of counsel with respect to certain U.S. federal income tax
consequences of the Merger. See "THE MERGER--Conditions to the Merger." Under
the terms of the Merger Agreement, the Merger cannot be consummated until the
earlier of (i) the completion of the data processing conversion of Security's
branch offices, or (ii) October 1, 1997. The parties currently anticipate the
Merger will be completed (subject to fulfilling various conditions) on or about
October 1, 1997. See "THE MERGER--Conditions to the Merger" and "THE MERGER--
Data Processing Conversion."
 
  In addition, the Merger Agreement may be terminated notwithstanding
shareholder approval, if certain specified events occur. For example, either
M&I or Security may terminate the Merger Agreement if the Merger
 
                                       4
<PAGE>
 
has not been consummated by December 31, 1997, unless the Merger has not been
consummated as a result of certain governmental proceedings or litigation
related to the Merger, in which case either M&I or Security may terminate the
Merger Agreement if the Merger has not been consummated by April 30, 1998. In
addition, Security may terminate the Merger Agreement on the day preceding the
Effective Time if (a) the average of the daily closing price of a share of M&I
Common Stock as reported on the Nasdaq National Market during the period of ten
(10) trading days ending at the close of the third trading day immediately
preceding the Effective Time (the "M&I Average Price") is less than $30.875,
and (b) the M&I Average Price has declined by more than 15% relative to the
decline in the market prices of a selected group of bank stocks during the same
period. In this event, M&I has the right to increase the amount of the Stock
Consideration such that the conditions in (a) or (b) are deemed not to exist.
See "THE MERGER--Termination; Amendment and Waiver."
 
  The conditions to the Merger may be waived by the party entitled to assert
the condition. If any material condition to the Merger is waived, Security and
its Board of Directors will consult with legal counsel as to the necessity of
amending this Proxy Statement-Prospectus and resoliciting proxies for the
Special Meeting.
 
  The Merger Agreement may be amended by the mutual consent of M&I and Security
at any time prior to the Effective Time provided that, after approval of the
Merger Agreement by shareholders of Security, no amendment may be made which
would reduce the amount or change the type of consideration into which each
share of Security Common Stock would be converted. See "THE MERGER--
Termination; Amendment and Waiver."
 
REGULATORY APPROVALS
 
  The Merger is subject to prior approval by the Board of Governors of the
Federal Reserve System (the "Federal Reserve Board") and the DFI. M&I submitted
applications seeking approval of the Merger with the Federal Reserve Board and
DFI on April 1, 1997. Certain aspects of the Merger will require notification
to, or approvals from, certain other federal and state regulatory authorities.
Based on the treatment of prior mergers and acquisitions involving other
parties, M&I anticipates that certain divestitures may be required by the
Federal Reserve Board or the Department of Justice as a condition to regulatory
approval of the Merger, and M&I has filed applications with the Federal Reserve
Board proposing divestiture of certain bank branches.
 
  At the present time, M&I management has preliminarily identified seven
branches in the State of Wisconsin with total deposits of approximately $125
million as candidates for divestiture. There can be no assurance, however, as
to the number of divestitures that will ultimately be required in connection
with the regulatory approval of the Merger. The impact of these divestitures
has not been quantified; however, it is anticipated that the impact will not be
material to the results of operations or financial condition of the combined
entity.
 
  The Federal Reserve Board has in the past generally required that any
divestitures be made prior to the consummation of the merger with respect to
which approval is sought. There can be no assurances that the regulatory
authorities will approve the Merger, or if approved, as to the date of such
approvals. There can also be no assurances that any such approvals will not
contain a condition or requirement which causes such approvals to fail to
satisfy the conditions to the consummation of the Merger. There can be no
assurance that the Department of Justice will not challenge the Merger, or as
to the result of any such challenge, if made. See "CERTAIN REGULATORY
CONSIDERATIONS."
 
ACCOUNTING TREATMENT
 
  The Merger will be accounted for as a purchase. See "THE MERGER--Accounting
Treatment."
 
CERTAIN FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER
 
  The Merger has been structured with the intent that it be treated as a
reorganization within the meaning of Section 368(a) of the Internal Revenue
Code of 1986, as amended (the "Code"). Consummation of the Merger
 
                                       5
<PAGE>
 
is conditioned on M&I receiving an opinion from Godfrey & Kahn, S.C. and
Security receiving an opinion from Skadden, Arps, Slate, Meagher & Flom LLP,
each dated as of the Effective Time, on the basis of facts, representations and
assumptions set forth or referred to in such opinions, which are consistent
with the state of facts existing at the Effective Time that the Merger will be
treated for U.S. federal income tax purposes as a reorganization within the
meaning of Section 368(a) of the Code. In rendering their opinions, counsel
will require and rely upon, and assume the accuracy of, representations of M&I,
Security, certain shareholders of Security and others. See "THE MERGER--Certain
Federal Income Tax Consequences of the Merger." Security shareholders should
consult their tax advisors as to the tax consequences of the Merger under
federal, state, local or other applicable laws.
 
INTERESTS OF CERTAIN PERSONS IN THE MERGER
 
  Certain executive officers and directors of Security may receive economic
benefits as a result of the Merger under various benefit plans and employment
arrangements.
 
  The Merger Agreement provides for, among other things, (i) indemnification of
Security directors, officers and employees and the maintenance of directors'
and officers' liability insurance by M&I for six years following the Merger,
provided that M&I will not be required to expend more than 200% of the current
amount expended by Security, (ii) the payment to Messrs. Argue, Gordon, Kamin,
Schaefer, Schoendorf, Schuett, Jr. and Schuett, Sr., within 30 days following
the Effective Time, of change in control severance payments to which each such
executive is entitled of approximately $765,000, $525,000, $665,000, $900,000,
$415,000, $500,000 and $1,100,000, respectively, even if employment is not
terminated, and (iii) the surrender at the Effective Time of outstanding non-
qualified stock options of Security for a cash payment equal to the excess of
the Average Per Share Consideration over the exercise price of such option,
multiplied by the number of shares covered by such options. Messrs. Argue,
Gordon, Kamin, Schaefer, Schoendorf, Schuett, Jr. and Schuett, Sr. hold
approximately 4,000, 17,952, 0, 194,000, 146,000, 28,000, and 240,000 non-
qualified stock options, respectively. All other executive officers and
directors of Security as a group hold approximately 136,000 non-qualified
options. The Merger will constitute a "change of control" under the employment
agreements of the seven individuals referenced in clause (ii), resulting in the
change in control severance payments to such individuals described above.
 
  The Security Board of Directors was aware of these interests and considered
them, among other matters, in unanimously approving the Merger Agreement and
the transactions contemplated thereby. See "THE MERGER--Interests of Certain
Persons in the Merger."
 
TERMINATION FEE
 
  Under the Merger Agreement, upon the occurrence of specified events, Security
must pay M&I a fee of $30 million (the "Termination Fee"). Generally, the
Termination Fee will be payable if the Merger Agreement is terminated, a
trigger event occurs (e.g., approval of an alternative transaction by Security)
and Security consummates a business combination with an entity other than M&I
within 18 months of the termination. As of the date of this Proxy Statement--
Prospectus, to the best of M&I's and Security's knowledge, none of the events
which could lead to the fee being payable has occurred. In addition, if (i) the
Merger Agreement is terminated (regardless of whether such termination is by
M&I and Security) and (ii) a trigger event has occurred, Security is required
to pay to M&I its reasonable out-of-pocket expenses related to the transactions
contemplated in the Merger Agreement, not to exceed $2,500,000. See "THE
MERGER--Termination Fee."
 
NO APPRAISAL OR DISSENTERS' RIGHTS
 
  Under the Wisconsin Business Corporation Law (the "WBCL"), subject to certain
exceptions inapplicable to the Merger, holders of shares of a Wisconsin
corporation quoted on the Nasdaq National Market on the record date fixed to
determine shareholders entitled to notice of a shareholders meeting at which
shareholders are to
 
                                       6
<PAGE>
 
vote on a merger are not entitled to appraisal or dissenters' rights. Since the
Security Common Stock was quoted on the Nasdaq National Market as of the Record
Date, holders of Security Common Stock have no appraisal or dissenters' rights
with respect to the Merger. See "THE MERGER--No Appraisal or Dissenters'
Rights."
 
COMPARATIVE STOCK PRICES
 
  M&I Common Stock and Security Common Stock are quoted on the Nasdaq National
Market, under the symbols MRIS and SECP, respectively. The following table sets
forth the closing sale price per share of M&I Common Stock and Security Common
Stock on March 14, 1997, the last trading day preceding the public announcement
of the execution of the Merger Agreement, and on June 3, 1997.
 
<TABLE>
<CAPTION>
                                                                       SECURITY
                                                       HISTORICAL     EQUIVALENT
                                                    -----------------    PER
                                                      M&I    SECURITY  SHARE(1)
                                                    -------- -------- ----------
   <S>                                              <C>      <C>      <C>
   March 14, 1997.................................. $37.3125  $84.75    $92.00
   June 3, 1997.................................... $39.9375  $92.00    $95.56
</TABLE>
- --------
(1) Represents the closing price of M&I Common Stock on the date presented
    multiplied by 1.3561, plus $41.40.
 
  Shareholders are urged to obtain current market quotations for shares of M&I
Common Stock and Security Common Stock. No prediction or assurance can be made
or given as to the market price of M&I Common Stock at the Effective Time of
the Merger or afterward. A table giving examples of the results of various
possible elections by a holder of Security common stock based on different
average prices of M&I common stock appears at page 13 and is attached as
Appendix B to the Proxy Statement-Prospectus.
 
 
COMPARATIVE UNAUDITED PER SHARE DATA
 
  The following table sets forth (i) selected comparative per share data for
each of M&I and Security on a historical basis and (ii) selected unaudited pro
forma combined and pro forma equivalent per share data reflecting the
consummation of the Merger using the purchase method of accounting. The
unaudited pro forma comparative per share data assumes the Merger had been
consummated at the beginning of the period presented. The Security pro forma
equivalent amounts are presented with respect to each set of pro forma
information, and have been calculated by multiplying the corresponding pro
forma combined amounts per share by the implied exchange ratio which is based
on the outstanding Common Stock of Security, as adjusted, as of March 31, 1997
and December 31, 1996.
 
  The unaudited pro forma comparative per share data reflects the Merger based
upon preliminary purchase accounting adjustments. Actual adjustments, which may
include adjustments to additional assets, liabilities and other items, will be
made on the basis of appraisals and evaluations as of the Effective Time and,
therefore, are likely to differ from those reflected in the unaudited pro forma
comparative per share data.
 
  M&I and Security expect that the combined company will achieve substantial
benefits from the Merger including operating cost savings. However, the
unaudited pro forma comparative per share data does not reflect any direct
costs or potential savings which are expected to result from the consolidation
of operations of M&I and Security, and therefore, does not purport to be
indicative of the results of future operations.
 
  The comparative per share data presented herein is based on and derived from,
and should be read in conjunction with, the historical consolidated financial
statements and the related notes thereto of M&I and Security included in the
documents described under "INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE" and
the unaudited pro forma condensed financial statements and accompanying
discussion and notes set forth under "UNAUDITED PRO FORMA CONDENSED FINANCIAL
INFORMATION." Interim results of M&I for the three months ended March 31, 1997
and of Security for the nine months ended March 31, 1997 are not necessarily
indicative of results expected for the entire year, nor are pro forma amounts
necessarily indicative of results of operations or the combined financial
position that would have resulted had the Merger
 
                                       7
<PAGE>
 
been consummated at the beginning of the period indicated. All adjustments
consisting of only normal recurring adjustments necessary for a fair statement
of results of interim periods have been included.
 
<TABLE>
<CAPTION>
                                          HISTORICAL
                                        ---------------
                                                                    SECURITY
                                                        PRO FORMA   PRO FORMA
                                         M&I   SECURITY COMBINED  EQUIVALENT(3)
                                        ------ -------- --------- -------------
<S>                                     <C>    <C>      <C>       <C>
NET INCOME(1)(2)
  Three months ended March 31, 1997.... $ 0.56  $ 1.45   $ 0.55      $ 0.75
  Nine months ended March 31, 1997.....           3.24
  Twelve months ended December 31,
   1996................................   2.02    3.60     1.82        2.47
  Twelve months ended June 30, 1996....           3.40
CASH DIVIDENDS(4)
  Three months ended March 31, 1997.... $0.185  $0.300   $0.185      $0.251
  Nine months ended March 31, 1997.....          0.675
  Twelve months ended December 31,
   1996................................  0.720   0.675    0.720       0.976
  Twelve months ended June 30, 1996....          0.450
BOOK VALUE PER COMMON SHARE
  As of March 31, 1997................. $13.29  $63.50   $16.02      $21.72
  As of December 31, 1996..............  13.37   62.42    16.14       21.89
</TABLE>
- --------
(1) Earnings per share is on a fully diluted basis.
(2) Security's fiscal year end is June 30. For purposes of the unaudited pro
    forma financial information, Security's historical results of operations
    including per share information have been restated to conform to M&I's
    fiscal year end which is December 31.
(3) The Security pro forma equivalent represents the Pro Forma Combined amount
    multiplied by the implied exchange ratio which is based on the outstanding
    Common Stock of Security, as adjusted. The exchange ratio used was 1.3561.
(4) Pro Forma combined dividends per share represent historical dividends per
    share paid by M&I.
 
                                       8
<PAGE>
 
SELECTED HISTORICAL AND PRO FORMA FINANCIAL DATA
 
  The following tables set forth (i) selected historical consolidated financial
data for the periods and as of the dates indicated for M&I and for Security and
(ii) unaudited pro forma selected financial data for the periods and as of the
dates indicated, reflecting the consummation of the Merger using the purchase
method of accounting.
 
  The unaudited pro forma selected financial data reflects the Merger based
upon preliminary purchase accounting adjustments. Actual adjustments, which may
include adjustments to additional assets, liabilities and other items, will be
made on the basis of appraisals and evaluations as of the Effective Time and,
therefore, are likely to differ from those reflected in the unaudited pro forma
selected financial data.
 
  The consummation of the Merger is dependent upon obtaining regulatory
approvals, which may necessitate divestitures of certain bank branches. The
ultimate composition of the divestitures has not been finalized, and
accordingly, no adjustment for divestitures has been included in the pro forma
data.
 
  M&I and Security expect that the combined company will achieve substantial
benefits from the Merger including operating cost savings. However, the
unaudited pro forma selected financial data does not reflect any direct costs
or potential savings which are expected to result from the consolidation of
operations of M&I and Security, and therefore does not purport to be indicative
of the results of future operations.
 
  The following information should be read in conjunction with and is qualified
in its entirety by the consolidated financial statements and the related notes
thereto of M&I and Security included in the documents described under
"INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE" and the unaudited pro forma
condensed financial statements and accompanying discussion and notes set forth
under "UNAUDITED PRO FORMA CONDENSED FINANCIAL INFORMATION." Results of M&I for
the three months ended March 31, 1997 and 1996, and results for Security for
the nine months ended March 31, 1997 and 1996, are not necessarily indicative
of results expected for the entire year, nor are pro forma amounts necessarily
indicative of results of operations or the combined financial position that
would have resulted had the Merger been consummated at the beginning of the
period indicated. All adjustments consisting of only normal recurring
adjustments necessary for a fair statement of results of interim periods have
been included.
 
                                       9
<PAGE>
 
                 MARSHALL & ILSLEY CORPORATION AND SUBSIDIARIES
 
                SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                  THREE MONTHS ENDED
                                       MARCH 31,
                                      (UNAUDITED)                        YEARS ENDED DECEMBER 31,
                                ----------------------- -----------------------------------------------------------
                                   1997        1996        1996        1995        1994        1993        1992
                                ----------- ----------- ----------- ----------- ----------- ----------- -----------
<S>                             <C>         <C>         <C>         <C>         <C>         <C>         <C>
SUMMARIZED INCOME STATEMENT
 DATA:
Net Interest Income...........  $   129,642 $   122,637 $   505,719 $   491,477 $   491,227 $   480,279 $   472,551
Provision for Loan Losses.....        4,311       3,577      15,194      16,158      24,907      18,034      23,546
Other Income..................      137,595     112,713     503,320     424,182     361,481     371,926     328,411
Other Expense.................      180,767     159,189     680,704     599,622     584,770     569,587     545,624
Merger Restructuring Expense..          --          --          --          --       75,228         --          --
Provision for Income Taxes....       27,360      26,429     109,711     106,580      73,405      93,190      75,391
                                ----------- ----------- ----------- ----------- ----------- ----------- -----------
Income Before Extraordinary
 Items and Cumulative Effect
 of Changes in Accounting
 Principles...................       54,799      46,155     203,430     193,299      94,398     171,394     156,401
Extraordinary Items, Net of
 Income Taxes.................          --          --          --          --       11,542         --          --
Cumulative Effect of Changes
 in Accounting Principles, Net
 of Income Taxes..............          --          --          --          --          --          --       (9,134)
                                ----------- ----------- ----------- ----------- ----------- ----------- -----------
Net Income....................  $    54,799 $    46,155 $   203,430 $   193,299 $   105,940 $   171,394 $   147,267
                                =========== =========== =========== =========== =========== =========== ===========
PER SHARE DATA:
Primary Net Income............  $      0.57 $      0.47 $      2.07 $      1.96 $      1.07 $      1.67 $      1.46
Fully Diluted Net Income......         0.56        0.46        2.02        1.90        1.04        1.60        1.40
Book Value....................        13.29       13.02       13.37       12.92       11.01       11.35       10.76
Cash Dividends per Common
 Share........................        0.185       0.165       0.720       0.645       0.590       0.540       0.470
WEIGHTED AVERAGE NUMBER OF
 SHARES:
Primary.......................       96,385      98,192      98,482      98,757      99,420     102,672     101,029
Fully Diluted.................       98,288     102,089     101,197     102,955     104,051     108,875     107,412
AVERAGE BALANCE SHEET DATA:
Total Assets..................  $14,607,543 $13,099,794 $13,655,557 $12,725,511 $12,432,461 $12,039,468 $11,525,409
Total Borrowings..............    2,384,443   1,588,274   1,837,379   1,636,406   1,412,104     913,877     813,861
Shareholders' Equity..........    1,278,140   1,265,879   1,280,841   1,177,825   1,097,963   1,121,314   1,010,667
</TABLE>
 
 
                                       10
<PAGE>
 
                 SECURITY CAPITAL CORPORATION AND SUBSIDIARIES
 
                SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                            NINE MONTHS ENDED
                                MARCH 31,
                               (UNAUDITED)                       YEARS ENDED JUNE 30,
                          --------------------- -------------------------------------------------------
                             1997       1996       1996       1995       1994        1993       1992
                          ---------- ---------- ---------- ---------- ----------  ---------- ----------
<S>                       <C>        <C>        <C>        <C>        <C>         <C>        <C>
SUMMARIZED INCOME STATE-
 MENT DATA:
Net Interest Income.....  $   94,735 $   85,179 $  114,958 $  103,575 $   95,127  $   93,800 $   85,218
Provision for Loan Loss-
 es.....................       1,247      4,619      5,625      5,867      5,999       9,808      5,967
Other Income............      17,023     15,529     20,784     19,715     24,430      25,754     19,461
Other Expense...........      65,168     59,743     79,015     77,424     78,665      75,689     67,635
Provision for Income
 Taxes..................      14,967     14,031     18,650     14,908     13,675      15,834     14,985
                          ---------- ---------- ---------- ---------- ----------  ---------- ----------
Income Before Cumulative
 Effect of Changes in
 Accounting Principles..      30,376     22,315     32,452     25,091     21,218      18,223     16,092
Cumulative Effect of
 Changes in Accounting
 Principles, Net of
 Income Taxes...........         --         --         --         --        (889)        --       2,112
                          ---------- ---------- ---------- ---------- ----------  ---------- ----------
Net Income..............  $   30,376 $   22,315 $   32,452 $   25,091 $   20,329  $   18,223 $   18,204
                          ========== ========== ========== ========== ==========  ========== ==========
PER SHARE DATA:
Primary Net Income......  $     3.27 $     2.33 $     3.40 $     2.53 $     1.05*        N/A        N/A
Fully Diluted Net In-
 come...................        3.24       2.32       3.40       2.52       1.04*        N/A        N/A
Book Value..............       63.50      59.83      60.69      57.02      52.76         N/A        N/A
Cash Dividends Per
 Common Share...........       0.675      0.300      0.450        --         --          N/A        N/A
WEIGHTED AVERAGE NUMBER
 OF SHARES:
Primary.................       9,281      9,595      9,532      9,930     11,094         N/A        N/A
Fully Diluted...........       9,366      9,616      9,557      9,965     11,211         N/A        N/A
AVERAGE BALANCE SHEET
 DATA:
Total Assets............  $3,546,336 $3,239,812 $3,267,955 $2,869,725 $2,358,203  $2,225,022 $2,217,626
Total Advances and
 Borrowings.............     642,899    433,979    452,895    367,982     51,407      33,965     46,356
Shareholders' Equity....     565,977    564,082    562,538    551,099    438,646     298,554    280,322
</TABLE>
- --------
   * Earnings per share is calculated from the date of the stock conversion
     (December 30, 1993).
 
 
                                       11
<PAGE>
 
             PRO FORMA SELECTED COMBINED FINANCIAL DATA (UNAUDITED)
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
<TABLE>
<CAPTION>
                                                         FOR THE      FOR THE
                                                          THREE        TWELVE
                                                       MONTHS ENDED MONTHS ENDED
                                                        MARCH 31,   DECEMBER 31,
                                                           1997         1996
                                                       ------------ ------------
<S>                                                    <C>          <C>
SUMMARIZED INCOME STATEMENT DATA:
Net Interest Income................................... $   155,148  $   601,279
Provision for Loan Losses.............................       4,311       19,060
Other Income..........................................     143,435      525,241
Other Expense.........................................     203,244      788,218
Provision for Income Taxes............................      30,583      113,374
                                                       -----------  -----------
Net Income............................................ $    60,445  $   205,868
                                                       ===========  ===========
PER SHARE DATA:
Primary Net Income.................................... $      0.55  $      1.85
Fully Diluted Net Income..............................        0.55         1.82
Book Value............................................       16.02        16.14
Cash Dividends per Common Share.......................       0.185        0.720
WEIGHTED AVERAGE NUMBER OF SHARES:
Primary...............................................     109,223      111,247
Fully Diluted.........................................     111,126      114,011
AVERAGE BALANCE SHEET DATA:
Total Assets.......................................... $18,207,862  $17,047,225
Total Advances and Borrowings.........................   3,087,063    2,388,373
Shareholders' Equity..................................   1,727,040    1,719,696
</TABLE>
 
                                       12
<PAGE>
 
ILLUSTRATIVE CALCULATIONS OF STOCK CONSIDERATION, CASH CONSIDERATION, MIXED
CONSIDERATION AND STOCK AMOUNT
 
ILLUSTRATION OF CALCULATIONS OF STOCK CONSIDERATION, CASH CONSIDERATION, MIXED
  CONSIDERATION AND STOCK AMOUNT AT DIFFERENT VALUATION PERIODS MARKET VALUES
    FOR M&I COMMON STOCK (AS SUCH TERMS ARE DEFINED IN THE PROXY STATEMENT-
                                  PROSPECTUS)
 
 This illustration assumes that 9,090,232 shares of Security Common Stock will
              be outstanding at the end of the Valuation Period.
 
 
  There can be no assurance as to what the Valuation Period Market Values for
M&I Common Stock will be or what the value of M&I Common Stock to be issued in
the Merger will be at or following the Effective Time. See "THE MERGER--Merger
Consideration."
 
<TABLE>
<CAPTION>
                                                                       ELECTION 1                               ELECTION 2
                                                                   MIXED ELECTION (B)                      ALL CASH ELECTION (C)
                                              ------------------------------------------------------------ ---------------------
                                                                              VALUE OF M&I
   ALUATION PERIOD (A)V          AVERAGE                                         STOCK
    MARKET VALUE OF             PER SHARE           CASH          M&I STOCK    AMOUNT PER
 M& COMMON STOCK ($)(A)I    CONSIDERATION ($) CONSIDERATION ($) CONSIDERATION  SHARE ($)   TOTAL VALUE ($)   CONSIDERATION ($)
- -----------------------     ----------------- ----------------- ------------- ------------ --------------- ---------------------
   <S>                      <C>               <C>               <C>           <C>          <C>             <C>
     32.00...........             84.80             41.40          1.3561        43.40          84.80              84.80
     32.50...........             85.47             41.40          1.3561        44.07          85.47              85.47
     33.00...........             86.15             41.40          1.3561        44.75          86.15              86.15
     33.50...........             86.83             41.40          1.3561        45.43          86.83              86.83
     34.00...........             87.51             41.40          1.3561        46.11          87.51              87.51
     34.50...........             88.19             41.40          1.3561        46.79          88.19              88.19
     35.00...........             88.86             41.40          1.3561        47.46          88.86              88.86
     35.50...........             89.54             41.40          1.3561        48.14          89.54              89.54
     36.00...........             90.22             41.40          1.3561        48.82          90.22              90.22
     36.50...........             90.90             41.40          1.3561        49.50          90.90              90.90
     37.00...........             91.58             41.40          1.3561        50.18          91.58              91.58
<CAPTION>
                                    ELECTION 3
                              ALL STOCK ELECTION (C)
                            --------------------------
                                          VALUE OF M&I
   ALUATION PERIOD (A)V                      STOCK
    MARKET VALUE OF           M&I STOCK    AMOUNT PER
 M& COMMON STOCK ($)(A)I    CONSIDERATION  SHARE ($)
- -----------------------     ------------- ------------
   <S>                      <C>           <C>
     32.00...........          2.6499        84.80
     32.50...........          2.6299        85.47
     33.00...........          2.6106        86.15
     33.50...........          2.5919        86.83
     34.00...........          2.5737        87.51
     34.50...........          2.5561        88.19
     35.00...........          2.5390        88.86
     35.50...........          2.5223        89.54
     36.00...........          2.5061        90.22
     36.50...........          2.4903        90.90
     37.00...........          2.4750        91.58
  37.3125.........             92.00             41.40          1.3561        50.60          92.00              92.00
  37.3125.........          2.4657        92.00
  37.50...........             92.25             41.40          1.3561        50.85          92.25              92.25
  38.00...........             92.93             41.40          1.3561        51.53          92.93              92.93
  38.50...........             93.61             41.40          1.3561        52.21          93.61              93.61
  39.00...........             94.29             41.40          1.3561        52.89          94.29              94.29
  39.50...........             94.97             41.40          1.3561        53.57          94.97              94.97
  40.00...........             95.64             41.40          1.3561        54.24          95.64              95.64
  40.50...........             96.32             41.40          1.3561        54.92          96.32              96.32
  41.00...........             97.00             41.40          1.3561        55.60          97.00              97.00
  41.50...........             97.68             41.40          1.3561        56.28          97.68              97.68
  42.00...........             98.36             41.40          1.3561        56.96          98.36              98.36
  37.50...........          2.4601        92.25
  38.00...........          2.4456        92.93
  38.50...........          2.4314        93.61
  39.00...........          2.4176        94.29
  39.50...........          2.4042        94.97
  40.00...........          2.3911        95.64
  40.50...........          2.3783        96.32
  41.00...........          2.3659        97.00
  41.50...........          2.3537        97.68
  42.00...........          2.3418        98.36
</TABLE>
- ----
Assumptions:
(a) Determined based on the average final bid and ask quotations for M&I
    Common Stock for the ten consecutive trading days ending on the fifth
    calendar day prior to the Effective Time. The Valuation Period Market
    Values set forth in the chart have been included for representative
    purposes only. The Valuation Period Market Values set forth in the chart
    could be more than $42.00 or less than $32.00 per share.
(b) Mixed Elections will be given first priority.
(c) All Cash Elections and all Stock Elections will be apportioned on a pro
    rata basis. See "THE MERGER--Merger Consideration."
(1) The aggregate Merger Consideration equals 12,327,390 shares of M&I Common
    Stock and $376,335,605 cash.
(2) No oversubscriptions of either M&I Common Stock or cash.
 
                                       13
<PAGE>
 
                              THE SPECIAL MEETING
 
GENERAL
 
  This Proxy Statement-Prospectus is being furnished to shareholders of
Security in connection with the solicitation of proxies by the Board of
Directors of Security for use at the Special Meeting, including any
adjournment or postponement of the Special Meeting. The Special Meeting will
be held on Wednesday, July 9, 1997 at 10:00 a.m., Milwaukee time, at The Grand
Milwaukee Hotel, Grand Ballroom East, 4747 South Howell Avenue, Milwaukee,
Wisconsin.
 
PROPOSALS TO BE CONSIDERED
 
  The Special Meeting will be held (i) to consider and vote upon a proposal to
approve the Merger Agreement, the Merger and the transactions contemplated
thereby (the "Merger Proposal") and (ii) to transact such other business as
may properly come before the Special Meeting.
 
RECORD DATE AND VOTING RIGHT
 
  Holders of Security Common Stock at the close of business on the Record
Date, June 4, 1997, will be entitled to notice of and to vote at the Special
Meeting. Each share of Security Common Stock is entitled to one vote on each
proposal presented. As of the Record Date, there were 9,095,632 outstanding
shares of Security Common Stock entitled to vote at the Special Meeting, of
which 1,833,913 shares or approximately 20.2% were beneficially owned by
Security directors, executive officers and their affiliates. Directors and
executive officers of Security have indicated that they intend to vote their
shares in favor of the Merger Agreement.
 
  Shares of Security Common Stock representing, as of the Record Date, a
majority of the outstanding shares of Security Common Stock must be
represented in person or by proxy at the Special Meeting for a quorum to be
present. The affirmative vote of a majority of the outstanding shares of
Security Common Stock as of the Record Date is required to approve the Merger
Proposal. Abstentions and "broker non-votes" (i.e., shares held by brokers or
nominees which are represented at a meeting but with respect to which the
broker or nominee is not empowered to vote on a particular proposal) will be
treated as present for purposes of determining the presence of a quorum, but
have the same effect as a vote against the Merger Proposal.
 
VOTING; REVOCATION OF PROXIES
 
  Shares of Security Common Stock represented by a proxy properly signed and
received at or prior to the Special Meeting, unless subsequently revoked, will
be voted in accordance with the instructions in such proxy. Shares held in the
account of a participant in Security's Employee Stock Ownership Plan ("ESOP")
and in the Security 401(k) Plan ("401(k)") will be included on the proxy for
those shares registered in the name of the trustee of the ESOP and 401(k) and
will be voted by the trustee indicated in such proxy. The trustee of the ESOP
and 401(k) will solicit voting instructions from participants in both plans.
Any proxy may be revoked by the person giving it at any time prior to the
voting of the proxy by giving written notice to the Secretary of Security, by
properly executing and submitting a later-dated proxy, or by attending the
meeting and voting in person. If a proxy is signed and returned without
indicating any voting instructions, such proxy will be voted FOR the proposal
to approve the Merger Agreement. If a proxy is signed and returned with a vote
against the Merger Proposal, the shares represented by such proxy may not be
voted in favor of an adjournment to the Special Meeting. If a participant in
either Plan fails to provide timely directions as to how his allocated shares
are to be voted or if there are shares held under either Plan which have not
been allocated to any participant's account, such shares shall be voted by the
trustee or other named fiduciary in its discretion.
 
  The Security Board of Directors is not aware of any business to be acted
upon at the Special Meeting other than as described in this Proxy Statement-
Prospectus. If, however, other matters are properly brought before the Special
Meeting, the persons appointed as proxies will have discretion to vote thereon
in accordance with their best judgment.
 
 
                                      14
<PAGE>
 
SOLICITATION OF PROXIES
 
  The enclosed proxy is being solicited by the Board of Directors of Security
for use in connection with the Special Meeting. Security will bear its own
expenses in connection with the Special Meeting, except that each company
agreed to pay one half of the costs incurred in connection with the printing
and filing of this Proxy Statement-Prospectus and all Commission and other
regulatory filing fees in connection with it and with the Merger. In addition
to solicitation of proxies by mail, directors, officers and employees of
Security may make solicitation of proxies for the Special Meeting either
personally or by telephone, telegram or other forms of communication. Such
directors, officers and employees will receive no special compensation for any
solicitation.
 
  In addition, Security has retained Morrow & Company to assist in the
solicitation of proxies and in the distribution of Merger Consideration
election forms for a fee of $7,500 plus expenses. Brokerage houses, nominees,
fiduciaries and other custodians will be requested to forward soliciting
materials to beneficial owners and will be reimbursed for their customary
charges and expenses.
 
  SECURITY SHAREHOLDERS SHOULD NOT SEND STOCK CERTIFICATES WITH THEIR PROXY
CARDS. IF THE MERGER PROPOSAL IS APPROVED, AN ELECTION FORM WITH INSTRUCTIONS
WITH RESPECT TO THE SURRENDER OF SECURITY COMMON STOCK CERTIFICATES WILL BE
MAILED TO EACH HOLDER OF SECURITY COMMON STOCK 30 DAYS BEFORE THE ANTICIPATED
EFFECTIVE TIME.
 
                                      15
<PAGE>
 
                                  THE MERGER
 
  The following section of this Proxy Statement--Prospectus describes certain
aspects of the Merger. This section does not purport to be complete and is
qualified in its entirety by reference to the Merger Agreement, a copy of
which is attached as Appendix A to this Proxy Statement--Prospectus.
 
GENERAL
 
  M&I and Security have entered into the Merger Agreement which provides,
after satisfaction or waiver of all conditions described therein, for the
Merger of Security with and into M&I. The Merger will become effective at the
Effective Time, which will occur as promptly as practicable following
shareholder and regulatory approvals and the satisfaction or waiver of other
conditions contained in the Merger Agreement, but in no event prior to the
earlier of the completion of the conversion of Security Bank to M&I's data
processing systems or October 1, 1997. The parties currently anticipate that
the Merger will be completed on or about October 1, 1997. At the Effective
Time, each issued and outstanding share of Security Common Stock will be
converted into either: (i) approximately $41.40 in cash and approximately
1.3561 shares of M&I Common Stock, (ii) subject to the allocation procedures
applicable to oversubscriptions for elections to receive M&I Common Stock
described below, a number of shares of M&I Common Stock determined as
described below, or (iii) subject to the allocation procedures applicable to
oversubscriptions for elections to receive cash, an amount in cash (without
interest) determined as described below. No fractional shares of M&I Common
Stock will be issued to any Security shareholder. In lieu of fractional shares
of M&I Common Stock, former holders of Security Common Stock will receive a
cash payment upon surrender of their certificates representing Security Common
Stock in connection with the Merger, based upon the product of the fractional
share interest to which such holder would otherwise be entitled, multiplied by
the average of the final bid and asked price for a share of M&I Common Stock
as reported on the Nasdaq National Market on the five business days
immediately preceding the Effective Time. Due to the fact that the Merger
Consideration is composed of a fixed amount of M&I Common Stock and a fixed
amount of cash, some elections to receive all cash or all M&I Common Stock may
not be accommodated. See "THE MERGER--Election Procedures."
 
BACKGROUND OF THE MERGER
 
  The past several years have been a period of substantial and rapid change in
the financial services industry characterized by increasing consolidation,
intensifying competition and continued growth through acquisition by many of
the larger domestic banking organizations. During this period the Boards of
Directors of both M&I and Security have periodically reviewed their strategic
alternatives and taken various steps to maintain and enhance their long-term
competitive positions and profitability in the face of these changing
regulatory and market conditions.
 
  Since the conversion of Security from a mutual institution to a stock
institution in December 1993, several banks potentially interested in a
business combination with Security have made preliminary contacts with the
senior management of Security and Security's financial advisor, Baird. In
November 1996, Security received an inquiry from an out-of-state financial
institution, followed in early January 1997 by an informal proposal from an
in-state financial institution, to pursue a business combination with
Security.
 
  As a result of the inquiry and the informal proposal, at a meeting on
January 22, 1997, the Security Board of Directors, (including Joseph F.
Schoendorf, Jr., Chairman of the Board, William G. Schuett, Sr., President and
Chief Executive Officer, Robert A. Schaefer, Executive Vice President and
Chief Operating Officer of Security) and Roger D. Kamin, Chief Financial
Officer and Secretary of Security, met with Baird and discussed (i) the
potential of a business combination involving Security, (ii) the nature of the
informal proposal and inquiry and (iii) the process involved in pursuing a
business combination. At this meeting, the Security Board of Directors
requested that Messrs. Schoendorf, Jr., Schuett, Sr. and Schaefer and Baird
obtain further information concerning the inquiry and other possible business
combinations. During the weeks after this Board of Directors meeting, Messrs.
Schoendorf, Jr., Schuett, Sr., and Schaefer, who are also members of the
Security Board of Directors, met with Baird in order to (i) examine Security's
strategic plans and a select group of banking organizations (including M&I)
that were deemed likely to be interested in a business combination with
Security and (ii) analyze the financial ability of the select group of banking
organizations to enter into a business combination with Security.
 
                                      16
<PAGE>
 
  On February 5, 1997, Messrs. Schoendorf, Jr., Schuett, Sr. and Schaefer met
with Baird and Skadden, Arps, Slate, Meagher & Flom LLP ("Skadden, Arps"),
Security's outside legal counsel, and, among other matters, discussed the
financial ability to complete a business combination, acquisition history and
potential strategic fit with Security of a group of banking organizations
located in and out of Security's market that would be contacted concerning a
potential business combination with Security.
 
  During February 1997, Baird made contact with these potential business
combination partners (including M&I) to make inquiries as to their interest in
a business combination with Security. General discussions concerning a
potential business combination with Security between Baird and Gordon H.
Gunnlaugsson, Executive Vice President of M&I, continued throughout the first
half of February 1997. On February 19, 1997, the Security Board of Directors
met and reviewed in detail with Messrs. Schoendorf, Jr., Schuett, Sr.,
Schaefer and Kamin, Skadden, Arps and Baird (i) the discussions and contacts
that had been made with banking organizations regarding a possible business
combination (including discussions with M&I), (ii) the financial condition of
such banking organizations and potential synergies that could be achieved in a
business combination with Security, and (iii) the likelihood of such banking
organizations consummating a business combination with Security. Following the
discussion at the February 19 meeting, the Security Board of Directors
authorized Messrs. Schoendorf, Jr., Schuett, Sr., Schaefer and Kamin and Baird
to pursue discussions with M&I and other possible entities regarding a
possible business combination with a view toward further consideration by the
Security Board of Directors if a proposal with respect to such a transaction
were developed.
 
  On February 28, 1997, a form of merger agreement was sent to M&I and certain
other potential acquirors. Each of the potential acquirors was requested to
provide Security with a proposal by the beginning of the week of March 11,
1997 for a potential business combination with Security using the form of
merger agreement previously sent to them as a basis for such proposal.
 
  On March 3, 1997, Mr. James B. Wigdale, Chairman of the Board and Chief
Executive Officer of M&I, and Mr. Gunnlaugsson met with Messrs. Schoendorf,
Jr., Schuett, Sr., and Schaefer to discuss the financial condition of M&I and
Security, the operating philosophies of each company and possible synergies
that could be achieved in a business combination. M&I began its legal and
financial due diligence the following day which continued through March 14,
1997. During the month of February 1997 until the first week of March 1997,
certain other potential acquirors also conducted financial and legal due
diligence on Security and met with Security's senior management in connection
with their due diligence.
 
  Security began its legal and financial due diligence on M&I and certain
other institutions the week of March 3, 1997 and continued through March 13,
1997. On March 8, 1997, Security and its outside legal counsel received
proposed merger agreements from M&I and another potential acquiror, each
without pricing information.
 
  On March 12, 1997, Security received a written proposal from M&I for a
business combination with Security in which the Security shareholders would
receive an aggregate of 12,049,722 shares of M&I Common Stock and $384.5
million in cash. Security did not receive on March 12, 1997 any other final
proposals from other potential acquirors.
 
  At a meeting on March 12, 1997, the Security Board of Directors met to
review the terms of the proposal from M&I, as well as the status of the
discussions with other potential acquirors. At this meeting, Messrs.
Schoendorf, Jr., Schuett, Sr., Schaefer and Kamin together with
representatives of Baird and Skadden, Arps (i) reviewed in detail the M&I
proposal and the terms of M&I's proposed merger agreement and (ii) discussed
the likelihood of receiving a formal proposal from other potential business
combination partners with a value to the holders of Security Common Stock
greater than the M&I proposal. Based on the results of these discussions, the
Security Board of Directors determined it was in the best interest of the
holders of Security Common Stock to pursue the M&I proposal and authorized
Messrs. Schoendorf, Jr., Schuett, Sr., Schaefer and Kamin and Skadden, Arps
and Baird to continue discussions with M&I in order to finalize the terms of a
merger agreement.
 
                                      17
<PAGE>
 
  Following the March 12 Security Board of Directors meeting, discussions
related to finalizing the proposed merger agreement continued between M&I's
and Security's respective legal counsel and Baird. In the afternoon of March
13, Messrs. Schoendorf, Jr., Schuett, Sr., Schaefer and Kamin and the Security
Board of Directors met informally with Baird and Skadden, Arps to discuss and
review the status of the negotiations with M&I and the terms of the proposed
Merger Consideration of the M&I proposal.
 
  On March 14, senior management of M&I and Security, together with their
respective legal counsel and financial advisors, finalized the terms of the
Merger Agreement to be presented to the Security Board of Directors. In the
final negotiations of the Merger Agreement, the aggregate cash was decreased
and the initial exchange ratio was increased, thereby increasing the number of
shares of M&I Common Stock included in the Merger Consideration and increasing
the nominal value of the Merger Consideration by approximately $2 million
(based on the closing stock price of M&I Common Stock on March 14, 1997 of
$37.3125 per share). Pursuant to final Merger Agreement, holders of Security
Common Stock would receive an aggregate of 12,327,390 shares of M&I Common
Stock and $376.3 million in cash. On March 14, the Security Board of Directors
held a meeting to discuss at length and review, with the assistance of Baird
and Skadden, Arps, the Merger Agreement and the transactions contemplated
thereby. At such meeting, the Security Board of Directors reviewed in detail
with Skadden, Arps and senior management the terms of the Merger and the
Merger Agreement and the resolution of the open issues discussed at the
meetings on March 12 and March 13 as well as the fiduciary duties of the
Security Board of Directors. Baird delivered to the Security Board of
Directors its oral opinion (subsequently confirmed in writing) that, as of
such date, the Merger Consideration was fair, from a financial point of view,
to the holders of Security Common Stock (other than M&I and its affiliates).
THE OPINION OF BAIRD IS ATTACHED HERETO AS APPENDIX C AND HOLDERS OF SECURITY
COMMON STOCK ARE ENCOURAGED TO READ THAT OPINION CAREFULLY AND IN ITS
ENTIRETY. See "THE MERGER--Opinion of Financial Advisor to Security."
Following the Security Board of Directors review and discussion of the
definitive terms of the transaction, the opinion of Baird and numerous other
relevant factors (described below in "THE MERGER--Reasons for the Merger;
Security Board Recommendation"), the Security Board of Directors, by unanimous
vote of all directors, authorized and approved the Merger Agreement and the
transactions contemplated thereby and determined that the Merger Agreement be
submitted to a vote of Security's shareholders and that the Security Board of
Directors recommend that such shareholders approve and adopt the Merger
Agreement. The Merger Agreement was executed by both parties shortly
thereafter.
 
REASONS FOR THE MERGER; SECURITY BOARD RECOMMENDATION
 
  In reaching its determination, the Security Board of Directors consulted
with Skadden, Arps, Slate, Meagher & Flom LLP, Security's outside legal
counsel, with respect to the legal duties of the Security Board of Directors,
regulatory matters, tax matters and the Merger Agreement and issues related
thereto. The Security Board of Directors also consulted with Baird, Security's
financial advisor, with respect to the financial aspects and fairness of the
Merger Consideration. The Security Board of Directors also consulted with
senior management on all of the foregoing issues as well as more conceptual
issues and advantages of the proposed Merger. The Security Board of Directors
considered a number of factors, without assigning any specific or relative
weight to the consideration of such factors. The material factors considered
were:
 
  (i) Information concerning the businesses, earnings, operations, financial
      condition, prospects, capital levels and asset quality of Security and
      M&I, both individually and as combined. In particular, the Security
      Board of Directors focused on the strategic fit of the business lines
      and the operating philosophies of the two institutions, and the
      significant contribution of non-interest income and opportunity for
      growth provided by M&I's data processing and trust operations. M&I's
      non-interest income as a percentage of its average assets was
      significantly higher than that of a select group of comparable
      companies and Security (see "THE MERGER--Opinion of Financial Advisor
      to Security");
 
  (ii) The advantages of a combination with another Wisconsin-based
       institution, including the building of market share without undue
       market concentration concerns, enhanced exposure to commercial and
       consumer banking markets, and the opportunities for increased
       efficiencies and significant cost savings from a combination within
       the Wisconsin market resulting in increased profitability of the
       combined entity over time as opposed to a possible out-of-market
       business combination;
 
                                      18
<PAGE>
 
  (iii) The current and prospective economic and competitive environments
        facing Security and other financial institutions characterized by
        intensifying competition from both banks and nonbank financial
        services organizations, the increasing necessity for strong fee-based
        income producing components within a bank holding company, and the
        growing costs associated with regulatory compliance in the banking
        industry;
 
  (iv) Security's dependence on earnings from retail banking, which have been
       subject to increasing margin pressure, and countervailing benefits
       associated with M&I's complementary strength in commercial banking and
       significant percentage of fee-based income not subject to such margin
       pressure;
 
  (v) The high costs of technology and new facilities required in order to
      grow deposits in light of the fact that deposit growth for Security and
      the banking industry in general has been difficult and such funding
      limitations would hamper Security's long-term asset growth;
 
  (vi) Security's concentration of first and second mortgages and the
       interest rate risk and prepayment risk associated therewith as
       compared to more diverse income generating assets and operations
       maintained by other banking institutions (including M&I);
 
  (vii) The belief that following the Merger, M&I would be well positioned to
        grow through possible future acquisitions or expansions while at the
        same time not being so large as to reduce its attractiveness as a
        possible acquisition candidate;
 
  (viii) The belief that the Merger would result in shareholders of Security
         receiving stock in a high quality combined company that should
         benefit shareholders through enhanced operating efficiencies and
         better penetration of commercial and consumer banking markets;
 
  (ix) The opinion by Baird that as of the date of such opinion, the Merger
       Consideration is fair, from a financial point of view, to the holders
       of Security Common Stock (other than M&I and its affiliates) (see "THE
       MERGER--Opinion of Financial Advisor to Security");
 
  (x) A comparison of the legal terms of the Merger Agreement and the other
      documents relating to the Merger to the terms customarily seen in
      similar transactions;
 
  (xi) The continuing influence of certain of Security's directors and
       executive management personnel in the combined institution and, in
       particular, the continuing influence of Security's management in
       retail banking; and
 
  (xii) The impact of the Merger on Security's employees in terms of working
        environment, career opportunities as well as layoffs that would
        likely result in a transaction with M&I, the impact on Security's
        depositors and customers in terms of the wider range of products and
        services that will be available from a strong and sound combined
        institution, and on the communities which Security serves in terms of
        the enhanced strength and accessibility of the combined Wisconsin
        franchise.
 
  The foregoing discussion of the information and factors considered by the
Security Board of Directors is not intended to be exhaustive but is believed
to include all material factors considered by the Security Board of Directors.
Throughout its deliberations, the Security Board of Directors received the
advice of its outside legal counsel. After deliberating with respect to the
Merger and the other transactions contemplated by the Merger Agreement,
considering, among other things, the information and factors described above
(including reliance on the opinion of Baird), the Security Board of Directors
concluded that the Merger is fair to, and in the best interest of its
shareholders. In reaching this conclusion, the Security Board of Directors did
not assign relative or specific weights to the above information and factors
or determine that any information or factor was of particular importance. A
determination of various weightings would, in the view of the Security Board
of Directors, be impractical. Rather, the Security Board of Directors viewed
its position and recommendations as being based on the totality of the
information and factors presented to and considered by it. In addition,
individual members of the Security Board of Directors may have given different
weight to different information and factors.
 
  FOR THE REASONS DESCRIBED ABOVE, THE SECURITY BOARD OF DIRECTORS HAS
DETERMINED THAT THE TERMS OF THE MERGER ARE FAIR TO, AND IN THE BEST INTERESTS
OF, SECURITY'S SHAREHOLDERS. ACCORDINGLY, THE SECURITY BOARD OF DIRECTORS
UNANIMOUSLY APPROVED THE MERGER AGREEMENT AND RECOMMENDS THAT THE SHAREHOLDERS
OF SECURITY VOTE FOR APPROVAL OF THE MERGER AGREEMENT.
 
                                      19
<PAGE>
 
  M&I. The M&I Board of Directors has determined that the Merger is desirable
since it enhances M&I's market position in Wisconsin, creates the opportunity
for significant cost savings, and is attractive from a financial viewpoint.
M&I expects that after the Merger, it will have the largest market share in
Wisconsin based on deposits (approximately 19.1%) and will also have the
largest market share of deposits in the metro Milwaukee area (approximately
24.4%). Because of the significant market overlap of the operations of M&I and
Security, M&I anticipates approximately $31.8 million in cost savings by 1999.
In addition, the transaction is expected to have no significant impact on
M&I's earnings in 1997, and to be accretive in 1998 and 1999. M&I expects
earnings accretion of appproximately 3.8% in 1998 and 6.6% in 1999.
 
OPINION OF FINANCIAL ADVISOR TO SECURITY
 
  The Board of Directors of Security retained Baird to act as its financial
advisor and to render its opinion as to whether or not the Merger
Consideration is fair, from a financial point of view, to the holders of
Security Common Stock (other than M&I and its affiliates). On March 14, 1997,
Baird delivered its opinion to the Board of Directors of Security that, as of
such date, the Merger Consideration was fair, from a financial point of view,
to such holders.
 
  THE FULL TEXT OF BAIRD'S OPINION, DATED MARCH 14, 1997, WHICH SETS FORTH THE
ASSUMPTIONS MADE, GENERAL PROCEDURES FOLLOWED, MATTERS CONSIDERED AND
LIMITATIONS ON THE SCOPE OF REVIEW UNDERTAKEN BY BAIRD IN RENDERING ITS
OPINION, IS ATTACHED AS APPENDIX C TO THIS PROXY STATEMENT-PROSPECTUS AND IS
INCORPORATED HEREIN BY REFERENCE. BAIRD'S OPINION IS DIRECTED ONLY TO THE
FAIRNESS, AS OF THE DATE OF THE OPINION AND FROM A FINANCIAL POINT OF VIEW, OF
THE MERGER CONSIDERATION TO THE HOLDERS OF SECURITY CAPITAL CORPORATION COMMON
STOCK (OTHER THAN M&I AND ITS AFFILIATES) AND DOES NOT CONSTITUTE A
RECOMMENDATION TO ANY HOLDER OF SECURITY COMMON STOCK AS TO HOW SUCH HOLDER
SHOULD VOTE WITH RESPECT TO THE MERGER. THE SUMMARY OF BAIRD'S OPINION SET
FORTH BELOW IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE FULL TEXT OF SUCH
OPINION ATTACHED HERETO AS APPENDIX C. HOLDERS OF SECURITY COMMON STOCK ARE
URGED TO READ THE OPINION CAREFULLY IN ITS ENTIRETY.
 
  In conducting its investigation and analysis and in arriving at its opinion,
Baird reviewed such information and took into account such financial and
economic factors as deemed relevant under the circumstances. In that
connection, Baird among other things: (i) reviewed certain internal
information, primarily financial in nature, including projections concerning
the business and operations of Security and M&I furnished to Baird for
purposes of its analysis, as well as publicly available information including,
but not limited to, Security's and M&I's recent filings with the Commission
and equity analyst research reports prepared by various investment banking
firms including Baird; (ii) reviewed the draft Merger Agreement in the form
presented to the Security's Board of Directors; (iii) compared the historical
market prices and trading activity of Security Common Stock and M&I Common
Stock with those of certain other publicly traded companies Baird deemed
relevant; (iv) compared the financial position and operating results of
Security and M&I with those of other publicly traded companies Baird deemed
relevant; (v) compared the proposed financial terms of the Merger with the
financial terms of certain other business combination transactions involving
thrift institutions that Baird deemed relevant; and (vi) reviewed the
potential pro forma effects of the Merger on M&I. Baird held discussions with
members of Security's and M&I's respective senior management concerning
Security's and M&I's historical and current financial condition and operating
results, as well as the future prospects of Security and M&I, respectively. As
a part of its engagement, Baird was requested to and did solicit third party
indications of interest in acquiring Security. Baird also considered such
other information, financial studies, analysis and investigations and
financial, economic and market criteria as Baird deemed relevant for the
preparation of its opinion. The Merger Consideration was determined by
Security and M&I in arm's-length negotiations. Security did not place any
limitation upon Baird with respect to the procedures followed or factors
considered by Baird in rendering its opinion.
 
 
                                      20
<PAGE>
 
  In arriving at its opinion, Baird assumed and relied upon the accuracy and
completeness of all of the financial and other information that was publicly
available or provided to it by or on behalf of Security and M&I, and was not
engaged to independently verify any such information. Baird assumed, with
Security's consent, (i) all material assets and liabilities (contingent or
otherwise, known or unknown) of Security and M&I are as set forth in their
respective financial statements, (ii) the Merger will be accounted for under
the purchase method of accounting and (iii) the Merger will be consummated in
accordance with the terms of the Merger Agreement without any amendment
thereto or waiver by Security or M&I of any condition to their respective
obligations. Baird has also assumed that the financial forecasts examined by
it were reasonably prepared on bases reflecting the best available estimates
and good faith judgments of Security's and M&I's respective senior management
as to future performance of Security and M&I, respectively. Baird did not
undertake or obtain an independent evaluation or appraisal of any of the
assets or liabilities (contingent or otherwise) of Security or M&I, nor did it
make a physical inspection of the properties or facilities of Security or M&I.
Baird's opinion necessarily was based upon economic, monetary and market
conditions as they existed and could be evaluated on the date of its opinion,
and did not predict or take into account any changes which may occur, or
information which may become available, after the date thereof. Furthermore,
Baird expressed no opinion as to the price or trading range at which shares of
the Security's or M&I's securities would trade following the date of such
opinion.
 
  The following is a summary of the material financial analyses performed by
Baird in connection with rendering its opinion.
 
  Analysis of Security Valuation Multiples. Baird reviewed the terms of the
proposed Merger, including the form of the Merger Consideration, the proposed
method of accounting, the closing price of M&I Common Stock as of March 14,
1997, and the resulting indicated value of the Merger per share of Security
Common Stock. The proposed form of Merger Consideration permitted the
opportunity for each holder of Security Common Stock to receive M&I Common
Stock, cash, or a combination thereof, subject to the limitations described
under "THE MERGER--Merger Consideration." The proposed method of accounting
for the Merger was the purchase method. The indicated value for the Merger was
$92 per share of Security Common Stock (the "Indicated Value"), based upon the
closing price of M&I Common Stock on March 14, 1997. The Indicated Value was
necessarily dependent on the price of M&I Common Stock at a specific time.
 
  Baird calculated multiples of the Indicated Value to Security's earnings per
share ("EPS") (adjusted for the special assessment levied on all Savings
Association Insurance Fund members to recapitalize the insurance fund (the
"Special Assessment")) for the year ended December 31, 1996 ("Adjusted 1996
Earnings"), Security management's estimates of Security's 1997 EPS ("Projected
1997 Earnings") and Security's reported book value per share as of December
31, 1996 ("Book Value"). Baird also calculated the implied premium to deposits
indicated by the Merger (defined as (i) Aggregate Consideration (as defined in
the Merger Agreement) plus the value of outstanding options to purchase
Security Common Stock, less Book Value (such amount being the "Adjusted
Aggregate Consideration"), divided by (ii) total deposits as of December 31,
1996) and the implied premium to "core" deposits indicated by the Merger
(defined as the Adjusted Aggregate Consideration divided by total deposits as
of December 31, 1996 (excluding brokered deposits and jumbo certificates of
deposit)). These calculations resulted in multiples of Indicated Value to EPS
("P/E Ratios") of 20.5x based on Adjusted 1996 Earnings and 15.2x based on
Projected 1997 Earnings and a multiple of Indicated Value to Book Value of
1.582x. These calculations also resulted in an implied deposit premium of
15.2% and an implied core deposit premium of 19.6%.
 
  Analysis of Publicly Traded Companies Comparable to Security. Baird reviewed
certain publicly available financial information as of the most recently
reported period and stock market information as of March 13, 1997 for certain
publicly traded companies which Baird deemed relevant. These companies
included Advantage Bancorp, Inc., Anchor BanCorp Wisconsin, Inc., CitFed
Bancorp, Inc., First Financial Corporation, FirstFederal Financial Services
Corp., First Indiana Corporation, First Federal Capital Corp., Great Financial
Corporation, Jefferson Savings Bancorp, Inc., MAF Bancorp, Inc., Peoples
Heritage Financial Group, Inc., St. Paul Bancorp,
 
                                      21
<PAGE>
 
Inc., St. Francis Capital Corporation, Standard Financial, Inc. and Washington
Federal, Inc. (the "Comparable Companies"). The data described below with
respect to the Comparable Companies consists of the median data for such group
as of the most recently reported period and are compared to Security Capital
Corporation's Common Stock price (both based on closing prices as of March 13,
1997) and Security's financial and operating information, as reported, as of
December 31, 1996.
 
  Baird noted that the ratios of the closing price of Security Common Stock to
the latest twelve month ("LTM") earnings per share, "core" earnings per share
(as defined by SNL Datasource, Inc. ("SNL Datasource") to exclude
extraordinary items and the after-tax portion of gains on sale and
nonrecurring items), projected 1997 earnings as estimated by Security senior
management for Security and as derived from equity research analysts' reports
as reported by I/B/E/S for Comparable Companies and stated book value per
share were 23.2x, 18.0x, 14.0x and 1.453x, respectively, for Security and was
22.7x, 17.2x, 12.4x and 1.650x, respectively, for the Comparable Companies.
The assets and equity reported for Security were approximately $3.66 billion
and $568 million compared to approximately $2.65 billion and $218 million for
the Comparable Companies. Baird also noted ratios of LTM earnings items to
average assets for (i) net interest income of 3.55% for Security and 2.89% for
the Comparable Companies, (ii) provisions for loan losses of 0.11% for
Security and 0.06% for the Comparable Companies, (iii) other (non-interest)
income of 0.38% for Security and 0.46% for the Comparable Companies, (iv) G&A
expenses of 2.10% for Security and 2.12% for the Comparable Companies, (v) net
income (i.e., return on average assets ("ROAA") of 0.99% for Security and
0.72% for the Comparable Companies) and (vi) ratio of LTM earnings to average
equity ("ROAE") of 6.02% for Security and 8.81% for the Comparable Companies.
Baird also noted LTM annual growth rates in assets, loans and deposits of
10.8%, 9.6% and 4.9% for Security and 16.1%, 9.6% and 8.9% for the Comparable
Companies. Baird noted that these figures for the Comparable Companies
included growth due to merger activity as well as internal growth. Baird noted
capital-to-assets and tangible capital-to-assets ratios of 15.53% (for both
measures) for Security and 8.42% and 7.57%, respectively, for the Comparable
Companies. Baird also noted certain asset quality ratios including
nonperforming assets and 90 days and greater delinquent assets as a ratio to
total assets and reserves to loan value ratios of 0.11% and 1.47%,
respectively, for Security and 0.52% and 0.82%, respectively, for the
Comparable Companies.
 
  Discounted Dividend Analysis. Baird performed a discounted dividend analysis
of Security on a stand alone basis using Security management's projections for
the two and one-half years ending June 30, 1999, without taking into account
any cost savings and synergies that may be realized following the Merger. In
that analysis, Baird assumed terminal value multiples of 8.0x to 14.0x such
projected earnings and discount rates of 14% to 16%. Such analysis produced
implied values of Security Common Stock of $61.84 to $84.85. Baird also
performed a discounted dividend analysis of Security assuming that the cost
savings and synergies that M&I management estimates will be realized,
beginning after the first year of such projections. Using the same terminal
value multiples and discount rates, the analysis produced implied values of
Security Common Stock of $74.53 to $97.54. The above analyses assumed
maintenance of a six percent equity-to-asset ratio in determining the amount
of dividend payouts. Baird noted that the discounted dividend analysis was
included because it is a widely used valuation methodology, but noted that the
results of such methodology are highly dependent upon numerous assumptions
that must be made, including earnings growth rates, dividend payout rates,
terminal values and discount rates.
 
  Analysis of Selected Comparable Transactions. Baird reviewed certain
information relating to four groups of transactions involving business
combinations of thrift institutions announced from January 1, 1996 through
March 6, 1997: (i) a group of 201 business combinations, representing all such
announced transactions as reported by SNL Datasource (the "Total Group"); (ii)
the 11 business combinations included in the Total Group with a total
transaction value in excess of $500 million (the "Large Transaction Group");
(iii) the 44 business combinations included in the Total Group involving
acquired thrifts with a capital-to-assets ratio in excess of 12.5% (the "High
Ratio Group"); (iv) the eight business combinations with total transaction
value in excess of $250 million included in the Total Group classified by SNL
Datasource as "in-market" transactions (the "In-
 
                                      22
<PAGE>
 
Market Group"). The business combinations in the Large Transaction Group, the
High Ratio Group and the In-Market Group are listed in the table below:
 
<TABLE>
<CAPTION>
             ACQUIRER                                  TARGET
 <S>                                <C>
      Large Transaction Group
      -----------------------
      Washington Mutual, Inc.           Great Western Financial Corporation
          Summit Bancorp.                     Collective Bancorp Inc.
  Mercantile Bancorporation Inc.          Roosevelt Financial Group, Inc.
        ABN AMRO Holding NV            Standard Federal Bancorporation, Inc.
         HSBC Holdings Plc                    First FS&LA of Rochester
 MacAndrews & Forbes Holdings Inc.             Cal Fed Bancorp, Inc.
      Washington Mutual, Inc.                 Keystone Holdings, Inc.
    Union Planters Corporation                 Leader Financial Corp.
   Republic New York Corporation               Brooklyn Bancorp Inc.
      NationsBank Corporation                    CSF Holdings, Inc.
      First Union Corporation                Coral Gables Fedcorp, Inc.
         High Ratio Group
         ----------------
          MASSBANK Corp.                     Glendale Co-Operative Bank
          CFX Corporation                      Portsmouth Bank Shares
  Commercial Federal Corporation             Investors Federal Savings
        Mutual Savings Bank         First Federal Bancshares of Eau Claire, Inc.
      PennFirst Bancorp, Inc.                 Troy Hill Bancorp, Inc.
   Berkshire County Savings Bank           Great Barrington Savings Bank
       Peoples Bancorp, Inc.                Russell Federal Savings Bank
      Charter Financial, Inc                 Home Federal Savings Bank
    Northwest Savings Bank, MHC               Bridgeville Savings Bank
   Jefferson Savings Bancorp Inc                L&B Financial, Inc.
      First Union Corporation                Home Financial Corporation
      Western Ohio Financial             Seven Hills Financial Corporation
            Corporation
     Pinnacle Banc Group, Inc                 Financial Security Corp.
     Security Banc Corporation                 Third Financial Corp.
     ISB Financial Corporation                Jefferson Bancorp, Inc.
    Camco Financial Corporation         First Ashland Financial Corporation
    First Southern Bancorp Inc.           Lincoln Financial Bancorp, Inc.
   First Chicago NBD Corporation              Barrington Bancorp, Inc.
    One Valley Bancorp of West               CSB Financial Corporation
           Virginia, Inc.
     Capital Corp of the West          Town & Country Finance & Thrift, Inc.
 Standard Federal Bancorporation,                Bell Bancorp, Inc.
                Inc.
     Approved Financial Corp.        First Security Federal Savings Bank, Inc.
         MAF Bancorp, Inc.                       N.S. Bancorp, Inc.
    Great Financial Corporation                  LFS Bancorp, Inc.
     BancSecurity Corporation            Marshalltown Financial Corporation
     The Dime Savings Bank of                 Conestoga Bancorp, Inc.
           Williamsburgh
   First Alliance Bancorp, Inc.               Premier Bancshares Inc.
    D & N Financial Corporation             Macomb Federal Savings Bank
       Security First Corp.               First Kent Financial Corporation
   Regions Financial Corporation    First Federal Bank of Northwest Georgia FSB
 American National Bankshares Inc.              Mutual Savings Bank
        Fifth Third Bancorp              Kentucky Enterprise Bancorp, Inc.
   First Midwest Financial, Inc                  Iowa Bancorp, Inc
    United Carolina Bancshares            Seaboard Savings Bank, Inc. SSB
            Corporation
</TABLE>
 
                                       23
<PAGE>
 
<TABLE>
<CAPTION>
               ACQUIRER                                  TARGET
<S>                                      <C>
     High Ratio Group (Continued)
     ----------------------------
          Essex Bancorp Inc.                       Home Bancorp, Inc.
    Roosevelt Financial Group Inc.            Kirksville Bancshares, Inc.
         New Era Bancorp Inc.              St Francois County Financial Corp.
              FCNB Corp.                          Laurel Bancorp, Inc.
Independence Community Bank Corporation         Bay Ridge Bancorp, Inc.
      First Federal Capital Corp.              Rock Financial Corporation
    Roosevelt Financial Group Inc.                 WSB Bancorp, Inc.
         CitFed Bancorp, Inc.                   PSB Holdings Corporation
     Brittany Savings Corporation          United Savings & Loan Association
        First Union Corporation                Coral Gables Fedcorp Inc.
            In-Market Group
            ---------------
            Summit Bancorp.                        Collective Bancorp
        Sovereign Bancorp, Inc.                      Bankers Corp.
    Mercantile Bancorporation Inc.          Roosevelt Financial Group, Inc.
        First Union Corporation                  Center Financial Corp.
        First Union Corporation                Home Financial Corporation
      Union Planters Corporation                 Leader Financial Corp.
     Republic New York Corporation               Brooklyn Bancorp Inc.
        First Union Corporation                Coral Gables Fedcorp, Inc.
</TABLE>
 
  Based on the closing market price of M&I Common Stock on March 14, 1997,
Baird calculated that: (i) the ratio of Indicated Value to Security's Book
Value equaled 158.2%, compared with high, median and low price-to-book ratios
of 305.7%, 146.0% and 64.0% for the Total Group, 271.8%, 183.7% and 139.4% for
the Large Transaction Group, 194.6%, 127.3% and 104.3% for the High Ratio
Group, and 230.4%, 166.4% and 106.0% for the In-Market Group; (ii) the ratio
of Indicated Value to Security's tangible book value equaled 158.2%, compared
with high, median and low price-to-tangible book ratios of 381.9%, 148.1% and
64.0% for the Total Group, 308.0%, 183.7% and 139.4% for the Large Transaction
Group, 381.9%, 127.8% and 104.3% for the High Ratio Group, and 256.6%, 173.8%
and 106.0% for the In-Market Group; (iii) the multiple of Indicated Value to
Adjusted 1996 Earnings of Security equaled 20.5x, compared with high, median
and low P/E Ratios based on LTM earnings (adjusted for the Special Assessment,
where applicable) of 65.5x, 17.4x and 7.7x for the Total Group, 35.2x, 14.2x
and 11.4x for the Large Transaction Group, 65.5x, 21.9x and 11.3x for the High
Ratio Group, and 17.3x, 14.7x and 13.1x for the In-Market Group; and (iv) the
implied "core" deposit premium indicated by the Merger equaled 19.6%, compared
with high, median, low premiums to "core" deposits of 34.2%, 6.4% and (1.9%)
for the Total Group, 19.4%, 9.8% and 3.9% for the Large Transaction Group,
34.2%, 7.5% and 3.2% for the High Ratio Group, and 18.5%, 9.4% and 3.6% for
the In-Market Group.
 
  Baird also compared the above ratios for the Large Transaction Group with
the above ratios for Security, as adjusted after giving effect to the
theoretical dividend (the "Theoretical Dividend") by Security sufficient to
cause Security's capital-to-asset ratios to become equal to the median
capital-to-assets ratio for the Large Transaction Group. After adjusting for
the Theoretical Dividend, Baird calculated that: (i) the ratio of Indicated
Value to Security's reported book value equaled 266.9%, compared with high,
median and low price-to-book ratios of 271.8%, 183.7% and 139.4% for the Large
Transaction Group; (ii) the ratio of Indicated Value to Security's tangible
book value equaled 266.9% compared with high, median and low price-to-tangible
book ratios of 308.0%, 183.7% and 139.4% for the Large Transaction Group;
(iii) the multiple of Indicated Value to Adjusted 1996 Earnings of Security
equaled 20.0x, compared with high, median and low P/E Ratios based on LTM
earnings (adjusted for the Special Assessment, where applicable) of 35.2x,
14.2x and 11.4x for the Large Transaction Group.
 
                                      24
<PAGE>
 
  Baird also analyzed the premiums represented by the Indicated Value over the
market price of Security Common Stock as of March 14, 1997, and one month,
three months and one year prior thereto, compared to the prices paid in the
Large Transaction Group of comparable business combinations relative to the
market value of the acquired company's equity one day, one month, three
months, and one year prior to the announcement date of such transaction. Such
analysis yielded premiums of 8.9%, 15.9%, 25.6% and 68.0% for Security,
compared to median premiums of 12.6%, 27.4%, 28.0% and 59.3% for the Large
Transaction Group.
 
  Analysis of M&I. In order to assess the relative public market valuation of
the M&I Common Stock to be issued in the Merger, Baird (i) reviewed certain
publicly available financial information as of the most recently reported
period and stock market information as of March 13, 1997 for M&I and certain
selected publicly traded companies which Baird deemed relevant and (ii)
performed a discounted earnings analysis of M&I. Such comparable companies
consisted of AmSouth Bancorporation, Bancorp Hawaii Inc., BanPonce
Corporation, Compass Bancshares Inc., Crestar Financial Corporation, Central
Fidelity Banks Inc., First American Corporation, First Empire State
Corporation, Fifth Third Bancorp, First of America Bank Corporation, First
Security Corporation, Firstar Corporation, First Tennessee National
Corporation, Huntington Bancshares Incorporated, Mercantile Bancorporation
Inc., Northern Trust Corporation, Old Kent Financial Corporation, Regions
Financial Corporation, Signet Banking Corporation, Southern National
Corporation, SouthTrust Corporation, Star Banc Corporation, Summit Bancorp,
UnionBanCal Corporation, and Union Planters Corporation (the "M&I Comparable
Companies"). The data described below with respect to the M&I Comparable
Companies consists of median data for such group and are compared to M&I
Common Stock price (both based on closing prices as of March 13, 1997) and
M&I's financial and operating information as reported as of December 31, 1996.
 
  Baird noted that the ratios of the closing price of M&I Common Stock to LTM
earnings per share, projected 1997 and projected 1998 earnings (as estimated
by M&I senior management for M&I and as derived from equity research analysts'
reports as reported by I/B/E/S for the M&I Comparable Companies), and stated
book value were 18.3x, 15.4x, 14.2x and 2.767x, respectively, for M&I as
compared to 15.8x, 13.5x, 12.0x and 2.262x for the M&I Comparable Companies.
The assets and equity reported for M&I were approximately $14.8 billion and
$1.26 billion compared to approximately $18.4 billion and $1.40 billion for
the M&I Comparable Companies. Baird also noted ratios of LTM earnings items to
average assets for (i) net interest income of 3.70% for M&I and 3.93% for the
M&I Comparable Companies, (ii) provisions for loan losses of 0.11% for M&I and
0.32% for the M&I Comparable Companies, (iii) non-interest income of 3.58% for
M&I and 1.48% for the M&I Comparable Companies, (iv) non-interest expense of
4.98% for M&I and 3.37% for the M&I Comparable Companies, (v) net income (or
return on average assets ("ROAA")) of 1.49% for M&I and 1.18% for the M&I
Comparable Companies and (vi) ratio of LTM earnings to average equity ("ROAE")
of 15.88% for M&I and 15.50% for the M&I Comparable Companies. Baird also
noted LTM growth in assets, loans and deposits of 10.6%, 5.5% and 6.5% for M&I
and 6.1%, 7.5% and 6.3% for the M&I Comparable Companies. Baird noted capital-
to-assets and tangible capital-to-assets ratios of 8.54% and 8.09%,
respectively, for M&I and 7.88% and 7.18%, respectively, for the M&I
Comparable Companies. Baird also noted certain asset quality ratios, including
nonperforming assets to assets and reserves to nonperforming loan ratios of
0.46% and 251.5%, respectively, for M&I and 0.41% and 315.4%, respectively,
for the M&I Comparable Companies. Baird also analyzed the contribution of
M&I's data processing operation, M&I Data Services Division, to the public
market valuation of M&I and noted that, after considering the effects of such
contribution, the above pricing ratios were generally similar to the
corresponding financial data for the M&I Comparable Companies.
 
  Baird performed a discounted earnings analysis of M&I on a stand-alone basis
using M&I management's projections of future earnings for the two-year period
ending December 31, 1998. Baird estimated terminal values for M&I using 7.6%
to 9.6% perpetual growth rates for 1998 net income as projected by M&I senior
management, and discount rates of 14% to 16%. Such analysis resulted in
implied values of M&I Common Stock ranging from $25.03 to $45.34. Baird noted
that the discounted earnings analysis was included because it is a widely used
valuation methodology, but noted that the results of such methodology are
highly dependent upon the numerous assumptions that must be made, including
earnings growth ratios, dividend payout rates, terminal values and discount
rates.
 
                                      25
<PAGE>
 
  Pro Forma Merger Analysis. Baird prepared a pro forma analysis of the
financial impact of the Merger. Using earnings estimates for Security
(prepared by Security management) and M&I (prepared by M&I management), Baird
compared M&I's earnings per share and book value on a stand alone basis to the
earnings per share of common stock and book value of the combined companies on
a pro forma basis. In conducting this analysis, Baird assumed that certain
effects of the Merger would be realized as estimated by Security and M&I
management, including cost savings, operating synergies, transaction and
severance costs and tax effects resulting from the Merger. This analysis
indicated that the Merger would be accretive to M&I's pro forma earnings per
share in calendar years 1997 and 1998 and would be accretive to M&I's pro
forma book value in both years.
 
  Stock Trading Analysis. Baird reviewed the historical trading prices and
volume of Security Common Stock and M&I Common Stock on a daily basis from
January 1, 1997 to March 13, 1997 and on a weekly basis from March 15, 1996 to
March 10, 1997. Baird also compared the relative trading prices of the
Security Common Stock and M&I Common Stock to the NASDAQ Bank Index over the
previous three years.
 
  The foregoing summary does not purport to be a complete description of the
analyses performed by Baird. The preparation of a fairness opinion is a
complete process and is not susceptible to partial analysis or a summary
description. Baird believes that its analyses must be considered as a whole
and that selecting portions of such analyses without considering all factors
and analyses would create an incomplete view of the processes underlying its
opinion. In its analyses, Baird relied upon numerous assumptions made by
senior management of Security and M&I with respect to industry performance,
general business and economic conditions, and other matters, many of which are
beyond the control of Security or M&I. Analyses based upon forecasts of future
results are not necessarily indicative of actual values, which may be
significantly more or less favorable than suggested by such analyses. No
company or transaction used as a comparison in the analyses is identical to
Security or M&I or to the Merger. Accordingly, an analysis of the results of
the foregoing necessarily involves complex considerations and judgments
concerning financial and operating characteristics of the companies and other
factors that could affect the public trading volume of the companies to which
Security, M&I and the Merger are being compared. Additionally, any estimates
included in Baird's analyses do not purport to be appraisals and are not
necessarily reflective of the prices at which businesses actually may be sold.
Because such estimates are inherently subject to uncertainty, Baird does not
assume responsibility for their accuracy.
 
  Baird, as part of its investment banking business, is engaged in the
evaluation of businesses and their securities in connection with mergers and
acquisitions, negotiated underwritings, competitive biddings, secondary
distributions of listed and unlisted securities, private placements, and
valuations for estate, corporate and other purposes. Security retained Baird
because of its experience and expertise in the valuation of businesses and
their securities in connection with mergers and acquisitions. In the ordinary
course of business, Baird may from time to time trade equity securities of
Security and M&I for its own account and for accounts of its customers and,
accordingly, may at any time hold a long or short position in such securities.
In addition, Northwestern Mutual Life Insurance Company, the parent company of
Baird, beneficially owns approximately 8.97% of the outstanding shares of M&I
Common Stock.
 
  Compensation. Pursuant to an engagement letter dated February 7, 1997
between Security and Baird, Baird has earned a retainer fee of $25,000 and a
fee of $100,000 for the rendering of its written opinion dated March 14, 1997.
In addition, Baird will receive a fee equal to one-half of one percent of the
value of the total consideration payable in the Merger (including the value of
option shares). Security has also agreed to reimburse Baird for its expenses
of legal counsel. Security has also agreed to indemnify Baird, its affiliates
and their respective directors, officers, employees, agents and controlling
persons against certain liabilities relating to or arising out of its
engagement, including liabilities under the federal securities laws. Baird has
provided certain investment banking and advisory services to Security and M&I
from time to time, for which it has received customary compensation, including
acting as managing underwriter of the initial public offering of Security
Common Stock in 1993, acting as co-manager of public offerings of subordinated
notes of M&I in 1993 and 1995 and acting as co-manager in the public offering
of M&I Capital Trust A 7.65% Capital Securities in 1996.
 
 
                                      26
<PAGE>
 
MERGER CONSIDERATION
 
  The Merger Agreement provides that, at the Effective Time and subject to the
election and allocation procedures provided for therein, each share of Security
Common Stock issued and outstanding immediately prior to the Effective Time
will cease to be outstanding and will be converted into, and become the right
to receive, either: (i) approximately $41.40 in cash and approximately 1.3561
shares of M&I Common Stock as described below (the "Mixed Consideration"); (ii)
subject to the allocation procedures applicable to oversubscriptions for
elections to receive M&I Common Stock, a number of shares of M&I Common Stock
determined as described below (the "Stock Consideration"); or (iii) subject to
the allocation procedures applicable to oversubscriptions for elections to
receive cash, an amount in cash (without interest) determined as described
below (the "Cash Consideration").
 
  The actual Stock Consideration and Cash Consideration will be determined
based on a formula, set forth in the Merger Agreement, which takes into
consideration: (i) the Valuation Period Market Value as reported on the Nasdaq
National Market during the ten (10) consecutive trading-day period during which
the shares of M&I Common Stock are traded on the Nasdaq National Market ending
on the fifth calendar day immediately prior to the Effective Time (the
"Valuation Period"); and (ii) the total number of shares of Security Common
Stock issued and outstanding on the last day of the Valuation Period (the
"Valuation Period Share Number"). A table is provided on page 13 and on
Appendix B of this Proxy Statement-Prospectus which sets forth the amount of
cash and M&I Common Stock to be issued in the Merger and the actual number of
shares of M&I Common Stock to be issued in the Merger per share of Security
Common Stock based upon various assumed Valuation Period Market Values and an
assumed Valuation Period Share Number.
 
  Based on the closing price reported on the Nasdaq National Market of M&I
Common Stock on March 14, 1997 of $37.3125 per share, (i) a holder of Security
Common Stock electing to receive Mixed Consideration would receive
approximately $41.40 in cash and approximately 1.3561 shares of M&I Common
Stock for a total value of $92 per share, (ii) a holder of Security Common
Stock electing to receive Stock Consideration would receive approximately
2.4657 shares of M&I Common Stock per share of Security Common Stock for a
value of $92 per share, and (iii) a holder of Security Common Stock electing to
receive Cash Consideration would receive $92 per share of Security Common
Stock.
 
  The Merger Agreement may be terminated by Security on the day preceding the
anticipated Effective Time if: (a) the average of the daily closing price of a
share of M&I Common Stock as reported on the Nasdaq National Market during the
period of ten (10) trading days ending at the close of the third trading day
immediately preceding the Effective Time (the "Company Average Price") is less
than $30.875; and (b) the number obtained by dividing the Company Average Price
by the average closing price of M&I Common Stock as reported on the Nasdaq
National Market for the ten (10) trading days immediately preceding March 15,
1997 is less than the number obtained by dividing the Final Index Price (as
defined below) by the Initial Index Price (as defined below) and subtracting
 .15 from such quotient. The "Final Index Price" means the average of the "Final
Prices" of a selected group of bank stocks as identified on Exhibit 9.1 to the
Merger Agreement attached as Appendix A to this Proxy Statement-Prospectus (the
"Index Group"), where the "Final Price" of any such company means the average
of the daily closing sale prices of a share of such common stock of such
company as reported in the consolidated transaction reporting system for the
market or exchange on which such common stock is principally traded during the
period of ten (10) trading days ending at the close of the third trading day
immediately preceding the Effective Time. The "Initial Index Price" means a
weighted average of the per share closing prices of the common stock of the
companies comprising the Index Group as reported in the consolidated
transaction reporting system for the market or exchange on which such common
stock is principally traded for the ten (10) trading days immediately preceding
March 15, 1997.
 
  Security's termination rights described above are subject to M&I's right to
extinguish such termination election by agreeing to adjust upward the
consideration payable to holders of Security Common Stock so that the
conditions set forth in either (a) or (b), above, shall be deemed not to exist.
The condition set forth in (a),
 
                                       27
<PAGE>
 
above, shall be deemed not to exist if the Stock Amount is increased so that
the Stock Amount (as increased) multiplied by the Valuation Period Market
Value is not less than $375,971,980. The condition set forth in (b), above,
shall be deemed not to exist if the Stock Amount is increased in an amount so
that if the Company Average Price (for purposes of (b), above) were equal to
the Company Average Price (as previously calculated) plus the Adjustment
Amount (as defined below), the condition set forth in (b), above, would not
exist. The Adjustment Amount shall equal (x) the product of the Company
Average Price (as previously calculated) and the number of shares by which the
Stock Amount is increased, divided by (y) the Stock Amount (prior to such
increase).
 
  As described below, and subject to the election and allocation procedures
provided for in the Merger Agreement, the value of the Stock Consideration to
be received for each share of Security Common Stock being converted into M&I
Common Stock (basing the value of the Stock Consideration on the Valuation
Period Market Value) and the Cash Consideration to be received for each share
of Security Common Stock being converted into cash will be equal and will be
calculated as follows:
 
  (i) Stock Consideration will equal a number of shares of M&I Common Stock
      equal to the "Average Per Share Consideration" divided by the Valuation
      Period Market Value, where the "Average Per Share Consideration" means
      the quotient of (a) the sum of $376,335,605 plus the product of
      12,327,390 and the Valuation Period Market Value, divided by (b) the
      Valuation Period Share Number.
 
  (ii) Cash Consideration will equal cash equal to the Average Per Share
       Consideration.
 
  Under the Merger Agreement, the aggregate number of shares of M&I Common
Stock to be issued in the Merger (the "Stock Amount") is equal to 12,327,390.
Under the Merger Agreement, the aggregate cash payable by M&I to holders of
Security Common Stock pursuant to the Merger is equal to $376,335,605
regardless of the Valuation Period Market Value and will vary only according
to the total number of shares of Security Common Stock outstanding as of the
Effective Time. The total consideration to be received by holders of Security
Common Stock could vary, therefore, if the number of shares of Security Common
Stock outstanding at the end of the Valuation Period and at the Effective Time
differs from 9,090,232. This is not expected to happen, however, since under
the terms of the Merger Agreement (i) Security is prohibited from issuing any
shares of its Common Stock except pursuant to existing stock options, and (ii)
Security has agreed, to the extent permitted by law, to repurchase shares of
its Common Stock equal to the number of shares issued pursuant to stock
options.
 
  BECAUSE THE AGGREGATE NUMBER OF SHARES OF M&I COMMON STOCK AND THE AGGREGATE
AMOUNT OF CASH TO BE EXCHANGED IN THE MERGER WILL BE FIXED UNDER THE ELECTION
AND ALLOCATION PROCEDURES DESCRIBED HEREIN, NO ASSURANCE CAN BE GIVEN THAT AN
ELECTION BY ANY GIVEN HOLDER OF SECURITY COMMON STOCK WILL BE HONORED WITH
RESPECT TO ANY OR ALL SHARES OF SECURITY COMMON STOCK HELD BY SUCH HOLDER.
THUS, HOLDERS MAY NOT RECEIVE THEIR REQUESTED FORM OF CONSIDERATION. SEE "THE
MERGER--ELECTION PROCEDURES."
 
  Under the Merger Agreement, if between the date of the Merger Agreement and
the Effective Time, either Security or M&I declares a stock dividend or
distribution upon or subdivides, splits up, reclassifies or combines its
Common Stock, or declares a dividend or makes a distribution on its Common
Stock in any security convertible into its Common Stock, appropriate
adjustment or adjustments will be made to the Per Share Stock Consideration
(as defined below), per share Cash Consideration and the Stock Amount.
 
  ALTHOUGH THE STOCK CONSIDERATION WILL BE BASED ON THE AVERAGE MARKET PRICE
OF M&I COMMON STOCK DURING THE VALUATION PERIOD (I.E., THE VALUATION PERIOD
MARKET VALUE), THE MARKET PRICE OF M&I COMMON STOCK MAY FLUCTUATE AND, ON THE
DATE OF RECEIPT OF SHARES OF M&I COMMON STOCK BY HOLDERS OF SECURITY COMMON
STOCK, MAY BE MORE OR LESS THAN THE FINAL M&I STOCK PRICE. HOLDERS OF SECURITY
COMMON STOCK ARE URGED TO OBTAIN CURRENT MARKET
 
                                      28
<PAGE>
 
QUOTATIONS FOR M&I COMMON STOCK AND SECURITY COMMON STOCK IN CONNECTION WITH
VOTING THEIR SHARES AND MAKING ELECTIONS TO RECEIVE THE MIXED CONSIDERATION,
STOCK CONSIDERATION OR CASH CONSIDERATION.
 
  No fractional shares of M&I Common Stock will be issued in the Merger.
Instead, M&I will pay to each holder of Security Common Stock who would
otherwise be entitled to a fractional share an amount of cash equal to the
fraction of a share of M&I Common Stock to which the holder of Security Common
Stock would otherwise be entitled multiplied by the average of the final bid
and asked price for a share of M&I Common Stock as reported on the Nasdaq
National Market on the five (5) business days immediately preceding the
Effective Time.
 
  The terms of the Merger were determined by M&I & Security on the basis of
arm's-length negotiations. The pricing formula applicable to Security Common
Stock was determined on the basis of arm's-length negotiations.
 
ELECTION PROCEDURES
 
  At least thirty days prior to the Effective Date (the "Mailing Date"), a
bank or trust company that will be designated by M&I and Security (the
"Exchange Agent") will send election forms (an "Election Form") and other
appropriate and customary transmittal materials to each holder of record of
Security Common Stock as of five business days prior to the Mailing Date. Each
election form will allow the holder either (i) to elect to receive
approximately $41.40 in cash and approximately 1.3561 shares of M&I Common
Stock in exchange for each share of such holder's Security Common Stock
("Mixed Election"); (ii) to elect to receive only shares of M&I Common Stock
in exchange for each share of such holder's Security Common Stock ("Stock
Election"); (iii) to elect to receive only cash in exchange for each share of
such holder's Security Common Stock (the "Cash Election"); or (iv) to make no
election ("No Election Shares"). If a holder of Security Common Stock does not
submit to the Exchange Agent a properly completed election form prior to 5:00
p.m., New York City time, on the 25th day following the Mailing Date (the
"Election Deadline"), such holder's shares of Security Common Stock will be
treated by the Exchange Agent as No Election Shares.
 
  A FIXED NUMBER OF SHARES OF M&I COMMON STOCK WILL BE ISSUED AND A FIXED
AMOUNT OF CASH PAID IN THE MERGER. ACCORDINGLY, THERE IS NO ASSURANCE THAT A
HOLDER OF SECURITY COMMON STOCK WILL RECEIVE THE FORM OF CONSIDERATION THAT
SUCH HOLDER ELECTS WITH RESPECT TO ANY OR ALL SHARES OF SECURITY COMMON STOCK
HELD BY SUCH HOLDER UNLESS SUCH HOLDER ELECTS MIXED CONSIDERATION. IF THE
ELECTIONS RESULT IN AN OVERSUBSCRIPTION IN RESPECT TO SHARES OF SECURITY
COMMON STOCK WHICH WOULD OTHERWISE RECEIVE EITHER THE STOCK CONSIDERATION OR
THE CASH CONSIDERATION, THE PROCEDURES FOR ALLOCATING M&I COMMON STOCK AND
CASH, DESCRIBED BELOW UNDER "--ALLOCATION," WILL BE FOLLOWED BY THE EXCHANGE
AGENT.
 
  TO MAKE AN ELECTION, A HOLDER OF SECURITY COMMON STOCK MUST SUBMIT A
PROPERLY COMPLETED ELECTION FORM SO THAT IT IS ACTUALLY RECEIVED BY THE
EXCHANGE AGENT AT OR PRIOR TO THE ELECTION DEADLINE IN ACCORDANCE WITH THE
INSTRUCTIONS ON THE ELECTION FORM. AN ELECTION FORM WILL BE PROPERLY COMPLETED
ONLY IF ACCOMPANIED BY CERTIFICATES REPRESENTING ALL SHARES OF SECURITY COMMON
STOCK COVERED THEREBY.
 
  A holder of Security Common Stock may revoke or change an Election Form that
has been submitted to the Exchange Agent, but to be effective, such notice
must actually be received by the Exchange Agent at or prior to the Election
Deadline. In the event of a revocation of an Election Form, the Exchange Agent
will, upon receiving a written request from the holder of Security Common
Stock making such revocation, return the certificates of Security Common Stock
submitted by such holder, and such holder shall be deemed as having
 
                                      29
<PAGE>
 
made no election. The Exchange Agent will have reasonable discretion to
determine whether any election, revocation or change has been properly or
timely made, and any good faith decisions of the Exchange Agent shall be
binding and conclusive.
 
  M&I will make available one or more Election Forms as may be reasonably
requested by all persons who become holders (or beneficial owners) of Security
Common Stock between a date as of five business days prior to the Mailing Date
and the close of business on the business day prior to the Election Deadline.
 
  Because the Election Deadline will occur prior to the end of the Valuation
Period, the Valuation Period Market Value will not be determined by the time
holders of Security Common Stock will be required to submit their Election
Forms.
 
  In addition, in the event that Security elects to terminate the Merger
Agreement and M&I does not elect to extinguish the election by agreeing to
adjust upward the consideration payable to holders of Security Common Stock,
the Exchange Agent will promptly return stock certificates representing shares
of Security Common Stock submitted with the Election Forms. The Exchange Agent
and M&I will use their commercially reasonable efforts to cooperate with
Security and holders of Security Common Stock to facilitate return of
certificates representing shares of Security Common Stock in the event of such
termination, but return other than by registered mail will only be made at the
expense, written direction and risk of holders of Security Common Stock,
accompanied by a pre-paid, pre-addressed return courier envelope sent to the
Exchange Agent.
 
ALLOCATION
 
  Within five business days after the Election Deadline, unless the Effective
Time has not yet occurred, in which case as soon as practicable thereafter, M&I
will cause the Exchange Agent to effect the allocation among the holders of
Security Common Stock of rights to receive M&I Common Stock and/or cash in the
Merger in accordance with the Election Forms as discussed below.
 
    (a) Each of the Mixed Election shares shall be converted into a right to
  receive approximately $41.40 in cash and approximately 1.3561 shares of M&I
  Common Stock.
 
    (b) If the number of shares of M&I Common Stock that would be issued upon
  conversion in the Merger of the Mixed Election shares and the Stock
  Election shares is less than the Stock Amount, then:
 
      (i) each of the Stock Election shares shall be converted into the
    right to receive a number of shares of M&I Common Stock equal to the
    "Per Share Stock Consideration," where the Per Share Stock
    Consideration means the Average Per Share Consideration divided by the
    Valuation Period Market Value;
 
      (ii) the Exchange Agent will select first from among the holders of
    No Election shares and then (if necessary) from among the Cash Election
    shares, a sufficient number of shares ("Stock Designated Shares"), by a
    pro rata selection process, such that the number of shares of M&I
    Common Stock that will be issued in the Merger equals as closely as
    practicable the Stock Amount, and each of the Stock Designated Shares
    will be converted into the right to receive a number of shares of M&I
    Common Stock equal to the Per Share Stock Consideration; and
 
      (iii) each of the No Election shares and the Cash Election shares
    which are not Stock Designated Shares will be converted into the right
    to receive cash equal to the Average Per Share Consideration.
 
    (c) If the number of shares of M&I Common Stock that would be issued in
  the Merger upon conversion of the Mixed Election shares and the Stock
  Election shares is greater than the Stock Amount, then:
 
      (i) each of the Cash Election shares and No Election shares will be
    converted into the right to receive cash equal to the Average Per Share
    Consideration;
 
      (ii) the Exchange Agent will select from among the Stock Election
    shares by a pro rata selection process a sufficient number of shares
    ("Cash Designated Shares") such that the number of shares of
 
                                       30
<PAGE>
 
    M&I Common Stock that will be issued in the Merger equals as closely as
    practicable the Stock Amount, and each of the Cash Designated Shares
    will be converted into the right to receive cash equal to the Average
    Per Share Consideration; and
 
      (iii) each of the Stock Election shares that are not Cash Designated
    Shares will be converted into the right to receive a number of shares of
    M&I Common Stock equal to the Per Share Stock Consideration.
 
  The pro rata process to be used by the Exchange Agent will consist of such
equitable pro rata processes as will be mutually determined by M&I and
Security, and as will be further described in the election forms. In the pro
rata process, Security shall have the right to cause the Exchange Agent to
allocate Stock Election shares to holders of Security Common Stock who have not
exercised stock options at the request of Security.
 
  BECAUSE THE FEDERAL INCOME TAX CONSEQUENCES OF RECEIVING CASH, M&I COMMON
STOCK, OR BOTH CASH AND M&I COMMON STOCK WILL DIFFER, SECURITY COMMON
SHAREHOLDERS ARE URGED TO READ CAREFULLY THE INFORMATION SET FORTH UNDER THE
CAPTION "--CERTAIN FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER." IN ADDITION,
BECAUSE THE STOCK CONSIDERATION AND THE MIXED CONSIDERATION CAN FLUCTUATE IN
VALUE FROM THE DETERMINATION MADE DURING THE VALUATION PERIOD, THE ECONOMIC
VALUE PER SHARE RECEIVED BY SECURITY COMMON SHAREHOLDERS WHO RECEIVE THE STOCK
CONSIDERATION OR THE MIXED CONSIDERATION MAY, AS OF THE DATE OF RECEIPT BY
THEM, BE MORE OR LESS THAN THE AMOUNT OF CASH CONSIDERATION PER SHARE RECEIVED
BY SECURITY COMMON SHAREHOLDERS WHO RECEIVE CASH CONSIDERATION.
 
  The failure to timely submit a properly completed Election Form will result
in a holder of Security Common Stock having no choice as to the receipt of M&I
Common Stock or cash in the Merger. See "--Election Procedures."
 
EFFECTIVE TIME
 
  Security and M&I will cause the Merger to be consummated by filing Articles
of Merger with the Department of Financial Institutions of the State of
Wisconsin or such later time as specified in the Articles. The filing with
respect to the Merger will occur as promptly as practicable after the
satisfaction or, if permissible, waiver of the remaining conditions to M&I's
and Security's obligations to effect the Merger, but in no event prior to the
earlier of (i) as soon as practicable following the completion of the
conversion of Security's bank offices to M&I's data processing systems,
including any and all testing relating to such conversion, or (ii) October 1,
1997. The parties currently anticipate that the Merger will be completed on or
about October 1, 1997, subject to receipt of shareholder and regulatory
approvals.
 
CONVERSION OF SHARES; PROCEDURES FOR EXCHANGE OF CERTIFICATES; DIVIDENDS
 
  Conversion of Shares. The conversion of Security Common Stock into M&I Common
Stock, the right to receive cash or the right to receive M&I Common Stock and
cash will occur automatically at the Effective Time.
 
  Procedures for Exchange of Certificates. Election Forms and Letter of
Transmittal forms with respect to Security Common Stock will be distributed to
each holder of Security Common Stock who is a holder of record on the date
which is five business days prior to the Mailing Date. Such Transmittal and
Election Forms will contain instructions with respect to the surrender of
certificates representing Security Common Stock to be exchanged for M&I Common
Stock, cash or M&I Common Stock and cash. See "--Election Procedures."
 
  As soon as practicable after the Effective Time, the Exchange Agent will send
a transmittal form to each former holder of Security Common Stock who has not
yet returned the Election Forms and share certificates.
 
  Neither M&I nor the Exchange Agent will be liable to any former shareholder
of Security for any amount properly delivered to a public official pursuant to
applicable abandoned property, escheat or similar laws.
 
                                       31
<PAGE>
 
  HOLDERS OF SECURITY COMMON STOCK SHOULD NOT FORWARD SECURITY COMMON STOCK
CERTIFICATES TO THE EXCHANGE AGENT UNTIL THEY HAVE RECEIVED AN ELECTION FORM.
HOLDERS OF SECURITY COMMON STOCK SHOULD NOT RETURN COMMON STOCK CERTIFICATES
WITH THE ENCLOSED PROXY.
 
  Dividends. No dividends or other distributions declared or made after the
Effective Time with respect to M&I Common Stock with a record date after the
Effective Time will be paid to the holder of any unsurrendered certificate
representing Security Common Stock with respect to the shares of M&I Common
Stock represented thereby, and no cash payment in lieu of fractional shares
will be paid to any such holder, until the holder of record of such
certificate surrenders the certificate. Subject to the effect of applicable
laws, following surrender of any certificate, there will be paid to the holder
of the certificates representing whole shares of M&I Common Stock issued in
exchange, without interest, (i) promptly, the amount of any cash payable in
lieu of a fractional share of M&I Common Stock and the amount of dividends or
other distributions with record and payment dates after the Effective Time and
before the date of such surrender with respect to whole shares of M&I Common
Stock; and (ii) 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
the whole shares of M&I Common Stock. In no event shall the persons entitled
to receive such dividends, distributions and cash in lieu of fractional shares
be entitled to receive interest on the amounts payable.
 
REPRESENTATIONS AND WARRANTIES
 
  The Merger Agreement contains certain customary representations and
warranties of each of M&I and Security (and in certain cases also relating to
their respective subsidiaries) including, but not limited to:
(a) organization, regulatory registrations or authorizations and similar
corporate matters; (b) capital structures; (c) authorization, execution,
delivery, performance and enforceability of the Merger Agreement and other
related matters; (d) compliance with laws; (e) documents filed with the
Commission, the Federal Reserve Board and other applicable securities or
banking authorities and the accuracy of information contained therein; (f) no
material pending or threatened litigation or governmental investigations or
agreements except as otherwise disclosed in filings with the Commission; (g)
retirement and other employee plans and matters relating to the Employee
Retirement Income Security Act of 1974, as amended ("ERISA"), and, with
respect to Security, certain matters relating to employment contracts, options
and similar matters; (h) the accuracy of information supplied by each of M&I
and Security in connection with the Registration Statement and this Proxy
Statement-Prospectus; (i) good title to properties, free of liens; (j) with
respect to Security only, the absence of certain environmental matters; (k)
the absence of any burdensome contracts, agreements or restrictions; (l)
certain tax matters; (m) with respect to Security only, certain insurance
matters; (n) absence of certain material changes or events since December 31,
1996, including changes or events relating to the incurrence of a material
adverse effect in the business, operations, properties (including intangible
properties), condition (financial or otherwise), assets or liabilities
(including contingent liabilities) of M&I and its subsidiaries, taken as a
whole, or of Security and its subsidiaries, taken as a whole; (o) material
contracts; (p) full disclosure with regard to all written information
furnished pursuant to the Merger Agreement; (q) the opinion of financial
advisor; and (r) with respect to Security only, the shareholder vote required
to approve the Merger Agreement.
 
  The Merger Agreement also contains additional representations and warranties
by Security to M&I that the Board of Directors of Security has taken all
actions necessary to ensure that the restrictions of Sections 180.1130-32,
180.1134, 180.1140-44 and 180.1150 of the Wisconsin Business Corporation Law
(the "WBCL") (relating to business combinations with interested shareholders
and other potential restrictions on M&I's ability to consummate the Merger,
generally discussed under "DESCRIPTION OF M&I CAPITAL STOCK--Certain
Provisions of the Wisconsin Business Corporation Law") do not apply to the
Merger.
 
  The representations and warranties of M&I and Security contained in the
Merger Agreement are qualified by materiality standards contained in the
Merger Agreement or by the disclosure schedules of M&I and Security delivered
pursuant to the Merger Agreement.
 
 
                                      32
<PAGE>
 
CONDITIONS TO THE MERGER
 
  The Merger Agreement contains certain conditions to the obligations of M&I
and Security to consummate the Merger. In addition to other customary closing
conditions, the following conditions are contained in the Merger Agreement:
(a) the Merger shall have been approved by a majority of the holders of
Security Common Stock; (b) the Registration Statement shall have been declared
effective by the Commission under the Securities Act (and no stop order
suspending the effectiveness of the Registration Statement shall have been
issued) and M&I shall also have received all other federal and state
securities permits and authorizations necessary to issue M&I Common Stock
pursuant to the Merger Agreement; (c) the Merger shall have been approved by
the Federal Reserve Board and DFI without the imposition of any condition that
is materially burdensome to M&I and all conditions required to be satisfied
prior to the Effective Time imposed by such approval shall have been satisfied
and all waiting periods relating to such approval shall have expired; (d)
there shall not be any injunction or restraining order or regulatory
impediment preventing the consummation of the Merger; (e) there shall not be
any pending material action, proceeding or investigation (i) challenging or
seeking material damages in connection with the Merger or (ii) seeking to
limit the exercise of ownership rights by M&I of the business or assets of
Security which in either case is reasonably likely to have a Material Adverse
Effect on Security or M&I; (f) M&I's and Security's representations and
warranties contained in the Merger Agreement shall be true and correct unless
the failure to be true and correct would have a Material Adverse Effect on
Security; (g) all agreements and covenants of each of M&I and Security
required to be performed by it under the Merger Agreement shall have been
performed by it in all material respects; (h) all consents, approvals,
authorizations or orders required to be obtained in connection with the Merger
by either M&I or Security shall have been obtained by it; and (i) the opinions
of Godfrey & Kahn, S.C. and Skadden, Arps, Slate, Meagher & Flom LLP that the
Merger will be treated for federal income tax purposes as a "reorganization"
within the meaning of Section 368(a) of the Code shall be rendered
substantially as described in the Merger Agreement.
 
  In addition to the mutual conditions discussed above, M&I's obligation to
consummate the Merger is subject to the following additional conditions: (a)
that M&I shall have received from KPMG Peat Marwick LLP a "comfort letter"
with respect to Security's financial statements included or incorporated by
reference in this Proxy Statement-Prospectus; and (b) that no governmental
entity shall have taken any action, and no statute, rule or order shall have
been enacted, entered, enforced or deemed applicable to the Merger by any
governmental entity, which would be likely to have a Material Adverse Effect
on Security or M&I, taken as a whole.
 
  In addition to the mutual conditions discussed above, Security's obligation
to consummate the Merger is subject to the condition that the shares of M&I
Common Stock to be issued in the Merger shall have been approved for listing,
upon notice of issuance, on the Nasdaq National Market.
 
  The parties currently anticipate that the Merger will be completed on or
about October 1, 1997, subject to receipt of shareholder and regulatory
approvals. M&I has agreed to irrevocably waive certain of the conditions to
its obligation to consummate the Merger in advance of the Effective Date in
connection with Security's agreement to mail certain branch closing notices.
These conditions are: (a) the breach by Security of any of its representations
and warranties contained in the Merger Agreement; (b) the breach by Security
of its agreements and covenants contained in the Merger Agreement from the
date of the Merger Agreement to the date that M&I gives its waiver (the
"Waiver Date"); (c) the breach by Security of its covenants and agreements
contained in Section 4.1(a) through 4.1(e) of the Merger Agreement from the
Waiver Date through the consummation of the Merger, except where such breach
results in a Material Adverse Effect on Security or is the result of willful
action on the part of Security; (d) the receipt of all consents, approvals,
authorizations or orders required to be obtained in connection with the Merger
(except shareholder and regulatory approvals); (e) the occurrence of any event
which would have a Material Adverse Effect on Security. In addition, (a) M&I
has waived the right to receive a "comfort letter" with respect to Security's
financial statements, and (b) the condition that Godfrey & Kahn, S.C. issue an
opinion, which is subject to certain assumptions, to the effect that the
Merger will be treated for federal income tax purposes as a "reorganization"
within the meaning of Section 368(a) of the Code, will be fulfilled by M&I
receiving such an opinion on the Waiver Date.
 
 
                                      33
<PAGE>
 
TERMINATION; AMENDMENT AND WAIVER
 
  Termination. The Merger Agreement may be terminated at any time prior to the
Effective Time, whether before or after approval of the matters presented in
connection with the Merger by the holders of Security Common Stock at the
Special Meeting: (a) by mutual consent of M&I and Security by a vote of a
majority of the members of the entire Board of Directors; (b) by either M&I or
Security (i) if there has been a breach in any material respect (except when
any statement in a representation or warranty expressly includes a standard of
materiality, such statement shall have been breached in any respect) of any
representation, warranty, covenant or agreement set forth in the Merger
Agreement on the part of M&I or Security, respectively, or (ii) if any
representation or warranty of M&I or Security, respectively, shall be
discovered to have become untrue in any material respect (except when any
statement in a representation or warranty expressly includes a standard of
materiality, such statement shall have been breached in any respect), in
either case which breach or other condition has not been cured within 30
business days following receipt by the nonterminating party of notice of such
breach or other condition or which breach by its nature, cannot be cured prior
to closing and would cause such party to fail to meet its conditions to the
Merger (provided that the Merger Agreement may not be terminated by the
breaching party or party making any representation or warranty which shall
have become untrue in any material respect); (c) by either M&I or Security if
any permanent injunction preventing the consummation of the Merger shall have
become final and nonappealable; (d) by either M&I or Security if the Merger
shall not have been consummated on or prior to December 31, 1997, for a reason
other than the failure of the terminating party to comply with its obligations
under the Merger Agreement; provided that if the Merger shall not have been
consummated by December 31, 1997, as a result of proceedings of a governmental
authority or litigation, then the date on which either M&I or Security may
terminate the Merger Agreement shall be extended to the earlier of (i) the
lapse of a reasonable period of time necessary to consummate the Merger
following the final termination of proceedings of a governmental authority or
litigation or (ii) April 30, 1998; or (e) by either M&I or Security if the
Federal Reserve Board has denied approval of the Merger, and neither M&I nor
Security has, within 30 days after the entry of such order denying approval,
filed a petition seeking review of such order as provided by applicable law.
 
  The Merger Agreement may also be terminated by Security if both of the
following conditions exist on the day preceding the anticipated Effective
Time: (a) the Company Average Price is less than $30.875 and (b) the number
obtained by dividing the Company Average Price by $30.875 has declined by more
than 15% relative to the decline in the market prices of a select group of
bank stocks during the same period. The selected group of bank stocks is
identified on Exhibit 9.1 to the Merger Agreement attached as Appendix A to
this Proxy Statement-Prospectus.
 
  In the event of termination of the Merger Agreement by either M&I or
Security, the Merger Agreement will become void and there will be no liability
or obligation on the part of M&I or Security other than, (i) under certain
specified provisions of the Merger Agreement dealing with confidential
treatment of non-public information and expenses, and other than any
liabilities incurred or suffered by a party as a result of a willful breach of
the Merger Agreement, and (ii) under certain circumstances with regard to the
Termination Fee. See "THE MERGER--Termination Fee."
 
  Amendment and Waiver. Subject to applicable law, (i) the Merger Agreement
may be amended at any time prior to the Effective Time by action taken or
authorized by the respective Boards of Directors of M&I and Security (except
that after the Merger Agreement is approved by the shareholders of Security,
no amendment may be made which would reduce the amount or change the type of
consideration into which each share of Security Common Stock will be converted
pursuant to the terms of the Merger Agreement at the Effective Time) and (ii)
at any time prior to the Effective Time, the parties may extend the time for
performance of the obligations of the other parties to the Merger Agreement,
and waive any inaccuracies in the representations and warranties contained in
the Merger Agreement or any document delivered pursuant thereto or may waive
compliance with any agreements or conditions for their respective benefit
contained in the Merger Agreement.
 
 
                                      34
<PAGE>
 
TERMINATION FEE
 
  As a condition and inducement to M&I's willingness to enter into and perform
its obligations under the Merger Agreement, unless a "Nullifying Event" (as
defined below) shall have occurred, Security has agreed to pay to M&I a fee of
$30 million if the Merger Agreement is terminated in connection with certain
events. The Termination Fee would generally become payable if (i) the Merger
Agreement is terminated (regardless of whether such termination is by M&I or
Security), (ii) prior to or concurrently with such termination a "Trigger
Event" (as defined below) shall have occurred and (iii) prior to, concurrently
with or within 18 months after such termination an "Acquisition Event" (as
defined below) shall have occurred.
 
  In addition, in the event that (i) the Merger Agreement is terminated
(regardless of whether such termination is by M&I or Security) and (ii) a
Trigger Event has occurred, Security is required to pay to M&I its reasonable
out-of-pocket expenses related to the transactions contemplated in the Merger
Agreement, not to exceed $2,500,000.
 
  The Merger Agreement defines the term "Trigger Event" to mean the occurrence
of any of the following events:
 
    (i) Security's Board of Directors shall have failed to approve or
  recommend the Merger Agreement or the Merger or shall have withdrawn or
  modified in a manner adverse to M&I its approval or recommendation of the
  Merger Agreement or the Merger, or shall refuse to reaffirm its approval or
  recommendation upon M&I's reasonable request, or shall have resolved or
  publicly announced an intention to do any of the foregoing;
 
    (ii) Security or any Significant Subsidiary (as such term is defined in
  the Merger Agreement), or the Board of Directors of Security or a
  Significant Subsidiary, shall have recommended to the shareholders of
  Security any "Acquisition Proposal" (as defined below) or shall have
  entered into an agreement with respect to, or authorized, approved,
  proposed or publicly announced its intention to enter into, any Acquisition
  Proposal;
 
    (iii) the Merger Agreement or the Merger shall not have been approved at
  the Special Meeting prior to termination of the Merger Agreement in
  accordance with its terms, if prior to such termination it shall have been
  publicly announced that any person shall have made, or disclosed an
  intention to make, an Acquisition Proposal;
 
    (iv) any person (together with its affiliates and associates) or group
  shall have acquired beneficial ownership or the right to acquire beneficial
  ownership of 20% or more of the then outstanding shares of the stock then
  entitled to vote generally in the election of directors of Security or any
  Significant Subsidiary; or
 
    (v) following the making of an Acquisition Proposal, Security shall have
  willfully breached any covenant or agreement contained in the Merger
  Agreement such that M&I would be entitled to terminate the Merger Agreement
  pursuant to Section 9.1(a)(ii) of the Merger Agreement (without regard to
  any grace period provided for therein), unless such breach is promptly
  cured without jeopardizing consummation of the Merger pursuant to the terms
  of the Merger Agreement.
 
  The Merger Agreement defines the term "Acquisition Proposal" to mean any (i)
publicly announced proposal, (ii) regulatory application or notice, (iii)
agreement or understanding, (iv) disclosure of an intention to make a proposal
or (v) amendment to any of the foregoing, made or filed on or after March 14,
1997, in each case with respect to any of the following transactions with a
counterparty other than M&I: (A) a merger or consolidation, or any similar
transaction, involving Security or any Significant Subsidiary (other than
mergers, consolidations or any similar transactions involving solely Security
and/or one or more wholly owned subsidiaries of Security and other than a
merger or consolidation as to which the common shareholders of Security
immediately prior thereto in the aggregate own at least 70% of the common
stock of the publicly held surviving or successor corporation (or any publicly
held or ultimate parent company thereof) immediately following consummation
thereof); (B) a purchase, lease or other acquisition of all or substantially
all of the assets or deposits of Security or any Significant Subsidiaries; or
(C) a purchase or other acquisition (including by way of merger,
consolidation, share exchange or otherwise) of securities representing 20% or
more of the voting power of Security or any Significant Subsidiary.
 
                                      35
<PAGE>
 
  The Merger Agreement defines "Acquisition Event" to mean the consummation of
any event described in clauses (A), (B) or (C) of the definition of
Acquisition Proposal, except that the percentage referenced in clause (C)
above shall be 50% instead of 20%.
 
  The Merger Agreement defines the term "Nullifying Event" to mean any of the
following events occurring and continuing at a time when Security is not in
material breach of any of its covenants or agreements contained in the Merger
Agreement: (i) M&I is in breach of any of its covenants or agreements
contained in the Merger Agreement such that Security is entitled to terminate
the Merger Agreement pursuant to Section 9.1(iii) of the Merger Agreement
(without regard to any grace period provided for therein), or (ii) the Board
of Directors of M&I shall have failed to approve or recommend the Merger or
shall have withdrawn, modified or changed in any manner adverse to Security
its approval or recommendation of the Merger Agreement or shall have resolved
or publicly announced its intention to do any of the foregoing.
 
CONDUCT OF BUSINESS PENDING MERGER
 
  The Merger Agreement contains certain affirmative and negative covenants of
M&I and Security. Pursuant to the Merger Agreement, each party has agreed
promptly to notify the other of any impending or threatened occurrence of an
event or condition which would cause any of its representations or warranties
contained in the Merger Agreement to be untrue or inaccurate or cause either
party to fail to comply with or satisfy any covenant, condition or agreement
to be complied with under the Merger Agreement. In addition, Security has
agreed that prior to the Effective Time, Security and each of its subsidiaries
will (a) operate its business only in the ordinary course consistent with past
practices; (b) use reasonable efforts to preserve intact its business
organization and assets, maintain its rights and franchises, retain the
services of its officers and key employees and maintain its relationships with
customers; (c) use all reasonable efforts to maintain and keep its properties
in good repair and condition ordinary wear and tear excepted; (d) use all
reasonable efforts to keep in full force and effect insurance and bonds
comparable in amount and scope of coverage to that now maintained by it; and
(e) use all reasonable efforts to perform in all material respects all
obligations to be performed by it under all material contracts, leases and
documents relating to or affecting its assets, properties and business.
 
  Security has also agreed that prior to the Effective Time, neither Security
nor any of its subsidiaries will (without the prior written consent of M&I),
except as provided in the Merger Agreement: (a) (i) grant any salary increase
or bonus increase to any employee with an employment contract, except pursuant
to the terms of the contracts or preexisting formulas and subject to certain
additional limitations, (ii) grant any general salary increases to employees
as a class above certain prescribed limitations, (iii) effect any change in
retirement benefits to any class of employees or any officer (unless such
change is contractually required or otherwise required by law) which would
increase retirement benefit liabilities, (iv) adopt, enter into, amend or
modify any employee benefit plan to increase or accelerate obligations of
Security or its subsidiaries thereunder, or (v) enter into or amend any
employment, severance or similar agreements or arrangements with any employee,
director or officer or otherwise change the employee-at-will status of any
current employee; (b) declare or pay any dividend other than (i) regular
quarterly cash dividends on Security Common Stock not in excess of $0.30 per
share (provided that in the quarter that the Effective Time occurs,
shareholders of Security will receive cash dividends only with respect to
shares of Security Common Stock held or with respect to shares of M&I Common
Stock received pursuant to the Merger Agreement, but not both) or (ii)
dividends by a subsidiary of Security to Security; (c) redeem, purchase or
otherwise acquire any shares of Security capital stock; (d) merge with or into
any other corporation or bank or permit any other corporation or bank to merge
into it or consolidate with any other corporation or bank, or effect any
reorganization or recapitalization; (e) other than in the ordinary course of
business and consistent with past practice, (i) purchase or otherwise acquire
any substantial portion of the assets, or more than 5% of the stock, of any
corporation, bank or other business or (ii) liquidate, sell or dispose of, or
encumber any assets or acquire any assets; (f) split, combine, or reclassify
any of its capital stock or issue or authorize or propose the issuance of any
other securities in respect of, in lieu of or in substitution of such capital
stock; (g) issue any shares of Security's capital stock other than (i)
pursuant to outstanding employee
 
                                      36
<PAGE>
 
stock options or (ii) pursuant to Security employee benefit plans; (h) propose
or adopt any amendment to its articles of incorporation or by-laws in any way
adverse to M&I; (i) purchase any shares of M&I Common Stock (except in a
fiduciary capacity for the account of its customers); (j) change any of its
methods of accounting, or methods of reporting income or deductions for
federal income tax purposes, in effect at December 31, 1996; (k) change any
lending, investment, liability management or other material policies
concerning the business or operations of Security or any of its subsidiaries,
including, without limitation, (i) the acquisition or sale of any contracts
for the purchase or sale of financial or other futures or any put or call
options, or enter into any hedges or interest rate swaps relating to cash,
securities, or any commodities whatsoever or enter into any derivative
transaction, (ii) the sale, assignment, transfer, pledge, mortgage or
encumbrance with respect to any of its assets with a value in excess of
$100,000 individually, (iii) the making of any investment with an interest
maturity of five years or more except in the ordinary course of business, (iv)
the incurrence of any material liabilities or material obligations, whether
directly or by way of guaranty, including any obligation for borrowed money,
whether or not evidenced by a note, bond, debenture or similar instrument,
except pursuant to existing credit agreements and other borrowing facilities
filed as exhibits to Security's reports to the Commission and which are in the
ordinary course of business consistent with past practice, or otherwise in an
aggregate amount of $100,000 or less; (l) enter into any agreement with
respect to any acquisition of a material amount of assets or securities or any
discharge, waiver, satisfaction, release or relinquishment of any material
contract rights, liens, encumbrances, debt or claims, not in the ordinary
course of business and consistent with past practices except which together
amount to less than $200,000; (m) settle any claim, action, suit, litigation,
proceeding, arbitration, investigation or controversy of any kind, for any
amount in excess of $250,000, net of any insurance proceeds or in any manner
which would restrict in any material respect the operations or business of
Security or any of its subsidiaries; and (n) take any action or failure to
take any action which individually or in the aggregate can be expected to have
a material adverse effect on Security and its subsidiaries, taken as a whole.
 
  Pursuant to the Merger Agreement, M&I has agreed that prior to the Effective
Time, M&I will (a) maintain its corporate existence in good standing and
maintain all books and records in accordance with generally accepted
accounting principles and practices as utilized in M&I's financial statements
applied on a consistent basis; and (b) conduct its business in a manner that
does not violate any laws. M&I has also agreed that prior to the Effective
Time, neither M&I nor any of the M&I subsidiaries will propose or adopt any
amendments to its Articles of Incorporation or Bylaws in any way adverse to
Security.
 
  M&I has also agreed that prior to the Effective Time, it will not (a)
declare or pay any extraordinary dividend on or make any other extraordinary
or special distribution in respect of its capital stock; (b) take any action
to cause any of its representations or warranties to become untrue in any
material respect; (c) take any action which would disqualify the Merger as a
reorganization under Section 368 of the Code; (d) amend its Articles of
Incorporation or Bylaws in a manner which would adversely affect the terms of
the M&I Common Stock or the ability of M&I to consummate the Merger; and (e)
enter into any agreement providing for any transaction in which the surviving
company of such transaction would be prohibited from consummating the Merger
in accordance with the terms of the Merger Agreement.
 
NO SOLICITATION OF TRANSACTIONS
 
  The Merger Agreement provides that Security will not authorize or permit any
of its officers, directors, employees or agents to directly or indirectly
solicit, initiate or encourage any inquiries relating to, or the making of any
proposal which constitutes, a "takeover proposal" (as defined below), or (i)
recommend or endorse any takeover proposal, (ii) participate in any
discussions or negotiations with respect to a takeover proposal, or
(iii) provide third parties with any nonpublic information relating to any
such inquiry or proposal. Security may, and may authorize and permit its
officers, directors, employees or agents to, provide third parties with
nonpublic information, otherwise facilitate any effort or attempt by any third
party to make or implement a takeover proposal, recommend or endorse any
takeover proposal with or by any third party, and participate in discussions
and negotiations with any third party relating to any takeover proposal, if
the Board of Directors of Security, after having consulted with and considered
the advice of outside counsel, has determined in good faith that such actions
are necessary for the discharge of its fiduciary duties.
 
                                      37
<PAGE>
 
  At the time the Merger Agreement was entered into, Security agreed to cease
and cause to be terminated any existing activities, discussions or
negotiations previously conducted with any parties other than M&I with respect
to any of the foregoing. Security also agreed to take all actions necessary or
advisable to inform its officers, directors, employees or agents of Security's
obligations in this regard. Security has agreed to notify M&I immediately if
any such inquiries or takeover proposals are received by, any such information
is requested from, or any such negotiations or discussions are sought to be
initiated or continued with, Security. The term "takeover proposal" means any
tender or exchange offer, proposal for a merger, consolidation or other
business combination involving Security or any Seller Subsidiary (as defined
in the Merger Agreement) or any proposal or offer to acquire in any manner a
substantial equity interest in, or a substantial portion of the assets of,
Security or any Seller Subsidiary other than the transactions contemplated or
permitted by the Merger Agreement.
 
DATA PROCESSING CONVERSION
 
  The Merger Agreement provides that M&I, at its own expense, shall use its
reasonable efforts to complete the conversion of Security's bank offices to
M&I's data processing systems, including any and all testing related to such
conversion, as soon as practicable after March 14, 1997. M&I and Security
agreed in the Merger Agreement to negotiate in good faith to enter into a data
processing services contract with terms and conditions and costs to Security,
that are no less favorable than Security's current data processing contracts.
Under the Merger Agreement, the Merger cannot be consummated until the earlier
of (i) the completion of the data processing conversion; or (ii) October 1,
1997.
 
MANAGEMENT AND OPERATIONS AFTER THE MERGER
 
  Additional M&I Director. M&I and Security have an understanding that M&I
will appoint one of the current Security directors to the M&I Board of
Directors after the Effective Time. The Security director who will be
appointed to the M&I Board of Directors is expected to be Mr. Robert A.
Schaefer.
 
  M&I Dividend Policy. M&I has no present intention to change its existing
dividend policy in connection with the Merger. Any M&I dividends are subject
to declaration by M&I's Board of Directors and applicable governmental
regulations and policies.
 
INTERESTS OF CERTAIN PERSONS IN THE MERGER
 
  Certain members of Security's management and the Security Board of Directors
may be deemed to have certain interests in the Merger which are in addition to
their interests as shareholders of Security generally. The Security Board of
Directors was aware of these interests and considered them, among other
matters, in approving the Merger Agreement and the transactions contemplated
thereby.
 
  Options. Pursuant to the 1993 Incentive Stock Option Plan of Security, upon
a change in control of Security, all outstanding unvested options and limited
rights to acquire shares of Security Common Stock will become immediately
exercisable in full. Consummation of the Merger will constitute a "change in
control" for this purpose. Accordingly, the unvested employee stock options
held by Messrs. Argue, Gordon, Kamin, Schaefer, Schoendorf, Schuett, Jr. and
Schuett, Sr. will become fully vested as of the Effective Time under the terms
of the stock option agreements evidencing such options. Currently, such
executives have been granted options, which will not have vested by October 1,
1997, to purchase 38,000 shares of Security Common Stock, of which 1,000
shares with an exercise price of $41.50 would have vested on December 14,
1997, 28,000 shares with an exercise price of $25.00 would have vested on
December 17, 1997 and 9,000 shares with an exercise price of between $41.50
and $59.25 would have vested in 1998 through 2001.
 
  Existing Employment Agreements. Security is a party to employment agreements
with a term ending on December 31, 1997, with Messrs. Argue, Kamin, Schaefer,
Schoendorf, Schuett, Jr. and Schuett, Sr. Additionally, in the Merger
Agreement, M&I has agreed that Security may reinstate an employment agreement
with Mr. Gordon which will contain the same conditions as the employment
agreements described in the previous
 
                                      38
<PAGE>
 
sentence (amended as described below). These seven agreements will be referred
to hereafter collectively as the "Existing Employment Agreements." Prior to
taking into account the reductions described below, the Existing Employment
Agreements provide that, in the event of termination of the executive's
employment within twelve months following a "change in control" of Security,
the executive would be entitled to receive (a) severance pay based on the
average annual base salary and bonus over the previous five calendar years,
multiplied by the time remaining to the end of the term of the Existing
Employment Agreement, with a minimum value of 2.99 times Total Compensation
(defined to include W-2 compensation plus deferrals) for the last calendar
year, which minimum would be reduced, however, to the maximum amount necessary
to avoid imposition of the 20% golden parachute excise tax, and (b) an
additional retirement benefit (relevant for Messrs. Argue, Gordon and Schuett,
Jr., who have not accumulated full service credit) calculated under Security's
retirement plans, determined as if the executive was fully vested and had
accumulated additional service credit until the end of the employment term on
December 31, 1997 at a rate of Total Compensation equal to the executive's
Total Compensation immediately preceding the date of termination. As described
above, consummation of the Merger will constitute a "change in control" for
purposes of the Existing Employment Agreements. In connection with the Merger,
the parties have agreed (i) with the consent of the affected parties, that the
multiple used to determine the severance payments for Messrs. Schuett, Sr.,
Schaefer and Schoendorf will be reduced from 2.99 to 1 and (ii) with the
consent of all executives with Existing Employment Agreements, that the total
amount paid pursuant to the Existing Employment Agreements, when added to the
other "parachute payments" (within the meaning of Section 280G(b)(2)(A) of the
Code) which result from the "change in control," will be reduced, if
necessary, to avoid imposition of the 20% golden parachute excise tax. In the
Merger Agreement, in consideration for the concessions agreed to by the
executives, M&I has agreed to pay each of the executives, within 30 days
following the Effective Time, the severance payments described in clause (a)
above to which he is entitled (as reduced in the case of Messrs. Schuett, Sr.,
Schaefer and Schoendorf) even if his employment is not terminated. This will
result in payments to Messrs. Argue, Gordon, Kamin, Schaefer, Schoendorf,
Schuett, Jr. and Schuett, Sr. of approximately $765,000, $525,000, $665,000,
$900,000, $415,000, $500,000, and $1,100,000, respectively.
 
  New Employment Arrangement. M&I has entered into an employment arrangement
with Mr. Gordon whereby his base salary will continue to be $200,000 per year
for the one-year period after the Effective Time of the Merger and his
incentive opportunity will be $100,000 for such period. In consideration of
future services to be performed after the Merger, Mr. Gordon will be granted
approximately 10,000 shares of restricted stock in exchange for a payment of
one dollar per share. These shares will vest fully upon the completion by Mr.
Gordon of one year of service with M&I or upon a change in control of M&I,
whichever occurs first.
 
  ESOP. The executive officers of Security are participants in the ESOP. The
amendments being made to the ESOP in connection with the Merger and the
estimated benefits to be received by executive officers pursuant to such
amendments are described below under "Effect on Employee Benefits and Stock
Options."
 
  Rabbi Trusts. M&I has agreed that the rabbi trusts which fund Security's
SERP and the Nonqualified Deferred Compensation Trust may be amended to
provide that upon a change in control, an obligation will be triggered to (a)
fund the trusts at a level equal to 110% and 100% of the accrued benefits,
respectively, and (b) revalue the accrued benefits annually and deposit the
amount necessary to maintain the funding of each trust at such level.
Consummation of the Merger will constitute a change in control for purposes of
the rabbi trusts.
 
  Deferred Compensation Plans. M&I has agreed, among other things, that the
Deferred Compensation Plan for Officers, the Non-Employee Director Deferred
Compensation Plan and any similar arrangements may be amended to provide (a)
for the payment of that portion of a participant's benefits otherwise
scheduled to be made in 1997 on the earlier of the payment date otherwise
elected by the participant or the date which is one week prior to the
scheduled Effective Time, (b) that no amendment (other than the amendments
described in the Merger Agreement) may be made which would serve to accelerate
the payment of benefits or decrease the rate of interest and (c) to provide
that (i) participants will be given an election, with respect to the treatment
of their stock accounts, which is the same as the election being given to
shareholders of Security pursuant to the Merger Agreement, (ii) to the extent
necessary to conform to a participant's election, any cash credited to the
 
                                      39
<PAGE>
 
participant's account will be converted into additional shares of stock of M&I
based on the trading price of said stock and (iii) any cash credited to the
participant's account pursuant to a cash election will be credited thereafter
with an interest rate equal to Moody's Average Corporate Bond Yield Index
rather than the enhanced rate otherwise applicable under the plans.
 
  SERP. M&I has agreed that Security's Supplemental Executive Retirement Plan
(the "SERP") (a) will continue in effect following the Effective Time for the
benefit of the current participants therein and (b) may be amended to provide
that (i) in addition to any existing restrictions on amendment and
termination, the SERP may not be terminated or amended in any manner adverse
to participants who are participants as of March 14, 1997, (ii) generally, a
participant who retires at or after age 55 may elect to defer the commencement
of benefits under the SERP until age 62 and (iii) in calculating benefits
under the SERP, any benefit enhancements under Security's qualified pension
plan after March 14, 1997 will be disregarded.
 
  Non-Employee Director Retirement Plan. M&I has agreed that the Non-Employee
Director Retirement Plan may be amended to provide that (a) in addition to any
existing restrictions on amendment and termination, the Non-Employee Director
Plan may not be terminated or amended in any manner adverse to participants
who are participants as of March 14, 1997, and (b) a participant who retires
at or after age 55 may elect to defer the commencement of benefits under the
Non-Employee Director Retirement Plan until age 62. In addition, the Non-
Employee Director Retirement Plan will be amended (with the consent of
participants given as of March 14, 1997) as described in clause (c) of the
paragraph above entitled "Deferred Compensation Plans," except that cash
credited to a participant's account will not thereafter be credited with
interest.
 
  Annual Incentive Plan. Under the Annual Incentive Plan, participants are
eligible to receive awards ranging from 25% to 75% of base compensation. M&I
has agreed that the Annual Incentive Plan may be amended to provide that for
fiscal 1997, participants will receive a target bonus payment (50% of base
compensation), which payment is expected to be made in July, 1997, and for
that portion of fiscal 1998 ending on the earlier of (a) a participant's
termination of employment or (b) December 31, 1997, participants will receive
a prorated portion of the target bonus payment based on the number of months
which have elapsed during such period. Based on current earnings, the fiscal
1997 bonus payments would otherwise have equalled or exceeded the 50% target
bonus based on earnings through March 14, 1997. The prorated fiscal 1998 bonus
payments will be made on the earlier of a participant's termination of
employment or December 31, 1997. The foregoing would result in payments to
Messrs. Argue, Gordon, Kamin, Schaefer, Schoendorf, Schuett, Jr. and Schuett,
Sr. of approximately $72,500, $93,750, $65,000, $280,000, $100,000, $50,000
and $337,500, respectively, for the fiscal 1997 target bonus payment and,
assuming an October 1, 1997 termination date for all participants,
approximately $18,125, $25,000, $16,250, $70,000, $25,000, $12,500, and
$84,375, respectively, for the prorated fiscal 1998 target bonus payment.
 
  Indemnification; Directors' and Officers' Insurance. The Merger Agreement
provides that after the Effective Time, M&I will indemnify and hold harmless,
to the fullest extent provided by law, any person who has, prior to the
Effective Time, been a director, officer or employee of Security or its
subsidiaries (each such person, an "Indemnified Party") against any losses,
claims, damages, liabilities, costs, expenses, judgments, fines and amounts
paid in settlement in connection with any threatened or actual claim, action,
suit, proceeding or investigation (whether asserted or arising before or after
the Effective Time) (collectively, the "Actions"). In addition, in the event
of any such Action, the Indemnified Parties may retain counsel satisfactory to
them after consultation with the Company; provided that M&I has not (absent a
conflict of interest) assumed the defense thereof, and provided that certain
other limitations are met. M&I's obligations under this provision will
continue in full force and effect for a period of six years from the Effective
Time; provided, however, that all rights to indemnification in respect of a
claim asserted or made within such period shall continue until the final
disposition thereof. The Merger Agreement also provides that M&I will, subject
to the conditions set forth in the Merger Agreement, use its best efforts to
cause directors and officers of Security to be covered for a period of six
years from the Effective Time by a directors' and officers' liability
insurance policy equivalent to that maintained by Security, provided that M&I
will not be required to expend more than 200% of the current amount expended
by Security to procure such insurance.
 
                                      40
<PAGE>
 
EFFECT ON EMPLOYEE BENEFITS AND STOCK OPTIONS
 
  Employee Stock Options. At the Effective Time, all rights with respect to
Security Common Stock pursuant to Security employee stock options which
qualify as incentive stock options under Section 422 of the Code
(individually, an "ISO" and jointly, "ISOs") that are outstanding at the
Effective Time will be converted into and become rights with respect to M&I
Common Stock. M&I will assume each Security ISO in accordance with the terms
of the stock option plan under which it was issued and the stock option
agreement by which it is evidenced. From and after the Effective Time, (i)
each Security ISO assumed by M&I will be exercisable solely for shares of M&I
Common Stock, (ii) the number of shares of M&I Common Stock subject to each
Security ISO will be equal to the number of shares of Security Common Stock
subject to such Security ISO immediately prior to the Effective Time
multiplied by the "Exchange Ratio" implied in the Merger Agreement and (iii)
the per share exercise price under each Security ISO will be adjusted by
dividing the per share exercise price under such Security ISO by the Exchange
Ratio and rounding down to the nearest cent; provided, however, that the terms
of each Security ISO will, in accordance with its terms, be subject to further
adjustment as appropriate to reflect any stock split, stock dividend,
recapitalization or other similar transaction subsequent to the Effective
Time. It is intended that the foregoing assumption will be undertaken in a
manner that will not constitute a "modification" as defined in the Code as to
any Security ISO. Nearly all holders of nonqualified options over Security
Common Stock, to the extent they have not been exercised prior to the
Effective Time, have agreed to exchange their options for cash at the
Effective Time equal in amount to the excess of the Average Per Share
Consideration, as defined in the Merger Agreement, over the exercise price for
such option, times the number of shares covered by such option. Messrs. Argue,
Gordon, Kamin, Schaefer, Schoendorf, Schuett, Jr. and Schuett, Sr. hold
approximately 4,000, 17,952, 0, 194,000, 146,000, 28,000, and 240,000 non-
qualified stock options, respectively. All other executive officers and
directors of Security as a group hold approximately 136,000 non-qualified
options. The exercisability of such options prior to the Effective Time is
limited pursuant to the Merger Agreement; provided, however, that Security may
generally waive such restrictions with respect to no more than 500,000 shares
of Security Common Stock.
 
  Certain executive officers currently hold the following number of Security
ISOs which, if outstanding at the time of the Merger, will be converted into
rights with respect to M&I Common Stock as described above. Messrs. Argue,
Gordon, Kamin, Schaefer, Schoendorf, Schuett, Jr. and Schuett, Sr. hold
20,000, 27,048, 20,000, 20,000, 20,000, 20,000 and 20,000 vested and unvested
Security ISOs respectively.
 
  Generally. Except as described below under the headings "Severance Plan" and
"Employee Loan Program" and above in the section entitled, "Interests of
Certain Persons in the Merger," employees of Security who continue employment
with M&I ("Affected Employees") will be integrated into the welfare and
employee benefit plans of M&I as of January 1, 1998. Security's benefit plans
will generally continue in force until December 31, 1997. Affected Employees
will have their years of service with Security and its subsidiaries recognized
for purposes of eligibility and vesting under M&I's qualified and nonqualified
retirement, profit sharing or vacation plans or arrangements, and for purposes
of eligibility under M&I's welfare benefit plans. The cost of retiree medical
insurance for eligible Affected Employees will be borne by such Affected
Employees. M&I will, in general, waive all limitations as to preexisting
conditions and waiting periods with respect to participation and coverage
requirements applicable to Affected Employees under any welfare benefit plans
in which they are eligible to participate. The Merger will be deemed to
constitute a "change in control" under all qualified and non-qualified plans
and employment agreements of Security and its subsidiaries.
 
  Pension Plan and 401(k) Plan. Security's qualified pension plan will be
frozen on December 31, 1997 with full vesting as of the Effective Time and may
be terminated at the discretion of M&I. Accounts in the 401(k) plan of
participants who are employed by Security or its subsidiaries at the Effective
Time will be fully vested as of the Effective Time.
 
  ESOP. Generally, under the ESOP, shares are allocated based on a
participant's compensation up to $160,000. In the Merger Agreement, M&I has
agreed that (a) a pro rata contribution for 1997 will be made by Security to
the ESOP on the day prior to the Effective Time, which contribution will give
rise to an allocation to eligible participant accounts in proportion to their
compensation, (b) the ESOP will terminate and all account
 
                                      41
<PAGE>
 
balances will become fully vested and nonforfeitable as of the Effective Time,
and (c) the assets remaining in the ESOP, after payment by the ESOP of any
remaining indebtedness to Security, will be allocated among ESOP participants,
generally based on their relative account balances in the ESOP. The specific
method of allocation (including the treatment of allocations in excess of
Internal Revenue Code limitations) may be adjusted if such adjustment is
required in order to secure a favorable determination letter from the Internal
Revenue Service regarding the tax-qualified status of the ESOP upon its
termination. Distributions to ESOP participants will be made as soon as
practicable after the later to occur of the Effective Time and the receipt of
said determination letter. Under clause (c) above, allocations will be made to
Messrs. Argue, Gordon, Kamin, Schaefer, Schoendorf, Schuett, Jr. and Schuett,
Sr. representing the equivalent of approximately 3,170, 2,780, 3,020, 3,170,
3,170, 2,830 and 3,050 shares of Security Common Stock respectively.
 
  Severance Plan. The Security Change in Control Severance Plan will govern
terminations of employment which occur within two years following the
Effective Time, except for employees with (a) Existing Employment Agreements
(as discussed above in "Interests of Certain Persons in the Merger") or (b)
other employment agreements with Security or its subsidiaries, unless the
employee waives all rights to compensation, profit percentages, rights of
first refusal and severance under such employment agreements. The plan
provides severance pay and continued health and dental insurance for those
currently covered for a defined period, the length of which is determined by
the employee's job classification and years of service. In the case of an
employee of Security or its subsidiaries whose employment is terminated
between the eighteenth month following, and prior to the second anniversary
of, the Effective Time, such employee's entitlement to severance pay and
benefits will be reduced by two months for every one month which elapses from
such eighteenth month anniversary to the date of termination, until the
severance period is reduced to that contained in the M&I severance plan.
Severance is payable only (a) if M&I terminates the employee from the
employee's current position and does not offer the employee a position with
comparable pay and benefits at a location no greater than 25 miles from the
location where the employee was employed as of the Effective Time and (b) upon
completion by the employee of a complete and permanent release from all claims
arising from the employee's employment.
 
  Bonuses. In the Merger Agreement, M&I has agreed that bonuses for the
employees of Security and its subsidiaries, other than those employees
participating in Security's Annual Incentive Plan for fiscal 1997, will be
paid pursuant to the terms of such bonus plans, or, in the absence of a plan,
consistent with past practice of Security and its subsidiaries, except that
any other bonus amounts which, in a manner consistent with past practice, have
been accrued as of the end of fiscal 1997 may also be paid. All bonuses in
respect of fiscal 1998 which, in a manner consistent with past practice, are
accrued but unpaid as of the Effective Time will be paid promptly following
the Effective Time. In addition, in light of the amendment to the employment
agreements in which Messrs. Schuett, Sr., Schaefer and Schoendorf waived
approximately two years of severance payments, the Board of Directors of
Security established a bonus pool upon signing of the Merger Agreement of
$2,400,000 for employees of Security (the "Bonus Pool"). The Bonus Pool will
be used to (a) incent Security's employees to retain Security's customers, (b)
incent Security's employees to attain net income targets, and (c) retain key
Security employees during the period prior to the Effective Time. The Bonus
Pool will be administered by a committee of Messrs. Dennis J. Kuester of M&I
and Douglas S. Gordon and Robert A. Schaefer of Security, or such other
Security employees as are reasonably acceptable to M&I.
 
  Employee Loan Program. In the Merger Agreement, M&I has agreed that each
Affected Employee will have the ability to retain any loan provided to such
employee under Security's Employee Loan Program until its maturity and under
its existing terms and conditions. Any outstanding loan under the Employee
Loan Program of any employee of Security or its subsidiaries whose employment
is terminated following the Effective Time will be refinanced by M&I under its
loan program, unless the employee's credit history does not meet M&I's
standard loan criteria. The fact that the employee's employment has been
severed will not be taken into account in determining whether the employee
satisfies such criteria.
 
                                      42
<PAGE>
 
ACCOUNTING TREATMENT
 
  It is anticipated that the Merger will be treated as a purchase for
accounting purposes.
 
CERTAIN FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER
 
  The following is a discussion of the material U.S. federal income tax
consequences of the Merger to a Security Common Shareholder. The discussion
set forth below does not address all aspects of federal taxation and may not
apply to a holder subject to special treatment under the Code, such as a
holder that is a bank, an insurance company, a dealer in securities or foreign
currencies, a tax-exempt organization or that acquired its Security Common
Stock pursuant to the exercise of an employee stock option or otherwise as
compensation. In addition, this summary only applies to a Security Common
Shareholder holding its Security Common Stock as a capital asset and who is a
U.S. person (as defined in Section 7701(a)(30) of the Code (a "Holder")). This
discussion is based upon the Code, administrative pronouncements, judicial
decisions and Treasury Regulations in effect as of the date hereof, all of
which are subject to change (possibly with retroactive effect). No ruling will
be requested from the Internal Revenue Service (the "Service") regarding the
tax consequences of the Merger, and, accordingly, there can be no assurance
that the Service will agree with the discussion of the tax consequences of the
Merger set forth below. In addition, the discussion does not address the
state, local or foreign tax consequences of the Merger.
 
  EACH HOLDER OF SECURITY COMMON STOCK IS URGED TO CONSULT ITS TAX ADVISOR
WITH RESPECT TO THE FEDERAL, STATE, LOCAL AND FOREIGN TAX CONSEQUENCES OF THE
MERGER.
 
  Consummation of the Merger is conditioned upon the receipt by M&I of the
opinion of Godfrey & Kahn, S.C., counsel to M&I, and upon the receipt by
Security of the opinion of Skadden, Arps, Slate, Meagher & Flom LLP, counsel
to Security, each dated the Effective Time, on the basis of facts,
representations and assumptions set forth or referred to in such opinions
which are consistent with the state of facts existing at the Effective Time,
that the Merger will be treated for U.S. federal income tax purposes as a
reorganization within the meaning of Section 368(a) of the Code. The condition
that such opinions be delivered can be waived. Security will resolicit proxies
from Security Common Shareholders in the event that such opinions cannot be
delivered at the Effective Time because the federal income tax consequences
are materially different from those described. In rendering their opinions,
counsel will require and rely upon, and assume the accuracy of,
representations of M&I, Security, certain shareholders of Security and others.
Such opinions are not binding on the Service and would not prevent the Service
from challenging the U.S. federal income tax treatment of the Merger. Godfrey
& Kahn, S.C. may deliver the opinion referred to above in advance of the
Effective Time. See "THE MERGER--Conditions to the Merger."
 
  As discussed below, the U.S. federal income tax consequences of the Merger
to a Holder will depend on whether the Holder exchanges its Security Common
Stock for M&I Common Stock, cash or a combination thereof.
 
  Exchange Solely for M&I Common Stock. If, pursuant to the Merger, a Holder
exchanges all of the shares of Security Common Stock actually owned by it
solely for shares of M&I Common Stock, such Holder will not recognize any gain
or loss except in respect of cash received in lieu of a fractional share of
M&I Common Stock (as discussed below). The aggregate adjusted tax basis of the
shares of M&I Common Stock received in the exchange will be equal to the
aggregate adjusted tax basis of the shares of Security Common Stock
surrendered therefor (adjusted with respect to fractional shares), and the
holding period of such M&I Common Stock will include the period during which
such shares of Security Common Stock were held.
 
                                      43
<PAGE>
 
  Exchange Solely for Cash. In general, if, pursuant to the Merger, a Holder
exchanges all of the shares of Security Common Stock actually owned by it
solely for cash, such Holder will generally recognize capital gain or loss
equal to the difference between the amount of cash received and its adjusted
tax basis in the shares of Security Common Stock surrendered, which gain or
loss will be long-term capital gain or loss if the Holder's holding period
with respect to the shares of Security Common Stock surrendered is more than
one year. If, however, any such Holder constructively owns shares of Security
Common Stock that are exchanged for shares of M&I Common Stock in the Merger
or owns shares of M&I Common Stock actually or constructively after the
Merger, the consequences to such Holder may be similar to the consequences
described below under the heading "Exchange for M&I Common Stock and Cash,"
except that the amount of consideration, if any, treated as a dividend may not
be limited to the amount of such Holder's gain.
 
  Exchange for M&I Common Stock and Cash. If, pursuant to the Merger, a Holder
exchanges all of the shares of Security Common Stock actually owned by it for
a combination of M&I Common Stock and cash, the Holder will generally
recognize gain, but not loss, with respect to Security Common Stock
surrendered in an amount equal to the lesser of (i) the amount of gain
realized (i.e., the excess of the sum of the amount of cash and the fair
market value of M&I Common Stock received over the adjusted tax basis) and
(ii) the amount of cash received. For this purpose, gain or loss must be
calculated separately for each identifiable block of shares surrendered in the
exchange, and a loss realized on one block of shares may not be used to offset
a gain realized on another block of shares. Any recognized gain will generally
be long-term capital gain if the Holder's holding period with respect to the
stock is more than one year. If, however, the cash received has the effect of
the distribution of a dividend, the gain would be treated as a dividend to the
extent of the Holder's ratable share of Security's accumulated earnings and
profits. See "Possible Treatment of Cash as a Dividend."
 
  The aggregate tax basis of M&I Common Stock received by a Holder that
exchanges its shares of Security Common Stock for a combination of M&I Common
Stock and cash pursuant to the Merger will be the same as the aggregate
adjusted tax basis of the shares of Security Common Stock surrendered
therefor, decreased by the cash received and increased by any recognized gain
(whether capital gain or ordinary income). The holding period of such M&I
Common Stock will include the holding period of the shares of Security Common
Stock surrendered therefor.
 
  Possible Treatment of Cash as a Dividend. In general, the determination of
whether the gain recognized in the exchange will be treated as capital gain or
has the effect of a distribution of a dividend depends upon whether, and to
what extent, the exchange reduces the Holder's deemed percentage stock
ownership of M&I. For purposes of this determination, the Holder is treated as
if it first exchanged all of its shares of Security Common Stock solely for
M&I Common Stock and then M&I immediately redeemed (the "deemed redemption") a
portion of such M&I Common Stock in exchange for the cash the Holder actually
received. The gain recognized in the exchange followed by a deemed redemption
will be treated as capital gain if the deemed redemption is (i) "substantially
disproportionate" with respect to the Holder, or (ii) not essentially
equivalent to a dividend.
 
  The deemed redemption, generally, will be "substantially disproportionate"
with respect to a Holder if the percentage described in (ii) below is less
than 80% of the percentage described in (i) below. Whether the deemed
redemption is "not essentially equivalent to a dividend" with respect to a
Holder will depend upon the Holder's particular circumstances. At a minimum,
however, in order for the deemed redemption to be "not essentially equivalent
to a dividend," the deemed redemption must result in a "meaningful reduction"
in the Holder's deemed actual and constructive percentage stock ownership of
M&I. In general, that determination requires a comparison of (i) the
percentage of the outstanding stock of M&I the Holder is deemed actually and
constructively to own immediately before the deemed redemption and (ii) the
percentage of the outstanding stock of M&I the Holder actually and
constructively owns immediately after the deemed redemption. In applying the
foregoing tests, a Holder is deemed to own stock owned and, in some cases,
constructively owned by certain family members, by certain estates and trusts
of which the Holder is a beneficiary, and by certain affiliated entities, as
well as stock subject to an option actually or constructively owned by the
stockholder or such other
 
                                      44
<PAGE>
 
persons. As these rules are complex, each Holder that may be subject to these
rules should consult its tax advisor. The Service has ruled that a relatively
minor reduction in the percentage stock ownership of a minority shareholder in
a publicly held corporation whose relative stock interest is minimal and who
exercises no control with respect to corporate affairs is a "meaningful
reduction."
 
  Cash Received in Lieu of a Fractional Share. Based upon the current ruling
position of the Service, cash received by a Security Common Stockholder in
lieu of a fractional share of M&I Common Stock will be treated as received in
exchange for such fractional share, and gain or loss will be recognized,
measured by the difference between the amount of cash received and the portion
of the basis of the share of Security Common Stock allocable to such
fractional interest. Such gain or loss should be long-term capital gain or
loss if the holding period for such share of Security Common Stock was more
than one year.
 
  Bad Debt Reserve Recapture Due to Bank Merger. Under prior law, Security
Bank accounted for bad debts using the reserve method under Section 593 of the
Code. Recent amendments to the Code (the "Amendments") eliminated the reserve
method under Section 593 effective for taxable years beginning after December
31, 1995. The Amendments require thrift institutions that are treated as large
banks, such as Security Bank, to recapture their post-1987 bad debt reserves
ratably over six taxable years. Security has already accrued the deferred tax
liability attributable to the post-1987 bad debt reserve to be recaptured.
 
  Under the Amendments, whether any or all of Security Bank's pre-1988 bad
debt reserve in the amount of $104.4 million would have to be recaptured as a
result of the merger of Security Bank into M&I Marshall & Ilsley Bank (the
"Bank Merger") has been left to be specified in Treasury regulations. Under
the legislative history to the Amendments, such regulations are to provide
that "if an institution with a pre-1988 reserve is merged or liquidated tax-
free into a bank, the pre-1988 reserve should not be restored to income by
reason of the merger or liquidation. Rather, the bank will inherit the pre-
1988 reserve . . . of the former thrift institution, and Section 593(e) will
apply to the bank as if it were a thrift institution." Although there can be
no assurance as to the content or operation of such Treasury regulations or as
to when such regulations might be issued, based on the legislative history to
the Amendments, it appears that the Bank Merger should not trigger the
recapture of Security Bank's pre-1988 reserve, and that, instead, M&I's bank
subsidiary will succeed to such reserve. Nevertheless, in certain
circumstances, the reserve could still be subject to future recapture, either
in whole or in part.
 
RESALE OF M&I COMMON STOCK BY AFFILIATES
 
  The shares of M&I Common Stock to be issued to former shareholders of
Security upon consummation of the Merger have been registered under the
Securities Act. Such shares may be traded freely and without restriction by
those shareholders not deemed to be "affiliates" (as such term is defined
under the Securities Act) of Security. "Affiliates" are generally defined as
persons who control, are controlled by, or are under common control with
Security. Accordingly, "affiliates" will generally include directors and
executive officers of Security. Shares of M&I Common Stock received by those
shareholders of Security deemed to be "affiliates" may not be sold without
registration, except as permitted by Rules 145 and 144 under the Securities
Act, or as otherwise permitted under the Securities Act. This Proxy Statement-
Prospectus does not cover resales of any M&I Common Stock received by
"affiliates" of Security. Security has agreed to use reasonable efforts to
cause each person identified as an affiliate of Security to enter into an
agreement which provides that such affiliate will not transfer any M&I Common
Stock received in the Merger except in compliance with the Securities Act.
 
NO APPRAISAL OR DISSENTERS' RIGHTS
 
  Under Section 180.1302(4) of the WBCL, subject to certain exceptions
inapplicable to the Merger, holders of shares of a Wisconsin corporation
quoted on the Nasdaq National Market on the record date fixed to determine
shareholders entitled to notice of a shareholders meeting at which
shareholders are to vote on a merger are not entitled to appraisal or
dissenters' rights. Security Common Stock was quoted on the Nasdaq National
Market as of the Record Date. Accordingly, holders of Security Common Stock
have no appraisal or dissenters' rights with respect to the Merger.
 
 
                                      45
<PAGE>
 
                         CERTAIN RELATED TRANSACTIONS
 
DATA PROCESSING SERVICES AGREEMENT
 
  M&I Data Services and Security are planning to negotiate a Data Processing
Services Agreement (the "Data Processing Agreement") pursuant to which M&I
Data Services would perform certain data processing services for Security at
M&I Data Services' then current standard published prices, subject to certain
discounts, plus reimbursement of certain conversion and start-up charges
including reasonable out-of-pocket expenses. It is anticipated that the Data
Processing Agreement will have an initial term of six years, and on each
anniversary would be renewed for an additional year absent advance notice to
the contrary, thereby restoring the full term of the Data Processing Agreement
to six years. M&I and Security believe that any such Data Processing Agreement
would be the result of arms-length negotiations between the parties and would
contain similar terms to agreements negotiated between M&I Data Services and
unrelated parties.
 
TRUST SERVICES
 
  Marshall & Ilsley Trust Company, a wholly-owned subsidiary of M&I, provides
certain trust services for Security's employee benefit plans. In 1996,
Security paid Marshall & Ilsley Trust Company approximately $101,200 for these
services. Marshall & Ilsley Trust Company will not have beneficial ownership
of any of the shares of Security Common Stock held in Security's employee
benefit plans as of the Record Date.
 
                       CERTAIN REGULATORY CONSIDERATIONS
 
  The Merger is subject to the approval of the Federal Reserve Board under
Sections 3 and 4 of the BHCA and DFI under Wisconsin statutes. M&I filed the
necessary applications with these regulatory authorities on April 1, 1997.
 
FEDERAL RESERVE BOARD APPROVAL
 
  Section 3 of the BHCA requires that the Federal Reserve Board take into
consideration, among other factors, the financial and managerial resources and
future prospects of the institutions and the convenience and needs of the
communities to be served. The BHCA prohibits the Federal Reserve Board from
approving the Merger (i) if it would result in a monopoly or be in furtherance
of any combination or conspiracy to monopolize or to attempt to monopolize the
business of banking in any part of the United States or (ii) if its effect in
any section of the country may be substantially to lessen competition or to
tend to create a monopoly, or if it would in any other manner be a restraint
of trade, unless the Federal Reserve Board finds that the anti-competitive
effects of the Merger are clearly outweighed by the public interest and the
probable effect of the transaction in meeting the convenience and needs of the
communities to be served. The Community Reinvestment Act of 1978, as amended
("CRA"), also requires that the Federal Reserve Board, in deciding whether to
approve the Merger, assess the record of performance of the bank subsidiaries
of M&I and Security in meeting the credit needs of the entire community,
including low- and moderate-income neighborhoods, served by such bank
subsidiaries. The Federal Reserve Board has also indicated that it will not
approve a significant acquisition unless the resulting institution has
adequate regulatory capital, taking into account, among other things, the
nature of the business and operations and plans for expansion.
 
  Under Section 4 of the BHCA and related regulations, the Federal Reserve
Board must assess whether the performance of M&I's and Security's nonbanking
activities on a combined basis can reasonably be expected to produce benefits
to the public such as greater convenience, increased competition, or gains in
efficiency, that outweigh any possible adverse effects, such as undue
concentration of resources, decreased or unfair competition, conflicts of
interest and unsound banking practices. This assessment also includes an
evaluation of the financial and managerial resources of M&I and Security and
the effect of the Merger on those resources.
 
 
                                      46
<PAGE>
 
  Pursuant to the BHCA, the Merger may not be consummated until the 30th day
or, in the event that the Federal Reserve Board receives no adverse
competitive comments from the Department of Justice, the 15th day following
the date of Federal Reserve Board approval, during which time the Department
of Justice may challenge the Merger on antitrust grounds. The commencement of
such an antitrust action would stay the effectiveness of the Federal Reserve
Board's approval unless a court specifically orders otherwise.
 
  M&I and Security believe that while divestitures will be required in one or
more of the markets served by M&I and Security, antitrust concerns are not
expected to preclude the consummation of the Merger. The Federal Reserve Board
generally evaluates the possible anti-competitive effects of a bank merger or
acquisition by measuring the effect of the merger or acquisition on market
share concentration, utilizing branch deposits as the indicator of a bank's
market share in a local geographic market (such as a metropolitan area or
county). If the deposit market share data for a geographic market indicates
that the overall concentration in that market is above a specified level and
the merger or acquisition causes the concentration to increase by a specified
amount, the Federal Reserve Board has in the past generally required the
divestiture of certain banking operations, although there have also been
occasions where mergers or acquisitions were approved notwithstanding the
presence of combined market shares in excess of such specified levels. The
Federal Reserve Board also evaluates other aspects of the possible anti-
competitive effects of the merger or acquisition. Based on the treatment of
prior mergers and acquisitions involving other parties, M&I anticipates that
certain divestitures may be required by the Federal Reserve Board or the
Department of Justice, and M&I has filed applications with the Federal Reserve
Board proposing the divestiture of certain bank branches in the State of
Wisconsin. At the present time, M&I management has preliminarily identified
branches with total deposits of approximately $125 million as candidates for
divestiture. There can be no assurance as to the location and amount of
divestitures that will ultimately be required in connection with regulatory
approval of the Merger. The Federal Reserve Board has in the past generally
required that any divestitures be made or agreed to prior to the consummation
of the merger with respect to which approval is sought.
 
DEPARTMENT OF FINANCIAL INSTITUTIONS APPROVAL
 
  Section 221.0901(6) of the Wisconsin Statutes requires DFI to consider the
following factors in connection with its decision to approve or disapprove the
Merger: (i) given the financial and managerial resources and future prospects
of M&I and Security, will the Merger be contrary to the best interests of the
shareholders or customers of Security; (ii) will the Merger be detrimental to
the safety and soundness of any subsidiary or affiliate of M&I or Security;
(iii) has M&I and its directors and executive officers established a record of
sound performance, efficient management, financial responsibility and
integrity such that the Merger will be in the best interests of the
depositors, other customers, creditors or shareholders of M&I and Security;
and (iv) has M&I received a rating of "needs to improve" or "substantial
noncompliance" with the CRA. In addition to these requirements under Section
221.0901 of the Wisconsin Statutes, DFI may not approve the transaction if (i)
after completion of the Merger, M&I will control 30% or more of the total
amount of deposits of insured depository institutions in Wisconsin; or (ii)
Security's bank subsidiary has been in existence for less than five years.
 
  M&I and Security believe that the Merger meets all of the criteria under
which DFI must evaluate the transaction.
 
                                      47
<PAGE>
 
                              UNAUDITED PRO FORMA
                        CONDENSED FINANCIAL INFORMATION
 
  The following unaudited Pro Forma Condensed Financial Information and
explanatory notes are presented to show the impact on the historical financial
position and results of operations of M&I from the proposed Merger with
Security.
 
  In accordance with the Merger Agreement, each share of Security's Common
Stock outstanding at the Effective Time will be converted in the Merger into
the right to receive, at the election of the holder, M&I Common Stock, cash or
some combination thereof provided that, the aggregate number of shares of M&I
Common Stock that shall be issued in the Merger shall be equal to or nearly
equal to 12,327,390 shares and the cash consideration shall be equal to
$376,335,605. Based on the closing price of M&I stock on March 14, 1997 of
$37.3125, the average per share consideration to Security shareholders was
approximately $92.00 per share payable approximately 55% in M&I Common Stock
and 45% in cash.
 
  The unaudited Pro Forma Condensed Financial Information reflects the Merger
using the purchase method of accounting. See "THE MERGER-Accounting
Treatment". The cash component of the purchase price is expected to be funded
by the liquidation of investment securities held by Security as available for
sale.
 
  The unaudited Pro Forma Condensed Balance Sheet assumes that the Merger was
consummated on March 31, 1997. Certain amounts in Security's historical
balance sheet as shown have been reclassified to conform to M&I's
presentation. The unaudited Pro Forma Condensed Statements of Income assume
that the Merger was consummated on January 1st of the indicated period and
reflect the consolidation of the results of operations of M&I and Security for
the three months ended March 31, 1997 and for the twelve months ended December
31, 1996, which is M&I's fiscal year end. Security's historical results of
operations for the twelve months ended December 31, 1996, as shown in the
unaudited Pro Forma Condensed Statement of Income have been restated to
conform to M&I's fiscal year end.
 
  The unaudited Pro Forma Condensed Financial Information reflects the Merger
based on preliminary purchase accounting adjustments. Estimates relating to
the fair value of certain assets, liabilities and other items have been made
as more fully described in the Notes to the unaudited Pro Forma Condensed
Financial Information. Actual adjustments, which may include adjustments to
additional assets, liabilities and other items, will be made on the basis of
appraisals and evaluations as of the Effective Time and, therefore, will
differ from those reflected in the unaudited Pro Forma Condensed Financial
Information.
 
  The consummation of the Merger is dependent upon obtaining regulatory
approvals, which may necessitate divestitures of certain bank branches. The
ultimate composition of the divestitures has not been finalized, and
accordingly no adjustment for divestitures has been included in the unaudited
Pro Forma Condensed Financial Information. However, at the present time, M&I
management has preliminarily identified seven branches with total deposits of
approximately $125 million as candidates for divestiture. There can be no
assurance, however, as to the amount of divestiture that will ultimately be
required in connection with regulatory approval of the Merger.
 
  The combined company expects to achieve substantial merger benefits
primarily in the area of operating cost savings. The unaudited pro forma
earnings, which do not reflect any direct costs or potential savings which are
expected to result from the consolidation of operations of M&I and Security,
are not indicative of the results of future operations. No assurances can be
given with respect to the ultimate level of cost savings to be realized.
 
  The following information should be read in conjunction with and is
qualified in its entirety by the consolidated financial statements and
accompanying notes of M&I and Security included in the documents described
under "INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE."
 
  The unaudited Pro Forma Condensed Financial Information is intended for
information purposes and is not necessarily indicative of the future financial
position or future results of the combined company or of the financial
position or the results of operations of the combined company that would have
actually occurred had the Merger been in effect as of the date or for the
period presented.
 
                                      48
<PAGE>
 
                       PRO FORMA CONDENSED BALANCE SHEET
 
                             (DOLLARS IN THOUSANDS)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                              AT MARCH 31, 1997
                          -------------------------------------------------------------------------
                                                   M&I AND
                                                  SECURITY    PRO FORMA                  PRO FORMA
                              M&I      SECURITY   COMBINED   ADJUSTMENTS                 COMBINED
                          ----------- ---------- ----------- -----------                -----------
<S>                       <C>         <C>        <C>         <C>                        <C>
         ASSETS
Cash and cash
 equivalents............  $   848,225 $   31,107 $   879,332                            $   879,332
Trading securities and
 other short-term
 investments............       90,215        --       90,215                                 90,215
Investment securities:
 Available for sale.....    2,977,094    718,677   3,695,771  ($376,336)(1)(2)            3,319,435
 Held to maturity.......      812,122        --      812,122                                812,122
Loans and leases........    9,576,716  2,797,852  12,374,568                             12,374,568
Less: Allowance for loan
 losses.................      154,599     40,712     195,311                                195,311
                          ----------- ---------- -----------  ---------                 -----------
Net loans and leases....    9,422,117  2,757,140  12,179,257        --                   12,179,257
Premises and equipment,
 net....................      318,092     24,358     342,450    (10,000)(3)                 332,450
Intangibles.............       74,272      2,424      76,696    357,420 (1)(2)(3)(4)(5)     434,116
Other assets............      348,079    124,749     472,828      3,899 (4)                 476,727
                          ----------- ---------- -----------  ---------                 -----------
     Total Assets.......  $14,890,216 $3,658,455 $18,548,671  $ (25,017)                $18,523,654
                          =========== ========== ===========  =========                 ===========
    LIABILITIES AND
  SHAREHOLDERS' EQUITY
Deposits
 Noninterest bearing....  $ 2,261,330 $   28,065 $ 2,289,395                            $ 2,289,395
 Interest bearing.......    8,574,325  2,282,321  10,856,646                             10,856,646
                          ----------- ---------- -----------  ---------                 -----------
Total deposits..........   10,835,655  2,310,386  13,146,041        --                   13,146,041
Total borrowings........    2,406,614    679,670   3,086,284                              3,086,284
Accrued expenses and
 other liabilities......      367,776     90,243     458,019  $  93,173 (1)(5)              551,192
                          ----------- ---------- -----------  ---------                 -----------
     Total liabilities..   13,610,045  3,080,299  16,690,344     93,173                  16,783,517
Shareholders' equity
 Preferred stock........          685        --          685                                    685
 Common stock...........       99,494     10,810     110,304      1,518 (1)                 111,822
 Additional paid-in
  capital...............      209,855    260,550     470,405    187,088 (1)                 657,493
 Retained earnings......    1,246,450    402,010   1,648,460   (402,010)(1)               1,246,450
 Net unrealized gains
  on securities
  available for sale,
  net of tax............       11,043      6,420      17,463     (6,420)(1)                  11,043
 Less:
   Treasury stock, at
    cost................      286,186     81,181     367,367    (81,181)(1)                 286,186
   Unearned ESOP
    compensation........          --      14,187      14,187    (14,187)(1)                     --
   Other deferred
    compensation........        1,170      6,266       7,436     (6,266)(1)                   1,170
                          ----------- ---------- -----------  ---------                 -----------
     Total shareholders'
      equity............    1,280,171    578,156   1,858,327   (118,190)                  1,740,137
                          ----------- ---------- -----------  ---------                 -----------
     Total Liabilities
      and Shareholders'
      Equity............  $14,890,216 $3,658,455 $18,548,671  $ (25,017)                $18,523,654
                          =========== ========== ===========  =========                 ===========
</TABLE>
 
      See Notes to the Unaudited Pro Forma Condensed Financial Information
 
                                       49
<PAGE>
 
                    PRO FORMA CONDENSED STATEMENT OF INCOME
 
                 (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                              FOR THE THREE MONTHS ENDED MARCH 31, 1997
                           -----------------------------------------------------
                                             M&I AND
                                             SECURITY  PRO FORMA       PRO FORMA
                             M&I    SECURITY COMBINED ADJUSTMENTS      COMBINED
                           -------- -------- -------- -----------      ---------
<S>                        <C>      <C>      <C>      <C>              <C>
INTEREST INCOME
 Loans and leases........  $194,946 $56,560  $251,506                  $251,506
 Investment securities...    60,099  11,720    71,819   ($6,496)(7)(8)   65,323
 Trading securities and
  other short-term in-
  vestments..............     2,878     --      2,878                     2,878
                           -------- -------  --------   -------        --------
   Total interest in-
    come.................   257,923  68,280   326,203    (6,496)        319,707
INTEREST EXPENSE
 Deposits................    94,309  26,719   121,028                   121,028
 Borrowings..............    33,972   9,559    43,531                    43,531
                           -------- -------  --------   -------        --------
   Total interest ex-
    pense................   128,281  36,278   164,559       --          164,559
                           -------- -------  --------   -------        --------
Net interest income......   129,642  32,002   161,644    (6,496)        155,148
Provision for loan loss-
 es......................     4,311     --      4,311                     4,311
                           -------- -------  --------   -------        --------
Net interest income after
 provision for losses....   125,331  32,002   157,333    (6,496)        150,837
OTHER INCOME
 Data processing servic-
  es.....................    80,140     --     80,140                    80,140
 Trust services..........    18,931     --     18,931                    18,931
 Securities gains (loss-
  es)....................       803     --        803                       803
 Other, net..............    37,721   5,840    43,561                    43,561
                           -------- -------  --------   -------        --------
   Total other income....   137,595   5,840   143,435       --          143,435
OTHER EXPENSE
 Salaries and employee
  benefits...............   105,382   9,520   114,902                   114,902
 Net occupancy...........    10,130   1,321    11,451                    11,451
 Equipment...............    20,864     650    21,514                    21,514
 Payments to regulatory
  agencies...............       601     372       973                       973
 Amortization............     3,014     194     3,208     4,793 (9)       8,001
 Other...................    40,776   5,627    46,403                    46,403
                           -------- -------  --------   -------        --------
   Total other expense...   180,767  17,684   198,451     4,793         203,244
                           -------- -------  --------   -------        --------
Income before income tax-
 es......................    82,159  20,158   102,317   (11,289)         91,028
Provision for income tax-
 es......................    27,360   6,634    33,994    (3,411)(10)     30,583
                           -------- -------  --------   -------        --------
Net income...............  $ 54,799 $13,524  $ 68,323   ($7,878)       $ 60,445
                           ======== =======  ========   =======        ========
NET INCOME PER COMMON
 SHARE (11):
 Primary.................  $   0.57 $  1.45                            $   0.55
 Fully diluted...........      0.56    1.45                                0.55
</TABLE>
 
      See Notes to the Unaudited Pro Forma Condensed Financial Information
 
                                       50
<PAGE>
 
                    PRO FORMA CONDENSED STATEMENT OF INCOME
 
                 (DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                             FOR THE TWELVE MONTHS ENDED DECEMBER 31, 1996
                          ----------------------------------------------------------
                                              M&I AND
                                              SECURITY   PRO FORMA        PRO FORMA
                            M&I    SECURITY   COMBINED  ADJUSTMENTS        COMBINED
                          -------- --------  ---------- -----------       ----------
<S>                       <C>      <C>       <C>        <C>               <C>
INTEREST INCOME
 Loans and leases.......  $758,955 $211,259  $  970,214                   $  970,214
 Investment securi-
  ties..................   202,255   44,546     246,801  ($25,984)(7)(8)     220,817
 Trading securities and
  other short-term in-
  vestments.............    10,226      --       10,226                       10,226
                          -------- --------  ----------  --------         ----------
   Total interest in-
    come................   971,436  255,805   1,227,241   (25,984)         1,201,257
INTEREST EXPENSE
 Deposits...............   360,838  104,025     464,863                      464,863
 Borrowings.............   104,879   30,236     135,115                      135,115
                          -------- --------  ----------  --------         ----------
   Total interest ex-
    pense...............   465,717  134,261     599,978                      599,978
                          -------- --------  ----------  --------         ----------
Net interest income.....   505,719  121,544     627,263   (25,984)           601,279
Provision for loan loss-
 es.....................    15,194    3,866      19,060                       19,060
                          -------- --------  ----------  --------         ----------
Net interest income af-
 ter provision for loan
 losses.................   490,525  117,678     608,203   (25,984)           582,219
OTHER INCOME
 Data processing serv-
  ices..................   268,526      --      268,526                      268,526
 Trust services.........    70,190      --       70,190                       70,190
 Net securities gains
  (losses)..............    14,876       (9)     14,867                       14,867
 Other, net.............   149,728   21,930     171,658                      171,658
                          -------- --------  ----------  --------         ----------
   Total other income...   503,320   21,921     525,241                      525,241
OTHER EXPENSE
 Salaries and employee
  benefits..............   382,430   36,544     418,974                      418,974
 Net occupancy..........    39,215    5,061      44,276                       44,276
 Equipment..............    77,250    2,651      79,901                       79,901
 Payments to regulatory
  agencies..............     4,791   17,012      21,803                       21,803
 Amortization...........    11,121      201      11,322    19,172 (9)         30,494
 Other..................   165,897   26,873     192,770                      192,770
                          -------- --------  ----------  --------         ----------
   Total other expense..   680,704   88,342     769,046    19,172            788,218
                          -------- --------  ----------  --------         ----------
Income before income
 taxes..................   313,141   51,257     364,398   (45,156)           319,242
Provision for income
 taxes..................   109,711   17,307     127,018   (13,644)(10)       113,374
                          -------- --------  ----------  --------         ----------
Net income..............  $203,430 $ 33,950  $  237,380  ($31,512)        $  205,868
                          ======== ========  ==========  ========         ==========
Net Income Per Common
 Share (11):
 Primary................  $   2.07 $   3.63                               $     1.85
 Fully diluted..........      2.02     3.60                                     1.82
</TABLE>
 
      See Notes to the Unaudited Pro Forma Condensed Financial Information
 
                                       51
<PAGE>
 
                        NOTES TO THE UNAUDITED PRO FORMA
                        CONDENSED FINANCIAL INFORMATION
 
          (DOLLARS IN THOUSANDS, SHARES AND PER SHARE AMOUNTS ACTUALS)
 
  The unaudited Pro Forma Condensed Financial Information is based on the
following adjustments and related assumptions. The actual purchase accounting
adjustments will be made on the basis of appraisals and evaluations as of the
date of consummation of the Merger and, therefore, will differ from those
reflected in the unaudited Pro Forma Condensed Financial Information.
 
  A summary of the purchase accounting adjustments to record the Merger used in
preparation of the unaudited Pro Forma Condensed Balance Sheet is as follows:
 
                              INCREASE (DECREASE)
<TABLE>
- -------------------------------------------------------------------------------
<CAPTION>
            INVESTMENT   PREMISES                       ACCRUED
ADJUSTMENT  SECURITIES     AND                         EXPENSES
REFERENCE   AVAILABLE   EQUIPMENT,             OTHER   AND OTHER  SHAREHOLDERS'
  NUMBER     FOR SALE      NET     INTANGIBLES ASSETS LIABILITIES    EQUITY
- ----------  ----------  ---------- ----------- ------ ----------- -------------
<S>         <C>         <C>        <C>         <C>    <C>         <C>
  (1)(2)    ($376,336)        --    $243,959      --   ($14,187)    ($118,190)
   (3)            --      (10,000)    10,000      --        --            --
   (4)            --          --      (3,899)   3,899       --            --
   (5)            --          --     107,360      --    107,360           --
            ---------    --------   --------   ------  --------     ---------
            ($376,336)   ($10,000)  $357,420   $3,899  $ 93,173     ($118,190)
            =========    ========   ========   ======  ========     =========
</TABLE>
 
  THE PURCHASE ACCOUNTING ADJUSTMENTS TO RECORD THE MERGER USED IN THE
PREPARATION OF THE UNAUDITED PRO FORMA CONDENSED BALANCE SHEET ARE:
 
<TABLE>
<CAPTION>
                                                         MARCH 31, 1997
                                                      ----------------------
<S>                                                   <C>         <C>
(1)Security Capital Corporation at:
    Common Stock issued.............................. 10,810,000
    Treasury stock to be canceled.................... (1,607,068)
    Restricted stock unawarded to be canceled........   (112,700)
                                                      ----------
  Security Common Stock outstanding as adjusted(a)...              9,090,232(a)
  Implied Exchange Ratio.............................                 1.3561
                                                                  ----------
  M&I Common Stock to be issued......................             12,327,390
  M&I Common Stock price.............................             $  37.3125
                                                                  ----------
  Assumed M&I Common Stock consideration.............      55.00% $  459,966
  Cash Consideration.................................      45.00%    376,336
                                                      ----------  ----------
  Assumed total consideration........................     100.00% $  836,302
  Historical net assets acquired:
   Total stockholders' equity                         $  578,156
   Assumed payout of ESOP note payable...............     14,187
   Accrue payout of nonqualified stock options.......    (35,368)
                                                      ----------
  Assumed historical net assets acquired(b)..........                556,975(b)
                                                                  ----------
  Assumed premium to allocate........................             $  279,327
                                                                  ==========
  Adjustments to fair value of net assets acquired:
   Premises and equipment............................             $  (10,000)
   Other liabilities.................................                (48,413)
   Deferred income taxes.............................                (19,680)
   Intangibles.......................................                357,420
                                                                  ----------
  Assumed adjustments to fair value of net assets
   acquired..........................................             $  279,327
                                                                  ==========
</TABLE>
 
                                       52
<PAGE>
 
                       NOTES TO THE UNAUDITED PRO FORMA
                 CONDENSED FINANCIAL INFORMATION--(CONTINUED)
 
  --------
    (a) The number of shares of Security's Common Stock to be exchanged will
  be those outstanding on the last day of the Valuation Period. The number of
  Security's shares outstanding on the indicated date, as adjusted, has been
  used in the pro forma computations.
 
    (b) The historical net assets acquired will be determined at the
  Effective Time. The historical net assets, as adjusted, for Security as of
  the indicated date has been used in the pro forma computations.
 
(2) The unaudited Pro Forma Condensed Financial Information assumes the
    funding of the cash component of the consideration is provided by the
    liquidation of investment securities available for sale.
 
(3) Reflects the preliminary estimate of writedowns associated with duplicate
    facilities, equipment and leasehold interests to be disposed of.
 
(4) Represents the estimated net tax asset associated with adjustments to fair
    value of net assets acquired and the accrued payout for nonqualified stock
    options assuming an income tax rate of 40%.
 
(5) Reflects the preliminary estimates of legal, accounting and investment
    bankers' fees associated with the Merger, costs to convert Security's
    processing systems to M&I systems, severance benefits associated with the
    elimination of duplicate employment positions at Security, incentive stock
    option plans which will roll into M&I and the accrued payout for
    nonqualified stock options.
 
(6) Represents preliminary estimates of identifiable intangibles (mortgage
    servicing rights and core deposit premiums) and goodwill. Since the final
    determination of adjustments to assets and liabilities will be made based
    upon the fair values as of the Effective Time and after appraisals and
    evaluations are complete, the final amounts will differ from the estimates
    provided herein.
 
  THE PURCHASE ACCOUNTING ADJUSTMENTS TO RECORD THE MERGER USED IN THE
PREPARATION OF THE UNAUDITED PRO FORMA CONDENSED STATEMENTS OF INCOME ARE
SUMMARIZED BELOW:
 
<TABLE>
<CAPTION>
                                                 THREE MONTHS    TWELVE MONTHS
                                                    ENDED            ENDED
                                                MARCH 31, 1997 DECEMBER 31, 1996
                                                -------------- -----------------
<S>                                         <C> <C>            <C>
(7) Reflects the estimated reduction in
    interest income from investment
    securities liquidated to fund the cash
    component of the Merger consideration
    assuming an interest rate of 6.25%....         $(5,880)        $(23,520)
(8) Reflects the estimated amortization of
    the premium related to investment
    securities assumed to be retained on a
    straight-line basis over the estimated
    maturities of the affected securities
    using an estimated weighted average
    life of 3.6 years.....................            (616)          (2,464)
                                                   -------         --------
  Estimated total impact on interest in-
   come...................................         $(6,496)        $(25,984)
                                                   =======         ========
(9) Reflects the amortization on a
    straight-line basis of identifiable
    intangibles and goodwill assuming the
    following estimated lives (in years):
    Mortgage servicing rights.............   10
    Core deposit premium..................   10
    Goodwill..............................   25    $ 4,793         $ 19,172
                                                   =======         ========
</TABLE>
 
(10) Income tax expense on pro forma adjustments is reflected using a 40% tax
     rate.
 
(11) The pro forma earnings per share include the effect of the adjustments
     described above, the issuance of 12,327,390 shares of M&I Common Stock
     and the common stock equivalents associated with incentive stock option
     plans which will roll into M&I and are assumed to be outstanding
     throughout the periods presented.
 
                                      53
<PAGE>
 
                       DESCRIPTION OF M&I CAPITAL STOCK
 
IN GENERAL
 
  The authorized capital stock of M&I currently consists of 160,000,000 shares
of M&I Common Stock, $1.00 par value, and 5,000,000 shares of Preferred Stock,
$1.00 par value (the "M&I Preferred Stock"), of which 2,000,000 shares have
been designated by the M&I Board of Directors as Series A Convertible
Preferred Stock, $1.00 par value (the "M&I Series A Preferred Stock"). As of
April 30, 1997, 88,639,389 shares of M&I Common Stock were outstanding and
685,314 shares of M&I Series A Preferred Stock were outstanding. The M&I
Common Stock is quoted on the Nasdaq National Market. The M&I Series A
Preferred Stock is not publicly traded.
 
M&I COMMON STOCK
 
  The following description of M&I Common Stock, which is to be issued to
Security shareholders in connection with the Merger, does not purport to be a
complete description of the applicable provisions of the M&I Articles and
Bylaws, as amended, or of applicable statutory or other law, and is qualified,
in its entirety by reference thereto.
 
  Voting. Each holder of M&I Common Stock is entitled at each shareholders'
meeting of M&I, as to each matter to be voted upon, to cast one vote, in
person or by proxy, for each share of M&I Common Stock registered in his or
her name on the stock transfer books of M&I, except to the extent that the
voting power of shares held by any person in excess of 20% of the voting power
in the election of directors may be limited (in voting on any matter) to one-
tenth of the full voting power of those shares under (S)180.1150 of the WBCL.
Such voting rights are not cumulative.
 
  Dividends. The holders of M&I Common Stock are entitled to receive
dividends, when and if declared by the Board of Directors of M&I out of any
funds legally available therefore after dividends have been paid to the
holders of the M&I Preferred Stock.
 
  Liquidation. Upon liquidation of M&I, the holders of M&I Common Stock are
entitled to receive the net assets of M&I after satisfaction in full of the
prior rights of creditors of M&I and holders of the M&I Preferred Stock.
 
  Miscellaneous. M&I Common Stock is not convertible into shares of any other
class of capital stock. Holders of M&I Common Stock are not and will not be
entitled to any preemptive rights. The issued and outstanding shares of M&I
Common Stock are fully paid and non-assessable (except as otherwise provided
under (S)180.0622(2)(b) of the WBCL).
 
M&I PREFERRED STOCK
 
  The M&I Preferred Stock is issuable in one or more series and, with respect
to any series, the M&I Board of Directors, subject to certain limitations, is
authorized to: (a) fix the number of shares; (b) designate any series and the
number of shares which shall constitute the series; (c) determine voting
rights; (d) determine dividend rates, payment dates and whether dividends
shall be cumulative; (e) determine the amount per share payable on the shares
of each series in the event of the liquidation or dissolution or winding up of
M&I; (f) determine any redemption provisions; (g) determine any sinking fund
provisions; (h) determine any conversion provisions; and (i) determine any
other terms, limitations and relative rights and preferences of the series as
may lawfully be determined by the Board of Directors and as shall not be
inconsistent with the M&I Articles and the WBCL.
 
  Shares of M&I Preferred Stock that are redeemed, repurchased or otherwise
acquired by M&I shall be returned and restored to the status of authorized,
unissued shares, but may be reissued only as a part of the M&I Preferred Stock
other than the series of which they were originally a part.
 
                                      54
<PAGE>
 
M&I SERIES A PREFERRED STOCK
 
  Voting. The holders of M&I Series A Preferred Stock only have voting rights
as provided by the WBCL, which generally occurs only if a proposed amendment
to the M&I Articles or a merger or share exchange would affect the M&I Series
A Preferred Stock.
 
  The WBCL provides that whenever an amendment shall affect the holders of
shares of one or more but not all the series of any preferred or special
class, at the time outstanding, the holders of the outstanding shares of the
series affected shall be deemed a separate class and entitled to vote as a
class on such amendment.
 
  Dividends. The holders of M&I Series A Preferred Stock are entitled to
receive cash dividends when and as cash dividends are declared and become
payable with respect to the M&I Common Stock equal to the amount of the cash
dividend that such holder would have received had such holder converted M&I
Series A Preferred Stock into M&I Common Stock. Dividends on M&I Series A
Preferred Stock are noncumulative. Holders of M&I Series A Preferred Stock are
not entitled to any other earnings of M&I, except for the preference, if any,
as may be payable in case of liquidation, dissolution or winding up.
 
  Liquidation. In the event of any liquidation, dissolution, or winding up of
M&I, the holders of the Series A Preferred Stock shall be entitled to receive
$100 per share plus an amount equal to all dividends, if any, which have
accrued thereon as the result of the declaration of dividends on the M&I
Common Stock but which remain unpaid to the date of distribution. If, upon any
liquidation, dissolution or winding up of M&I, the assets of M&I to be paid or
distributed to the holders of the shares of the M&I Preferred Stock shall be
insufficient to pay in full the M&I Series A Preferred Stock liquidation
preference and the liquidation preference of any other equally ranking series
of M&I Preferred Stock, then such assets shall be shared ratably by the
holders of M&I Series A Preferred Stock and such other series of M&I Preferred
Stock.
 
  Conversions. The holders of M&I Series A Preferred Stock have the right to
convert such shares into shares of M&I Common Stock at any time. Each share of
M&I Series A Preferred Stock shall be valued at $100 for the purposes of such
conversion. The price at which shares of M&I Common Stock shall be delivered
upon conversion is at the same ratio that the Common Stock was exchanged for
M&I Series A Preferred Stock.
 
CERTAIN PROVISIONS OF THE WISCONSIN BUSINESS CORPORATION LAW
 
  The WBCL provides that shareholders of Wisconsin domestic corporations are
personally liable, up to the par value of their shares ($1.00 per share in the
case of the M&I Common Stock), for all debts owed by the corporation to
employees for services performed but not exceeding six months' service in any
one case. While the WBCL specifies that such liability is limited to the par
value of the shares, par value has been interpreted by a Wisconsin court to
mean the consideration paid to the corporation for its shares.
 
  The WBCL prohibits a "business combination" (defined to include a merger,
share exchange or a disposition of 5% or more of the aggregate market value of
all assets or stock of the corporation) between a "resident domestic
corporation" and an "interested stockholder" (defined as the beneficial owner
of at least 10% of the voting power of the outstanding stock) for three years
following the stock acquisition date (i.e., the date the person became an
interested stockholder), unless the board of directors approves the business
combination or the purchase of stock by the interested stockholder before the
stock acquisition date. Business combinations after the three-year period
following the stock acquisition date are permitted only if (i) the Board of
Directors approved the acquisition of the stock prior to the stock acquisition
date; (ii) the business combination is approved by a majority of the
outstanding voting stock not beneficially owned by the interested stockholder;
or (iii) the consideration to be received by shareholders meets certain
requirements of the statute with respect to form and amount. M&I is a
"resident domestic corporation" within the meaning of the WBCL.
 
  Under the WBCL, the voting power of shares, including shares issuable upon
conversion of convertible securities or exercise of options or warrants, of an
"issuing public corporation" held by any person or persons acting as a group
in excess of 20% of the voting power in the election of directors is limited
(in voting on any
 
                                      55
<PAGE>
 
matter) to 10% of the full voting power of those excess shares. An issuing
public corporation is defined as a domestic corporation with (i) total assets
exceeding $1,000,000; (ii) a class of equity securities held of record by 500
or more persons; and (iii) at least 100 shareholders of record who have
unlimited voting rights and who reside in Wisconsin. This restriction does not
apply to shares acquired (a) under an agreement entered into before the
corporation was an "issuing public corporation," (b) directly from the issuing
public corporation, (c) in a merger or share exchange to which the issuing
public corporation is a party, (d) in certain specified non-market
transactions (i.e., gifts, distributions upon death and pledges), or (e) in a
transaction incident to which the corporation's shareholders have approved
restoration of the full voting power of the otherwise restricted shares. M&I
is an "issuing public company" within the meaning of the WBCL.
 
  The WBCL provides that, in addition to the vote otherwise required by law or
the articles of incorporation of an "issuing public corporation" (defined
above), the approval by a majority vote of the holders of the corporation's
shares entitled to vote is required before such corporation can take certain
actions while a "takeover offer" (as defined in the WBCL) is being made or
after a takeover offer has been publicly announced and before it is concluded.
Under the WBCL, such shareholder approval is required for the corporation to
(i) acquire more than 5% of the corporation's outstanding voting shares at a
price above the market price from any individual or organization that owns
more than 3% of the outstanding voting shares and has held such shares for
less than two years, unless a similar offer is made to acquire all voting
shares or (ii) sell or option assets of the corporation which amount to at
least 10% of the market value of the corporation, unless the corporation has
at least three independent directors and a majority of the independent
directors vote not to have this provision apply to the corporation.
 
  The WBCL also provides for certain super-majority voting and fair price
provisions in connection with certain business combinations substantially
similar to provisions contained in M&I's Articles. See "COMPARISON OF
SHAREHOLDER RIGHTS--Certain Business Combinations."
 
  Under the WBCL, 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 the corporation's shareholders, considering the effects of
the action on the employees, suppliers, customers, the communities in which
the corporation operates and any other factors that the director or officer
considers pertinent.
 
                       COMPARISON OF SHAREHOLDER RIGHTS
 
  The following is a summary of the material differences between the rights of
holders of M&I Common Stock and the rights of holders of Security Common Stock
prior to the Merger. As both M&I and Security are organized under the laws of
Wisconsin, rights of shareholders are substantially similar. Differences in
the rights provided to shareholders of M&I and Security arise from the
provisions of the Articles of Incorporation and Bylaws. This summary does not
purport to be a complete discussion of and is qualified in its entirety by
reference to the governing law and the Articles of Incorporation and Bylaws of
the respective companies.
 
AUTHORIZED CAPITAL STOCK
 
  M&I. The Restated Articles of Incorporation of Marshall & Ilsley Corporation
(the "M&I Articles") authorize the issuance of up to 165,000,000 shares of
capital stock, consisting of 160,000,000 shares of M&I Common Stock, par value
$1.00 per share, of which 88,639,389 shares were issued and outstanding as of
April 30, 1997, and up to 5,000,000 shares of M&I Preferred Stock. M&I
Preferred Stock is issuable in series, each having such rights and preferences
as the M&I Board may, by adoption of an amendment of the M&I Articles, fix and
determine. As of April 30, 1997, 685,314 shares of M&I Series A Preferred were
issued and outstanding. The availability of authorized shares for issuance
could render more difficult or discourage a merger, tender offer, proxy
contest or other attempt to obtain control of M&I. See "DESCRIPTION OF M&I
CAPITAL STOCK."
 
 
                                      56
<PAGE>
 
  Security. The Articles of Incorporation of Security Capital Corporation (the
"Security Articles") authorize the issuance of up to 60,000,000 shares of
capital stock, consisting of 50,000,000 shares of Security Common Stock, par
value $1.00 per share, of which 9,208,332 (including 112,700 shares held by
Security) shares were issued and outstanding as of May 31, 1997, and up to
10,000,000 shares of Preferred Stock, par value $1.00 per share (the "Security
Preferred Stock"), no shares of which were outstanding as of May 31, 1997.
 
REQUIRED VOTE
 
  M&I. Pursuant to (S)180.1706(1) of the WBCL, except as otherwise provided in
a corporation's articles of incorporation or by-laws, any amendment to the
articles of incorporation, merger or certain other extraordinary events
involving a corporation organized before January 1, 1973, which did not
expressly elect before January 1, 1991 to be governed by a majority or greater
voting requirement, must be approved by the affirmative vote of two-thirds of
the shares entitled to vote at a meeting called for that purpose. The M&I
Articles were amended prior to January 1, 1991 to reduce the vote required for
a merger, consolidation or certain other extraordinary events to a majority
vote of the M&I capital stock entitled to vote, provided that three-quarters of
the M&I Board of Directors shall have approved the transaction. The M&I
Articles were not amended prior to January 1, 1991 to reduce the vote required
to amend the M&I Articles. Consequently, any amendment to the M&I Articles
requires the affirmative vote of two-thirds of the outstanding shares of M&I
capital stock entitled to vote at a meeting called for that purpose. The
requirement that two-thirds of the outstanding shares of M&I capital stock
entitled to vote at a meeting to approve any amendment to the M&I Articles
could make it more difficult for any party seeking to take control of M&I
through a merger, tender offer, proxy contest, or otherwise to amend the M&I
Articles in furtherance of any such action, such as the repeal of provisions
classifying the M&I Board of Directors or permitting the removal of directors
other than for "cause."
 
  Security. Security was organized after January 1, 1973 and, thus, is not
subject to the voting requirements stated in (S)180.1706 of the WBCL. However,
the Security Articles state that except as may otherwise be provided by law,
the affirmative vote of eighty percent (80%) of the shares of Security capital
stock entitled to vote is required to amend or repeal Articles IV, V, VI, VII,
VIII, IX, X, XII or XIII of the Security Articles, which contain provisions,
among others, classifying the Security Board of Directors and permitting the
removal of directors only for "cause."
 
SIZE OF BOARD OF DIRECTORS
 
  M&I. The M&I Articles and Bylaws provide that the M&I Board of Directors will
consist of not less than three directors (exclusive of directors, if any,
elected by the holders of one or more classes or series of M&I Preferred Stock
pursuant to the M&I Articles applicable thereto), the number of which may be
established within such limits by resolution adopted by the affirmative vote of
a majority of the entire Board of Directors then in office; however, the Board
of Directors may not decrease the number if the term of any incumbent director
would thereby be effected.
 
  Security. The Security Articles and Bylaws provide that the Security Board
shall consist of not less than seven nor more than twenty members as determined
by the shareholders at each annual meeting. The Security shareholders or Board
of Directors may increase or decrease the number of directors from time to
time; however, the shareholders or Board of Directors may not decrease the
number if the term of any incumbent director would thereby be effected.
 
REMOVAL OF DIRECTORS FOR "CAUSE"
 
  M&I. Exclusive of directors, if any, elected by holders of one or more
classes of M&I Preferred Stock, shareholders of M&I may remove a director only
for "cause" and then only by a vote of two-thirds of the outstanding shares of
capital stock of M&I entitled to vote at a meeting of shareholders called for
that purpose. "Cause" is defined solely as malfeasance arising from the
performance of a director's duties which has a
 
                                       57
<PAGE>
 
materially adverse effect on the business of M&I. This provision could deter
or discourage a party seeking to obtain control of M&I by removing one or more
directors from the M&I Board of Directors.
 
  Security. A director may be removed from his position as director only for
"cause" and by (i) the affirmative vote of not less than 80% of the issued and
outstanding shares of capital stock of Security entitled to vote generally in
an election of directors, voting at a duly constituted meeting of shareholders
called for that purpose, or (ii) a majority of the total number of directors.
"Cause" is not defined in either the Security Articles or Security Bylaws. A
director elected by holders of one or more classes of Security Preferred
Stock, if any, may only be removed by an 80% vote of the issued and
outstanding shares of that class or series of Security Preferred Stock which
elected such director.
 
ADVANCE NOTICE OF PROPOSALS TO BE BROUGHT AT THE ANNUAL MEETING
 
  M&I. Pursuant to Section 2.5 of the M&I Bylaws, any shareholder who intends
to bring business before an annual meeting of shareholders must provide M&I
with notice of such intention, the nature of such proposal, the reasons for
conducting such business at the annual meeting and certain information
regarding the shareholder bringing the proposal not less than 90 days prior to
the anniversary date of the annual meeting of shareholders in the immediately
preceding year. This provision could render more difficult or discourage an
attempt to obtain control of M&I through a proposal brought before an annual
meeting of shareholders. M&I would have to be given advance notice of any such
proposal in accordance with the M&I Bylaws which notice to M&I may discourage
the making of such proposal.
 
  Security. Pursuant to Article VII of the Security Articles, any shareholder
who intends to bring any proposals for any business to be considered at any
annual or special meeting of the shareholders of Security must provide the
Secretary of Security with notice of such intention, the nature of such
proposal, the reasons for conducting such business at the meeting and certain
information regarding the shareholder making the proposal not later than the
tenth (10th) day following the day on which notice of the meeting was mailed
to shareholders.
 
ADVANCE NOTICE OF NOMINATIONS OF DIRECTORS
 
  M&I. Pursuant to Article VI of the M&I Articles and Section 2.6 of the M&I
Bylaws, any shareholder who intends to nominate directors for election at a
meeting called for that purpose must provide M&I with notice of such
intention, a written consent of the nominee to serve as a director, certain
information regarding the proposed nominee and certain information regarding
the nominating shareholder not less than 90 days prior to the anniversary date
of the annual meeting of shareholders in the immediately preceding year. This
provision could deter or discourage a party seeking to obtain control of M&I
by electing directors to the M&I Board of Directors. Any such party would be
required to comply with the M&I Articles and M&I Bylaws in nominating
directors to the M&I Board of Directors and such compliance could deter or
discourage such party from nominating directors to the M&I Board of Directors.
 
  Security. Pursuant to Article VII of the Security Articles, any shareholder
who intends to nominate directors at any annual or special meeting of the
shareholders of Security must provide the Secretary of Security with notice of
such intention, a written consent of the nominee to serve as a director,
certain information regarding the proposed nominee and certain information
regarding the nominating shareholder not later than the tenth (10th) day
following the day on which notice of the meeting was mailed to shareholders.
 
CERTAIN BUSINESS COMBINATIONS
 
  M&I. Article XI of M&I's Articles provides that an affirmative vote of 80%
of M&I's outstanding capital stock entitled to vote in the election of
directors, or two-thirds of the shares entitled to so vote excluding shares of
M&I capital stock held by an "interested stockholder" (as hereinafter
defined), is required to approve a merger or other business combination
involving M&I, or any subsidiary, and any interested shareholder or an
affiliate or associate of an interested shareholder (excluding M&I or any
subsidiary thereof or employee benefit plan for the benefit of employees of
M&I or its subsidiaries).
 
                                      58
<PAGE>
 
  An interested shareholder refers to (a) the beneficial owner of more than 10%
of M&I's outstanding capital stock entitled to vote in the election of
directors, (b) an affiliate or associate of M&I that at any time within the
two-year period preceding the combination was a beneficial owner of 10% or more
of the outstanding M&I capital stock entitled to vote in the election of
directors or (c) an assignee of or successor to any M&I capital stock entitled
to vote in the election of directors previously beneficially owned within the
two year period preceding the combination by another interested shareholder, if
such assignment or succession occurred involved a transaction not involving a
public offering within the meaning of the Securities Act.
 
  These provisions of the M&I Articles do not apply if (a) the consideration
offered in connection with such transaction satisfies certain "fair price"
requirements or (b) a majority of the "disinterested directors" (defined as a
director who is not affiliated with the interested shareholder and who either
was (i) a member of the Board of Directors prior to the date that the
interested shareholder became such or (ii) elected or recommended for election
by a majority of the disinterested directors in office at the time such
director was nominated for election) approves the transaction. The
supermajority voting provisions could deter or discourage an "interested
stockholder" from proposing or pursuing a business combination with M&I.
 
  Security. Article X of the Security Articles state that Security elects to be
subject to the provisions of Sections 180.1130 through 180.1134 of the WBCL,
which contain business combinations provisions substantially similar to the
provisions in M&I's Articles. In addition, the Security Articles state that any
business combination, as defined in Section 180.1130 of the WBCL, must be
approved by a majority of the disinterested directors.
 
  Article IV of the Security Articles provides that if any person acquires
direct or indirect beneficial ownership of more than ten percent (10%) of the
then outstanding shares of Security common stock, any shares beneficially owned
in excess of ten percent (10%) shall not be counted as shares entitled to vote,
shall not be counted as voting shares in connection with any matter submitted
to shareholders for a vote, and shall not be counted as outstanding for
purposes of determining a quorum or the affirmative vote necessary to approve
any matter submitted to the shareholders for a vote. The voting restrictions
contained in Article IV do not apply to an acquisition of more than ten percent
(10%) of the shares of common stock if the acquisition is approved by a
majority of disinterested directors and if such approval was given at a meeting
where a quorum of disinterested directors was present. In addition, Security
expressly elects to be subject to (S)180.1150 of the WBCL, which contains
similar control share voting restrictions with respect to acquisitions of more
than twenty percent (20%) of the voting power in the election of directors. As
a Wisconsin corporation, M&I also is subject to (S)180.1150 of the WBCL.
 
                CERTAIN INFORMATION CONCERNING M&I AND SECURITY
 
  Information regarding the names, ages, positions and business backgrounds of
the executive officers and directors of M&I and Security, respectively, as well
as additional information, including executive compensation, security ownership
of certain beneficial owners and management and certain relationships and
related transactions, is incorporated herein by reference to (i) M&I's Annual
Report on Form 10-K for the year ended December 31, 1996, which incorporates
portions of its Proxy Statement for the 1997 Annual Meeting of Shareholders and
(ii) Security's Annual Report on Form 10-K for the year ended June 30, 1996,
which incorporates portions of its Proxy Statement for the 1996 Annual Meeting
of Shareholders.
 
                                    EXPERTS
 
  The financial statements of Security Capital Corporation as of June 30, 1996
and 1995, and for each of the years in the three-year period ended June 30,
1996, have been incorporated by reference herein and in the registration
statement in reliance upon the report of KPMG Peat Marwick LLP, independent
certified public accountants, incorporated by reference herein, and upon the
authority of said firm as experts in accounting and auditing.
 
                                       59
<PAGE>
 
  The financial statements of Marshall & Ilsley Corporation and subsidiaries
as of December 31, 1996 and 1995, and for each of the years in the three-year
period ended December 31, 1996, have been incorporated by reference herein and
in the registration statement in reliance upon the report of Arthur Andersen
LLP, independent public accountants, incorporated by reference herein and upon
authority of said firm as experts in accounting and auditing.
 
                                 LEGAL MATTERS
 
  The validity of the M&I Common Stock to be issued in connection with the
Merger will be passed upon for M&I by Godfrey & Kahn, S.C., Milwaukee,
Wisconsin.
 
                             SHAREHOLDER PROPOSALS
 
  The 1998 Annual Meeting of M&I's Shareholders is scheduled for April 28,
1998. In accordance with M&I's Bylaws, nominations, other than by or at the
direction of the Board of Directors, of candidates for election as directors
at the 1998 Annual Meeting of Shareholders and any other shareholder proposed
business to be brought before the 1998 Annual Meeting of Shareholders must be
submitted to M&I not later than January 22, 1998. Shareholder proposed
nominations and other shareholder proposed business must be made in accordance
with M&I's Bylaws which provide, among other things, that shareholder proposed
nominations must be accompanied by certain information concerning the nominee
and the shareholder submitting the nomination, and that shareholder proposed
business must be accompanied by certain information concerning the proposal
and the shareholder submitting the proposal.
 
  To be considered for inclusion in the proxy statement solicited by the Board
of Directors, shareholder proposals for consideration at the 1998 Annual
Meeting of Shareholders of M&I must be received by M&I at its principal
executive offices, 770 North Water Street, Milwaukee, Wisconsin 53202 on or
before November 7, 1997. Proposals should be directed to Mr. M.A. Hatfield,
Senior Vice President and Secretary. To avoid disputes as to the date of
receipt, it is suggested that any shareholder proposals be submitted by
certified mail, return receipt requested.
 
                                      60
<PAGE>
 
                                                                      APPENDIX A
 
 
                          AGREEMENT AND PLAN OF MERGER
 
                                 BY AND BETWEEN
 
                          SECURITY CAPITAL CORPORATION
 
                                      AND
 
                         MARSHALL & ILSLEY CORPORATION
 
                           DATED AS OF MARCH 14, 1997
 
 
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                                           PAGE
                                                                           ----
 <C>              <S>                                                      <C>
 ARTICLE I--THE MERGER
    Section 1.1   The Merger.............................................    1
    Section 1.2   Effective Time.........................................    1
    Section 1.3   Effect of the Merger...................................    2
    Section 1.4   Articles of Incorporation; By-Laws.....................    2
    Section 1.5   Directors and Officers.................................    2
    Section 1.6   Conversion of Securities...............................    2
    Section 1.7   Election Procedures....................................    4
    Section 1.8   Adjustments for Dilution and Other Matters.............    6
    Section 1.9   Exchange of Certificates...............................    6
    Section 1.10  Stock Transfer Books...................................    9
    Section 1.11  Company Common Stock...................................    9
 ARTICLE II--REPRESENTATIONS AND WARRANTIES OF SELLER
    Section 2.1   Organization and Qualification; Subsidiaries...........    9
    Section 2.2   Articles of Incorporation and By-Laws..................   11
    Section 2.3   Capitalization.........................................   11
    Section 2.4   Authority..............................................   12
    Section 2.5   No Conflict; Required Filings and Consents.............   12
    Section 2.6   Compliance; Permits....................................   13
    Section 2.7   Securities and Banking Reports; Financial Statements...   13
    Section 2.8   Absence of Certain Changes or Events...................   14
    Section 2.9   Absence of Litigation..................................   15
    Section 2.10  Employee Benefit Plans.................................   15
    Section 2.11  Registration Statement; Proxy Statement/Prospectus.....   18
    Section 2.12  Title to Property......................................   19
    Section 2.13  Environmental Matters..................................   19
    Section 2.14  Absence of Agreements..................................   20
    Section 2.15  Taxes..................................................   21
    Section 2.16  Insurance..............................................   21
    Section 2.17  Brokers................................................   22
    Section 2.18  Tax Matters............................................   22
    Section 2.19  Material Adverse Effect................................   22
    Section 2.20  Material Contracts.....................................   22
    Section 2.21  Opinion of Financial Advisor...........................   22
    Section 2.22  Vote Required..........................................   22
    Section 2.23  Options; Employment Agreements.........................   23
 ARTICLE III--REPRESENTATIONS AND WARRANTIES OF THE COMPANY
    Section 3.1   Organization and Qualification; Subsidiaries...........   23
    Section 3.2   Articles of Incorporation and By-Laws..................   24
    Section 3.3   Capitalization.........................................   24
    Section 3.4   Authority..............................................   25
    Section 3.5   No Conflict; Required Filings and Consents.............   25
    Section 3.6   Compliance; Permits....................................   26
    Section 3.7   Securities and Banking Reports; Financial Statements...   26
    Section 3.8   Absence of Certain Changes or Events...................   27
    Section 3.9   Absence of Litigation..................................   28
    Section 3.10  Employee Benefit Plans.................................   28
    Section 3.11  Registration Statement; Proxy Statement/Prospectus.....   29
</TABLE>
 
                                       i
<PAGE>
 
<TABLE>
<CAPTION>
                                                                          PAGE
                                                                          ----
 <C>              <S>                                                     <C>
    Section 3.12  Title to Property.....................................   30
    Section 3.13  Absence of Agreements.................................   30
    Section 3.14  Taxes.................................................   30
    Section 3.15  Brokers...............................................   31
    Section 3.16  Tax Matters...........................................   31
    Section 3.17  Material Adverse Effect...............................   31
 ARTICLE IV--COVENANTS OF SELLER
    Section 4.1   Affirmative Covenants.................................   32
    Section 4.2   Negative Covenants....................................   32
    Section 4.3   Letter of Seller's Accountants........................   35
    Section 4.4   Access and Information................................   36
    Section 4.5   Update Disclosure; Breaches...........................   36
    Section 4.6   Affiliates; Tax Treatment.............................   37
    Section 4.7   Expenses..............................................   37
    Section 4.8   Delivery of Shareholder List..........................   38
    Section 4.9   Loan and Investment Policies..........................   38
 ARTICLE V--COVENANTS OF THE COMPANY
    Section 5.1   Affirmative Covenants.................................   38
    Section 5.2   Negative Covenants....................................   39
    Section 5.3   Access and Information................................   39
    Section 5.4   Breaches..............................................   40
    Section 5.5   Stock Exchange Listing................................   40
    Section 5.6   Tax Treatment.........................................   40
    Section 5.7   Stock Options.........................................   40
 ARTICLE VI--ADDITIONAL AGREEMENTS
    Section 6.1   Proxy Statement/Prospectus; Registration Statement....   41
    Section 6.2   Meeting of Seller's Shareholders......................   41
    Section 6.3   Appropriate Action; Consents; Filings.................   42
                  Employee Stock Options and Other Employee Benefit
    Section 6.4    Matters..............................................   42
                  Directors' and Officers' Indemnification and
    Section 6.5    Insurance............................................   42
    Section 6.6   Notification of Certain Matters.......................   44
    Section 6.7   Public Announcements..................................   44
    Section 6.8   Customer Retention....................................   44
    Section 6.9   Data Services Conversion..............................   45
    Section 6.10  Incentive Bonus Pool..................................   45
    Section 6.11  Seller Share Purchases................................   45
 ARTICLE VII--CONDITIONS OF MERGER
                  Conditions to Obligation of Each Party to Effect the
    Section 7.1    Merger...............................................   46
    Section 7.2   Additional Conditions to Obligations of the Company...   46
    Section 7.3   Additional Conditions to Obligations of Seller........   48
 ARTICLE VIII--INDUCEMENT
    Section 8.1   Inducement............................................   49
 ARTICLE IX--TERMINATION, AMENDMENT AND WAIVER
    Section 9.1   Termination...........................................   51
    Section 9.2   Effect of Termination.................................   54
    Section 9.3   Amendment.............................................   54
    Section 9.4   Waiver................................................   55
</TABLE>
 
 
                                       ii
<PAGE>
 
<TABLE>
<CAPTION>
                                                                         PAGE
                                                                        ------
 <C>              <S>                                                   <C>
 ARTICLE X--GENERAL PROVISIONS
                  Non-Survival of Representations, Warranties and
    Section 10.1   Agreements.........................................      55
                  Non-Survival of Representations, Warranties and
    Section 10.2   Agreements.........................................      55
    Section 10.3  Notices.............................................      55
    Section 10.4  Certain Definitions.................................      56
    Section 10.5  Headings............................................      57
    Section 10.6  Severability........................................      57
    Section 10.7  Entire Agreement....................................      58
    Section 10.8  Assignment..........................................      58
    Section 10.9  Parties in Interest.................................      58
    Section 10.10 Governing Law.......................................      58
    Section 10.11 Counterparts........................................      58
 ANNEX A--SUBSIDIARIES OF SELLER.......................................    A-1
 ANNEX B--EMPLOYEE STOCK OPTIONS AND OTHER EMPLOYEE BENEFIT MATTERS....    B-1
 EXHIBIT 2.23.......................................................... 2.23.1
 EXHIBIT 9.1--INDEX GROUP..............................................  9.1-1
</TABLE>
 
                                      iii
<PAGE>
 
                             INDEX OF DEFINED TERMS
 
<TABLE>
<CAPTION>
                                                                  SECTION
                                                                  -------
<S>                                                          <C>
Acquisition Event...........................................    Section 8.1(c)
Acquisition Proposal........................................    Section 8.1(d)
affiliate...................................................   Section 10.4(a)
Aggregate Consideration.....................................    Section 1.6(b)
Agreement...................................................      Preamble
Articles of Merger..........................................     Section 1.2
Average Per Share Consideration.............................    Section 1.6(b)
Bank Merger.................................................      Preamble
Bank Merger Agreement.......................................    Section 4.1(f)
beneficial owner............................................   Section 10.4(b)
BHCA........................................................    Section 2.1(a)
Blue Sky Laws...............................................    Section 2.5(b)
Bonus Pool..................................................    Section 6.10
business day................................................   Section 10.4(c)
                                                               Section
Cash Designated Shares......................................   1.7(b)(ii)
Cash Election Shares........................................     Section 1.7
Certificates................................................     Section 1.7
Claim.......................................................    Section 6.5(a)
Code........................................................      Preamble
Company.....................................................      Preamble
Company Approvals...........................................    Section 3.1(a)
Company Articles............................................     Section 1.4
                                                             Section
Company Average Price....................................... 9.1(a)(vii)(A)
Company By-Laws.............................................     Section 1.4
Company Common Stock........................................  Section 1.6(a)(A)
Company Disclosure Schedule.................................     Article III
Company Lead Bank...........................................      Preamble
Company Plans...............................................   Section 3.10(a)
Company Preferred Stock.....................................    Section 3.3(a)
Company Reports.............................................    Section 3.7(a)
Company SEC Reports.........................................    Section 3.7(a)
Company Subsidiaries........................................    Section 3.1(a)
Company Subsidiary..........................................    Section 3.1(a)
control.....................................................   Section 10.4(d)
Data Processing Conversion..................................     Section 1.2
DFI.........................................................    Section 2.1(a)
Division of Savings Institutions............................    Section 2.1(a)
Effective Time..............................................     Section 1.2
Election Deadline...........................................     Section 1.7
Election Form Record Date...................................     Section 1.7
Election Forms..............................................     Section 1.7
Environmental Claims........................................    Section 2.13
Environmental Laws..........................................    Section 2.13
ERISA.......................................................   Section 2.10(a)
Exchange Act................................................    Section 2.5(b)
Exchange Agent..............................................     Section 1.7
Exchange Fund...............................................    Section 1.9(a)
</TABLE>
 
                                       iv
<PAGE>
 
<TABLE>
<CAPTION>
                                                                   SECTION
                                                                   -------
<S>                                                          <C>
Exhibit 21..................................................     Section 3.1(c)
Expenses....................................................     Section 4.7(b)
FDIC........................................................     Section 2.1(a)
                                                             Section
Final Index Price........................................... 9.1(a)(vii)(C)(4)
                                                             Section
Final Price................................................. 9.1(a)(vii)(C)(3)
Governmental Authority......................................     Section 2.13
Indemnified Parties.........................................     Section 6.5(a)
Indemnified Party...........................................     Section 6.5(d)
                                                             Section
Index Group................................................. 9.1(a)(vii)(C)(1)
                                                             Section
Initial Index Price......................................... 9.1(a)(vii)(C)(2)
Insurance Amount............................................     Section 6.5(b)
IRS.........................................................     Section 2.15
ISO.........................................................    Section 2.10(h)
Laws........................................................     Section 2.5(a)
Loan Property...............................................     Section 2.13
Mailing Date................................................      Section 1.7
Material Adverse Effect.....................................     Section 2.1(d)
Merger......................................................       Preamble
Mixed Election Shares.......................................      Section 1.7
NASDAQ......................................................      Section 1.6
NASDAQ/NMS..................................................     Section 1.6(b)
No Election Shares..........................................      Section 1.7
Nullifying Event............................................     Section 8.1(e)
Option Exercise Agreement...................................     Section 2.23
Option Plans................................................      Section 5.7
Participation Facility......................................     Section 2.13
Per Share Stock Consideration...............................     Section 1.6(b)
person......................................................    Section 10.4(e)
Plans.......................................................    Section 2.10(a)
Proxy Statement/Prospectus..................................     Section 2.11
Registration Statement......................................     Section 3.11
SEC.........................................................     Section 2.7(a)
Section 180.0622(2)(b) of the WBCL..........................      Section 2.3
Securities Act..............................................     Section 2.5(b)
Seller......................................................       Preamble
Seller Affiliate............................................      Section 4.6
Seller Approvals............................................     Section 2.1(a)
Seller Articles.............................................      Section 2.2
Seller By-Laws..............................................      Section 2.2
Seller Common Stock.........................................     Section 1.6(a)
Seller Disclosure Schedule..................................       Article II
Seller Option...............................................      Section 5.7
Seller Preferred Stock......................................      Section 2.3
Seller Reports..............................................     Section 2.7(a)
Seller SEC Reports..........................................     Section 2.7(a)
</TABLE>
 
                                       v
<PAGE>
 
<TABLE>
<CAPTION>
                                                                     SECTION
                                                                     -------
<S>                                                               <C>
Seller Shareholders' Meeting.....................................  Section 2.11
                                                                   Section
Seller Subsidiaries..............................................  2.1(a)
                                                                   Section
Seller Subsidiary................................................  2.1(a)
Seller's Bank....................................................    Preamble
                                                                   Section
Series A Preferred Stock.........................................  3.3(a)
                                                                   Section
Significant Subsidiary...........................................  8.1(f)
Stock Amount.....................................................   Section 1.6
                                                                  Section
Stock Designated Shares.......................................... 1.7(a)(ii)
Stock Election Shares............................................   Section 1.7
                                                                  Section
subsidiaries..................................................... 10.4(f)
                                                                  Section
subsidiary....................................................... 10.4(f)
Surviving Corporation............................................   Section 1.1
                                                                   Section
takeover proposal................................................  4.2(e)
Tax..............................................................  Section 2.15
Tax Returns......................................................  Section 2.15
Taxes............................................................  Section 2.15
                                                                  Section
Title IV Plan.................................................... 2.10(b)
                                                                   Section
Trigger Event....................................................  8.1(b)
Valuation Period.................................................   Section 1.6
                                                                   Section
Valuation Period Market Value....................................  1.6(b)
                                                                   Section
Valuation Period Share Number....................................  1.6(b)
WBCL.............................................................    Preamble
                                                                   Section
WBL..............................................................  2.5(b)
</TABLE>
 
                                       vi
<PAGE>
 
                         AGREEMENT AND PLAN OF MERGER
 
  Agreement and Plan of Merger, dated as of March 14, 1997 (the "Agreement")
between Security Capital Corporation, a Wisconsin corporation (the "Seller")
and Marshall & Ilsley Corporation, a Wisconsin corporation (the "Company").
 
  Whereas, the Boards of Directors of the Company and the Seller have each
determined that it is fair to and in the best interests of their respective
shareholders for the Seller to merge with and into the Company (the "Merger")
upon the terms and subject to the conditions set forth herein and in
accordance with the Wisconsin Business Corporation Law (the "WBCL");
 
  Whereas, the respective Boards of Directors of the Company and the Seller
have each approved the Merger of the Seller with and into the Company, upon
the terms and subject to the conditions set forth herein, and adopted this
Agreement;
 
  Whereas, for federal income tax purposes, it is intended that the Merger
shall qualify as a reorganization under the provisions of Section 368 of the
Internal Revenue Code of 1986, as amended (the "Code"); and
 
  Whereas, immediately following with the Merger, the parties intend to
consummate a merger of Seller's bank subsidiary ("Seller's Bank") with and
into Company's lead bank ("Company Lead Bank") (the "Bank Merger");
 
  Now, Therefore, in consideration of the foregoing premises and the
representations, warranties and agreements contained herein, and subject to
the terms and conditions set forth herein, the parties hereto hereby agree as
follows:
 
                             ARTICLE I--THE MERGER
 
  Section 1.1 The Merger. Upon the terms and subject to the conditions set
forth in this Agreement, and in accordance with the WBCL, at the Effective
Time (as defined in Section 1.2) Seller shall be merged with and into the
Company. As a result of the Merger, the separate corporate existence of Seller
shall cease and the Company shall continue as the surviving corporation of the
Merger (the "Surviving Corporation").
 
  Section 1.2 Effective Time. As promptly as practicable after the
satisfaction or, if permissible, waiver of the conditions set forth in Article
VII, but in no event prior to the earlier of (i) as soon as practicable
following the completion of the conversion of Seller's bank offices to the
Company's data processing systems, including any and all testing related to
such conversion (the "Data Processing Conversion"), or (ii) October 1, 1997,
the parties hereto shall cause the Merger to be consummated by filing articles
of merger (the "Articles of Merger") with the Department of Financial
Institutions of the State of Wisconsin, in such form as required by, and
executed in accordance with the relevant provisions of, the WBCL (the date and
time of such filing is referred to herein as the "Effective Time").
 
  Section 1.3 Effect of the Merger. At the Effective Time, the effect of the
Merger shall be as provided in this Agreement and the applicable provisions of
the WBCL. Without limiting the generality of the foregoing, and subject
thereto, at the Effective Time, except as otherwise provided herein, all the
property, rights, privileges, powers and franchises of the Company and the
Seller shall vest in the Surviving Corporation, and all debts, liabilities and
duties of the Company and the Seller shall become the debts, liabilities and
duties of the Surviving Corporation.
 
  Section 1.4 Articles of Incorporation; By-Laws. At the Effective Time, the
Articles of Incorporation (the "Company Articles") and the By-Laws ("Company
By-Laws") of the Company, as in effect immediately prior to the Effective
Time, shall be the Articles of Incorporation and the By-Laws of the Surviving
Corporation.
 
 
                                      A-1
<PAGE>
 
  Section 1.5 Directors and Officers. At the Effective Time, the directors of
the Company immediately prior to the Effective Time shall be the initial
directors of the Surviving Corporation, each to hold office in accordance with
the Articles of Incorporation and By-Laws of the Surviving Corporation. At the
Effective Time, the officers of the Company immediately prior to the Effective
Time shall be the initial officers of the Surviving Corporation, in each case
until their respective successors are duly elected or appointed.
 
  Section 1.6 Conversion of Securities. At the Effective Time, by virtue of
the Merger and without any action on the part of Company, Seller or the holder
of the following securities:
 
    (a) Each share of the common stock, par value $1.00 per share of Seller
  ("Seller Common Stock"), issued and outstanding immediately prior to the
  Effective Time (including shares held by the Company or any Company
  Subsidiary) shall cease to be outstanding and shall be converted into and
  become the right to receive, at the election of the holder thereof as
  provided in Section 1.7, either:
 
      (A) that number of shares of common stock par value $1.00 per share
    of Company ("Company Common Stock") which is equal to the Per Share
    Stock Consideration, or
 
      (B) cash in an amount equal to the Average Per Share Consideration
 
  provided that, the aggregate number of shares of Company Common Stock that
  shall be issued in the Merger shall be equal to or nearly equal to
  12,327,390 (the "Stock Amount").
 
    (b) Each share of Seller Common Stock held as treasury stock shall be
  canceled.
 
    (c) For purposes of this Agreement the following definitions shall apply:
 
      "Average Per Share Consideration" shall mean the Aggregate
    Consideration divided by the Valuation Period Share Number (rounded to
    the nearest cent).
 
      "Aggregate Consideration" shall mean the sum of (x) the product of
    the Stock Amount and Valuation Period Market Value and (y)
    $376,335,605.
 
      "Cash Percentage" shall mean $376,335,605 divided by the Aggregate
    Consideration.
 
      "Per Share Stock Consideration" shall equal the Average Per Share
    Consideration divided by the Valuation Period Market Value.
 
      "Stock Percentage" shall mean (x) the product of the Stock Amount and
    the Valuation Period Market Value, divided by (y) the Aggregate
    Consideration.
 
      "Valuation Period Share Number" shall mean the total number of shares
    of Seller Common Stock issued and outstanding (excluding treasury
    shares or restricted shares under employee benefit plans which have not
    been awarded) on the last day of the Valuation Period.
 
      "Valuation Period Market Value" shall mean the average of the average
    final bid and asked quotations for the Company Common Stock as reported
    on the National Association of Securities Dealers Automated
    Quotation/National Market System ("NASDAQ/NMS") (as reported in The
    Wall Street Journal, Midwest edition, or, in the absence thereof, by
    another authoritative source) during the Valuation Period.
 
      "Valuation Period" shall mean the ten (10) consecutive trading-day
    period during which the shares of Company Common Stock are traded on
    the Nasdaq Stock Market National Market System ("NASDAQ") ending on the
    fifth calendar day immediately prior to the Effective Time.
 
  Section 1.7. Election Procedures. Election forms and other appropriate and
customary transmittal materials (which shall specify that delivery shall be
effected, and risk of loss and title to the certificates theretofore
representing Seller Common Stock ("Certificates") shall pass, only upon proper
delivery of such Certificates to a bank or trust company designated by Company
and reasonably satisfactory to Seller (the "Exchange Agent")) in such form as
Company and Seller shall mutually agree ("Election Forms") shall be mailed 30
days prior to the anticipated Effective Time or on such other earlier date as
Seller and Company shall mutually agree ("Mailing Date") to each holder of
record of Seller Common Stock as of five business days prior to the Mailing
Date ("Election Form Record Date").
 
                                      A-2
<PAGE>
 
  Each Election Form shall permit the holder (or the beneficial owner through
appropriate and customary documentation and instructions) either (i) to elect
to receive only Company Common Stock with respect to such holder's Seller
Common Stock ("Stock Election Shares"); (ii) to elect to receive only cash
with respect to such holder's Seller Common Stock ("Cash Election Shares");
(iii) to elect to receive Company Common Stock and cash in the proportion
described in subparagraph (a) below with respect to such holder's Seller
Common Stock ("Mixed Election Shares"); or (iv) to indicate that such holder
makes no election ("No Election Shares").
 
  Any Seller Common Stock with respect to which the holder (or the beneficial
owner, as the case may be) shall not have submitted to the Exchange Agent an
effective, properly completed Election Form on or before 5:00 p.m., New York
City time, on the 25th day following the Mailing Date (or such other time and
date as Company and Seller may mutually agree) (the "Election Deadline") shall
also be deemed to be "No Election Shares."
 
  Company shall make available up to two separate Election Forms, or such
additional Election Forms as the Company in its sole discretion may permit, to
all persons who become holders (or beneficial owners) of Seller Common Stock
between the Election Form Record Date and close of business on the business
day prior to the Election Deadline, and Seller shall provide to the Exchange
Agent all information reasonably necessary for it to perform as specified
herein.
 
  Any such election shall have been properly made only if the Exchange Agent
shall have actually received a properly completed Election Form by the
Election Deadline. An Election Form shall be deemed properly completed only if
accompanied by one or more Certificates (or customary affidavits and
indemnification regarding the loss or destruction of such Certificates or the
guaranteed delivery of such Certificates) representing all shares of Seller
Common Stock covered by such Election Form, together with duly executed
transmittal materials included in the Election Form. Any Election Form may be
revoked or changed by the person submitting such Election Form at or prior to
the Election Deadline. In the event an Election Form is revoked prior to the
Election Deadline, the shares of Seller Common Stock represented by such
Election Form shall become No Election Shares and Company shall cause the
Certificates to be promptly returned without charge to the person submitting
the Election Form upon written request to that effect from the person who
submitted the Election Form. Subject to the terms of this Agreement and of the
Election Form, the Exchange Agent shall have reasonable discretion to
determine whether any election, revocation or change has been properly or
timely made and to disregard immaterial defects in the Election Forms, and any
good faith decisions of the Exchange Agent regarding such matters shall be
binding and conclusive. Neither Company nor the Exchange Agent shall be under
any obligation to notify any person of any defect in an Election Form.
 
  Within five business days after the Election Deadline, unless the Effective
Time has not yet occurred, in which case as soon thereafter as practicable,
Company shall cause the Exchange Agent to effect the allocation among the
holders of Seller Common Stock of rights to receive Company Common Stock or
cash in the Merger in accordance with the Election Forms as follows:
 
    (a) Mixed Elections. Each of the Mixed Election Shares shall be converted
  into a right to receive a number of shares of Company Common Stock equal to
  the Per Share Stock Consideration multiplied by the Stock Percentage and
  cash equal to the Average Per Share Consideration multiplied by the Cash
  Percentage.
 
    (b) Stock Elections And Mixed Elections Less Than Stock Amount. If the
  number of shares of Company Common Stock that would be issued upon
  conversion in the Merger of the Stock Election Shares and the Mixed
  Election Shares is less than the Stock Amount, then:
 
      (i) each of the Stock Election Shares shall be converted into the
    right to receive a number of shares of Company Common Stock equal to
    the Per Share Stock Consideration,
 
      (ii) the Exchange Agent shall then select first from among the No
    Election Shares and then (if necessary) from among the Cash Election
    Shares, by a pro rata selection process, a sufficient number of shares
    ("Stock Designated Shares") such that the number of shares of Company
    Common Stock
 
                                      A-3
<PAGE>
 
    that will be issued in the Merger equals as closely as practicable the
    Stock Amount, and each of the Stock Designated Shares shall be
    converted into the right to receive a number of shares of Company
    Common Stock equal to the Per Share Stock Consideration, and
 
      (iii) each of the Cash Election Shares and the No Election Shares
    which are not Stock Designated Shares shall be converted into the right
    to receive cash equal to the Average Per Share Consideration.
 
    (c) Stock Elections and Mixed Elections More Than Stock Amount. If the
  number of shares of Company Common Stock that would be issued upon the
  conversion in the Merger of the Stock Election Shares and the Mixed
  Election Shares is greater than the Stock Amount, then:
 
      (i) each of the Cash Election Shares and No Election Shares shall be
    converted into the right to receive cash equal to the Average Per Share
    Consideration,
 
      (ii) the Exchange Agent shall then select from among the Stock
    Election Shares, by a pro rata selection process a sufficient number of
    shares ("Cash Designated Shares") such that the number of shares of
    Company Common Stock that will be issued in the Merger equals as
    closely as practicable the Stock Amount, and each of the Cash
    Designated Shares shall be converted into the right to receive cash
    equal to the Average Per Share Consideration, and
 
      (iii) each of the Stock Election Shares which are not Cash Designated
    Shares shall be converted into the right to receive a number of shares
    of Company Common Stock equal to the Per Share Stock Consideration.
 
  The pro rata selection process to be used by the Exchange Agent shall
consist of such equitable pro ration processes as shall be mutually determined
by Company and Seller.
 
  Section 1.8. Adjustments for Dilution and Other Matters. If prior to the
Effective Time, (i) Seller shall declare a stock dividend or distribution upon
or subdivide, split up, reclassify or combine the Seller Common Stock, or
declare a dividend or make a distribution on the Seller Common Stock in any
security convertible into Seller Common Stock, or (ii) Company shall declare a
stock dividend or distribution upon or subdivide, split up, reclassify or
combine the Company Common Stock or declare a dividend or make a distribution
on the Company Common Stock in any security convertible into Company Common
Stock, appropriate adjustment or adjustments will be made to the Per Share
Cash Consideration, the Per Share Stock Consideration and the Stock Amount.
 
  Section 1.9 Exchange of Certificates.
 
    (a) Exchange Agent. As of the Effective Time, the Company shall deposit,
  or shall cause to be deposited with the Exchange Agent, for the benefit of
  the holders of Shares, for exchange in accordance with this Article I,
  through the Exchange Agent, the amount of cash payable in the Merger and
  certificates representing the shares of Company Common Stock (such
  certificates for shares of Company Common Stock, together with the amount
  of cash payable in the Merger and any dividends or distributions with
  respect to such Company Common Stock are referred to herein as the
  "Exchange Fund") payable and issuable pursuant to Section 1.6 in exchange
  for outstanding Shares.
 
    (b) Exchange Procedures. As soon as reasonably practicable after the
  Effective Time, the Exchange Agent shall mail to each holder of record of a
  Certificate or Certificates which immediately prior to the Effective Time
  represented outstanding Shares whose Shares were converted into the right
  to receive shares of Company Common Stock or cash or both pursuant to
  Section 1.6, (i) a letter of transmittal (which shall specify that delivery
  shall be effected, and risk of loss and title to the Certificates shall
  pass, only upon delivery of the Certificates to the Exchange Agent and
  shall be in such form and have such other provisions as the Company may
  reasonably specify) and (ii) instructions for use in effecting the
  surrender of the Certificates in exchange for certificates representing
  shares of Company Common Stock or cash or both. Upon surrender of a
  Certificate for cancellation to the Exchange Agent together with such
  letter of transmittal, duly executed, the holder of such Certificate shall
  be entitled to receive in exchange therefor a certificate representing that
  number of whole shares of Company Common Stock or cash or both which such
  holder has the right to receive in respect of the Certificate surrendered
  pursuant to the provisions of
 
                                      A-4
<PAGE>
 
  this Article I (after taking into account all Shares then held by such
  holder), and the Certificate so surrendered shall forthwith be canceled. In
  the event of a transfer of ownership of Shares which is not registered in
  the transfer records of the Seller, a certificate representing the proper
  number of shares of Company Common Stock or cash or both may be issued to a
  transferee if the Certificate representing such Shares is presented to the
  Exchange Agent, accompanied by all documents required to evidence and
  effect such transfer and by evidence that any applicable stock transfer
  taxes have been paid. In the event any Certificate shall have been lost,
  stolen or destroyed, upon the making of an affidavit of that fact by the
  person claiming such Certificate to be lost, stolen or destroyed and the
  posting by such person of a bond in such amount as the Company may direct
  as indemnity against any claim that may be made against it or the Exchange
  Agent with respect to such Certificate, the Exchange Agent will issue in
  exchange for such lost, stolen or destroyed Certificate a certificate
  representing the proper number of shares of Company Common Stock or cash or
  both. Until surrendered as contemplated by this Section 1.9, 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 shares of Company Common Stock and cash in lieu of any
  fractional shares of Company Common Stock as contemplated by Section 1.9(e)
  or cash or both.
 
    (c) Distributions with Respect to Unexchanged Shares. No dividends or
  other distributions declared or made after the Effective Time with respect
  to Company 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 Company Common Stock represented thereby, and no cash payment in
  lieu of fractional shares shall be paid to any such holder pursuant to
  Section 1.9(e), until the holder of such Certificate shall surrender such
  Certificate. Subject to the effect of applicable laws, following surrender
  of any such Certificate, there shall be paid to the holder of the
  certificates representing whole shares of Company Common Stock issued in
  exchange therefor, without interest, (i) promptly, the amount of any cash
  payable with respect to a fractional share of Company Common Stock to which
  such holder is entitled pursuant to Section 1.9(e) and the amount of
  dividends or other distributions with a record date after the Effective
  Time theretofore paid with respect to such whole shares of Company Common
  Stock, and (ii) 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 occurring after surrender, payable with
  respect to such whole shares of Company Common Stock.
 
    (d) No Further Rights in the Shares. All shares of Company Common Stock
  issued and cash paid upon conversion of the Shares in accordance with the
  terms hereof (including any cash paid pursuant to Section 1.9(e)) shall be
  deemed to have been issued in full satisfaction of all rights pertaining to
  such Shares.
 
    (e) No Fractional Shares. No certificates or scrip representing
  fractional shares of Company Common Stock shall be issued upon the
  surrender for exchange of Certificates, and such fractional share interest
  will not entitle the owner thereof to vote or to any rights of a
  shareholder of the Company. Each holder of a fractional share interest
  shall be paid an amount in cash equal to the product obtained by
  multiplying such fractional share interest to which such holder (after
  taking into account all fractional share interests then held by such
  holder) would otherwise be entitled by the average of the final bid and
  asked price for a share of Company Common Stock as quoted by the NASDAQ/NMS
  on the five business days immediately preceding the Effective Time. As soon
  as reasonably practicable after the determination of the amount of cash, if
  any, to be paid to holders of fractional share interests, the Company shall
  make available such amounts (without interest) to such holders of such
  fractional share interests.
 
    (f) Termination of Exchange Fund. Any portion of the Exchange Fund which
  remains undistributed to the former shareholders of Seller for six months
  after the Effective Time shall be delivered to the Company, upon demand,
  and any former shareholders of Seller who have not theretofore complied
  with this Article I shall thereafter look only to the Company to claim
  their cash merger consideration, shares of Company Common Stock, any cash
  in lieu of fractional shares of Company Common Stock and any dividends or
  distributions with respect to Company Common Stock, in each case without
  interest thereon, and subject to Section 1.9(g).
 
                                      A-5
<PAGE>
 
    (g) No Liability. Neither the Company nor the Seller shall be liable to
  any former holder of Shares for any such Shares (or dividends or
  distributions with respect thereto) or cash or other payment delivered to a
  public official pursuant to any abandoned property, escheat or similar
  laws.
 
    (h) Withholding Rights. The Company shall be entitled to deduct and
  withhold from the consideration otherwise payable pursuant to this
  Agreement to any former holder of Shares such amounts as the Company is
  required to deduct and withhold with respect to the making of such payment
  under the Code, or any provision of state, local or foreign tax law. To the
  extent that amounts are so withheld by the Company, such withheld amounts
  shall be treated for all purposes of this Agreement as having been paid to
  the former holder of the Shares in respect of which such deduction and
  withholding was made by the Company.
 
  Section 1.10 Stock Transfer Books. At the Effective Time, the stock transfer
books of Seller shall be closed and there shall be no further registration of
transfers of shares of Seller Common Stock thereafter on the records of
Seller. From and after the Effective Time, the holders of certificates
evidencing ownership of shares of Seller Common Stock outstanding immediately
prior to the Effective Time shall cease to have any rights with respect to
such Shares except as otherwise provided herein or by law. On or after the
Effective Time, any Certificates presented to the Exchange Agent or the
Company for any reason shall be converted into cash, shares of Company Common
Stock or both in accordance with this Article I.
 
  Section 1.11 Company Common Stock. The shares of Company Common Stock issued
and outstanding immediately prior to the Effective Time shall be unaffected by
the Merger and at the Effective Time, such shares shall remain issued and
outstanding.
 
             ARTICLE II--REPRESENTATIONS AND WARRANTIES OF SELLER
 
  Except as set forth in the Disclosure Schedule delivered by Seller to the
Company prior to the execution of this Agreement (the "Seller Disclosure
Schedule"), Seller hereby represents and warrants to the Company that:
 
Section 2.1 Organization and Qualification; Subsidiaries.
 
    (a) Seller is a company duly organized, validly existing and in good
  standing under the laws of the State of Wisconsin, and is a registered
  unitary bank holding company under the Bank Holding Company Act of 1956, as
  amended (the "BHCA"). Each subsidiary of Seller ("Seller Subsidiary" or,
  collectively, "Seller Subsidiaries") is a bank or a corporation duly
  organized, validly existing and in good standing under the laws of the
  state of its incorporation. Each of Seller and the Seller Subsidiaries has
  the requisite corporate power and authority and is in possession of all
  franchises, grants, authorizations, licenses, permits, easements, consents,
  certificates, approvals and orders ("Seller Approvals") necessary to own,
  lease and operate its properties and to carry on its business as it is now
  being conducted, including appropriate authorizations from the Federal
  Reserve Board, the Federal Deposit Insurance Corporation (the "FDIC") and
  the Wisconsin Department of Financial Institutions ("DFI") Division of
  Savings Institutions ("Division of Savings Institutions") and neither
  Seller nor any Seller Subsidiary has received any notice of proceedings
  relating to the revocation or modification of any Seller Approvals, except
  in each case where the failure to be so organized, existing and in good
  standing or to have such power, authority, Seller Approvals and revocations
  or modifications would not, individually or in the aggregate, have a
  Material Adverse Effect (as defined below) on Seller and Seller
  Subsidiaries, taken as a whole.
 
    (b) Seller and each Seller Subsidiary is duly qualified or licensed as a
  foreign corporation to do business, and is in good standing, in each
  jurisdiction where the character of its properties owned, leased or
  operated by it or the nature of its activities makes such qualification or
  licensing necessary, except where such failures to be so duly qualified or
  licensed and in good standing that would not, either individually or in the
  aggregate, have a Material Adverse Effect on Seller and Seller
  Subsidiaries, taken as a whole.
 
                                      A-6
<PAGE>
 
    (c) A true and complete list of all of the Seller Subsidiaries, together
  with (i) the Seller's percentage ownership of each Seller Subsidiary and
  (ii) laws under which the Seller Subsidiary is incorporated, is set forth
  on Annex A. Except as set forth on Annex A, Seller and/or one or more of
  the Seller Subsidiaries owns beneficially and of record all of the
  outstanding shares of capital stock of each of the Seller Subsidiaries.
  Except for the subsidiaries set forth on Annex A, Seller does not directly
  or indirectly own any equity or similar interests in, or any interests
  convertible into or exchangeable or exercisable for any equity or similar
  interest in, any corporation, partnership, joint venture or other business
  association or entity other than in the ordinary course of business, and in
  no event in excess of 5% of the outstanding equity securities of such
  entity.
 
    (d) As used in this Agreement, the term "Material Adverse Effect" means,
  with respect to the Company or the Seller, as the case may be, any effect
  that (i) is material and adverse to the business, assets, liabilities,
  results of operations or financial condition of the Company and the Company
  Subsidiaries taken as whole or the Seller and Seller Subsidiaries taken as
  a whole, respectively, or (ii) materially impairs the ability of the
  Company or Seller to consummate the transactions contemplated hereby;
  provided, however, that Material Adverse Effect shall not be deemed to
  include the impact of (a) actions contemplated by this Agreement, (b)
  changes in laws and regulations or interpretations thereof that are
  generally applicable to the banking or savings industries, (c) changes in
  generally accepted accounting principles that are generally applicable to
  the banking or savings industries, (d) reasonable expenses incurred in
  connection with the transactions contemplated hereby, (e) changes
  attributable to or resulting from changes in general economic conditions
  affecting banks or their holding companies generally, including changes in
  the prevailing level of interest rates, and (f) any changes (financial or
  otherwise) attributable to the Data Processing Conversion.
 
    (e) The minute books of the Seller and each of the Seller Subsidiaries
  contain true, complete and accurate records in all material respects of all
  meetings and other corporate actions held or taken since December 31, 1993
  of their respective stockholders and Boards of Directors (including
  committees of their respective Boards of Directors).
 
  Section 2.2 Articles of Incorporation and By-Laws. Seller has heretofore
furnished to the Company a complete and correct copy of the Articles of
Incorporation and the By-Laws, as amended or restated, of Seller ("Seller
Articles" or "Seller By-Laws") and each Seller Subsidiary. Such Articles of
Incorporation and By-Laws of Seller and each Seller Subsidiary are in full
force and effect. Neither Seller nor any Seller Subsidiary is in violation of
any of the provisions of its Articles of Incorporation or By-Laws.
 
  Section 2.3 Capitalization. The authorized capital stock of Seller consists
of 50,000,000 shares of Seller Common Stock and 10,000,000 shares of preferred
stock, par value $1.00 per share ("Seller Preferred Stock"). As of the date of
this Agreement, (i) 9,202,932 shares of Seller Common Stock are issued and
outstanding (of which 112,700 are restricted shares under employee benefit
plans which have not and will not be awarded), all of which are duly
authorized, validly issued, fully paid and non-assessable, except as provided
by Section 180.0622(2)(b) of the WBCL, and not issued in violation of any
preemptive right of any Seller shareholder, (ii) 1,607,068 shares of Seller
Common Stock are held in the treasury of Seller, and (iii) 1,182,433 shares of
Seller Common Stock are reserved for future issuance pursuant to outstanding
employee stock options issued pursuant to Seller's stock option plans. As of
the date of this Agreement, no shares of Seller Preferred Stock are issued and
outstanding. Except as set forth in clause (iii), above, there are no options,
warrants or other rights, agreements, arrangements or commitments of any
character, including without limitation voting agreements or arrangements,
relating to the issued or unissued capital stock of Seller or any Seller
Subsidiary or obligating Seller or any Seller Subsidiary to issue or sell any
shares of capital stock of, or other equity interests in, Seller or any Seller
Subsidiary. All shares of Seller Common Stock subject to issuance as
aforesaid, upon issuance on the terms and conditions specified in the
instruments pursuant to which they are issuable, shall be duly authorized,
validly issued, fully paid and non-assessable, except as otherwise provided by
Section 180.0622(2)(b) of the WBCL (such section, including judicial
interpretations thereof and of Section 180.40(6), its predecessor statute, are
referred to herein as "Section 180.0622(2)(b) of the WBCL"). There are no
obligations, contingent or
 
                                      A-7
<PAGE>
 
otherwise, of Seller or any Seller Subsidiary to repurchase, redeem or
otherwise acquire any shares of Seller Common Stock or the capital stock of
any Seller Subsidiary or to provide funds to or make any investment (in the
form of a loan, capital contribution or otherwise) in any Seller Subsidiary or
any other entity, except for loan commitments and other funding obligations
entered into in the ordinary course of business. Each of the outstanding
shares of capital stock of each Seller Subsidiary are duly authorized, validly
issued, fully paid and non-assessable, except as provided by Section
180.0622(2)(b) of the WBCL and, in the case of Wisconsin state banks, Section
214.775 of the Wisconsin Statutes, and not in violation of any preemptive
rights of any Seller Subsidiary shareholder, and such shares owned by Seller
or another Seller Subsidiary are owned free and clear of all security
interests, liens, claims, pledges, agreements, limitations of Seller's voting
rights, charges or other encumbrances of any nature whatsoever.
 
  Section 2.4 Authority. Seller has the requisite corporate power and
authority to execute and deliver this Agreement to perform its obligations
hereunder and to consummate the transactions contemplated hereby and thereby
(other than, with respect to the Merger, the approval and adoption of this
Agreement by Seller's shareholders in accordance with the WBCL and the Seller
Articles and Seller By-Laws). The execution and delivery of this Agreement by
Seller and the consummation by Seller of the transactions contemplated hereby
have been duly and validly authorized by all necessary corporate action,
including without limitation Seller's Board of Directors, and no other
corporate proceedings on the part of Seller are necessary to authorize this
Agreement or to consummate the transactions so contemplated hereby (other
than, with respect to the Merger, the approval and adoption of this Agreement
by Seller's shareholders in accordance with the WBCL and the Seller Articles
and Seller By-Laws). The action of Seller's Board of Directors has been taken
in compliance with Article IV(c)(6) of the Seller Articles. This Agreement has
been duly executed and delivered by, and constitutes a valid and binding
obligation of Seller and assuming due authorization, execution and delivery by
Company, enforceable against Seller in accordance with its terms, except as
enforcement may be limited by laws affecting insured depository institutions,
general principles of equity whether applied in a court of law or a court of
equity and by bankruptcy, insolvency and similar laws affecting creditors'
rights and remedies generally.
 
  Section 2.5 No Conflict; Required Filings and Consents.
 
    (a) The execution and delivery of this Agreement by Seller does not, and
  the performance of this Agreement and the transactions contemplated hereby
  by Seller shall not, (i) conflict with or violate the Seller Articles or
  Seller By-Laws or the Articles of Incorporation or By-Laws of any Seller
  Subsidiary, (ii) conflict with or violate any domestic (federal, state or
  local) or foreign law, statute, ordinance, rule, regulation, order,
  judgment or decree (collectively, "Laws") applicable to Seller or any
  Seller Subsidiary or by which its or any of their respective properties is
  bound or affected, or (iii) result in any breach of or constitute a default
  (or an event that with notice or lapse of time or both would become a
  default) under, or give to others any rights of termination, amendment,
  acceleration or cancellation of, or result in the creation of a lien or
  encumbrance on any of the properties or assets of Seller or any Seller
  Subsidiary pursuant to, any note, bond, mortgage, indenture, contract,
  agreement, lease, license, permit, franchise or other instrument or
  obligation to which Seller or any Seller Subsidiary is a party or by which
  Seller or any Seller Subsidiary or its or any of their respective
  properties is bound or affected, except in the case of clauses (ii) and
  (iii) for any such conflicts, violations, breaches, defaults or other
  occurrences that would not, individually or in the aggregate, have a
  Material Adverse Effect on Seller and the Seller Subsidiaries, taken as a
  whole. The Board of Directors of Seller has taken all actions necessary
  including approving the transactions contemplated herein to ensure that
  none of the restrictions set forth in Sections 180.1130-32, 180.1134,
  180.1140-44 and 180.1150 of the WBCL do or will apply to the transactions
  contemplated herein.
 
    (b) The execution and delivery of this Agreement by Seller does not, and
  the performance of this Agreement by Seller shall not, require any consent,
  approval, authorization or permit of, or filing with or notification to,
  any governmental or regulatory authority, domestic or foreign, except (i)
  for applicable requirements, if any, of the Securities Act of 1933, as
  amended (the "Securities Act"), the Securities Exchange Act of 1934, as
  amended (the "Exchange Act"), state securities or blue sky laws ("Blue Sky
 
                                      A-8
<PAGE>
 
  Laws"), the BHCA, the banking laws of the State of Wisconsin (the "WBL")
  and the filing and recordation of appropriate merger or other documents as
  required by the WBCL where the failure to obtain such consents, approvals,
  authorizations or permits, or to make such filings or notifications, would
  not prevent Seller from performing its obligations under this Agreement,
  and would not have a Material Adverse Effect on Seller and Seller
  Subsidiaries, taken as a whole.
 
  Section 2.6 Compliance; Permits. Neither Seller nor any Seller Subsidiary is
in conflict with, or in default or violation of, (i) any Law applicable to
Seller or any Seller Subsidiary or by which its or any of their respective
properties is bound or affected, or (ii) any note, bond, mortgage, indenture,
contract, agreement, lease, license, permit, franchise or other instrument or
obligation to which Seller or any Seller Subsidiary is a party or by which
Seller or any Seller Subsidiary or its or any of their respective properties
is bound or affected, except for any such conflicts, defaults or violations
which would not, individually or in the aggregate, have a Material Adverse
Effect on Seller or Seller Subsidiaries, taken as a whole.
 
  Section 2.7 Securities and Banking Reports; Financial Statements.
 
    (a) Seller and each Seller Subsidiary have filed all forms, reports and
  documents required to be filed with (x) the Securities and Exchange
  Commission (the "SEC") since June 30, 1996, and as of the date of this
  Agreement has delivered to the Company (i) its Annual Reports on Form 10-K
  for the fiscal years ended June 30, 1994, 1995 and 1996, respectively, (ii)
  its Quarterly Reports on Form 10-Q for the periods ended September 30, 1996
  and December 31, 1996, (iii) all proxy statements relating to Seller's
  meetings of shareholders (whether annual or special) held since June 30,
  1994, (iv) all Reports on Form 8-K filed by Seller with the SEC since June
  30, 1994, (v) all other reports or registration statements (other than
  Reports on Form 10-Q not referred to in clause (ii) above, since June 30,
  1994) and (vi) all amendments and supplements to all such reports and
  registration statements filed by Seller with the SEC since June 30, 1994
  (collectively, the "Seller SEC Reports") and (y) the DFI and any other
  applicable federal or state securities or banking authorities (all such
  reports and statements are collectively referred to with the Seller SEC
  Reports as the "Seller Reports"). The Seller Reports, including all Seller
  Reports filed after the date of this Agreement, (i) were or will be
  prepared in all material respects in accordance with the requirements of
  applicable Law and (ii) did not at the time they were filed, or will not at
  the time they are filed, contain any untrue statement of a material fact or
  omit to state a material fact required to be stated therein or necessary in
  order to make the statements therein, in the light of the circumstances
  under which they were made, not misleading.
 
    (b) Each of the consolidated financial statements (including, in each
  case, any related notes thereto) contained in the Seller SEC Reports,
  including any Seller SEC Reports filed since the date of this Agreement and
  prior to or on the Effective Time, have been prepared in accordance with
  generally accepted accounting principles applied on a consistent basis
  throughout the periods involved (except as may be indicated in the notes
  thereto) and each fairly presents the consolidated financial position of
  Seller and Seller Subsidiaries as of the respective dates thereof and the
  consolidated results of its operations and changes in financial position
  for the periods indicated, except that any unaudited interim financial
  statements were or are subject to normal and recurring year-end adjustments
  which were not or are not expected to be material in amount.
 
    (c) Except (i) for those liabilities that are fully reflected or reserved
  against on the consolidated statement of condition of the Seller included
  in the Seller's Form 10-Q for the quarter ended December 31, 1996, (ii) for
  liabilities incurred in the ordinary course of business consistent with
  past practice since December 31, 1996, and (iii) as set forth in Section
  2.7 of the Seller Disclosure Schedule, neither Seller nor any Seller
  Subsidiary has incurred any liability of any nature whatsoever (whether
  absolute, accrued, contingent or otherwise due or to become due), that,
  either alone or when combined with all similar liabilities, has had, or
  would reasonably be expected to have, a Material Adverse Effect on the
  Seller and the Seller Subsidiaries, taken as a whole.
 
                                      A-9
<PAGE>
 
  Section 2.8 Absence of Certain Changes or Events. Except as disclosed in the
Seller SEC Reports filed prior to the date of this Agreement or set forth in
Section 2.8 of the Seller Disclosure Schedule, since December 31, 1996 to the
date of this Agreement, Seller and the Seller Subsidiaries have conducted
their businesses only in the ordinary course and in a manner consistent with
past practice and, since December 31, 1996, there has not been (i) any change
in the financial condition, results of operations or business of Seller and
any of the Seller Subsidiaries having a Material Adverse Effect on Seller or
the Seller Subsidiaries, taken as a whole, (ii) any damage, destruction or
loss (whether or not covered by insurance) with respect to any assets of
Seller or any of the Seller Subsidiaries having a Material Adverse Effect on
Seller and the Seller Subsidiaries, taken as a whole, (iii) any change by
Seller in its accounting methods, principles or practices, (iv) any
revaluation by Seller of any of its assets in any material respect, (v) except
for regular quarterly cash dividends on Seller Common Stock with usual record
and payment dates, to the date of this Agreement, any declaration, setting
aside or payment of any dividends or distributions in respect of shares of
Seller Common Stock or any redemption, purchase or other acquisition of any of
its securities or any of the securities of any Seller Subsidiary, (vi)
increased the wages, salaries, compensation, pension, or other fringe benefits
or perquisites payable to any executive officer, employee, or director from
the amount thereof in effect as of December 31, 1996 (which amounts have been
previously disclosed to Company), granted any severance or termination pay,
entered into any contract to make or grant any severance or termination pay,
or paid any bonus other than year-end bonuses for fiscal 1996 as listed in
Section 2.8 of the Seller Disclosure Schedule, (vii) suffered any strike, work
stoppage, slow-down or other labor disturbance, (viii) been a party to a
collective bargaining agreement, contract or other agreement or understanding
with a labor union or organization, or (ix) had any union organizing
activities.
 
  Section 2.9 Absence of Litigation. (a) Except as set forth in Section 2.9 of
the Seller Disclosure Schedule, neither the Seller nor any of the Seller
Subsidiaries is a party to any, and there are no pending or, to the best of
the Seller's knowledge, threatened, legal, administrative, arbitral or other
proceedings, claims, actions or governmental or regulatory investigations of
any nature against the Seller or any of the Seller Subsidiaries or challenging
the validity or propriety of the transactions contemplated by this Agreement
as to which there is reasonable probability of an adverse determination and
which, if adversely determined, would, individually or in the aggregate, have
a Material Adverse Effect on the Seller and the Seller Subsidiaries, taken as
a whole.
 
  (b) There is no injunction, order, judgment, decree or regulatory
restriction imposed upon the Company, any of the Seller Subsidiaries or the
assets of the Seller or any of the Seller Subsidiaries which has had a
Material Adverse Effect on the Seller and the Seller Subsidiaries, taken as a
whole.
 
  (c) The matter Brown, et. al. v. Security Capital Corporation has been
dismissed with prejudice and, as of March 19, 1996, all amounts due pursuant
to the settlement agreement relating thereto have been paid and expensed or
fully accrued for in the Seller's Financial Statements.
 
  Section 2.10 Employee Benefit Plans.
 
    (a) Section 2.10(a) of the Seller Disclosure Schedule lists (i) all
  employee benefit plans (as defined in Section 3(3) of the Employee
  Retirement Income Security Act of 1974, as amended ("ERISA")), and all
  bonus, stock option, stock purchase, restricted stock, incentive, deferred
  compensation, retiree medical or life insurance, supplemental retirement,
  severance or other benefit plans, programs or arrangements, and all
  material employment, termination, severance or other employment contracts
  or employment agreements, with respect to which Seller or any Seller
  Subsidiary has any obligation (collectively, the "Plans"). Seller has
  furnished or made available to the Company a complete and accurate copy of
  each Plan (or a description of the Plans, if the Plans are not in writing)
  and a complete and accurate copy of each material document prepared in
  connection with each such Plan, including, without limitation, and where
  applicable, a copy of (i) each trust or other funding arrangement, (ii)
  each summary plan description and summary of material modifications, (iii)
  the three (3) most recently filed IRS Forms 5500 and related schedules,
  (iv) the most recently issued IRS determination letter for each such Plan
  and (v) the three (3) most recently prepared actuarial and financial
  statements in connection with each such Plan.
 
                                     A-10
<PAGE>
 
    (b) Absence of Certain Types of Plans. Except as disclosed in the Seller
  Disclosure Schedule, no member of Seller's "controlled group," within the
  meaning of Section 4001(a)(14) of ERISA, maintains or contributes to, or
  within the five years preceding the Effective Time has maintained or
  contributed to, an employee pension benefit plan subject to Title IV of
  ERISA ("Title IV Plan"). No Title IV Plan is a "multiemployer pension plan"
  as defined in Section 3(37) of ERISA. Except as disclosed in the Seller
  Disclosure Schedule, none of the Plans obligates Seller or any of the
  Seller Subsidiaries to pay material separation, severance, termination or
  similar-type benefits solely as a result of any transaction contemplated by
  this Agreement or as a result of a "change in control," within the meaning
  of such term under Section 280G of the Code. Except as disclosed in the
  Seller Disclosure Schedule, or as required by COBRA, none of the Plans
  provides for or promises retiree medical, disability or life insurance
  benefits to any current or former employee, officer or director or life
  insurance benefits to any current or former employee, officer or director
  of Seller or any of the Seller Subsidiaries. Each of the Plans is subject
  only to the laws of the United States or a political subdivision thereof.
 
    (c) Compliance with Applicable Law. Except as disclosed in the Seller
  Disclosure Schedule, each Plan has been operated in all respects in
  accordance with the requirements of all applicable Law and all persons who
  participate in the operation of such Plans and all Plan "fiduciaries"
  (within the meaning of Section 3(21) of ERISA) have acted in accordance
  with the provisions of all applicable Law, except where such violations of
  applicable Law would not, individually or in the aggregate, have a Material
  Adverse Effect on Seller and the Seller Subsidiaries, taken as a whole.
  Seller and the Seller Subsidiaries have performed all obligations required
  to be performed by any of them under, are not in any respect in default
  under or in violation of, and Seller and the Seller Subsidiaries have no
  knowledge of any default or violation by any party to, any Plan, except
  where such failures, defaults or violations would not, individually or in
  the aggregate, have a Material Adverse Effect on Seller and the Seller
  Subsidiaries, taken as a whole. No legal action, suit or claim is pending
  or, to the knowledge of Seller or the Seller Subsidiaries, threatened with
  respect to any Plan (other than claims for benefits in the ordinary course)
  and, except as disclosed in the Seller Disclosure Schedule, to the
  knowledge of Seller or the Seller Subsidiaries, no fact or event exists
  that could give rise to any such action, suit or claim. Except as disclosed
  in the Seller Disclosure Schedule, neither Seller nor any Seller Subsidiary
  has incurred any material liability to the Pension Benefit Guaranty
  Corporation (other than for premiums which have been paid when due) or any
  material liability under Section 302 of ERISA or Section 412 of the Code
  that has not been satisfied in full and no condition exists that presents a
  material risk of incurring any such liability.
 
    (d) Qualification of Certain Plans. Each Plan that is intended to be
  qualified under Section 401(a) of the Code or Section 401(k) of the Code
  (including each trust established in connection with such a Plan that is
  intended to be exempt from Federal income taxation under Section 501(a) of
  the Code) has received a favorable determination letter from the IRS (as
  defined herein) that it is so qualified, and, except as disclosed in the
  Seller Disclosure Schedule Seller is not aware of any fact or event that
  has occurred since the date of such determination letter from the IRS to
  adversely affect the qualified status of any such Plan. Except as disclosed
  on the Seller Disclosure Schedule, no trust maintained or contributed by
  the Seller or any of the Seller Subsidiaries is intended to be qualified as
  a voluntary employees' beneficiary association or is intended to be exempt
  from federal income taxation under Section 501(c)(9) of the Code.
 
    (e) Absence of Certain Liabilities and Events. Except for matters
  disclosed in the Seller Disclosure Schedule, there has been no prohibited
  transaction (within the meaning of Section 406 of ERISA or Section 4975 of
  the Code) with respect to any Plan. Seller and each of the Seller
  Subsidiaries has not incurred any liability for any excise tax arising
  under Section 4972 or 4980B of the Code that would individually or in the
  aggregate have a Material Adverse Effect on the Seller and the Seller
  Subsidiaries, taken as a whole, and, to the knowledge of Seller or the
  Seller Subsidiaries, no fact or event exists that could give rise to any
  such liability.
 
    (f) Plan Contributions. All contributions, premiums or payments required
  to be made prior to the Effective Time with respect to any Plan have been
  made on or before the Effective Time.
 
                                     A-11
<PAGE>
 
    (g) Funded Status of Plans and Rights to Terminate. With respect to each
  Title IV Plan, the present value of all accrued benefits under each such
  Plan, based upon the actuarial assumptions used for funding purposes in the
  most recent actuarial report prepared by each such Plan's actuary with
  respect to each such Plan did not exceed, as of the most recent valuation
  date, the then current value of assets of such Plan allocable to each
  accrued benefit. No provision of any such Plan, nor any amendment thereto,
  would result in any limitation on Seller or Seller's Subsidiaries rights,
  or Buyer's request, to terminate each such Plan and to receive any residual
  amounts under Section 4044 of ERISA.
 
    (h) Stock Options. Section 2.10(g) of the Seller Disclosure Schedule sets
  forth a true and complete list of each current or former employee, officer
  or director of Seller or any Seller Subsidiary who holds any option to
  purchase Seller Common Stock as of the date of this Agreement, together
  with the number of shares of Seller Common Stock subject to such option,
  the date of grant of such option, the option price of such option, whether
  such option is intended to qualify as an incentive stock option within the
  meaning of Section 422(b) of the Code (an "ISO"), and the expiration date
  of such option. Section 2.10(g) of the Seller Disclosure Schedule also sets
  forth the total number of such ISOs and such non-qualified options.
 
    (i) Employment Contracts. Except for employment, severance, consulting or
  other similar contracts with any employees, consultants, officers or
  directors of Seller or any of the Seller Subsidiaries disclosed in Section
  2.10(i) of the Seller Disclosure Schedule, neither Seller nor any Seller
  Subsidiary is a party to any such contracts. Neither Seller nor any Seller
  Subsidiary is a party to any collective bargaining agreements.
 
    (j) Effect of Agreement. Except as disclosed on the Seller Disclosure
  Schedule, the consummation of the transactions contemplated by this
  Agreement will not, either alone or in conjunction with another event,
  entitle any current or former employee of Seller or any Seller Subsidiary
  to severance pay, unemployment compensation or any other payment, except as
  expressly provided herein, or accelerate the time of payment or vesting or
  increase the compensation due any such employee or former employee, in each
  case, except as expressly provided herein.
 
  Section 2.11 Registration Statement; Proxy Statement/Prospectus. The
information supplied by Seller for inclusion in the Registration Statement (as
defined in Section 3.10) shall not at the time the Registration Statement is
declared effective 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 the light of the circumstances under which
they were made, not misleading. The information supplied by Seller for
inclusion in the proxy statement/prospectus to be sent to the shareholders of
Seller in connection with the meeting of Seller's shareholders to consider the
Merger (the "Seller Shareholders' Meeting") (such proxy statement/prospectus
as amended or supplemented is referred to herein as the "Proxy
Statement/Prospectus") shall not at the date the Proxy Statement/Prospectus
(or any amendment thereof or supplement thereto) is first mailed to
shareholders, at the time of the Seller Shareholders' Meeting and at the
Effective Time, be false or misleading with respect to any material fact
required to be stated herein, or omit to state any material fact required to
be stated therein or necessary in order to make the statements made therein,
in the light of the circumstances under which they are made, not misleading.
If at any time prior to the Effective Time any event relating to Seller or any
of its affiliates, officers or directors should be discovered by Seller which
should be set forth in an amendment to the Registration Statement or a
supplement to the Proxy Statement/Prospectus, Seller shall promptly inform the
Company. The Proxy Statement/Prospectus shall comply in all material respects
as to form with the requirements of the Securities Act, the Exchange Act and
the rules and regulations thereunder. Notwithstanding the foregoing, Seller
makes no representation or warranty with respect to any information about, or
supplied or omitted by, the Company which is contained in any of the foregoing
documents.
 
  Section 2.12 Title to Property. Seller and each of the Seller Subsidiaries
has good and marketable title to all of their respective properties and
assets, real and personal, free and clear of all mortgage liens, and free and
clear of all other liens, charges and encumbrances except liens for taxes not
yet due and payable, pledges to secure deposits and such minor imperfections
of title, if any, as do not materially detract from the value of or interfere
with the present use of the property affected thereby or which, individually
or in the aggregate, would not have a Material Adverse Effect on Seller and
the Seller Subsidiaries, taken as a whole; and all leases pursuant
 
                                     A-12
<PAGE>
 
to which Seller or any of the Seller Subsidiaries lease from others material
amounts of real or personal property are in good standing, valid and effective
in accordance with their respective terms, and there is not, under any of such
leases, any existing material default or event of default (or event which with
notice or lapse of time, or both, would constitute a material default and in
respect of which the Seller or such Seller Subsidiary has not taken adequate
steps to prevent such a default from occurring). Substantially all of Seller's
and each of the Seller's Subsidiaries' buildings and equipment in regular use
have been reasonably maintained and are in good and serviceable condition,
reasonable wear and tear excepted.
 
  Section 2.13 Environmental Matters. Except as set forth in Section 2.13 of
the Seller Disclosure Schedule, Seller represents and warrants that to the
best of Seller's knowledge: (i) each of the Seller, the Seller's Subsidiaries,
properties owned or operated by the Seller or the Seller's Subsidiaries, the
Participation Facilities and the Loan Properties (each as hereinafter defined)
are and have been in compliance with all applicable federal, state and local
laws including common law, rules, guidance, regulations and ordinances and
with all applicable decrees, orders, judgments, and contractual obligations
relating to the environment, health, safety, natural resources, wildlife or
hazardous materials which are hereinafter defined as chemicals, pollutants,
contaminants, wastes, toxic substances, compounds, products, solid, liquid,
gas, petroleum or other regulated substances or materials which are hazardous,
toxic or otherwise harmful to health, safety, natural resources, or the
environment ("Environmental Laws"), except for violations which, either
individually or in the aggregate would not have a Material Adverse Effect on
Seller or Seller's Subsidiaries; (ii) during and prior to the period of (a)
the Seller or any of the Seller's Subsidiaries ownership or operation of any
of their respective current properties, (b) the Seller or any of the Seller's
Subsidiaries participation in the management of any Participation Facility or
(c) the Seller's or any of the Seller's Subsidiaries holding of a security
interest in a Loan Property, Hazardous Materials have not been generated,
treated, stored, transported, released or disposed of in, on, under, above,
from or affecting any such property, except where such release, generation,
treatment, storage, transportation, or disposal would not have either
individually or in the aggregate, a Material Adverse Effect on the Seller or
Seller's Subsidiaries; (iii) there is no asbestos or any material amount
ureaformaldehyde materials in or on any property owned or operated by Seller
or Seller's Subsidiaries or any Loan Property or Participation Facility and no
electrical transformers or capacitors, other than those owned by public
utility companies, on any such properties contain any PCB's; (iv) there are no
underground or aboveground storage tanks and there have never been any
underground or aboveground storage tanks located on, in or under any
properties currently or formerly owned or operated by the Seller or any of
Seller's Subsidiaries or any Loan Property or Participation Facility; (v)
Seller or Seller's Subsidiaries have not received any notice from any
governmental agency or third party notifying the Seller or Seller's
Subsidiaries of any Environmental Claim; (vi) and there are no circumstances
with respect to any properties currently owned or operated by the Seller or
any of Seller's Subsidiaries or any Loan Property or Participation Facility
that could reasonably be anticipated (a) to form the basis on an Environmental
Claim against Seller or Seller's Subsidiaries or any properties currently or
formerly owned or operated by the Seller or any of Seller's Subsidiaries or
any Loan Property or Participation Facility or (b) to cause any properties
currently owned or operated by the Seller or any of Seller's Subsidiaries or
any Loan Property or Participation Facility to be subject to any restrictions
on ownership, occupancy, use or transferability under any applicable
Environmental Law or require notification to or consent of any Governmental
Authority or third party pursuant to any Environmental Law.
 
  The following definitions apply for purposes of this Section 2.13: (a) "Loan
Property" means any property in which the Seller or any of the Seller's
Subsidiaries holds a security interest, and, where required by the context,
said term means the owner or operator of such property; (b) "Participation
Facility" means any facility in which the Seller or any of the Seller's
Subsidiaries participates in the management and, where required by the
context, said term means the owner or operator of such property; (c)
"Environmental Claims" shall mean any and all administrative, regulatory,
judicial or private actions, suits, demands, demand letters, notices, claims,
liens, notices of non-compliance or violation, investigations, allegations,
injunctions or proceedings relating in any way to (i) any Environmental Law;
(ii) any Hazardous Material including without limitation any abatements,
removal, remedial, corrective or other response action in connection with any
Hazardous Material,
 
                                     A-13
<PAGE>
 
Environmental Law or order of a Governmental Authority or (iii) any actual or
alleged damage, injury, threat or harm to health, safety, natural resources,
wildlife, or the environment, which individually or in the aggregate would
have a Material Adverse Effect on Seller or Seller's Subsidiaries; (d)
"Governmental Authority" shall mean any applicable federal, state, regional,
county or local person or body having governmental authority.
 
  Section 2.14 Absence of Agreements. Neither Seller nor any Seller Subsidiary
is a party to any agreement or memorandum of understanding with, or a party to
any commitment letter or similar undertaking to, or is subject to any order or
directive by, or is a recipient of any extraordinary supervisory letter which
restricts materially the conduct of its business (including any contract
containing covenants which limit the ability of Seller or of any Seller
Subsidiary to compete in any line of business or with any person or which
involve any restriction of the geographical area in which, or method by which,
Seller or any Seller Subsidiary may carry on its business (other than as may
be required by Law or applicable regulatory authorities)), or in any manner
relates to its capital adequacy, its credit policies or its management, except
for those the existence of which has been disclosed to the Company prior to
the date of this Agreement, nor has Seller been advised that any federal,
state, or governmental agency is contemplating issuing or requesting (or is
considering the appropriateness of issuing or requesting) any such order,
decree, agreement, memorandum of understanding, extraordinary supervisory
letter, commitment letter or similar submission, except as disclosed by Seller
in Section 2.14 of the Seller Disclosure Schedule.
 
  Section 2.15 Taxes. Seller and the Seller Subsidiaries have timely filed all
Material Tax Returns (as defined below) required to be filed by them, and
Seller and the Seller Subsidiaries have timely paid and discharged all
Material Taxes (as defined below) due in connection with or with respect to
the filing of such Tax Returns, except such as are being contested in good
faith by appropriate proceedings and with respect to which Seller is
maintaining reserves adequate for their payment. To the best of the knowledge
of Seller, the liability for Taxes set forth on each such Tax Return
adequately reflects the Taxes required to be reflected on such Tax Return. For
purposes of this Agreement, "Tax" or "Taxes" shall mean taxes, charges, fees,
levies, and other governmental assessments and impositions of any kind,
payable to any federal, state, local or foreign governmental entity or taxing
authority or agency, including, without limitation, (i) income, franchise,
profits, gross receipts, estimated, ad valorem, value added, sales, use,
service, real or personal property, capital stock, license, payroll,
withholding, disability, employment, social security, workers compensation,
unemployment compensation, utility, severance, production, excise, stamp,
occupation, premiums, windfall profits, transfer and gains taxes, (ii) customs
duties, imposts, charges, levies or other similar assessments of any kind, and
(iii) interest, penalties and additions to tax imposed with respect thereto;
and "Tax Returns" shall mean returns, reports, and information statements with
respect to Taxes required to be filed with the United States Internal Revenue
Service (the "IRS") or any other governmental entity or taxing authority or
agency, domestic or foreign, including, without limitation, consolidated,
combined and unitary tax returns. Except as otherwise disclosed in the
Seller's Disclosure Schedule, to the best knowledge of the Seller, neither the
IRS nor any other governmental entity or taxing authority or agency is now
asserting, either through audits, administrative proceedings or court
proceedings, any deficiency or claim for additional Taxes. Except as otherwise
disclosed, neither Seller nor any of the Seller Subsidiaries has granted any
waiver of any statute of limitations with respect to, or any extension of a
period for the assessment of, any Tax. Except as otherwise disclosed in the
Seller's Disclosure Schedule and except for statutory liens for current taxes
not yet due, there are no material tax liens on any assets of Seller or any of
the Seller Subsidiaries. Except as otherwise disclosed in the Seller's
Disclosure Schedule neither Seller nor any of the Seller Subsidiaries has
received a ruling or entered into an agreement with the IRS or any other
taxing authority that would have a Material Adverse Effect on Seller or the
Seller Subsidiaries, taken as a whole, after the Effective Time. Except as
otherwise disclosed in the Seller's Disclosure Schedule, no agreements
relating to allocating or sharing of Taxes exist among Seller and the Seller
Subsidiaries. Neither Seller nor any of the Seller Subsidiaries has made an
election under Section 341(f) of the Code.
 
  Section 2.16 Insurance. Section 2.16 of the Seller Disclosure Schedule lists
all material policies of insurance of Seller and the Seller Subsidiaries
currently in effect. Neither Seller nor any of the Seller Subsidiaries
 
                                     A-14
<PAGE>
 
has any liability for unpaid premiums or premium adjustments not properly
reflected on Seller's financial statements included in Seller's Report on Form
10-Q for the quarter ended December 31, 1996.
 
  Section 2.17 Brokers. No broker, finder or investment banker (other than
Robert W. Baird and Company, Inc.) is entitled to any brokerage, finder's or
other fee or commission in connection with the transactions contemplated by
this Agreement based upon arrangements made by or on behalf of Seller. Prior
to the date of this Agreement, Seller has furnished to the Company a complete
and correct copy of all agreements between Seller and Robert W. Baird and
Company, Inc. pursuant to which such firm would be entitled to any payment
relating to the transactions contemplated hereunder.
 
  Section 2.18 Tax Matters.
 
    (a) Neither Seller nor, to the best of Seller's knowledge, any of its
  affiliates has through the date of this Agreement taken or agreed to take
  any action that would prevent the Merger from qualifying as a
  reorganization under Section 368(a)(1)(A) of the Code.
 
    (b) To Seller's knowledge, there is no plan or intention on the part of
  any Seller Affiliate (as defined below) who will receive Company Common
  Stock to sell or otherwise dispose of an amount of Company Common Stock to
  be received in the Merger which would reduce the ownership of Seller's
  Shareholders in Company Common Stock to a number of shares having in the
  aggregate a value at the time of the Merger of less than 50 percent of the
  total value of the Seller Common Stock outstanding immediately prior to the
  Merger.
 
  Section 2.19 Material Adverse Effect. Since December 31, 1996, there has
been no Material Adverse Effect on Seller and the Seller Subsidiaries, taken
as a whole.
 
  Section 2.20 Material Contracts. Except as disclosed in the Seller
Disclosure Schedule (which may reference other sections of such Schedule) and,
except as included as exhibits in the Seller SEC Reports, neither the Seller
nor any Seller Subsidiary is a party to or obligated under any contract,
agreement or other instrument or understanding which is not terminable by
Seller or the Seller Subsidiary without additional payment or penalty within
60 days and obligates Seller or any Seller Subsidiary for payments or other
consideration with a value in excess of $100,000, or would require disclosure
by Seller pursuant to item 601(b)(10) of Regulation S-K under the Exchange
Act.
 
  Section 2.21 Opinion of Financial Advisor. Seller has received the opinion
of Robert W. Baird and Company, Inc. on the date of this Agreement to the
effect that, as of the date of this Agreement, the consideration to be
received in the Merger by Seller's shareholders is fair to Seller's
shareholders from a financial point of view, and Seller will promptly, after
the date of this Agreement, deliver a copy of such opinion to the Company.
 
  Section 2.22 Vote Required. The affirmative vote of a majority of the votes
that holders of the outstanding shares of Seller Common Stock are entitled to
cast is the only vote of the holders of any class or series of Seller capital
stock necessary to approve the Merger.
 
  Section 2.23 Options; Employment Agreements. Seller will use all reasonable
efforts to cause each holder of an option to purchase Seller Common Stock to,
concurrently with the execution of this Agreement, execute an agreement
amending the terms of such option in the form of Exhibit 2.23 (an "Option
Exercise Agreement"), and to cause each director or officer of Seller who is a
party to, or a participant in, the Employment Contract, the Deferred
Compensation Plan for Officers, the Nonemployee Director Deferred Compensation
Plan or the Nonemployee Director Retirement Plan to execute an agreement
amending the relevant contract or agreement as regards that director or
officer in the form of Exhibit 2.23. To the extent that Seller is unable to
obtain Option Exercise Agreements and amendments to the Employment Agreement,
currently with the execution of this Agreement, Seller shall continue to use
all reasonable efforts to obtain such agreements as soon as practicable after
the date of this Agreement. As of date hereof, the individuals listed on
Section 2.23 of the Seller Disclosure Schedule have executed Option Exercise
Agreements. Seller may waive on behalf of both
 
                                     A-15
<PAGE>
 
Seller and the Company any requirement contained in any such agreement
restricting the exercise of stock options with respect to no more than 500,000
shares of Seller Common Stock, less the amount, if any, of options for which
Option Exercise Agreements have not been executed.
 
          ARTICLE III--REPRESENTATIONS AND WARRANTIES OF THE COMPANY
 
  Except as set forth in the Disclosure Schedule delivered by the Company to
Seller prior to the execution of this Agreement (the "Company Disclosure
Schedule"), which shall identify exceptions by specific Section references,
the Company hereby represents and warrants to Seller that:
 
  Section 3.1 Organization and Qualification; Subsidiaries.
 
    (a) The Company is a company duly organized, validly existing and in good
  standing under the laws of the State of Wisconsin and a registered bank
  holding company under the BHCA. Each subsidiary of the Company (a "Company
  Subsidiary" or, collectively, "Company Subsidiaries") is a bank or a
  corporation duly organized, validly existing and in good standing under the
  laws of the state of its incorporation or the United States of America.
  Each of the Company and the Company Subsidiaries have the requisite
  corporate power and authority and are in possession of all franchises,
  grants, authorizations, licenses, permits, easements, consents,
  certificates, approvals and orders ("Company Approvals") necessary to own,
  lease and operate their respective properties and to carry on their
  respective business as now being conducted, including appropriate
  authorizations from the Federal Reserve Board, the FDIC, the DFI or the OCC
  and neither Seller nor any Seller Subsidiary has received any notice of
  proceedings relating to the revocation or modification of any Seller
  Approvals, except in each case where the failure to be so organized,
  existing and in good standing or to have such power, authority, Company
  Approvals and revocations or modifications would not, individually or in
  the aggregate, have a Material Adverse Effect on the Company and the
  Company Subsidiaries, taken as a whole.
 
    (b) The Company and each Company Subsidiary is duly qualified or licensed
  as a foreign corporation to do business, and is in good standing, in each
  jurisdiction where the character of its properties owned, leased or
  operated by it or the nature of its activities makes such qualification or
  licensing necessary, except for such failures to be so duly qualified or
  licensed and in good standing that would not, either individually or in the
  aggregate, have a Material Adverse Effect on the Company and the Company
  Subsidiaries, taken as a whole.
 
    (c) A true and complete list of all of the Company Subsidiaries is set
  forth in Exhibit 21 to the Company's Annual Report on Form 10-K for the
  year ended December 31, 1996 ("Exhibit 21") previously delivered to Seller.
  Except as set forth in the Company Disclosure Schedule, the Company and/or
  one or more of the Company Subsidiaries owns beneficially and of record
  substantially all of the outstanding shares of capital stock of each of the
  Company Subsidiaries. Except for the Company Subsidiaries, set forth on
  said Exhibit 21, the Company does not directly or indirectly own any equity
  or similar interests in, or any interests convertible into or exchangeable
  or exercisable for any equity or similar interest in, any corporation,
  partnership, joint venture or other business, other than in the ordinary
  course of business, and in no event in excess of 5% of the outstanding
  equity securities of such entity.
 
  Section 3.2 Articles of Incorporation and By-Laws. The Company has
previously furnished to Seller a complete and correct copy of the Company
Articles and the Company By-Laws. The Company Articles and Company By-Laws are
in full force and effect. The Company is not in violation of any of the
provisions of the Company Articles or the Company By-Laws.
 
  Section 3.3 Capitalization.
 
    (a) The authorized capital stock of the Company consists of (i)
  160,000,000 shares of Company Common Stock of which, as of February 28,
  1997, 88,921,199 shares were issued and outstanding, 10,573,136 shares were
  held in treasury, 7,195,993 shares were reserved for issuance pursuant to
 
                                     A-16
<PAGE>
 
  outstanding employee stock options, 5,775,071 shares were reserved for
  issuance pursuant to the exchange of the Company Preferred Stock (as
  defined below) and 1,9922,115 shares were reserved for issuance pursuant to
  8 1/2% Convertible Subordinated Notes due 1997; (ii) 5,000,000 shares of
  Preferred Stock, $1.00 par value ("Company Preferred Stock"), of which
  2,000,000 shares of Company Preferred Stock has been designated as Series A
  Convertible Preferred Stock ("Series A Preferred Stock") and 517,129 of
  which, as of the date of this Agreement, are outstanding. All of the
  outstanding shares of the Company's capital stock have been duly authorized
  and validly issued and are fully paid and non-assessable, except pursuant
  to Section 180.0622(2)(b) of the WBCL. Except as set forth in clauses (i)-
  (ii), above, as of the date of this Agreement there are no options,
  warrants or other rights, agreements, arrangements or commitments of any
  character relating to the issued or unissued capital stock of the Company
  or any Company Subsidiary or obligating the Company or any Company
  Subsidiary to issue or sell any shares of capital stock of, or other equity
  interests in, the Company or any Company Subsidiary.
 
    (b) The shares of Company Common Stock to be issued pursuant to the
  Merger will, upon issuance in accordance with the provisions of this
  Agreement, be duly authorized, validly issued, fully paid and non-
  assessable, except as otherwise provided by Section 180.0622(2)(b) of the
  WBCL.
 
  Section 3.4 Authority. The Company has the requisite corporate power and
authority to execute and deliver this Agreement, and to perform its
obligations hereunder and to consummate the transactions contemplated hereby.
The execution and delivery of this Agreement by the Company and the
consummation by the Company of the transactions contemplated hereby has been
duly and validly authorized by all necessary corporate action on the part of
the Company, including without limitation the Company's Board of Directors,
and no other corporate proceedings on the part of the Company are necessary to
authorize this Agreement or to consummate the transactions so contemplated
hereby. This Agreement has been duly and validly executed and delivered by,
the Company and constitutes a valid and binding obligation of the Company and
assuming the authorization, execution and delivery by the Seller, enforceable
against the Company in accordance with its terms, except as enforcement may be
limited by laws affecting insured depository institutions, general principles
of equity, whether applied in a court of law or a court of equity, and by
bankruptcy, insolvency and similar laws affecting creditors' rights and
remedies generally.
 
  Section 3.5 No Conflict; Required Filings and Consents.
 
    (a) The execution and delivery of this Agreement by the Company does not,
  and the performance of this Agreement by the Company shall not, (i)
  conflict with or violate the Company Articles or Company By-Laws or the
  Articles of Incorporation or By-Laws any Company Subsidiary, (ii) conflict
  with or violate any Laws applicable to the Company or any Company
  Subsidiary or by which any of their respective properties is bound or
  affected, or (iii) result in any breach of or constitute a default (or an
  event which with notice or lapse of time or both would become a default)
  under, or give to others any rights of termination, amendment, acceleration
  or cancellation of, or result in the creation of a lien or encumbrance on
  any of the properties or assets of the Company or any Company Subsidiary
  pursuant to, any note, bond, mortgage, indenture, contract, agreement,
  lease, license, permit, franchise or other instrument or obligation to
  which the Company or any Company Subsidiary is a party or by which the
  Company or any Company Subsidiary or its or any of their respective
  properties is bound or affected, except in the case of clause (ii) and
  (iii) for any such conflicts, violations, breaches, defaults or other
  occurrences that would not, individually or in the aggregate, have a
  Material Adverse Effect on the Company and the Company Subsidiaries, taken
  as a whole.
 
    (b) The execution and delivery of this Agreement by the Company does not,
  and the performance of this Agreement by the Company shall not, require any
  consent, approval, authorization or permit of, or filing with or
  notification to, any governmental or regulatory authority, domestic or
  foreign, except (i) for applicable requirements, if any, of the Securities
  Act, the Exchange Act, Blue Sky Laws, the BHCA, the WBL and the filing and
  recordation of appropriate merger or other documents as required by
  Wisconsin law and (ii) where the failure to obtain such consents,
  approvals, authorizations or permits, or to make such filings or
  notifications, would not prevent or delay consummation of the Merger, or
  otherwise prevent the
 
                                     A-17
<PAGE>
 
  Company from performing its obligations under this Agreement, and would not
  have a Material Adverse Effect on the Company or the Company Subsidiaries,
  taken as a whole.
 
  Section 3.6 Compliance; Permits. Neither the Company nor any Company
Subsidiary is in conflict with, or in default or violation of, (i) any Law
applicable to the Company or any Company Subsidiary or by which its or any of
their respective properties is bound or affected, or (ii) any note, bond,
mortgage, indenture, contract, agreement, lease, license, permit, franchise or
other instrument or obligation to which the Company or any Company Subsidiary
is a party or by which the Company or any Company Subsidiary or any of its or
any of their respective properties is bound or affected, except for any such
conflicts, defaults or violations which would not, individually or in the
aggregate, have a Material Adverse Effect on the Company or the Company
Subsidiaries, taken as a whole.
 
  Section 3.7 Securities and Banking Reports; Financial Statements.
 
    (a) The Company and each Company Subsidiary have filed all forms, reports
  and documents required to be filed with (x) the SEC since December 31,
  1996, and as of the date of this Agreement have delivered or made available
  to Seller, in the form filed with the SEC, (i) its Annual Reports on Form
  10-K for the fiscal years ended December 31, 1994, 1995 and 1996,
  respectively, (ii) all proxy statements relating to the Company's meetings
  of shareholders (whether annual or special) held since December 31, 1994,
  (iii) all Reports on Form 8-K filed by the Company with the SEC since
  December 31, 1994, (iv) all other reports or registration statements (other
  than Reports on Form 10-Q not referred to in clause (ii) above) filed by
  the Company with the SEC since December 31, 1994, and (v) all amendments
  and supplements to all such reports and registration statements filed by
  the Company with the SEC since December 31, 1994 (collectively, the
  "Company SEC Reports") and (y) the Federal Reserve Board, the DFI and any
  other applicable Federal or state securities or banking authorities (all
  such reports and statements are collectively referred to with the Company
  SEC Reports as the "Company Reports"). The Company Reports, including all
  Company Reports filed after the date of this Agreement, (i) were or will be
  prepared in accordance with the requirements of applicable Law and (ii) did
  not at the time they were filed, or will not at the time they are filed,
  contain any untrue statement of a material fact or omit to state a material
  fact required to be stated therein or necessary in order to make the
  statements therein, in light of the circumstances under which they were
  made, not misleading.
 
    (b) Each of the consolidated financial statements (including, in each
  case, any related notes thereto) contained in the Company SEC Reports,
  including any Company SEC Reports filed since the date of this Agreement
  and prior to or on the Effective Time, have been prepared in accordance
  with generally accepted accounting principles applied on a consistent basis
  throughout the periods involved (except as may be indicated in the notes
  thereto) and each fairly presents the consolidated financial position of
  the Company and the Company Subsidiaries as of the respective dates thereof
  and the consolidated results of its operations and changes in financial
  position for the periods indicated, except that any unaudited interim
  financial statements were or are subject to normal and recurring year-end
  adjustments, which were not or are not expected to be material in amount.
 
    (c) Except (i) for those liabilities that are fully reflected or reserved
  against on the consolidated statement of condition of the Company included
  in the Company Form 10-K for the year ended December 31, 1996, (ii) for the
  liabilities incurred in the ordinary course of business consistent with
  past practice since December 31, 1996, and (iii) as set forth in Section
  3.7 of the Company Disclosure Schedule, neither Company nor any Company
  Subsidiary has incurred any liability of any nature whatsoever (whether
  absolute, accrued, contingent or otherwise and whether due or to become
  due) that, either alone or when combined with all similar liabilities, has
  had, or would reasonably be expected to have, a Material Adverse Effect on
  the Company and the Company Subsidiaries, taken as a whole.
 
  Section 3.8 Absence of Certain Changes or Events. Except as disclosed in the
Company SEC Reports filed prior to the date of this Agreement, since December
31, 1996 to the date of this Agreement, the Company and the Company
Subsidiaries have conducted their businesses only in the ordinary course and
in a manner
 
                                     A-18
<PAGE>
 
consistent with past practice and, since December 31, 1996, there has not been
(i) any change in the financial condition, results of operations or business
of the Company or any of the Company Subsidiaries having a Material Adverse
Effect on the Company and the Company Subsidiaries, taken as a whole, (ii) any
damage, destruction or loss (whether or not covered by insurance) with respect
to any assets of the Company or any of the Company Subsidiaries having a
Material Adverse Effect on the Company and the Company Subsidiaries, taken as
a whole, (iii) any change by the Company in its accounting methods, principles
or practices, (iv) any revaluation by the Company of any of its assets in any
respect, (v) to the date of this Agreement, any entry by the Company or any of
the Company Subsidiaries into any commitment or transactions material to the
Company and the Company Subsidiaries taken as a whole or (vi) except for
repurchases pursuant to the Company's Common Stock repurchase program or for
regular quarterly cash dividends of Company Common Stock with usual record and
payment dates, to the date of this Agreement, any declaration, setting aside
or payment of any dividends or distributions in respect of shares of Company
Common Stock or any redemption, purchase or other acquisition of any of its
securities or any of the securities of any Company Subsidiary.
 
  Section 3.9 Absence of Litigation.
 
    (a) Except as set forth in Section 3.9 of the Company Disclosure
  Schedule, neither the Company nor any of the Company Subsidiaries is a
  party to any, and there are no pending or, to the best of the Company's
  knowledge, threatened, legal, administrative, arbitral or other
  proceedings, claims, actions or governmental or regulatory investigations
  of any nature against the Company or any of the Company Subsidiaries or
  challenging the validity or propriety of the transactions contemplated by
  this Agreement as to which there is a reasonable probability of an adverse
  determination and which, if adversely determined, would, individually or in
  the aggregate, have a Material Adverse Effect on the Company and the
  Company's Subsidiaries, taken as a whole.
 
    (b) There is no injunction, order, judgment, decree or regulatory
  restriction imposed upon the Company, any of the Company Subsidiaries or
  the assets of the Company or any of the Company Subsidiaries which has had
  a Material Adverse Effect on the Company and the Company's Subsidiaries,
  taken as a whole.
 
  Section 3.10 Employee Benefit Plans.
 
    (a) Compliance with Applicable Laws. Each of the Company's "employee
  benefit plans" within the meaning of Section 3(3) of ERISA, for the benefit
  of employees of the Company and the Company Subsidiaries (the "Company
  Plans") has been operated in all respects in accordance with the
  requirements of all applicable Law and all persons who participate in the
  operation of such Company Plans and all Company Plan "fiduciaries" (within
  the meaning of Section 3(21) of ERISA) have acted in accordance with the
  provisions of all applicable Law, except where such violations of
  applicable Law would not, individually or in the aggregate, have a Material
  Adverse Effect on the Company and the Company Subsidiaries, taken as a
  whole. The Company and the Company Subsidiaries have performed all
  obligations required to be performed by any of them under, are not in any
  respect in default under or in violation of, and the Company and the
  Company Subsidiaries have no knowledge of any default or violation by any
  party to, any Company Plan, except where such failures, defaults or
  violations would not, individually or in the aggregate, have a Material
  Adverse Effect on the Company and the Company Subsidiaries, taken as a
  whole. No legal action, suit or claim is pending or, to the knowledge of
  the Company or the Company Subsidiaries, threatened with respect to any
  Company Plan (other than claims for benefits in the ordinary course) and,
  to the knowledge of the Company or the Company Subsidiaries, no fact or
  event exists that could give rise to any such action, suit or claim.
 
    (b) Qualification of Certain Plans. Each Company Plan that is intended to
  be qualified under Section 401(a) of the Code or Section 401(k) of the Code
  (including each trust, established in connection with such a Plan that is
  intended to be exempt from Federal income taxation under Section 501(a) of
  the Code) has received a favorable determination letter from the IRS (as
  defined herein) that it is so qualified, and the Company is not aware of
  any fact or event that has occurred since the date of such determination
  letter from the IRS to adversely affect the qualified status of any Company
  Plan or the exempt status of any such
 
                                     A-19
<PAGE>
 
  trust. No trust maintained or contributed to by the Company or any of the
  Company Subsidiaries is intended to be qualified as a voluntary employees'
  beneficiary association or is intended to be exempt from federal income
  taxation under Section 501(c)(9) of the Code.
 
    (c) Absence of Certain Liabilities and Events. There have been no
  prohibited transactions (within the meaning of Section 406 of ERISA or
  Section 4975 of the Code) with respect to any Company Plan. The Company and
  each of the Company Subsidiaries has not incurred any liability for any
  excise tax arising under Section 4972 or 4980B of the Code and, to the
  knowledge of Company or the Company Subsidiaries, no fact or event exists
  that could give rise to any such liability.
 
    (d) Plan Contributions. All contributions, provisions or payments
  required to be made with respect to any Company Plan have been made on or
  before their due dates.
 
  Section 3.11 Registration Statement; Proxy Statement/Prospectus. The
information supplied by the Company for inclusion in the registration
statement of the Company (the "Registration Statement") pursuant to which the
shares of Company Common Stock to be issued in the Merger will be registered
with the SEC shall not, at the time the Registration Statement (including any
amendments or supplements thereto) is declared effective by the SEC, 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 were made, not
misleading. The information supplied by the Company for inclusion in the Proxy
Statement/Prospectus shall not, at the date the Proxy Statement/Prospectus (or
any amendment thereof or supplement thereto) is first mailed to shareholders,
at the time of the Seller's Shareholders' Meeting and at the Effective Time,
be false or misleading with respect to any material fact required to be stated
therein, or omit to state any material fact necessary in order to make the
statements made therein, in light of the circumstances under which they are
made, not misleading. If at any time prior to the Effective Time any event
relating to the Company or any of its affiliates, officers or directors should
be discovered by the Company which should be set forth in an amendment to the
Registration Statement or a supplement to the Proxy Statement/Prospectus, the
Company will promptly inform the Seller. The Registration Statement and the
Proxy Statement/Prospectus shall comply in all material respects as to form
with the requirements of the Securities Act, the Exchange Act and the rules
and regulations thereunder. Notwithstanding the foregoing, the Company makes
no representation or warranty with respect to any information about, or
supplied or omitted by, Seller which is contained in any of the foregoing
documents.
 
  Section 3.12 Title to Property. The Company and each of the Company
Subsidiaries has good and marketable title to all of their respective
properties and assets, real and personal, free and clear of all mortgage
liens, and free and clear of all other liens, charges and encumbrances except
liens for taxes not yet due and payable, pledges to secure deposits and such
minor imperfections of title, if any, as do not materially detract from the
value of or interfere with the present use of the property affected thereby or
which, individually or in the aggregate, would not have a Material Adverse
Effect on the Company and the Company Subsidiaries, taken as a whole; and all
leases pursuant to which the Company or any of the Company Subsidiaries lease
from others material amounts of real or personal property are in good
standing, valid and effective in accordance with their respective terms, and
there is not, under any of such leases, any existing material default or event
of default (or event which with notice or lapse of time, or both, would
constitute a material default and in respect of which the Company or such
subsidiary has not taken adequate steps to prevent such a default from
occurring). Substantially all of the Company's and each of the Company
Subsidiaries' buildings and equipment in regular use have been reasonably
maintained and are in good and serviceable condition, reasonable wear and tear
excepted.
 
  Section 3.13 Absence of Agreements. Neither the Company nor any of the
Company Subsidiaries is a party to any agreement or memorandum of
understanding with, or a party to any commitment letter or similar undertaking
to, or is subject to any order or directive by, or is a recipient of any
extraordinary supervisory letter which restricts materially the conduct of its
business (including any contract containing covenants which limit the ability
of the Company or Company Subsidiary to compete in any line of business or
with any person or which involve any restriction of the geographical area in
which, or method by which, the Company or any
 
                                     A-20
<PAGE>
 
Company Subsidiary may carry on its business (other than as may be required by
Law or applicable regulatory authorities)), in any manner relates to its
capital adequacy, its credit policies, or its management, except for those the
existence of which has been disclosed to Seller prior to the date of this
Agreement, nor has the Company been advised that any federal, state, or
governmental agency is contemplating issuing or requesting (or is considering
the appropriateness of issuing or requesting) any such order, decree,
agreement, memorandum of understanding, extraordinary supervisory letter,
commitment letter or similar submission, except as disclosed by the Company in
Section 3.14 of the Company Disclosure Schedule.
 
  Section 3.14 Taxes. The Company and the Company Subsidiaries have timely
filed all Material Tax Returns (as defined below) required to be filed by
them, and Company and the Company Subsidiaries have timely paid and discharged
all Material Taxes (as defined below) due in connection with or with respect
to the filing of such Tax Returns and have timely paid all other Taxes as are
due, except such as are being contested in good faith by appropriate
proceedings and with respect to which Seller is maintaining reserves adequate
for their payment. For purposes of this Agreement, "Tax" or "Taxes" shall mean
taxes, charges, fees, levies, and other governmental assessments and
impositions of any kind, payable to any federal, state, local or foreign
governmental entity or taxing authority or agency, including, without
limitation, (i) income, franchise, profits, gross receipts, estimated, ad
valorem, value added, sales, use, service, real or personal property, capital
stock, license, payroll, withholding, disability, employment, social security,
workers compensation, unemployment compensation, utility, severance,
production, excise, stamp, occupation, premiums, windfall profits, transfer
and gains taxes, (ii) customs duties, imposts, charges, levies or other
similar assessments of any kind, and (iii) interest, penalties and additions
to tax imposed with respect thereto; and "Tax Returns" shall mean returns,
reports, and information statements with respect to Taxes required to be filed
with the IRS or any other governmental entity or taxing authority or agency,
domestic or foreign, including, without limitation, consolidated, combined and
unitary tax returns. Except as otherwise disclosed, to the best knowledge of
the Company, neither the IRS nor any other governmental entity or taxing
authority or agency is now asserting, either through audits, administrative
proceedings or court proceedings, any deficiency or claim for additional
Taxes. Except as otherwise disclosed, neither Company nor any of the Company's
Subsidiaries has granted any waiver of any statute of limitations with respect
to, or any extension of a period for the assessment of, any Tax. Except as
otherwise disclosed and except for statutory liens for current taxes not yet
due, there are no material tax liens on any assets of Company or any of the
Company Subsidiaries. Except as otherwise disclosed neither Company nor any of
the Company Subsidiaries has received a ruling or entered into an agreement
with the IRS or any other taxing authority that would have a Material Adverse
Effect on Company and the Company Subsidiaries, taken as a whole, after the
Effective Time. The accruals and reserves for taxes reflected in the Seller
Balance Sheet are adequate to cover all Taxes accruable through the date
thereof (including Taxes being contested) in accordance with generally
accepted accounting principles. Except as otherwise disclosed, no agreements
relating to allocating or sharing of Taxes exist among Company and the Company
Subsidiaries. Neither Company nor any of the Company Subsidiaries has made an
election under Section 341(f) of the Code.
 
  Section 3.15 Brokers. No broker, finder or investment banker (other than
Salomon Brothers, Inc.) is entitled to any brokerage, finder's or other fee or
commission in connection with the transactions contemplated by this Agreement
based upon arrangements made by or on behalf of the Company. Prior to the date
of this Agreement, the Company has furnished Seller a complete and correct
copy of all agreements between the Company and Salomon Brothers Inc. pursuant
to which such firm would be entitled to any payment relating to the
transactions contemplated hereunder.
 
  Section 3.16 Tax Matters. Neither the Company nor, to the Company's
knowledge, any of its affiliates has through the date of this Agreement taken
or agreed to take any action that would prevent the Merger from qualifying as
a reorganization under Section 368(a)(1)(A) of the Code.
 
  Section 3.17 Material Adverse Effect. Since December 31, 1996 there has been
no Material Adverse Effect on the Company and the Company Subsidiaries, taken
as a whole.
 
 
                                     A-21
<PAGE>
 
                        ARTICLE IV--COVENANTS OF SELLER
 
  Section 4.1 Affirmative Covenants. Seller hereby covenants and agrees with
the Company that prior to the Effective Time, unless the prior written consent
of the Company shall have been obtained and except as otherwise contemplated
herein, it will and it will cause each Seller Subsidiary to:
 
    (a) operate its business only in the ordinary course consistent with past
  practices;
 
    (b) use all reasonable efforts to preserve intact its business
  organization and assets, maintain its rights and franchises, retain the
  services of its officers and key employees and maintain its relationships
  with customers;
 
    (c) use all reasonable efforts to maintain and keep its properties in as
  good repair and condition as at present, ordinary wear and tear excepted;
 
    (d) use all reasonable efforts to keep in full force and effect insurance
  and bonds comparable in amount and scope of coverage to that now maintained
  by it;
 
    (e) use all reasonable efforts to perform in all material respects all
  obligations required to be performed by it under all material contracts,
  leases, and documents relating to or affecting its assets, properties, and
  business; and
 
    (f) take such reasonable actions as are requested by the Company to
  complete the Merger and the Bank Merger, including but not limited to (i)
  amending the Articles of Incorporation of Seller's Bank Subsidiary, (ii)
  causing Seller's Bank Subsidiary to enter into an agreement documenting the
  terms and conditions of the Bank Merger (the "Bank Merger Agreement") and
  (iii) approving the Bank Merger and Bank Merger Agreement as sole
  shareholder of Seller's Bank Subsidiary.
 
  Section 4.2 Negative Covenants. Except as specifically contemplated by this
Agreement, from the date of this Agreement until the Effective Time, Seller
shall not do, or permit any Seller Subsidiary to do, without the prior written
consent of the Company, any of the following:
 
    (a) (i) except as required by applicable law or to maintain qualification
  pursuant to the Code, adopt, amend, renew or terminate any Plan or any
  agreement, arrangement, plan or policy between the Seller or any Subsidiary
  of the Seller and one or more of its current or former directors, officers
  or employees or (ii) except for normal increases in the ordinary course of
  business consistent with past practice, and subject to the specific
  provisions of Annex B, or, except as required by applicable law, increase
  in any manner the base salary, bonus incentive compensation or fringe
  benefits of any director, officer or employee or pay any benefit not
  required by any plan or agreement as in effect as of the date hereof
  (including, without limitation, the granting of stock options, stock
  appreciation rights, restricted stock, restricted stock units or
  performance units or shares);
 
    (b) (i) except as provided below declare or pay any dividend on, or make
  any other distribution in respect of, its outstanding shares of capital
  stock, except for (A) regular quarterly cash dividends on Seller Common
  Stock with usual record and payment dates for such dividends with each such
  dividend at a rate per share of Seller Common Stock not in excess of $.30
  and (B) dividends by a Seller Subsidiary to Seller;
 
    (ii) declare or pay any dividends or make any distributions in any amount
  on Seller Common Stock in or with respect to the quarter in which the
  Effective Time shall occur and in which the shareholders of Seller Common
  Stock are entitled to receive dividends on the shares of Company Common
  Stock into which the shares of Seller Common Stock have been converted;
  provided that, it is the intent of this clause (ii) to provide that the
  holders of Seller Common Stock will receive either the payment of cash
  dividends on their shares of Seller Common Stock or the payment of cash
  dividends as the holders of shares of Company Common Stock received in
  exchange for the shares of Seller Common Stock pursuant to this Agreement
  for the calendar quarter during which the Effective Time shall occur, but
  will not receive and will not become entitled to receive for the same
  calendar quarter both the payment of a cash dividend as shareholders of
  Seller Common Stock and the payment of a cash dividend as the holders of
  shares of Company Common Stock received in exchange for the shares of
  Seller Common Stock pursuant to this Agreement; and if Seller does not
  declare and pay cash dividends in a particular calendar quarter because of
  Seller's reasonable
 
                                     A-22
<PAGE>
 
  expectation that the Effective Time was to have occurred in such calendar
  quarter wherein the holders of Seller Common Stock would have become
  entitled to receive cash dividends for such calendar quarter on the shares
  of Company Common Stock to have been exchanged for the shares of Seller
  Common Stock pursuant to this Agreement, and the Effective Time does not in
  fact occur in such calendar quarter, then, as a result thereof, Seller
  shall be entitled to declare and pay a cash dividend (within the
  limitations of this clause (ii)) on such shares of Seller Common Stock for
  such calendar quarter by the declaration and payment of such cash dividends
  as soon as reasonably practicable after the end of such calendar quarter;
 
    (c)(i) redeem, purchase or otherwise acquire any shares of its capital
  stock or any securities or obligations convertible into or exchangeable for
  any shares of its capital stock, or any options, warrants, conversion or
  other rights to acquire any shares of its capital stock or any such
  securities or obligations; (ii) merge with or into any other corporation or
  bank, permit any other corporation or bank to merge into it or consolidate
  with any other corporation or bank, or effect any reorganization or
  recapitalization; (iii) purchase or otherwise acquire any substantial
  portion of the assets, or more than 5% of any class of stock, of any
  corporation, bank or other business other than in the ordinary course of
  business and consistent with past practice; (iv) liquidate, sell, dispose
  of, or encumber any assets or acquire any assets, other than in the
  ordinary course of its business consistent with past practice; or (v)
  split, combine or reclassify any of its 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 its capital stock;
 
    (d) issue, deliver, award, grant or sell, or authorize or propose the
  issuance, delivery, award, grant or sale of, any shares of any class of
  capital stock of Seller or any Seller Subsidiary (including shares held in
  treasury) or any rights, warrants or options to acquire, any such shares,
  other than the issuance of Seller Common Stock issuable upon exercise of
  employee stock options outstanding as of the date of this Agreement or
  pursuant to Seller Plans, in effect as of the date of this Agreement;
 
    (e) authorize or permit any of its officers, directors, employees or
  agents to directly or indirectly solicit, initiate or encourage any
  inquiries relating to, or the making of any proposal which constitutes, a
  "takeover proposal" (as defined below), or (i) recommend or endorse any
  takeover proposal, (ii) participate in any discussions or negotiations with
  respect to a takeover proposal, or (iii) provide third parties with any
  nonpublic information relating to any such inquiry or proposal; provided,
  however, that the Seller may, and may authorize and permit its officers,
  directors, employees or agents to, provide third parties with nonpublic
  information, otherwise facilitate any effort or attempt by any third party
  to make or implement a takeover proposal, recommend or endorse any takeover
  proposal with or by any third party, and participate in discussions and
  negotiations with any third party relating to any takeover proposal, if
  such party's Board of Directors, after having consulted with and considered
  the advice of outside counsel, has determined in good faith that such
  actions are necessary for the discharge of the fiduciary duties of the
  Seller's Board of Directors. The Seller will immediately cease and cause to
  be terminated any existing activities, discussions or negotiations
  previously conducted with any parties other than Company with respect to
  any of the foregoing. The Seller will take all actions necessary or
  advisable to inform the appropriate individuals or entities referred to in
  the first sentence hereof of the obligations undertaken in this Section
  4.2(e). The Seller will notify Company immediately if any such inquiries or
  takeover proposals are received by, any such information is requested from,
  or any such negotiations or discussions are sought to be initiated or
  continued with, the Seller. As used in this Agreement, "takeover proposal"
  shall mean any tender or exchange offer, proposal for a merger,
  consolidation or other business combination involving the Seller or any
  Seller Subsidiary or any proposal or offer to acquire in any manner a
  substantial equity interest in, or a substantial portion of the assets of,
  the Seller or any Seller Subsidiary other than the transactions
  contemplated or permitted by this Agreement;
 
    (f) propose or adopt any amendments to its articles of incorporation or
  by-laws in any way adverse to the Company;
 
    (g) change any of its methods of accounting in effect at June 30, 1996,
  or change any of its methods of reporting income or deductions for federal
  income tax purposes from those employed in the preparation of
 
                                     A-23
<PAGE>
 
  the federal income tax returns for the taxable year ending December 31,
  1996, except as may be required by Law or generally accepted accounting
  principles;
 
    (h) change in any material respect any lending, investment, liability
  management or other material policies concerning the business or operations
  of Seller or any of the Seller Subsidiaries, except as required by Law,
  including, without limitation: (i) acquire or sell any contracts for the
  purchase or sale of financial or other futures or any put or call options,
  or enter into any hedges or interest rate swaps relating to cash,
  securities, or any commodities whatsoever or enter into any other
  derivative transaction; (ii) except for transactions disclosed in Section
  2.13 of the Seller Disclosure Schedule, sell, assign, transfer, pledge,
  mortgage or otherwise encumber, or permit any encumbrances to exist with
  respect to, any of its assets with a value in excess of $100,000
  individually, except in the ordinary course of business consistent with
  past practice; (iii) make any investment with an interest maturity of five
  years or more except in the ordinary course of business consistent with
  past practice; (iv) incur any material liabilities or material obligations,
  whether directly or by way of guaranty, including any obligation for
  borrowed money, whether or not evidenced by a note, bond, debenture or
  similar instrument, except in the ordinary course of business consistent
  with past practice and in no event in excess of $100,000 individually; (v)
  enter into any agreement with respect to any acquisition of a material
  amount of assets or securities or any discharge, waiver, satisfaction,
  release or relinquishment of any material contract rights, liens,
  encumbrances, debt or claims, not in the ordinary course of business and
  consistent with past practices and in no event with a value in excess of
  $200,000 individually; (vi) settle any claim, action, suit, litigation,
  proceeding, arbitration, investigation or controversy of any kind, for any
  amount in excess of $250,000, net of any insurance proceeds, or in any
  manner which would restrict in any material respect the operations or
  business of Seller or any of the Seller Subsidiaries; (vii) make any
  capital expenditure, except in the ordinary course and consistent with past
  practice and in no event in excess of $100,000 individually; or (viii) take
  any action or fail to take any action which individually or in the
  aggregate can be expected to have a Material Adverse Effect on the Seller
  and the Seller Subsidiaries, taken as a whole; and,
 
    (i) agree in writing or otherwise to do any of the foregoing.
 
  Section 4.3 Letter of Seller's Accountants. Seller shall use its reasonable
best efforts to cause to be delivered to the Company "comfort" letters of KPMG
Peat Marwick, LLP, Seller's independent public accountants, dated the date on
which the Registration Statement shall become effective and the Effective
Time, respectively, and addressed to the Company, in a form reasonably
satisfactory to the Company and reasonably customary in scope and substance
for letters delivered by independent public accountants in connection with
registration statements similar to the Registration Statement and transactions
such as those contemplated by this Agreement.
 
  Section 4.4 Access and Information.
 
    (a) Until the Effective Time and upon reasonable notice, and subject to
  applicable laws relating to the exchange of information, the Seller shall,
  and shall cause each Seller Subsidiary to, afford to the Company's
  officers, employees, accountants, legal counsel and other representatives
  of Company, access, during normal business hours, to all its properties,
  books, contracts, commitments and records. Prior to the Effective Time,
  Seller shall (and shall cause each Seller Subsidiary to) furnish promptly
  (as soon as available or received by Seller or any Seller Subsidiary) to
  the Company (i) a copy of each Seller Report filed by it or received by it
  (to the extent not prohibited by Law and if so prohibited the Seller shall
  promptly so notify the Company) after the date of this Agreement and prior
  to the Effective Time pursuant to the requirements of federal or state
  securities laws, the BHCA, any other federal or state banking laws or any
  other applicable Laws promptly after such documents are available, (ii) the
  monthly financial statements of Seller and the Seller Subsidiaries (as
  prepared by Seller in accordance with its normal accounting procedures)
  promptly after such financial statements are available without further
  request by the Company, (iii) a copy of any action, including all minutes,
  taken by the Board of Directors, or any committee thereof, of Seller and
  the Seller Subsidiaries and any documents or other materials of any kind
  provided to such Boards or Committees promptly after such action, minutes,
  materials or other documents become available without further request
 
                                     A-24
<PAGE>
 
  by the Company, (iv) a copy of each Tax Return filed by Seller and each
  Seller Subsidiary for the three most recent years available, a copy of any
  correspondence received from the IRS or any other governmental entity or
  taxing authority or agency and any other correspondence relating to Taxes,
  and any other documents relating to Taxes as the Company may reasonably
  request, and (v) all other information concerning its business, properties
  and personnel as Company may reasonably request, other than in each case
  reports or documents which Seller is not permitted to disclose under
  applicable law or binding agreement entered into prior to the date of this
  Agreement. The parties hereto will make appropriate substitute disclosure
  arrangements under circumstances in which the restrictions of the preceding
  sentence apply.
 
    (b) Unless otherwise required by Law, the parties will hold any such
  information which is nonpublic in confidence in accordance with the terms
  of the confidentiality agreements in effect between the parties on the date
  of this Agreement.
 
  Section 4.5 Update Disclosure; Breaches.
 
    (a) From and after the date of this Agreement until the Effective Time,
  Seller shall update the Seller Disclosure Statement on a regular basis by
  written notice to the Company to reflect any matters which have occurred
  from and after the date of this Agreement which, if existing on the date of
  this Agreement, would have been required to be described therein; provided
  that, without limiting the Company's rights under Section 4.4, (i) to the
  extent that any information that would be required to be included in an
  update under this Section 4.5(a) would have in the past been contained in
  internal reports prepared by Seller or any Seller Subsidiary in the
  ordinary course, such update may occur by delivery of such internal reports
  prepared in accordance with past practice, with appropriate steps taken by
  Seller to identify relevant information contained therein, and (ii) to the
  extent that updating required under this Section is unduly burdensome to
  Seller, Seller and the Company will use their best efforts to develop
  alternate updating procedures utilizing, wherever possible, existing
  reporting systems.
 
    (b) Seller shall, in the event it becomes aware of the impending or
  threatened occurrence of any event or condition which would cause or
  constitute a material breach (or would have caused or constituted a
  material breach had such event occurred or been known prior to the date of
  this Agreement) of any of its representations or agreements contained or
  referred to herein, give prompt written notice thereof to the Company and
  use its best efforts to prevent or promptly remedy the same.
 
  Section 4.6 Affiliates; Tax Treatment. Within thirty (30) days after the
date of this Agreement, (a) Seller shall deliver to the Company a letter
identifying all persons who are then "affiliates" of Seller, including,
without limitation, all directors and executive officers of Seller, for
purposes of Rule 145 promulgated under the Securities Act (each a "Seller
Affiliate") and (b) Seller shall advise the persons identified in such letter
of the resale restrictions imposed by applicable securities laws and shall use
reasonable efforts to obtain from each person identified by mutual agreement
of the parties, such letter to be in a form mutually agreed to by the parties.
Seller shall use its reasonable best efforts to obtain from any person who
becomes an affiliate of Seller after Seller's delivery of the letter referred
to above, and on or prior to the Effective Time, a written agreement
substantially in such form as soon as practicable after attaining such status.
Seller will use its reasonable best efforts to cause the Merger to qualify as
a reorganization under Section 368(a)(1)(A) of the Code.
 
  Section 4.7 Expenses.
 
    (a) All Expenses (as defined below) incurred by the Company and Seller
  shall be borne solely and entirely by the party which has incurred the
  same, except that the parties shall share equally in the expense of
  printing and filing the Registration Statement and the Proxy
  Statement/Prospectus and all SEC and other regulatory filing fees incurred
  in connection herewith. Notwithstanding the foregoing, the Company shall
  reimburse Seller for all direct or indirect costs and expenses incurred by
  Seller related to the Data Processing Conversion (including without
  limitation any cost related to write-offs, hardware, employee layoffs,
  equipment purchases and contract termination costs).
 
 
                                     A-25
<PAGE>
 
    (b) "Expenses" as used in this Agreement shall include all reasonable
  out-of-pocket expenses (including, without limitation, all fees and
  expenses of counsel, accountants, investment bankers, experts and
  consultants to the party and its affiliates) incurred by a party or on its
  behalf in connection with or related to the authorization, preparation and
  execution of this Agreement, the solicitation of shareholder approvals and
  all other matters related to the closing of the transactions contemplated
  hereby.
 
  Section 4.8 Delivery of Shareholder List. Seller shall arrange to have its
transfer agent deliver to the Company or its designee, from time to time prior
to the Effective Time, a true and complete list setting forth the names and
addresses of the Seller shareholders, their holdings of stock as of the latest
practicable date, and such other shareholder information as the Company may
reasonably request.
 
  Section 4.9 Loan and Investment Policies. To the extent permitted by
applicable law or regulations, the Company and Seller agree to establish,
within 30 days of the date of this Agreement at Seller's Bank and any Seller
Subsidiaries which make loans, loan and investment policies and procedures
designed to insure safe and sound banking practices, which shall remain in
effect, except as otherwise agreed in writing by the Company, for the period
prior to the Effective Time. To the extent permitted by applicable law or
regulations, such policies and procedures shall apply to, among other matters,
the following: (i) making or renewing any commitments or loans, or purchase or
renewals of any participations in loans, in excess of an amount to be agreed
upon; (ii) making, committing to make or renewing any loan to any affiliate of
Seller or the Seller Subsidiaries or any family member of such affiliate or
any entity in which such affiliate has a material interest; (iii) making any
investment or commitment to invest, or making any loan, in excess of an amount
to be agreed with respect to any commercial real estate or in or with respect
to any commercial real estate development project; or (iv) entering into any
contract, lease, or license under which Seller or any Seller Subsidiary will
be bound to pay in excess of an amount to be agreed over the life of such
agreement or voluntarily committing any act or omission which constitutes a
breach or default by Seller or any Seller Subsidiary under any material
contract, lease or license to which Seller or any Seller Subsidiary is a party
or by which it or any of its properties are bound. To the extent permitted by
applicable law or regulations, the Company shall have the right to designate
at least two (2) observers to attend all meetings of Seller's (i) Senior
Credit Committee, or similar committee at any Seller Subsidiary designated by
the Company, and (ii) investment committee or similar committee at any Seller
Subsidiary, and Seller shall ensure that such representatives receive all
information given by Seller or its agents to Seller's members of said
committees.
 
                      ARTICLE V--COVENANTS OF THE COMPANY
 
  Section 5.1 Affirmative Covenants. The Company hereby covenants and agrees
with Seller that prior to the Effective Time, unless the prior written consent
of Seller shall have been obtained and except as otherwise contemplated
herein, it will:
 
    (a) maintain its corporate existence in good standing and maintain all
  books and records in accordance with accounting principles and practices as
  utilized in the Company's financial statements applied on a consistent
  basis; and
 
    (b) conduct its business in a manner that does not violate any Law,
  except for possible violations which individually or in the aggregate do
  not, and, insofar as reasonably can be foreseen, in the future will not,
  have a Material Adverse Effect on the Company and the Company Subsidiaries,
  taken as a whole.
 
  Section 5.2 Negative Covenants. Except as set forth in Section 5.2 of the
Company Disclosure Schedule or as otherwise contemplated by this Agreement,
from the date of this Agreement until the Effective Time, the Company shall
not do, or agree to commit to do, or permit any of its subsidiaries to do,
without the prior written consent of Seller any of the following:
 
    (a) solely in the case of Company, declare or pay any extraordinary or
  special dividends on or make any other extraordinary or special
  distributions in respect of any of its capital stock; provided, however,
 
                                     A-26
<PAGE>
 
  that nothing contained herein shall prohibit Company from increasing the
  quarterly cash dividend on the Company Common Stock;
 
    (b) take any action that is intended or may reasonably be expected to
  result in any of its representations and warranties set forth in this
  Agreement being or becoming untrue in any material respect, or in any of
  the conditions to the Merger set forth in Article VII not being satisfied,
  or in a violation of any provision of this Agreement or the Bank Merger
  Agreement except, in every case, as may be required by applicable law;
 
    (c) take or cause to be taken any action which would disqualify the
  Merger as a tax free reorganization under Section 368 of the Code;
 
    (d) amend its Articles of Incorporation or By-laws or other governing
  instrument in a manner which would adversely affect in any manner the terms
  of the Company Common Stock or the ability of Company to consummate the
  transactions contemplated hereby;
 
    (e) enter into any agreement providing for, or otherwise participate in,
  any merger, consolidation or other transaction in which the Company or any
  surviving corporation would be required not to consummate the Merger or any
  of the other transactions contemplated hereby in accordance with the terms
  of this Agreement, as the case may be; or
 
    (f) agree to do any of the foregoing.
 
  Section 5.3 Access and Information.
 
    (a) Until the Effective Time and upon reasonable notice and subject to
  applicable laws relating to the exchange of information, Company shall, and
  shall cause each Company Subsidiary to, afford to the Seller's officers,
  employees, accountants, legal counsel and other representatives of the
  Seller, access, during normal business hours, to all its properties, books,
  contracts, commitments and records. Prior to the Effective Time, Company
  shall (and shall cause each Company Subsidiary to) furnish promptly (as
  soon as available or received by Company or any Company Subsidiary) to the
  Seller (i) a copy of each Company Report filed by it or received by it (to
  the extent not prohibited by Law and if so prohibited, the Company shall
  promptly so notify the Seller) after the date of this Agreement and prior
  to the Effective Time pursuant to the requirements of federal or state
  securities laws, the BHCA, any other federal or state banking laws or any
  other applicable Laws promptly after such documents are available and (ii)
  all other information concerning the business, properties and personnel of
  the Company or the Company Subsidiaries as Seller may reasonably request,
  other than in each case reports or documents which the Company is not
  permitted to disclose under applicable law or binding agreement entered in
  to prior to the date of this Agreement. The parties hereto will make
  appropriate substitute disclosure arrangements under circumstances in which
  the restrictions of the preceding sentence apply.
 
    (b) Unless otherwise required by Law, the parties will hold any such
  information which is nonpublic in confidence pursuant to the terms of the
  confidentiality agreements in effect between the parties on the date of
  this Agreement.
 
  Section 5.4 Breaches. The Company shall, in the event it becomes aware of
the impending or threatened occurrence of any event or condition which would
cause or constitute a material breach (or would have caused or constituted a
material breach had such event occurred or been known prior to the date of
this Agreement) of any of its representations or agreements contained or
referred to herein, give prompt written notice thereof to the Seller and use
its best efforts to prevent or promptly remedy the same.
 
  Section 5.5 Stock Exchange Listing. The Company shall use all reasonable
efforts to cause the shares of Company Common Stock to be issued in the Merger
to be approved for listing on the NASDAQ/NMS prior to the Effective Time.
 
  Section 5.6 Tax Treatment. The Company will use its reasonable best efforts
to cause the Merger to qualify as a reorganization under Section 368(a)(1)(A)
of the Code.
 
                                     A-27
<PAGE>
 
  Section 5.7 Stock Options. (a) At the Effective Time, each option treated as
an ISO granted by the Seller (a "Seller Option") to purchase shares of Seller
Common Stock which is outstanding and unexercised immediately prior thereto
shall be converted automatically into an option to purchase shares of Company
Common Stock in an amount and at an exercise price determined as provided
below (and otherwise subject to the terms of the Seller's 1993 Incentive Stock
Option Plan and 1993 Stock Option Plan for Outside Directors (the "Option
Plans")).
 
    (i) The number of shares of Company Common Stock to be subject to the new
  option shall be equal to the product of the number of shares of Seller
  Common Stock subject to the original option and the Per Share Stock
  Consideration, provided that any fractional shares of Company Common Stock
  resulting from such multiplication shall be rounded down to the nearest
  share; and
 
    (ii) The exercise price per share of Company Common Stock under the new
  option shall be equal to the exercise price per share of Seller Common
  Stock under the original option divided by the Per Share Stock
  Consideration, provided that such exercise price shall be rounded up to the
  nearest cent.
 
  The adjustment provided herein with respect to any options which are ISOs
shall be and is intended to be effected in a manner which is consistent with
Section 424(a) of the Code. The duration and other terms of the new option
shall be the same as the original option, except that all references to the
Seller shall be deemed to be references to Company.
 
  (b) Within five days after the Effective Time, Company shall file with the
SEC a registration statement on an appropriate form under the Securities Act
with respect to the shares of Company Common Stock subject to options to
acquire Company Common Stock issued pursuant to Section 5.7(a) hereof, and
shall use its best efforts to maintain the current status of the prospectus
contained therein, as well as comply with applicable state securities or "blue
sky" laws, for so long as such options remain outstanding.
 
                       ARTICLE VI--ADDITIONAL AGREEMENTS
 
  Section 6.1 Proxy Statement/Prospectus; Registration Statement. As promptly
as practicable after the execution of this Agreement, Seller and the Company
shall prepare and file with the SEC the Proxy Statement/Prospectus and
registration statement on Form S-4 promulgated under the Securities Act and
the Exchange Act (or on such other form as shall be appropriate) relating to
the approval of the Merger by the shareholders of Seller and shall use all
reasonable efforts to cause the Registration Statement to become effective as
soon thereafter as practicable. The Proxy Statement/Prospectus shall include
the recommendation of the Board of Directors of Seller in favor of the Merger,
unless the Board of Directors of Seller shall have determined in good faith
based on advice of counsel that such recommendation would violate its
fiduciary duty to Seller's Shareholders.
 
  Section 6.2 Meeting of Seller's Shareholders. Seller shall promptly after
the date of this Agreement take all action necessary in accordance with the
WBCL and the Seller Articles and the Seller By-Laws to convene the Seller
Shareholders' Meeting. Seller shall use its best efforts to solicit from
shareholders of Seller proxies in favor of the Merger and shall take all other
action necessary or advisable to secure the vote or consent of shareholders
required by the WBCL to approve the Merger, unless the Board of Directors of
Seller shall have determined in good faith based on advice of counsel that
such actions would violate its fiduciary duty to Seller's Shareholders.
 
  Section 6.3 Appropriate Action; Consents; Filings. Seller and the Company
shall use all reasonable efforts to (i) take, or cause to be taken, all
appropriate action, and do, or cause to be done, all things necessary, proper
or advisable under applicable Law to consummate and make effective the
transactions contemplated by this Agreement, (ii) obtain all consents,
licenses, permits, waivers, approvals, authorizations or orders required
 
                                     A-28
<PAGE>
 
under Law (including, without limitation, all foreign and domestic (federal,
state and local) governmental and regulatory rulings and approvals and parties
to contracts) required in connection with the authorization, execution and
delivery of this Agreement and the consummation by them of the transactions
contemplated hereby, including, without limitation, the Merger, (iii) make all
necessary filings, and thereafter make any other required submissions, with
respect to this Agreement, the Merger required under (A) the Securities Act
and the Exchange Act and the rules and regulations thereunder, and any other
applicable federal or state securities laws, (B) the BHCA, the WBL and any
other applicable federal or state banking laws and (C) any other applicable
Law; provided that, the Company and Seller shall cooperate with each other in
connection with the making of all such filings, including providing copies of
all such documents to the non-filing party and its advisors prior to filing
and, if requested, to accept all reasonable additions, deletions or changes
suggested in connection therewith. Seller and the Company shall furnish all
information required for any application or other filing to be made pursuant
to the rules and regulations of any applicable Law (including all information
required to be included in the Proxy Statement/Prospectus and the Registration
Statement) in connection with the transactions contemplated by this Agreement.
In case at any time after the Effective Time any further action is necessary
or desirable to carry out the purposes of this Agreement, the proper officers
and directors of each party to this Agreement shall use all reasonable efforts
to take all such necessary action.
 
  Section 6.4 Employee Stock Options and Other Employee Benefit Matters. Annex
B hereto sets forth certain agreements with respect to Seller's employee stock
options and other employee benefit matters.
 
  Section 6.5 Directors' and Officers' Indemnification and Insurance.
 
    (a) In the event of any threatened or actual claim, action, suit,
  proceeding or investigation, whether civil, criminal or administrative,
  including, without limitation, any such claim, action, suit, proceeding or
  investigation in which any person who is now, or has been at any time prior
  to the date of this Agreement, or who becomes prior to the Effective Time,
  a director, officer or employee of the Seller or any of its Subsidiaries
  (including in his/her role as a fiduciary of the employee benefit plans of
  the Seller, if applicable) (the "Indemnified Parties") is, or is threatened
  to be, made a party based in whole or in part on, or arising in whole or in
  part out of, or pertaining to (i) the fact that he is or was a director,
  officer or employee of the Seller, any of the Seller Subsidiaries or any of
  their respective predecessors or (ii) this Agreement or any of the
  transactions contemplated hereby, whether in any case asserted or arising
  before or after the Effective Time, the parties hereto agree to cooperate
  and use their best efforts to defend against and respond thereto. It is
  understood and agreed that after the Effective Time, Company shall
  indemnify and hold harmless, to the fullest extent permitted by law, each
  such Indemnified Party against any losses, claims, damages, liabilities,
  costs, expenses (including reasonable attorney's fees and expenses in
  advance of the final disposition of any claim, suit, proceeding or
  investigation to each Indemnified Party to the fullest extent permitted by
  law upon receipt of any undertaking required by applicable law), judgments,
  fines and amounts paid in settlement in connection with any such threatened
  or actual claim, action, suit, proceeding or investigation, and in the
  event of any such threatened or actual claim, action, suit, proceeding or
  investigation (whether asserted or arising before or after the Effective
  Time), the Indemnified Parties may retain counsel satisfactory to them
  after consultation with Company; provided, however, that the (1) Company
  shall have the right to assume the defense thereof and upon such assumption
  Company shall not be liable to any Indemnified Party for any legal expenses
  of other counsel or any other expenses subsequently incurred by any
  Indemnified Party in connection with the defense thereof, except that if
  Company elects not to assume such defense or counsel for the Indemnified
  Parties reasonably advises that there are issues which raise conflicts of
  interest between Company and the Indemnified Parties, the Indemnified
  Parties may retain counsel satisfactory to them after consultation with
  Company, and Company shall pay the reasonable fees and expenses of such
  counsel for the Indemnified Parties, (2) Company shall in all cases be
  obligated pursuant to this paragraph to pay for only one firm of counsel
  for all Indemnified Parties, (3) Company shall not be liable for any
  settlement effected without its prior written consent (which consent shall
  not be unreasonably withheld) and (4) Company shall have no obligation
  hereunder to any Indemnified Party when and if a court of competent
  jurisdiction shall ultimately determine, and such determination shall have
  become final and nonappealable; that indemnification of such Indemnified
  Party in
 
                                     A-29
<PAGE>
 
  the manner contemplated hereby is prohibited by applicable law. Any
  Indemnified Party wishing to claim indemnification under this Section 6.5,
  upon learning of any such claim, action, suit, proceeding or investigation,
  shall promptly notify Company thereof, provided that the failure to so
  notify shall not affect the obligations of Company under this Section 6.5
  except to the extent such failure to notify materially prejudices Company.
  Company's obligations under this Section 6.5 shall continue in full force
  and effect for a period of six (6) years from the Effective Time; provided,
  however, that all rights to indemnification in respect of any claim (a
  "Claim") asserted or made within such period shall continue until the final
  disposition of such Claim.
 
    (b) Prior to the Effective Time the Seller shall purchase, and for a
  period of six (6) years after the Effective Time, Company shall use its
  best efforts to maintain, directors and officers liability insurance "tail"
  or "runoff" coverage with respect to wrongful acts and/or omissions
  committed or allegedly committed prior to the Effective Time. Such coverage
  shall have an aggregate coverage limit over the term of such policy in an
  amount no less than the annual aggregate coverage limit under the Seller's
  existing directors and officers liability policy, and in all other respects
  shall be at least comparable to such existing policy provided, however,
  that in no event shall Company be required to expend on an annual basis
  more than 200% of the current amount expended by the Seller (the "Insurance
  Amount") to maintain or procure insurance coverage, and further provided
  that if Company is unable to maintain or obtain the insurance called for by
  this Section 6.5 Company shall use all reasonable efforts to obtain as much
  comparable insurance as available for the Insurance Amount.
 
    (c) In the event Company or the Surviving Corporation 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 or conveys all or substantially
  all of its properties and assets to any person, then, and in each such
  case, proper provision shall be made so that the successors and assigns of
  Company or the Surviving Corporation, as the case may be, assume the
  obligations set forth in this section.
 
    (d) The provisions of this Section 6.5 are intended to be for the benefit
  of, and shall be enforceable by, each Indemnified Party and his or her
  heirs and representatives.
 
  Section 6.6 Notification of Certain Matters. Seller shall give prompt notice
to the Company, and the Company shall give prompt notice to Seller, of (i) the
occurrence, or non-occurrence, of any event the occurrence, or non-occurrence,
of which would be likely to cause any representation or warranty contained in
this Agreement to be untrue or inaccurate and (ii) any failure of Seller or
the Company, as the case may be, to comply with or satisfy any covenant,
condition or agreement to be complied with or satisfied by it hereunder;
provided, however, that the delivery of any notice pursuant to this Section
6.6 shall not limit or otherwise affect the remedies available hereunder to
the party receiving such notice.
 
  Section 6.7 Public Announcements. The Company and Seller shall consult with
each other before issuing any press release or otherwise making any public
statements with respect to the Merger and shall not issue any such press
release or make any such public statement prior to such consultation, except
as may be required by Law or any listing agreement with the National
Association of Securities Dealers, Inc.
 
  Section 6.8 Customer Retention. To the extent permitted by law or applicable
regulation, Seller shall use all reasonable efforts to assist the Company in
its efforts to retain Seller's customers for the surviving corporation. Such
efforts shall include making introductions of the Company's employees to such
customers, assisting in the mailing of information prepared by the Company and
reasonably acceptable to Seller, to such customers and actively participating
in any "transitional marketing programs" as the Company shall reasonably
request.
 
  Section 6.9 Data Services Conversion. The Company, at the Company's expense
(including Seller's costs of terminating any of Seller's data processing
contracts, labor costs, equipment purchases and any related write-offs) shall
use all reasonable efforts to complete the Data Processing Conversion as soon
as practicable
 
                                     A-30
<PAGE>
 
after the date of this Agreement. The Seller and the Company agree to
negotiate in good faith to enter into a data processing services contract with
terms and conditions and costs to the Seller, no less favorable to Seller than
Seller's current data processing services contracts. The Company shall be
responsible to provide to Seller the appropriate consultants and employees
necessary to complete the Data Processing Conversion.
 
  Section 6.10 Incentive Bonus Pool. Promptly following the execution and
delivery of this Agreement, Seller will establish a bonus pool equal to
$2,400,000 for employees of Seller (the "Bonus Pool"). The Bonus Pool will be
used to:
 
    (1) incent Seller's employees to retain Seller's customers;
 
    (2) incent Seller's employees to attain net income targets; and
 
    (3) retain key Seller employees during the period prior to the Effective
  Time.
 
The Bonus Pool will be administered by a committee of three persons: Dennis J.
Kuester, President of the Company, Douglas S. Gordon, Executive Vice President
of Seller, and Robert A. Schaefer, President of the Seller, or other Seller
employees reasonably acceptable to the Company. The committee will designate
participants, set targets and do all other things necessary to administer the
Bonus Pool. The committee shall act by the decision of the majority of its
members.
 
  Section 6.11. Seller Share Purchases. To the extent permitted by law, (a)
before the close of business on the last day of the Valuation Period, Seller
shall purchase and retain as treasury shares that number of shares of Seller
Common Stock equal to the number of shares of Seller Common Stock, if any,
issued pursuant to Seller stock options exercised or otherwise settled between
the date hereof and the last day of the Valuation Period, and (b) before the
Effective Time, Seller shall purchase and retain as treasury shares that
number of shares of Seller Common Stock equal to the number of shares of
Seller Common Stock, if any, issued pursuant to Seller stock options exercised
or otherwise settled after the last day of the Valuation Period and on or
before the Effective Time. Seller shall not be in breach of its obligations
with respect to this Section 6.11 if it purchases a de minimus amount of
Seller Common Stock in excess of the amount required to be purchased.
 
                       ARTICLE VII--CONDITIONS OF MERGER
 
  Section 7.1 Conditions to Obligation of Each Party to Effect the Merger. The
respective obligations of each party to effect the Merger shall be subject to
the satisfaction at or prior to the Effective Time of the following
conditions:
 
    (a) Effectiveness of the Registration Statement. The Registration
  Statement shall have been declared effective by the SEC under the
  Securities Act. No stop order suspending the effectiveness of the
  Registration Statement shall have been issued by the SEC and no proceedings
  for that purpose shall, on or prior to the Effective Time, have been
  initiated or, to the knowledge of the Company or Seller, threatened by the
  SEC.
 
    (b) Shareholder Approval. This Agreement and the Merger shall have been
  approved and adopted by the requisite vote of the shareholders of Seller.
 
    (c) Federal Reserve Board.  The Merger shall have been approved by the
  Federal Reserve Board, which approval shall not contain any materially
  burdensome condition that would significantly adversely affect the Company,
  all conditions required to be satisfied prior to the Effective Time imposed
  by the terms of such approval shall have been satisfied and all waiting
  periods relating to such approval shall have expired.
 
    (d) DFI. The Merger and the Bank Merger shall have been approved by DFI,
  which approval shall not contain any materially burdensome condition that
  would significantly adversely affect the Company, all conditions required
  to be satisfied prior to the Effective Time imposed by the terms of such
  approvals shall have been satisfied and all waiting periods relating to
  such approval shall have expired.
 
    (e) No Order. No federal or state governmental or regulatory authority or
  other agency or commission, or federal or state court of competent
  jurisdiction, shall have enacted, issued, promulgated,
 
                                     A-31
<PAGE>
 
  enforced or entered any statute, rule, regulation, executive order, decree,
  injunction or other order (whether temporary, preliminary or permanent)
  which is in effect restricting, preventing or prohibiting consummation of
  the transactions contemplated by this Agreement.
 
  Section 7.2 Additional Conditions to Obligations of the Company. The
obligations of the Company to effect the Merger are also subject to the
following conditions:
 
    (a) Representations and Warranties. Each of the representations and
  warranties of Seller contained in this Agreement, without giving effect to
  any update to the Seller Disclosure Schedule or notice to the Company under
  Section 4.5 or 6.7, shall be true and correct in all respects as of the
  date of this Agreement and (except to the extent such representations and
  warranties speak as of an earlier date) as of the Effective Time as though
  made on and as of the Effective Time; provided, however, that for purposes
  of determining the satisfaction of the condition contained in this clause,
  no effect shall be given to any exception in such representations and
  warranties relating to materiality or a Material Adverse Effect, and
  provided, further, however, that, for purposes of this clause, such
  representations and warranties shall be deemed to be true and correct in
  all material respects unless the failure or failures of such
  representations and warranties to be so true and correct, individually or
  in the aggregate, represent a Material Adverse Effect on the Seller.
  Company shall have received a certificate signed on behalf of the Seller by
  the Chief Executive Officer and the Chief Financial Officer of the Seller
  to the foregoing effect.
 
    (b) Agreements and Covenants. The Seller shall have performed or complied
  in all material respects with all agreements and covenants required by this
  Agreement to be performed or complied with by it on or prior to the
  Effective Time.
 
    (c) Consents Obtained. All Seller Approvals and all filings required to
  be made by Seller for the authorization, execution and delivery of this
  Agreement and the consummation by it of the transactions contemplated
  hereby shall have been obtained and made by Seller, except those for which
  failure to obtain such Seller Approvals or make such filings would not
  individually or in the aggregate, have a Material Adverse Effect on Seller
  and Seller Subsidiaries, taken as a whole.
 
    (d) No Challenge. There shall not be pending any action, proceeding or
  investigation before any court or administrative agency or by a government
  agency (i) challenging or seeking material damages in connection with, the
  Merger or the conversion of Seller Common Stock into Company Common Stock
  pursuant to the Merger or (ii) seeking to restrain, prohibit or limit the
  exercise of full rights of ownership or operation by the Company or the
  Company Subsidiaries of all or any portion of the business or assets of
  Seller, which in either case is reasonably likely to have a Material
  Adverse Effect on either Seller and the Seller Subsidiaries, taken as a
  whole, or the Company and the Company Subsidiaries, taken as a whole.
 
    (e) Tax Opinion. An opinion of Godfrey & Kahn, S.C., independent counsel
  to the Company, dated as of the Effective Time, substantially to the effect
  that on the basis of facts, representations and assumptions set forth in
  such opinion which are consistent with the state of facts existing at the
  Effective Time, the Merger and the Bank Merger will be treated for federal
  income tax purposes as reorganizations within the meaning of Section 368(a)
  of the Code, and accordingly that no gain or loss will be recognized by
  Seller or the Bank as a result of the Merger and the Bank Merger,
  respectively. In rendering such opinion, Godfrey & Kahn may require and
  rely upon representations and covenants contained in certificates of
  officers of the Company, the Bank, Seller, the Seller's Bank, and others.
 
    (f) Comfort Letters. The Company shall have received from KPMG Peat
  Marwick, LLP the "comfort" letters referred to in Section 4.3.
 
    (g) No Material Adverse Changes. Since the date of the Agreement, there
  has not been any change in the financial condition, results of operations
  or business of the Seller and the Seller Subsidiaries, taken as a whole,
  that either individually or in the aggregate would have a Material Adverse
  Effect on the Seller and the Seller Subsidiaries taken as a whole. The
  Company shall have received a certificate of the President and the Chief
  Financial Officer of the Seller to that effect.
 
 
                                     A-32
<PAGE>
 
  Section 7.3 Additional Conditions to Obligations of Seller. The obligation
of Seller to effect the Merger is also subject to the following conditions:
 
    (a) Representations and Warranties. Each of the representations and
  warranties of the Company set forth in this Agreement, without giving
  effect to any notice to Seller under Section 5.4 or 6.6, shall be true and
  correct in all respects as of the date of this Agreement and (except to the
  extent such representations and warranties speak as of an earlier date) as
  of the Effective Time, as though made on and as of the Effective Time;
  provided, however, that for purposes of determining the satisfaction of the
  condition contained in this clause, no effect shall be given to any
  exception in such representations and warranties relating to materiality or
  a Material Adverse Effect, and provided, further, however, that, for
  purposes of this clause, such representations and warranties shall be
  deemed to be true and correct in all material respects unless the failure
  or failures of such representations and warranties to be so true and
  correct, individually or in the aggregate, represent a Material Adverse
  Effect on the Company. The Seller shall have received a certificate signed
  on behalf of the Company by the Chief Executive Officer and the Chief
  Financial Officer of the Company to the foregoing effect.
 
    (b) Agreements and Covenants. The Company shall have performed or
  complied in all material respects with all agreements and covenants
  required by this Agreement to be performed or complied with by it on or
  prior to the Effective Time.
 
    (c) Consents Under Agreements. All consents, waivers, approvals,
  authorizations or orders required to be obtained, and all filings required
  to be made by the Company for the authorizations, execution and delivery of
  this Agreement and the consummation by it of the transactions contemplated
  hereby shall have been obtained and made by the Company, except where
  failure to obtain any consents, waivers, approvals, authorizations or
  orders required to be obtained or any filings required to be made would not
  have a Material Adverse Effect on the Company and the Company Subsidiaries,
  taken as a whole.
 
    (d) Federal Tax Opinion. The Seller shall have received an opinion of
  Skadden, Arps, Slate, Meagher & Flom LLP, in form and substance reasonably
  satisfactory to the Seller, dated as of the Effective Time, substantially
  to the effect that on the basis of facts, representations and assumptions
  set forth in such opinion which are consistent with the state of facts
  existing at the Effective Time, the Merger will be treated as a
  reorganization within the meaning of Section 368(a) of the Code, and that,
  accordingly, for federal income tax purposes:
 
      (i) No gain or loss will be recognized by the Seller as a result of
    the Merger;
 
      (ii) No gain or loss will be recognized by the shareholders of the
    Seller who exchange all of their Seller Common Stock solely for Company
    Common Stock pursuant to the Merger (except with respect to cash
    received in lieu of a fractional share interest in Company Common
    Stock); and
 
      (iii) The aggregate tax basis of the Company Common Stock received by
    shareholders who exchange all of their Seller Common Stock solely for
    Company Common Stock pursuant to the Merger will be the same as the
    aggregate tax basis of the Seller Common Stock surrendered in exchange
    therefor (reduced by any amount allocable to a fractional share
    interest for which cash is received).
 
    In rendering such opinion, the Seller's Counsel may require and rely upon
  representations and covenants contained in certificates of officers of
  Company, the Bank, the Seller, the Seller's Bank and others.
 
                           ARTICLE VIII--INDUCEMENT
 
  Section 8.1 Inducement.
 
    (a) As a condition and inducement to the Company's willingness to enter
  into and perform its obligations under this Agreement, unless a Nullifying
  Event (as such term is defined below) shall have occurred and be continuing
  at the time the Agreement is terminated, in the event that (i) this
  Agreement is terminated pursuant to Article IX hereof (regardless of
  whether such termination is by Company or Seller),
 
                                     A-33
<PAGE>
 
    (ii) prior to or concurrently with such termination a Trigger Event (as
  such term is defined below) shall have occurred, and (iii) prior to,
  concurrently with or within 18 months after such termination an Acquisition
  Event (as such term is defined below) shall have occurred, Seller shall pay
  to Company a cash fee of $30 million. Such fee shall be payable in
  immediately available funds on or before the second business day following
  the Acquisition Event. In addition, in the event that (i) this Agreement is
  terminated pursuant to Article IX hereof (regardless of whether such
  termination is by the Company or Seller) and (ii) a Trigger Event has
  occurred, Seller shall pay to the Company its reasonable out-of-pocket
  expenses related to this transaction in an aggregate amount not to exceed
  $2,500,000 in immediately available funds on or before the second business
  day following such termination of this Agreement.
 
    (b) As used herein, a "Trigger Event" shall mean the occurrence of any of
  the following events:
 
      (i) Seller's Board of Directors shall have failed to approve or
    recommend this Agreement or the Merger or shall have withdrawn or
    modified in a manner adverse to the Company its approval or
    recommendation of this Agreement or the Merger, or shall refuse to
    reaffirm its approval or recommendation upon the Company's reasonable
    request, or shall have resolved or publicly announced an intention to
    do any of the foregoing;
 
      (ii) Seller or any Significant Subsidiary (as such term is defined
    below), or the Board of Directors of Seller or a Significant
    Subsidiary, shall have recommended to the stockholders of Seller any
    Acquisition Proposal (as such term is defined below) or shall have
    entered into an agreement with respect to, or authorized, approved,
    proposed or publicly announced its intention to enter into, any
    Acquisition Proposal;
 
      (iii) this Agreement or the Merger shall not have been approved at a
    meeting of Seller stockholders which has been held for that purpose
    prior to termination of this Agreement in accordance with its terms, if
    prior thereto it shall have been publicly announced that any person
    (other than the Company or any Company Subsidiary) shall have made, or
    disclosed an intention to make, an Acquisition Proposal;
 
      (iv) any person (together with its affiliates and associates) or
    group (as such terms are used for purposes of Section 13(d) of the
    Exchange Act) (other than the Company and the Company Subsidiaries)
    shall have acquired beneficial ownership (as such term is used for
    purposes of Section 13(d) of the Exchange Act) or the right to acquire
    beneficial ownership of 20% or more of the then outstanding shares of
    the stock then entitled to vote generally in the election of directors
    of Seller or any Significant Subsidiary; or
 
      (v) following the making of an Acquisition Proposal, Seller shall
    have willfully breached any covenant or agreement contained in this
    Agreement such that Company would be entitled to terminate this
    Agreement under Section 9.1(a)(ii) (without regard to any grace period
    provided for therein) unless such breach is promptly cured without
    jeopardizing consummation of the Merger pursuant to the terms of this
    Agreement.
 
    (c) As used herein, "Acquisition Event" shall mean the consummation of
  any event described in clauses (A), (B) or (C) in the definition of
  "Acquisition Proposal," except that the percentage reference contained in
  clause (C) of such definition shall be 50% instead of 20%.
 
    (d) As used herein, "Acquisition Proposal" shall mean any (i) publicly
  announced proposal, (ii) regulatory application or notice (whether in draft
  or final form), (iii) agreement or understanding, (iv) disclosure of an
  intention to make a proposal, or (v) amendment to any of the foregoing,
  made or filed on or after the date hereof, in each case with respect to any
  of the following transactions with a counterparty other than the Company or
  any Company Subsidiary: (A) a merger or consolidation, or any similar
  transaction, involving Seller or any Significant Subsidiary (other than
  mergers, consolidations, or any similar transactions involving solely
  Seller and/or one or more wholly owned Subsidiaries of Seller and other
  than a merger or consolidation as to which the common shareholders of
  Seller immediately prior thereto in the aggregate own at least 70% of the
  common stock of the publicly held surviving or successor corporation (or
  any publicly held ultimate parent company thereof) immediately following
  consummation
 
                                     A-34
<PAGE>
 
  thereof); (B) a purchase, lease or other acquisition of all or
  substantially all of the assets or deposits of Seller or any Significant
  Subsidiary; or (C) a purchase or other acquisition (including by way of
  merger, consolidation, share exchange or otherwise) of securities
  representing 20% or more of the voting power of Seller or any Significant
  Subsidiary.
 
    (e) As used herein, "Nullifying Event" shall mean any of the following
  events occurring and continuing at a time when Seller is not in material
  breach of any of its covenants or agreements contained in the Agreement;
  (i) the Company shall be in breach of any of its covenants or agreements
  contained in the Agreement such that Seller shall be entitled to terminate
  the Agreement pursuant to Section 9.1(iii) (without regard to any grace
  period provided for therein), or (ii) the Board of Directors of the Company
  shall have failed to approve or recommend the Merger or the transactions
  contemplated hereby or shall have withdrawn, modified or changed in any
  manner adverse to Seller its approval or recommendation of the Merger or
  the transactions contemplated hereby or shall have resolved or publicly
  announced its intention to do any of the foregoing.
 
    (f) As used herein, "Significant Subsidiary" shall mean a "significant
  subsidiary," of Seller as defined in Rule 1-02 of Regulation S-X
  promulgated by the Securities and Exchange Commission.
 
                 ARTICLE IX--TERMINATION, AMENDMENT AND WAIVER
 
  Section 9.1 Termination.
 
    (a) This Agreement may be terminated at any time prior to the Effective
  Time, whether before or after approval of the matters presented in
  connection with the Merger by the shareholders of Seller:
 
      (i) by mutual consent of the Company and Seller by a vote of a
    majority of the members of the entire Board of Directors;
 
      (ii) by either Company or Seller if any approval of the stockholders
    of the Seller required for the consummation of the Merger shall not
    have been obtained by reason of the failure to obtain the required vote
    at a duly held meeting of such stockholders or at any adjournment or
    postponement thereof;
 
      (iii) by Seller or the Company (A) if there has been a breach in any
    material respect (except that where any statement in a representation
    or warranty expressly includes a standard of materiality, such
    statement shall have been breached in any respect) of any
    representation, warranty, covenant or agreement on the part of Seller,
    on the one hand, or the Company, on the other hand, set forth in this
    Agreement, or (B) if any representation or warranty of Seller, on the
    one hand, or the Company, on the other hand, shall be discovered to
    have become untrue in any material respect (except that where any
    statement in a representation or warranty expressly includes a standard
    of materiality, such statement shall have become untrue in any
    respect), in either case which breach or other condition has not been
    cured within 30 business days following receipt by the nonterminating
    party of notice of such breach or other condition, or which breach by
    its nature, cannot be cured prior to Closing; provided, however,
    neither party shall have the right to terminate this Agreement pursuant
    to this Section 9.1(a)(iii) unless the breach of any representation or
    warranty (but not breaches of covenants or agreements), together with
    all other such breaches, would entitle the party receiving such
    representation or warranty not to consummate the transactions
    contemplated hereby under Section 7.2(a) (in the case of a breach of a
    representation or warranty by the Seller) or Section 7.3(a) (in the
    case of a breach of a representation or warranty by Company); and,
    provided further this Agreement may not be terminated pursuant to this
    clause (iii) by the breaching party or party making any representation
    or warranty which shall have become untrue in any material respect;
 
      (iv) by either the Company or Seller if any permanent injunction
    preventing the consummation of the Merger shall have become final and
    nonappealable;
 
      (v) by either the Company or Seller if the Merger shall not have been
    consummated by December 31, 1997, for a reason other than the failure
    of the party seeking termination to comply with its
 
                                     A-35
<PAGE>
 
    obligations under this Agreement; provided that if the Merger shall not
    have been consummated by December 31, 1997 as a result of proceedings
    of a governmental authority or litigation then the date on which either
    the Company or the Seller may terminate this Agreement under this
    Section 9.1(a)(v) shall be extended to the earlier of (A) the elapse of
    a reasonable period of time necessary to consummate the Merger
    following the final termination of proceedings of a governmental
    authority or (B) April 30, 1998;
 
      (vi) by either the Company or Seller if the Federal Reserve Board has
    denied approval of the Merger, and neither the Company nor Seller has,
    within 30 days after the entry of such order denying approval, filed a
    petition seeking review of such order as provided by applicable law; or
 
      (vii) by the Seller, if both of the conditions in (A) and (B) below
    exist on the day preceding the anticipated Effective Time and the
    Company has not elected to cure such conditions as set forth in (D)
    below:
 
        (A) the average of the daily closing price of a share of Company
      Common Stock as reported on the consolidated tape of the NASDAQ/NMS
      during the period of 10 trading days ending at the close of the
      third trading day immediately preceding the Effective Time (the
      "Company Average Price") is less than 80% of the average of the
      final bid and asked price on 10 trading days ending on the day
      immediately prior to signing; and
 
        (B) the number obtained by dividing the Company Average Price by
      the average closing price of Company Common Stock as reported on the
      consolidated tape of the NASDAQ/NMS for the 10 trading days
      immediately preceding the public announcement of this Agreement is
      less than the number obtained by dividing the Final Index Price (as
      defined below) by the Initial Index Price (as defined below) and
      subtracting .15 from such quotient.
 
        (C) For purposes of this Section 9.1(vii):
 
                (1) The "Index Group" shall mean all of those companies listed
              on Exhibit 9.1 the common stock of which is publicly traded and
              as to which there is no pending publicly announced proposal at
              any time during the period of 10 trading days ending at the end
              of the third trading day immediately preceding the Effective
              Time for such company to be acquired or to acquire another
              company or with respect to any other extraordinary transaction
              or event (other than any transaction contemplated in Section
              9.1(vii)(C)(4));
 
                (2) The "Initial Index Price" shall mean the average of the
              per share closing prices of the common stock of the companies
              comprising the Index Group (weighted in accordance with the
              weighting factor set forth on Exhibit 9.1), as reported on the
              consolidated transactions reporting system for the market or
              exchange on which such common stock is principally traded, for
              the 10 trading days immediately preceding the public
              announcement of this Agreement;
 
                (3) The "Final Price" of any company belonging to the Index
              Group shall mean the average of the daily closing sale prices of
              a share of common stock of such company, as reported in the
              consolidated transaction reporting system for the market or
              exchange on which such common stock is principally traded,
              during the period of 10 trading days ending at the end of third
              trading day immediately preceding the Effective Time;
 
                (4) The "Final Index Price" shall mean the average of the
              Final Prices for all of the companies comprising the Index
              Group. If the Company or any company belonging to the Index
              Group declares a stock dividend or effects a reclassification,
              recapitalization, split-up, combination, exchange of shares or
              similar transaction between the date of this Agreement and the
              Effective Time, the closing prices for the common stock of such
              company shall be appropriately adjusted for the purposes of the
              definitions above so as to be comparable to the closing price on
              the date of this Agreement;
 
        (D) The Company shall have the right, but not the obligation, to
      increase the Stock Amount in a manner such that the conditions set
      forth in either (A) or (B), above, shall be deemed not to
 
                                     A-36
<PAGE>
 
      exist. For purposes hereof, the condition set forth in (A) above
      shall be deemed not to exist if the Stock Amount is increased so
      that the Stock Amount (as increased) multiplied by the Valuation
      Period Market Value is not less than $375,971,980 (i.e. $31.20
      multiplied by the initial Stock Amount). For purpose hereof, the
      condition set forth in (B), above, shall be deemed not to exist if
      the Stock Amount is increased in an amount such that if the Company
      Average Price (for purposes of (B), above) were equal to the Company
      Average Price (as previously calculated) plus the Adjustment Amount
      (as defined below), the condition set forth in (B) above would not
      exist. The Adjustment Amount shall equal (x) the product of the
      Company Average Price (as previously calculated) and the number of
      shares by which the Stock Amount is increased, divided by (y) the
      Stock Amount (prior to such increase).
 
  Section 9.2 Effect of Termination. In the event of the termination of this
Agreement pursuant to Section 9.1, this Agreement shall forthwith become void
and all rights and obligations of any party hereto shall cease except: (i) as
set forth in Section 10.1 of this Agreement and (ii) nothing herein shall
relieve any party from liability for any willful breach of this Agreement or
shall restrict either party's rights in the case thereof.
 
  Section 9.3 Amendment. This Agreement may be amended by the parties hereto
by action taken by or on behalf of their respective Boards of Directors at any
time prior to the Effective Time; provided, however, that, after approval of
the Merger by the shareholders of Seller, no amendment may be made, without
further approval of such shareholders which would reduce the amount or change
the type of consideration into which each share of Seller Common Stock shall
be converted pursuant to this Agreement upon consummation of the Merger. This
Agreement may not be amended except by an instrument in writing signed by the
parties hereto.
 
  Section 9.4 Waiver. At any time prior to the Effective Time, the parties
hereto may (a) extend the time for the performance of any of the obligations
or other acts of the other party hereto, (b) waive any inaccuracies in the
representations and warranties contained herein or in any document delivered
pursuant hereto and (c) waive compliance with any of the agreements or
conditions contained herein. Any such extension or waiver shall be valid only
if set forth in a written instrument signed on behalf of such party, but such
extension or waiver or failure to insist on strict compliance with an
obligation, covenant, agreement or condition shall not operate as a waiver of,
or estoppel with respect to, any subsequent or other failure.
 
                         ARTICLE X--GENERAL PROVISIONS
 
  Section 10.1 Non-Survival of Representations, Warranties and Agreements. The
representations, warranties and agreements in this Agreement shall terminate
at the Effective Time or upon the termination of this Agreement pursuant to
Article VIII, except that the agreements set forth in Article I and Sections
6.4 and 6.5 shall survive the Effective Time and those set forth in Sections
4.4(b), 4.7, 5.3(b), 8.1 and Article X hereof shall survive termination
indefinitely.
 
  Section 10.2 Enforcement of Agreement. The parties hereto agree that
irreparable damage would occur in the event that the provisions contained in
the last sentence of each of Sections 4.4(b) and 5.3(b) and Section 6.5 of
this Agreement were not performed in accordance with its 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 the last
sentence of Section 4.4(b), and of Section 5.3(b) and Section 6.5 of this
Agreement and to enforce specifically the terms and provisions thereof 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 in equity.
 
  Section 10.3 Notices. All notices and other communications given or made
pursuant hereto shall be in writing and shall be deemed given if delivered
personally, telecopied (with confirmation), mailed by registered
 
                                     A-37
<PAGE>
 
or certified mail (postage prepaid, 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) and shall be effective upon receipt:
 
    (a) If to the Company:
 
      Marshall & Ilsley Corporation
      770 North Water Street
      Milwaukee, Wisconsin 53202
      Telecopier: (414) 764-7788
      Attention: Gordon H. Gunnlaugsson
 
    With a copy to:
 
      Godfrey & Kahn, S.C.
      780 North Water Street
      Milwaukee, Wisconsin 53202
      Telecopier: (414) 273-5198
      Attention: Kenneth C. Hunt
 
    (b) If to Seller:
 
      Security Capital Corporation
      184 West Wisconsin Avenue
      Milwaukee, Wisconsin 53201
      Telecopier: (414) 277-6406
      Attention: Roger D. Kamin
 
    With a copy to:
 
      Skadden, Arps, Slate, Meagher & Flom LLP
      919 Third Avenue
      New York, New York 10022
      Telecopier: (212) 735-2000
      Attention: Fred B. White III, Esq.
 
  Section 10.4 Certain Definitions. For purposes of this Agreement, the term:
 
    (a) "affiliate" means a person that directly or indirectly, through one
  or more intermediaries, controls, is controlled by, or is under common
  control with, the first mentioned person; including, without limitation,
  any partnership or joint venture in which any person (either alone, or
  through or together with any other subsidiary) has, directly or indirectly,
  an interest of 5% or more;
 
    (b) "beneficial owner," with respect to any Shares, means a person who
  shall be deemed to be the beneficial owner of such Shares (i) which such
  person or any of its affiliates or associates beneficially owns, directly
  or indirectly, (ii) which such person or any of its affiliates or
  associates (as such term is defined in Rule 12b-2 of the Exchange Act) has,
  directly or indirectly, (A) the right to acquire (whether such right is
  exercisable immediately or subject only to the passage of time), pursuant
  to any agreement, arrangement or understanding or upon the exercise of
  consideration rights, exchange rights, warrants or options, or otherwise,
  or (B) the right to vote pursuant to any agreement, arrangement or
  understanding, (iii) which are beneficially owned, directly or indirectly,
  by any other persons with whom such person or any of its affiliates or
  associates has any agreement, arrangement or understanding for the purpose
  of acquiring, holding, voting or disposing of any Shares or (iv) pursuant
  to Section 13(d) of the Exchange Act and any rules or regulations
  promulgated thereunder;
 
    (c) "business day" means any day other than a day on which banks in
  Wisconsin are required or authorized to be closed;
 
    (d) "control" (including the terms "controlled by" and "under common
  control with") means the possession, directly or indirectly or as trustee
  or executor, of the power to direct or cause the direction of the
  management or policies of a person, whether through the ownership of stock
  or as trustee or executor, by contract or credit arrangement or otherwise;
 
                                     A-38
<PAGE>
 
    (e) "person" means an individual, corporation, partnership, association,
  trust, unincorporated organization, other entity or group (as defined in
  Section 13(d) of the Exchange Act); and
 
    (f) "subsidiary" or "subsidiaries" of Seller, the Company, the Surviving
  Corporation, or any other person, means any corporation, partnership, joint
  venture or other legal entity of which Seller, the Company, the Surviving
  Corporation or such other person, as the case may be (either alone or
  through or together with any other subsidiary), owns, directly or
  indirectly, 50% or more of the stock or other equity interests the holders
  of which are generally entitled to vote for the election of the board of
  directors or other governing body of such corporation or other legal
  entity.
 
  Section 10.5 Headings. The headings contained in this Agreement are for
reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.
 
  Section 10.6 Severability. If any term or other provision of this Agreement
is invalid, illegal or incapable of being enforced by any rule of law or
public policy, all other conditions and provisions of this Agreement shall
nevertheless remain in full force and effect so long as the economic or legal
substance of the transactions contemplated hereby is not affected in any
manner adverse to any party. Upon such determination that any term or other
provision is invalid, illegal or incapable of being enforced, the parties
hereto shall negotiate in good faith to modify this Agreement so as to effect
the original intent of the parties as closely as possible in an acceptable
manner to the end that transactions contemplated hereby are fulfilled to the
extent possible.
 
  Section 10.7 Entire Agreement. This Agreement constitutes the entire
agreement of the parties and supersedes all prior agreements and undertakings,
other than the confidentiality agreement, both written and oral, between the
parties, or any of them, with respect to the subject matter hereof and, except
as otherwise expressly provided herein, are not intended to confer upon any
other person any rights or remedies hereunder.
 
  Section 10.8 Assignment. This Agreement shall not be assigned by operation
of law or otherwise, except that the Company may assign all or any of its
rights hereunder and thereunder to any affiliate provided that no such
assignment shall relieve the assigning party of its obligations hereunder.
 
  Section 10.9 Parties in Interest. This Agreement (including Annex B hereto)
shall be binding upon and inure solely to the benefit of each party hereto,
and nothing in this Agreement, express or implied, is intended to or shall
confer upon any other person any right, benefit or remedy of any nature
whatsoever under or by reason of this Agreement, other than (i) Section 6.5
(which is intended to be for the benefit of the Indemnified Parties and may be
enforced by such Indemnified Parties) and (ii) Section 5.7, Section 6.4 and
Annex B (which are intended to be for the benefit of the directors, officers
and employees of the Seller and the Seller Subsidiaries and may be enforced by
such persons).
 
  Section 10.10 Governing Law. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of Wisconsin, regardless
of the laws that might otherwise govern under applicable principles of
conflicts of law.
 
  Section 10.11 Counterparts. This Agreement may be executed in one or more
counterparts, and by the different parties hereto in separate counterparts,
each of which when executed shall be deemed to be an original but all of which
taken together shall constitute one and the same agreement.
 
  In Witness Whereof, the Company and Seller have caused this Agreement to be
executed as of the date first written above by their respective officers
thereunto duly authorized.
 
                                          Security Capital Corporation
 
                                               /s/ William G. Schuett, Sr.
                                          By: _________________________________
                                                  William G. Schuett, Sr.
                                               President and Chief Executive
                                                          Officer
                                          Marshall & Ilsley Corporation
 
                                                   /s/ James B. Wigdale
                                          By: _________________________________
                                                      James B. Wigdale
                                              Chairman of the Board and Chief
                                                     Executive Officer
 
                                     A-39
<PAGE>
 
                                                                        ANNEX B
 
                           EMPLOYEE BENEFIT MATTERS
 
  1. Conduct of Business Between Date of Signing the Agreement and the
Effective Time. Between the date of signing of the Agreement and the Effective
Time (i) there will be no increases in base salary for the employees of Seller
or Seller Subsidiaries who have Employment Agreements; (ii) other employees
may receive increases in base salary and bonuses in the ordinary course of
business consistent with past practice, subject to Paragraph 14 hereof; (iii)
no new programs or agreements providing compensation for employees or
directors will be adopted, existing programs or agreements will not be amended
or modified except as provided herein or in Agreements executed by employees
and/or directors in connection herewith, and no further grants or awards will
be made under existing programs or agreements except as explicitly provided
herein; (iv) no new employment agreements will be granted and the existing
Employment Agreements will not be amended except as provided herein or in the
Agreements executed by employees contemporaneously herewith; (v) no new
elections may be made to defer compensation for fiscal 1998; (vi) Seller
contributions to its 401(k) plan will not be in excess of a percentage level
consistent with prior Seller contributions; and (vii) Seller or Seller
Subsidiaries will only pay severance to those employees who are terminated by
their employer and then only in amounts and for a period consistent with past
practice of the employer.
 
  2. General.
 
    (a) Those individuals who are employed by the Seller and the Seller
  Subsidiaries as of the Effective Time and who remain, at the Company's
  discretion, employees of the Company or its subsidiaries following the
  Effective Time shall be referred to hereinafter as "Affected Employees".
 
    (b) The Company will give Affected Employees full credit for their prior
  service with the Seller or the Seller Subsidiaries or any subsidiary of the
  Seller or the Seller Subsidiaries (i) for purposes of eligibility and
  vesting under any qualified or nonqualified retirement or profit sharing
  plans or vacation plans or arrangements maintained by the Company and (ii)
  for purposes of eligibility under any welfare benefit plans maintained by
  the Company. Notwithstanding anything contained in this Annex or the Merger
  Agreement to the contrary, for purposes of the Company's retiree health
  plan, Affected Employees will be given access to the retiree health plan if
  they meet the eligibility criteria for the plan, but the cost of health
  insurance under the plan will be borne 100% by the Affected Employees with
  no subsidy by the Company.
 
    (c) The Company will, or will cause the Seller or the Seller Subsidiaries
  to, waive all limitations as to preexisting conditions and waiting periods
  with respect to participation and coverage requirements applicable to the
  Affected Employees under any welfare benefit plans that such employees may
  be eligible to participate in after the Effective Time, other than
  limitations or waiting periods that are already in effect with respect to
  such employees and that have not been satisfied as of the Effective Time
  under any welfare plan maintained for the Affected Employees immediately
  prior to the Effective Time.
 
  3. Pension Plan and 401(k) Plan. Seller's qualified pension plan will be
frozen on December 31, 1997 with full vesting as of the Effective Time and may
be terminated at the discretion of the Company. Accounts in the 401(k) plan of
participants who are employed at the Effective Time by the Seller or Seller
Subsidiaries will be fully vested as of the Effective Time. The Company
reserves the right thereafter to merge or terminate the 401(k) plan.
 
  4. Merger as Change in Control. The Merger will constitute a change in
control for the purposes of all qualified and non-qualified plans and
employment agreements of Seller and Seller Subsidiaries, including, but not
limited to, the Seller's Change in Control Severance Plan hereinafter
described.
 
  5. Employment Agreements. The Employment Agreements for six executives of
the Seller are being contemporaneously amended by execution of Agreements
between the Executive, Seller, Seller's bank subsidiary and the Company in the
form attached to the Merger Agreement. An Employment Agreement with one (1)
officer containing the provisions described above will be reinstated with a
term ending on December 31, 1997.
 
                                     A-40
<PAGE>
 
  6. Employee Benefits. Except as provided in Paragraphs 7, 12 and 17 hereof,
Affected Employees will be integrated into the welfare and employee benefit
plans of the Company, including health, dental, group term life insurance,
tuition reimbursement, long-term disability and qualified employee benefit
plans, as of January 1, 1998. Seller's welfare benefit plans shall continue in
force until December 31, 1997. Company reserves the right, at any time and
from time to time, to modify or amend, in whole or in part, any or all
provisions of such plans, except to the extent otherwise provided in this
Annex.
 
  7. Severance Plan. The Seller's Change in Control Severance Plan (a) will
govern terminations of employment which occur within two years following the
Effective Time (as modified in this Paragraph 7), except for (i) employees who
have in effect an Employment Agreement discussed in Section 5 of this Annex B
and (ii) other employees of Seller or Seller Subsidiaries who have employment
agreements unless they waive all rights to compensation, profit percentages,
rights of first refusal and severance under those employment agreements and
(b) will contain provisions consistent with this Paragraph 7. In the case of
an employee of Seller or any Seller Subsidiary whose employment is terminated
between the eighteen-month and second anniversaries of the Effective Time,
such employee's entitlement to severance for a period under the grid
previously provided to the Company by the Seller and attached hereto will be
reduced by two months for every one month which elapses from the eighteen-
month anniversary of the Effective Time to the date of termination until the
severance period is reduced to that contained in the Company's severance plan
for comparable classes of employees. For example, if an employee would be
entitled to 24 months under the grid, if the employee were terminated in the
nineteenth month after the Effective Time, he would be entitled to 22 months
of severance. In all events, the amount, including the cost of benefits, to
which each terminated employee is entitled under Seller's severance plan will
not exceed the amount contained in the Change in Control Severance Benefits
schedule provided to Company by Seller dated March 7, 1997. Seller will
provide a copy of such schedule to the Company which contains the name of each
employee. The Seller's Change in Control Severance Plan will also be
consistent with the following: (i) severance is only payable if the Company
terminates the employee from his current position and does not offer him a
position with comparable pay and benefits at a location no greater than 25
miles from the location where he is currently employed; (ii) the amount of
severance is determined according to the attached grid prepared by Seller ONLY
IF the employee signs a complete and permanent release of all claims arising
out of his employment, including age discrimination, and does not revoke the
release within the statutory period for revocation; (iii) health and dental
continuation for the severance term will be under COBRA, but for no shorter
period than for the severance term; (iv) long-term disability eligibility ends
on date of termination of employment; (v) if the employee obtains other
employment, each severance payment is reduced by 50%, except that if the new
job is with the Company or an affiliate, severance stops on the first day of
employment; and (vi) severance pay does not count for purposes of determining
benefits under any other qualified or nonqualified plans. After the expiration
of Seller's Change in Control Severance Plan, employees will be eligible to be
considered under the Company's regular severance plan. To the extent that
Seller's Change in Control Severance Plan is not consistent with the
provisions hereof, it shall be amended by Seller's Board no later than the
Effective Time.
 
  8. Rabbi Trusts. The rabbi trust which funds the Seller's SERP may be
amended to provide that upon a change in control, an obligation will be
triggered to (a) fund the trust at a level equal to at least 110% of accrued
pension benefits and (b) revalue the accrued pension benefits annually and
deposit the amount necessary to maintain funding at the 110% level. Also, the
Nonqualified Deferred Compensation Trust may be amended to provide that upon a
change in control, an obligation will be triggered to (a) fund the trust at a
level equal to at least 100% of accrued benefits and (b) revalue the accrued
benefits annually and deposit the amount necessary to maintain funding at the
100% level.
 
  9. Deferred Compensation Plan for Officers. The Deferred Compensation Plan
for Officers and any similar deferred compensation arrangements shall be
amended (with the consent of participants given as of the time of execution of
the Merger Agreement) (a) to clarify that the excess ESOP allocation formula
will apply only to regular allocations made on the basis of compensation, and
will not apply to allocations based on account
 
                                     A-41
<PAGE>
 
balances, as described in Paragraph 11(b)(iii) of this Annex B, (b) to provide
for the payment of that portion of a participant's benefits otherwise
scheduled to be made in 1997 on the earlier of the payment date otherwise
elected by the participant or the date which is one week prior to the
scheduled Effective Time, (c) to provide that no amendment (other than the
amendments described in this paragraph) may be made to the Deferred
Compensation Plan for Officers or such similar deferred compensation
arrangements which would serve to accelerate the payment of benefits or
decrease the rate of interest under such plan or arrangements, and (d) to
clarify that, regardless of when the Effective Time falls within the plan
year, proportional allocation of the Company's matching contribution under the
Deferred Compensation Plan for Officers shall occur. In addition, rules may be
adopted and implemented under the Deferred Compensation Plan for Officers or
other similar deferred compensation arrangements which authorize the
Administrative Committee to allow each participant to make a new, irrevocable
election to confirm or deny such participant's previous election to defer
amounts in respect of calendar year 1997 which have not yet been earned and
payable. In addition, the Deferred Compensation Plan for Officers shall be
amended (with the consent of participants given as of the time of execution of
the Merger Agreement) to provide that (a) participants will be given an
election, with respect to the treatment of their stock accounts, which is the
same as the election being given to shareholders of the Seller pursuant to the
Merger Agreement; (b) to the extent necessary to conform to a participant's
election, any cash credited to the participant's account will be converted
into additional shares of stock of the Company based upon the trading price of
said stock; and (c) any cash credited to the participant's account pursuant to
a cash election will be credited thereafter with an interest rate equal to
Moody's Average Corporate Bond Yield Index.
 
  10. Non-Employee Director Deferred Compensation Plan. Seller's Non-Employee
Director Deferred Compensation Plan may be amended (a) to provide for the
payment of that portion of a participant's benefit otherwise scheduled to be
made in 1997 on the earlier of the payment date otherwise elected by the
participant or the date which is one week prior to the scheduled Effective
Time, (b) to provide that no amendment (other than the amendments described in
this paragraph) may be made to the Non-Employee Director Deferred Compensation
Plan which would serve to accelerate the payment of benefits or decrease the
rate of interest under such plan and (c) to clarify that, regardless of when
the Effective Time falls within the plan year, proportional allocation of the
Company's matching contribution under the Non-Employee Director Deferred
Compensation Plan shall occur. In addition, rules may be adopted and
implemented under the Non-Employee Director Deferred Compensation Plan which
authorize the Administrative Committee to allow each participant to make a
new, irrevocable election to confirm or deny such participant's previous
election to defer amounts in respect of calendar year 1997 which have not yet
been earned and payable. In addition, the Non-Employee Director Deferred
Compensation Plan shall be amended (with the consent of participants given as
of the time of the execution of Merger Agreement) as described in the last
sentence of paragraph 9 hereof.
 
  11. ESOP. (a) As of the day (the "Contribution Date") immediately prior to
the Effective Time, the Seller shall make a contribution to the Seller's
Employee Stock Ownership Plan (the "ESOP") equal to the aggregate contribution
that would have been made pursuant to Section 5(b) of the ESOP in respect of
the then current Plan Year multiplied by a fraction (the "Fraction"), the
numerator of which is the number of days in the current Plan Year through and
including the Effective Time and the denominator of which is 365, and shall
cause the Trustee of the ESOP to use the full amount of such contribution
promptly to repay a portion of the outstanding ESOP indebtedness. As a result
of the aforementioned contribution and repayment, the Seller shall take such
action as may be necessary or appropriate to cause shares of the Seller's
stock to be released (as of the Contribution Date) from the suspense account
maintained under the ESOP and allocated (as of the Contribution Date) to the
accounts of each Participant (as defined in the ESOP) who would be entitled to
an allocation for the then current Plan Year if (i) the Contribution Date were
an Anniversary Date (as defined in the ESOP) and (ii) the 1,000 Hour of
Service requirement set forth in Section 4 of the ESOP were multiplied by the
Fraction; such allocation shall be effected in accordance with the ratio of
(1) the Covered Compensation (as defined in the ESOP) of such Participant for
the portion of the Plan Year through the end of the last payroll period
commencing prior to the Contribution Date to (2) the aggregate Covered
Compensation through the end of the last payroll period commencing prior to
the Contribution Date of all Participants entitled to such allocation.
 
                                     A-42
<PAGE>
 
  (b) The Company and Seller agree to take such action as may be necessary or
appropriate:
 
    (i) to cause the ESOP to terminate as of the Effective Time and for all
  Account balances to become fully vested and nonforfeitable as of such date;
 
    (ii) to cause the Trustee of the ESOP to sell, from the suspense account
  maintained under the ESOP, shares of stock of the Company with an aggregate
  value equal to the remaining outstanding ESOP indebtedness, after giving
  effect to the repayment described in paragraph (a) hereof, and to use the
  proceeds of such sale to repay in full all such outstanding ESOP
  indebtedness;
 
    (iii) to cause those shares of stock of the Company (and any cash)
  remaining in the suspense account maintained under the ESOP, after giving
  effect to the aforementioned sale (the "Remaining Shares"), to be allocated
  in the following manner: (A) that portion of the Remaining Shares which, if
  allocated, would be treated as an "annual addition" within the meaning of
  Section 415 of the Code (without regard to the limitations thereof) shall
  be allocated among all Participants who were actively employed by the
  Seller or Seller Subsidiaries as of January 1, 1997 in proportion to the
  number of shares allocated to such Participants' ESOP Accounts as of the
  Effective Time (or, in the case of a Participant whose employment with the
  Seller and Seller Subsidiaries terminates between January 1, 1997 through
  and including the day prior to the Effective Time, the number of shares
  allocated to such Participant's ESOP Account as of December 31, 1996). That
  portion of the Remaining Shares allocated under this clause (A) which is in
  excess of a Participant's limitation under Section 415(c) of the Code (the
  "Excess Allocations") shall be deemed to have been allocated under a plan
  not qualified under Section 401(a) of the Code, and such Excess Allocations
  shall not be subject to the provisions of Section 401(a)(31) of the Code
  described in subparagraph (iv) hereof; and (B) that portion of the
  Remaining Shares which, if allocated, would not be treated as an "annual
  addition" within the meaning of Section 415(c) of the Code shall be
  allocated among all Participants in proportion to the number of shares
  allocated to such Participants' ESOP Accounts as of the Effective Time (or,
  in the case of a Participant whose employment with the Seller and Seller
  Subsidiaries terminates between January 1, 1997 through and including the
  day prior to the Effective Time, the number of shares allocated to such
  Participant's ESOP Account as of December 31, 1996), without taking into
  account the allocations made under clause (A) above; and
 
    (iv) for the account balances of all Participants to be distributed in a
  lump sum (or transferred in accordance with Section 401(a)(31) of the Code,
  except as provided in subparagraph (iii) above) as soon as practicable
  following the later of (A) the Effective Time or (B) the date of receipt of
  a favorable determination letter from the Internal Revenue Service (the
  "Service") regarding the qualified status of the ESOP upon its termination.
 
  (c) As soon as practicable after the date hereof, the Seller shall file a
request for an advance determination letter from the Service regarding the
continued qualified status of the ESOP upon its termination, and the parties
hereby agree to cooperate fully in all matters pertaining to such filing
(including, but not limited to, making such changes to the ESOP and the
proposed allocations described herein as may be requested by the Service as a
condition to its issuance of a favorable determination letter). If, despite
the Seller's attempt to obtain such a favorable determination letter, the
Service does not permit all or any portion of the Remaining Shares to be
allocated as of the Effective Time as contemplated hereby, the parties hereby
agree to take such action as may be necessary to allocate the Remaining Shares
(or amounts attributable thereto) as rapidly as possible among participants in
the ESOP in such other manner as is consistent with meeting their respective
fiduciary duties under ERISA and with obtaining the Service's determination
that the ESOP retains its qualified status upon its termination; provided,
however, that no such action shall create any liability for the Company to
make any contributions to the ESOP or to provide any replacement benefits to
Participants outside the ESOP. In all events, it is the Company's intention
that the participants in the ESOP will receive the entire benefit of the
Remaining Shares which are unallocated after application of the above
provisions.
 
  12. SERP. Notwithstanding paragraph 6 hereof, the Seller's SERP will
continue in effect following the Effective Time for the benefit of the current
participants therein.
 
                                     A-43
<PAGE>
 
  The Seller's SERP may be amended to provide that (a) in addition to any
existing restrictions on amendment and termination, the SERP shall not be
terminated or amended in any manner adverse to participants who are
participants as of the date hereof (b) a participant who retires at or after
age 55 may elect to defer the commencement of benefits under the SERP until
age 62 so long as the present value of the benefit at age 62 (discounted to
any earlier age at the rate of 4% per year) is not greater than the present
value of such benefit at such earlier age and (c) in calculating the benefits
thereunder, any benefit enhancements under Seller's qualified pension plan
after the date hereof shall be disregarded.
 
  13. Non-Employee Director Retirement Plan. Seller's Non-Employee Director
Retirement Plan may be amended to provide that (a) in addition to any existing
restrictions on amendment and termination, the Non-Employee Director
Retirement Plan shall not be terminated or amended in any manner adverse to
participants who are participants as of the date hereof, and (b) a participant
who retires at or after age 55 may elect to defer the commencement of benefits
under the Non-Employee Director Retirement Plan until age 62. In addition, the
Non-Employee Director Retirement Plan shall be amended (with the consent of
participants given as of the time of execution of the Merger Agreement) as
described in the last sentence of Paragraph 9 hereof (except that cash
credited to a participant's account shall not thereafter be credited with
interest).
 
  14. Annual Incentive Plan. For fiscal 1997, participants in the Seller's
Annual Incentive Plan will receive a target bonus payment and for that portion
of fiscal 1998 ending on the earlier of (a) a participant's termination of
employment or (b) December 31, 1997, participants will receive a prorated
portion of the target bonus payment based on the number of full months which
have elapsed during such period. The target bonus percentages established by
the Seller will be consistent with Seller's past practice.
 
  15. Bonuses. Bonuses for employees of the Seller and Seller Subsidiaries
other than those participating in the Annual Incentive Plan for fiscal 1997
shall be paid pursuant to the terms of any such bonus plans, or in the absence
of a plan, consistent with past practice of Seller and Seller Subsidiaries,
except that any other bonus amounts which, in a manner consistent with past
practice, have been accrued as of the end of fiscal 1997, may also be paid.
All bonuses in respect of fiscal 1998 which, in a manner consistent with past
practice, are accrued but unpaid as of the Effective Time shall be paid
promptly following the Effective Time.
 
  16. Amendments. The Company agrees that the Seller shall be permitted, prior
to the Effective Time to make the amendments to, and to take such other
actions with respect to, its plans and agreements, as described herein.
 
  17. Employee Loan Program. Each Affected Employee will have the ability to
retain any loan, under its existing terms and conditions, provided to such
employee under the Seller's Employee Loan Program until its maturity. Any
outstanding loan under the Employee Loan Program of any employee of Seller or
the Seller Subsidiaries whose employment is terminated following the Effective
Time will be refinanced by the Company, under the loan program of the Company
in a standard loan product provided by the Company at that time, at the then
prevailing rate of interest made available to employees of the Company, unless
the employee's credit history does not meet the Company's standard loan
criteria. The fact that the employee has been severed will not be taken into
account in determining whether the employee satisfies the Company's standard
loan criteria.
 
                                     A-44
<PAGE>
 
                                   AGREEMENT
 
  This Agreement is entered into as of the 14th day of March 1997 by and among
("Employee"), Security Capital Corporation ("Seller"), Security Bank, S.S.B.
("Bank") and Marshall & Ilsley Corporation ("Company").
 
                                   PREAMBLE:
 
  In connection with the proposed merger of Seller with and into Company (the
"Merger") pursuant to that certain Agreement and Plan of Merger dated as of
the date hereof (the "Merger Agreement"), and in order to induce Company and
Seller to execute the Merger Agreement, Employee, as the holder of an option
or options to purchase Seller's common stock (the "Options"), and as a
signatory to an Employment Agreement with Seller or one of its subsidiaries,
hereby agrees as follows:
 
  1. Non-qualified Options. Subject to Seller's right to waive this provision
consistent with the terms of the Merger Agreement, Employee agrees not to
exercise that portion of his Options to purchase Seller's common stock to the
extent such options are nonqualified stock options ("NSOs"). All NSOs shall be
surrendered at the Effective Time in exchange for a cash payment equal to the
excess of the Average Per Share Consideration, as defined in the Merger
Agreement, over the exercise price for the Options times the number of shares
covered by the NSOs. The cash proceeds will be reduced by any applicable
withholding. No option holder shall exercise any Option after the date which
is five calendar days prior to the Effective Time of the Merger, provided that
incentive stock options ("ISOs") may be exercised after the Effective Time of
the Merger. The Company will give notice to the option holder of the expected
Effective Time at least fifteen calendar days prior to such Effective Time.
Employee agrees, to the extent he has transferred Options, that he will use
his best efforts to get the transferee(s) of such Options to execute an
agreement, dated as of the date hereof, whereby such transferee(s) will agree
to the same restrictions on his/their options as contained in this Paragraph
1.
 
  2. Amendment to Employment Agreement. Employee agrees to the following
amendments to the Employment Agreement between Employee, Seller and Seller's
bank subsidiary (the "Bank").
 
    (a) Section 5(vii)(A) is hereby amended to (i) delete that portion
  beginning with "the Executive's Total Compensation" through the end of the
  sentence and (ii) add "an amount equal to Gross Compensation within the
  meaning of the Seller's Group Life Insurance Plan for the last calendar
  year preceding the Termination Date. Notwithstanding the foregoing, the
  total amount paid pursuant to this Section 5(vii)(A) will be the lesser of
  (a) the Severance Amount contained in the Change of Control Severance
  Benefits schedule prepared by Seller on March 7, 1997 and provided to
  Company; provided, however, that in the case of Messrs. William G. Schuett,
  Sr., Robert A. Schaefer, and Joseph Schoendorf, this will be 50% of the
  amount reflected on such schedule; or (b) an amount which, when added to
  the other "parachute payments' (within the meaning of Section 280G(b)(2)(A)
  of the Internal Revenue Code of 1986 as amended (the "Code")) which result
  from the "change in control,' equals One Dollar less than 3 times the 'base
  amount' as defined in Code Section 280G(d)(2)."
 
    (b) For purposes of determining the amount payable to Employee under
  Section 5(vii)(B) of the Employment Agreement, if Employee receives credit
  under one or more of the Plans, as defined therein, for retirement benefits
  through December 31, 1997, he shall not be entitled to a payment in
  addition thereto under Section 5(vii)(B) of the Employment Agreement.
 
    (c) Section 6 of the Employment Agreement is deleted in its entirety and
  a new Section 6 is inserted therefor.
 
    "6. Payments Upon a "Change in Control". Payments under Section 5(vii)
    hereof, as amended, shall be made in a lump sum within thirty days of
    the change in control even if the Executive's employment has not
    terminated and even if the Employment Term has expired provided that
    the Executive (i) is employed by Seller or one of its subsidiaries at
    the Effective Time and (ii) executes a complete and permanent release
    of all claims arising out of his employment, including age
    discrimination (but not
 
                                     A-45
<PAGE>
 
    including any vested accrued benefits under the Seller's or Bank's
    qualified or nonqualified retirement or profit sharing plans), and does
    not revoke the release within the statutory period for revocation.
 
    The payments to be made to the Executive hereunder will be reduced by
    any Federal, State, or local withholding or other taxes or charges as
    required under applicable law, and all amounts payable to the Executive
    hereunder are stated before any such deduction. Furthermore, none of
    the payments hereunder shall be included as compensation for purposes
    of any pension, deferred compensation, or welfare benefit plan or
    program of Seller, Bank, or Company, whether qualified or
    nonqualified."
 
  3. Reliance. Employee acknowledges that Seller and Company are taking
various actions, including, without limitation, signing the Merger Agreement
and expending significant amounts of money to pursue the Merger, in reliance
upon this Agreement.
 
  4. Choice of Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Wisconsin.
 
  In Witness Whereof, the undersigned have executed this Agreement as of the
date set forth above.
 
                                          Employee:
 
 
                                          -------------------------------------
 
                                          Security Capital Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Security Bank, S.S.B.
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Marshall & Ilsley Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                     A-46
<PAGE>
 
                                   AGREEMENT
 
  This Agreement is entered into as of the 14th day of March 1997 by and among
("Employee"), Security Capital Corporation ("Seller"), Security Bank, S.S.B.
("Bank") and Marshall & Ilsley Corporation ("Company").
 
                                   PREAMBLE:
 
  In connection with the proposed merger of Seller with and into Company (the
"Merger") pursuant to that certain Agreement and Plan of Merger dated as of
the date hereof (the "Merger Agreement"), and in order to induce Company and
Seller to execute the Merger Agreement, Employee, as the holder of an option
or options to purchase Seller's common stock (the "Options"), as a signatory
to an Employment Agreement with Seller or one of its subsidiaries and as a
participant in the Deferred Compensation Plan for Officers or a similar
deferred compensation arrangement, hereby agrees as follows:
 
  1. Non-qualified Options. Subject to Seller's right to waive this provision
consistent with the terms of the Merger Agreement, Employee agrees not to
exercise that portion of his Options to purchase Seller's common stock to the
extent such options are nonqualified stock options ("NSOs"). All NSOs shall be
surrendered at the Effective Time in exchange for a cash payment equal to the
excess of the Average Per Share Consideration, as defined in the Merger
Agreement, over the exercise price for the Options times the number of shares
covered by the NSOs. The cash proceeds will be reduced by any applicable
withholding. No option holder shall exercise any Option after the date which
is five calendar days prior to the Effective Time of the Merger, provided that
incentive stock options ("ISOs") may be exercised after the Effective Time of
the Merger. The Company will give notice to the option holder of the expected
Effective Time at least fifteen calendar days prior to such Effective Time.
Employee agrees, to the extent he has transferred Options, that he will use
his best efforts to get the transferee(s) of such Options to execute an
agreement, dated as of the date hereof, whereby such transferee(s) will agree
to the same restrictions on his/their options as contained in this Paragraph
1.
 
  2. Amendment to Employment Agreement. Employee agrees to the following
amendments to the Employment Agreement between Employee, Seller and Seller's
bank subsidiary (the "Bank").
 
    (a) Section 5(vii)(A) is hereby amended to (i) delete that portion
  beginning with "the Executive's Total Compensation" through the end of the
  sentence and (ii) add "an amount equal to Gross Compensation within the
  meaning of the Seller's Group Life Insurance Plan for the last calendar
  year preceding the Termination Date. Notwithstanding the foregoing, the
  total amount paid pursuant to this Section 5(vii)(A) will be the lesser of
  (a) the Severance Amount contained in the Change of Control Severance
  Benefits schedule prepared by Seller on March 7, 1997 and provided to
  Company; provided, however, that in the case of Messrs. William G. Schuett,
  Sr., Robert A. Schaefer, and Joseph Schoendorf, this will be 50% of the
  amount reflected on such schedule; or (b) an amount which, when added to
  the other "parachute payments' (within the meaning of Section 280G(b)(2)(A)
  of the Internal Revenue Code of 1986 as amended (the "Code")) which result
  from the "change in control,' equals One Dollar less than 3 times the "base
  amount' as defined in Code Section 280G(d)(2)."
 
    (b) For purposes of determining the amount payable to Employee under
  Section 5(vii)(B) of the Employment Agreement, if Employee receives credit
  under one or more of the Plans, as defined therein, for retirement benefits
  through December 31, 1997, he shall not be entitled to a payment in
  addition thereto under Section 5(vii)(B) of the Employment Agreement.
 
    (c) Section 6 of the Employment Agreement is deleted in its entirety and
  a new Section 6 is inserted therefor.
 
    "6. Payments Upon a "Change in Control". Payments under Section 5(vii)
    hereof, as amended, shall be made in a lump sum within thirty days of
    the change in control even if the Executive's employment has not
    terminated and even if the Employment Term has expired provided that
    the Executive (i) is employed by Seller or one of its subsidiaries at
    the Effective Time and (ii) executes a complete and
 
                                     A-47
<PAGE>
 
    permanent release of all claims arising out of his employment,
    including age discrimination (but not including any vested accrued
    benefits under the Seller's or Bank's qualified or nonqualified
    retirement or profit sharing plans), and does not revoke the release
    within the statutory period for revocation.
 
    The payments to be made to the Executive hereunder will be reduced by
    any Federal, State, or local withholding or other taxes or charges as
    required under applicable law, and all amounts payable to the Executive
    hereunder are stated before any such deduction. Furthermore, none of
    the payments hereunder shall be included as compensation for purposes
    of any pension, deferred compensation, or welfare benefit plan or
    program of Seller, Bank, or Company, whether qualified or
    nonqualified."
 
  3. Amendment to Deferred Compensation Plan for Officers. Employee consents
to the amendments made to the Deferred Compensation Plan for Officers or a
similar deferred compensation arrangement pursuant to Paragraph 9 of Annex B
to the Merger Agreement. Employee acknowledges receiving a copy of Annex B to
the Merger Agreement and agrees to be bound by such amendments.
 
  4. Reliance. Employee acknowledges that Seller and Company are taking
various actions, including, without limitation, signing the Merger Agreement
and expending significant amounts of money to pursue the Merger, in reliance
upon this Agreement.
 
  5. Choice of Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Wisconsin.
 
  In Witness Whereof, the undersigned have executed this Agreement as of the
date set forth above.
 
                                          Employee:
 
 
                                          -------------------------------------
 
                                          Security Capital Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Security Bank, S.S.B.
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Marshall & Ilsley Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                     A-48
<PAGE>
 
                                   AGREEMENT
 
  This Agreement is entered into as of the 14th day of March 1997 by and among
("Director"), Security Capital Corporation ("Seller"), Security Bank, S.S.B.
("Bank") and Marshall & Ilsley Corporation ("Company").
 
                                   PREAMBLE:
 
  In connection with the proposed merger of Seller with and into Company (the
"Merger") pursuant to that certain Agreement and Plan of Merger dated as of
the date hereof (the "Merger Agreement"), and in order to induce Company and
Seller to execute the Merger Agreement, Director, as the holder of an option
or options to purchase Seller's common stock (the "Options") and as a
participant in the Nonemployee Director Deferred Compensation Plan and the
Nonemployee Director Retirement Plan hereby agrees as follows:
 
  1. Non-qualified Options. Subject to Seller's right to waive this provision
consistent with the terms of the Merger Agreement, Director agrees not to
exercise his Options to purchase Seller's common stock ("NSOs"). All NSOs
shall be surrendered at the Effective Time in exchange for a cash payment
equal to the excess of the Average Per Share Consideration, as defined in the
Merger Agreement, over the exercise price for the Options times the number of
shares covered by the NSOs. No option holder shall exercise any Option after
the date which is five calendar days prior to the Effective Time of the
Merger. The Company will give notice to the option holder of the expected
Effective Time at least fifteen calendar days prior to such Effective Time.
Director agrees, to the extent he has transferred Options, that he will use
his best efforts to get the transferee(s) of such Options to execute an
agreement, dated as of the date hereof, whereby such transferee(s) will agree
to the same restrictions on his/their options as contained in this Paragraph
1.
 
  2. Amendment to Nonemployee Director Deferred Compensation Plan. Director
consents to the amendments made to the Nonemployee Director Deferred
Compensation Plan pursuant to Paragraph 10 of Annex B to the Merger Agreement.
Director acknowledges receiving a copy of Annex B to the Merger Agreement and
agrees to be bound by such amendments.
 
  3. Amendment to Nonemployee Director Retirement Plan. Director consents to
the amendments made to the Nonemployee Director Retirement Plan pursuant to
Paragraph 13 of Annex B to the Merger Agreement and agrees to be bound by such
amendments.
 
  4. Reliance. Director acknowledges that Seller and Company are taking
various actions, including, without limitation, signing the Merger Agreement
and expending significant amounts of money to pursue the Merger, in reliance
upon this Agreement.
 
  5. Choice of Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Wisconsin.
 
                                     A-49
<PAGE>
 
  In Witness Whereof, the undersigned have executed this Agreement as of the
date set forth above.
 
                                          Director:
 
 
                                          -------------------------------------
 
                                          Security Capital Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Security Bank, S.S.B.
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Marshall & Ilsley Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                      A-50
<PAGE>
 
                                   AGREEMENT
 
  This Agreement is entered into as of the 14th day of March 1997 by and among
("Employee"), Security Capital Corporation ("Seller"), Security Bank, S.S.B.
("Bank") and Marshall & Ilsley Corporation ("Company").
 
                                   PREAMBLE:
 
  In connection with the proposed merger of Seller with and into Company (the
"Merger") pursuant to that certain Agreement and Plan of Merger dated as of
the date hereof (the "Merger Agreement"), and in order to induce Company and
Seller to execute the Merger Agreement, Employee, as the holder of an option
or options to purchase Seller's common stock (the "Options"), and as a
participant in the Deferred Compensation Plan for Officers or a similar
deferred compensation arrangement, hereby agrees as follows:
 
  1. Non-qualified Options. Subject to Seller's right to waive this provision
consistent with the terms of the Merger Agreement, Employee agrees not to
exercise that portion of his Options to purchase Seller's common stock to the
extent such options are nonqualified stock options ("NSOs"). All NSOs shall be
surrendered at the Effective Time in exchange for a cash payment equal to the
excess of the Average Per Share Consideration, as defined in the Merger
Agreement, over the exercise price for the Options times the number of shares
covered by the NSOs. The cash proceeds will be reduced by any applicable
withholding. No option holder shall exercise any Option after the date which
is five calendar days prior to the Effective Time of the Merger, provided that
incentive stock options ("ISOs") may be exercised after the Effective Time of
the Merger. The Company will give notice to the option holder of the expected
Effective Time at least fifteen calendar days prior to such Effective Time.
Employee agrees, to the extent he has transferred Options, that he will use
his best efforts to get the transferee(s) of such Options to execute an
agreement, dated as of the date hereof, whereby such transferee(s) will agree
to the same restrictions on his/their options as contained in this Paragraph
1.
 
  2. Amendment to Deferred Compensation Plan for Officers. Employee consents
to the amendments made to the Deferred Compensation Plan for Officers or a
similar deferred compensation arrangement pursuant to Paragraph 9 of Annex B
to the Merger Agreement. Employee acknowledges receiving a copy of Annex B to
the Merger Agreement and agrees to be bound by such amendments.
 
  3. Reliance. Employee acknowledges that Seller and Company are taking
various actions, including, without limitation, signing the Merger Agreement
and expending significant amounts of money to pursue the Merger, in reliance
upon this Agreement.
 
  4. Choice of Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Wisconsin.
 
                                     A-51
<PAGE>
 
  In Witness Whereof, the undersigned have executed this Agreement as of the
date set forth above.
 
                                          Employee:
 
                                          -------------------------------------
 
                                          Security Capital Corporation
 
                                          By: _________________________________
 
                                          Attest: _____________________________
 
                                          Security Bank, S.S.B.
 
                                          By: _________________________________
 
                                          Attest: _____________________________
 
                                          Marshall & Ilsley Corporation
 
                                          By: _________________________________
 
                                          Attest: _____________________________
 
                                      A-52
<PAGE>
 
                                   AGREEMENT
 
  This Agreement is entered into as of the 14th day of March 1997 by and among
("Employee"), Security Capital Corporation ("Seller"), Security Bank, S.S.B.
("Bank") and Marshall & Ilsley Corporation ("Company").
 
                                   PREAMBLE:
 
  In connection with the proposed merger of Seller with and into Company (the
"Merger") pursuant to that certain Agreement and Plan of Merger dated as of
the date hereof (the "Merger Agreement"), and in order to induce Company and
Seller to execute the Merger Agreement, Employee, as the holder of an option
or options to purchase Seller's common stock (the "Options"), hereby agrees as
follows:
 
    1. Non-qualified Options. Subject to Seller's right to waive this
  provision consistent with the terms of the Merger Agreement, Employee
  agrees not to exercise that portion of his Options to purchase Seller's
  common stock to the extent such options are nonqualified stock options
  ("NSOs"). All NSOs shall be surrendered at the Effective Time in exchange
  for a cash payment equal to the excess of the Average Per Share
  Consideration, as defined in the Merger Agreement, over the exercise price
  for the Options times the number of shares covered by the NSOs. The cash
  proceeds will be reduced by any applicable withholding. No option holder
  shall exercise any Option after the date which is five calendar days prior
  to the Effective Time of the Merger, provided that incentive stock options
  ("ISOs") may be exercised after the Effective Time of the Merger. The
  Company will give notice to the option holder of the expected Effective
  Time at least fifteen calendar days prior to such Effective Time. Employee
  agrees, to the extent he has transferred Options, that he will use his best
  efforts to get the transferee(s) of such Options to execute an agreement,
  dated as of the date hereof, whereby such transferee(s) will agree to the
  same restrictions on his/their options as contained in this Paragraph 1.
 
    2. Reliance. Employee acknowledges that Seller and Company are taking
  various actions, including, without limitation, signing the Merger
  Agreement and expending significant amounts of money to pursue the Merger,
  in reliance upon this Agreement.
 
    3. Choice of Law. This Agreement shall be governed by, and construed in
  accordance with, the laws of the State of Wisconsin.
 
                                     A-53
<PAGE>
 
  In Witness Whereof, the undersigned have executed this Agreement as of the
date set forth above.
 
                                          Employee:
 
                                          -------------------------------------
 
                                          Security Capital Corporation
 
                                          By: _________________________________
 
                                          Attest: _____________________________
 
                                          Security Bank, S.S.B.
 
                                          By: _________________________________
 
                                          Attest: _____________________________
 
                                          Marshall & Ilsley Corporation
 
                                          By: _________________________________
 
                                          Attest: _____________________________
 
                                      A-54
<PAGE>
 
                                   AGREEMENT
 
  This Agreement is entered into as of the 14th day of March 1997 by and among
("Option Holder"), Security Capital Corporation ("Seller"), Security Bank,
S.S.B. ("Bank") and Marshall & Ilsley Corporation ("Company").
 
                                   PREAMBLE:
 
  In connection with the proposed merger of Seller with and into Company (the
"Merger") pursuant to that certain Agreement and Plan of Merger dated as of
the date hereof (the "Merger Agreement"), and in order to induce Company and
Seller to execute the Merger Agreement, Option Holder, as the holder of an
option or options to purchase Seller's common stock (the "Options"), hereby
agrees as follows:
 
  1. Non-qualified Options. Subject to Seller's right to waive this provision
consistent with the terms of the Merger Agreement, Option Holder agrees not to
exercise his Options to purchase Seller's common stock. All Options shall be
surrendered at the Effective Time in exchange for a cash payment equal to the
excess of the Average Per Share Consideration, as defined in the Merger
Agreement, over the exercise price for the Options times the number of shares
covered by the Options. The cash proceeds will be reduced by any applicable
withholding. No Option Holder shall exercise any Option after the date which
is five calendar days prior to the Effective Time of the Merger. The Company
will give notice to the Option Holder of the expected Effective Time at least
fifteen calendar days prior to such Effective Time.
 
  2. Reliance. Option Holder acknowledges that Seller and Company are taking
various actions, including, without limitation, signing the Merger Agreement
and expending significant amounts of money to pursue the Merger, in reliance
upon this Agreement.
 
  3. Choice of Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Wisconsin.
 
  In Witness Whereof, the undersigned have executed this Agreement as of the
date set forth above.
 
                                          Option Holder:
 
 
                                          -------------------------------------
 
                                          Security Capital Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Security Bank, S.S.B.
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                          Marshall & Ilsley Corporation
 
 
                                          By: _________________________________
 
 
                                          Attest: _____________________________
 
                                     A-55
<PAGE>
 
                                  INDEX GROUP
 
<TABLE>
<CAPTION>
                                                                       WEIGHTING
COMPANY                                                                 FACTOR
- -------                                                                ---------
<S>                                                                    <C>
AmSouth Bancorporation................................................    4.44%
Bancorp Hawaii, Inc...................................................    2.79
Crestar Financial Corporation.........................................    3.07
First of America Bank Corp............................................    5.97
First Security Corporation............................................    4.07
First Tennessee National Corporation..................................    4.75
Firstar Corporation...................................................    3.46
Huntington Bancshares, Inc............................................    6.27
Mercantile Bancorporation Inc.........................................    6.79
Northern Trust Corporation............................................    7.18
Old Kent Financial Corporation........................................    3.49
Regions Financial Corporation.........................................    6.06
SouthTrust Corporation................................................    5.65
Southern National Corporation.........................................    8.45
Star Banc Corporation.................................................    5.64
Summit Bancorp........................................................    8.38
Synovus Financial Corp................................................    6.49
Union Planters Corporation............................................    4.69
Wilmington Trust Corporation..........................................    2.39
                                                                        ------
    Total.............................................................  100.00%
                                                                        ======
</TABLE>
 
                                      A-56
<PAGE>
 
                                                                     APPENDIX B
 
ILLUSTRATIVE CALCULATIONS OF STOCK CONSIDERATION, CASH CONSIDERATION, MIXED
CONSIDERATION AND STOCK AMOUNT
 
ILLUSTRATION OF CALCULATIONS OF STOCK CONSIDERATION, CASH CONSIDERATION, MIXED
  CONSIDERATION AND STOCK AMOUNT AT DIFFERENT VALUATION PERIODS MARKET VALUES
    FOR M&I COMMON STOCK (AS SUCH TERMS ARE DEFINED IN THE PROXY STATEMENT-
                                  PROSPECTUS)
 
 This illustration assumes that 9,090,232 shares of Security Common Stock will
              be outstanding at the end of the Valuation Period.
 
 
  There can be no assurance as to what the Valuation Period Market Values for
M&I Common Stock will be or what the value of M&I Common Stock to be issued in
the Merger will be at or following the Effective Time. See "THE MERGER--Merger
Consideration."
 
<TABLE>
<CAPTION>
                                                                       ELECTION 1                               ELECTION 2
                                                                   MIXED ELECTION (B)                      ALL CASH ELECTION (C)
                                              ------------------------------------------------------------ ---------------------
                                                                              VALUE OF M&I
   ALUATION PERIOD (A)V          AVERAGE                                         STOCK
    MARKET VALUE OF             PER SHARE           CASH          M&I STOCK    AMOUNT PER
 M& COMMON STOCK ($)(A)I    CONSIDERATION ($) CONSIDERATION ($) CONSIDERATION  SHARE ($)   TOTAL VALUE ($)   CONSIDERATION ($)
- -----------------------     ----------------- ----------------- ------------- ------------ --------------- ---------------------
   <S>                      <C>               <C>               <C>           <C>          <C>             <C>
     32.00...........             84.80             41.40          1.3561        43.40          84.80              84.80
     32.50...........             85.47             41.40          1.3561        44.07          85.47              85.47
     33.00...........             86.15             41.40          1.3561        44.75          86.15              86.15
     33.50...........             86.83             41.40          1.3561        45.43          86.83              86.83
     34.00...........             87.51             41.40          1.3561        46.11          87.51              87.51
     34.50...........             88.19             41.40          1.3561        46.79          88.19              88.19
     35.00...........             88.86             41.40          1.3561        47.46          88.86              88.86
     35.50...........             89.54             41.40          1.3561        48.14          89.54              89.54
     36.00...........             90.22             41.40          1.3561        48.82          90.22              90.22
     36.50...........             90.90             41.40          1.3561        49.50          90.90              90.90
     37.00...........             91.58             41.40          1.3561        50.18          91.58              91.58
<CAPTION>
                                    ELECTION 3
                              ALL STOCK ELECTION (C)
                            --------------------------
                                          VALUE OF M&I
   ALUATION PERIOD (A)V                      STOCK
    MARKET VALUE OF           M&I STOCK    AMOUNT PER
 M& COMMON STOCK ($)(A)I    CONSIDERATION  SHARE ($)
- -----------------------     ------------- ------------
   <S>                      <C>           <C>
     32.00...........          2.6499        84.80
     32.50...........          2.6299        85.47
     33.00...........          2.6106        86.15
     33.50...........          2.5919        86.83
     34.00...........          2.5737        87.51
     34.50...........          2.5561        88.19
     35.00...........          2.5390        88.86
     35.50...........          2.5223        89.54
     36.00...........          2.5061        90.22
     36.50...........          2.4903        90.90
     37.00...........          2.4750        91.58
  37.3125.........             92.00             41.40          1.3561        50.60          92.00              92.00
  37.3125.........          2.4657        92.00
  37.50...........             92.25             41.40          1.3561        50.85          92.25              92.25
  38.00...........             92.93             41.40          1.3561        51.53          92.93              92.93
  38.50...........             93.61             41.40          1.3561        52.21          93.61              93.61
  39.00...........             94.29             41.40          1.3561        52.89          94.29              94.29
  39.50...........             94.97             41.40          1.3561        53.57          94.97              94.97
  40.00...........             95.64             41.40          1.3561        54.24          95.64              95.64
  40.50...........             96.32             41.40          1.3561        54.92          96.32              96.32
  41.00...........             97.00             41.40          1.3561        55.60          97.00              97.00
  41.50...........             97.68             41.40          1.3561        56.28          97.68              97.68
  42.00...........             98.36             41.40          1.3561        56.96          98.36              98.36
  37.50...........          2.4601        92.25
  38.00...........          2.4456        92.93
  38.50...........          2.4314        93.61
  39.00...........          2.4176        94.29
  39.50...........          2.4042        94.97
  40.00...........          2.3911        95.64
  40.50...........          2.3783        96.32
  41.00...........          2.3659        97.00
  41.50...........          2.3537        97.68
  42.00...........          2.3418        98.36
</TABLE>
- ----
Assumptions:
(a) Determined based on the average final bid and ask quotations for M&I
    Common Stock for the ten consecutive trading days ending on the fifth
    calendar day prior to the Effective Time. The Valuation Period Market
    Values set forth in the chart have been included for representative
    purposes only. The Valuation Period Market Values set forth in the chart
    could be more than $42.00 or less than $32.00 per share.
(b) Mixed Elections will be given first priority.
(c) All Cash Elections and all Stock Elections will be apportioned on a pro
    rata basis. See "THE MERGER--Merger Consideration."
(1) The aggregate Merger Consideration equals 12,327,390 shares of M&I Common
    Stock and $376,335,605 cash.
(2) No oversubscriptions of either M&I Common Stock or cash.
<PAGE>
 
                                                                     APPENDIX C
 
                              [Baird Letterhead]
                                                                 March 14, 1997
 
Board of Directors
Security Capital Corporation
184 West Wisconsin Avenue
Milwaukee, Wisconsin 53203
 
Gentlemen:
 
  Security Capital Corporation (the "Company") proposes to enter into an
Agreement and Plan of Merger (the "Agreement") with Marshall & Ilsley
Corporation ("M&I"). Pursuant to the Agreement, at the Effective Time (as
defined in the Agreement), the Company will be merged with and into M&I (the
"Merger") and each outstanding share of common stock, par value $1.00 per
share ("Security Common Stock"), of the Company will be converted solely into
the right to receive the Merger Consideration (as hereinafter defined). The
"Merger Consideration" means, at the election of the holder of Security Common
Stock and subject to the terms and conditions set forth in Section 1.7 of the
Agreement (capitalized terms used herein without definition have the meanings
assigned to them in the Agreement): (i) an amount in cash equal to the Average
Per Share Consideration; (ii) a number of shares of common stock, par value
$1.00 per share ("M&I Common Stock"), of M&I equal to the Per Share Stock
Consideration; or (iii) both (A) a number of shares of M&I Common Stock equal
to (1) the Per Share Stock Consideration, multiplied by (2) the Stock
Percentage and (B) an amount in cash equal to (1) the Average Per Share
Consideration, multiplied by (2) the Cash Percentage.
 
  You have requested our opinion as to the fairness, from a financial point of
view, of the Merger Consideration to the holders of the Security Common Stock
(other than M&I and its affiliates).
 
  Robert W. Baird & Co. Incorporated ("Baird"), as part of its investment
banking business, is engaged in the evaluation of businesses and their
securities in connection with mergers and acquisitions, negotiated
underwritings, competitive biddings, secondary distribution of listed and
unlisted securities, private placements, and valuations for estate, corporate
and other purposes. We are familiar with the Company, having provided certain
investment banking services to the Company from time to time and having acted
as its financial advisor in connection with, and having participated in
certain of the negotiations leading to, the Agreement.
 
  In conducting our investigation and analysis and in arriving at our opinion
herein, we have, reviewed such information and taken into account such
financial and economic factors as we have deemed relevant under the
circumstances. In that connection, we have among other things: (i) reviewed
certain internal information, primarily financial in nature, including
projections concerning the business of operations of the Company and M&I
furnished to us for purposes of our analysis, as well as publicly available
information, including, but not limited to, the Company's and M&I's recent
filings with the Securities and Exchange Commission and equity analyst
research reports prepared by various investment banking firms including Baird;
(ii) reviewed the draft Agreement in the form presented to the Company's Board
of Directors; (iii) compared the historical market prices and trading activity
of the Security Common Stock and the M&I Common Stock with those of certain
other publicly traded companies we deemed relevant; (iv) compared the
financial position and operating results of the Company and M&I with those of
other publicly traded companies we deemed relevant; (v) compared the proposed
financial terms of the Merger with the financial terms of certain other
business combination transactions
<PAGE>
 
involving thrift institutions that we deemed relevant; and (vi) reviewed the
potential pro forma effects of the Merger on M&I. We have held discussions
with members of the Company's and M&I's respective senior management
concerning the Company's and M&I's historical and current financial condition
and operating results, as well as the future prospects of the Company and M&I,
respectively. As part of our engagement, we were requested to and did solicit
third party indications of interest in acquiring the Company. We have also
considered such other information, financial studies, analysis and
investigations and financial, economic and market criteria which we deemed
relevant for the preparation of this opinion.
 
  In arriving at our opinion, we have assumed and relied upon the accuracy and
completeness of all of the financial and other information that was publicly
available or provided to us by or on behalf of the Company and M&I, and have
not been engaged to independently verify any such information. We have
assumed, with your consent, (i) that all material assets and liabilities
(contingent or otherwise, know or unknown) of the Company and M&I are as set
forth in the Company's and M&I's respective financial statements, (ii) the
Merger will be accounted for under the purchase method of accounting and (iii)
the Merger will be consummated in accordance with the terms of the Agreement
without any amendment thereto or waiver by the Company or M&I of any condition
to their respective obligations. We have also assumed that the financial
forecasts examined by us were reasonably prepared on bases reflecting the best
available estimates and good faith judgments of the Company's and M&I's
respective senior managements as to future performance of the Company and M&I,
respectively. In conducting our review, we have not undertaken nor obtained an
independent evaluation or appraisal of any of the assets or liabilities
(contingent or otherwise) of the Company or M&I, nor have we made a physical
inspection of the properties or facilities of the Company or M&I. Our opinion
necessarily is based upon economic, monetary and market conditions as they
exist and can be evaluated on the date hereof, and does not predict or take
into account any changes which may occur, or information which may become
available, after the date hereof. Furthermore, we express no opinion as to the
price or trading range at which the Company's or M&I's securities will trade
following the date hereof.
 
  Our opinion has been prepared at the request and for the information of the
Board of Directors of the Company, and shall not be used for any other purpose
or disclosed to any other party without the prior written consent of Baird;
provided, however, that this letter may be reproduced in full in the Proxy
Statement-Prospectus to be provided to the holders of Security Common Stock in
connection with the Merger. This opinion does not address the relative merits
of the Merger and any other potential transactions or business strategies
considered by the Company's Board of Directors, and does not constitute a
recommendation to any shareholder of the Company as to how any such
shareholder should vote with respect to the Merger. Baird will receive a fee
for rendering this opinion. In the past, we have provided investment banking
services to the Company and M&I, including acting as managing underwriter of
the initial public offering of the Security Common Stock in 1993, acting as
co-manager of public offering of subordinated notes of M&I in 1993 and 1995
and acting as co-manager in the public offering of M&I's Capital Trust Pass-
Through Securities in 1996, for which we received our customary compensation.
 
  In the ordinary course of our business, we may from time-to-time trade the
securities of the Company or M&I for our own account or the accounts of our
customers and, accordingly, may at any time hold long or short positions in
such securities. In addition, Northwestern Mutual Life Insurance Company, the
parent company of Baird, beneficially owns approximately 8.97 percent of the
outstanding shares of M&I Common Stock.
 
  Based upon and subject to the foregoing, we are of the opinion that, as of
the date hereof, the Merger Consideration is fair, from a financial point of
view, to the holders of Security Common Stock (other than M&I and its
affiliates).
 
                                          Very truly yours,
 
                                          Robert W. Baird & Co. Incorporated
 
 
                                          By: _________________________________
                                                  Ronald J. Kruszewski
                                                    Managing Director
<PAGE>
 
                                    PART II
 
                    INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 20. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
  Sections 180.0850 to 180.0859 of the Wisconsin Statutes require a
corporation to indemnify any director or officer who is a party to any
threatened, pending or completed civil, criminal, administrative or
investigative action, suit, arbitration or other proceeding, whether formal or
informal, which involves foreign, federal, state or local law and which is
brought by or in the right of the corporation or by any other person. A
corporation's obligation to indemnify any such person includes the obligation
to pay any judgment, settlement, penalty, assessment, forfeiture or fine,
including any excise tax assessed with respect to an employee benefit plan,
and all reasonable expenses including fees, costs, charges, disbursements,
attorney's and other expenses except in those cases in which liability was
incurred as a result of the breach or failure to perform a duty which the
director or officer owes to the corporation and the breach or failure to
perform constitutes: (i) a willful failure to deal fairly with the corporation
or its shareholders 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 person has reasonable cause to believe his conduct was lawful or
had no reasonable cause to believe his conduct was unlawful; (iii) a
transaction from which the person derived an improper personal profit; or (iv)
willful misconduct.
 
  Unless otherwise provided in a corporation's articles of incorporation or
bylaws or by written agreement, an officer or director seeking indemnification
is entitled to indemnification if approved in any of the following manners:
(i) by majority vote of a disinterested quorum of the board of directors, or
if such quorum of disinterested directors cannot be obtained, by a majority
vote of a committee of two or more disinterested directors; (ii) by
independent legal counsel; (iii) by a panel of three arbitrators; (iv) by
affirmative vote of shareholders; (v) by a court; or (vi) with respect to any
additional right to indemnification granted by any other method permitted in
Section 180.0858 of the Wisconsin Statutes.
 
  Reasonable expenses incurred by a director or officer who is a party to a
proceeding may be reimbursed by a corporation at such time as the director or
officer furnishes to the corporation written affirmation of his good faith
belief that he has not breached or failed to perform his duties and a written
undertaking to repay any amounts advanced if it is determined that
indemnification by the corporation is not required.
 
  The indemnification provisions of Sections 180.0850 to 180.0859 are not
exclusive. A corporation may expand an officer's or director's right to
indemnification (i) in its articles of incorporation or by-laws; (ii) by
written agreement; (iii) by resolution of its board of directors; or (iv) by
resolution of a majority of all of the corporation's voting shares then issued
and outstanding.
 
  As permitted by Section 180.0858, M&I has adopted indemnification provisions
in its Bylaws which closely track the statutory indemnification provisions
with certain exceptions. In particular, Section 7.1 of M&I's Bylaws, among
other items, provides that (i) any individual shall be indemnified unless it
is proven by a final judicial adjudication that indemnification is prohibited
and (ii) payment or reimbursement of expenses, subject to certain limitations,
will be mandatory rather than permissive. M&I has purchased directors' and
officers' liability insurance which insures M&I's officers and directors
against certain liabilities which may arise under the Securities Act of 1933.
 
                                     II-1
<PAGE>
 
ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES
 
  (a) Exhibits.
 
<TABLE>
<CAPTION>
      NO.  DESCRIPTION
      ---  -----------
 <C>       <S>
           Agreement and Plan of Merger (included as Appendix A to the Proxy
       2   Statement-Prospectus)
       5   Opinion of Godfrey & Kahn, S.C.
           Opinion of Godfrey & Kahn, S.C. as to certain federal income tax
       8.1 matters
      10.1 Amendment to Employment Agreement of Robert A. Schaefer (included in
           Annex B to Appendix A to the Proxy Statement-Prospectus)
      23.1 Consent of Arthur Andersen LLP
      23.2 Consent of KPMG Peat Marwick LLP
      23.3 Consent of Godfrey & Kahn, S.C. (included in Exhibits 5 and 8.1)
      23.4 Consent of Robert W. Baird & Co. Incorporated
      24   Powers of Attorney
      99.1 Form of Proxy for the Security Special Meeting of Shareholders
      99.2 Rule 438 Consent of Robert A. Schaefer
</TABLE>
 
  (b) Financial Statement Schedules. No financial schedules are required to be
filed with regard to M&I or Security.
 
  (c) Fairness Opinion. The information required by this Item is included as
part of the Prospectus.
 
ITEM 22. UNDERTAKINGS
 
  The 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; and (iii) to
include any material information with respect to the plan of distribution not
previously disclosed in the registration statement or any material information
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; and
 
  (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.
 
  (4) 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 (and, where
applicable, each filing of an employee benefit plan's annual report pursuant
to 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.
 
                                     II-2
<PAGE>
 
  (5) Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
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 therefore is unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer of controlling
person of the 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, the 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.
 
  (6) The undersigned Registrant hereby undertakes to respond to requests for
information that is incorporated by reference into the Prospectus pursuant to
Item 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.
 
  (7) The undersigned Registrant hereby undertakes to supply by means of post-
effective amendment all information concerning a transaction, and the company
being acquired or involved therein, that was not the subject of and included
in the registration statement when it became effective.
 
  (8) The undersigned Registrant hereby undertakes as follows: prior to any
public reoffering of the securities registered hereunder through use of a
prospectus which is a 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 Registrant 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.
 
  (9) The Registrant undertakes that every prospectus (i) that is filed
pursuant to paragraph (8) immediately preceding, or (ii) that purports to meet
the requirements of section 10(a)(3) of the Securities Act of 1933 and is used
in connection with an offering of securities subject to Rule 415, will be
filed as a part of an 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.
 
                                     II-3
<PAGE>
 
                                  SIGNATURES
 
  PURSUANT TO REQUIREMENTS OF THE SECURITIES ACT OF 1933, THE REGISTRANT HAS
DULY CAUSED THIS REGISTRATION STATEMENT ON FORM S-4 TO BE SIGNED ON ITS BEHALF
BY THE UNDERSIGNED, THEREUNTO DULY AUTHORIZED, IN THE CITY OF MILWAUKEE, STATE
OF WISCONSIN, ON JUNE 6, 1997.
 
                                          Marshall & Ilsley Corporation
                                                   (Registrant)
 
                                                    /s/ J.B. Wigdale
                                          By: _________________________________
                                                       J.B. WIGDALE
                                                   Chairman of the Board
 
  PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, THIS PRE-
EFFECTIVE AMENDMENT TO REGISTRANT'S REGISTRATION STATEMENT ON FORM S-4 HAS
BEEN SIGNED BY THE FOLLOWING PERSONS IN THE CAPACITIES AND ON THE DATE
INDICATED.
 
              SIGNATURE                        TITLE                 DATE
 
         /s/ J.B. Wigdale              Chairman of the           June 6, 1997
- -------------------------------------   Board and a
            J.B. WIGDALE                Director (Chief
                                        Executive Officer)
 
      /s/ G.H. Gunnlaugsson            Executive Vice            June 6, 1997
- -------------------------------------   President and a
          G.H. GUNNLAUGSSON             Director (Chief
                                        Financial Officer)
 
       /s/ P.R. Justiliano             Senior Vice               June 6, 1997
- -------------------------------------   President and
           P.R. JUSTILIANO              Corporate
                                        Controller
                                        (Principal
                                        Accounting Officer)
 
                  *                    Director
- -------------------------------------
          RICHARD A. ABDOO
 
                  *                    Director
- -------------------------------------
           OSCAR C. BOLDT
 
                  *                    Director
- -------------------------------------
             J.P. BOLDUC
 
                                       Director
- -------------------------------------
          WENDELL F. BUECHE
 
                  *                    Director
- -------------------------------------
            JON F. CHAIT
 
                  *                    Director
- -------------------------------------
          GLENN A. FRANCKE
 
                  *                    Director
- -------------------------------------
          G.H. GUNNLAUGSSON
       
                                     II-4
<PAGE>
 
              SIGNATURE                         TITLE                DATE
 
                  *                     Director
- -------------------------------------
         BURLEIGH E. JACOBS
 
                  *                     Director
- -------------------------------------
           JACK F. KELLNER
 
                  *                     Director
- -------------------------------------
           JAMES F. KRESS
 
                  *                     Director
- -------------------------------------
            D.J. KUESTER
 
                  *                     Director
- -------------------------------------
        EDWARD L. MEYER, JR.
 
                  *                     Director
- -------------------------------------
            DON R. O'HARE
 
                  *                     Director
- -------------------------------------
           SAN W. ORR, JR.
 
                  *                     Director
- -------------------------------------
        PETER M. PLATTEN, III
 
                                        Director
- -------------------------------------
           J.A. PUELICHER
 
                  *                     Director
- -------------------------------------
          STUART W. TISDALE
 
                  *                     Director
- -------------------------------------
            J.B. WIGDALE
 
                  *                     Director
- -------------------------------------
           JAMES O. WRIGHT
 
                  *                     Director
- -------------------------------------
           GUS A. ZUEHLKE
 
        /s/ M.A. Hatfield               As Attorney-in-Fact*     June 6, 1997
- -------------------------------------
            M.A. HATFIELD
- --------
* Pursuant to authority granted by powers of attorney, copies of which are
  filed herewith.
 
                                      II-5
<PAGE>
 
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
  EXHIBIT
    NO.    EXHIBIT
  -------  -------
 <C>       <S>
  2        Agreement and Plan of Merger (included as Appendix A to the Proxy
           Statement-Prospectus)
  5        Opinion of Godfrey & Kahn, S.C.
  8.1      Opinion of Godfrey & Kahn, S.C. as to certain federal income tax
           matters
 10.1      Amendment to Employment Agreement of Robert A. Schaefer (included in
           Annex B to Appendix A to the Proxy Statement-Prospectus)
 23.1      Consent of Arthur Andersen LLP
 23.2      Consent of KPMG Peat Marwick LLP
 23.3      Consent of Godfrey & Kahn, S.C. (included in Exhibits 5 and 8.1)
 23.4      Consent of Robert W. Baird & Co. Incorporated
 24        Powers of Attorney
 99.1      Form of Proxy for the Security Special Meeting of Shareholders
 99.2      Rule 438 Consent of Robert A. Schaefer
</TABLE>

<PAGE>
 
                                                                      EXHIBIT 5
 
                                                                   June 6, 1997
 
Marshall & Ilsley Corporation
770 North Water Street
Milwaukee, WI 53202
 
Ladies and Gentlemen:
 
  Reference is made to the Registration Statement on Form S-4 (the
"Registration Statement") to be filed by Marshall & Ilsley Corporation (the
"Corporation") with the Securities and Exchange Commission (the "Commission")
pursuant to the Securities Act of 1933, as amended (the "Securities Act") with
respect to shares of common stock of the Corporation, $1.00 par value ("Common
Stock") issuable in connection with the merger (the "Merger") of the
Corporation and Security Capital Corporation, as described in the Proxy
Statement-Prospectus included in the Registration Statement.
 
  As counsel to the Corporation, we are familiar with the Restated Articles of
Incorporation and the By-laws of the Corporation. We have also examined, or
caused to be examined, such other documents and instruments and have made, or
caused to be made, such further investigation as we have deemed necessary or
appropriate to enable us to render this opinion.
 
  Based upon the foregoing, it is our opinion that the shares of Common Stock
of the Corporation when issued upon the effectiveness of the Merger and
delivered to the holders of common stock of Security Capital Corporation will
be legally issued, fully paid and nonassessable, except that Section 180.0622
of the Wisconsin Business Corporation Law, and judicial interpretations
thereof, impose liability upon shareholders for unpaid wage claims of the
Corporation's employees not exceeding six months service in any one case.
 
  We hereby consent to the use of this opinion as Exhibit 5 to the
Registration Statement and we further consent to the use of our name in the
Registration Statement under the caption "OPINIONS." In giving this consent,
we do not admit that we are in the category of persons whose consent is
required under Section 7 of the Securities Act or the rules and regulations of
the Commission issued thereunder.
 
                                          Godfrey & Kahn, S.C.

<PAGE>

                                                                     EXHIBIT 8.1






                                June 6, 1997
        


Marshall & Ilsley Corporation
770 North Water Street
Milwaukee, WI 53202

     RE:  Proxy Statement - Prospectus of Security Capital Corporation and
          Marshall & Ilsley Corporation Regarding Proposed Merger of Security
          Capital Corporation with Marshall & Ilsley Corporation


Ladies and Gentlemen:


     We are acting as counsel for Marshall & Ilsley Corporation ("M&I") in
connection with the filing with the Securities and Exchange Commission of the
Proxy Statement - Prospectus (the "Proxy Statement") relating to the proposed
merger (the "Merger") of Security Capital Corporation ("Security"), a Wisconsin
corporation, with and into M&I, a Wisconsin corporation, pursuant to an
Agreement and Plan of Merger, dated as of March 14, 1997, by and among Security 
and M&I (the "Agreement").

      For purposes of the opinion set forth below, we have relied, with the 
consent of M&I and the consent of Security, upon the accuracy and completeness 
of the statements and representations (which statements and representations we 
have neither investigated nor verified) contained, respectively, in the 
certificates of the officers of M&I and Security (copies of which are 
incorporated herein by reference) and have assumed that such certificates will 
be complete and accurate as of the Effective Time.  We have also relied upon the
accuracy of the Proxy Statement.  Any capitalized term used and not defined 
herein has the meaning given to it in the Proxy Statement or the appendices 
thereto (including the Agreement).

      We have also assumed that the transactions contemplated by the Agreement 
will be consummated in accordance therewith and as described in the Proxy 
Statement and that the Merger will qualify as a statutory merger under the 
applicable laws of the State of Wisconsin.

      Based upon and subject to the foregoing, the discussion contained in the 
Proxy Statement under the caption "THE MERGER - Certain Federal Income Tax 
Consequences of the Merger",
<PAGE>
 
Marshall & Ilsley Corporation
June 6, 1997
Page 2


represents our opinion as to the material federal income tax consequences of the
Merger under currently applicable law.

        This opinion is limited to the federal law of the United States and 
administrative rulings of the Internal Revenue Service as in effect on the date 
hereof.  We have no obligation to advise you or any other person of changes in 
law or in the administrative rulings of the Internal Revenue Service that occur
after the date hereof. Further, our opinion is not, nor should it be construed
or relied upon as, a guaranty, nor is it in any way binding on the Internal
Revenue Service. It is intended only to reflect our best professional judgement
as to the matters set forth herein.

        We hereby consent to the filing of this opinion as an exhibit to the
Proxy Statement and to the use of our name under the heading "THE MERGER -
Certain Federal Income Tax Consequences of the Merger" in the Proxy Statement.
In giving such consent, we do not thereby concede that we are within the
category of persons whose consent is required under Section 7 of this Securities
Act of 1933, as amended, or the Rules and Regulations of the Securities and
Exchange Commission thereunder.

                                        Very truly yours,



                                        GODFREY & KAHN, S.C.


<PAGE>
 
                                                                    EXHIBIT 23.1
 
                   CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS
 
  As independent public accountants, we hereby consent to the incorporation by
reference in this Form S-4 Registration Statement to register common stock of
Marshall & Ilsley Corporation, of our report dated January 31, 1997, included
in the Marshall & Ilsley Corporation and Subsidiaries' Form 10-K for the year
ended December 31, 1996, and Form 10-K/A dated as of June 3, 1997, and to all
references to our Firm included in such Registration Statement.
 
                                          Arthur Andersen LLP
 
Milwaukee, Wisconsin
June 2, 1997

<PAGE>
 
                                                                   EXHIBIT 23.2
 
                       CONSENT OF KPMG PEAT MARWICK LLP
 
The Board of Directors
Security Capital Corporation:
 
  We consent to incorporation by reference in the Registration Statement on
Form S-4 of Marshall & Ilsley Corporation of our report dated July 15, 1996,
relating to the consolidated statements of financial condition of Security
Capital Corporation and subsidiaries as of June 30, 1996 and 1995, and the
related consolidated statements of income, changes in stockholders' equity and
cash flows for each of the years in the three-year period ended June 30, 1996,
which report appears in the June 30, 1996 annual report on Form 10-K of
Security Capital Corporation and to the reference to our firm under the
heading "Experts" in the Registration Statement.
 
                                          KPMG Peat Marwick LLP
 
Milwaukee, Wisconsin
May 30, 1997

<PAGE>
 
                                                                   EXHIBIT 23.4
 
                              [BAIRD LETTERHEAD]
 
  Robert W. Baird & Co. Incorporated ("Baird") hereby consents to the
inclusion in the Proxy Statement-Prospectus of Security Capital Corporation
and Marshall & Ilsley Corporation, filed as a part of this Registration
Statement on Form S-4 of Marshall & Ilsley Corporation, of its opinion dated
March 14, 1997, and to the references made to Baird in the "Summary" and
"Opinion of Financial Adviser to Security" sections of such Proxy Statement-
Prospectus. 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 or the rules and regulations of the Securities and
Exchange Commission promulgated thereunder.
 
                                          Robert W. Baird & Co. Incorporated
 
                                                 /s/ Robert W. Baird & Co.
                                                        Incorporated
                                          By: _________________________________
 
April 18, 1997

<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 8th day of April, 1997.
 
                                          /s/ Richard A. Abdoo
                                          -------------------------------------
                                          Richard A. Abdoo
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Oscar C. Boldt
                                          -------------------------------------
                                          Oscar C. Boldt
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ J.P. Bolduc
                                          -------------------------------------
                                          J.P. Bolduc
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Jon F. Chait
                                          -------------------------------------
                                          Jon F. Chait
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Glenn A. Francke
                                          _____________________________________
                                          Glenn A. Francke
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 27th day of March, 1997.
 
                                          /s/ G.H. Gunnlaugsson
                                          -------------------------------------
                                          G.H. Gunnlaugsson
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Burleigh E. Jacobs
                                          -------------------------------------
                                          Burleigh E. Jacobs
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 7th day of April, 1997.
 
                                          /s/ Jack F. Kellner
                                          -------------------------------------
                                          Jack F. Kellner
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 30th day of March, 1997.
 
                                          /s/ James F. Kress
                                          -------------------------------------
                                          James F. Kress
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ D.J. Kuester
                                          -------------------------------------
                                          D.J. Kuester
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Edward L. Meyer, Jr.
                                          -------------------------------------
                                          Edward L. Meyer, Jr.
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 2nd day of April, 1997.
 
                                          /s/ Don R. O'Hare
                                          -------------------------------------
                                          Don R. O'Hare
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 16th day of April, 1997.
 
                                          /s/ San W. Orr, Jr.
                                          -------------------------------------
                                          San W. Orr, Jr.
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Peter M. Platten, III
                                          -------------------------------------
                                          Peter M. Platten, III
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ Stuart W. Tisdale
                                          _____________________________________
                                          Stuart W. Tisdale
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 31st day of March, 1997.
 
                                          /s/ J.B. Wigdale
                                          -------------------------------------
                                          J.B. Wigdale
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 4th day of April, 1997.
 
                                          /s/ James O. Wright
                                          -------------------------------------
                                          James O. Wright
<PAGE>
 
                                                                     EXHIBIT 24
 
                         DIRECTOR'S POWER OF ATTORNEY
(FORM S-4 RELATING TO THE PROPOSED MERGER OF SECURITY CAPITAL CORPORATION WITH
                                   AND INTO
                        MARSHALL & ILSLEY CORPORATION)
 
  The undersigned director of Marshall & Ilsley Corporation designates each of
J.B. Wigdale and M.A. Hatfield, with the power of substitution, as his true
and lawful attorney-in-fact for the purpose of: (i) executing in his name and
on his behalf Marshall & Ilsley Corporation's Registration Statement on Form
S-4 relating to the proposed merger of Security Capital Corporation with and
into Marshall & Ilsley Corporation and any related amendments (including post-
effective amendments) and/or supplements to said Form S-4; (ii) generally
doing all things in his name and on his behalf in his capacity as a director
to enable Marshall & Ilsley Corporation to comply with the provisions of the
Securities Exchange Act of 1934, as amended, the Securities Act of 1933, as
amended, and all requirements of the Securities and Exchange Commission; and
(iii) ratifying and confirming his signature as it may be signed by the
attorney-in-fact to the Form S-4 and any related amendments (including post-
effective amendments) and/or supplements thereto.
 
Dated this 11th day of April, 1997.
 
                                          /s/ Gus A. Zuehlke
                                          -------------------------------------
                                          Gus A. Zuehlke

<PAGE>
 
                                                                   EXHIBIT 99.1
 
          SECURITY CAPITAL CORPORATION--SPECIAL MEETING--JULY 9, 1997
   This proxy appointment is solicited on behalf of the Board of Directors.
 
  The undersigned hereby acknowledges receipt of the Notice of Special Meeting
of Shareholders (the "Special Meeting") and the Proxy Statement-Prospectus
and, revoking any proxy heretofore given, hereby constitutes and appoints
Timothy C. Foote and Robert J. Koehler, directors of Security Capital
Corporation (the "Company"), or any successors in their respective positions,
to represent and to vote, as designated below, all the shares of common stock,
$1.00 par value per share ("Common Stock") of the Company held of record by
the undersigned on June 4, 1997, at the Special Meeting which will be held on
July 9, 1997, at 10:00 a.m., Milwaukee time, at The Grand Milwaukee Hotel,
Grand Ballroom East, 4747 South Howell Avenue, Milwaukee, Wisconsin or any
adjournments or postponements thereof as follows:
 
1. Proposal to approve and adopt an Agreement and Plan of Merger, dated as of
   March 14, 1997, that provides for, among other things, the merger of
   Security Capital Corporation with and into Marshall & Ilsley Corporation.
 
  [_] FOR                      [_] AGAINST                     [_] ABSTAIN
 
2. In their discretion, the Proxies are authorized to vote upon such other
   business as may properly come before the Special Meeting, or any
   adjournments or postponements thereof.
 
  THIS PROXY IS REVOCABLE AND WILL BE VOTED AS DIRECTED, BUT IF NO
INSTRUCTIONS ARE SPECIFIED, THIS PROXY WILL BE VOTED FOR EACH OF THE MATTERS
LISTED. If any other business is presented at the Special Meeting, this proxy
will be voted by the Board of Directors of the Company in their best judgment.
At the present time, the Board of Directors of the Company knows of no other
business to be presented at the Special Meeting.
 
  ----------------------------------      -------------------------------------
  Signature                               Signature
 
Dated:        , 1997                      IMPORTANT: Please sign your name
                                           exactly as it appears hereon. When
                                           signing as an attorney,
                                           administrator, agent, corporation,
                                           officer, executor, trustee,
                                           guardian or similar position,
                                           please add your full title to your
                                           signature. If shares of Common
                                           Stock are held jointly, each holder
                                           may sign but only one signature is
                                           required.
 
[ADDRESS IMPRINTED HERE]
 
                                          [_] PLEASE CHECK BOX IF YOU PLAN TO
                                           ATTEND THE MEETING IN PERSON
 
   IMPORTANT: PLEASE MARK, SIGN, DATE AND PROMPTLY RETURN THIS PROXY IN THE
                        ENCLOSED POSTAGE-PAID ENVELOPE.

<PAGE>
 
                                                                   EXHIBIT 99.2
 
                     RULE 438 CONSENT OF DIRECTOR DESIGNEE
 
                                                                   June 4, 1997
 
  The undersigned hereby consents, pursuant to Rule 438 under the Securities
Act of 1933, as amended, to the references to him as a future director of
Marshall & Ilsley Corporation in the Proxy Statement-Prospectus included in
this Registration Statement.
 
                                          Signed: /s/ Robert A. Schaefer 
                                                  ----------------------
                                                  Robert A. Schaefer 


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