SOUTHWEST GAS CORP
S-3/A, 1995-10-06
NATURAL GAS TRANSMISISON & DISTRIBUTION
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<PAGE>   1
 
   
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON OCTOBER 6, 1995
    
   
                                                       REGISTRATION NO. 33-62143
    
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
   
                                AMENDMENT NO. 1
    
   
                                       TO
    
 
                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
 
                           SOUTHWEST GAS CORPORATION
                            SOUTHWEST GAS CAPITAL I
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
<TABLE>
<S>                                                     <C>
                       CALIFORNIA                                              88-0085720
                        DELAWARE                                           TO BE APPLIED FOR
            (STATE OR OTHER JURISDICTION OF                                 (I.R.S. EMPLOYER
             INCORPORATION OR ORGANIZATION)                              IDENTIFICATION NUMBER)
</TABLE>
 
                            ------------------------
 
                           5241 SPRING MOUNTAIN ROAD
                                 P.O. BOX 98510
                          LAS VEGAS, NEVADA 89193-8510
                                 (702) 876-7237
(ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF EACH
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
                            ------------------------
 
                                GEORGE C. BIEHL
                 SENIOR VICE PRESIDENT/CHIEF FINANCIAL OFFICER
                           SOUTHWEST GAS CORPORATION
                           5241 SPRING MOUNTAIN ROAD
                                 P.O. BOX 98510
                          LAS VEGAS, NEVADA 89193-8510
                                 (702) 876-7237
 (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)
                            ------------------------
 
        APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
  From time to time after the effective date of this Registration Statement as
                        determined by market conditions.
 
    If the only securities being registered on this form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. / /
 
    If any of the securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box. /X/
 
    If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. / /
                                                            ---------------
 
    If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. / /
                           ---------------
 
    If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. / /
 
                        CALCULATION OF REGISTRATION FEE
 
<TABLE>
<S>                                                                   <C>                    <C>
- --------------------------------------------------------------------------------------------------------------------
- --------------------------------------------------------------------------------------------------------------------
                                                                         PROPOSED MAXIMUM
                        TITLE OF EACH CLASS OF                          AGGREGATE OFFERING          AMOUNT OF
                     SECURITIES TO BE REGISTERED                             PRICE(7)          REGISTRATION FEE(7)
- --------------------------------------------------------------------------------------------------------------------
Debt Securities.......................................................         (1)(2)                  NA
- --------------------------------------------------------------------------------------------------------------------
Preferred Stock ($50 par value).......................................         (1)(3)                  NA
- --------------------------------------------------------------------------------------------------------------------
Depositary Shares.....................................................        (1)(3)(4)                NA
- --------------------------------------------------------------------------------------------------------------------
Common Stock ($1 par value)...........................................         (1)(5)                  NA
- --------------------------------------------------------------------------------------------------------------------
Preferred Securities of Southwest Gas Capital I.......................         (1)(2)                  NA
- --------------------------------------------------------------------------------------------------------------------
Guarantee of Preferred Securities of Southwest Gas Capital I..........         (1)(6)                  NA
- --------------------------------------------------------------------------------------------------------------------
Total.................................................................      $270,400,000             $93,243
- --------------------------------------------------------------------------------------------------------------------
- --------------------------------------------------------------------------------------------------------------------
</TABLE>
 
    THE REGISTRANTS HEREBY AMEND 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>   2
 
(Footnotes from preceding page)
 
(1) In no event will the aggregate maximum offering price of all securities
    issued pursuant to this Registration Statement exceed $270,400,000 or, if
    any Debt Securities are issued with original issue discount, such greater
    amount as shall result in an aggregate offering price of $270,400,000. Any
    securities registered hereunder may be sold separately or as units with
    other securities registered hereunder.
 
(2) Subordinated Debt Securities may be issued and sold to Southwest Gas Capital
    I, in which event such Subordinated Debt Securities may later be distributed
    to the holders of Preferred Securities upon a dissolution of Southwest Gas
    Capital I and the distribution of the assets thereof.
 
(3) Shares of Preferred Stock and Depositary Shares may be issuable upon
    conversion of Debt Securities registered hereby.
 
(4) In the event Southwest Gas Corporation elects to offer to the public
    fractional interests in shares of the Preferred Stock registered hereunder,
    Depository Receipts will be distributed to those persons purchasing such
    fractional interests, and the shares of Preferred Stock will be issued to
    the Depositary under any such Deposit Agreement.
 
   
(5) Shares of Common Stock may be issuable in primary offerings and upon
    conversion of the Preferred Stock, Debt Securities or Preferred Securities
    registered hereby.
    
 
   
(6) Includes the rights of holders of the Preferred Securities under the
    Guarantee and certain back-up undertakings as described in the Registration
    Statement. Pursuant to Rule 457(n) under the Securities Act of 1933, no fee
    is payable with respect to the Guarantee and back-up undertakings.
    
 
(7) Calculated pursuant to Rule 457(o) of the rules and regulations under the
    Securities Act of 1933, as amended. Pursuant to Rule 429, $93,143 of the
    registration fee was previously paid in connection with Registration
    Statement No. 33-55621. The amount of the Securities being carried forward
    is $270,112,800.
 
     AS PERMITTED BY RULE 429, THE PROSPECTUS WITH RESPECT TO THIS REGISTRATION
STATEMENT ALSO RELATES TO SOUTHWEST GAS CORPORATION'S REGISTRATION STATEMENT ON
FORM S-3 (33-55621).
<PAGE>   3
 
     INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A
     REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE
     SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR
     MAY OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT
     BECOMES EFFECTIVE. THIS PROSPECTUS SHALL NOT CONSTITUTE AN OFFER TO SELL OR
     THE SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF THESE
     SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD BE
     UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS
     OF ANY SUCH STATE.
 
   
SUBJECT TO COMPLETION DATED OCTOBER 6, 1995
    
PROSPECTUS
                                  $270,400,000
 
                           SOUTHWEST GAS CORPORATION
            SENIOR DEBT SECURITIES AND SUBORDINATED DEBT SECURITIES
                                PREFERRED STOCK
                          DEPOSITARY PREFERRED SHARES
                                  COMMON STOCK
 
                            SOUTHWEST GAS CAPITAL I
                              PREFERRED SECURITIES
     GUARANTEED TO THE EXTENT SET FORTH HEREIN BY SOUTHWEST GAS CORPORATION
 
    Southwest Gas Corporation (the "Company") may offer from time to time, in
one or more series, its unsecured debt securities (the "Debt Securities"),
consisting of either unsecured Debt Securities which, if issued, will rank on a
parity with all other unsecured and unsubordinated indebtedness of the Company
(the "Senior Debt Securities") or unsecured Debt Securities which, if issued,
will be subordinate and junior in right of payment to certain other indebtedness
of the Company on terms to be determined at the time of the offering (the
"Subordinated Debt Securities"), shares of its Preferred Stock, $50 par value
(the "Preferred Stock") and shares of its Common Stock, $1 par value (the
"Common Stock"). Southwest Gas Capital I, a statutory business trust formed
under the laws of the State of Delaware (the "Trust"), may offer, from time to
time, preferred securities representing undivided beneficial interests in the
assets of the Trust (the "Preferred Securities"). The Debt Securities, the
Preferred Stock, the Common Stock and the Preferred Securities are collectively
referred to herein as the "Securities." Securities will have a maximum aggregate
offering price of $270,400,000 and will be offered on terms to be determined at
the time of offering.
 
    The payment of periodic cash distributions ("distributions") with respect to
the Preferred Securities out of moneys held by the Trust and payments on
liquidation, redemption or otherwise with respect to the Preferred Securities,
will be guaranteed by the Company to the extent described herein (the
"Guarantee"). See "Description of the Guarantee". The Company's obligations
under the Guarantee are subordinate and junior in right of payment to all other
liabilities of the Company and rank pari passu with the most senior preferred
stock, if any, issued from time to time by the Company. Subordinated Debt
Securities may be issued and sold by the Company to the Trust, or a trustee of
the Trust, in connection with the investment of the proceeds from the offering
of Preferred Securities and Common Securities (as defined herein) of the Trust.
The Subordinated Debt Securities purchased by the Trust may be subsequently
distributed pro rata to holders of Preferred Securities and Common Securities in
connection with the dissolution of the Trust upon the occurrence of certain
events as described in an accompanying Prospectus Supplement (as defined below).
 
    In the case of Debt Securities, the specific title, the aggregate principal
amount, the purchase price, the maturity, the rate (or method of calculation)
and time of payment of interest, if any, the right of the Company, if any, to
defer payment of interest on the Debt Securities and the maximum length of such
deferral period, any redemption or sinking fund provisions, any conversion
provisions, any subordination terms, any covenants and any other specific term
of the Debt Securities will be set forth in an accompanying supplement to this
Prospectus (each, a "Prospectus Supplement"). In the case of Preferred Stock,
the specific number of shares, designation, liquidation preference per share,
issuance price, dividend rate (or method of calculation), dividend payment
dates, any redemption or sinking fund provisions, any conversion rights and
other specific terms of the series of Preferred Stock will be set forth in the
accompanying Prospectus Supplement. In addition, the Prospectus Supplement will
describe whether interests in the Preferred Stock will be represented by
depositary shares (the "Depositary Shares") evidenced by depositary receipts
("Depositary Receipts"). In the case of Common Stock, the specific number of
shares, issuance price per share and the initial dividend rate of any Special
Common Stock (as defined herein), if Special Common Stock is to be issued, will
be set forth in the accompanying Prospectus Supplement. In the case of Preferred
Securities, the designation, number of securities, liquidation preference per
security, purchase price, distribution rate (or method of calculation thereof),
dates on which distributions shall be payable and dates from which distributions
shall accrue, any voting rights, terms for any conversion or exchange into other
securities, any redemption, exchange or sinking fund provisions, any other
rights, preferences, privileges, limitations or restrictions related to the
Preferred Securities and the terms upon which the proceeds of the sale of the
Preferred Securities shall be used to purchase Subordinated Debt Securities of
the Company will be set forth in the accompanying Prospectus Supplement. The
Prospectus Supplement will also disclose whether the Securities will be listed
on a national securities exchange and if they are not to be listed, the possible
effects thereof on their marketability. If so specified in the accompanying
Prospectus Supplement, Securities may be issued, in whole or in part, in
book-entry form.
 
    Securities may be sold directly, through agents from time to time, through
underwriters and/or dealers or through a combination of such methods. If any
agent of the Company or any underwriter is involved in the sale of the
Securities, the name of such agent or underwriter and any applicable commission
or discount will be set forth in the accompanying Prospectus Supplement. See
"Plan of Distribution."
 
    This Prospectus may not be used to consummate sales of Securities unless
accompanied by a Prospectus Supplement.
                            ------------------------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
    EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
       COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
          ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION
                     THE CONTRARY IS A CRIMINAL OFFENSE.
 
The date of this Prospectus is              , 1995
<PAGE>   4
 
                             AVAILABLE INFORMATION
 
     The Company is subject to the informational requirements of the Securities
Exchange Act of 1934 (the "Exchange Act") and, in accordance therewith, files
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 Room 1024 of the offices of the
Commission, Judiciary Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549, and
should be available for inspection and copying at the regional offices of the
Commission located at Seven World Trade Center 13th Floor, New York, New York
10048 and Suite 1400, Northwestern Atrium Center, 500 West Madison Street,
Chicago, Illinois 60661. Copies of such material can be obtained from the
principal offices of the Commission at Judiciary Plaza, 450 Fifth Street, N.W.,
Washington, D.C. 20549 at prescribed rates. Reports, proxy materials and other
information concerning the Company may also be inspected at the offices of the
New York Stock Exchange, 20 Broad Street, New York, New York 10005 and at the
offices of the Pacific Stock Exchange, 301 Pine Street, San Francisco,
California 94104.
 
   
     No separate financial statements of the Trust have been included herein.
The Company does not consider that such financial statements would be material
to holders of the Preferred Securities because (i) all of the voting securities
of the Trust will be owned directly or indirectly, by the Company, a reporting
company under the Exchange Act, (ii) the Trust has no independent operations but
exists for the sole purpose of issuing securities representing undivided
beneficial interests in the assets of the Trust and investing the proceeds
thereof in Subordinated Debt Securities issued by the Company, and (iii) the
obligations of the Trust under the Trust Securities (as defined herein) will be
fully and unconditionally guaranteed by the Company to the extent that the
Company has made a payment of interest or principal on the Subordinated Debt
Securities. See "Particular Terms of the Subordinated Debt Securities Issued in
Connection with Preferred Securities" and "Description of the Guarantee." The
financial information for the Trust will be included in the consolidated
financial statements of the Company.
    
 
     This Prospectus does not contain all the information set forth in the
Registration Statement and exhibits thereto which the Company and the Trust have
filed with the Commission under the Securities Act of 1933, and reference is
hereby made to such Registration Statement, including the exhibits thereto.
                            ------------------------
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
     There are incorporated herein by reference the following documents of the
Company filed with the Commission: (1) Annual Report on Form 10-K for the fiscal
year ended December 31, 1994; (2) Quarterly Reports on Form 10-Q for the
quarters ended March 31, 1995 and June 30, 1995, (3) Current Reports on Form 8-K
dated April 17, 1995 and May 3, 1995; and (4) all documents filed by the Company
pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to
the date of this Prospectus and prior to the termination of the offering of the
Securities.
 
     Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this Prospectus to the extent that a statement contained herein,
in a Prospectus Supplement or in any subsequently filed document which is
incorporated by reference herein modifies or supersedes such statements. Any
such statement so modified or superseded shall not be deemed, except as so
modified or superseded, to constitute a part of this Prospectus.
 
     The information relating to the Company contained in this Prospectus
summarizes, is based upon, or refers to, information and financial statements
contained in one or more of the documents incorporated by reference herein;
accordingly, such information contained herein is qualified in its entirety by
reference to such incorporated documents and should be read in conjunction
therewith.
 
     The Company will provide without charge to each person, including any
beneficial holder, to whom a copy of this Prospectus is delivered, upon the
written or oral request of any such person, a copy of any or all the foregoing
documents incorporated by reference herein, including exhibits specifically
incorporated by reference in such documents but excluding all other exhibits to
such documents. Requests should be directed to George C. Biehl, Senior Vice
President and Chief Financial Officer, Southwest Gas Corporation,
 
                                        2
<PAGE>   5
 
5241 Spring Mountain Road, P.O. Box 98510, Las Vegas, Nevada 89193-8510,
telephone number (702) 876-7237.
 
                                  THE COMPANY
 
     The Company, a California corporation, is comprised of two operating
segments: natural gas operations and financial services. The financial services
segment consists of PriMerit Bank, a Federal Savings Bank (the "Bank"), a wholly
owned subsidiary, which operates principally in the thrift industry.
 
     The natural gas operations segment is engaged in the business of
purchasing, transporting, and distributing natural gas in portions of Arizona,
Nevada and California. Its several service areas are geographically as well as
economically diverse. The Company is the largest distributor in Arizona,
distributing and transporting gas in most of southern, central and northwestern
Arizona. The Company is also the largest distributor and transporter of natural
gas in Nevada. The Company also distributes and transports gas in portions of
California, including the Lake Tahoe area and the high desert and mountain areas
in San Bernardino County.
 
     The Company is subject to regulation by the Arizona Corporation Commission,
the Public Service Commission of Nevada (the "PSCN") and the California Public
Utilities Commission (the "CPUC"). The CPUC regulates the issuance of all
securities by the Company, with the exception of short-term borrowings. Certain
of the Company's accounting practices, transmission facilities and rates are
subject to regulation by the Federal Energy Regulatory Commission.
 
     The Bank is a federally chartered stock savings bank conducting business
through branch offices in Nevada. The Bank's deposit accounts are insured to the
maximum extent permitted by law by the Federal Deposit Insurance Corporation
(the "FDIC") through the Savings Association Insurance Fund. The Bank is
regulated by the Office of Thrift Supervision (the "OTS") and the FDIC and is a
member of the Federal Home Loan Bank system.
 
     The Bank's principal business is to attract deposits from the general
public and to make loans secured by real estate and other collateral that enable
borrowers to purchase, refinance, construct or improve such property. Revenues
are derived from interest on real estate loans and debt securities and, to a
lesser extent, from interest on nonmortgage loans, gains on sales of loans and
debt securities, and fees received in connection with loans and deposits. The
Bank's major expense is the interest it pays on savings deposits and borrowings.
 
     The executive offices of the Company are located at 5241 Spring Mountain
Road, P.O. Box 98510, Las Vegas, Nevada 89193-8510, telephone number (702)
876-7237.
 
                                   THE TRUST
 
     The Trust is a statutory business trust formed under Delaware law pursuant
to (i) a declaration of trust (a "Declaration") executed by the Company, as
sponsor for the Trust (the "Sponsor"), and Trustees (as defined herein) of the
Trust and (ii) the filing of a certificate of trust with the Secretary of State
of the State of Delaware on August 17, 1995. The Trust exists for the exclusive
purposes of (i) issuing the Preferred Securities and common securities
representing undivided beneficial interests in the assets of the Trust (the
"Common Securities" and, together with the Preferred Securities, the "Trust
Securities"), (ii) investing the gross proceeds from the sale of the Trust
Securities in the Subordinated Debt Securities and (iii) engaging in only those
other activities necessary or incidental thereto. All of the Common Securities
will be directly or indirectly owned by the Company. The Common Securities will
rank pari passu, and payments will be made thereon pro rata, with the Preferred
Securities, except that, upon an event of default under the Declaration, the
rights of the holders of the Common Securities to payment in respect of
distributions and payments upon liquidation, redemption and otherwise will be
subordinated to the rights of the holders of the Preferred Securities. The
Company will directly or indirectly acquire Common Securities in an aggregate
liquidation amount equal to 3% of the total capital of the Trust. The Trust has
a term of approximately 55 years but may terminate earlier, as provided in the
Declaration.
 
                                        3
<PAGE>   6
 
     The Trust's business and affairs will be conducted by the trustees (the
"Trustees") appointed by the Company as the direct holder of all the Common
Securities. The holder of the Common Securities will be entitled to appoint,
remove or replace any of, or increase or reduce the number of, the Trustees of
the Trust; provided that the number of Trustees may not be reduced to less than
three. The duties and obligations of the Trustees will be governed by the
Declaration. A majority of the Trustees of the Trust will be persons who are
employees or officers of or who are affiliated with the Company (the "Regular
Trustees"). One Trustee of the Trust will be a financial institution that is not
affiliated with the Company, has a specified minimum amount of aggregate
capital, surplus, and undivided profits of not less than $50,000,000 and will
have a principal place of business or reside in the State of Delaware (the
"Delaware Trustee"). The Delaware Trustee will not be a trustee for purposes of
the Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"), and
will not perform the functions of a trustee under such Act. Another financial
institution that is not affiliated with the Company and has a specified minimum
amount of aggregate capital and surplus and undivided profits of not less than
$50,000,000 shall act as property trustee and as indenture trustee and trustee
under the Guarantee, in each case, for the purposes of the Trust Indenture Act
(the "Property Trustee"). The Company will pay all debts and obligations of the
Trust (other than with respect to the Trust Securities) and all fees and
expenses related to the Trust and the offering of the Trust Securities, the
payment of which will be guaranteed by the Company.
 
     The Delaware Trustee for the Trust will be Wilmington Trust Company, 1100
N. Market Street, Wilmington, Delaware 19890. The Property Trustee, indenture
trustee and trustee under the Guarantee will be Harris Trust and Savings Bank,
430 Park Avenue, 14th Floor, New York, New York 10022. The address for the Trust
is c/o Southwest Gas Corporation, the sponsor of the Trust, at the Company's
corporate headquarters located at 5241 Spring Mountain Road, Las Vegas, Nevada
89102, telephone (702) 876-7237.
 
     Harris Trust and Savings Bank and its affiliates may from time to time
maintain lines of credit, act as trustee for senior debt and otherwise have
customary banking relationships with the Company. Neither the Declaration nor
the Indenture for the Subordinated Debt Securities precludes Harris Trust and
Savings Bank or any of its affiliates from enforcing its rights or the rights of
any holders of senior debt for which it acts as trustee as creditors of the
Company unless there is an event of default under the Declaration or the
Indenture for the Subordinated Debt Securities.
 
                                USE OF PROCEEDS
 
     The Trust will use all proceeds received from the sale of the Preferred
Securities to purchase Subordinated Debt Securities from the Company. Except as
otherwise provided in the Prospectus Supplement, the Company intends to use the
proceeds of the sale of the Subordinated Debt Securities to the Trust and the
net proceeds from the sale of other Securities offered hereby to retire
indebtedness and for general corporate purposes, including the acquisition of
property for the construction, completion, extension or improvement of the
Company's pipeline systems and facilities located in and around the communities
it serves.
 
                                        4
<PAGE>   7
 
                      RATIOS OF EARNINGS TO FIXED CHARGES
 
     The following table sets forth the ratios of earnings to fixed charges for
(a) the natural gas operations segment of the Company and (b) the consolidated
gas and financial services operations of the Company (i) without deposit
interest included as a fixed charge and (ii) with deposit interest included as a
fixed charge.
 
<TABLE>
<CAPTION>
                                                                         FOR THE YEARS ENDED
                                                               ----------------------------------------
                                            FOR THE TWELVE
                                             MONTHS ENDED                    DECEMBER 31,
                                               JUNE 30,        ----------------------------------------
                                                 1995          1994     1993     1992     1991     1990
                                            --------------     ----     ----     ----     ----     ----
<S>                                         <C>                <C>      <C>      <C>      <C>      <C>
Ratios of earnings to fixed charges(1):
  Company (natural gas operations
     segment).............................       1.27          1.48     1.25     1.86     1.48     1.84
  Consolidated
     Without deposit interest.............       1.36          1.55     1.32     1.42      (2)     1.45
     With deposit interest................       1.23          1.36     1.18     1.20      (2)     1.24
</TABLE>
 
- ---------------
 
(1) For purposes of computing the ratios of earnings to fixed charges, earnings
    are defined as the sum of pretax income plus fixed charges. Fixed charges
    consist of all interest expense including capitalized interest, one-third of
    rent expense (which approximates the interest component of such expense) and
    amortized debt costs.
 
(2) For the year ended December 31, 1991, consolidated earnings were
    insufficient to cover fixed charges, excluding and including deposit
    interest, by $13.5 million. This was primarily due to the recording of
    additional valuation reserves during 1991 by the Bank.
 
     The following table sets forth the ratios of earnings to combined fixed
charges and preferred and preference stock dividends for (a) the natural gas
segment of the Company and (b) the consolidated gas and financial services
operations of the Company (i) without deposit interest included as a fixed
charge and (ii) with deposit interest included as a fixed charge.
 
<TABLE>
<CAPTION>
                                                                         FOR THE YEARS ENDED
                                                               ----------------------------------------
                                            FOR THE TWELVE
                                             MONTHS ENDED                    DECEMBER 31,
                                               JUNE 30,        ----------------------------------------
                                                 1995          1994     1993     1992     1991     1990
                                            --------------     ----     ----     ----     ----     ----
<S>                                         <C>                <C>      <C>      <C>      <C>      <C>
Ratios of earnings to combined fixed
  charges and preferred and preference
  stock dividends(1)
  Company (natural gas operations
     segment).............................       1.26          1.46     1.23     1.81     1.42     1.75
  Consolidated
     Without deposit interest.............       1.35          1.54     1.30     1.39      (2)     1.43
     With deposit interest................       1.22          1.35     1.17     1.18      (2)     1.22
</TABLE>
 
- ---------------
 
(1) See Note 1 above. Preferred and preference stock dividends have been
    adjusted to represent the pretax earnings necessary to cover such dividend
    requirements.
 
(2) For the year ended December 31, 1991, consolidated earnings were
    insufficient to cover combined fixed charges and preferred and preference
    stock dividends by $14.8 million. This was primarily due to the recording of
    additional valuation reserves during 1991 by the Bank.
 
                         DESCRIPTION OF DEBT SECURITIES
 
     Debt Securities may be issued from time to time in series, either as Senior
Debt Securities or Subordinated Debt Securities, each under an indenture (each,
an "Indenture") between the Company and a bank or trust company selected to act
as trustee as specified in the Prospectus Supplement relating thereto (the
"Trustee"). Each Indenture will be filed as an exhibit to or incorporated by
reference in the Registration Statement of which this Prospectus is a part. As
used under this caption, unless the context otherwise requires, Offered Debt
Securities shall mean the Debt Securities offered by this Prospectus and the
accompanying Prospectus Supplement. The statements under this caption are brief
summaries of certain provisions contained
 
                                        5
<PAGE>   8
 
in the Indenture, do not purport to be complete and are qualified in their
entirety by reference to the applicable Indentures, including the definition
therein of certain terms, a copy of each of which is included or incorporated by
reference as an exhibit to the Registration Statement of which this Prospectus
is a part. Capitalized terms used herein and not defined shall have the meanings
assigned to them in the applicable Indenture. The following sets forth certain
general terms and provisions of the Debt Securities. Additional terms of
Subordinated Debt Securities issued in connection with the Preferred Securities
are set forth under the caption "Particular Terms of Subordinated Debt
Securities Issued in Connection with Preferred Securities." Further terms of the
Offered Debt Securities will be set forth in the Prospectus Supplement.
 
GENERAL
 
     Each Indenture provides for the issuance of Debt Securities in series, and
does not limit the principal amount of Debt Securities which may be issued
thereunder.
 
     The applicable Prospectus Supplement or Prospectus Supplements will
describe the following terms of the series of Offered Debt Securities in respect
of which this Prospectus is being delivered: (a) the title of the Offered Debt
Securities; (b) whether any of the Offered Debt Securities are to be issuable in
bearer form or permanent global form and, if so, the terms and conditions, if
any, upon which interests in such Offered Debt Securities in such bearer form or
global form may be exchanged, in whole or in part, for the Offered Debt
Securities represented thereby; (c) the person to whom any interest on any
Offered Debt Security of the series shall be payable if other than the person in
whose name the Offered Debt Security is registered on the Regular Record Date;
(d) the date or dates on which the Offered Debt Securities will mature; (e) the
rate or rates at which the Offered Debt Securities will bear interest, if any;
(f) the date or dates from which any such interest will accrue, the Interest
Payment Dates on which any such interest on the Offered Debt Securities will be
payable and the Regular Record Date for any interest payable on any Interest
Payment Date; (g) each office or agency where the principal of, premium (if any)
and interest on the Offered Debt Securities will be payable; (h) the period or
periods within which, the events upon the occurrence of which, and the price or
prices at which, the Offered Debt Securities may, pursuant to any optional or
mandatory provisions, be redeemed or purchased, in whole or in part, by the
Company and any terms and conditions relevant thereto; (i) the obligation of the
Company, if any, to redeem or repurchase the Offered Debt Securities at the
option of the Holders; (j) the denominations in which any Offered Debt
Securities will be issuable, if other than denominations of $1,000 and any
integral multiple thereof with respect to Debt Securities, other than
Subordinated Debt Securities issued in connection with Preferred Securities, or
denominations of $25 and any integral multiple thereof with respect to
Subordinated Debt Securities issued in connection with Preferred Securities; (k)
the currency or currencies, including composite currencies, of payment of
principal of and any premium and interest on the Offered Debt Securities, if
other than U. S. Dollars; (l) any index or formula used to determine the amount
of payments of principal of and any premium and interest on the Offered Debt
Securities; (m) if other than the principal amount thereof, the portion of the
principal amount of the Offered Debt Securities of the series which will be
payable upon declaration of the acceleration of the Maturity thereof; (n) any
provisions relating to the conversion or exchange of the Offered Debt Securities
into Common Stock, Preferred Stock or into Debt Securities of another series;
(o) any Events of Default with respect to the Offered Debt Securities, if not
otherwise set forth under "Events of Default"; (p) any material
covenants with respect to the Offered Debt Securities; (q) the applicability of
the provisions described under "Defeasance"; and (r) any other terms of the
Offered Debt Securities not inconsistent with the provisions of the applicable
Indenture. The applicable Prospectus Supplement will also describe the following
terms of the series of Subordinated Debt Securities offered hereby in respect of
which this Prospectus is being delivered: (a) the rights, if any, to defer
payments of interest on the Subordinated Debt Securities by extending the
interest payment period, and the duration of such extensions, and (b) the
subordination terms of the Subordinated Debt Securities of such series.
 
     Debt Securities may be issued at a discount from their principal amount.
Federal income tax considerations and other special considerations applicable to
any such Original Issue Discount Securities will be described in the applicable
Prospectus Supplement.
 
                                        6
<PAGE>   9
 
     Debt Securities may be issued in bearer form, with or without coupons.
Federal income tax considerations and other special considerations applicable to
bearer securities will be described in the applicable Prospectus Supplement.
 
CONVERSION RIGHTS
 
     The terms, if any, on which Debt Securities of a series may be exchanged
for or converted into shares of Common Stock, Preferred Stock or Debt Securities
of another series will be set forth in the Prospectus Supplement relating
thereto.
 
EXCHANGE, REGISTRATION, TRANSFER AND PAYMENT
 
     Unless otherwise specified in the applicable Prospectus Supplement, payment
of principal, premium, if any, and interest on the Debt Securities will be
payable, and the exchange of and the transfer of Debt Securities will be
registerable, at the office or agency of the Company maintained for such purpose
in New York, New York and at any other office or agency maintained for such
purpose. Unless otherwise indicated in the applicable Prospectus Supplement,
Debt Securities, other than Subordinated Debt Securities issued in connection
with Preferred Securities, will be issued in denominations of $1,000 or integral
multiples thereof. Subordinated Debt Securities issued in connection with
Preferred Securities will be issued in denominations of $25 or integral
multiples thereof. No service charge will be made for any registration of
transfer or exchange of the Debt Securities, but the Company may require payment
of a sum sufficient to cover any tax or other governmental charge imposed in
connection therewith.
 
     All moneys paid by the Company to a Paying Agent for the payment of
principal of and any premium or interest on any Debt Security which remain
unclaimed for two years after such principal, premium or interest has become due
and payable may be repaid to the Company and thereafter the Holder of such Debt
Security may look only to the Company for payment thereof.
 
BOOK-ENTRY DEBT SECURITIES
 
     The Debt Securities of a series may be issued in the form of one or more
Global Securities that will be deposited with a Debt Depositary or its nominee
identified in the applicable Prospectus Supplement. In such a case, one or more
Global Securities will be issued in a denomination or aggregate denominations
equal to the portion of the aggregate principal amount of Outstanding Debt
Securities of the series to be represented by such Global Security or
Securities. Each Global Security will be deposited with such Debt Depositary or
nominee or a custodian therefor and will bear a legend regarding the
restrictions on exchanges and registration of transfer thereof referred to below
and any such other matters as may be provided for pursuant to the applicable
Indenture.
 
     Notwithstanding any provision of the applicable Indenture or any Debt
Security described herein, no Global Security may be transferred to, or
registered or exchanged for Debt Securities registered in the name of, any
Person other than the Debt Depositary for such Global Security or any nominee of
such Debt Depositary, and no such transfer may be registered, unless (a) the
Debt Depositary has notified the Company that it is unwilling or unable to
continue as Debt Depositary for such Global Security or has ceased to be
qualified to act as such as required by the Indenture, (b) the Company executes
and delivers to the Trustee a Company Order that such Global Security shall be
so transferable, registrable and exchangeable, and such transfers shall be
registrable, or (c) there shall exist such circumstances, if any, as may be
described in the applicable Prospectus Supplement. All Debt Securities issued in
exchange for a Global Security or any portion thereof will be registered in such
names as the Debt Depositary may direct.
 
     The specific terms of the depositary arrangement with respect to any
portion of a series of Debt Securities to be represented by a Global Security
will be described in the applicable Prospectus Supplement. The Company expects
that the following provisions will apply to depositary arrangements.
 
     Unless otherwise specified in the applicable Prospectus Supplement, Debt
Securities which are to be represented by a Global Security to be deposited with
or on behalf of a Debt Depositary will be represented by
 
                                        7
<PAGE>   10
 
a Global Security registered in the name of such Debt Depositary or its nominee.
Upon the issuance of such Global Security, and the deposit of such Global
Security with or on behalf of the Debt Depositary for such Global Security, the
Debt Depositary will credit, on its book-entry registration and transfer system,
the respective principal amounts of the Debt Securities represented by such
Global Security to the accounts of institutions that have accounts with such
Debt Depositary or its nominee ("participants"). The accounts to be credited
will be designated by the underwriters or agents of such Debt Securities or by
the Company, if such Debt Securities are offered and sold directly by the
Company. Ownership of beneficial interests in such Global Security will be
limited to participants or Persons that may hold interests through participants.
Ownership of beneficial interests by participants in such Global Security will
be shown on, and the transfer of that ownership interest will be effected only
through, records maintained by the Debt Depositary or its nominee for such
Global Security. Ownership of beneficial interests in such Global Security by
Persons that hold through participants will be shown on, and the transfer of
that ownership interest within such participant will be effected only through,
records maintained by such participant. The laws of some jurisdictions require
that certain purchasers of securities take physical delivery of such securities
in certificated form. The foregoing limitations and such laws may impair the
ability to transfer beneficial interests in such Global Securities.
 
     So long as the Debt Depositary for a Global Security, or its nominee, is
the registered owner of such Global Security, such Depositary or such nominee,
as the case may be, will be considered the sole owner or Holder of the Debt
Securities represented by such Global Security for all purposes under the
applicable Indenture. Unless otherwise specified in the applicable Prospectus
Supplement, owners of beneficial interests in such Global Security will not be
entitled to have Debt Securities of the series represented by such Global
Security registered in their names, will not receive or be entitled to receive
physical delivery of Debt Securities of such series in certified form and will
not be considered the Holders thereof for any purposes under the applicable
Indenture. Accordingly, each Person owning a beneficial interest in such Global
Security must rely on the procedures of the Debt Depositary and, if such Person
is not a participant, on the procedures of the participant through which such
Person owns its interest, to exercise any rights of a Holder under the
applicable Indenture. The Company understands that under existing industry
practices, if the Company requests any action of Holders or an owner of a
beneficial interest in such Global Security desires to give any notice or take
any action a Holder is entitled to give or take under the applicable Indenture,
the Debt Depositary would authorize the participants to give such notice or take
such action, and participants would authorize beneficial owners owning through
such participants to give such notice or take such action or would otherwise act
upon the instructions of beneficial owners owning through them.
 
     Notwithstanding any other provisions to the contrary in the applicable
Indenture, the rights of the beneficial owners of the Debt Securities to receive
payment of the principal and premium, if any, of and interest on such Debt
Securities, on or after the respective due dates expressed in such Debt
Securities, or to institute suit for the enforcement of any such payment on or
after such respective dates, shall not be impaired or affected without the
consent of the beneficial owners.
 
     Principal of and any premium and interest on a Global Security will be
payable in the manner described in the applicable Prospectus Supplement.
 
CONSOLIDATION, MERGER AND SALE OF ASSETS
 
     The Company, without the consent of any Holders of Outstanding Debt
Securities, may consolidate with or merge into, or transfer or lease its assets
substantially as an entirety to, any Person, and any other Person may
consolidate with or merge into, or transfer or lease its assets substantially as
an entirety to, the Company, provided (a) that the Person (if other than the
Company) formed by such consolidation or into which the Company is merged or
which acquires or leases the assets of the Company substantially as an entirety
is a Person organized and existing under the laws of any United States
jurisdiction and assumes the Company's obligations on the Debt Securities and
under the Indentures, (b) that after giving effect to such transaction no Event
of Default, and no event which, after notice or lapse of time or both, would
become an Event of Default, shall have happened and be continuing, and (c) that
certain other conditions are met.
 
                                        8
<PAGE>   11
 
COVENANTS OF THE COMPANY
 
     The applicable Prospectus Supplement will describe any material covenants
in respect of a series of Offered Debt Securities. Other than the covenants of
the Company included in the Indentures as described above or as described in the
applicable Prospectus Supplement, there are no covenants or provisions in the
Offered Debt Securities or the Indentures that limit or restrict the Company's
business or operations, the pledging of the Company's assets or the incurrence
of indebtedness by the Company or that may afford Holders protection in the
event of a highly leveraged transaction or leveraged buyout involving the
Company.
 
EVENTS OF DEFAULT
 
     Unless otherwise specified in the applicable Prospectus Supplement, the
following are Events of Default under the Indentures with respect to Debt
Securities of any series: (a) failure to pay principal of or premium, if any, on
any Debt Security of that series when due; provided, however, that a valid
extension of the maturity of Subordinated Debt Securities shall not constitute a
default for this purpose; (b) failure to pay any interest on any Debt Security
of that series when due, continued for 30 days; provided, however, that a valid
extension of the interest payment provided by the Company for the Subordinated
Debt Securities shall not constitute a default in the payment of interest for
this purpose, and provided further that, if Subordinated Debt Securities are
issued to the Trust or a Trustee of the Trust in connection with the issuance of
Trust Securities by the Trust, such 30-day period will be replaced by a ten day
period; (c) failure to make any sinking fund payment, when due, in respect of
any Debt Security of that series; (d) failure to perform any other covenant of
the Company in the Indenture (other than a covenant included in the Indenture
solely for the benefit of a series of Debt Securities other than that series),
continued for 60 days after written notice by the Trustee or Holders of at least
25% in principal amount of the Outstanding Debt Securities of that series as
provided in the Indenture; (e) a default under any evidence of indebtedness for
money borrowed by the Company (including a default with respect to Debt
Securities of any other series) in an individual principal amount outstanding of
at least $15,000,000 or under any instrument under which there may be issued or
by which there may be secured or evidenced any indebtedness for money borrowed
by the Company (including the Indentures) in an individual principal amount
outstanding of at least $15,000,000, whether such indebtedness exists as of the
date of the applicable Indenture or is thereafter created, which default results
in the acceleration of such indebtedness without such indebtedness having been
discharged, or such acceleration having been rescinded or annulled, within 10
Business Days after written notice to the Company by the Trustee or by the
Holders of at least 25% in principal amount of the Outstanding Debt Securities
of such series as provided in the Indenture; (f) certain events of bankruptcy,
insolvency or reorganization of the Company; (g) the voluntary or involuntary
dissolution of the Trust pursuant to which (or of a Trustee of the Trust to
which) Subordinated Debt Securities were issued in connection with the issuance
of Trust Securities by the Trust, except in connection with the distribution of
Subordinated Debt Securities to the holders of Trust Securities in liquidation
of the Trust, the redemption of all of the Trust Securities, or certain mergers,
consolidations or amalgamations, each as permitted by the Declaration; and (h)
any other Event of Default provided with respect to Debt Securities of that
series. If an Event of Default with respect to Outstanding Debt Securities of
any series shall occur and be continuing, either the Trustee or the Holders of
at least 25% in principal amount of the Outstanding Debt Securities of that
series by notice as provided in the applicable Indenture may declare the
principal amount (or, if the Debt Securities of that series are Original Issue
Discount Securities, such portion of the principal amount as may be specified in
the terms of that series) of all Debt Securities of that series to be due and
payable immediately. However, at any time after a declaration of acceleration
with respect to Debt Securities of any series has been made, but before a
judgment or decree based on such acceleration has been obtained, the Holders of
a majority in principal amount of the Outstanding Debt Securities of that series
may, under certain circumstances, rescind and annul such acceleration. For
information as to waiver of defaults, see "Modification and Waiver" below.
 
     Each Indenture provides that, subject to the duty of the Trustee during an
Event of Default to act with the required standard of care, the Trustee will be
under no obligation to exercise any of its rights or powers under the Indenture
at the request or direction of any of the Holders, unless such Holders shall
have offered to the Trustee reasonable security or indemnity. Subject to certain
provisions, including those requiring security
 
                                        9
<PAGE>   12
 
or indemnification of the Trustee, the Holders of a majority in principal amount
of the Outstanding Debt Securities of any series will have the right to direct
the time, method and place of conducting any proceeding for any remedy available
to the Trustee, or exercising any trust or power conferred on the Trustee, with
respect to the Debt Securities of that series.
 
     The Company will be required to furnish to the Trustee under each Indenture
annually a statement as to the performance by the Company of its obligations
under the Indenture and as to any default in such performance.
 
MODIFICATION AND WAIVER
 
     Modifications and amendments of the Indenture may be made by the Company
and the Trustee with the consent of the Holders of not less than a majority in
principal amount of the Outstanding Debt Securities of each series affected
thereby; provided, however, that no such modification or amendment may, without
the consent of the Holder of each Outstanding Debt Security affected thereby;
(a) change the Stated Maturity of the principal of, or any installment of
principal of, or interest on, any Debt Security; (b) reduce the principal amount
of, the rate of interest on, or the premium, if any, payable upon the redemption
of, any Debt Security; (c) reduce the amount of principal of an Original Issue
Discount Security payable upon acceleration of the Maturity thereof; (d) change
the currency of payment of principal of, or premium, if any, or interest on any
Debt Security; (e) impair the right to institute suit for the enforcement of any
payment on or with respect to any Debt Security on or after the Stated Maturity
or Redemption Date thereof; or (f) reduce the percentage in principal amount of
Outstanding Debt Securities of any series, the consent of the Holders of which
is required for modification or amendment of the applicable Indenture or for
waiver of compliance with certain provisions of the applicable Indenture or for
waiver of certain defaults.
 
   
     The Holders of at least a majority in principal amount of the Outstanding
Debt Securities of any series may on behalf of the Holders of all Debt
Securities of that series waive, insofar as that series is concerned, compliance
by the Company with certain covenants of the Indenture. The applicable
Prospectus Supplement will describe the terms of any such covenants. The Holders
of not less than a majority in principal amount of the Outstanding Debt
Securities of any series may, on behalf of the Holders of all Debt Securities of
that series, waive any past default under the applicable Indenture with respect
to that series, except a default in the payment of the principal of, or premium,
if any, or interest on, any Debt Security of that series or in respect of a
provision which under such Indenture cannot be modified or amended without the
consent of the Holder of each Outstanding Debt Security of that series affected.
    
 
DEFEASANCE
 
     Unless otherwise specified in the applicable Prospectus Supplement with
respect to the Debt Securities of a series, other than Subordinated Debt
Securities issued in connection with Preferred Securities, the Company, at its
option, (i) will be discharged from any and all obligations in respect of the
Debt Securities of such series (except for certain obligations to register the
transfer or exchange of Debt Securities of such series, to replace destroyed,
stolen, lost or mutilated Debt Securities of such series, and to maintain Paying
Agents and hold moneys for payment in trust) or (ii) need not comply with
certain covenants specified in the applicable Prospectus Supplement with respect
to the Debt Securities of that series, and the occurrence of an event described
in clause (d) under "Events of Default" above with respect to any defeased
covenant and clauses (e) and (g) of the "Events of Default" above shall no
longer be an Event of Default if, in either case, the Company deposits with the
Trustee, in trust, money or U.S. Government Obligations that through the payment
of interest thereon and principal thereof in accordance with their terms will
provide money in an amount sufficient to pay all the principal of (and premium,
if any) and any interest on the Debt Securities of such series on the dates such
payments are due (which may include one or more redemption dates designated by
the Company) in accordance with the terms of such Debt Securities. Such a trust
may only be established if, among other things, (a) no Event of Default or event
which with the giving of notice or lapse of time, or both, would become an Event
of Default under the applicable Indenture shall have occurred and be continuing
on the date of such deposit, (b) no Event of Default described under clause (f)
under "Events of Default" above or event which with the giving of notice or
lapse of time, or both, would become an Event of Default described under such
clause (f) shall have occurred and be continuing at any time during the period
ending on the 91st day following such date of deposit, and (c) the Company shall
have delivered an Opinion of Counsel
 
                                       10
<PAGE>   13
 
to the effect that the Holders of the Debt Securities will not recognize gain or
loss for Federal income tax purposes as a result of such deposit or defeasance
and will be subject to Federal income tax in the same manner as if such
defeasance had not occurred. In the event the Company omits to comply with its
remaining obligations under the applicable Indenture after a defeasance of the
Indenture with respect to the Debt Securities of any series as described under
clause (ii) above and the Debt Securities of such series are declared due and
payable because of the occurrence of any undefeased Event of Default, the amount
of money and U.S. Government Obligations on deposit with the Trustee may be
insufficient to pay amounts due on the Debt Securities of such series at the
time of the acceleration resulting from such Event of Default. However, the
Company will remain liable in respect of such payments.
 
GOVERNING LAW
 
     Each Indenture and the Debt Securities will be governed by, and construed
in accordance with, the laws of the State of New York.
 
REGARDING THE TRUSTEE
 
     Each Indenture contains certain limitations on the right of the Trustee,
should it become a creditor of the Company, to obtain payment of claims in
certain cases, or to realize for its own account on certain property received in
respect of any such claim as security or otherwise. The Trustee will be
permitted to engage in certain other transactions; however, if it acquires any
conflicting interest and there is a default under the Debt Securities, it must
eliminate such conflict or resign.
 
                PARTICULAR TERMS OF SUBORDINATED DEBT SECURITIES
                 ISSUED IN CONNECTION WITH PREFERRED SECURITIES
 
     The statements under this caption are brief summaries of certain provisions
of the Subordinated Debt Securities Indenture applicable to Subordinated Debt
Securities issued in connection with Preferred Securities, do not purport to be
complete and are qualified in their entirety by reference to the Subordinated
Debt Securities Indenture.
 
     In the event Subordinated Debt Securities are issued to the Trust or a
Trustee of the Trust in connection with the issuance of Trust Securities by the
Trust, such Subordinated Debt Securities subsequently may be distributed pro
rata to the holders of the Trust Securities in connection with the dissolution
of the Trust upon the occurrence of certain events described in the applicable
Prospectus Supplement relating to the Trust Securities. Only one series of
Subordinated Debt Securities will be issued to the Trust or a Trustee of the
Trust in connection with the issuance of Trust Securities by the Trust.
 
     If Subordinated Debt Securities are issued to the Trust or a Trustee of the
Trust in connection with the issuance of Trust Securities and (i) there shall
have occurred any event that would constitute an Event of Default, (ii) the
Company shall be in default with respect to its payment of any obligations under
the Guarantee or Common Securities Guarantee, or (iii) the Company shall have
given notice of its election to defer payments of interest on such Subordinated
Debt Securities by extending the interest payment period as provided in the
Subordinated Debt Securities Indenture and such period, or any extension
thereof, shall be continuing, then (a) the Company shall not declare or pay
dividends on, or make a distribution with respect to or redeem, purchase or
acquire, or make a liquidation payment with respect to, any of its capital stock
and (b) the Company shall not make any payment of interest, principal or
premium, if any, on or repay, repurchase or redeem any debt securities issued by
the Company which rank pari passu with or junior to such Subordinated Debt
Securities; provided, however, that, restriction (a) above does not apply to any
stock dividends paid by the Company where the dividend stock is the same stock
as that on which the dividend is being paid.
 
     In the event Subordinated Debt Securities are issued to the Trust or a
Trustee of the Trust in connection with the issuance of Trust Securities, for so
long as the Trust Securities remain outstanding, the Company will covenant (i)
to directly or indirectly maintain 100% ownership of the Common Securities;
provided, however, that any permitted successor of the Company under the
Subordinated Debt Securities Indenture may succeed
 
                                       11
<PAGE>   14
 
to the Company's ownership of the Common Securities and (ii) to use its
reasonable efforts to cause the Trust (a) to remain a statutory business trust,
except in connection with the distribution of Subordinated Debt Securities to
the holders of Trust Securities in liquidation of the Trust, the redemption of
all of the Trust Securities, or certain mergers, consolidations or
amalgamations, each as permitted by the Declaration, and (b) to otherwise
continue to be classified as a grantor trust for United States federal income
tax purposes.
 
                    DESCRIPTION OF THE PREFERRED SECURITIES
 
     The Trust may issue, from time to time, only one series of Preferred
Securities having terms described in the Prospectus Supplement relating thereto.
The Declaration authorizes the Regular Trustees of the Trust to issue on behalf
of the Trust one series of Preferred Securities. The Declaration will be
qualified as an indenture under the Trust Indenture Act.
 
     The Preferred Securities will have such terms, including distribution,
redemption, voting and liquidation rights and such other preferred, deferred or
other special rights or such restrictions as shall be set forth in the
Declaration or made part of the Declaration by the Trust Indenture Act.
Reference is made to the applicable Prospectus Supplement relating to the
Preferred Securities for specific terms, including (i) the distinctive
designation of the Preferred Securities, (ii) the number of Preferred Securities
and the date or dates upon which distributions shall be payable (provided,
however, that, distributions on the Preferred Securities shall be payable on a
quarterly basis to holders of the Preferred Securities as of a record date in
each quarter during which the Preferred Securities are outstanding), (iii)
whether distributions on Preferred Securities issued by the Trust shall be
cumulative, and, in the case of Preferred Securities having such cumulative
distribution rights, the date or dates or method of determining the date or
dates from which distributions on Preferred Securities shall be cumulative, (iv)
the amount or amounts which shall be paid out of the assets of the Trust to the
holders of Preferred Securities upon voluntary or involuntary dissolution,
winding-up or termination of the Trust, (v) the obligation, if any, of the Trust
to purchase or redeem Preferred Securities and the price or prices at which, the
period or periods within which and the terms and conditions upon which the
Preferred Securities shall be purchased or redeemed, in whole or in part,
pursuant to such obligation, (vi) the voting rights, if any, of Preferred
Securities in addition to those required by law, including the number of votes
per Preferred Security and any requirement for the approval by the holders of
Preferred Securities, as a condition to specified action or amendments to the
Declaration, and (vii) any other relevant rights, preferences, privileges,
limitations or restrictions on Preferred Securities consistent with the
Declaration and applicable law.
 
     All Preferred Securities offered hereby will be guaranteed by the Company
to the extent set forth below under "Description of the Guarantee". Certain
United States federal income tax considerations applicable to any offering of
Preferred Securities will be described in the Prospectus Supplement relating
thereto.
 
     In connection with the issuance of Preferred Securities, the Trust will
issue Common Securities having such terms including distribution, redemption,
voting and liquidation rights or such restrictions as shall be set forth
therein. The terms of the Common Securities will be substantially identical to
the terms of the Preferred Securities and the Common Securities, will rank pari
passu, and payments will be made thereon pro rata with the Preferred Securities
except that, upon an event of default under the Declaration, the rights of the
holders of the Common Securities to payment in respect of distributions and
payments upon liquidation, redemption and otherwise will be subordinated to the
rights of the holders of the Preferred Securities. Except in certain limited
circumstances, the Common Securities will also carry the right to vote and to
appoint, remove or replace any of the Trustees of the Trust. All of the Common
Securities will be directly or indirectly owned by the Company.
 
                                       12
<PAGE>   15
 
                          DESCRIPTION OF THE GUARANTEE
 
   
     Set forth below is a summary of information concerning the Guarantee that
will be executed and delivered by the Company for the benefit of the holders,
from time to time, of Preferred Securities. The Bank will have no obligation
under the Guarantee. The Guarantee will be qualified as an indenture under the
Trust Indenture Act. Harris Trust and Savings Bank will act as indenture trustee
under the Guarantee (the "Guarantee Trustee"). The terms of the Guarantee will
be those set forth in the Guarantee and those made part of the Guarantee by the
Trust Indenture Act. This summary does not purport to be complete and is subject
in all respects to the provisions of, and is qualified in its entirety by
reference to, the form of Guarantee, which is filed as an exhibit to the
Registration Statement of which this Prospectus forms a part, and the Trust
Indenture Act. The Guarantee will be held by the Guarantee Trustee for the
benefit of the holders of the Preferred Securities.
    
 
GENERAL
 
     Pursuant to the Guarantee, the Company will irrevocably and unconditionally
agree, to the extent set forth herein, to pay in full to the holders of the
Preferred Securities, the Guarantee Payments (as defined herein) (except to the
extent paid by the Trust), as and when due, regardless of any defense, right of
set-off or counterclaim which the Trust may have or assert. The following
payments with respect to Preferred Securities (the "Guarantee Payments"), to the
extent not paid by the Trust will be subject to the Guarantee (without
duplication): (i) any accrued and unpaid distributions that are required to be
paid on the Preferred Securities, to the extent the Company has made a payment
of interest or principal on the Subordinated Debt Securities, (ii) the
redemption price, including all accrued and unpaid distributions thereon,
including interest thereon to the date of redemption (the "Redemption Price"),
to the extent the Company has made a payment of interest or principal on the
Subordinated Debt Securities with respect to any Preferred Securities called for
redemption by the Trust and (iii) upon a voluntary or involuntary dissolution,
winding-up or termination of the Trust (other than in connection with the
distribution of Subordinated Debt Securities to the holders of Preferred
Securities or the redemption of all the Preferred Securities upon the redemption
or maturity of the Subordinated Debt Securities) the lesser of (a) the aggregate
of the liquidation amount and all accrued and unpaid distributions on the
Preferred Securities to the date of payment to the extent the Trust has funds
available therefor or (b) the amount of assets of the Trust remaining available
for distribution to holders of the Preferred Securities in liquidation of the
Trust. The Company's obligation to make a Guarantee Payment may be satisfied by
direct payment of the required amounts by the Company to the holders of
Preferred Securities or by causing the Trust to pay such amounts to such
holders.
 
   
     The Guarantee will be a full and unconditional guarantee on a subordinated
basis with respect to the Preferred Securities from the time of issuance, but
will not apply to any payment of distributions, except to the extent the Trust
shall have funds available therefor as a result of payments of interest or
principal on the Subordinated Debt Securities by the Company. If the Company
does not make interest payments on the Subordinated Debt Securities purchased by
the Trust, the Trust will not pay distributions on the Preferred Securities and
will not have funds available therefor. See "Particular Terms of Subordinated
Debt Securities Issued in Connection with Preferred Securities."
    
 
   
     The obligations of the Company under the Declaration, the Guarantee, the
Indenture with respect to the Subordinated Debt Securities issued in connection
with the Preferred Securities and the Subordinated Debt Securities issued in
connection with the Preferred Securities collectively provide a full and
unconditional guarantee on a subordinated basis by the Company of payments due
on the Preferred Securities to the extent the Trust has funds available therefor
as a result of payments of interest or principal on the Subordinated Debt
Securities by the Company.
    
 
     The Company has also agreed to irrevocably and unconditionally guarantee
the obligations of the Trust with respect to the Common Securities (the "Common
Securities Guarantee") to the same extent as the Guarantee, except that, upon an
event of default under the Subordinated Debt Securities Indenture, holders of
Preferred Securities under the Guarantee will have priority over holders of
Common Securities under the
 
                                       13
<PAGE>   16
 
Common Securities Guarantee with respect to distributions and payments on
liquidation, redemption or otherwise.
 
CERTAIN COVENANTS OF THE COMPANY
 
     In the Guarantee, the Company will covenant that, so long as any Preferred
Securities issued by the Trust remain outstanding, if there shall have occurred
any event that would constitute an event of default under the Guarantee or the
Declaration, then (a) the Company shall not declare or pay any dividend on, or
make any distribution with respect to, or redeem, purchase, acquire or make a
liquidation payment with respect to, any of its capital stock and (b) shall not
make any payment of interest, principal or premium, if any, on or repay,
repurchase or redeem any debt securities issued by the Company which rank pari
passu with or junior to such Subordinated Debt Securities. However, the
Guarantee will except from the foregoing any stock dividends paid by the
Company, where the dividend stock is the same stock as that on which the
dividend is being paid.
 
MODIFICATIONS OF THE GUARANTEE; ASSIGNMENT
 
     Except with respect to any changes that do not adversely affect the rights
of holders of Preferred Securities (in which case no vote will be required), the
Guarantee may be amended only with the prior approval of the holders of not less
than 66 2/3% in liquidation amount of the Preferred Securities then outstanding.
The manner of obtaining any such approval of holders of the Preferred Securities
will be set forth in an accompanying Prospectus Supplement. All guarantees and
agreements contained in the Guarantee shall bind the successors, assigns,
receivers, trustees and representatives of the Company and shall inure to the
benefit of the holders of the Preferred Securities then outstanding.
 
EVENTS OF DEFAULT
 
     An event of default under the Guarantee will occur upon the failure of the
Company to make any of the payments required by the Guarantee or to perform its
other obligations thereunder. The holders of a majority in liquidation amount of
the Preferred Securities have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Guarantee Trustee in
respect of the Guarantee or to direct the exercise of any trust or power
conferred upon the Guarantee Trustee under the Guarantee.
 
   
     If the Guarantee Trustee fails to enforce the Guarantee, any holder of
Preferred Securities may institute a legal proceeding directly against the
Company to enforce the Guarantee Trustee's rights under the Guarantee without
first instituting a legal proceeding against the Trust, the Guarantee Trustee or
any other person or entity.
    
 
     The Company will be required to provide annually to the Guarantee Trustee a
statement as to the performance by the Company of certain of its obligations
under the Guarantee and as to any default in such performance.
 
     The Company is required to file annually with the Guarantee Trustee an
officer's certificate as to the Company's compliance with all conditions under
the Guarantee.
 
INFORMATION CONCERNING THE GUARANTEE TRUSTEE
 
     The Guarantee Trustee, prior to the occurrence of a default, undertakes to
perform only such duties as are specifically set forth in the Guarantee and,
after default with respect to the Guarantee, shall exercise the same degree of
care as a prudent individual would exercise in the conduct of its own affairs.
Subject to such provision, the Guarantee Trustee is under no obligation to
exercise any of the powers vested in it by the Guarantee at the request of any
holder of Preferred Securities unless it is offered reasonable indemnity against
the costs, expenses and liabilities that might be incurred thereby.
 
TERMINATION OF THE GUARANTEE
 
     The Guarantee will terminate as to the Preferred Securities upon full
payment of the Redemption Price of all Preferred Securities, upon distribution
of the Subordinated Debt Securities held by the Trust to the
 
                                       14
<PAGE>   17
 
holders of the Preferred Securities or upon full payment of the amounts payable
in accordance with the Declaration upon liquidation of the Trust. The Guarantee
will continue to be effective or will be reinstated, as the case may be, if at
any time any holder of Preferred Securities must restore payment of any sums
paid under the Preferred Securities or the Guarantee.
 
STATUS OF THE GUARANTEE
 
     The Guarantee will constitute an unsecured obligation of the Company and
will rank (i) subordinate and junior in right of payment to all other
liabilities of the Company (other than the Common Securities Guarantee or any
guarantee now or hereafter entered into by the Company in respect of any
preferred or preference stock of any Affiliate of the Company), (ii) pari passu
with the most senior preferred or preference stock now or hereafter issued by
the Company and with any guarantee now or hereafter entered into by the Company
in respect of any preferred or preference stock of any Affiliate of the Company
and (iii) senior to the Company's Common Stock. The terms of the Preferred
Securities provide that each holder of Preferred Securities by acceptance
thereof agrees to the subordination provisions and other terms of the Guarantee.
 
     The Guarantee will constitute a guarantee of payment and not of collection
(that is, the guaranteed party may institute a legal proceeding directly against
the guarantor to enforce its rights under the Guarantee without instituting a
legal proceeding against any other person or entity).
 
GOVERNING LAW
 
     The Guarantee will be governed by and construed in accordance with the
internal laws of the State of New York.
 
                         DESCRIPTION OF PREFERRED STOCK
 
     The following description of the terms of the Preferred Stock sets forth
certain general terms and provisions of the Preferred Stock to which any
Prospectus Supplement may relate. Certain other terms of any series of the
Preferred Stock offered by any Prospectus Supplement will be described in such
Prospectus Supplement. The description of certain provisions of the Preferred
Stock set forth below and in any Prospectus Supplement does not purport to be
complete and is subject to and qualified in its entirety by reference to the
Company's Restated Articles of Incorporation (the "Articles of Incorporation"),
and the certificate of determination (a "Certificate of Determination") relating
to each series of the Preferred Stock which will be filed with the Commission
and incorporated by reference as an exhibit to the Registration Statement of
which this Prospectus is a part at or prior to the time of the issuance of such
series of the Preferred Stock.
 
AUTHORIZED CAPITAL STOCK
 
     The authorized capital stock of the Company consists of 30,000,000 shares
of Common Stock, $1 par value, 200,000 shares of preferred stock, $50 par value
("preferred stock of the Company," which term, as used herein, includes the
Preferred Stock offered hereby), 500,000 shares of cumulative preferred stock,
$100 par value ("Cumulative Preferred Stock"), and 2,000,000 shares of
preference stock, $20 par value (the "Preference Stock"). As of June 30, 1995
there were outstanding 23,898,709 shares of Common Stock and 40,000 shares of
Cumulative Preferred Stock. No shares of preferred stock of the Company or
Preference Stock of the Company were outstanding on this date.
 
     The Company is required to redeem 8,000 shares annually through 1999 of the
Cumulative Preferred Stock at par value plus accrued dividends. All outstanding
shares of Cumulative Preferred Stock are redeemable at the option of the Company
at any time upon 30 days' notice at par value plus accrued dividends and a
premium equal to the dividend rate in the first year commencing December 1, 1979
and declining ratably each year thereafter to par value. In addition, the
Company may redeem up to 8,000 shares of Cumulative Preferred Stock (but not
more than 45,000 shares in the aggregate) at par value plus accrued dividends on
any mandatory redemption date without payment of a premium. The dividend rate on
the Cumulative Preferred Stock is 9.5% and is cumulative.
 
                                       15
<PAGE>   18
 
     The Articles of Incorporation provide that in the event of involuntary
liquidation, (a) before distributions may be made to holders of any other class
of Junior Stock (as hereinafter defined), holders of Cumulative Preferred Stock
are entitled to payment in full at par value, together with accrued dividends.
 
     The holders of shares of the Cumulative Preferred Stock are not entitled to
notice of any meetings of shareholders or to vote upon the election of directors
or upon any question affecting the management or affairs of the Company, except
to the extent otherwise provided by law or the Certificate of Determination for
the Cumulative Preferred Stock. The Certificate of Determination for the
Cumulative Preferred Stock provides that the holders of all shares of Cumulative
Preferred Stock, voting as a class, are entitled to elect two directors to the
Board of Directors of the Company whenever four quarterly dividends upon any
shares of Cumulative Preferred Stock are in arrears or any mandatory redemption
payment is one year in arrears, until all dividends in default and mandatory
redemption payments have been made. In addition, an affirmative vote of the
holders of all shares of Cumulative Preferred Stock outstanding is required for
the authorization or creation (or increase in the authorized amount) of any
class of stock ranking senior to the Cumulative Preferred Stock. It is, however,
permissible to issue up to 200,000 shares of preferred stock of the Company
senior to the Cumulative Preferred Stock. The affirmative vote of 66 2/3% of the
outstanding shares of Cumulative Preferred Stock is also required in order (a)
to amend the Articles of Incorporation in certain respects that would adversely
affect the rights of the holders of Cumulative Preferred Stock, (b) to increase
the amount of Cumulative Preferred Stock authorized by the Articles of
Incorporation or the authorization or creation of any class of stock ranking on
a parity with the Cumulative Preferred Stock, (c) for the Company to sell, lease
or convey substantially all of the business of the Company, the parting of
control thereof or the merger or consolidation of the Company into another
corporation in which the Company is not the surviving corporation, or (d) to
issue or reissue any shares of Cumulative Preferred Stock ranking on a parity
with the Cumulative Preferred Stock unless certain financial tests are met.
 
ISSUANCE OF PREFERRED STOCK
 
     Under the Articles of Incorporation, the Board of Directors of the Company
is authorized without further shareholder action to provide for the issuance of
up to 200,000 shares of preferred stock of the Company in preference to the
holders of Cumulative Preferred Stock, Preference Stock and Common Stock (the
Common Stock, Cumulative Preferred Stock and Preference Stock being herein
referred to as "Junior Stock"), in one or more series, with such dividend
rights, dividend rate, conversion rights, voting rights, rights and time of
redemption (including sinking fund provisions), redemption price or prices,
liquidation preferences and designation, as shall be stated in the resolution or
resolutions providing for the issue of a series of such preferred stock of the
Company adopted, at any time or from time to time, by the Board of Directors of
the Company. The Board of Directors may also increase or decrease (but not below
the number of shares of such series then outstanding) the number of shares of
any such series subsequent to the issue of that series.
 
     As described under "Description of Depositary Shares," the Company may, at
its option, elect to offer Depositary Shares evidenced by depositary receipts
(the "Depositary Receipts"), each representing a fraction (to be specified in
the Prospectus Supplement relating to the particular series of the Preferred
Stock) of a share of the particular series of the Preferred Stock issued and
deposited with a depositary, in lieu of offering full shares of such series of
the Preferred Stock.
 
     The Preferred Stock shall have the dividend, liquidation, redemption and
voting rights set forth below unless otherwise provided in a Prospectus
Supplement relating to a particular series of the Preferred Stock. Reference is
made to the Prospectus Supplement relating to the particular series of the
Preferred Stock offered thereby for specific terms, including: (a) the
designation of such Preferred Stock and the number of shares offered; (b) the
amount of liquidation preference per share; (c) the initial public offering
price at which such Preferred Stock will be issued; (d) the dividend rate (or
method of calculation), the dates on which dividends shall be payable and the
dates from which dividends shall commence to cumulate, if any; (e) any
redemption or sinking fund provisions; (f) any conversion rights; (g) whether
the Company has elected to offer Depositary Shares as described below under
"Description of Depositary Shares;" and (h) any additional voting, dividend,
liquidation, redemption, sinking fund and other rights, preferences, privileges,
limitations and restrictions.
 
                                       16
<PAGE>   19
 
     The Preferred Stock will, when issued, be fully paid and nonassessable and
will have no preemptive rights. The rights of the holders of each series of the
Preferred Stock to receive dividends and distributions of assets will be
subordinate to those of the Company's general creditors, but superior to the
rights of holders of Junior Stock. See "Description of Common Stock" for a
description of certain provisions of State and federal law and the Articles of
Incorporation and Bylaws of the Company which may affect holders of Preferred
Stock.
 
DIVIDEND RIGHTS
 
     Holders of the Preferred Stock of each series will be entitled to receive,
when, as and if declared by the Board of Directors of the Company, out of funds
of the Company legally available therefor, cash dividends on such dates and at
such rates as are set forth in, or as are determined by the method described in,
the Prospectus Supplement relating to such series of the Preferred Stock. Such
rate may be fixed or variable or both. Each such dividend will be payable to the
holders of record as they appear on the stock books of the Company (or, if
applicable, the records of the Depositary (as hereinafter defined) referred to
under "Description of Depositary Shares") on such record dates, fixed by the
Board of Directors of the Company, as specified in the Prospectus Supplement
relating to such series of Preferred Stock.
 
     Such dividends may be cumulative or noncumulative, as provided in the
Prospectus Supplement relating to such series of Preferred Stock. If the Board
of Directors of the Company fails to declare a dividend payable on a dividend
payment date on any series of Preferred Stock for which dividends are
noncumulative, then the right to receive a dividend in respect of the dividend
period ending on such dividend payment date will be lost, and the Company will
have no obligation to pay the dividend accrued for such period, whether or not
dividends on such series are declared payable on any future dividend payment
dates. Dividends on the shares of each series of Preferred Stock for which
dividends are cumulative will accrue from the date on which the Company
initially issues shares of such series.
 
     Unless otherwise specified in the applicable Prospectus Supplement, so long
as the shares of any series of the Preferred Stock are outstanding, unless (a)
full dividends (including if such Preferred Stock is cumulative, dividends for
prior dividend periods) have been paid or declared and set apart for payment on
all outstanding shares of the Preferred Stock of such series and all other
classes and series of preferred stock of the Company (other than Junior Stock)
and (b) the Company is not in default or in arrears with respect to the
mandatory or optional redemption or mandatory repurchase or other mandatory
retirement of, or with respect to any sinking or other analogous fund for, any
shares of Preferred Stock of such series or any shares of any other preferred
stock of the Company of any class or series (other than Junior Stock), the
Company may not declare any dividends on any shares of Common Stock of the
Company or any other stock of the Company ranking as to dividends or
distributions of assets junior to such series of Preferred Stock, or make any
payment on account of, or set apart money for, the purchase, redemption or other
retirement of, or for a sinking or other analogous fund for, any shares of
Junior Stock or make any distribution in respect thereof, whether in cash or
property or in obligations or stock of the Company, other than Junior Stock
which is neither convertible into, nor exchangeable or exercisable for, any
securities of the Company other than Junior Stock.
 
LIQUIDATION PREFERENCES
 
     Unless otherwise specified in the applicable Prospectus Supplement, in the
event of any liquidation, dissolution or winding up of the Company, whether
voluntary or involuntary, the holders of each series of the Preferred Stock will
be entitled to receive out of the assets of the Company available for
distribution to shareholders, before any distribution of assets is made to the
holders of Junior Stock, the amount set forth in the Prospectus Supplement
relating to such series of the Preferred Stock. If, upon any voluntary or
involuntary liquidation, dissolution or winding up of the Company, the amounts
payable with respect to the Preferred Stock of any series and any other shares
of preferred stock of the Company (including any other series of the Preferred
Stock) ranking as to any such distribution on a parity with such series of the
Preferred Stock are not paid in full, the holders of the Preferred Stock of such
series and of such other shares of preferred stock of the Company will share
ratably in any such distribution of assets of the Company in proportion to the
full respective preferential amounts to which they are entitled. After payment
to the holders of the Preferred Stock
 
                                       17
<PAGE>   20
 
of each series of the full preferential amounts of the liquidating distribution
to which they are entitled, the holders of each such series of the Preferred
Stock will be entitled to no further participation in any distribution of assets
by the Company.
 
REDEMPTION
 
     A series of the Preferred Stock may be redeemable, in whole or from time to
time in part, at the option of the Company, and may be subject to mandatory
redemption pursuant to a sinking fund or otherwise, in each case upon terms, at
the times and at the redemption prices set forth in the Prospectus Supplement
relating to such series. Unless otherwise provided in the applicable Prospectus
Supplement, shares of the Preferred Stock redeemed by the Company will be
restored to the status of authorized but unissued shares of preferred stock of
the Company.
 
     In the event that fewer than all of the outstanding shares of a series of
the Preferred Stock are to be redeemed, whether by mandatory or optional
redemption, the number of shares to be redeemed will be determined by lot or pro
rata (subject to rounding to avoid fractional shares) as may be determined by
the Company or by any other method as may be determined by the Company in its
sole discretion to be equitable. From and after the redemption date (unless
default is made by the Company in providing for the payment of the redemption
price plus accumulated and unpaid dividends, if any) dividends will cease to
accumulate on the shares of the Preferred Stock called for redemption and all
rights of the holders thereof (except the right to receive the redemption price
plus accumulated and unpaid dividends, if any) will cease.
 
     Unless otherwise specified in the applicable Prospectus Supplement, so long
as any dividends on shares of any series of the Preferred Stock or any other
series of preferred stock of the Company ranking on a parity as to dividends and
distribution of assets with such series of the Preferred Stock are in arrears,
no shares of any such series of the Preferred Stock or such other series of
preferred stock of the Company will be redeemed (whether by mandatory or
optional redemption) unless all such shares are simultaneously redeemed, and the
Company will not purchase or otherwise acquire any such shares; provided,
however, that the foregoing will not prevent the purchase or acquisition of such
shares pursuant to a purchase or exchange offer made on the same terms to
holders of all such shares outstanding.
 
CONVERSION RIGHTS
 
     The terms, if any, on which shares of Preferred Stock of any series may be
exchanged for or converted (mandatorily or otherwise) into shares of Common
Stock or another series of Preferred Stock will be set forth in the Prospectus
Supplement relating thereto. See "Description of Common Stock."
 
VOTING RIGHTS
 
     Except as indicated below or in a Prospectus Supplement relating to a
particular series of the Preferred Stock, or except as required by applicable
law, the holders of the Preferred Stock will not be entitled to vote for any
purpose.
 
     Unless otherwise specified in the applicable Prospectus Supplement, so long
as any shares of the Preferred Stock of a series remain outstanding, the consent
or the affirmative vote of the holders of at least a majority of the votes
entitled to be cast with respect to the then outstanding shares of such series
of the Preferred Stock together with any Other Preferred Stock (as defined
below), voting as one class, either expressed in writing or at a meeting called
for that purpose, will be necessary (a) to permit, effect or validate the
authorization, or any increase in the authorized amount, of any class or series
of shares of the Company ranking prior to the Preferred Stock of such series as
to dividends, voting or upon distribution of assets and (b) to repeal, amend or
otherwise change any of the provisions applicable to the Preferred Stock of such
series in any manner which adversely affects the powers, preferences, voting
power or other rights or privileges of such series of the Preferred Stock. In
case any series of the Preferred Stock would be so affected by any such action
referred to in clause (b) above in a different manner than one or more series of
the Other Preferred Stock then outstanding, the holders of shares of the
Preferred Stock of such series, together with any series of the Other Preferred
Stock which will be similarly affected, will be entitled to vote as a class, and
the Company
 
                                       18
<PAGE>   21
 
will not take such action without the consent or affirmative vote, as above
provided, of at least a majority of the total number of votes entitled to be
cast with respect to each such series of the Preferred Stock and the Other
Preferred Stock, then outstanding, in lieu of the consent or affirmative vote
hereinabove otherwise required.
 
     Unless otherwise specified in the applicable Prospectus Supplement, with
respect to any matter as to which the Preferred Stock of any series is entitled
to vote, holders of the Preferred Stock of such series and any other series of
preferred stock of the Company ranking on a parity with such series of the
Preferred Stock as to dividends and distributions of assets and which by its
terms provides for similar voting rights (the "Other Preferred Stock") will be
entitled to cast the number of votes set forth in the Prospectus Supplement with
respect to that series of Preferred Stock. As a result of the provisions
described in the preceding paragraph requiring the holders of shares of a series
of the Preferred Stock to vote together as a class with the holders of shares of
one or more series of Other Preferred Stock, it is possible that the holders of
such shares of Other Preferred Stock could approve action that would adversely
affect such series of Preferred Stock, including the creation of a class of
capital stock ranking prior to such series of Preferred Stock as to dividends,
voting or distributions of assets.
 
     As more fully described below under "Description of Depositary Shares," if
the Company elects to issue Depositary Shares, each representing a fraction of a
share of a series of the Preferred Stock, each such Depositary Share will, in
effect, be entitled to such fraction of a vote per Depositary Share.
 
TRANSFER AGENT AND REGISTRAR
 
     Unless otherwise indicated in a Prospectus Supplement relating thereto, the
Company will be the transfer agent, dividend and redemption price disbursement
agent and registrar for shares of each series of the Preferred Stock.
 
                        DESCRIPTION OF DEPOSITARY SHARES
 
     The description set forth below and in any Prospectus Supplement of certain
provisions of the Deposit Agreement (as defined below) and of the Depositary
Shares and Depositary Receipts does not purport to be complete and is subject to
and qualified in its entirety by reference to the Deposit Agreement and
Depositary Receipts relating to each series of the Preferred Stock which will be
filed with the Commission and incorporated by reference as an exhibit to the
Registration Statement of which this Prospectus is a part at or prior to the
time of the issuance of such series of the Preferred Stock. The forms of Deposit
Agreement and Depositary Receipt are filed as exhibits to the Registration
Statement of which this Prospectus is a part.
 
GENERAL
 
     The Company may, at its option, elect to offer fractional shares of
Preferred Stock rather than full shares of Preferred Stock. In the event such
option is exercised, the Company will issue to the public receipts for
Depositary Shares, each of which will represent a fraction (to be set forth in
the Prospectus Supplement relating to a particular series of the Preferred
Stock) of a share of a particular series of the Preferred Stock as described
below.
 
     The shares of any series of the Preferred Stock represented by Depositary
Shares will be deposited under a separate deposit agreement (the "Deposit
Agreement") among the Company, a bank or trust company selected by the Company
(the "Depositary") and the holders from time to time of the Depositary Receipts.
Subject to the terms of the Deposit Agreement, each owner of a Depositary Share
will in general be entitled, in proportion to the applicable fraction of a share
of Preferred Stock represented by such Depositary Share, to all the rights and
preferences of the Preferred Stock represented thereby (including dividend,
voting, redemption and liquidation rights).
 
     The Depositary Shares relating to any series of the Preferred Stock will be
evidenced by Depositary Receipts issued pursuant to the related Deposit
Agreement. Depositary Receipts will be distributed to those persons purchasing
such Depositary Shares in accordance with the terms of the offering made by the
related Prospectus Supplement.
 
                                       19
<PAGE>   22
 
     Upon surrender of Depositary Receipts at the office of the Depositary and
upon payment of the charges provided in the Deposit Agreement and subject to the
terms thereof, a holder of Depositary Receipts is entitled to have the
Depositary deliver to such holder the whole shares of Preferred Stock underlying
the Depositary Shares evidenced by the surrendered Depositary Receipts. However,
there may be no market for the underlying Preferred Stock and once the
underlying Preferred Stock is withdrawn from the Depositary, it may not be
redeposited.
 
DIVIDENDS AND OTHER DISTRIBUTIONS
 
     The Depositary will distribute all cash dividends or other cash
distributions received in respect of the Preferred Stock to the record holders
of Depositary Receipts relating to such Preferred Stock in proportion, insofar
as practicable, to the respective numbers of Depositary Shares evidenced by such
Depositary Receipts held by such holders on the relevant record date. The
Depositary will distribute only such amount, however, as can be distributed
without attributing to any holder of Depositary Receipts a fraction of one cent,
and any balance not so distributed will be added to and treated as part of the
next sum received by the Depositary for distribution to record holders of
Depositary Receipts then outstanding.
 
     In the event of a distribution other than in cash, the Depositary will
distribute such amounts of the securities or property received by it as are, as
nearly as practicable, in proportion to the respective numbers of Depositary
Shares evidenced by the Depositary Receipts held by such holders on the relevant
record date, unless the Depositary determines that it is not feasible to make
such distribution, in which case the Depositary may, with the approval of the
Company, adopt such method as it deems equitable and practicable for the purpose
of effecting such distribution, including the sale of such securities or
property.
 
     The Deposit Agreement will also contain provisions relating to the manner
in which any subscription or similar rights offered by the Company to holders of
the Preferred Stock will be made available to holders of Depositary Receipts.
 
     The amount distributed in all of the foregoing cases will be reduced by any
amounts required to be withheld by the Company or the Depositary on account of
taxes and governmental charges.
 
REDEMPTION OF DEPOSITARY SHARES
 
     If a series of the Preferred Stock represented by Depositary Shares is
subject to redemption, the Depositary Shares will be redeemed from the proceeds
received by the Depositary resulting from the redemption, in whole or in part,
of such series of the Preferred Stock held by the Depositary. The Depositary
will mail notice of redemption not less than 30 and not more than 60 days prior
to the date fixed for redemption to the record holders of the Depositary
Receipts evidencing the Depositary Shares to be so redeemed at their respective
addresses appearing in the Depositary's books. The redemption price per
Depositary Share will be equal to the applicable fraction of the redemption
price per share payable with respect to such series of the Preferred Stock plus
all money and other property, if any, payable with respect to such Depositary
Share, including all amounts payable by the Company in respect of any
accumulated but unpaid dividends. Whenever the Company redeems shares of
Preferred Stock held by the Depositary, the Depositary will redeem as of the
same redemption date the number of Depositary Shares representing shares of
Preferred Stock so redeemed. If less than all the Depositary Shares are to be
redeemed, the Depositary Shares to be redeemed will be selected by lot or pro
rata (subject to rounding to avoid fractions of Depositary Shares) as may be
determined by the Depositary.
 
     After the date fixed for redemption, the Depositary Shares so called for
redemption will no longer be deemed to be outstanding and all rights of the
holders of Depositary Receipts evidencing such Depositary Shares will cease,
except the right to receive the moneys payable upon such redemption and any
moneys or other property to which such holders were entitled upon such
redemption upon surrender to the Depositary of the Depositary Receipts
evidencing such Depositary Shares.
 
                                       20
<PAGE>   23
 
VOTING THE PREFERRED STOCK
 
     Upon receipt of notice of any meeting or action to be taken by written
consent at or as to which the holders of the Preferred Stock are entitled to
vote or consent, the Depositary will mail the information contained in such
notice of meeting or action to the record holders of the Depositary Receipts
evidencing the Depositary Shares relating to such Preferred Stock. Each record
holder of such Depositary Receipts on the record date (which will be the same
date as the record date for the Preferred Stock) will be entitled to instruct
the Depositary as to the exercise of the voting rights or the giving or refusal
of consent, as the case may be, pertaining to the number of shares of the
Preferred Stock represented by the Depositary Shares evidenced by such holder's
Depositary Receipts. The Depositary will endeavor, insofar as practicable, to
vote, or give or withhold consent with respect to, the maximum number of whole
shares of the Preferred Stock represented by all Depositary Shares as to which
any particular voting or consent instructions are received, and the Company will
agree to take all action which may be deemed necessary by the Depositary in
order to enable the Depositary to do so. The Depositary will abstain from
voting, or giving consents with respect to, shares of the Preferred Stock to the
extent it does not receive specific instructions from the holders of Depositary
Receipts evidencing Depositary Shares representing such Preferred Stock.
 
AMENDMENT AND TERMINATION OF THE DEPOSIT AGREEMENT
 
     The form of Depositary Receipt evidencing the Depositary Shares relating to
any series of Preferred Stock and any provision of the related Deposit Agreement
may at any time and from time to time be amended by agreement between the
Company and the Depositary in any respect which they may deem necessary or
desirable. However, any amendment which imposes or increases any fees, taxes or
charges upon holders of Depositary Shares or Depositary Receipts relating to any
series of Preferred Stock or which materially and adversely alters the existing
rights of such holders will not be effective unless such amendment has been
approved by the record holders of Depositary Receipts evidencing at least a
majority of such Depositary Shares then outstanding. Notwithstanding the
foregoing, no such amendment may impair the right of any holder of Depositary
Shares or Depositary Receipts to receive any moneys or other property to which
such holder may be entitled under the terms of such Depositary Receipts or the
Deposit Agreement at the times and in the manner and amount provided for
therein. A Deposit Agreement may be terminated by the Company or the Depositary
only after (a) all outstanding Depositary Shares relating thereto have been
redeemed and any accumulated and unpaid dividends on the Preferred Stock
represented by the Depositary Shares, together with all other moneys and
property, if any, to which holders of the related Depositary Receipts are
entitled under the terms of such Depositary Receipts or the related Deposit
Agreement, have been paid or distributed as provided in the Deposit Agreement or
provision therefor has been duly made, (b) there has been a final distribution
in respect of the Preferred Stock of the relevant series in connection with any
liquidation, dissolution or winding up of the Company and such distribution has
been distributed to the holders of the related Depositary Receipts, or (c) in
the event the Depositary Shares relate to a series of Preferred Stock which is
convertible into shares of Common Stock or another series of Preferred Stock,
all outstanding Depositary Shares have been converted into shares of Common
Stock or another series of Preferred Stock.
 
MISCELLANEOUS
 
     The Depositary will forward to record holders of Depositary Receipts, at
their respective addresses appearing in the Depositary's books, all reports and
communications from the Company which are delivered to the Depositary and which
the Company is required to furnish to the holders of the Preferred Stock or
Depositary Receipts.
 
     The Company will pay all transfer and other taxes and governmental charges
arising solely from the existence of the depositary arrangements. The Company
will pay charges of the Depositary in connection with the initial deposit of the
Preferred Stock and the initial issuance of the Depositary Receipts evidencing
the Depositary Shares, any redemption of the Preferred Stock and any withdrawals
of Preferred Stock by the holders of Depositary Shares. Holders of Depositary
Shares will pay other transfer and other taxes and
 
                                       21
<PAGE>   24
 
governmental charges and such other charges as are expressly provided in the
Deposit Agreement to be for their accounts.
 
     The Deposit Agreement will contain provisions relating to adjustments in
the fraction of a share of Preferred Stock represented by a Depositary Share in
the event of a change in par value, split-up, combination or other
reclassification of the Preferred Stock or upon any recapitalization, merger or
sale of substantially all of the assets of the Company as an entirety.
 
     Neither the Depositary nor any of its agents nor any registrar nor the
Company will be (a) liable if it is prevented or delayed by law or any
circumstance beyond its control in performing its obligations under the Deposit
Agreement, (b) subject to any liability under the Deposit Agreement to holders
of Depositary Receipts other than for the relevant party's gross negligence or
willful misconduct, or (c) obligated to prosecute or defend any legal proceeding
in respect of any Depositary Receipts, Depositary Shares or the Preferred Stock
unless satisfactory indemnity is furnished. They may rely upon written advice of
counsel or accountants, or information provided by holders of Depositary
Receipts or other persons in good faith believed to be competent and on
documents reasonably believed to be genuine.
 
RESIGNATION OR REMOVAL OF DEPOSITARY
 
     The Depositary may resign at any time by delivering to the Company notice
of its election to do so, and the Company may at any time remove the Depositary,
any such resignation or removal to take effect upon the appointment of a
successor Depositary and its acceptance of such appointment. Such successor
Depositary must be appointed within 60 days after delivery of the notice of
resignation or removal.
 
                          DESCRIPTION OF COMMON STOCK
GENERAL
 
   
     The holders of the outstanding shares of Common Stock have full voting
rights, one vote for each share held of record. Shareholders have cumulative
voting rights with respect to the election of directors, if certain conditions
are met. Upon liquidation, dissolution, or winding up of the Company (but
subject to the rights of holders of preferred stock of the Company, Cumulative
Preferred Stock and Preference Stock), the assets legally available for
distribution to holders of Common Stock will be distributed ratably among such
holders. Holders of Common Stock have no preemptive or other subscription or
conversion rights, and no liability for further calls upon shares. The Common
Stock is not subject to assessment. Shares of Common Stock may be issued in
series with a special initial dividend rate as hereinafter described (any such
series, being referred to herein as "Special Common Stock"). No shares of
Special Common Stock are outstanding and the Company does not intend to offer
such securities in the future.
    
 
     Subject to the rights of holders of preferred stock of the Company,
Cumulative Preferred Stock and Preference Stock, holders of Common Stock are
entitled to receive such dividends as may be declared by the Board of Directors
of the Company out of funds legally available therefor. Dividends on all series
of Common Stock must have the same record and payment dates. No series of Common
Stock may have preference over any other series as to the payment of dividends,
but the amount of cash dividends paid may vary among series.
 
     Under the terms of the Articles of Incorporation, the initial dividend rate
on any Special Common Stock issued by the Company must be established by the
Board of Directors of the Company at or before the issuance thereof at an annual
rate greater than four times the last quarterly dividend paid on Common Stock
which is not Special Common Stock (referred to herein as "Original Common
Stock"). The initial dividend rate on any series of Special Common Stock offered
by any Prospectus Supplement will be described in such Prospectus Supplement.
 
     The initial dividend rate on each share of Special Common Stock must be
reduced if the quarterly dividend on a share of Original Common Stock is reduced
and on the same percentage basis. The initial dividend rate on each share of
Special Common Stock must also be increased if the dividend on a share of
Original Common Stock is increased and on the same percentage basis; provided
that at no time may the dividend on a share of Special Common Stock of any
series exceed the greater of (a) one-fourth of the initial
 
                                       22
<PAGE>   25
 
annual dividend rate established at the time of issuance of any such share of
Special Common Stock, or (b) the dividend rate concurrently being paid on each
of the outstanding shares of Original Common Stock. Shares of Special Common
Stock of any series will cease to be shares of Special Common Stock (and will
thereafter be considered to be shares of Original Common Stock) at any time that
the aggregate of all dividends paid during any fiscal year on shares of Special
Common Stock of that series fails to exceed the aggregate of all dividends paid
by the Company during such year on each share of Original Common Stock.
 
     The Company is the transfer agent and registrar for the Common Stock.
 
CERTAIN PROVISIONS OF THE ARTICLES OF INCORPORATION AND BYLAWS
 
     The Company's Articles of Incorporation contain provisions which require a
super-majority vote of the holders of Common Stock in order for certain types of
business combinations to be approved. These provisions are applicable to (a) any
merger or consolidation of the Company with or into a dominant stockholder (as
hereinafter defined) or any entity controlled by a dominant stockholder, (b) any
merger of a dominant stockholder with or into the Company or any corporation
controlled by or under common control with the Company, (c) any sale, lease,
exchange or transfer of all or substantially all of the property and assets of
the Company to a dominant stockholder or any entity controlled by or under
common control with a dominant stockholder, (d) any purchase, lease, exchange,
transfer or acquisition by the Company of all or substantially all of the
property and assets of a dominant stockholder or any entity controlled by or
under common control with a dominant stockholder, (e) any recapitalization of
the Company that would have the effect of increasing the voting power of a
dominant stockholder, and (f) any agreement, contract or other arrangement
providing for any of the foregoing. The term "dominant stockholder" is defined
as any person that, together with any affiliate or associate, beneficially owns
in the aggregate 10% or more of the outstanding Common Stock of the Company.
 
     The affirmative vote of not fewer than 85% of the outstanding shares of
Common Stock must approve a business combination, unless (a) the Board of
Directors of the Company has approved the business combination by the
affirmative vote of (i) not fewer than 65% of its members if the business
combination is approved in advance of the dominant stockholder becoming a
dominant stockholder or the acquisition of shares of Common Stock that caused
the dominant stockholder to become a dominant stockholder has been approved in
advance, or (ii) not fewer than 85% of its members in all other circumstances,
or (b) the Board of Directors of the Company by an affirmative vote of not fewer
than 85% has determined that the cash or fair value of the properties,
securities or other consideration to be received by the holders of Common Stock
in the business combination is not less than the highest per share price paid by
the dominant stockholder in acquiring any of its holdings of the Common Stock.
These provisions may only be amended by an affirmative vote of 65% of the
outstanding shares of the Company's Common Stock, unless there is a dominant
stockholder at the time of the vote, in which event a vote of 85% of the
outstanding shares of Common Stock is required.
 
     California law permits corporations to limit or eliminate the personal
liability of their directors in any action, including actions brought by the
corporation or its shareholders for monetary damages for breach of a director's
fiduciary duty of care. The duty of care requires that, when acting on behalf of
the corporation, a director must act in good faith, in a manner such director
believes to be in the best interests of the corporation and its shareholders and
with such care, including reasonable inquiry, as an ordinarily prudent person in
a like position would use under similar circumstances. As a result, the
available relief to a corporation and its shareholders may be limited to
equitable remedies such as injunction or rescission if a company indemnifies its
directors to the fullest extent permitted by California law.
 
     Article VIII of the Company's Articles of Incorporation and Bylaws limit
the liability of directors of the Company to the Company or its shareholders (in
their capacity as directors, but not in their capacity as officers) to the
fullest extent permitted by California law. Specifically, directors of the
Company are not personally liable to the Company or its shareholders for
monetary damages for breach of a director's fiduciary duty as a director, except
(a) on account of profits made in connection with a purchase or sale of
securities in violation of Section 16(b) of the Exchange Act, (b) if a court of
competent jurisdiction determines that indemnification is unlawful, (c) for acts
or omissions involving intentional misconduct or knowing and
 
                                       23
<PAGE>   26
 
culpable violations of law, (d) for acts or omissions that the director believed
to be contrary to the best interests of the Company or its shareholders or that
involve the absence of good faith on the part of the director, (e) for any
transaction for which the director derived an improper benefit, (f) for acts or
omissions that show a reckless disregard for the director's duty to the Company
or its shareholders in circumstances in which the director was aware, or should
have been aware, in the ordinary course of performing his or her duties, of a
risk of serious injury to the Company or its shareholders, (g) for acts or
omissions that constitute an unexcused pattern of inattention that amounts to an
abdication of the director's duties to the corporation or its shareholders, (h)
for liabilities arising out of transactions in which the director had a personal
interest, (i) for the approval of distributions to the Company's shareholders in
violation of California law, or (j) for the approval of the making by the
Company of any loan of money or property to a director or officer of the Company
or the guarantee of the obligations of any such director or officer in violation
of California law. The inclusion of these provisions in the Company's Articles
of Incorporation and Bylaws may have the effect of reducing the likelihood of
litigation against directors of the Company, even though such an action, if
successful, might otherwise have benefited the Company or its shareholders.
 
CERTAIN PROVISIONS OF STATE AND FEDERAL LAW
 
     Arizona regulates certain business combinations by an "interested
shareholder" of a public corporation if the public corporation (a) has issued
securities under Section 12 of the Exchange Act, (b) has its principal place of
business in the State of Arizona, (c) owns or controls assets located within the
State of Arizona with a fair market value of at least one million dollars, and
(d) has more than 500 employees in the State of Arizona. The Company believes
that these provisions are currently applicable to the Company. A person becomes
an interested shareholder under the Arizona business combination statute upon
the acquisition of 10% or more of the outstanding voting shares of the public
corporation. The term "business combination" is broadly defined to include not
only acquisitions, but also restructuring transactions and transactions in which
the interested shareholder, or its associates or affiliates, receive financial
assistance or tax advantages from the public corporation. Business combinations
must be approved by a majority of the members of a committee of disinterested
directors in advance of the interested person becoming an interested person or
the consummation of the business combination must be delayed for three years and
the price to be paid must meet certain fair price criteria. The committee must
consider the long term interests of the public corporation in connection with
approving any such transaction. Additional restrictions are applicable to
acquisitions of control of 20% or more of a public corporation's voting stock.
 
     Under California law, if a tender offer or a written proposal for approval
of a reorganization of a corporation or a sale of substantially all of its
assets is made by an "interested party", an affirmative opinion in writing as to
the fairness of the consideration to be received by the shareholders must be
delivered to each shareholder. The term "interested party" means a person who is
a party to the transaction and who (a) directly or indirectly controls the
corporation that is the subject of the tender offer or proposal, (b) is, or is
directly or indirectly controlled by, an officer or director of the corporation,
or (c) is an entity in which a material financial interest is held by any
director or executive officer.
 
     No public utility or any of its affiliates may acquire any of the capital
stock of a public utility organized under California law, without CPUC approval,
if (a) the acquiror transacts business in California, or (b) the CPUC determines
that CPUC approval is otherwise required by the public interest. In addition, a
change in control application must be filed with the CPUC in connection with any
change in control of a public utility organized under California law. PSCN
approval is also required prior to any proposed transfer of 15% or more of the
common stock of a public utility doing business in Nevada.
 
     No person may acquire 5% or more of the voting stock of a gas utility
(other than by merger), without Securities and Exchange Commission (the
"Commission") approval, if such person owns 5% or more of the stock of another
public utility or public utility holding company. A registered public utility
holding company may not acquire any security of another gas utility without
Commission approval, unless the transaction is exempt under the Public Utility
Holding Company Act of 1935, as amended (the "PUHCA"), or the regulations
promulgated thereunder. A person becomes a holding company required to be
registered under PUHCA upon acquisition of 10% or more of the voting stock of a
gas utility, unless the Commission determines that the person does not control
the gas utility. The Commission may condition any such
 
                                       24
<PAGE>   27
 
determination upon the applicant refraining from exercising voting rights,
controlling proxies or designating officers or directors. The Commission may not
approve the acquisition of securities of a gas utility unless it determines that
the acquisition would tend toward the economical and efficient development of an
integrated public utility system and would not be detrimental to investor
interests. The Commission may also condition its approval of the acquisition of
the securities of a gas utility upon a fair offer being made for the other
securities of the utility.
 
     In addition to being a gas utility, the Company is also a savings and loan
holding company. No person may acquire control of a savings and loan holding
company without the prior approval of the OTS, unless the transaction is exempt.
A person is conclusively deemed to have obtained control of a savings and loan
holding company if it (a) has acquired any combination of voting stock and
irrevocable proxies representing more than 25% of any class of voting stock of
the savings and loan holding company, or (b) controls in any manner the election
of a majority of the directors of the savings and loan holding company or
savings and loan association. A person who has acquired more than 10% of any
class of voting stock of the savings and loan holding company may also be deemed
to have control of the savings and loan holding company if certain control
factors are present.
 
                              PLAN OF DISTRIBUTION
 
     The Company may sell the Securities to one or more underwriters for public
offering and sale by them or may sell the Securities to investors directly or
through agents. Any such underwriter or agent involved in the offer and sale of
Securities will be named in the applicable Prospectus Supplement. The Company
has reserved the right to sell Securities directly to investors on its own
behalf in those jurisdictions where and in such manner as it is authorized to do
so.
 
   
     Underwriters may offer and sell Securities at a fixed price or prices,
which may be changed, at market prices prevailing at the time of sale, at prices
related to such prevailing market prices or at negotiated prices. The Company
also may, from time to time, authorize dealers, acting as the Company's agents,
to offer and sell Securities upon the terms and conditions as are set forth in
the applicable Prospectus Supplement. In connection with the sale of Securities,
underwriters may receive compensation from the Company in the form of
underwriting discounts or commissions and may also receive commissions from
purchasers of the Securities for whom they may act as agent. Underwriters may
sell Securities to or through dealers, and such dealers may receive compensation
in the form of discounts, concessions or commissions from the underwriters
and/or commissions from the purchasers for whom they may act as agent.
    
 
     Any underwriting compensation paid by the Company to underwriters or agents
in connection with the offering of Securities, and any discounts, concessions or
commissions allowed by underwriters to participating dealers, will be set forth
in the applicable Prospectus Supplement. Dealers and agents participating in the
distribution of Securities may be deemed to be underwriters, and any discounts
and commissions received by them and any profit realized by them on resale of
the Securities may be deemed to be underwriting discounts and commissions.
Underwriters, dealers and agents may be entitled, under agreements entered into
with the Company, to indemnification against and contribution toward certain
civil liabilities.
 
     Securities may also be offered and sold, if so indicated in the Prospectus
Supplement, in connection with a remarketing upon their purchase, in accordance
with a redemption or repayment pursuant to their terms, or otherwise, by one or
more firms ("remarketing firms"), acting as principals for their own accounts or
as agents for the Company. Any remarketing firm will be identified and the terms
of its agreement, if any, with the Company and its compensation will be
described in the applicable Prospectus Supplement. Remarketing firms may be
deemed to be underwriters in connection with the Securities remarketed thereby.
Remarketing firms may be entitled under agreements which may be entered into
with the Company to indemnification by the Company against certain liabilities,
including liabilities under the Securities Act of 1933, and may be customers of,
engage in transactions with or perform services for the Company in the ordinary
course of business.
 
                                       25
<PAGE>   28
 
                                 LEGAL MATTERS
 
     The validity of the Offered Securities will be passed upon for the Company
by O'Melveny & Myers.
 
                                    EXPERTS
 
     The consolidated financial statements incorporated by reference in this
Prospectus have been audited by Arthur Andersen LLP, independent public
accountants, as indicated in their report included in the Annual Report on Form
10-K for the year ended December 31, 1994, and are included herein in reliance
upon the authority of said firm as experts in accounting and auditing in giving
said report.
 
                                       26
<PAGE>   29
 
- ------------------------------------------------------
- ------------------------------------------------------
 
  NO DEALER, SALESPERSON OR OTHER INDIVIDUAL HAS BEEN AUTHORIZED TO GIVE ANY
INFORMATION OR TO MAKE ANY REPRESENTATIONS OTHER THAN THOSE CONTAINED OR
INCORPORATED BY REFERENCE IN THIS PROSPECTUS IN CONNECTION WITH THE OFFER MADE
BY THIS PROSPECTUS AND, IF GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATIONS
MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED BY THE COMPANY OR ANY AGENT,
DEALER OR UNDERWRITER. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY SALE MADE
HEREUNDER SHALL UNDER ANY CIRCUMSTANCES CREATE AN IMPLICATION THAT THERE HAS
BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY SINCE THE DATE HEREOF. THIS
PROSPECTUS DOES NOT CONSTITUTE AN OFFER OR SOLICITATION BY ANYONE IN ANY STATE
IN WHICH SUCH OFFER OR SOLICITATION IS NOT AUTHORIZED OR IN WHICH THE PERSON
MAKING SUCH OFFER OR SOLICITATION IS NOT QUALIFIED TO DO SO OR TO ANYONE TO WHOM
IT IS UNLAWFUL TO MAKE SUCH OFFER OR SOLICITATION.
                            ------------------------
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                        PAGE
                                        ----
<S>                                     <C>
Prospectus
Available Information.................    2
Incorporation of Certain Documents by
  Reference...........................    2
The Company...........................    3
The Trust.............................    3
Use of Proceeds.......................    4
Ratios of Earnings to Fixed Charges...    5
Description of Debt Securities........    5
Particular Terms of Subordinated Debt
  Securities Issued in Connection with
  Preferred Securities................   11
Description of the Preferred
  Securities..........................   12
Description of the Guarantee..........   13
Description of Preferred Stock........   15
Description of Depositary Shares......   19
Description of Common Stock...........   22
Plan of Distribution..................   25
Legal Matters.........................   26
Experts...............................   26
- --------------------------------------------
- --------------------------------------------
</TABLE>
 
- ------------------------------------------------------
- ------------------------------------------------------
 
                                  $270,400,000
 
                                     LOGO(R)
 
                                 SOUTHWEST GAS
                                  CORPORATION
 
                                   SECURITIES
                              --------------------
 
                                   PROSPECTUS
                              --------------------
- ------------------------------------------------------
- ------------------------------------------------------
 
                                 
<PAGE>   30
 
                                    PART II
 
                   INFORMATION NOT REQUIRED IN THE PROSPECTUS
 
ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.*
 
<TABLE>
        <S>                                                                <C>
        Registration fee.................................................  $   93,243
        Rating agency fees...............................................     160,000
        Printing and engraving expenses..................................     220,000
        Accounting fees and expenses.....................................     350,000
        Legal fees and expenses..........................................     600,000
        Blue sky fees and expenses.......................................      20,000
        Fees and expenses of Transfer Agent, Trustee and Depositary......      30,000
        Listing Fees.....................................................      80,000
        Miscellaneous....................................................      25,000
                                                                              -------
               Total.....................................................  $1,578,243
                                                                              =======
</TABLE>
 
- ---------------
 
* Expenses are estimated except for the registration fee.
 
ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
     Section 317 of the General Corporation Law of California provides that a
corporation has the power, and in some cases is required, to indemnify an agent,
including a director or officer, who was or is a party or is threatened to be
made a party to any proceeding, against certain expenses, judgments, fines,
settlements and other amounts under certain circumstances. Article VIII of the
Company's Bylaws provides for the indemnification of directors, officers and
agents as allowed by statute. In addition, the Company has purchased directors
and officers insurance policies which provide insurance against certain
liabilities for directors and officers of the Company and the Regular Trustees.
 
     The Declaration of the Trust provides that no Trustee, affiliate of any
Trustee, or any officers, directors, shareholders, members, partners, employees,
representatives or agents of any Trustee, or any employee or agent of the Trust
or its affiliates (each an "Indemnified Person") shall be liable, responsible or
accountable in damages or otherwise to the Trust or any employee or agent of the
Trust or its affiliates for any loss, damage or claim incurred by reason of any
act or omission performed or omitted by such Indemnified Person in good faith on
behalf of the Trust and in a manner such Indemnified Person reasonably believed
to be within the scope of the authority conferred on such Indemnified Person by
the Declaration or by law, except that an Indemnified Person shall be liable for
any such loss, damage or claim incurred by reason of such Indemnified Person's
gross negligence (or, in the case of the Property Trustee, negligence) or
willful misconduct with respect to such acts or omissions. The Declaration of
the Trust also provides that to the fullest extent permitted by applicable law,
the Company shall indemnify and hold harmless each Indemnified Person from and
against any loss, damage or claim incurred by such Indemnified Person by reason
of any act or omission performed or omitted by such Indemnified Person in good
faith on behalf of the Trust and in a manner such Indemnified Person reasonably
believed to be within the scope of authority conferred on such Indemnified
Person by such Declaration, except that no Indemnified Person shall be entitled
to be indemnified in respect of any loss, damage or claim incurred by such
Indemnified Person by reason of gross negligence (or, in the case of the
Property Trustee, negligence) or willful misconduct with respect to such acts or
omissions. The Declaration of the Trust further provides that, to the fullest
extent permitted by applicable law, expenses (including legal fees) incurred by
an Indemnified Person in defending any claim, demand, action, suit or proceeding
shall, from time to time, be advanced by the Trust prior to the final
disposition of such claim, demand, action, suit or proceeding upon receipt by or
an undertaking by or on behalf of the Indemnified Person to repay such amount if
it shall be determined that the Indemnified Person is not entitled to be
indemnified for the underlying cause of action as authorized by the Declaration.
 
                                      II-1
<PAGE>   31
 
ITEM 16. EXHIBITS.
 
   
<TABLE>
<CAPTION>
        EXHIBIT
        NUMBER                               DESCRIPTION OF EXHIBIT
        -------     -------------------------------------------------------------------------
        <C>         <S>
          *1.01     Forms of Underwriting Agreement.
           3.01     Restated Articles of Incorporation of the Company (included as an exhibit
                    to the Company's Registration Statement No. 2-92938 on Form S-2 and
                    incorporated herein by reference).
           4.01     Form of Guarantee with respect to Preferred Securities.
           4.02     Form of Deposit Agreement (included as an exhibit to the Registrant's
                    Registration Statement No. 33-55621 on Form S-3 and incorporated herein
                    by reference).
           4.03     Form of Depositary Receipt (attached as Exhibit A to Deposit Agreement
                    included as Exhibit 4.02 hereto).
           4.04     Form of Indenture relating to the Senior Debt Securities (included as an
                    exhibit to the Registrant's Registration Statement No. 33-55621 on Form
                    S-3 and incorporated herein by reference).
         **4.05     Certificate of Trust of Southwest Gas Capital I.
           4.06     Form of Amended and Restated Declaration of Trust of Southwest Gas
                    Capital I.
         **4.07     Form of Indenture relating to the Subordinated Debt Securities.
         **4.08     Form of Supplemental Indenture to be used in connection with the issuance
                    of Subordinated Debt Securities and Preferred Securities.
           4.09     Form of Preferred Security (attached as Annex I to Exhibit A to the
                    Amended and Restated Declaration of Trust of Southwest Gas Capital I
                    included as Exhibit 4.06 hereto).
         **4.10     Form of Subordinated Debt Security (included in the Form of Supplemental
                    Indenture included as Exhibit 4.08 hereto).
           5.1      Opinion of O'Melveny & Myers as to the validity of Securities issued by
                    the Company.
           5.2      Opinion of Skadden, Arps, Slate, Meagher & Flom as to the validity of
                    Securities issued by Southwest Gas Capital I.
          *8.01     Opinion of O'Melveny & Myers as to certain federal taxation matters.
        **12.01     Computation of Ratios of Earnings to Fixed Charges of the Company.
          23.01     Consent of Arthur Andersen LLP.
          23.02     Consent of O'Melveny & Myers (included in Exhibit 5.1).
         *23.03     Consent of O'Melveny & Myers (included in Exhibit 8.01).
          23.04     Consent of Skadden, Arps, Slate, Meagher & Flom (included in Exhibit
                    5.2).
        **24.01     Power of Attorney (included on page II-5).
         *25.01     Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939
                    of           under the Indenture relating to the Senior Debt Securities.
        **25.02     Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939
                    of Harris Trust and Savings Bank under the Indenture relating to the
                    Subordinated Debt Securities.
        **25.03     Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939
                    of Harris Trust and Savings Bank under the Amended and Restated
                    Declaration of Trust of Southwest Gas Capital I.
        **25.04     Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939
                    of Harris Trust and Savings Bank under the Guarantee for the benefit of
                    the holders of Preferred Securities.
          99.01     Form of Prospectus Supplement for Preferred Securities.
</TABLE>
    
 
- ---------------
 
 * To be filed by amendment or pursuant to a Form 8-K.
 
   
** Previously filed.
    
 
                                      II-2
<PAGE>   32
 
ITEM 17. UNDERTAKINGS.
 
     Each of the undersigned Registrants 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, unless the information required to be included
        in such post-effective amendment is contained in a periodic report filed
        by Registrant pursuant to Section 13 or Section 15(d) of the Securities
        Exchange Act of 1934 and incorporated herein by reference;
 
             (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, unless the information required to be
        included in such post-effective amendment is contained in a period
        report filed by each Registrant pursuant to Section 13 or Section 15(d)
        of the Securities Act of 1934 and incorporated herein by reference.
        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 percent change in the maximum aggregate offering price
        set forth in the "Calculation of Registration Fee" table in the
        effective registration statement;
 
             (iii) To include any material information with respect to the plan
        of distribution not previously disclosed in the Registration Statement
        or any material change to such information in the Registration
        Statement;
 
          (2) That, for the purpose of determining any liability under the
     Securities Act of 1933, each such post-effective amendment shall be deemed
     to be a new registration statement relating to the securities offered
     therein, and the offering of such securities at that time shall be deemed
     to be the initial bona fide offering thereof;
 
          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.
 
          (4) That, for purposes of determining any liability under the
     Securities Act of 1933, each filing of a Registrant's annual report
     pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act
     of 1934 that is incorporated by reference in the Registration Statement
     shall be deemed to be a new Registration Statement relating to the
     securities offered therein, and the offering of such securities at that
     time shall be deemed to be the initial bona fide offering thereof.
 
          (5) To provide to the underwriter at the closing specified in the
     underwriting agreements, certificates in such denominations and registered
     in such names as required by the underwriter to permit prompt delivery to
     each purchaser.
 
          (6) That, for the purposes of determining any liability under the
     Securities Act of 1933:
 
             (i) The information omitted from the form of prospectus filed as
        part of this Registration Statement in reliance upon Rule 430A and
        contained in the form of prospectus filed by the Registrant pursuant to
        Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed
        to be part of this Registration Statement as of the time it was declared
        effective.
 
             (ii) Each post-effective amendment that contains a form of
        prospectus 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>   33
 
     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of each
Registrant pursuant to the provisions described in Item 15 above, or otherwise,
each Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act of 1933 and is, therefore, unenforceable. In the event
that a claim for indemnification against such liabilities (other than the
payment by each Registrant of expenses incurred or paid by a director, officer
or controlling person of each Registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered, each Registrant will,
unless in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question of whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933 and will be governed by the final adjudication of such
issue.
 
     The Company hereby undertakes to file an application for the purpose of
determining the eligibility of the trustee under the Indenture relating to the
Senior Debt Securities to act under subsection (a) of Section 310 of the Trust
Indenture Act in accordance with the rules and regulations prescribed by the
Commission under Section 305(b)(2) of the Trust Indenture Act.
 
                                      II-4
<PAGE>   34
 
                                   SIGNATURES
 
   
     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Amendment No. 1 to
the Registration Statement (No. 33-62143) to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Las Vegas, State of
Nevada, on the 6th day of October, 1995.
    
 
                                          SOUTHWEST GAS CORPORATION
 
                                          By     /s/  MICHAEL O. MAFFIE
                                             ---------------------------------
                                                     Michael O. Maffie
                                               President and Chief Executive
                                                           Officer
 
   
     Pursuant to the requirements of the Securities Act of 1933, this Amendment
No. 1 to the Registration Statement (No. 33-62143) has been signed by the
following persons in the capacities indicated as of the 6th day of October,
1995.
    
 
   
<TABLE>
<CAPTION>
                   SIGNATURE                                TITLE
- -----------------------------------------------  ----------------------------
<S>                                              <C>                 
            /s/  MICHAEL O. MAFFIE                 Director, President and
     ---------------------------------------       Chief Executive Officer
              (Michael O. Maffie)                    (Principal Executive
                                                           Officer)
                                                           
             /s/  GEORGE C. BIEHL                 Senior Vice President and
     ---------------------------------------       Chief Financial Officer
               (George C. Biehl)                     (Principal Financial
                                                           Officer)
                                                           
             /s/  EDWARD A. JANOV                    Controller and Chief
     ---------------------------------------          Accounting Officer
               (Edward A. Janov)                    (Principal Accounting  
                                                           Officer)
                                                           
                      *                                    Director
     ---------------------------------------
             (Ralph C. Batastini)

                      *                                    Director
     ---------------------------------------
              (Manuel J. Cortez)

                      *                                    Director
     ---------------------------------------
                (Lloyd T. Dyer)

                      *                             Chairman of the Board
     ---------------------------------------             of Directors
               (Kenny C. Guinn)                          
                           
                      *                                    Director
     ---------------------------------------
              (Thomas Y. Hartley)

                      *                                    Director
     ---------------------------------------
              (Michael B. Jager)
</TABLE>
    
 
                                      II-5
<PAGE>   35
 
   
<TABLE>
<CAPTION>
                   SIGNATURE                                TITLE
- -----------------------------------------------  ----------------------------
<S>                                              <C>             
                      *                                    Director
     ---------------------------------------
               (Leonard R. Judd)

                      *                                    Director
     ---------------------------------------
             (James R. Lincicome)

                      *                                    Director
     ---------------------------------------
              (Carolyn M. Sparks)

                      *                                    Director
     ---------------------------------------
               (Robert S. Sundt)

    *By      /s/  GEORGE C. BIEHL
        ------------------------------------
                George C. Biehl
               Attorney-in-fact
</TABLE>
    
 
   
     Pursuant to the requirements of the Securities Act of 1933, Southwest Gas
Capital I certifies that it has reasonable grounds to believe that it meets all
the requirements for filing on Form S-3 and has duly caused this Amendment No. 1
to the Registration Statement (No. 33-62143) to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Las Vegas, State of
Nevada, on the 6th day of October, 1995.
    
 
                                          SOUTHWEST GAS CAPITAL I
 
                                          By:      /s/  GEORGE C. BIEHL
                                              --------------------------------
                                                  George C. Biehl, Trustee
 
                                          By:      /s/  JEFFREY W. SHAW
                                              --------------------------------
                                                  Jeffrey W. Shaw, Trustee
 
                                      II-6
<PAGE>   36
 
                                 EXHIBIT INDEX
   
<TABLE>
<CAPTION>
EXHIBIT
NUMBER                                   DESCRIPTION OF EXHIBIT
- -------     ---------------------------------------------------------------------------------
<C>         <S>
   4.01     Form of Guarantee with respect to Preferred Securities
   4.06     Form of Amended and Restated Declaration of Trust of Southwest Gas Capital I
   4.09     Form of Preferred Security (attached as Annex I to Exhibit A to the Amended and
            Restated Declaration of Trust of Southwest Gas Capital I included as Exhibit 4.06
            hereto).
   5.1      Opinion of O'Melveny & Myers as to the validity of Securities issued by the
            Company.
   5.2      Opinion of Skadden, Arps, Slate, Meagher & Flom as to the validity of Securities
            issued by Southwest Gas Capital I.
  23.01     Consent of Arthur Andersen LLP
  23.02     Consent of O'Melveny & Myers (included in Exhibit 5.1).
  23.04     Consent of Skadden, Arps, Slate, Meagher & Flom (included in Exhibit 5.2).
  99.01     Form of Prospectus Supplement for Preferred Securities
</TABLE>
    

<PAGE>   1
================================================================================


                    PREFERRED SECURITIES GUARANTEE AGREEMENT

                             SOUTHWEST GAS CAPITAL I













                         Dated as of ____________, ____



================================================================================

                                  Exhibit 4.01


<PAGE>   2



                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
Section                                                                               Page
- -------                                                                               ----
                                                ARTICLE I                                   
                                                                                
                                      Definitions and Interpretation                         
                                                                                
<S>                                                                                     <C>
   Section 1.1.    Definitions and Interpretation.  . . . . . . . . . . . . . . . .      2
                                                                                
                                                                                
                                               ARTICLE II                                   
                                                                                
                                           Trust Indenture Act                              
                                                                                
   Section 2.1.    Trust Indenture Act; Application.  . . . . . . . . . . . . . . .      5
   Section 2.2.    Lists of Holders of Trust Securities.  . . . . . . . . . . . . .      5
   Section 2.3.    Reports by the Preferred Guarantee Trustee.  . . . . . . . . . .      6
   Section 2.4.    Periodic Reports to Preferred Guarantee Trustee.   . . . . . . .      6
   Section 2.5.    Evidence of Compliance with Conditions Precedent.  . . . . . . .      6
   Section 2.6.    Events of Default; Waiver.   . . . . . . . . . . . . . . . . . .      6
   Section 2.7.    Event of Default; Notice.  . . . . . . . . . . . . . . . . . . .      7
   Section 2.8.    Conflicting Interests.   . . . . . . . . . . . . . . . . . . . .      7
                                                                                
                                               ARTICLE III                                  
                                                                                
                                       Power, Duties and Rights of                          
                                       Preferred Guarantee Trustee                          
                                                                                
   Section 3.1.    Powers and Duties of the Preferred Guarantee Trustee.  . . . . .      7
   Section 3.2.    Certain Rights of Preferred Guarantee Trustee.   . . . . . . . .     10
   Section 3.3.    Not Responsible for Recitals or Issuance of Guarantee.   . . . .     12
                                                                                
                                                ARTICLE IV                                   
                                                                                
                                        Preferred Guarantee Trustee                          
                                                                                
   Section 4.1.    Preferred Guarantee Trustee; Eligibility.  . . . . . . . . . . .     12
   Section 4.2.    Appointment, Removal and Resignation of Preferred Guarantee 
                                 Trustees . . . . . . . . . . . . . . . . . . . . .     13
                                                                                
                                                                                
                                                ARTICLE V                                   
                                                                                
                                                Guarantee                                   
                                                                                
   Section 5.1.    Guarantee.   . . . . . . . . . . . . . . . . . . . . . . . . . .     14
   Section 5.2.    Subordination.   . . . . . . . . . . . . . . . . . . . . . . . .     14
   Section 5.3.    Waiver of Notice and Demand.   . . . . . . . . . . . . . . . . .     14
</TABLE>                                                                        



                                        i


<PAGE>   3


<TABLE>
<S>                                                                                       <C>
   Section 5.4.    Obligations Not Affected.  . . . . . . . . . . . . . . . . . . . .     15
   Section 5.5.    Rights of Holders.   . . . . . . . . . . . . . . . . . . . . . . .     16
   Section 5.6.    Guarantee of Payment.  . . . . . . . . . . . . . . . . . . . . . .     16
   Section 5.7.    Subrogation.   . . . . . . . . . . . . . . . . . . . . . . . . . .     16
   Section 5.8.    Independent Obligations.   . . . . . . . . . . . . . . . . . . . .     17
                                                                                  
                                                ARTICLE VI
                                                                                  
                                Limitation of Transactions; Subordination
                                                                                  
   Section 6.1.    Limitation of Transactions.  . . . . . . . . . . . . . . . . . . .     17
   Section 6.2.    Ranking.   . . . . . . . . . . . . . . . . . . . . . . . . . . . .     17
                                                                                  
                                               ARTICLE VII                                    
                                                                                  
                                               Termination                                    
                                                                                  
   Section 7.1.    Termination.   . . . . . . . . . . . . . . . . . . . . . . . . . .     18
                                                                                  
                                              ARTICLE VIII                                    
                                                                                  
                                            Indemnification                                  
                                                                                  
   Section 8.1.    Exculpation.   . . . . . . . . . . . . . . . . . . . . . . . . . .     18
   Section 8.2.    Indemnification.   . . . . . . . . . . . . . . . . . . . . . . . .     19
                                                                                  
                                               ARTICLE IX                                     
                                                                                  
                                              Miscellaneous                                   
                                                                                  
   Section 9.1.    Successors and Assigns.  . . . . . . . . . . . . . . . . . . . . .     19
   Section 9.2.    Amendments.  . . . . . . . . . . . . . . . . . . . . . . . . . . .     19
   Section 9.3.    Notices.   . . . . . . . . . . . . . . . . . . . . . . . . . . . .     20
   Section 9.4.    Benefit.   . . . . . . . . . . . . . . . . . . . . . . . . . . . .     21
   Section 9.5.    Governing Law.   . . . . . . . . . . . . . . . . . . . . . . . . .     21
</TABLE>


                                       ii
<PAGE>   4



                    PREFERRED SECURITIES GUARANTEE AGREEMENT

                 This GUARANTEE AGREEMENT ("Guarantee Agreement"), dated as of
___________, ____, is executed and delivered by Southwest Gas Corporation, a
California corporation (the "Guarantor"), and Harris Trust and Savings Bank, an
Illinois banking corporation, as trustee (the "Preferred Guarantee Trustee"),
for the benefit of the Holders (as defined herein) from time to time of the
Preferred Securities (as defined herein) of Southwest Gas Capital I, a Delaware
statutory business trust (the "Issuer").

                                    RECITALS

                 WHEREAS, pursuant to an Amended and Restated Declaration of
Trust (the "Declaration"), dated as of ____________, ____, among the trustees of
the Issuer named therein, the Guarantor as sponsor and the holders from time to
time of undivided beneficial interests in the assets of the Issuer, the Issuer
is issuing on the date hereof $____________ aggregate stated liquidation amount
of Preferred Securities designated the _____% Trust Originated Preferred
Securities (the "Preferred Securities");

                 WHEREAS, as incentive for the Holders (as hereinafter defined)
to purchase the Preferred Securities, the Guarantor desires irrevocably and
unconditionally to agree, to the extent set forth in this Guarantee Agreement,
to pay to the Holders of the Preferred Securities the Guarantee Payments (as
defined herein) and to make certain other payments on the terms and conditions
set forth herein; and

                 WHEREAS, the Guarantor is also executing and delivering a
guarantee agreement (the "Common Securities Guarantee Agreement") with
substantially identical terms to this Guarantee Agreement for the benefit of the
holders of the Common Securities (as defined herein) except that if an Event of
Default (as defined in the Indenture (as defined herein)), has occurred and is
continuing, the rights of holders of the Common Securities to receive Guarantee
Payments under the Common Securities Guarantee Agreement are subordinated to the
rights of Holders of Preferred Securities to receive Guarantee Payments under
this Guarantee Agreement.

                 NOW, THEREFORE, in consideration of the purchase by each Holder
of Preferred Securities, which purchase the Guarantor hereby agrees shall
benefit the Guarantor, the Guarantor executes and delivers this Guarantee
Agreement for the benefit of the Holders.


                                       1

<PAGE>   5

                                    ARTICLE I

                         Definitions and Interpretation

Section 1.1.     Definitions and Interpretation.

                 In this Guarantee Agreement, unless the context otherwise
requires:

         (a)     Capitalized terms used in this Guarantee Agreement but not
                 defined in the preamble above have the respective meanings
                 assigned to them in this Section 1.1;

         (b)     a term defined anywhere in this Guarantee Agreement has the
                 same meaning throughout;

         (c)     all references to "the Guarantee Agreement" or "this Guarantee
                 Agreement" are to this Guarantee Agreement as modified,
                 supplemented or amended from time to time;

         (d)     all references in this Guarantee Agreement to Articles and
                 Sections are to Articles and Sections of this Guarantee
                 Agreement unless otherwise specified;

         (e)     a term defined in the Trust Indenture Act has the same meaning
                 when used in this Guarantee Agreement unless otherwise defined
                 in this Guarantee Agreement or unless the context otherwise
                 requires; and

         (f)     a reference to the singular includes the plural and vice versa.

                 "Affiliate" has the same meaning as given to that term in Rule
405 of the Securities Act or any successor rule thereunder.

                 "Authorized Officer" of a Person means any Person that is
authorized to bind such Person.

                 "Common Securities" means the common securities representing
undivided beneficial interests in the assets of the Issuer.

                 "Covered Person" means any Holder or beneficial owner of
Preferred Securities.

                 "Direction" by a Person means a written direction signed:

                 (a) if the Person is a natural person by that Person; or

                                        2


<PAGE>   6



                 (b) in any other case, in the name of such Person by one or
         more Authorized Officers of that Person.

                 "Event of Default" means a default by the Guarantor on any of
its payment or other obligations under this Guarantee Agreement.

                 "Guarantee Payments" means the following payments or
distributions, without duplication, with respect to the Preferred Securities, to
the extent not paid or made by the Issuer: (i) any accrued and unpaid
Distributions (as defined in the Declaration) that are required to be paid on
such Preferred Securities to the extent the Issuer shall have received a payment
of interest or principal on the Notes therefor from the Guarantor, (ii) the
redemption price, including all accrued and unpaid Distributions to the date of
redemption (the "Redemption Price") to the extent the Issuer has received a
payment of interest or principal on the Notes from the Guarantor with respect to
any Preferred Securities called for redemption by the Issuer, and (iii) upon a
voluntary or involuntary dissolution, winding-up or termination of the Issuer
(other than in connection with the distribution of Notes to the Holders in
exchange for Preferred Securities as provided in the Declaration or the
redemption of all of the Preferred Securities upon the maturity or redemption of
the Notes), the lesser of (a) the aggregate of the liquidation amount and all
accrued and unpaid Distributions on the Preferred Securities to the date of
payment, and (b) the amount of assets of the Issuer remaining available for
distribution to Holders in liquidation of the Issuer (in either case, the
"Liquidation Distribution").

                 "Holder" shall mean any holder, as registered on the books and
records of the Issuer of any Preferred Securities; provided, that, in
determining whether the holders of the requisite percentage of Preferred
Securities have given any request, notice, consent or waiver hereunder, "Holder"
shall not include the Guarantor or any Affiliate of the Guarantor.

                 "Indemnified Person" means the Preferred Guarantee Trustee, any
Affiliate of the Preferred Guarantee Trustee, or any officers, directors,
shareholders, members, partners, employees, representatives or agents of the
Preferred Guarantee Trustee.

                 "Indenture" means the Indenture dated as of _____________,
____, among the Note Issuer and Harris Trust and Savings Bank, as trustee, and
any indenture supplemental thereto pursuant to which certain Notes are to be
issued.

                 "Majority in liquidation amount of the Trust Securities" means,
except as provided by the Trust Indenture Act, a vote by Holder(s) of Preferred
Securities, voting separately as a class, of more than 50% of the liquidation
amount (including the stated amount that would be paid on redemption,
liquidation

                                        3


<PAGE>   7



or otherwise, plus accrued and unpaid Distributions to the date upon which the
voting percentages are determined) of all Preferred Securities.

                 "Note Issuer" means the Guarantor in its capacity as issuer of
the Notes.

                 "Notes" means the subordinated debt securities of the Note
Issuer issued pursuant to the Indenture and acquired by the Issuer.

                 "Officers' Certificate" means, with respect to any Person, a
certificate signed by two Authorized Officers of such Person. Any Officers'
Certificate delivered with respect to compliance with a condition or covenant
provided for in this Guarantee Agreement shall include:

         (a)     a statement that each officer signing the Officers' Certificate
                 has read the covenant or condition and the definition relating
                 thereto;

         (b)     a brief statement of the nature and scope of the examination or
                 investigation undertaken by each officer in rendering the
                 Officers' Certificate;

         (c)     a statement that each such officer has made such examination or
                 investigation as, in such officer's opinion, is necessary to
                 enable such officer to express an informed opinion as to
                 whether or not such covenant or condition has been complied
                 with; and

         (d)     a statement as to whether, in the opinion of each such officer,
                 such condition or covenant has been complied with.

                 "Person" means a legal person, including any individual,
corporation, estate, partnership, joint venture, association, joint stock
company, limited liability company, trust, unincorporated association, or
government or any agency or political subdivision thereof, or any other entity
of whatever nature.

                 "Preferred Guarantee Trustee" means Harris Trust and Savings
Bank, until a Successor Preferred Guarantee Trustee has been appointed and has
accepted such appointment pursuant to the terms of this Guarantee Agreement, and
thereafter means each such Successor Preferred Guarantee Trustee.

                 "Responsible Officer" means, when used with respect to the
Preferred Guarantee Trustee, an officer of the Trustee in the Corporate Trust
Office, including the president, any vice-president, any assistant
vice-president, the secretary, any assistant secretary, the treasurer, any
assistant treasurer, any

                                        4


<PAGE>   8



trust officer or assistant trust officer or any other officer customarily
performing functions similar to those performed by any of the above designated
officers and also means, with respect to a particular corporate trust matter,
any other officer to whom such matter is referred because of that officer's
knowledge of and familiarity with the particular subject.

                 "Securities Act" means the Securities Act of 1933, as amended
from time to time, or any successor legislation.

                 "Successor Preferred Guarantee Trustee" means a successor
Preferred Guarantee Trustee possessing the qualifications to act as Preferred
Guarantee Trustee under Section 4.1.

                 "Trust Indenture Act" means the Trust Indenture Act of 1939, in
effect at the date as of which this instrument was executed; provided, however,
that in the event the Trust Indenture Act of 1939 is amended after such date,
"Trust Indenture Act" means to the extent required by any such amendment, the
Trust Indenture Act of 1939 as so amended.

                 "Trust Securities" means collectively the Common Securities and
the Preferred Securities.

                                   ARTICLE II

                               Trust Indenture Act

Section 2.1.     Trust Indenture Act; Application.

         (a)     This Guarantee Agreement is subject to the provisions of the
                 Trust Indenture Act that are required to be part of this
                 Guarantee Agreement and shall, to the extent applicable, be
                 governed by such provisions; and

         (b)     if and to the extent that any provision of this Guarantee
                 Agreement limits, qualifies or conflicts with the duties
                 imposed by Sections 310 to 317, inclusive, of the Trust
                 Indenture Act, such duties imposed by the Trust Indenture Act
                 shall control.

Section 2.2.     Lists of Holders of Trust Securities.

         (a)     The Guarantor shall provide the Preferred Guarantee Trustee
                 with a list, in such form as the Preferred Guarantee Trustee
                 may reasonably require, of the names and addresses of the
                 Holders of the Preferred Securities ("List of Holders") as of
                 such date, (i) within 14 days after _________ and _______ of
                 each

                                        5


<PAGE>   9



                 year, and (ii) at any other time within 30 days of receipt by
                 the Guarantor of a written request for a List of Holders as of
                 a date no more than 14 days before such List of Holders is
                 given to the Preferred Guarantee Trustee provided that the
                 Guarantor shall not be obligated to provide such List of
                 Holders at any time the List of Holders does not differ from
                 the most recent List of Holders given to the Preferred
                 Guarantee Trustee by the Guarantor. The Preferred Guarantee
                 Trustee may destroy any List of Holders previously given to it
                 on receipt of a new List of Holders.

         (b)     The Preferred Guarantee Trustee shall comply with its
                 obligations under Sections 311(a), 311(b) and 312(b) of the
                 Trust Indenture Act.


Section 2.3.     Reports by the Preferred Guarantee Trustee.

                 Within 60 days after ____________ of each year, the Preferred
Guarantee Trustee shall provide to the Holders of the Preferred Securities such
reports as are required by Section 313 of the Trust Indenture Act, if any, in
the form and in the manner provided by Section 313 of the Trust Indenture Act.
The Preferred Guarantee Trustee shall also comply with the requirements of
Section 313(d) of the Trust Indenture Act.

Section 2.4.     Periodic Reports to Preferred Guarantee Trustee.

                 The Guarantor shall provide to the Preferred Guarantee Trustee
such documents, reports and information as required by Section 314 (if any) and
the compliance certificate required by Section 314 of the Trust Indenture Act in
the form, in the manner and at the times required by Section 314 of the Trust
Indenture Act.

Section 2.5.     Evidence of Compliance with Conditions Precedent.

                 The Guarantor shall provide to the Preferred Guarantee Trustee
such evidence of compliance with any conditions precedent, if any, provided for
in this Guarantee Agreement that relate to any of the matters set forth in
Section 314(c) of the Trust Indenture Act. Any certificate or opinion required
to be given by an officer pursuant to Section 314(c)(1) may be given in the form
of an Officers' Certificate.

Section 2.6.     Events of Default; Waiver.

                 The Holders of a Majority in liquidation amount of Preferred
Securities may, by vote, on behalf of the Holders of

                                        6


<PAGE>   10

all of the Preferred Securities, waive any past Event of Default and its
consequences. Upon such waiver, any such Event of Default shall cease to exist,
and any Event of Default arising therefrom shall be deemed to have been cured,
for every purpose of this Guarantee Agreement, but no such waiver shall extend
to any subsequent or other default or Event of Default or impair any right
consequent thereon.

Section 2.7.     Event of Default; Notice.

         (a) The Preferred Guarantee Trustee shall, within 90 days after the
occurrence of an Event of Default, transmit by mail, first class postage
prepaid, to the Holders of the Preferred Securities, notices of all Events of
Default known to the Preferred Guarantee Trustee, unless such defaults have been
cured before the giving of such notice, provided, that, the Preferred Guarantee
Trustee shall be protected in withholding such notice if and so long as the
board of directors, the executive committee, or a trust committee of directors
and/or Responsible Officers of the Preferred Guarantee Trustee in good faith
determines that the withholding of such notice is in the interests of the
Holders of the Preferred Securities.

         (b) The Preferred Guarantee Trustee shall not be deemed to have
knowledge of any Event of Default unless the Preferred Guarantee Trustee shall
have received written notice as provided in Section 9.3, or a Responsible
Officer shall have obtained actual notice, of such Event of Default.

Section 2.8.     Conflicting Interests.

                 The Declaration shall be deemed to be specifically described in
this Guarantee Agreement for the purposes of the first proviso contained in
Section 310(b) of the Trust Indenture Act.

                                   ARTICLE III

                           Power, Duties and Rights of
                           Preferred Guarantee Trustee

Section 3.1.     Powers and Duties of the Preferred Guarantee Trustee.

         (a)     This Guarantee Agreement shall be held by the Preferred
                 Guarantee Trustee for the benefit of the Holders of the
                 Preferred Securities, and the Preferred Guarantee Trustee shall
                 not transfer this Guarantee Agreement to any Person except a
                 Holder of Preferred Securities exercising his or her rights
                 pursuant to Section 5.5(b)

                                        7


<PAGE>   11



                 or to a Successor Preferred Guarantee Trustee on acceptance by
                 such Successor Preferred Guarantee Trustee of its appointment
                 to act as Successor Preferred Guarantee Trustee. The right,
                 title and interest of the Preferred Guarantee Trustee shall
                 automatically vest in any Successor Preferred Guarantee
                 Trustee, and such vesting and cessation of title shall be
                 effective whether or not conveyancing documents have been
                 executed and delivered pursuant to the appointment of such
                 Successor Preferred Guarantee Trustee.

         (b)     If an Event of Default has occurred and is continuing, the
                 Preferred Guarantee Trustee shall enforce this Guarantee
                 Agreement for the benefit of the Holders of the Preferred
                 Securities.

         (c)     The Preferred Guarantee Trustee, before the occurrence of any
                 Event of Default and after the curing of all Events of Default
                 that may have occurred, shall undertake to perform only such
                 duties as are specifically set forth in this Guarantee
                 Agreement, and no implied covenants shall be read into this
                 Guarantee Agreement against the Preferred Guarantee Trustee. In
                 case an Event of Default has occurred (that has not been cured
                 or waived pursuant to Section 2.6), the Preferred Guarantee
                 Trustee shall exercise such of the rights and powers vested in
                 it by this Guarantee Agreement, and use the same degree of care
                 and skill in its exercise thereof, as a prudent person would
                 exercise or use under the circumstances in the conduct of his
                 or her own affairs.

         (d)     No provision of this Guarantee Agreement shall be construed to
                 relieve the Preferred Guarantee Trustee from liability for its
                 own negligent action, its own negligent failure to act, or its
                 own willful misconduct, except that:

                 (i)      prior to the occurrence of any Event of Default and
                          after the curing or waiving of all such Events of
                          Default that may have occurred:

                          (A)     the duties and obligations of the Preferred
                                  Guarantee Trustee shall be determined solely
                                  by the express provisions of this Guarantee
                                  Agreement, and the Preferred Guarantee Trustee
                                  shall not be liable except for the performance
                                  of such duties and obligations as are
                                  specifically set forth in this Guarantee
                                  Agreement, and no implied covenants or
                                  obligations shall be read into this Guarantee
                                  Agreement against the Preferred Guarantee
                                  Trustee; and

                                        8


<PAGE>   12




                          (B)     in the absence of bad faith on the part of the
                                  Preferred Guarantee Trustee, the Preferred
                                  Guarantee Trustee may conclusively rely, as to
                                  the truth of the statements and the
                                  correctness of the opinions expressed therein,
                                  upon any certificates or opinions furnished to
                                  the Preferred Guarantee Trustee and conforming
                                  to the requirements of this Guarantee
                                  Agreement; but in the case of any such
                                  certificates or opinions that by any provision
                                  hereof are specifically required to be
                                  furnished to the Preferred Guarantee Trustee,
                                  the Preferred Guarantee Trustee shall be under
                                  a duty to examine the same to determine
                                  whether or not they conform to the
                                  requirements of this Guarantee Agreement;

                 (ii)     the Preferred Guarantee Trustee shall not be liable
                          for any error of judgment made in good faith by a
                          Responsible Officer of the Preferred Guarantee
                          Trustee, unless it shall be proved that the Preferred
                          Guarantee Trustee was negligent in ascertaining the
                          pertinent facts upon which such judgment was made;

                 (iii)    the Preferred Guarantee Trustee shall not be liable
                          with respect to any action taken or omitted to be
                          taken by it in good faith in accordance with the
                          direction of the Holders of not less than a Majority
                          in liquidation amount of the Preferred Securities
                          relating to the time, method and place of conducting
                          any proceeding for any remedy available to the
                          Preferred Guarantee Trustee, or exercising any trust
                          or power conferred upon the Preferred Guarantee
                          Trustee under this Guarantee Agreement; and

                 (iv)     no provision of this Guarantee Agreement shall require
                          the Preferred Guarantee Trustee to expend or risk its
                          own funds or otherwise incur personal financial
                          liability in the performance of any of its duties or
                          in the exercise of any of its rights or powers, if the
                          Preferred Guarantee Trustee shall have reasonable
                          grounds for believing that the repayment of such funds
                          or liability is not reasonably assured to it under the
                          terms of this Guarantee Agreement or adequate
                          indemnity against such risk or liability is not
                          reasonably assured to it.

                                        9


<PAGE>   13



Section 3.2.     Certain Rights of Preferred Guarantee Trustee.

         (a)     Subject to the provisions of Section 3.1:

                 (i)      The Preferred Guarantee Trustee may rely and shall be
                          fully protected in acting or refraining from acting
                          upon any resolution, certificate, statement,
                          instrument, opinion, report, notice, request,
                          direction, consent, order, bond, debenture, note,
                          other evidence of indebtedness or other paper or
                          document believed by it to be genuine and to have been
                          signed, sent or presented by the proper party or
                          parties.

                 (ii)     Any direction or act of the Guarantor contemplated by
                          this Guarantee Agreement shall be sufficiently
                          evidenced by a Direction or an Officers' Certificate.

                 (iii)    Whenever, in the administration of this Guarantee
                          Agreement, the Preferred Guarantee Trustee shall deem
                          it desirable that a matter be proved or established
                          before taking, suffering or omitting any action
                          hereunder, the Preferred Guarantee Trustee (unless
                          other evidence is herein specifically prescribed) may,
                          in the absence of bad faith on its part, request and
                          rely upon an Officers' Certificate which, upon receipt
                          of such request, shall be promptly delivered by the
                          Guarantor.

                 (iv)     The Preferred Guarantee Trustee shall have no duty to
                          see to any recording, filing or registration of any
                          instrument (or any rerecording, refiling or
                          registration thereof).

                 (v)      The Preferred Guarantee Trustee may consult with
                          counsel, and the written advice or opinion of such
                          counsel with respect to legal matters shall be full
                          and complete authorization and protection in respect
                          of any action taken, suffered or omitted by it
                          hereunder in good faith and in accordance with such
                          advice or opinion. Such counsel may be counsel to the
                          Guarantor or any of its Affiliates and may include any
                          of its employees. The Preferred Guarantee Trustee
                          shall have the right at any time to seek instructions
                          concerning the administration of this Guarantee
                          Agreement from any court of competent jurisdiction.

                                       10


<PAGE>   14



                 (vi)     The Preferred Guarantee Trustee shall be under no
                          obligation to exercise any of the rights or powers
                          vested in it by this Guarantee Agreement at the
                          request or direction of any Holder, unless such Holder
                          shall have provided to the Preferred Guarantee Trustee
                          such security and indemnity acceptable to the
                          Preferred Guarantee Trustee, against the costs,
                          expenses (including attorneys' fees and expenses) and
                          liabilities that might be incurred by it in complying
                          with such request or direction, including such
                          reasonable advances as may be requested by the
                          Preferred Guarantee Trustee; provided that, nothing
                          contained in this Section 3.2(a)(vi) shall be taken to
                          relieve the Preferred Guarantee Trustee, upon the
                          occurrence of an Event of Default, of its obligation
                          to exercise the rights and powers vested in it by this
                          Guarantee Agreement.

                 (vii)    The Preferred Guarantee Trustee shall not be bound to
                          make any investigation into the facts or matters
                          stated in any resolution, certificate, statement,
                          instrument, opinion, report, notice, request,
                          direction, consent, order, bond, debenture, note,
                          other evidence of indebtedness or other paper or
                          document, but the Preferred Guarantee Trustee, in its
                          discretion may make such further inquiry or
                          investigation into such facts or matters as it may see
                          fit.

                 (viii)   The Preferred Guarantee Trustee may execute any of the
                          trusts or powers hereunder or perform any duties
                          hereunder either directly or by or through agents or
                          attorneys, and the Preferred Guarantee Trustee shall
                          not be responsible for any misconduct or negligence on
                          the part of any agent or attorney appointed with due
                          care by it hereunder.

                 (ix)     Any action taken by the Preferred Guarantee Trustee or
                          its agents hereunder shall bind the Holders of the
                          Preferred Securities, and the signature of the
                          Preferred Guarantee Trustee or its agents alone shall
                          be sufficient and effective to perform any such
                          action. No third party shall be required to inquire as
                          to the authority of the Preferred Guarantee Trustee to
                          so act or as to its compliance with any of the terms
                          and provisions of this Guarantee Agreement, both of
                          which shall be conclusively evidenced by the Preferred
                          Guarantee Trustee's or its agent's taking such action.

                                       11


<PAGE>   15



                 (x)      Whenever in the administration of this Guarantee
                          Agreement the Preferred Guarantee Trustee shall deem
                          it desirable to receive instructions with respect to
                          enforcing any remedy or right or taking any other
                          action hereunder, the Preferred Guarantee Trustee (i)
                          may request instructions from the Holders of the
                          Preferred Securities, (ii) may refrain from enforcing
                          such remedy or right or taking such other action until
                          such instructions are received, and (iii) shall be
                          protected in acting in accordance with such
                          instructions.

         (b)     No provision of this Guarantee Agreement shall be deemed to
                 impose any duty or obligation on the Preferred Guarantee
                 Trustee to perform any act or acts or exercise any right,
                 power, duty or obligation conferred or imposed on it in any
                 jurisdiction in which it shall be illegal, or in which the
                 Preferred Guarantee Trustee shall be unqualified or incompetent
                 in accordance with applicable law, to perform any such act or
                 acts or to exercise any such right, power, duty or obligation.
                 No permissive power or authority available to the Preferred
                 Guarantee Trustee shall be construed to be a duty.

Section 3.3.     Not Responsible for Recitals or Issuance of Guarantee.

                 The recitals contained in this Guarantee shall be taken as the
statements of the Guarantor, and the Preferred Guarantee Trustee does not assume
any responsibility for their correctness. The Preferred Guarantee Trustee makes
no representation as to the validity or sufficiency of this Guarantee Agreement.

                                   ARTICLE IV

                           Preferred Guarantee Trustee

Section 4.1.     Preferred Guarantee Trustee; Eligibility.

         (a)     There shall at all times be a Preferred Guarantee Trustee which
                 shall:

                 (i)      not be an Affiliate of the Guarantor; and

                 (ii)     be a corporation organized and doing business under
                          the laws of the United States of America or any State
                          or Territory thereof or of the District of Columbia,
                          or a corporation or Person permitted by the Securities
                          and Exchange Commission to act

                                       12


<PAGE>   16

                          as an institutional trustee under the Trust Indenture
                          Act, authorized under such laws to exercise corporate
                          trust powers, having a combined capital and surplus of
                          at least 50 million U.S. dollars ($50,000,000), and
                          subject to supervision or examination by Federal,
                          State, Territorial or District of Columbia authority.
                          If such corporation publishes reports of condition at
                          least annually, pursuant to law or to the requirements
                          of the supervising or examining authority referred to
                          above, then, for the purposes of this Section
                          4.1(a)(ii), the combined capital and surplus of such
                          corporation shall be deemed to be its combined capital
                          and surplus as set forth in its most recent report of
                          condition so published.

         (b)     If at any time the Preferred Guarantee Trustee shall cease to
                 be eligible to so act under Section 4.1(a), the Preferred
                 Guarantee Trustee shall immediately resign in the manner and
                 with the effect set out in Section 4.2(c).

         (c)     If the Preferred Guarantee Trustee has or shall acquire any
                 "conflicting interest" within the meaning of Section 310(b) of
                 the Trust Indenture Act, the Preferred Guarantee Trustee and
                 Guarantor shall in all respects comply with the provisions of
                 Section 310(b) of the Trust Indenture Act.

Section 4.2.     Appointment, Removal and Resignation of Preferred Guarantee
                 Trustees.

         (a)     Subject to Section 4.2(b), the Preferred Guarantee Trustee may
                 be appointed or removed without cause at any time by the
                 Guarantor.

         (b)     The Preferred Guarantee Trustee shall not be removed in
                 accordance with Section 4.2(a) until a Successor Preferred
                 Guarantee Trustee has been appointed and has accepted such
                 appointment by written instrument executed by such Successor
                 Preferred Guarantee Trustee and delivered to the Guarantor and
                 the resigning Preferred Guarantee Trustee.

         (c)     The Preferred Guarantee Trustee appointed to office shall hold
                 office until a Successor Preferred Guarantee Trustee shall have
                 been appointed or until its removal or resignation. The
                 Preferred Guarantee Trustee may resign from office (without
                 need for prior or subsequent accounting) by an instrument in
                 writing executed by the Preferred Guarantee Trustee and

                                       13


<PAGE>   17



                 delivered to the Guarantor, which resignation shall not take
                 effect until a Successor Preferred Guarantee Trustee has been
                 appointed and has accepted such appointment by instrument in
                 writing executed by such Successor Preferred Guarantee Trustee
                 and delivered to the Guarantor and the resigning Preferred
                 Guarantee Trustee.

         (d)     If no Successor Preferred Guarantee Trustee shall have been
                 appointed and accepted appointment as provided in this Section
                 4.2 within 60 days after delivery to the Guarantor of an
                 instrument of resignation, the resigning Preferred Guarantee
                 Trustee may petition any court of competent jurisdiction for
                 appointment of a Successor Preferred Guarantee Trustee. Such
                 court may thereupon, after prescribing such notice, if any, as
                 it may deem proper, appoint a Successor Preferred Guarantee
                 Trustee.

                                    ARTICLE V

                                    Guarantee

Section 5.1.     Guarantee.

                 The Guarantor irrevocably and unconditionally agrees to pay in
full to the Holders the Guarantee Payments (without duplication of amounts
theretofore paid by the Issuer), as and when due, regardless of any defense,
right of set-off or counterclaim that the Issuer may have or assert. The
Guarantor's obligation to make a Guarantee Payment may be satisfied by direct
payment of the required amounts by the Guarantor to the Holders or by causing
the Issuer to pay such amounts to the Holders.

Section 5.2.     Subordination.

                 If an event of default under the Indenture has occurred and is
continuing, the rights of holders of the Common Securities to receive payments
under the Common Securities Guarantee Agreement are subordinated to the rights
of Holders of Preferred Securities to receive Guarantee Payments.

Section 5.3.     Waiver of Notice and Demand.

                 The Guarantor hereby waives notice of acceptance of this
Guarantee Agreement and of any liability to which it applies or may apply,
presentment, demand for payment, any right to require a proceeding first against
the Issuer or any other Person before proceeding against the Guarantor, protest,
notice of

                                       14


<PAGE>   18

nonpayment, notice of dishonor, notice of redemption and all other notices and
demands.

Section 5.4.     Obligations Not Affected.

                 The obligations, covenants, agreements and duties of the
Guarantor under this Guarantee Agreement shall in no way be affected or impaired
by reason of the happening from time to time of any of the following:

         (a)     the release or waiver, by operation of law or otherwise, of the
                 performance or observance by the Issuer of any express or
                 implied agreement, covenant, term or condition relating to the
                 Preferred Securities to be performed or observed by the Issuer;

         (b)     the extension of time for the payment by the Issuer of all or
                 any portion of the Distributions, Redemption Price, Liquidation
                 Distribution or any other sums payable under the terms of the
                 Preferred Securities or the extension of time for the
                 performance of any other obligation under, arising out of, or
                 in connection with, the Preferred Securities (other than an
                 extension of time for payment of Distributions, Redemption
                 Price, Liquidation Distribution or other sums payable that
                 results from the extension of any interest payment period on
                 the Notes or any extension of the maturity date of the Notes
                 permitted by the Indenture);

         (c)     any failure, omission, delay or lack of diligence on the part
                 of the Holders to enforce, assert or exercise any right,
                 privilege, power or remedy conferred on the Holders pursuant to
                 the terms of the Preferred Securities, or any action on the
                 part of the Issuer granting indulgence or extension of any
                 kind;

         (d)     the voluntary or involuntary liquidation, dissolution, sale of
                 any collateral, receivership, insolvency, bankruptcy,
                 assignment for the benefit of creditors, reorganization,
                 arrangement, composition or readjustment of debt of, or other
                 similar proceedings affecting, the Issuer or any of the assets
                 of the Issuer;

         (e)     any invalidity of, or defect or deficiency in the Preferred
                 Securities;

         (f)     the settlement or compromise of any obligation guaranteed
                 hereby or hereby incurred; or

         (g)     any other circumstance whatsoever that might otherwise
                 constitute a legal or equitable discharge or defense of

                                       15


<PAGE>   19



                 a guarantor, it being the intent of this Section 5.4 that the
                 obligations of the Guarantor hereunder shall be absolute and
                 unconditional under any and all circumstances.

                 There shall be no obligation of the Holders to give notice to,
or obtain consent of, the Guarantor with respect to the happening of any of the
foregoing.

Section 5.5.     Rights of Holders.

         (a)     The Holders of a Majority in liquidation amount of the
                 Preferred Securities have the right to direct the time, method
                 and place of conducting of any proceeding for any remedy
                 available to the Preferred Guarantee Trustee in respect of this
                 Guarantee Agreement or exercising any trust or power conferred
                 upon the Preferred Guarantee Trustee under this Guarantee
                 Agreement.

   
         (b)     If the Preferred Guarantee Trustee fails to enforce this
                 Guarantee Agreement, any Holder of Preferred Securities may
                 institute a legal proceeding directly against the Guarantor to
                 enforce its rights under this Guarantee Agreement, without
                 first instituting a legal proceeding against the Issuer, the
                 Preferred Guarantee Trustee or any other Person.
    

Section 5.6.     Guarantee of Payment.

                 This Guarantee Agreement creates a guarantee of payment and not
of collection.

Section 5.7.     Subrogation.

                 The Guarantor shall be subrogated to all (if any) rights of the
Holders of Preferred Securities against the Issuer in respect of any amounts
paid to such Holders by the Guarantor under this Guarantee Agreement; provided,
however, that the Guarantor shall not (except to the extent required by
mandatory provisions of law) be entitled to enforce or exercise any right that
it may acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Guarantee Agreement,
if, at the time of any such payment, any amounts are due and unpaid under this
Guarantee Agreement. If any amount shall be paid to the Guarantor in violation
of the preceding sentence, the Guarantor agrees to hold such amount in trust for
the Holders and to pay over such amount to the Holders.

                                       16


<PAGE>   20


Section 5.8.     Independent Obligations.

                 The Guarantor acknowledges that its obligations hereunder are
independent of the obligations of the Issuer with respect to the Preferred
Securities, and that the Guarantor shall be liable as principal and as debtor
hereunder to make Guarantee Payments pursuant to the terms of this Guarantee
Agreement notwithstanding the occurrence of any event referred to in subsections
(a) through (g), inclusive, of Section 5.4 hereof.

                                   ARTICLE VI

                    Limitation of Transactions; Subordination

Section 6.1.     Limitation of Transactions.

                 So long as any Preferred Securities remain outstanding, if
there shall have occurred an Event of Default or an event of default under the
Declaration, then (a) the Guarantor shall not declare or pay any dividend on, or
make any distribution with respect to, or redeem, purchase or acquire or make a
liquidation payment with respect to, any of its capital stock and (b) the
Guarantor shall not make any payment of interest, principal or premium, if any,
on or repay, repurchase or redeem any debt securities issued by the Guarantor
which rank pari passu with or junior to the Notes, provided, that, the foregoing
restriction in this Section 6.1(a) shall not apply to any stock dividends paid
by the Guarantor, where the dividend stock is the same stock as that on which
the dividend is being paid.

Section 6.2.     Ranking.

                 This Guarantee Agreement will constitute an unsecured
obligation of the Guarantor and will rank (i) subordinate and junior in right of
payment to all other liabilities of the Guarantor (other than the Common
Securities Guarantee or any guarantee now or hereafter entered into by the
Guarantor in respect of any preferred or preference stock of any Affiliate of
the Guarantor), (ii) pari passu with the most senior preferred or preference
stock now or hereafter issued by the Guarantor and with any guarantee now or
hereafter entered into by the Guarantor in respect of any preferred or
preference stock of any Affiliate of the Guarantor, and (iii) senior to the
Guarantor's common stock.

                                       17


<PAGE>   21



                                   ARTICLE VII

                                   Termination

Section 7.1.     Termination.

                 This Guarantee Agreement shall terminate upon (i) full payment
of the Redemption Price of all Preferred Securities, (ii) the distribution of
the Notes to the Holders of all Preferred Securities or (iii) full payment of
the amounts payable in accordance with the Declaration upon liquidation of the
Issuer. Notwithstanding the foregoing, this Guarantee Agreement will continue to
be effective or will be reinstated, as the case may be, if at any time any
Holder of Preferred Securities must restore payment of any sums paid under the
Preferred Securities or under this Preferred Securities Guarantee.
Notwithstanding anything contained herein to the contrary, the obligations of
the Guarantor set forth in Article VIII hereof shall survive termination of this
Guarantee Agreement or the earlier resignation or removal of the Preferred
Guarantee Trustee.

                                  ARTICLE VIII

                                 Indemnification

Section 8.1.     Exculpation.

         (a) No Indemnified Person shall be liable, responsible or accountable
in damages or otherwise to the Guarantor or any Covered Person for any loss,
damage or claim incurred by reason of any act or omission performed or omitted
by such Indemnified Person in good faith in accordance with this Guarantee
Agreement and in a manner that such Indemnified Person reasonably believed to be
within the scope of the authority conferred on such Indemnified Person by this
Guarantee Agreement or by law, except that an Indemnified Person shall be liable
for any such loss, damage or claim incurred by reason of such Indemnified
Person's negligence or willful misconduct with respect to such acts or
omissions.

         (b) An Indemnified Person shall be fully protected in relying in good
faith upon the records of the Guarantor and upon such information, opinions,
reports or statements presented to the Guarantor by any Person as to matters the
Indemnified Person reasonably believes are within such other Person's
professional or expert competence and who has been selected with reasonable care
by or on behalf of the Guarantor, including information, opinions, reports or
statements as to the value and amount of the assets, liabilities, profits,
losses, or any other facts pertinent to the existence and amount of assets from
which

                                       18


<PAGE>   22


Distributions to Holders of Preferred Securities might properly be paid.

Section 8.2.     Indemnification.

         (a) To the fullest extent permitted by applicable law, the Guarantor
shall indemnify and hold harmless each Indemnified Person from and against any
loss, damage or claim incurred by such Indemnified Person in connection with
this Guarantee Agreement including without limitation by reason of any act or
omission performed or omitted by such Indemnified Person in good faith in
accordance with this Guarantee Agreement and in a manner such Indemnified Person
reasonably believed to be within the scope of authority conferred on such
Indemnified Person by this Guarantee Agreement, except that no Indemnified
Person shall be entitled to be indemnified in respect of any loss, damage or
claim incurred by such Indemnified Person by reason of negligence or willful
misconduct with respect to such acts or omissions.

         (b) To the fullest extent permitted by applicable law, expenses
(including legal fees) incurred by an Indemnified Person in defending any claim,
demand, action, suit or proceeding shall, from time to time, be advanced by the
Guarantor prior to the final disposition of such claim, demand, action, suit or
proceeding upon receipt by the Guarantor of any undertaking by or on behalf of
the Indemnified Person to repay such amount if it shall be determined that the
Indemnified Person is not entitled to be indemnified as authorized in Section
8.2(a).

                                   ARTICLE IX

                                  Miscellaneous

Section 9.1.     Successors and Assigns.

                 All guarantees and agreements contained in this Guarantee
Agreement shall bind the successors, assigns, receivers, trustees and
representatives of the Guarantor and shall inure to the benefit of the Holders
of the Preferred Securities then outstanding.

Section 9.2.     Amendments.

                 Except with respect to any changes that do not adversely affect
the rights of Holders (in which case no consent of Holders will be required),
this Guarantee Agreement may only be amended with the prior approval of the
Holders of at least 66-2/3% in liquidation amount (including the stated amount
that would be paid on redemption, liquidation or otherwise, plus

                                       19


<PAGE>   23


accrued and unpaid Distributions to the date upon which the voting percentages
are determined) of all the outstanding Preferred Securities (as defined in the
Declaration). The provisions of Section 12.2 of the Declaration with respect to
meetings of Holders of the Trust Securities apply to the giving of such
approval. The Preferred Guarantee Trustee may, but shall have no obligation to,
execute and deliver any amendment to this Guarantee Agreement which affects the
Preferred Guarantee Trustee's rights, duties or immunities hereunder or
otherwise.

Section 9.3.     Notices.

                 All notices provided for in this Guarantee Agreement shall be
in writing, duly signed by the party giving such notice, and shall be delivered,
telecopied or mailed by registered or certified mail as follows:

         (a)     If given to the Preferred Guarantee Trustee, at the Preferred
                 Guarantee Trustee's mailing address set forth below (or such
                 other address as the Preferred Guarantee Trustee may give
                 notice of to the Holders of the Preferred Securities):

                          Harris Trust and Savings Bank
                          311 West Monroe Street, 12th Floor
                          Chicago, Illinois  60606
                          Attention:  Indenture Trust Administration
                          Telecopy Number: (312) 461-3525

         (b)     If given to the Guarantor, at the Guarantor's mailing address
                 set forth below (or such other address as the Guarantor may
                 give notice of to the Holders of the Preferred Securities):

                          Southwest Gas Corporation
                          5241 Spring Mountain Road
                          Las Vegas,  Nevada  89102
                          Telecopy Number: (702) 876-7037

         (c)     If given to any Holder of Preferred Securities, at the address
                 set forth in the books and records of the Issuer.

                 All such notices shall be deemed to have been given when
received in person, telecopied with receipt confirmed, or mailed by first class
mail, postage prepaid except that if a notice or other document is refused
delivery or cannot be delivered because of a changed address of which no notice
was given, such notice or other document shall be deemed to have been delivered
on the date of such refusal or inability to deliver.

                                      20


<PAGE>   24


Section 9.4.     Benefit.

                 This Guarantee Agreement is solely for the benefit of the
Holders of the Preferred Securities and, subject to Section 3.1(a), is not
separately transferable from the Preferred Securities.

Section 9.5.     Governing Law.

                 THIS GUARANTEE AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

                 IN WITNESS WHEREOF, the parties hereto have caused this
Guarantee Agreement to be executed by their respective officers thereunto duly
authorized, as of the day and year first above written.

                                           SOUTHWEST GAS CORPORATION

                                           By:
                                              -------------------------------
                                              Name:
                                              Title:

                                           HARRIS TRUST AND SAVINGS BANK,
                                           as Preferred Guarantee Trustee

                                           By:
                                              --------------------------------
                                              Name:
                                              Title:

                                       21



<PAGE>   1
================================================================================



                   AMENDED AND RESTATED DECLARATION OF TRUST


                            SOUTHWEST GAS CAPITAL I





                           Dated as of ________, ____




================================================================================



                                  Exhibit 4.06
<PAGE>   2
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                                    Page #
                                                                                                                    ------
<S>                                                                                                                 <C>
ARTICLE I
                                                    Interpretation and Definitions  . . . . . . . . . . .              2
         Section 1.1  Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              2

ARTICLE II
                                                         Trust Indenture Act  . . . . . . . . . . . . . .              9
         Section 2.1  Trust Indenture Act; Application  . . . . . . . . . . . . . . . . . . . . . . . . .              9
         Section 2.2  Lists of Holders of Trust Securities  . . . . . . . . . . . . . . . . . . . . . . .              9
         Section 2.3  Reports by the Property Trustee . . . . . . . . . . . . . . . . . . . . . . . . . .             10
         Section 2.4  Periodic Reports to Property Trustee  . . . . . . . . . . . . . . . . . . . . . . .             10
         Section 2.5  Evidence of Compliance with Conditions Precedent  . . . . . . . . . . . . . . . . .             10
         Section 2.6  Events of Default; Waiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             10
         Section 2.7  Event of Default; Notice  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             12

ARTICLE III
                                                             Organization . . . . . . . . . . . . . . . .             13
         Section 3.1  Name  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             13
         Section 3.2  Office  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             13
         Section 3.3  Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             13
         Section 3.4  Authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             13
         Section 3.5  Title to Property of the Trust  . . . . . . . . . . . . . . . . . . . . . . . . . .             14
         Section 3.6  Powers and Duties of the Regular Trustees . . . . . . . . . . . . . . . . . . . . .             14
         Section 3.7  Prohibition of Actions by the Trust and the Trustees  . . . . . . . . . . . . . . .             17
         Section 3.8  Powers and Duties of the Property Trustee . . . . . . . . . . . . . . . . . . . . .             18
         Section 3.9  Certain Duties and Responsibilities of the Property Trustee . . . . . . . . . . . .             20
         Section 3.10 Certain Rights of Property Trustee  . . . . . . . . . . . . . . . . . . . . . . . .             22
         Section 3.11 Delaware Trustee  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             25
         Section 3.12 Execution of Documents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             25
         Section 3.13 Not Responsible for Recitals or Issuance of Trust Securities  . . . . . . . . . . .             26
         Section 3.14 Duration of Trust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             26
         Section 3.15 Mergers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             26
</TABLE>





                                       i
<PAGE>   3
                                                          
<TABLE>
<S>                                                                                                                   <C>
ARTICLE IV
                                                               Sponsor  . . . . . . . . . . . . . . . . .             28
         Section 4.1  Sponsor's Purchase of Common Securities . . . . . . . . . . . . . . . . . . . . . .             28
         Section 4.2  Responsibilities of the Sponsor . . . . . . . . . . . . . . . . . . . . . . . . . .             28

ARTICLE V
                                                               Trustees . . . . . . . . . . . . . . . . .             29
         Section 5.1  Number of Trustees  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             29
         Section 5.2  Delaware Trustee  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             29
         Section 5.3  Property Trustee; Eligibility . . . . . . . . . . . . . . . . . . . . . . . . . . .             29
         Section 5.4  Qualifications of Regular Trustees and Delaware Trustee Generally . . . . . . . . .             30
         Section 5.5  Initial Trustees  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             31
         Section 5.6  Appointment, Removal and Resignation of Trustees  . . . . . . . . . . . . . . . . .             31
         Section 5.7  Vacancies among Trustees  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             33
         Section 5.8  Effect of Vacancies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             33
         Section 5.9  Meetings  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             33
         Section 5.10 Delegation of Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             34

ARTICLE VI
                                                            Distributions   . . . . . . . . . . . . . . .             34
         Section 6.1  Distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             34

ARTICLE VII
                                                     Issuance of Trust Securities . . . . . . . . . . . .             35
         Section 7.1  General Provisions Regarding Trust Securities . . . . . . . . . . . . . . . . . . .             35

ARTICLE VIII
                                                             Termination  . . . . . . . . . . . . . . . .             36
         Section 8.1  Termination of Trust. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             36

ARTICLE IX
                                                         Transfer of Interest . . . . . . . . . . . . . .             37
         Section 9.1  Transfer of Trust Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . .             37
         Section 9.2  Transfer of Certificates  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             37
         Section 9.3  Deemed Trust Security Holders . . . . . . . . . . . . . . . . . . . . . . . . . . .             38
         Section 9.4  Book Entry Interests  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             38
         Section 9.5  Notices to Depositary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             39
         Section 9.6  Appointment of Successor Depositary . . . . . . . . . . . . . . . . . . . . . . . .             39
</TABLE>





                                       ii
<PAGE>   4
<TABLE>
<S>                                                                                                                   <C>
         Section 9.7  Definitive Preferred Security Certificates  . . . . . . . . . . . . . . . . . . . .             39
         Section 9.8  Mutilated, Destroyed, Lost or Stolen Certificates . . . . . . . . . . . . . . . . .             40

ARTICLE X
                                                 Limitation of Liability of Holders
                                               of Trust Securities, Trustees or Others  . . . . . . . . .             41
         Section 10.1  Liability  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             41
         Section 10.2  Exculpation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             41
         Section 10.3  Fiduciary Duty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             42
         Section 10.4  Indemnification  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             43
         Section 10.5  Outside Businesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             44

ARTICLE XI
                                                              Accounting  . . . . . . . . . . . . . . . .             44
         Section 11.1  Fiscal Year  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             44
         Section 11.2  Certain Accounting Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . .             44
         Section 11.3  Banking  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             45
         Section 11.4  Withholding  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             46

ARTICLE XII
                                                       Amendments and Meetings  . . . . . . . . . . . . .             46
         Section 12.1  Amendments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             46
         Section 12.2  Meetings of the Holders of Trust Securities; Action by Written Consent . . . . . .             48

ARTICLE XIII
                                                  Representations and Warranties of
                                                Property Trustee and Delaware Trustee . . . . . . . . . .             50
         Section 13.1  Representations and Warranties of Property Trustee . . . . . . . . . . . . . . . .             50
         Section 13.2  Representations and Warranties of Delaware Trustee . . . . . . . . . . . . . . . .             51

ARTICLE XIV
                                                            Miscellaneous   . . . . . . . . . . . . . . .             52
         Section 14.1  Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              52
         Section 14.2  Governing Law  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             53
         Section 14.3  Intention of the Parties . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             53
         Section 14.4  Headings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             53
         Section 14.5  Successors and Assigns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             53
         Section 14.6  Partial Enforceability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             53
</TABLE>





                                      iii
<PAGE>   5
<TABLE>
<S>                                                                                                                 <C>
         Section 14.7  Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             54

EXHIBIT A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            A-1

ANNEX I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            I-1

ANNEX II  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .           II-1
</TABLE>


                                       iv
<PAGE>   6
                   AMENDED AND RESTATED DECLARATION OF TRUST


         AMENDED AND RESTATED DECLARATION OF TRUST ("Declaration") dated and
effective as of __________, ____, by the undersigned trustees (together with
all other Persons from time to time duly appointed and serving as trustees in
accordance with the provisions of this Declaration, the "Trustees"), Southwest
Gas Corporation, a California corporation, as trust sponsor (the "Sponsor"),
Harris Trust and Savings Bank, an Illinois banking corporation, as property
trustee (the "Property Trustee") and by the holders, from time to time, of
undivided beneficial interests in the Trust to be issued pursuant to this
Declaration;

         WHEREAS, the Trustees and the Sponsor established a trust (the
"Trust") under the Delaware Business Trust Act pursuant to a Declaration of
Trust dated as of August 17, 1995, (the "Original Declaration") and a
Certificate of Trust filed with the Secretary of State of Delaware on August
17, 1995, for the sole purpose of issuing and selling certain securities
representing undivided beneficial interests in the assets of the Trust and
investing the proceeds thereof in certain Notes of the Note Issuer (as
hereinafter defined);

         WHEREAS, as of the date hereof, no interests in the Trust have been
issued;

         WHEREAS, all of the Trustees and the Sponsor, by this Declaration,
amend and restate each and every term and provision of the Original
Declaration; and

         NOW, THEREFORE, it being the intention of the parties hereto to
continue the Trust as a business trust under the Business Trust Act and that
this Declaration constitute the governing instrument of such business trust,
the Trustees declare that all assets contributed to the Trust will be held in
trust for the benefit of the holders, from time to time, of the securities
representing undivided beneficial interests in the assets of the Trust issued
hereunder, subject to the provisions of this Declaration.





                                       1
<PAGE>   7
                                   ARTICLE I
                       Interpretation and Definitions(1)

Section 1.1  Definitions.

         (a)     Capitalized terms used in this Declaration but not defined in
                 the preamble above have the respective meanings assigned to
                 them in this Section 1.1;

         (b)     a term defined anywhere in this Declaration has the same
                 meaning throughout;

         (c)     all references to "the Declaration" or "this Declaration" are
                 to this Declaration as modified, supplemented or amended from
                 time to time;

         (d)     all references in this Declaration to Articles and Sections
                 and Exhibits are to Articles and Sections of and Exhibits to
                 this Declaration unless otherwise specified;

         (e)     a term defined in the Trust Indenture Act has the same meaning
                 when used in this Declaration unless otherwise defined in this
                 Declaration or unless the context otherwise requires; and

         (f)     a reference to the singular includes the plural and vice versa.

         ["Additional Preferred Securities" has the meaning specified in
Exhibit A hereto.]

         "Affiliate" has the same meaning as given to that term in Rule 405 of
the Securities Act or any successor rule thereunder.

         "Authorized Officer" of a Person means any Person that is authorized
to bind such Person.

         "Book Entry Interest" means a beneficial interest in a Global
Certificate, ownership and transfers of which shall be maintained and made
through book entries by a Depositary as described in Section 9.4.

         "Business Day" means any day other than a day on which banking
institutions in New York, New York, Los Angeles, California or Chicago,
Illinois are authorized or required by law to close.





- --------------------
(1)  Include appropriate brackets if over-allotment option is exercised.


                                       2
<PAGE>   8
         "Business Trust Act" means Chapter 38 of Title 12 of the Delaware Code,
12 Del. Code Section 3801 et seq., as it may be amended from time to time.

         "Certificate" means a Common Security Certificate or a Preferred
Security Certificate.

         "Closing Date" means [each of] ____________, ____ [and any other date
on which payment is made for any Preferred Securities in connection with the
exercise of the over-allotment option pursuant to the Underwriting Agreement.]

         "Code" means the Internal Revenue Code of 1986, as amended from time
to time, or any successor legislation.

         "Commission" means the Securities and Exchange Commission, as from
time to time constituted, created under the Exchange Act or, if at any time
after the execution of this instrument such Commission is not existing and
performing the duties now assigned to it under the Trust Indenture Act, then
the body performing such duties at such time.

         "Common Security" has the meaning specified in Section 7.1.

         "Common Securities Guarantee" means the guarantee agreement to be
dated as of ________, ____, of the Sponsor in respect of the Common Securities.

         "Common Security Certificate" means a definitive certificate in fully
registered form representing a Common Security substantially in the form of
Annex II to Exhibit A.

         "Corporate Trust Office" means the principal office of the Trustee at
which at any particular time its corporate trust business shall be administered
which office at the date of execution of this Declaration is located at 311
West Monroe Street, 12th Floor, Chicago, Illinois 60606, Attention:  Indenture
Trust Division.

         "Covered Person" means: (a) any officer, director, shareholder,
partner, member, representative, employee or agent of (i) the Trust or (ii) the
Trust's Affiliates; and (b) any Holder of Trust Securities.

         "Delaware Trustee" has the meaning set forth in Section 5.2.

         "Definitive Preferred Security Certificates" has the meaning set forth
in Section 9.4.

         "Depositary" means an organization registered as a clearing agency
pursuant to Section 17A of the Exchange Act that is acting as depositary for
the Preferred Securities and in whose name or





                                       3
<PAGE>   9
in the name of a nominee of that organization shall be registered a Global
Certificate and which shall undertake to effect book entry transfers and
pledges of the Preferred Securities.

         "Depositary Participant" means a broker, dealer, bank, other financial
institution or other Person for whom from time to time the Depositary effects
book entry transfers and pledges of securities deposited with the Depositary.

         "Direction" by a Person means a written direction signed:

         (a)     if the Person is a natural person, by that Person; or

         (b)     in any other case, in the name of such Person by one or more
                 Authorized Officers of that Person.

         "Distribution" means a distribution payable to Holders of Trust
Securities in accordance with Section 6.1.

         "DTC" means The Depository Trust Company, the initial Depositary.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended
from time to time, or any successor legislation.

         "Event of Default", in respect of the Trust Securities, means an Event
of Default (as defined in the Indenture) has occurred and is continuing in
respect of the Notes.

         "Global Certificate" has the meaning specified in Section 9.4.

         "Holder" means a Person in whose name a Certificate representing a
Trust Security is registered on the books and records of the Trust, such Person
being a beneficial owner within the meaning of the Business Trust Act,
provided, that, in determining whether the holders of the requisite percentage
of Preferred Securities have given any request, notice, consent or waiver
hereunder, "Holder" shall not include the Sponsor, as guarantor of the Trust
Securities, or any Affiliate of the Sponsor.

         "Indemnified Person: means (a) any Trustee or the Property Trustee;
(b) any Affiliate of any Trustee or the Property Trustee; (c) any officers,
directors, shareholders, members, partners, employees, representatives or
agents of any Trustee or the Property Trustee; or (d) any employee or agent of
the Trust or its Affiliates.

         "Indenture" means the Indenture dated as of _________, ____ among the
Note Issuer and the Note Trustee as supplemented by the





                                       4
<PAGE>   10
First Supplemental Indenture dated as of  ___, ____ and any other indenture
supplemental thereto.

         "Investment Company" means an investment company as defined in the
Investment Company Act.

         "Investment Company Act" means the Investment Company Act of 1940, as
amended from time to time, or any successor legislation.

         "Legal Action" has the meaning set forth in Section 3.6(g).

         "Ministerial Action" has the meaning set forth in the terms of the
Trust Securities as set forth in Exhibit A.

         "Majority in liquidation amount" means, except as provided in the
terms of the Trust Securities and the Trust Indenture Act, Holder(s) of
outstanding Trust Securities voting together as a single class or, as the
context may require, Holders of outstanding Preferred Securities or Holders of
outstanding Common Securities voting separately as a class, who are the record
owners of more than 50% of the aggregate liquidation amount (including the
stated amount that would be paid on redemption, liquidation or otherwise, plus
accrued and unpaid Distributions to the date upon which the voting percentages
are determined) of all outstanding Trust Securities of the relevant class.

         "Note Issuer" means the Sponsor in its capacity as issuer of the Notes.

         "Note Trustee" means Harris Trust and Savings Bank, as trustee under
the Indenture until a successor is appointed thereunder, and thereafter means
such successor trustee.

         "Notes" means the series of Notes to be issued by the Note Issuer
under the Indenture to be held by the Property Trustee.

         "Officers' Certificate" means, with respect to any Person, a
certificate signed by two Authorized Officers of such Person.  Any Officers'
Certificate delivered with respect to compliance with a condition or covenant
provided for in this Declaration shall include:

         (a)     a statement that each officer signing the Certificate has read
                 the covenant or condition and the definition relating thereto;

         (b)     a brief statement of the nature and scope of the examination
                 or investigation undertaken by each officer in rendering the
                 Certificate;

         (c)     a statement that each such officer has made such examination
                 or investigation as, in such officer's





                                       5
<PAGE>   11
                 opinion, is necessary to enable such officer to express an
                 informed opinion as to whether or not such covenant or
                 condition has been complied with; and

         (d)     a statement as to whether, in the opinion of each such
                 officer, such condition or covenant has been complied with.

         "Paying Agent" has the meaning specified in Section 3.8(h).

         "Person" means a legal person, including any individual, corporation,
estate, partnership, joint venture, association, joint stock company, limited
liability company, trust, unincorporated association, or government or any
agency or political subdivision thereof, or any other entity of whatever
nature.

         "Preferred Securities Guarantee" means the guarantee agreement to be
dated as of _____, ____, of the Sponsor in respect of the Preferred Securities.

         "Preferred Security" has the meaning specified in Section 7.1.

         "Preferred Security Beneficial Owner" means, with respect to a Book
Entry Interest, a Person who is the beneficial owner of such Book Entry
Interest, as reflected on the books of the Depositary, or on the books of a
Person maintaining an account with such Depositary (directly as a Depositary
Participant or as an indirect participant, in each case in accordance with the
rules of such Depositary).

         "Preferred Security Certificate" means a certificate representing a
Preferred Security substantially in the form of Annex I to Exhibit A.

         "Pricing Agreement" means the pricing agreement between the Trust, the
Note Issuer, and the underwriters designated by the Regular Trustees with
respect to the offer and sale of the Preferred Securities.

         "Property Trustee" means Harris Trust and Savings Bank, an Illinois
banking corporation in its capacity as property trustee, or any successor
trustee meeting the eligibility requirements set forth in Section 5.3.

         "Property Trustee Account" has the meaning set forth in Section 3.8(c).

         "Prospectus Supplement" means that certain Prospectus Supplement dated
as of ______ __, ____ relating to the _____ Preferred Securities.





                                       6
<PAGE>   12

         "Quorum" means a majority of the Regular Trustees or, if there are
only two Regular Trustees, both of them.

         "Regular Trustee" means any Trustee other than the Delaware Trustee.

         "Related Party" means, with respect to the Sponsor, any direct or
indirect wholly owned subsidiary of the Sponsor or any other Person that owns,
directly or indirectly, 100% of the outstanding voting securities of the
Sponsor.

         "Responsible Officer" means, with respect to the Property Trustee, any
vice-president, any assistant vice-president, the secretary, any assistant
secretary, the treasurer, any assistant treasurer, any trust officer or
assistant trust officer or any other officer in the Corporate Trust Office of
the Property Trustee customarily performing functions similar to those
performed by any of the above designated officers and also means, with respect
to a particular corporate trust matter, any other officer to whom such matter
is referred because of that officer's knowledge of and familiarity with the
particular subject.

         "Rule 3a-5" means Rule 3a-5 under the Investment Company Act.

         "Securities Act" means the Securities Act of 1933, as amended from
time to time, or any successor legislation.

         "66-2/3% in liquidation amount" means, except as provided in the terms
of the Trust Securities and by the Trust Indenture Act, Holders of outstanding
Trust Securities voting together as a single class or, as the context may
require, Holders of outstanding Preferred Securities or Holder(s) of
outstanding Common Securities voting separately as a class, representing at
least 66-2/3% of the aggregate liquidation amount (including the stated amount
that would be paid on redemption, liquidation or otherwise, plus accrued and
unpaid Distributions, to the date upon which the voting percentages are
determined) of all outstanding Trust Securities of the relevant class.

         "Sponsor" means Southwest Gas Corporation, a California corporation,
or any successor entity in a merger, consolidation or amalgamation, in its
capacity as sponsor of the Trust.

         "Tax Event" means the receipt by, and upon the request of, the Regular
Trustees of an opinion of nationally recognized independent tax counsel
experienced in such matters to the effect that, as a result of (a) any
amendment to, or change (including any announced prospective change) in, the
laws (or any regulations thereunder) of the United States or any political
subdivision or taxing authority thereof or therein, (b) any amendment to or
change in an interpretation or application of





                                       7
<PAGE>   13
such laws or regulations by any legislative body, court, governmental agency or
regulatory authority (including the enactment of any legislation and the
publication of any judicial decision or regulatory determination on or after
the date of the Prospectus Supplement), (c) any interpretation or pronouncement
by any such body, court, agency or authority that provides for a position with
respect to such laws or regulations that differs from the theretofore generally
accepted position, or (d) any action taken by any governmental agency or
regulatory authority, which amendment or change is enacted, promulgated or
effective, or which interpretation or pronouncement is issued or announced, or
which action is taken, in each case on or after the date of the Prospectus
Supplement, there is more than an insubstantial risk that (i) the Trust is, or
within 90 days of the date thereof will, be subject to United States federal
income tax with respect to income accrued or received on the Subordinated Debt
Securities, (ii) interest payable to the Trust on the Subordinated Debt
Securities is, or within 90 days of the date thereof will, not be deductible in
whole or in part, by the Note Issuer for United States federal income tax
purposes or (iii) the Trust is, or within 90 days of the date thereof will, be
subject to more than a de minimis amount of other taxes, duties or other
governmental charges.

         "10% in liquidation amount" means, except as provided in the terms of
the Trust Securities or by the Trust Indenture Act, Holders of outstanding
Trust Securities voting together as a single class or, as the context may
require, Holders of outstanding Preferred Securities or Holders of outstanding
Common Securities, voting separately as a class, representing at least 10% of
the aggregate liquidation amount (including the stated amount that would be
paid on redemption, liquidation or otherwise, plus accrued and unpaid
Distributions to the date upon which the voting percentages are determined) of
all outstanding Trust Securities of the relevant class.

         "Treasury Regulations" means the income tax regulations, including
temporary and proposed regulations, promulgated under the Code by the United
States Treasury, as such regulations may be amended from time to time
(including corresponding provisions of succeeding regulations).

         "Trustee" or "Trustees" means each Person who has signed this
Declaration as a trustee, other than the Property Trustee, so long as such
person shall continue in office in accordance with the terms hereof, and all
other Persons who may from time to time be duly appointed, qualified and
serving as Trustees in accordance with the provisions hereof, and references
herein to a Trustee or the Trustees shall refer to such Person or Persons
solely in their capacity as trustees hereunder.





                                       8
<PAGE>   14
         "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
effect at the date as of which this instrument was executed, provided, however,
that in the event the Trust Indenture Act of 1939 is amended after such date,
"Trust Indenture Act" means, to the extent required by any such amendment, the
Trust Indenture Act of 1939 as so amended.

         "Trust Securities" means collectively the Common Securities and the
Preferred Securities.

         "Underwriting Agreement" means the Underwriting Agreement for the
offering and sale of Preferred Securities.


                                   ARTICLE II
                              Trust Indenture Act

Section 2.1  Trust Indenture Act; Application

         (a)     This Declaration is subject to the provisions of the Trust
                 Indenture Act that are required to be part of this Declaration
                 and shall, to the extent applicable, be governed by such
                 provisions.

         (b)     The Property Trustee shall be the only Trustee which is a
                 Trustee for the purposes of the Trust Indenture Act.

         (c)     If and to the extent that any provision of this Declaration
                 limits, qualifies or conflicts with the duties imposed by
                 Sections 310 to 317, inclusive, of the Trust Indenture Act,
                 such duties imposed by the Trust Indenture Act shall control.

         (d)     The application of the Trust Indenture Act to this Declaration
                 shall not affect the nature of the Trust Securities as equity
                 securities representing undivided beneficial interests in the
                 assets of the Trust.

Section 2.2  Lists of Holders of Trust Securities.

         (a)     Each of the Sponsor and the Regular Trustees on behalf of the
                 Trust shall provide the Property Trustee (i) within 14 days
                 after each record date for payment of Distributions, a list,
                 in such form as the Property Trustee may reasonably require,
                 of the names and addresses of the Holders of the Trust
                 Securities ("List of Holders") as of such record date,
                 provided that none of the Sponsor or the Regular Trustees on
                 behalf of the Trust shall be obligated to provide such list of
                 Holders at any time the List of Holders does not differ from
                 the most recent List of Holders given to the Property Trustee
                 by the Sponsor and the Regular





                                       9
<PAGE>   15
                 Trustees on behalf of the Trust, and (ii) at any other time,
                 within 30 days of receipt by the Trust of a written request for
                 a List of Holders as of a date no more than 14 days before such
                 List of Holders is given to the Property Trustee.  The Property
                 Trustee shall preserve, in as current a form as is reasonably
                 practicable, all information contained in Lists of Holders
                 given to it or which it receives in the capacity as Paying
                 Agent (if acting in such capacity) provided that the Property
                 Trustee may destroy any List of Holders previously given to it
                 on receipt of a new List of Holders.

         (b)     The Property Trustee shall comply with the obligations of an
                 indenture trustee under Sections 311(a), 311(b) and 312(b) of
                 the Trust Indenture Act.

Section 2.3  Reports by the Property Trustee.

         Within 60 days after ________ of each year, the Property Trustee shall
provide to the Holders of the Preferred Securities such reports as are required
by Section 313 of the Trust Indenture Act, if any, in the form and in the
manner provided by Section 313 of the Trust Indenture Act.  The Property
Trustee shall also comply with the requirements of Section 313(d) of the Trust
Indenture Act.

Section 2.4  Periodic Reports to Property Trustee.

         Each of the Sponsor and the Regular Trustees on behalf of the Trust
shall provide to the Property Trustee such documents, reports and information
as required by Section 314 (if any) and the compliance certificate required by
Section 314 of the Trust Indenture Act in the form, in the manner and at the
times required by Section 314 of the Trust Indenture Act.

Section 2.5  Evidence of Compliance with Conditions Precedent.

         Each of the Sponsor and the Regular Trustees on behalf of the Trust
shall provide to the Property Trustee such evidence of compliance with any
conditions precedent, if any, provided for in this Declaration that relate to
any of the matters set forth in Section 314(c) of the Trust Indenture Act.  Any
certificate or opinion required to be given by an officer pursuant to Section
314(c)(1) may be given in the form of an Officers' Certificate.

Section 2.6  Events of Default; Waiver

         (a)     The Holders of a Majority in liquidation amount of Preferred
                 Securities may, by vote, on behalf of the Holders of all of
                 the Preferred Securities, waive any past Event of Default in
                 respect of the Preferred





                                       10
<PAGE>   16
                 Securities and its consequences, provided that, if the
                 underlying Event of Default under the Indenture:

                 (i)      is not waivable under the Indenture, the Event of
                          Default under the Declaration shall also not be
                          waivable; or

                 (ii)     requires the consent or vote of all of the holders of
                          the Notes to be waived under the Indenture, the Event
                          of Default under the Declaration may only be waived
                          by the vote of all of the Holders of the Preferred
                          Securities.

                 Upon such waiver, any such default shall cease to exist, and
                 any Event of Default with respect to the Preferred Securities
                 arising therefrom shall be deemed to have been cured, for
                 every purpose of this Declaration, but no such waiver shall
                 extend to any subsequent or other default or an Event of
                 Default with respect to the Preferred Securities or impair any
                 right consequent thereon.  Any waiver by the Holders of the
                 Preferred Securities of an Event of Default with respect to
                 the Preferred Securities shall also be deemed to constitute a
                 waiver by the Holders of the Common Securities of any such
                 Event of Default with respect to the Common Securities for all
                 purposes of this Declaration without any further act, vote, or
                 consent of the Holders of the Common Securities.

         (b)     The Holders of a Majority in liquidation amount of the Common
                 Securities may, by vote, on behalf of the Holders of all of
                 the Common Securities, waive any past Event of Default with
                 respect to the Common Securities and its consequences,
                 provided that, if the underlying Event of Default under the
                 Indenture:

                 (i)      is not waivable under the Indenture, except where the
                          Holders of the Common Securities are deemed to have
                          waived such Event of Default under the Declaration as
                          provided below in this Section 2.6(b), the Event of
                          Default under the Declaration shall also not be
                          waivable; or

                 (ii)     requires the consent or vote of all of the holders of
                          the Notes to be waived, except where the Holders of
                          the Common Securities are deemed to have waived such
                          Event of Default under the Declaration as provided
                          below in this Section 2.6(b), the Event of Default
                          under the Declaration may only be waived by the vote
                          of all of the Holders of Common Securities;





                                       11
<PAGE>   17
                 provided that, each Holder of Common Securities will be deemed
                 to have waived any such Event of Default and all Events of
                 Default with respect to the Common Securities and its
                 consequences until all Events of Default with respect to the
                 Preferred Securities have been cured, waived or otherwise
                 eliminated, and until such Events of Default have been so
                 cured, waived or otherwise eliminated, the Property Trustee
                 will be deemed to be acting solely on behalf of the Holders of
                 the Preferred Securities and only the Holders of the Preferred
                 Securities will have the right to direct the Property Trustee
                 in accordance with the terms of the Trust Securities.  Subject
                 to the foregoing provisions of this Section 2.6(b), upon such
                 waiver, any such default shall cease to exist and any Event of
                 Default with respect to the Common Securities arising therefrom
                 shall be deemed to have been cured for every purpose of this
                 Declaration but no such waiver shall extend to any subsequent
                 or other default or Event of Default with respect to the Common
                 Securities or impair any right consequent thereon.

         (c)     A waiver of an Event of Default under the Indenture by the
                 Property Trustee at the direction of the Holders of the
                 Preferred Securities, constitutes a waiver of the
                 corresponding Event of Default under this Declaration.

Section 2.7  Event of Default; Notice.

         (a)     The Property Trustee shall, within 90 days after the
                 occurrence of an Event of Default, transmit by mail, first
                 class postage prepaid, to the Holders of the Trust Securities,
                 notices of all defaults with respect to the Trust Securities
                 known to the Property Trustee, unless such defaults have been
                 cured before the giving of such notice (the term "defaults"
                 for the purposes of this Section 2.7(a) being hereby defined
                 to be an Event of Default as defined in the Indenture, not
                 including any periods of grace provided for therein and
                 irrespective of the giving of any notice provided therein);
                 provided that, except for a default in the payment of
                 principal of (or premium, if any) or interest on any of the
                 Notes or in the payment of any sinking fund installment
                 established for the Notes, the Property Trustee shall be
                 protected in withholding such notice if and so long as
                 Responsible Officers of the Property Trustee in good faith
                 determine that the withholding of such notice is in the
                 interests of the Holders of the Trust Securities.

         (b)     The Property Trustee shall not be deemed to have knowledge of
                 any default except:





                                       12
<PAGE>   18

                 (i)      a default under Sections 501(1) and 501(2) of the
                          Indenture; or

                 (ii)     any default as to which a Responsible Officer of the
                          Property Trustee charged with the administration of
                          the Declaration shall have obtained written or actual
                          notice.


                                  ARTICLE III
                                  Organization

Section 3.1  Name.

         The Trust is named "Southwest Gas Capital I", as such name may be
modified from time to time by the Regular Trustees following written notice to
the Holders of Trust Securities.  The Trust's activities may be conducted under
the name of the Trust or any other name deemed advisable by the Regular
Trustees.

Section 3.2  Office.

         The address of the principal office of the Trust is c/o Southwest Gas
Corporation, 5241 Spring Mountain Road, Las Vegas, Nevada  89102.  On ten
Business Days written notice to the Holders of Trust Securities, the Regular
Trustees may designate another principal office.

Section 3.3  Purpose.

         The exclusive purposes and functions of the Trust are (a) to issue and
sell Trust Securities and use the proceeds from such sale to acquire the Notes
and (b) except as otherwise limited herein, to engage in only those other
activities necessary, or incident thereto.  The Trust shall not borrow money,
issue debt or reinvest proceeds derived from investments, pledge any of its
assets, or otherwise undertake (or permit to be undertaken) any activity that
would cause the Trust not to be classified for United States federal income tax
purposes as a grantor trust.  All provisions of this Declaration shall be
interpreted in a manner consistent with such purposes.

Section 3.4  Authority.

         Subject to the limitations provided in this Declaration, including the
provisions of Sections 3.11, 5.2 and 8.1(b), and to the specific duties of the
Property Trustee, the Regular Trustees shall have exclusive and complete
authority to carry out the purposes of the Trust.  An action taken by the
Regular Trustees in accordance with their powers shall constitute the act of
and serve to bind the Trust and an action taken by the Property Trustee in
accordance with its powers shall constitute the act of





                                       13
<PAGE>   19
and serve to bind the Trust.  In dealing with the Regular Trustees acting on
behalf of the Trust, no Person shall be required to inquire into the authority
of the Regular Trustees to bind the Trust.  Persons dealing with the Trust are
entitled to rely conclusively on the power and authority of the Trustees as set
forth in this Declaration.

Section 3.5  Title to Property of the Trust.

         Except as provided in Section 3.8 with respect to the Notes and the
Property Trustee Account or as otherwise provided in this Declaration, legal
title to all assets of the Trust shall be vested in the Trust.  The Holders
shall not have legal title to any part of the assets of the Trust, but shall
have an undivided beneficial interest in the assets of the Trust.

Section 3.6  Powers and Duties of the Regular Trustees.

         The Regular Trustees shall have the exclusive power, duty and
authority to cause the Trust to engage in the following activities:

         (a)     to issue and sell the Preferred Securities and the Common
                 Securities in accordance with this Declaration; provided,
                 however, that the Trust may issue no more than one series of
                 Preferred Securities and no more than one series of Common
                 Securities, and, provided further, that there shall be no
                 interests in the Trust other than the Trust Securities, and
                 the issuance of Trust Securities shall be limited to [a
                 one-time], simultaneous issuance of both Preferred Securities
                 and Common Securities on [the] [each] Closing Date;

         (b)     in connection with the issue and sale of the Preferred
                 Securities, at the direction of the Sponsor, to:

                 (i)      execute and file with the Commission the registration
                          statement on Form S-3 prepared by the Sponsor,
                          including any amendments thereto, pertaining to the
                          Preferred Securities;

                 (ii)     execute and file any documents prepared by the
                          Sponsor, or take any acts as determined by the
                          Sponsor to be necessary in order to qualify or
                          register all or part of the Preferred Securities in
                          any State in which the Sponsor has determined to
                          qualify or register such Preferred Securities for
                          sale;

                 (iii)    execute and file an application, prepared by the
                          Sponsor, to the New York Stock Exchange or any other
                          national stock exchange or the NASDAQ





                                       14
<PAGE>   20
                          National Market System for listing upon notice of
                          issuance of any Preferred Securities;

                 (iv)     execute and file with the Commission a registration
                          statement on Form 8-A, including any amendments
                          thereto, prepared by the Sponsor relating to the
                          registration of the Preferred Securities under
                          Section 12(b) of the Exchange Act; and

                 (v)      execute and enter into the Underwriting Agreement and
                          Pricing Agreement providing for the sale of the
                          Preferred Securities;

         (c)     to acquire the Notes with the proceeds of the sale of the
                 Preferred Securities and the Common Securities; provided,
                 however, that the Regular Trustees shall cause legal title to
                 the Notes to be held of record in the name of the Property
                 Trustee for the benefit of the Holders of the Preferred
                 Securities and the Holders of Common Securities;

         (d)     to give the Sponsor and the Property Trustee prompt written
                 notice of the occurrence of a Tax Event; provided that the
                 Regular Trustees shall consult with the Sponsor and the
                 Property Trustee before taking or refraining from taking any
                 Ministerial Action in relation to a Tax Event;

         (e)     to establish a record date with respect to all actions to be
                 taken hereunder that require a record date be established,
                 including and with respect to, for the purposes of Section
                 316(c) of the Trust Indenture Act, Distributions, voting
                 rights, redemptions and exchanges, and to issue relevant
                 notices to the Holders of Preferred Securities and Holders of
                 Common Securities as to such actions and applicable record
                 dates;

         (f)     to take all actions and perform such duties as may be required
                 of the Regular Trustees pursuant to the terms of the Trust
                 Securities;

         (g)     to bring or defend, pay, collect, compromise, arbitrate,
                 resort to legal action, or otherwise adjust claims or demands
                 of or against the Trust ("Legal Action"), unless pursuant to
                 Section 3.8(e), the Property Trustee has the exclusive power
                 to bring such Legal Action;

         (h)     to employ or otherwise engage employees and agents (who may be
                 designated as officers with titles) and





                                       15
<PAGE>   21
                 managers, contractors, advisors, and consultants and pay
                 reasonable compensation for such services;

         (i)     to cause the Trust to comply with the Trust's obligations
                 under the Trust Indenture Act;

         (j)     to give the certificate required by Section 314(a)(4) of the
                 Trust Indenture Act to the Property Trustee, which certificate
                 may be executed by a Regular Trustee;

         (k)     to incur expenses that are necessary or incidental to carry
                 out any of the purposes of the Trust;

         (l)     to act as, or appoint another Person to act as, registrar and
                 transfer agent for the Trust Securities;

         (m)     to give prompt written notice to the Holders of the Trust
                 Securities and the Property Trustee of any notice received
                 from the Note Issuer of its election (i) to defer payments of
                 interest on the Notes by extending the interest payment period
                 under the Indenture or, (ii) to extend the scheduled maturity
                 date on the Notes;

         (n)     to execute all documents or instruments, perform all duties
                 and powers, and do all things for and on behalf of the Trust
                 in all matters necessary or incidental to the foregoing;

         (o)     to take all action that may be necessary or appropriate for
                 the preservation and the continuation of the Trust's valid
                 existence, rights, franchises and privileges as a statutory
                 business trust under the laws of the State of Delaware and of
                 each other jurisdiction in which such existence is necessary
                 to protect the limited liability of the Holders of the Trust
                 Securities or to enable the Trust to effect the purposes for
                 which the Trust was created;

         (p)     to take any action, not inconsistent with this Declaration or
                 with applicable law, that the Regular Trustees determine in
                 their discretion to be necessary or desirable in carrying out
                 the activities of the Trust as set out in this Section 3.6,
                 including, but not limited to:

                 (i)      causing the Trust not to be deemed to be an
                          Investment Company required to be registered under
                          the Investment Company Act;





                                       16
<PAGE>   22
                 (ii)     causing the Trust to be classified for United States
                          federal income tax purposes as a grantor trust; and

                 (iii)    cooperating with the Note Issuer to ensure that the
                          Notes will be treated as indebtedness of the Note
                          Issuer for United States federal income tax purposes,

                 provided that such action does not adversely affect the
                 interests of Holders; and

         (q)     to take all action necessary to cause all applicable tax
                 returns and tax information reports that are required to be
                 filed with respect to the Trust to be duly prepared and filed
                 by the Regular Trustees, on behalf of the Trust.

         The Regular Trustees must exercise the powers set forth in this
Section 3.6 in a manner that is consistent with the purposes and functions of
the Trust set out in Section 3.3, and the Regular Trustees shall not take any
action that is inconsistent with the purposes and functions of the Trust set
forth in Section 3.3.

         Subject to this Section 3.6, the Regular Trustees shall have none of
the powers or the authority of the Property Trustee set forth in Section 3.8.

Section 3.7  Prohibition of Actions by the Trust and the Trustees.

         (a)     The Trust shall not, and the Trustees and the Property Trustee
                 shall not, engage in any activity other than as required or
                 authorized by this Declaration.  In particular, the Trust
                 shall not and the Trustees and the Property Trustee shall
                 cause the Trust not to:

                 (i)      invest any proceeds received by the Trust from
                          holding the Notes, but shall distribute all such
                          proceeds to Holders of Trust Securities pursuant to
                          the terms of this Declaration and of the Trust
                          Securities;

                 (ii)     acquire any assets other than as expressly provided
                          herein;

                 (iii)    possess Trust property for other than a Trust purpose;

                 (iv)     make any loans or incur any indebtedness other than
                          loans represented by the Notes;





                                       17
<PAGE>   23

                 (v)      possess any power or otherwise act in such a way as
                          to vary the Trust assets or the terms of the Trust
                          Securities in any way whatsoever;

                 (vi)     issue any securities or other evidences of beneficial
                          ownership of, or beneficial interest in, the Trust
                          other than the Trust Securities; or

                 (vii)    (A) direct the time, method and place of exercising
                          any trust or power conferred upon the Note Trustee
                          with respect to the Notes, (B) waive any past default
                          that is waivable under Section 513 of the Indenture,
                          (C) exercise any right to rescind or annul any
                          declaration that the principal of all the Notes shall
                          be due and payable or (D) consent to any amendment,
                          modification or termination of the Indenture or the
                          Notes where such consent shall be required unless the
                          Trust shall have received an opinion of counsel to
                          the effect that such modification will not cause more
                          than an insubstantial risk that for United States
                          federal income tax purposes the Trust will not be
                          classified as a grantor trust.

Section 3.8  Powers and Duties of the Property Trustee.

         (a)     The legal title to the Notes shall be owned by and held of
                 record in the name of the Property Trustee in trust for the
                 benefit of the Holders of the Trust Securities.  The right,
                 title and interest of the Property Trustee to the Notes shall
                 vest automatically in each Person who may hereafter be
                 appointed as Property Trustee in accordance with Section 5.6.
                 Such vesting and cessation of title shall be effective whether
                 or not conveyancing documents with regard to the Notes have
                 been executed and delivered.

         (b)     The Property Trustee shall not transfer its right, title and
                 interest in the Notes to the Regular Trustees or to the
                 Delaware Trustee (if the Property Trustee does not also act as
                 Delaware Trustee).

         (c)     The Property Trustee shall:

                 (i)      establish and maintain a segregated non-interest
                          bearing trust account (the "Property Trustee
                          Account") in the name of and under the exclusive
                          control of the Property Trustee on behalf of the
                          Holders of the Trust Securities and, upon the receipt
                          of payments of funds made in respect of the Notes
                          held by the Property Trustee, deposit such funds into
                          the Property Trustee Account and





                                       18
<PAGE>   24
                          make payments to the Holders of the Preferred
                          Securities and Holders of the Common Securities from
                          the Property Trustee Account in accordance with
                          Section 6.1.  Funds in the Property Trustee Account
                          shall be held uninvested until disbursed in accordance
                          with this Declaration.  The Property Trustee Account
                          shall be an account that is maintained with a banking
                          institution the rating on whose long term unsecured
                          indebtedness is at least equal to the rating assigned
                          to the Preferred Securities by a "nationally
                          recognized statistical rating organization", as that
                          term is defined for purposes of Rule 436(g)(2) under
                          the Securities Act;

                 (ii)     engage in such ministerial activities as shall be
                          necessary or appropriate to effect the redemption of
                          the Preferred Securities and the Common Securities to
                          the extent the Notes are redeemed or mature; and

                 (iii)    upon notice of distribution issued by the Regular
                          Trustees in accordance with the terms of the
                          Preferred Securities and forms of the Common
                          Securities, engage in such ministerial activities as
                          shall be necessary or appropriate to effect the
                          distribution of the Notes to Holders of Trust
                          Securities upon the occurrence of certain special
                          events (as may be defined in the terms of the Trust
                          Securities) arising from a change in law or a change
                          in legal interpretation or other specified
                          circumstances pursuant to the terms of the Trust
                          Securities.

         (d)     The Property Trustee shall take all actions and perform such
                 duties as may be specifically required of the Property Trustee
                 pursuant to the terms of the Trust Securities.

         (e)     The Property Trustee shall take any Legal Action which arises
                 out of or in connection with an Event of Default or the
                 Property Trustee's duties and obligations under this
                 Declaration or the Trust Indenture Act.

         (f)     The Property Trustee shall not resign as a trustee unless
                 either:

                 (i)      the Trust has been completely liquidated and the
                          proceeds of the liquidation distributed to the
                          Holders of Trust Securities pursuant to the terms of
                          the Trust Securities; or





                                       19
<PAGE>   25
                 (ii)     a Successor Property Trustee has been appointed and
                          has accepted that appointment in accordance with
                          Section 5.6.

         (g)     The Property Trustee shall have the legal power to exercise
                 all of the rights, powers and privileges of a holder of Notes
                 under the Indenture and, if an Event of Default occurs and is
                 continuing, the Property Trustee shall, for the benefit of
                 Holders of the Trust Securities, enforce its rights as holder
                 of the Notes subject to the rights of the Holders pursuant to
                 the terms of such Trust Securities.

         (h)     The Property Trustee may authorize one or more Persons (each,
                 a "Paying Agent") to pay Distributions, redemption payments or
                 liquidation payments on behalf of the Trust with respect to
                 all Trust Securities and any such Paying Agent shall comply
                 with Section 317(b) of the Trust Indenture Act.  Any Paying
                 Agent may be removed by the Property Trustee at any time and a
                 successor Paying Agent or additional Paying Agents may be
                 appointed at any time by the Property Trustee.

         (i)     Subject to this Section 3.8, the Property Trustee shall have
                 none of the duties, liabilities, powers or the authority of
                 the Regular Trustees set forth in Section 3.6.

         The Property Trustee must exercise the powers set forth in this
Section 3.8 in a manner that is consistent with the purposes and functions of
the Trust set out in Section 3.3, and the Property Trustee shall not take any
action that is inconsistent with the purposes and functions of the Trust set
out in Section 3.3.

Section 3.9  Certain Duties and Responsibilities of the Property Trustee.

         (a)     The Property Trustee, before the occurrence of any Event of
                 Default and after the curing of all Events of Default that may
                 have occurred, shall undertake to perform only such duties as
                 are specifically set forth in this Declaration and no implied
                 covenants shall be read into this Declaration against the
                 Property Trustee.  In case an Event of Default has occurred
                 (that has not been cured or waived pursuant to Section 2.6),
                 the Property Trustee shall exercise such of the rights and
                 powers vested in it by this Declaration, and use the same
                 degree of care and skill in their exercise, as a prudent
                 person would exercise or use under the circumstances in the
                 conduct of his or her own affairs.





                                       20
<PAGE>   26

         (b)     No provision of this Declaration shall be construed to relieve
                 the Property Trustee from liability for its own negligent
                 action, its own negligent failure to act, or its own willful
                 misconduct, except that:

                 (i)      prior to the occurrence of an Event of Default and
                          after the curing or waiving of all such Events of
                          Default that may have occurred:

                          (A)     the duties and obligations of the Property
                                  Trustee shall be determined solely by the
                                  express provisions of this Declaration and
                                  the Property Trustee shall not be liable
                                  except for the performance of such duties and
                                  obligations as are specifically set forth in
                                  this Declaration, and no implied covenants or
                                  obligations shall be read into this
                                  Declaration against the Property Trustee; and

                          (B)     in the absence of bad faith on the part of
                                  the Property Trustee, the Property Trustee
                                  may conclusively rely, as to the truth of the
                                  statements and the correctness of the
                                  opinions expressed therein, upon any
                                  certificates or opinions furnished to the
                                  Property Trustee and conforming to the
                                  requirements of this Declaration; but in the
                                  case of any such certificates or opinions
                                  that by any provision hereof are specifically
                                  required to be furnished to the Property
                                  Trustee, the Property Trustee shall be under
                                  a duty to examine the same to determine
                                  whether or not they conform to the
                                  requirements of this Declaration;

                 (ii)     the Property Trustee shall not be liable for any
                          error of judgment made in good faith by a Responsible
                          Officer of the Property Trustee, unless it shall be
                          proved that the Property Trustee was negligent in
                          ascertaining the pertinent facts;

                 (iii)    the Property Trustee shall not be liable with respect
                          to any action taken or omitted to be taken by it in
                          good faith in accordance with the direction of the
                          Holders of not less than a Majority in liquidation
                          amount of the Trust Securities at the time
                          outstanding relating to the time, method and place of
                          conducting any proceeding for any remedy available to
                          the Property Trustee, or exercising any trust or
                          power





                                       21
<PAGE>   27
                          conferred upon the Property Trustee under this
                          Declaration;

                 (iv)     no provision of this Declaration shall require the
                          Property Trustee to expend or risk its own funds or
                          otherwise incur personal financial liability in the
                          performance of any of its duties or in the exercise
                          of any of its rights or powers, if it shall have
                          reasonable grounds for believing that the repayment
                          of such funds or liability is not reasonably assured
                          to it under the terms of this Declaration or adequate
                          indemnity against such risk or liability is not
                          reasonably assured to it;

                 (v)      the Property Trustee's sole duty with respect to the
                          custody, safekeeping and physical preservation of the
                          Notes and the Property Trustee Account shall be to
                          deal with such property in a similar manner as the
                          Property Trustee deals with similar property for its
                          own account, subject to the protections and
                          limitations on liability afforded to the Property
                          Trustee under this Declaration and the Trust
                          Indenture Act;

                 (vi)     the Property Trustee shall have no duty or liability
                          for or with respect to the value, genuineness,
                          existence or sufficiency of the Notes or the payment
                          of any taxes or assessments levied thereon or in
                          connection therewith;

                 (vii)    the Property Trustee shall not be liable for any
                          interest on any money received by it except as it may
                          otherwise agree with the Sponsor.  Money held by the
                          Property Trustee need not be segregated from other
                          funds held by it except in relation to the Property
                          Trustee Account maintained by the Property Trustee
                          pursuant to Section 3.8(c)(i) and except to the
                          extent otherwise required by law; and

                 (viii)   the Property Trustee shall not be responsible for
                          monitoring the compliance by the Regular Trustees or
                          the Sponsor with their respective duties under this
                          Declaration, nor shall the Property Trustee be liable
                          for the default or misconduct of the Regular Trustees
                          or the Sponsor.

Section 3.10 Certain Rights of Property Trustee.

         (a)     Subject to the provisions of Section 3.9:





                                       22
<PAGE>   28
                 (i)      the Property Trustee may rely and shall be fully
                          protected in acting or refraining from acting upon any
                          resolution, certificate, statement, instrument,
                          opinion, report, notice, request, direction, consent,
                          order, bond, debenture, note, other evidence of
                          indebtedness or other paper or document believed by it
                          to be genuine and to have been signed, sent or
                          presented by the proper party or parties;

                 (ii)     any direction or act of the Sponsor or the Regular
                          Trustees contemplated by this Declaration shall be
                          sufficiently evidenced by a Direction or an Officers'
                          Certificate;

                 (iii)    whenever in the administration of this Declaration,
                          the Property Trustee shall deem it desirable that a
                          matter be proved or established before taking,
                          suffering or omitting any action hereunder, the
                          Property Trustee (unless other evidence is herein
                          specifically prescribed) may, in the absence of bad
                          faith on its part request and rely upon an Officers'
                          Certificate which, upon receipt of such request,
                          shall be promptly delivered by the Sponsor or the
                          Regular Trustees;

                 (iv)     the Property Trustee shall have no duty to see to any
                          recording, filing or registration of any instrument
                          (including any financing or continuation statement or
                          any filing under tax or securities laws) (or any
                          rerecording, refiling or registration thereof);

                 (v)      the Property Trustee may consult with counsel or
                          other experts and the advice or opinion of such
                          counsel and experts with respect to legal matters or
                          advice within the scope of such experts' area of
                          expertise shall be full and complete authorization
                          and protection in respect of any action taken,
                          suffered or omitted by it hereunder in good faith and
                          in accordance with such advice or opinion.  Such
                          counsel may be counsel to the Sponsor or any of its
                          Affiliates, and may include any of its employees.
                          The Property Trustee shall have the right at any time
                          to seek instructions concerning the administration of
                          this Declaration from any court of competent
                          jurisdiction;

                 (vi)     the Property Trustee shall be under no obligation to
                          exercise any of the rights or powers vested in it by
                          this Declaration at the request or direction of any
                          Holder, unless such Holder shall have





                                       23
<PAGE>   29
                          provided to the Property Trustee security and
                          indemnity, acceptable to the Property Trustee, against
                          the costs, expenses (including attorneys' fees and
                          expenses) and liabilities that might be incurred by it
                          in complying with such request or direction, including
                          such reasonable advances as may be requested by the
                          Property Trustee provided, that, nothing contained in
                          this Section 3.10(a)(vi) shall be taken to relieve the
                          Property Trustee, upon the occurrence of an Event of
                          Default, of its obligation to exercise the rights and
                          powers vested in it by this Declaration;

                 (vii)    the Property Trustee shall not be bound to make any
                          investigation into the facts or matters stated in any
                          resolution, certificate, statement, instrument,
                          opinion, report, notice, request, direction, consent,
                          order, bond, debenture, note, other evidence of
                          indebtedness or other paper or document, but the
                          Property Trustee, in its discretion, may make such
                          further inquiry or investigation into such facts or
                          matters as it may see fit;

                 (viii)   the Property Trustee may execute any of the trusts or
                          powers hereunder or perform any duties hereunder
                          either directly or by or through agents or attorneys
                          and the Property Trustee shall not be responsible for
                          any misconduct or negligence on the part of any agent
                          or attorney appointed with due care by it hereunder;

                 (ix)     any action taken by the Property Trustee or its
                          agents hereunder shall bind the Trust and the Holders
                          of the Trust Securities, and the signature of the
                          Property Trustee or its agents alone shall be
                          sufficient and effective to perform any such action
                          and no third party shall be required to inquire as to
                          the authority of the Property Trustee to so act or as
                          to its compliance with any of the terms and
                          provisions of this Declaration, both of which shall
                          be conclusively evidenced by the Property Trustee's
                          or its agent's taking such action;

                 (x)      whenever in the administration of this Declaration
                          the Property Trustee shall deem it desirable to
                          receive instructions with respect to enforcing any
                          remedy or right or taking any other action hereunder
                          the Property Trustee (i) may request instructions
                          from the Holders of the Trust Securities which
                          instructions may only be given by





                                       24
<PAGE>   30
                          the Holders of the same proportion in liquidation
                          amount of the Trust Securities as would be entitled to
                          direct the Property Trustee under the terms of the
                          Trust Securities in respect of such remedy, right or
                          action, (ii) may refrain from enforcing such remedy or
                          right or taking such other action until such
                          instructions are received, and (iii) shall be
                          protected in acting in accordance with such
                          instructions; and

                 (xi)     except as otherwise expressly provided by this
                          Declaration, the Property Trustee shall not be under
                          any obligation to take any action that is
                          discretionary under the provisions of this
                          Declaration.

         (b)     No provision of this Declaration shall be deemed to impose any
                 duty or obligation on the Property Trustee to perform any act
                 or acts or exercise any right, power, duty or obligation
                 conferred or imposed on it, in any jurisdiction in which it
                 shall be illegal, or in which the Property Trustee shall be
                 unqualified or incompetent in accordance with applicable law,
                 to perform any such act or acts, or to exercise any such
                 right, power, duty or obligation.  No permissive power or,
                 authority available to the Property Trustee shall be construed
                 to be a duty.

Section 3.11 Delaware Trustee.

                 Notwithstanding any other provision of this Declaration other
than Sections 5.2 and 8.1(b), the Delaware Trustee shall not be entitled to
exercise any powers, nor shall the Delaware Trustee have any of the duties and
responsibilities of the Regular Trustees or the Property Trustee described in
this Declaration.  Except as set forth in Sections 5.2 and 8.1(b), the Delaware
Trustee shall be a Trustee for the sole and limited purpose of fulfilling the
requirements of Section 3807 of the Business Trust Act.  The Delaware Trustee
shall be entitled to the benefit of all of the immunities and indemnities that
the Property Trustee is entitled to under the Declaration.

Section 3.12 Execution of Documents.

                 Unless otherwise determined by the Regular Trustees, and
except as otherwise required by the Business Trust Act, a majority of or, if
there are only two, both of the Regular Trustees are authorized to execute on
behalf of the Trust any documents that the Regular Trustees have the power and
authority to execute pursuant to Section 3.6; provided that, any listing
application prepared by the Sponsor referred to in Section 3.6(b)(iii) may be
executed by one Regular Trustee.





                                       25
<PAGE>   31

Section 3.13 Not Responsible for Recitals or Issuance of Trust Securities.

                 The recitals contained in this Declaration and the Trust
Securities shall be taken as the statements of the Sponsor, and the Trustees do
not assume any responsibility for their correctness.  The Trustees make no
representations as to the value or condition of the property of the Trust or
any part thereof.  The Trustees make no representations as to the validity or
sufficiency of this Declaration or the Trust Securities.

Section 3.14 Duration of Trust.

                 The Trust, unless terminated pursuant to the provisions of
Article VIII hereof, shall have existence for 55 years from the Closing Date.

Section 3.15 Mergers.

         (a)     The Trust may not consolidate, amalgamate, merge with or into,
                 or be replaced by, or convey, transfer or lease its properties
                 and assets substantially as an entirety to any corporation or
                 other body, except as described in Section 3.15(b) and (c).

         (b)     The Trust may, with the consent of a majority of the Regular
                 Trustees and without the consent of the Holders of the Trust
                 Securities, the Delaware Trustee or the Property Trustee,
                 consolidate, amalgamate, merge with or into, or be replaced by
                 a trust organized as such under the laws of any State;
                 provided that:

                 (i)      such successor entity (the "Successor Entity") either:

                          (A)     expressly assumes all of the obligations of
                                  the Trust under the Trust Securities; or

                          (B)     substitutes for the Preferred Securities
                                  other securities having substantially the
                                  same terms as the Preferred Securities (the
                                  "Successor Securities") so long as the
                                  Successor Securities rank the same as the
                                  Preferred Securities rank with respect to
                                  Distributions and payments upon liquidation,
                                  redemption and maturity;

                 (ii)     the Note Issuer expressly acknowledges a trustee of
                          the Successor Entity that possesses the same powers
                          and duties as the Property Trustee as the Holder of
                          the Notes;





                                       26
<PAGE>   32

                 (iii)    the Preferred Securities or any Successor Securities
                          are listed, or any Successor Securities will be
                          listed upon notification of issuance, on any national
                          securities exchange, the NASDAQ National Market
                          System or other organization on which the Preferred
                          Securities are then listed;

                 (iv)     such merger, consolidation, amalgamation or
                          replacement does not cause the Preferred Securities
                          (including any Successor Securities) to be downgraded
                          by any nationally recognized statistical rating
                          organization;

                 (v)      such merger, consolidation, amalgamation or
                          replacement does not adversely affect the rights,
                          preferences and privileges of the Holders of the
                          Trust Securities (including any Successor Securities)
                          in any material respect;

                 (vi)     such Successor Entity has a purpose identical to that
                          of the Trust;

                 (vii)    prior to such merger, consolidation, amalgamation or
                          replacement, the Sponsor has received an opinion of a
                          nationally recognized independent counsel to the
                          Trust experienced in such matters to the effect that:

                          (A)     such merger, consolidation, amalgamation or
                                  replacement does not adversely affect the
                                  rights, preferences and privileges of the
                                  Holders of the Trust Securities (including
                                  any Successor Securities) in any material
                                  respect; and

                          (B)     following such merger, consolidation,
                                  amalgamation or replacement, neither the
                                  Trust nor the Successor Entity will be
                                  required to register as an Investment
                                  Company; and

                 (viii)   the Sponsor guarantees the obligations of such
                          Successor Entity under the Successor Securities at
                          least to the extent provided by the Preferred
                          Securities Guarantee.

         (c)     Notwithstanding Section 3.15(b), the Trust shall, except with
                 the consent of Holders of 100% in liquidation amount of the
                 Trust Securities, not consolidate, amalgamate, merge with or
                 into, or be replaced by any other entity or permit any other
                 entity to consolidate, amalgamate, merge with or into, or





                                       27
<PAGE>   33
                 replace it if such consolidation, amalgamation, merger or
                 replacement would cause the Trust or Successor Entity not to be
                 classified for United States federal income tax purposes as a
                 grantor trust.


                                   ARTICLE IV
                                    Sponsor

Section 4.1  Sponsor's Purchase of Common Securities.

                 On the Closing Date the Sponsor will purchase all the Common
Securities issued by the Trust, in an amount equal to 3% of the capital of the
Trust, at the same time as the Preferred Securities are sold.

Section 4.2  Responsibilities of the Sponsor.

                 In connection with the issue and sale of the Preferred
Securities, the Sponsor shall have the exclusive right and responsibility to
engage in the following activities:

         (a)     to prepare for filing by the Trust with the Commission a
                 registration statement on Form S-3 in relation to the
                 Preferred Securities, including any amendments thereto;

         (b)     to determine the States in which to take appropriate action to
                 qualify or register for sale all or part of the Preferred
                 Securities and to do any and all such acts, other than actions
                 which must be taken by the Trust, and advise the Trust of
                 actions it must take, and prepare for execution and filing any
                 documents to be executed and filed by the Trust, as the
                 Sponsor deems necessary or advisable in order to comply with
                 the applicable laws of any such States;

         (c)     to prepare for filing by the Trust an application to the New
                 York Stock Exchange or any other national stock exchange or
                 the NASDAQ National Market System for listing upon notice of
                 issuance of any Preferred Securities;

         (d)     to prepare for filing by the Trust with the Commission a
                 registration statement on Form 8-A relating to the
                 registration of the Preferred Securities under Section 12(b)
                 of the Exchange Act, including any amendments thereto; and

         (e)     to negotiate the terms of the Underwriting Agreement and
                 Pricing Agreement providing for the sale of the Preferred
                 Securities.





                                       28
<PAGE>   34


                                   ARTICLE V
                                    Trustees

Section 5.1  Number of Trustees.

                 The number of Trustees shall initially be three (3), and:

         (a)     at any time before the issuance of any Trust Securities, the
                 Sponsor may, by written instrument, increase or decrease the
                 number of Trustees; and

         (b)     after the issuance of any Trust Securities, the number of
                 Trustees may be increased or decreased by vote of the Holders
                 of a Majority in liquidation amount of the Common Securities
                 voting as a class at a meeting of the Holders of the Common
                 Securities, provided that in any case, the number of Trustees
                 shall be at least three (3) and a majority of the Trustees
                 shall be Regular Trustees.

Section 5.2  Delaware Trustee.

                 If required by the Business Trust Act, one Trustee (the
"Delaware Trustee") shall be:

         (a)     a natural person who is a resident of the State of Delaware; or

         (b)     if not a natural person, an entity which has its principal
                 place of business in the State of Delaware, and otherwise
                 meets the requirements of applicable law,

provided that, if the Property Trustee has its principal place of business in
the State of Delaware and otherwise meets the requirements of applicable law,
then the Property Trustee shall also be the Delaware Trustee and Section 3.11
shall have no application.  Except as otherwise provided, the Delaware
Trustee's sole duty shall be to, upon the request of the other Trustees or the
Sponsor, execute any documents and maintain custody of any records required to
form, maintain the existence of, or dissolve, the Trust under the Business
Trust Act.

Section 5.3  Property Trustee; Eligibility.

         (a)     There shall at all times be one Trustee which shall act as
                 Property Trustee which shall:

                 (i)      not be an Affiliate of the Sponsor;





                                       29
<PAGE>   35
                 (ii)     be a corporation organized and doing business under
                          the laws of the United States of America or any State
                          or Territory thereof or of the District of Columbia,
                          or a corporation or Person permitted by the Commission
                          to act as an institutional trustee under the Trust
                          Indenture Act, authorized under such laws to exercise
                          corporate trust powers, having a combined capital and
                          surplus of at least 50 million U.S. dollars
                          ($50,000,000), and subject to supervision or
                          examination by Federal, state, Territorial or District
                          of Columbia authority.  If such corporation publishes
                          reports of condition at least annually, pursuant to
                          law or to the requirements of the supervising or
                          examining authority referred to above, then for the
                          purposes of this Section 5.3(a)(ii), the combined
                          capital and surplus of such corporation shall be
                          deemed to be its combined capital and surplus as set
                          forth in its most recent report of condition so
                          published.

         (b)     If at any time the Property Trustee shall cease to be eligible
                 to so act under Section 5.3(a), the Property Trustee shall
                 immediately resign in the manner and with the effect set forth
                 in Section 5.6(c).

         (c)     If the Property Trustee has or shall acquire any "conflicting
                 interest" within the meaning of Section 310(b) of the Trust
                 Indenture Act, the Property Trustee and the Holder of the
                 Common Securities (as if it were the obligor referred to in
                 Section 310(b) of the Trust Indenture Act) shall in all
                 respects comply with the provisions of Section 310(b) of the
                 Trust Indenture Act.

         (d)     The Preferred Securities Guarantee shall be deemed to be
                 specifically described in this Declaration for purposes of
                 clause (i) of the first provision contained in Section 310(b)
                 of the Trust Indenture Act.

Section 5.4  Qualifications of Regular Trustees and Delaware Trustee Generally.

                 Each Regular Trustee and the Delaware Trustee (unless the
Property Trustee also acts as Delaware Trustee) shall be either a natural
person who is at least 21 years of age or a legal entity that shall act through
one or more Authorized Officers.  Each of the Regular Trustees shall be an
employee or officer of the Sponsor or otherwise be affiliated with the Sponsor.





                                       30
<PAGE>   36
Section 5.5  Initial Trustees.

                 The initial Regular Trustees shall be:

                 George C. Biehl
                 5241 Spring Mountain Road
                 Las Vegas, Nevada 89102

                 Jeffrey W. Shaw
                 5241 Spring Mountain Road
                 Las Vegas, Nevada 89102

         The initial Delaware Trustee shall be:

                 Wilmington Trust Company
                 1100 N. Market Street
                 Wilmington,  Delaware  19890

         The Initial Property Trustee shall be:

                 Harris Trust and Savings Bank
                 311 West Monroe Street, 12th Floor
                 Chicago, Illinois 60606
                 Attention:  Indenture Trust Administration

Section 5.6  Appointment, Removal and Resignation of Trustees.

         (a)     Subject to Section 5.6(b), Trustees may be appointed or
                 removed without cause at any time:

                 (i)      until the issuance of any securities, by written
                          instrument executed by the Sponsor; and

                 (ii)     after the issuance of any Trust Securities by vote of
                          the Holders of a Majority in liquidation amount of
                          the Common Securities voting as a class at a meeting
                          of the Holders of the Common Securities; and

         (b)     (i)      The Trustee that acts as Property Trustee shall not
                          be removed in accordance with Section 5.6(a) until a
                          Successor Property Trustee has been appointed and has
                          accepted such appointment by written instrument
                          executed by such Successor Property Trustee and
                          delivered to the Regular Trustees and the Sponsor;
                          and

                 (ii)     the Trustee that acts as Delaware Trustee shall not
                          be removed in accordance with this Section 5.6(a)
                          until a successor Trustee possessing the
                          qualifications to act as Delaware Trustee under
                          Sections 5.2 and 5.4 (a "Successor





                                       31
<PAGE>   37
                          Delaware Trustee") has been appointed and has accepted
                          such appointment by written instrument executed by
                          such Successor Delaware Trustee and delivered to the
                          Regular Trustees and the Sponsor.

         (c)     A Trustee appointed to office shall hold office until his
                 successor shall have been appointed or until his death,
                 removal or resignation.  Any Trustee may resign from office
                 (without need for prior or subsequent accounting) by any
                 instrument in writing signed by the Trustee and delivered to
                 the Sponsor and the Trust, which resignation shall take effect
                 upon such delivery or upon such later date as is specified
                 therein; provided, however, that:

                 (i)      No such resignation of the Trustee that acts as the
                          Property Trustee shall be effective:

                          (A)     until a Successor Property Trustee has been
                                  appointed and has accepted such appointment
                                  by instrument executed by such Successor
                                  Property Trustee and delivered to the Trust,
                                  the Sponsor and the resigning Property
                                  Trustee; or

                          (B)     until the assets of the Trust have been
                                  completely liquidated and the proceeds
                                  thereof distributed to the Holders of the
                                  Trust Securities; and

                 (ii)     no such resignation of the Trustee that acts as the
                          Delaware Trustee shall be effective until a Successor
                          Delaware Trustee has been appointed and has accepted
                          such appointment by instrument executed by such
                          Successor Delaware Trustee and delivered to the
                          Trust, the Sponsor and the resigning Delaware
                          Trustee.

         (d)     The Holders of the Common Securities shall use their best
                 efforts to promptly appoint a Successor Delaware Trustee or
                 Successor Property Trustee, as the case may be, as the
                 Property Trustee or the Delaware Trustee if the resigning
                 Property Trustee or Delaware Trustee delivers an instrument of
                 resignation in accordance with this Section 5.6.

         (e)     If no Successor Property Trustee or Successor Delaware Trustee
                 shall have been appointed and accepted appointment as provided
                 in this Section 5.6 within 60 days after delivery to the
                 Sponsor and the Trust of an instrument of resignation, the
                 resigning Property Trustee or Delaware Trustee, as applicable,
                 may





                                       32
<PAGE>   38
                 petition any court of competent jurisdiction for appointment of
                 a Successor Property Trustee or Successor Delaware Trustee.
                 Such court may thereupon, after prescribing such notice, if
                 any, as it may deem proper, appoint a Successor Property
                 Trustee or Successor Delaware Trustee, as the case may be.

Section 5.7  Vacancies among Trustees.

                 If a Trustee ceases to hold office for any reason and the
number of Trustees is not reduced pursuant to Section 5.1, or if the number of
Trustees is increased pursuant to Section 5.1, a vacancy shall occur.  A
resolution certifying the existence of such vacancy by a majority of the
Regular Trustees shall be conclusive evidence of the existence of such vacancy.
The vacancy shall be filled with a Trustee appointed in accordance with Section
5.6.

Section 5.8  Effect of Vacancies.

                 The death, resignation, retirement, removal, bankruptcy,
dissolution, liquidation, incompetence or incapacity to perform the duties of a
Trustee shall not operate to annul the Trust.  Whenever a vacancy in the number
of Regular Trustees shall occur, until such vacancy is filled by the
appointment of a Regular Trustee in accordance with Section 5.6, the Regular
Trustees in office, regardless of their number, shall have all the powers
granted to the Regular Trustees and shall discharge all the duties imposed upon
the Regular Trustees by this Declaration.

Section 5.9  Meetings.

                 Meetings of the Regular Trustees shall be held from time to
time upon the call of any Regular Trustee.  Regular meetings of the Regular
Trustees may be held at a time and place fixed by resolution of the Regular
Trustees.  Notice of any in- person meetings of the Regular Trustees shall be
hand delivered or otherwise delivered in writing (including by facsimile, with
a hard copy by overnight courier) not less than 48 hours before such meeting.
Notice of any telephonic meetings of the Regular Trustees or any committee
thereof shall be hand delivered or otherwise delivered in writing (including by
facsimile, with a hard copy by overnight courier) not less than 24 hours before
a meeting.  Notices shall contain a brief statement of the time, place and
anticipated purposes of the meeting.  The presence (whether in person or by
telephone) of a Regular Trustee at a meeting shall constitute a waiver of
notice of such meeting except where a Regular Trustee attends a meeting for the
express purpose of objecting to the transaction of any activity on the ground
that the meeting has not been lawfully called or convened.  Unless provided
otherwise in this Declaration, any action of the





                                       33
<PAGE>   39
Regular Trustees may be taken at a meeting by vote of a majority of the Regular
Trustees present (whether in person or by telephone) and eligible to vote with
respect to such matter, provided that a Quorum is present, or without a meeting
by the unanimous written consent of the Regular Trustees.

Section 5.10 Delegation of Power.

         (a)     Any Regular Trustee may, by power of attorney consistent with
                 applicable law, delegate to any other natural person over the
                 age of 21 his or her power for the purpose of executing any
                 documents contemplated in Section 3.6, including any
                 registration statement or amendment thereto filed with the
                 Commission, or making any other governmental filing; and

         (b)     the Regular Trustees shall have power to delegate from time to
                 time to such of their number or to officers of the Trust the
                 doing of such things and the execution of such instruments
                 either in the name of the Trust or the names of the Regular
                 Trustees or otherwise as the Regular Trustees may deem
                 expedient, to the extent such delegation is not prohibited by
                 applicable law or contrary to the provisions of the Trust, as
                 set forth herein.


                                   ARTICLE VI
                                 Distributions

Section 6.1  Distributions.

                 Holders shall receive Distributions in accordance with the
applicable terms of the relevant Holder's Trust Securities.  Distributions
shall be made on the Preferred Securities and the Common Securities in
accordance with the preferences set forth in their respective terms.  If and to
the extent that the Note Issuer makes a payment of interest (including Deferred
Interest (as defined in the Indenture)), premium and principal on the Notes
held by the Property Trustee (the amount of any such payment being a "Payment
Amount"), the Property Trustee shall and is directed, to the extent funds are
available for that purpose, to make a distribution (a "Distribution") of the
Payment Amount to Holders.





                                       34
<PAGE>   40
                                  ARTICLE VII
                          Issuance of Trust Securities

Section 7.1  General Provisions Regarding Trust Securities.

         (a)     The Regular Trustees shall on behalf of the Trust issue one
                 class of preferred securities representing undivided
                 beneficial interests in the assets of the Trust having such
                 terms as are set forth in Exhibit A and incorporated herein by
                 reference (the "Preferred Securities") and one class of common
                 securities representing undivided beneficial interests in the
                 assets of the Trust having such terms as are set forth in
                 Exhibit A (the "Common Securities").  The Trust shall have no
                 securities or other interests in the assets of the Trust other
                 than the Preferred Securities and the Common Securities.

         (b)     The Certificates shall be signed on behalf of the Trust by the
                 Regular Trustees (or if there are more than two Regular
                 Trustees by any two of the Regular Trustees).  Such signatures
                 may be the manual or facsimile signatures of the present or
                 any future Regular Trustee.  Typographical and other minor
                 errors or defects in any such reproduction of any such
                 signature shall not affect the validity of any Certificate.
                 In case any Regular Trustee of the Trust who shall have signed
                 any of the Trust Securities shall cease to be such Regular
                 Trustee before the Certificates so signed shall be delivered
                 by the Trust, such Certificates nevertheless may be delivered
                 as though the person who signed such Certificates had not
                 ceased to be such Regular Trustee; and any Certificate may be
                 signed on behalf of the Trust by such persons who, at the
                 actual date of execution of such Trust Security, shall be the
                 Regular Trustees of the Trust, although at the date of the
                 execution and delivery of the Declaration any such person was
                 not such a Regular Trustee.  Certificates shall be printed,
                 lithographed or engraved or may be produced in any other
                 manner as is reasonably acceptable to the Regular Trustees, as
                 evidenced by their execution thereof, and may have such
                 letters, numbers or other marks or identification or
                 designation and such legends or endorsements as the Regular
                 Trustees may deem appropriate, or as may be required to comply
                 with any law or with any rule or regulation of any stock
                 exchange on which Trust Securities may be listed, or to
                 conform to usage.

         (c)     The consideration received by the Trustee for the issuance of
                 the Trust Securities shall constitute a





                                       35
<PAGE>   41
                 contribution to the capital of the Trust and shall not
                 constitute a loan to the Trust.

         (d)     Upon issuance of the Trust Securities as provided in this
                 Declaration, the Trust Securities so issued shall be deemed to
                 be validly issued, fully paid and non-assessable.

         (e)     Every Person, by virtue of having become a Holder or a
                 Preferred Security Beneficial Owner in accordance with the
                 terms of this Declaration, shall be deemed to have expressly
                 assented and agreed to the terms of, and shall be bound by,
                 this Declaration.


                                  ARTICLE VIII
                                  Termination

 Section 8.1  Termination of Trust.

         (a)     The Trust shall terminate on the earlier of _________ [55
                 years after issuance of the Notes] or:

                 (i)      upon the bankruptcy of the Holder of the Common
                          Securities or the Sponsor;

                 (ii)     upon the filing of a certificate of dissolution or
                          its equivalent with respect to the Holder of the
                          Common Securities or the Sponsor; the filing of a
                          certificate of cancellation with respect to the Trust
                          or the revocation of the Holder of the Common
                          Securities or the Sponsor's charter and the
                          expiration of 90 days after the date of revocation
                          without a reinstatement thereof;

                 (iii)    upon the entry of a decree of judicial dissolution of
                          the Holder of the Common Securities, the Sponsor or
                          the Trust;

                 (iv)     when all of the Trust Securities shall have been
                          called for redemption and the amounts necessary for
                          redemption thereof shall have been paid to the
                          Holders in accordance with the terms of the Trust
                          Securities;

                 (v)      upon the occurrence and continuation of a Tax Event
                          pursuant to which the Trust shall have been dissolved
                          in accordance with the terms of the Trust Securities
                          and all of the Notes endorsed thereon shall have been
                          distributed to the Holders of Trust Securities in
                          exchange for all of the Trust Securities; or





                                       36
<PAGE>   42

                 (vi)     before the issuance of any Trust Securities, with the
                          consent of all of the Regular Trustees and the
                          Sponsor.

         (b)     As soon as is practicable after the occurrence of an event
                 referred to in Section 8.1(a), the Delaware Trustee shall file
                 a certificate of cancellation with the Secretary of State of
                 the State of Delaware.

         (c)     The provisions of Section 3.9 and Article X shall survive the
                 termination of the Trust.


                                   ARTICLE IX
                              Transfer of Interest

Section 9.1  Transfer of Trust Securities.

         (a)     Trust Securities may only be transferred, in whole or in part,
                 in accordance with the terms and conditions set forth in this
                 Declaration and in the terms of the Trust Securities.  Any
                 transfer or purported transfer of any Trust Security not made
                 in accordance with this Declaration shall be null and void.

         (b)     Subject to this Article IX, Preferred Securities shall be
                 freely transferable.

         (c)     Subject to this Article IX, the Sponsor and any Related Party
                 may only transfer Common Securities to the Sponsor or a
                 Related Party of the Sponsor; provided that, any such transfer
                 is subject to the conditions precedent that the transferor
                 obtain the written opinion of nationally recognized
                 independent counsel experienced in such matters that such
                 transfer would not cause more than an insubstantial risk that:

                 (i)      the Trust would not be classified for United States
                          federal income tax purposes as a grantor trust; and

                 (ii)     the Trust would be an Investment Company or the
                          transferee would become an Investment Company.

Section 9.2  Transfer of Certificates.

                 The Regular Trustees shall provide for the registration of
Certificates and of transfers of Certificates, which will be effected without
charge but only upon payment (with such indemnity as the Regular Trustees may
require) in respect of any tax or other governmental charges that may be
imposed in relation to it.  Upon surrender for registration of transfer of any





                                       37
<PAGE>   43
Certificate, the Regular Trustees shall cause one or more new Certificates to be
issued in the name of the designated transferee or transferees.  Every
Certificate surrendered for registration of transfer shall be accompanied by a
written instrument of transfer in form satisfactory to the Regular Trustees duly
executed by the Holder or such Holder's attorney duly authorized in writing.
Each Certificate surrendered for registration of transfer shall be canceled by
the Regular Trustees.  A transferee of a Certificate shall be entitled to the
rights and subject to the obligations of a Holder hereunder upon the receipt by
such transferee of a Certificate.  By acceptance of a Certificate, each
transferee shall be deemed to have agreed to be bound by this Declaration and
the documents incorporated by reference herein.

Section 9.3  Deemed Trust Security Holders.

                 The Trustees may treat the Person in whose name any
Certificate shall be registered on the books and records of the Trust as the
sole holder of such Certificate and of the Trust Securities represented by such
Certificate for purposes of receiving Distributions and for all other purposes
whatsoever and, accordingly, shall not be bound to recognize any equitable or
other claim to or interest in such Certificate or in the Trust Securities
represented by such Certificate on the part of any Person, whether or not the
Trust shall have actual or other notice thereof.

Section 9.4  Book Entry Interests.

                 Unless otherwise specified in the terms of the Preferred
Securities, the Preferred Securities Certificates, on original issuance, will
be issued in the form of one or more, fully registered, global Preferred
Security Certificates (each, a "Global Certificate"), to be delivered to DTC,
the initial Depositary, by, or on behalf of, the Trust.  Such Global
Certificates shall initially be registered on the books and records of the
Trust in the name of Cede & Co., the nominee of DTC, and no Preferred Security
Beneficial Owner will receive a definitive Preferred Security Certificate
representing such Preferred Security Beneficial Owner's interests in such
Global Certificates, except as provided in Section 9.7.  Unless and until
definitive, fully registered Preferred Security Certificates (the "Definitive
Preferred Security Certificates") have been issued to the Preferred Security
Beneficial Owners pursuant to Section 9.7:

         (a)     the provisions of this Section 9.4 shall be in full force and
                 effect;

         (b)     the Trust and the Trustees shall be entitled to deal with the
                 Depositary for all purposes of this





                                       38
<PAGE>   44
                 Declaration (including the payment of Distributions on the
                 Global Certificates and receiving approvals, votes or consents
                 hereunder) as the Holder of the Preferred Securities and the
                 sole holder of the Global Certificates and shall have no
                 obligation to the Preferred Security Beneficial Owners;

         (c)     to the extent that the provisions of this Section 9.4 conflict
                 with any other provisions of the Declaration, the provisions
                 of this Section 9.4 shall control; and

         (d)     the rights of the Preferred Security Beneficial Owners shall
                 be exercised only through the Depositary and shall be limited
                 to those established by law and agreements between such
                 Preferred Security Beneficial Owners and the Depositary and/or
                 the Depositary Participants and receive and transmit payments
                 of Distributions on the Global Certificates to such Depositary
                 Participants.  DTC will make book entry transfers among the
                 Depositary Participants.

Section 9.5  Notices to Depositary.

                 Whenever a notice or other communication to the Preferred
Security Holder is required under this Declaration, unless and until Definitive
Preferred Security Certificates shall have been issued to the Preferred
Security Beneficial Owners pursuant to Section 9.7 the Regular Trustees shall
give all such notices and communications specified herein to be given to the
Preferred Security Holders to the Depositary, and shall have no notice
obligations to the Preferred Security Beneficial Owners.

Section 9.6  Appointment of Successor Depositary.

                 If any Depositary elects to discontinue its services as
securities depositary with respect to the Preferred Securities, the Regular
Trustees may, in their sole discretion, appoint a successor Depositary with
respect to such Preferred Securities.

Section 9.7  Definitive Preferred Security Certificates.

                 If:

         (a)     a Depositary elects to discontinue its services as securities
                 depositary with respect to the Preferred Securities and a
                 successor Depositary is not appointed within 90 days after
                 such discontinuance pursuant to Section 9.6; or

         (b)     the Regular Trustees elect after consultation with the Sponsor
                 to terminate the book entry system through the Depositary with
                 respect to the Preferred Securities,





                                       39
<PAGE>   45

then:

         (c)     Definitive Preferred Security Certificates shall be prepared
                 by the Regular Trustees on behalf of the Trust with respect to
                 such Preferred Securities; and

         (d)     upon surrender of the Global Certificates by the Depositary,
                 accompanied by registration instructions, the Regular Trustees
                 shall cause Definitive Certificates to be delivered to
                 Preferred Security Beneficial Owners in accordance with the
                 instructions of the Depositary.  Neither the Trustees nor the
                 Trust shall be liable for any delay in delivery of such
                 instructions and each of them may conclusively rely on and
                 shall be protected in relying on, said instructions of the
                 Depositary.  The Definitive Preferred Security Certificates
                 shall be printed, lithographed or engraved or may be produced
                 in any other manner as is reasonably acceptable to the Regular
                 Trustees, as evidenced by their execution thereof, and may
                 have such letters, numbers or other marks of identification or
                 designation and such legends or endorsements as the Regular
                 Trustees may deem appropriate, or as may be required to comply
                 with any law or with any rule or regulation made pursuant
                 thereto or with any rule or regulation of any stock exchange
                 on which Preferred Securities may be listed, or to conform to
                 usage.

Section 9.8  Mutilated, Destroyed, Lost or Stolen Certificates.

                 If:

         (a)     any mutilated Certificates should be surrendered to the
                 Regular Trustees, or if the Regular Trustees shall receive
                 evidence to their satisfaction of the destruction, loss or
                 theft of any Certificate; and

         (b)     there shall be delivered to the Regular Trustees such security
                 or indemnity as may be required by them to keep each of them
                 harmless.

then:

                 In the absence of notice that such Certificate shall have been
acquired by a bona fide purchaser, any two Regular Trustees on behalf of the
Trust shall execute and deliver, in exchange for or in lieu of any such
mutilated, destroyed, lost or stolen Certificate, a new Certificate of like
denomination.  In connection with the issuance of any new Certificate under
this Section 9.8, the Regular Trustees may require the payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
connection therewith.  Any duplicate





                                       40
<PAGE>   46
Certificate issued pursuant to this Section shall constitute conclusive evidence
of an ownership interest in the relevant Trust Securities, as if originally
issued, whether or not the lost, stolen or destroyed Certificate shall be found
at any time.


                                   ARTICLE X
                       Limitation of Liability of Holders
                    of Trust Securities, Trustees or Others

Section 10.1  Liability.

         (a)     Except as expressly set forth in this Declaration, the
                 Preferred Securities Guarantee, the Common Securities
                 Guarantee and the terms of the Trust Securities, the Sponsor
                 shall not be:

                 (i)      personally liable for the return of any portion of
                          the capital contributions (or any return thereon) of
                          the Holders of the Trust Securities which shall be
                          made solely from assets of the Trust; and

                 (ii)     be required to pay to the Trust or to any Holder of
                          Trust Securities any deficit upon dissolution of the
                          Trust or otherwise.

         (b)     Pursuant to Section 3803(a) of the Business Trust Act:

                 (i)      the Holder of the Common Securities shall be liable
                          for all of the debts and obligations of the Trust
                          (other than with respect to the Trust Securities) to
                          the extent not satisfied out of the Trust's assets;
                          and

                 (ii)     the Holders of the Preferred Securities shall be
                          entitled to the same limitation of personal liability
                          extended to stockholders of private corporations for
                          profit organized under the General Corporation Law of
                          the State of Delaware.

Section 10.2  Exculpation.

         (a)     No Indemnified Person shall be liable, responsible or
                 accountable in damages or otherwise to the Trust or any
                 Covered Person for any loss, damage or claim incurred by
                 reason of any act or omission performed or omitted by such
                 Indemnified Person in good faith on behalf of the Trust and in
                 a manner such Indemnified Person reasonably believed to be
                 within the scope of the authority conferred on such
                 Indemnified Person by this Declaration or by law, except that
                 an Indemnified Person shall be liable for any such loss,
                 damage or





                                       41
<PAGE>   47
                 claim incurred by reason of such Indemnified Person's gross
                 negligence (or, in the case of the Property Trustee,
                 negligence) or willful misconduct with respect to such acts or
                 omissions.

         (b)     An Indemnified Person shall be fully protected in relying in
                 good faith upon the records of the Trust and upon such
                 information, opinions, reports or statements presented to the
                 Trust by any Person as to matters the Indemnified Person
                 reasonably believes are within such other Person's
                 professional or expert competence and who has been selected
                 with reasonable care by or on behalf of the Trust, including
                 information, opinions, reports or statements as to the value
                 and amount of the assets, liabilities, profits, losses, or any
                 other facts pertinent to the existence and amount of assets
                 from which Distributions to Holders of Trust Securities might
                 properly be paid.

Section 10.3  Fiduciary Duty.

         (a)     To the extent that, at law or in equity, an Indemnified Person
                 has duties (including fiduciary duties) and liabilities
                 relating thereto to the Trust or to any other Covered Person,
                 an Indemnified Person acting under this Declaration shall not
                 be liable to the Trust or to any other Covered Person for its
                 good faith reliance on the provisions of this Declaration.
                 The provisions of this Declaration, to the extent that they
                 restrict the duties and liabilities of an Indemnified Person
                 otherwise existing at law or in equity (other than the duties
                 imposed on the Property Trustee under the Trust Indenture
                 Act), are agreed by the parties hereto to replace such other
                 duties and liabilities of such Indemnified Person.

         (b)     Unless otherwise expressly provided herein:

                 (i)      whenever a conflict of interest exists or arises
                          between an Indemnified Person and any Covered Person;
                          or

                 (ii)     whenever this Declaration or any other agreement
                          contemplated herein or therein provides that an
                          Indemnified Person shall act in a manner that is, or
                          provides terms that are, fair and reasonable to the
                          Trust or any Holder of Trust Securities,

                 the Indemnified Person shall resolve such conflict of
                 interest, take such action or provide such terms, considering
                 in each case the relative interest of each party (including
                 its own interest) to such conflict,





                                       42
<PAGE>   48
                 agreement, transaction or situation and the benefits and
                 burdens relating to such interests, any customary or accepted
                 industry practices, and any applicable generally accepted
                 accounting practices or principles.  In the absence of bad
                 faith by the Indemnified Person, the resolution, action or term
                 so made, taken or provided by this Indemnified Person shall not
                 constitute a breach of this Declaration or any other agreement
                 contemplated herein or of any duty or obligation of the
                 Indemnified Person at law or in equity or otherwise.

         (c)     Whenever in this Declaration an Indemnified Person is
                 permitted or required to make a decision

                 (i)      in its "discretion" or under a grant of similar
                          authority, the Indemnified Person shall be entitled
                          to consider such interests and factors as it desires,
                          including its own interests, and shall have no duty
                          or obligation to give any consideration to any
                          interest of or factors affecting the Trust or any
                          other Person; or

                 (ii)     in its "good faith" or under another express
                          standard, the Indemnified Person shall act under such
                          express standard and shall not be subject to any
                          other or different standard imposed by this
                          Declaration or by applicable law.

Section 10.4  Indemnification.

         (a)     To the fullest extent permitted by applicable law, the Sponsor
                 shall indemnify and hold harmless each Indemnified Person from
                 and against any loss, damage, liability, tax, penalty, expense
                 or claim of any kind or nature whatsoever incurred by such
                 Indemnified Person by reason of the creation, operation or
                 termination of the Trust or any act or omission performed or
                 omitted by such Indemnified Person in good faith on behalf of
                 the Trust and in a manner such Indemnified Person reasonably
                 believed to be within the scope of authority conferred on such
                 Indemnified Person by this Declaration, except that no
                 Indemnified Person shall be entitled to be indemnified in
                 respect of any loss, damage or claim incurred by such
                 Indemnified Person by reason of gross negligence (or, in the
                 case of the Property Trustee, negligence) or willful
                 misconduct with respect to such acts or omissions.

         (b)     To the fullest extent permitted by applicable law, expenses
                 (including legal fees) incurred by an Indemnified Person in
                 defending any claim, demand, action, suit or proceeding shall,
                 from time to time, be





                                       43
<PAGE>   49
                 advanced by the Sponsor prior to the final disposition of such
                 claim, demand, action, suit or proceeding upon receipt by the
                 Sponsor of an undertaking by or on behalf of the Indemnified
                 Person to repay such amount if it shall be determined that the
                 Indemnified Person is not entitled to be indemnified as
                 authorized in Section 10.4(a).  The indemnification shall
                 survive the termination of this Declaration or the earlier
                 removal or resignation of any of the Trustees or the Property
                 Trustee.

Section 10.5  Outside Businesses.

                 Any Covered Person, the Sponsor, the Note Issuer, the Delaware
Trustee and the Property Trustee may engage in or possess an interest in other
business ventures of any nature or description, independently or with others,
similar or dissimilar to the business of the Trust, and the Trust and the
Holders of Trust Securities shall have no rights by virtue of this Declaration
in and to such independent ventures or the income or profits derived therefrom
and the pursuit of any such venture, even if competitive with the business of
the Trust, shall not be deemed wrongful or improper.  No Covered Person, the
Sponsor, the Note Issuer, the Delaware Trustee, or the Property Trustee shall
be obligated to present any particular investment or other opportunity to the
Trust even if such opportunity is of a character that, if presented to the
Trust, could be taken by the Trust, and any Covered Person, the Sponsor, the
Note Issuer, the Delaware Trustee and the Property Trustee shall have the right
to take for its own account (individually or as a partner or fiduciary) or to
recommend to others any such particular investment or other opportunity.  Any
Covered Person, the Delaware Trustee and the Property Trustee may engage or be
interested in any financial or other transaction with the Sponsor or any
Affiliate of the Sponsor, or may act as depositary for, trustee or agent for,
or act on any committee or body of holders of, securities or other obligations
of the Sponsor or its Affiliates.


                                   ARTICLE XI
                                   Accounting

Section 11.1  Fiscal Year.

                 The fiscal year ("Fiscal Year") of the Trust shall be the
calendar year, or such other year as is required by the Code.

Section 11.2  Certain Accounting Matters.

         (a)     At all times during the existence of the Trust, the Regular
                 Trustees shall keep, or cause to be kept, full





                                       44
<PAGE>   50
                 books of account, records and supporting documents, which shall
                 reflect in reasonable detail, each transaction of the Trust.
                 The books of account shall be maintained on the accrual method
                 of accounting, in accordance with generally accepted accounting
                 principles, consistently applied.  The Trust shall use the
                 accrual method of accounting for United States federal income
                 tax purposes. The books of account and the records of the Trust
                 shall be examined by and reported upon as of the end of each
                 Fiscal Year by a firm of independent certified public
                 accountants selected by the Regular Trustees.

         (b)     The Regular Trustees shall cause to be prepared and delivered
                 to each of the Holders of Trust Securities, within 90 days
                 after the end of each Fiscal Year of the Trust, annual
                 financial statements of the Trust, including a balance sheet
                 of the Trust as of the end of such Fiscal Year, and the
                 related statements of income or loss.

         (c)     The Regular Trustees shall cause to be duly prepared and
                 delivered to each of the Holders of Trust Securities any
                 United States federal income tax information statement
                 required by the Code, containing such information with regard
                 to the Trust Securities held by each Holder as is required by
                 the Code and the Treasury Regulations, and any comparable
                 statements required to be provided under the law of any other
                 taxing jurisdiction.  Notwithstanding any right under the Code
                 or other law to deliver any such statement at a later date,
                 the Regular Trustees shall endeavor to deliver all such
                 statements within 30 days after the end of each Fiscal Year of
                 the Trust.

         (d)     The Regular Trustees shall cause to be duly prepared and filed
                 with the appropriate taxing authority an annual United States
                 federal income tax return Form 1041 or such other form
                 required by United States federal income tax law, and any
                 other tax returns or reports required to be filed by the
                 Regular Trustees on behalf of the Trust with any state or
                 local taxing authority.

Section 11.3  Banking.

                 The Trust shall maintain one or more bank accounts in the name
and for the sole benefit of the Trust; provided, however, that all payments of
funds in respect of the Notes held by the Property Trustee shall be made
directly to the Property Trustee Account and no other funds of the Trust shall
be deposited in the Property Trustee Account.  The sole signatories





                                       45
<PAGE>   51
for such accounts shall be designated by the Regular Trustees; provided,
however, that the Property Trustee shall designate the sole signatories for the
Property Trustee Account.

Section 11.4  Withholding.

                 The Trust and the Regular Trustees shall comply with all
withholding requirements under United States federal, state and local law.  The
Trust shall request, and the Holders shall provide to the Trust, such forms or
certificates as are necessary to establish an exemption from withholding with
respect to each Holder, and any representations and forms as shall reasonably
be requested by the Trust to assist it in determining the extent of, and in
fulfilling, its withholding obligations.  The Regular Trustees shall file
required forms with applicable jurisdictions and, unless an exemption from
withholding is properly established by a Holder, shall remit amounts withheld
with respect to the Holder to applicable jurisdictions.  To the extent that the
Trust is required to withhold and pay over any amounts to any authority with
respect to distributions or allocations to any Holder, the amount withheld
shall be deemed to be a distribution in the amount of the withholding to the
Holder.  In the event of any claimed over withholding, Holders shall be limited
to an action against the applicable jurisdiction.  If the amount required to be
withheld was not withheld from actual Distributions made to any Holder, the
Trust may reduce subsequent Distributions to such Holder by the amount of such
withholding.


                                  ARTICLE XII
                            Amendments and Meetings

Section 12.1  Amendments.

         (a)     Except as otherwise provided in this Declaration or by any
                 applicable terms of the Trust Securities, this Declaration may
                 only be amended by a written instrument approved and executed
                 by:

                 (i)      the Regular Trustees (or, if there are more than two
                          Regular Trustees a majority of the Regular Trustees);

                 (ii)     if the amendment affects the rights, powers, duties,
                          obligations or immunities of the Property Trustee,
                          the Property Trustee; and

                 (iii)    if the amendment affects the rights, powers, duties,
                          obligations or immunities of the Delaware Trustee,
                          the Delaware Trustee;





                                       46
<PAGE>   52
         (b)     No amendment shall be made, and any purported amendment shall
                 be void and ineffective:

                 (i)      unless, in the case of any proposed amendment, the
                          Property Trustee shall have first received an
                          Officers' Certificate from each of the Trust and the
                          Sponsor that such amendment is permitted by, and
                          conforms to, the terms of this Declaration (including
                          the terms of the Trust Securities);

                 (ii)     unless, in the case of any proposed amendment which
                          affects the rights, powers, duties, obligations or
                          immunities of the Property Trustee, the Property
                          Trustee shall have first received:

                          (A)     an Officers' Certificate from each of the
                                  Trust and the Sponsor that such amendment is
                                  permitted by, and conforms to, the terms of
                                  this Declaration (including the terms of the
                                  Trust Securities); and

                          (B)     an opinion of counsel (who may be counsel to
                                  the Sponsor or the Trust) that such amendment
                                  is permitted by, and conforms to, the terms
                                  of this Declaration (including the terms of
                                  the Trust Securities); and

                 (iii)    to the extent the result of such amendment would be
                          to:

                          (A)     cause the Trust to fail to continue to be
                                  classified for purposes of United States
                                  federal income taxation as a grantor trust;

                          (B)     reduce or otherwise adversely affect the
                                  powers of the Property Trustee in
                                  contravention of the Trust Indenture Act; or

                          (C)     cause the Trust to be deemed to be an
                                  Investment Company required to be registered
                                  under the Investment Company Act.

         (c)     at such time after the Trust has issued any Trust Securities
                 that remain outstanding, any amendment that would adversely
                 affect the rights, privileges or preferences of any Holder of
                 Trust Securities may be effected only with such additional
                 requirements as may be set forth in the terms of such Trust
                 Securities;

         (d)     Section 9.1(c) and this Section 12.1 shall not be amended
                 without the consent of all of the Holders of the Trust
                 Securities;





                                       47
<PAGE>   53

         (e)     Article IV shall not be amended without the consent of the
                 Holders of a Majority in liquidation amount of the Common
                 Securities;

         (f)     the rights of the holders of the Common Securities under
                 Article V to increase or decrease the number of, and appoint
                 and remove Trustees shall not be amended without the consent
                 of the Holders of a Majority in liquidation amount of the
                 Common Securities; and

         (g)     notwithstanding Section 12.1(c), this Declaration may be
                 amended without the consent of the Holders of the Trust
                 Securities to:

                 (i)      cure any ambiguity;

                 (ii)     correct or supplement any provision in this
                          Declaration that may be defective or inconsistent
                          with any other provision of this Declaration;

                 (iii)    add to the covenants, restrictions or obligations of
                          the Sponsor; and

                 (iv)     conform to any change in Rule 3a-5 or other exemption
                          from the requirement to register as an Investment
                          Company under the Investment Company Act or written
                          change in the interpretation or application thereof
                          by any legislative body, court, government agency or
                          regulatory authority which amendment does not have a
                          material adverse effect on the rights, preferences or
                          privileges of the Holders.

Section 12.2  Meetings of the Holders of Trust Securities; Action by Written
              Consent.

         (a)     Meetings of the Holders of any class of Trust Securities may
                 be called at any time by the Regular Trustees (or as provided
                 in the terms of the Trust  Securities) to consider and act on
                 any matter on which Holders of such class of Trust Securities
                 are entitled to act under the terms of this Declaration, the
                 terms of the Trust Securities or the rules of any stock
                 exchange, the NASDAQ National Market System or other
                 organization on which the Preferred Securities are listed or
                 admitted for trading.  The Regular Trustees shall call a
                 meeting of the Holders of such class if directed to do so by
                 the Holders of at least 10% in liquidation amount of such
                 class of Trust Securities.  Such direction shall be given by
                 delivering to the Regular Trustees one or more calls in a
                 writing stating that the signing Holders of Trust Securities
                 wish to





                                       48
<PAGE>   54
                 call a meeting and indicating the general or specific purpose
                 for which the meeting is to be called.  Any Holders of Trust
                 Securities calling a meeting shall specify in writing the
                 Certificates held by the Holders of Trust Securities exercising
                 the right to call a meeting and only those Trust Securities
                 specified shall be counted for purposes of determining whether
                 the required percentage set forth in the second sentence of
                 this paragraph has been met.

         (b)     Except to the extent otherwise provided in the terms of the
                 Trust Securities, the following provisions shall apply to
                 meetings of Holders of Trust Securities:

                 (i)      notice of any such meeting shall be given to all the
                          Holders of Trust Securities having a right to vote
                          thereat at least 7 days and not more than 60 days
                          before the date of such meeting.  Whenever a vote,
                          consent or approval of the Holders of Trust
                          Securities is permitted or required under this
                          Declaration or the rules of any stock exchange, the
                          NASDAQ National Market System or other organization
                          on which the Preferred Securities are listed or
                          admitted for trading, such vote, consent or approval
                          may be given at a meeting of the Holders of Trust
                          Securities.  Any action that may be taken at a
                          meeting of the Holders of Trust Securities may be
                          taken without a meeting if a consent in writing
                          setting forth the action so taken is signed by the
                          Holders of Trust Securities owning not less than the
                          minimum amount of Trust Securities in liquidation
                          amount that would be necessary to authorize or take
                          such action at a meeting at which all Holders of
                          Trust Securities having a right to vote thereon were
                          present and voting.  Prompt notice of the taking of
                          action without a meeting shall be given to the
                          Holders of Trust Securities entitled to vote who have
                          not consented in writing.  The Regular Trustees may
                          specify that any written ballot submitted to a Holder
                          for the purpose of taking any action without a
                          meeting shall be returned to the Trust within the
                          time specified by the Regular Trustees;

                 (ii)     each Holder of a Trust Security may authorize any
                          Person to act for it by proxy on all matters in which
                          a Holder of Trust Securities is entitled to
                          participate, including waiving notice of any meeting,
                          or voting or participating at a meeting.  No proxy
                          shall be valid after the expiration of 11 months from
                          the date thereof unless otherwise provided in the
                          proxy.  Every proxy shall be





                                       49
<PAGE>   55
                          revocable at the pleasure of the Holder of Trust
                          Securities executing it.  Except as otherwise provided
                          herein, all matters relating to the giving, voting or
                          validity of proxies shall be governed by the General
                          Corporation Law of the State of Delaware relating to
                          proxies, and judicial interpretations thereunder, as
                          if the Trust were a Delaware corporation and the
                          Holders of the Trust Securities were stockholders of a
                          Delaware corporation;

                 (iii)    each meeting of the Holders of the Trust Securities
                          shall be conducted by the Regular Trustees or by such
                          other Person that the Regular Trustees may designate;
                          and

                 (iv)     unless the Business Trust Act, this Declaration, the
                          terms of the Trust Securities, the Trust Indenture
                          Act or the listing rules of any stock exchange, the
                          NASDAQ National Market System or other organization
                          on which the Preferred Securities are then listed or
                          trading, otherwise provides, the Regular Trustees, in
                          their sole discretion, shall establish all other
                          provisions relating to meetings of Holders of Trust
                          Securities, including notice of the time, place or
                          purpose of any meeting at which any matter is to be
                          voted on by any Holders of Trust Securities, waiver
                          of any such notice, action by consent without a
                          meeting, the establishment of a record date, quorum
                          requirements, voting in person or by proxy or any
                          other matter with respect to the exercise of any such
                          right to vote.


                                  ARTICLE XIII
                       Representations and Warranties of
                     Property Trustee and Delaware Trustee

Section 13.1  Representations and Warranties of Property Trustee.

                 The trustee that acts as initial Property Trustee represents
and warrants to the Trust and to the Sponsor at the date of this Declaration,
and each successor Property Trustee represents and warrants to the Trust and
the Sponsor at the time of the successor Property Trustee's acceptance of its
appointment as Property Trustee that:

         (a)     The Property Trustee is a banking corporation with trust
                 powers, duly organized, validly existing and in good standing
                 under the laws of the United States or the State of Illinois,
                 with trust power and authority





                                       50
<PAGE>   56
                 to execute and deliver, and to carry out and perform its
                 obligations under the terms of, the Declaration and with its
                 principal place of business in Illinois.

         (b)     The execution, delivery and performance by the Property
                 Trustee of the Declaration has been duly authorized by all
                 necessary corporate action on the part of the Property
                 Trustee.  The Declaration has been duly executed and delivered
                 by the Property Trustee, and it constitutes a legal, valid and
                 binding obligation of the Property Trustee, enforceable
                 against it in accordance with its terms, subject to applicable
                 bankruptcy, reorganization, moratorium, insolvency, and other
                 similar laws affecting creditors' rights generally and to
                 general principles of equity and the discretion of the court
                 (regardless of whether the enforcement of such remedies is
                 considered in a proceeding in equity or at law).

         (c)     The execution, delivery and performance of the Declaration by
                 the Property Trustee does not conflict with or constitute a
                 breach of the charter or By-laws of the Property Trustee.

         (d)     The Property Trustee, pursuant to the Declaration, shall hold
                 legal title and a valid ownership interest in the Notes in
                 accordance with the provisions hereof.

Section 13.2  Representations and Warranties of Delaware Trustee.

                 The trustee that acts as initial Delaware Trustee represents
and warrants to the Trust and to the Sponsor at the date of this Declaration,
and each successor Delaware Trustee represents and warrants to the Trust and to
the Sponsor at the time of its acceptance of its appointment as Delaware
Trustee that:

         (a)     The Delaware Trustee is either a natural person who is a
                 resident of the State of Delaware or, if not a natural person,
                 an entity which has its principal place of business in the
                 State of Delaware.

         (b)     The execution, delivery and performance by the Delaware
                 Trustee of the Declaration and Certificate of Trust has been
                 duly authorized by all necessary corporate action on the part
                 of the Delaware Trustee.  The Declaration has been duly
                 executed and delivered by the Delaware Trustee and, under
                 Delaware law, constitutes a legal, valid and binding
                 obligation of the Delaware Trustee, enforceable against it in
                 accordance with its terms, subject to applicable bankruptcy,
                 reorganization, moratorium, insolvency, and other similar laws





                                       51
<PAGE>   57
                 affecting creditors' rights generally and to general principles
                 of equity and the discretion of the court (regardless of
                 whether the enforcement of such remedies is considered in a
                 proceeding in equity or at law).

         (c)     The execution, delivery and performance of the Declaration and
                 Certificate of Trust by the Delaware Trustee does not conflict
                 with or constitute a breach of the charter or By-laws of the
                 Delaware Trustee.

                                  ARTICLE XIV
                                 Miscellaneous

Section 14.1     Notices.

                 All notices, instructions, requests and demands provided for
in this Declaration shall be in writing, duly signed by the party giving same,
and shall be delivered, telecopied or mailed by registered or certified mail,
as follows:

         (a)     if given to the Trust, in care of the Regular Trustees at the
                 Trust's mailing address set forth below (or such other address
                 as the Trust may give notice of to the Holders of the Trust
                 Securities):

                          SOUTHWEST GAS CAPITAL I
                          5241 Spring Mountain Road
                          Las Vegas, Nevada  89102
                          Telecopy number:  (702) 876-7037

         (b)     if given to the Property Trustee, at the mailing address set
                 forth below (or such other address as the Property Trustee may
                 give notice of to the Holders of the Trust Securities):

                          HARRIS TRUST AND SAVINGS BANK
                          311 West Monroe Street, 12th Floor
                          Chicago, Illinois 60606
                          Attention:  Indenture Trust Division
                          Telecopy number:  (312) 461-3525





                                       52
<PAGE>   58
         (c)     if given to the Delaware Trustee, at the mailing address set
                 forth below (or such other address as the Delaware Trustee may
                 give notice of to the Holders of the Trust Securities):

                          WILMINGTON TRUST COMPANY
                          1100 North Market Street
                          Wilmington, Delaware 19890

         (d)     if given to the Holder of the Common Securities, at the
                 mailing address of the Sponsor set forth below (or such other
                 address as the Holder of the Common Securities may give notice
                 to the Trust):

                          SOUTHWEST GAS CORPORATION
                          5241 Spring Mountain Road
                          Las Vegas, Nevada  89102
                          Attention:  Chief Financial Officer
                          Telecopy number:  (702) 876-7037

         (e)     if given to any other Holder, at the address set forth on the
                 books and records of the Trust.

                 All such notices shall be deemed to have been given when
received in person, telecopied with receipt confirmed, or mailed by first class
mail, postage prepaid except that if a notice or other document is refused
delivery or cannot be delivered because of a changed address of which no notice
was given, such notice or other document shall be deemed to have been delivered
on the date of such refusal or inability to deliver.

Section 14.2  Governing Law.

                 This Declaration and the rights of the parties hereunder shall
be governed by and interpreted in accordance with the laws of the State of
Delaware and all rights and remedies shall be governed by such laws without
regard to principles of conflict of laws.

Section 14.3  Intention of the Parties.

                 It is the intention of the parties hereto that the Trust not
be characterized for United States federal income tax purposes as an
association taxable as a corporation or a partnership but rather that the Trust
be characterized as a grantor trust or otherwise in a manner such that each
Holder of Trust Securities will be treated as owning an undivided beneficial
interest in the Notes.  The provisions of this Declaration shall be interpreted
to further this intention of the parties.





                                       53
<PAGE>   59
Section 14.4  Headings.

                 Headings contained in this Declaration are inserted for
convenience of reference only and do not affect the interpretation of this
Declaration or any provision hereof.

Section 14.5  Successors and Assigns.

                 Whenever in this Declaration any of the parties hereto is
named or referred to, the successors and assigns of such party shall be deemed
to be included, and all covenants and agreements in this Declaration by the
Sponsor and the Trustees shall bind and inure to the benefit of their
respective successors and assigns, whether so expressed.

Section 14.6  Partial Enforceability.

                 If any provision of this Declaration, or the application of
such provision to any Person or circumstance, shall be held invalid, the
remainder of this Declaration, or the application of such provision to persons
or circumstances other than those to which it is held invalid, shall not be
affected thereby.

Section 14.7  Counterparts.

                 This Declaration may contain more than one counterpart of the
signature page and this Declaration may be executed by the affixing of the
signature of each of the Trustees and the Property Trustee to one of such
counterpart signature pages.  All of such counterpart signature pages shall be
read as though one, and they shall have the same force and effect as though all
of the signers had signed a single signature page.





                                       54
<PAGE>   60

                 IN WITNESS WHEREOF, the undersigned has caused these presents
to be executed as of the day and year first above written.

                 GEORGE C. BIEHL,
                 as Trustee

                 ------------------------------


                 JEFFREY W. SHAW,
                 as Trustee

                 ------------------------------


                 WILMINGTON TRUST COMPANY,
                 as Delaware Trustee


                 ------------------------------
                 By:
                      -------------------------
                 Name:
                        -----------------------
                 Title:
                        -----------------------


                 SOUTHWEST GAS CORPORATION,
                 as Sponsor

                 By:
                      -------------------------
                 Name:
                        -----------------------
                 Title:
                        -----------------------


                 HARRIS TRUST AND SAVINGS BANK,
                 as Property Trustee


                 By:
                      -------------------------
                 Name:
                        -----------------------
                 Title:
                        -----------------------





                                       55
<PAGE>   61
                                   EXHIBIT A


                                    TERMS OF
                   __% TRUST ORIGINATED PREFERRED SECURITIES
                     __% TRUST ORIGINATED COMMON SECURITIES


                 Pursuant to Section 7.1 of the Amended and Restated
Declaration of Trust, dated as of ___________________, ____ (as amended from
time to time, the "Declaration"), the designation, rights, privileges,
restrictions, preferences and other terms and provisions of the Preferred
Securities and the Common Securities are set out below (each capitalized term
used but not defined herein has the meaning set forth in the Declaration or, if
not defined in such Declaration, as defined in the Prospectus referred to
below):

1.       Designation and Number.

         (a)     "Preferred Securities."  ______________ Preferred Securities
                 of the Trust with an aggregate liquidation amount with respect
                 to the assets of the Trust of $[_______________ million
                 ($___________)] [(1), plus up to an additional ______________
                 Preferred Securities of the Trust with an aggregate
                 liquidation preference with respect to the assets of the Trust
                 of $__________ solely to cover over-allotments as provided for
                 in the Underwriting Agreement (the "Additional Preferred
                 Securities")] and a liquidation amount with respect to the
                 assets of the Trust of $25 per Preferred Security, are hereby
                 designated for the purposes of identification only as "____%
                 Trust Originated Preferred Securities" (the "Preferred
                 Securities").  The Certificates evidencing the Preferred
                 Securities shall be substantially in the form attached hereto
                 as Annex I, with such changes and additions thereto or
                 deletions therefrom as may be required by ordinary usage,
                 custom or practice or to conform to the rules of any stock
                 exchange on which the Preferred Securities are listed.

         (b)     "Common Securities."  ____________ Common Securities of the
                 Trust with an aggregate liquidation amount with respect to the
                 assets of the Trust of $[__________ million ($__________)]
                 [(1), plus up to an additional _________ Common Securities of
                 the Trust with an aggregate liquidation amount with respect to
                 the assets of the Trust of $_________ to meet the capital
                 requirements of the Trust in the event of an issuance of
                 Additional Preferred Securities] and a liquidation amount with
                 respect to the assets of the Trust of $25 per Common Security,
                 are hereby designated for the





                                      A-1
<PAGE>   62
                 purposes of identification only as "____% Trust Originated
                 Common Securities" (the "Common Securities").  The Certificates
                 evidencing the Common Securities shall be substantially in the
                 form attached hereto as Annex II, with such changes and
                 additions thereto or deletions therefrom as may be required by
                 ordinary usage, custom or practice.

2.       Distributions.

         (a)     Distributions payable on each Trust Security will be fixed at
                 a rate per annum of [*.*]% (the "Coupon Rate") of the stated
                 liquidation amount of $25 per Trust Security, such rate being
                 the rate of interest payable on the Notes to be held by the
                 Property Trustee.  Distributions in arrears for more than one
                 quarter will bear interest thereon compounded quarterly at the
                 Coupon Rate (to the extent permitted by applicable law).  The
                 term "Distributions" as used herein includes such cash
                 distributions and any such interest payable unless otherwise
                 stated.  A Distribution is payable only to the extent that
                 payments are made in respect of the Notes held by the Property
                 Trustee.  The amount of Distributions payable for any period
                 will be computed for any full quarterly Distribution period on
                 the basis of a 360-day year of twelve 30-day months, and for
                 any period shorter than a full quarterly Distribution period
                 for which Distributions are computed,  Distributions will be
                 computed on the basis of the actual number of days elapsed per
                 30-day month.

         (b)     Distributions on the Trust Securities will be cumulative, will
                 accrue from __________________, ____, and will be payable
                 quarterly in arrears, on March 31, June 30, September 30, and
                 December 31 of each year, commencing on _____________, ____,
                 except as otherwise described below.  The Note Issuer has the
                 right under the Indenture to defer payments of interest by
                 extending the interest payment period from time to time on the
                 Notes for a period not exceeding 20 consecutive quarters (each
                 an "Extension Period") and, during such Extension Period,
                 Distributions will also be deferred.  Despite such deferral,
                 quarterly Distributions will continue to accrue with interest
                 thereon (to the extent permitted by applicable law) at the
                 Coupon Rate compounded quarterly during any such Extension
                 Period.  Prior to the termination of any such Extension
                 Period, the Note Issuer may further extend such Extension
                 Period; provided that such Extension Period together with all
                 such previous and further extensions thereof may not exceed 20
                 consecutive quarters.  Payments of accrued Distributions will
                 be payable to Holders as they appear on the books and records
                 of the Trust on





                                      A-2
<PAGE>   63
                 the first record date after the end of the Extension Period.
                 Upon the termination of any Extension Period and the payment of
                 all amounts then due, the Note Issuer may commence a new
                 Extension Period, subject to the above requirements.

         (c)     Distributions on the Trust Securities will be payable to the
                 Holders thereof as they appear on the books and records of the
                 Trust on the relevant record dates.  While the Preferred
                 Securities remain in book-entry only form, the relevant record
                 dates shall be one Business Day prior to the relevant payment
                 dates which payment dates correspond to the interest payment
                 dates on the Notes.  Subject to any applicable laws and
                 regulations and the provisions of the Declaration, each such
                 payment in respect of the Preferred Securities will be made as
                 described under the heading "Description of the Preferred
                 Securities -- Book-Entry Only Issuance -- The Depository Trust
                 Company" in the Prospectus Supplement dated _________________,
                 ____ (the "Prospectus Supplement"), to the Prospectus dated
                 _____________, ____ (together, the "Prospectus"), of the Trust
                 included in the Registration Statement on Form S-3 of the
                 Sponsor and the Trust.  The relevant record dates for the
                 Common Securities shall be the same record date as for the
                 Preferred Securities.  If the Preferred Securities shall not
                 continue to remain in book-entry only form, the relevant
                 record dates for the Preferred Securities, shall conform to
                 the rules of any securities exchange on which the securities
                 are listed and, if none, shall be selected by the Regular
                 Trustees, which dates shall be at least one Business Day but
                 less than 60 Business Days before the relevant payment dates,
                 which payment dates correspond to the interest payment dates
                 on the Notes.  Distributions payable on any Trust Securities
                 that are not punctually paid on any Distribution payment date,
                 as a result of the Note Issuer having failed to make a payment
                 under the Notes, will cease to be payable to the Person in
                 whose name such Trust Securities are registered on the
                 relevant record date, and such Distribution will instead be
                 payable to the Person in whose name such Trust  Securities are
                 registered on the special record date or other specified date
                 determined in accordance with the Indenture.  If any date on
                 which Distributions are payable on the Trust Securities is not
                 a Business Day, then payment of the Distribution payable on
                 such date will be made on the next succeeding day that is a
                 Business Day (and without any interest or other payment in
                 respect of any such delay) except that, if such Business Day
                 is in the next succeeding calendar year, such payment shall be
                 made on the immediately preceding





                                      A-3
<PAGE>   64
                 Business Day, in each case with the same force and effect as if
                 made on such date.

(d)      In the event that there is any money or other property held by or for
         the Trust that is not accounted for hereunder, such property shall be
         distributed Pro Rata (as defined herein) among the Holders of the
         Trust Securities.

3.       Liquidation Distribution Upon Dissolution.

                 In the event of any voluntary or involuntary dissolution,
winding-up or termination of the Trust, the Holders of the Trust Securities on
the date of the dissolution, winding-up or termination, as the case may be,
will be entitled to receive out of the assets of the Trust available for
distribution to Holders of Trust Securities after satisfaction of liabilities
to creditors of the Trust an amount equal to the aggregate of the stated
liquidation amount of $25 per Trust Security plus accrued and unpaid
Distributions thereon to the date of payment (such amount being the
"Liquidation Distribution"), unless, in connection with such dissolution,
winding-up or termination, Notes in an aggregate principal amount equal to the
aggregate stated liquidation amount of such Trust Securities shall be
distributed on a Pro Rata basis to the Holders of the Trust Securities in
exchange for such Trust Securities.

                 If, upon any such dissolution, the Liquidation Distribution
can be paid only in part because the Trust has insufficient assets available to
pay in full the aggregate Liquidation Distribution, then the amounts payable
directly by the Trust on the Trust Securities shall be paid on a Pro Rata
basis.

4.  Redemption and Distribution.

         (a)     Upon the repayment of the Notes in whole or in part, whether
                 at maturity or upon redemption, the proceeds from such
                 repayment or payment shall be simultaneously applied to redeem
                 Trust Securities having an aggregate liquidation amount equal
                 to the aggregate principal amount of the Notes so repaid or
                 redeemed at a redemption price of $25 per Trust Security plus
                 an amount equal to accrued and unpaid Distributions thereon at
                 the date of the redemption, payable in cash (the "Redemption
                 Price").  Holders will be given not less than 30 nor more than
                 60 days notice of such redemption.

         (b)     If fewer than all the outstanding Trust Securities are to be
                 so redeemed, the Common Securities and the Preferred
                 Securities will be redeemed Pro Rata and the Preferred
                 Securities to be redeemed will be as described in Paragraph
                 4(f)(ii) below.





                                      A-4
<PAGE>   65

         (c)     If a Tax Event (as defined below) shall occur and be
                 continuing the Regular Trustees shall dissolve the Trust and,
                 after satisfaction of liabilities to creditors of the Trust,
                 cause Notes held by the Property Trustee, having an aggregate
                 principal amount equal to the aggregate stated liquidation
                 amount of the Trust Securities, to be distributed to the
                 Holders of the Trust Securities in liquidation of such
                 Holders' interests in the Trust on a Pro Rata basis, within 90
                 days following the occurrence of such Tax Event (the "90-Day
                 Period"); provided, however, that as a condition of such
                 dissolution and distribution, the Regular Trustee shall have
                 received an opinion of a nationally recognized independent tax
                 counsel experienced in such matters (a "No Recognition
                 Opinion"), which opinion may rely on published revenue rulings
                 of the Internal Revenue Service, to the effect that the
                 Holders of the Trust Securities will not recognize any gain or
                 loss for United States federal income tax purposes as a result
                 of the dissolution of the Trust and the distribution of Notes,
                 and provided, further, that, if at the time there is available
                 to the Trust the opportunity to avoid, within the 90-day
                 Period, the Tax Event by taking some ministerial action, such
                 as filing a form or making an election, or pursuing some other
                 similar reasonable measure that has no adverse effect on the
                 Trust, the Note Issuer, the Sponsor or the Holders of the
                 Trust Securities ("Ministerial Action"), the Trust or the
                 Sponsor will pursue such Ministerial Action in lieu of
                 dissolution.

                 If (i) after receipt of a Dissolution Tax Opinion (as
                 hereafter defined) by and upon the request of the Regular
                 Trustees, the Note Issuer has received an opinion of a
                 nationally recognized independent tax counsel experienced in
                 such matters (a "Redemption Tax Opinion") to the effect that,
                 as a result of a Tax Event, there is more than an
                 insubstantial risk that the Note Issuer would be precluded
                 from deducting the interest on the Notes for United States
                 federal income tax purposes even if the Notes were distributed
                 to the Holders of Trust Securities in liquidation of such
                 Holders' interests in the Trust, as described in this
                 paragraph 4(c), or (ii) the Regular Trustees shall have been
                 informed by such tax counsel that a No Recognition Opinion
                 cannot be delivered to the Trust, the Note Issuer shall have
                 the right, upon not less than 30 nor more than 60 days notice,
                 to redeem the Notes in whole or in part for cash within 90
                 days following the occurrence of such Tax Event and, following
                 such redemption, Trust Securities with an aggregate
                 liquidation amount equal to the aggregate principal amount of
                 the Notes so redeemed shall be redeemed by





                                      A-5
<PAGE>   66
                 the Trust at the Redemption Price on a Pro Rata basis;
                 provided, however, that, if at the time there is available to
                 the Trust the opportunity to avoid within such 90-day Period,
                 the Tax Event by taking some Ministerial Action, the Trust or
                 the Sponsor will pursue such Ministerial Action in lieu of
                 redemption.

                 "Tax Event" means the receipt by, and upon the request of, the
                 Regular Trustees of an opinion of nationally recognized
                 independent tax counsel experienced in such matters to the
                 effect that, as a result of (a) any amendment to, or change
                 (including any announced prospective change) in, the laws (or
                 any regulations thereunder) of the United States or any
                 political subdivision or taxing authority thereof or therein,
                 (b) any amendment to or change in an interpretation or
                 application of such laws or regulations by any legislative
                 body, court, governmental agency or regulatory authority
                 (including the enactment of any legislation and the
                 publication of any judicial decision or regulatory
                 determination or after the date of the Prospectus Supplement
                 relating to the Preferred Securities of the Trust), (c) any
                 interpretation or pronouncement by any such body, court,
                 agency or authority that provides for a position with respect
                 to such laws or regulations that differs from the theretofore
                 generally accepted position, or (d) any action taken by any
                 governmental agency or regulatory authority, which amendment
                 or change is enacted, promulgated or effective, or which
                 interpretation or pronouncement is issued or announced, or
                 which action is taken, in each case on or after the date of
                 the Prospectus Supplement, there is more than an insubstantial
                 risk that (i) the Trust is, or within 90 days of the date
                 thereof will be, subject to United States federal income tax
                 with respect to income accrued or received on the Subordinated
                 Debt Securities, (ii) interest payable to the Trust on the
                 Subordinated Debt Securities is, or within 90 days of the date
                 thereof will, not be deductible, in whole or in part, by the
                 Note Issuer for United States federal income tax purposes or
                 (iii) the Trust is, or within 90 days of the date thereof will
                 be, subject to more than a deminimis amount of other taxes,
                 duties or other governmental charges.

                 On and from the date fixed by the Regular Trustees for any
                 distribution of Notes and dissolution of the Trust: (i) the
                 Trust Securities will no longer be deemed to be outstanding,
                 (ii) The Depository Trust Company (the "Depositary") or its
                 nominee (or any successor depositary or its nominee), as the
                 record Holder of the Preferred Securities, will receive a
                 registered global





                                      A-6
<PAGE>   67
                 certificate or certificates representing the Notes to be
                 delivered upon such distribution, and (iii) any certificates
                 representing Trust Securities not held by the Depositary or its
                 nominee (or any successor depositary or its nominee), will be
                 deemed to represent beneficial interests in the Notes having an
                 aggregate principal amount equal to the aggregate stated
                 liquidation amount of, with an interest rate identical to the
                 Coupon Rate of, and accrued and unpaid interest equal to
                 accrued and unpaid Distributions on such Trust Securities until
                 such certificates are presented to the Note Issuer or its agent
                 for transfer or reissue.

         (d)     The Trust may not redeem fewer than all the outstanding Trust
                 Securities unless all accrued and unpaid Distributions have
                 been paid on all Trust Securities for all quarterly
                 Distribution periods terminating on or before the date of
                 redemption.

         (e)     If the Notes are distributed to holders of the Trust
                 Securities, pursuant to the terms of the Indenture, the Note
                 Issuer will use its best efforts to have the Notes listed on
                 the New York Stock Exchange or on such other exchange, the
                 NASDAQ National Market System or other organization as the
                 Preferred Securities were listed immediately prior to the
                 distribution of the Notes.

         (f)     "Redemption or Distribution Procedures."

                 (i)      Notice of any redemption of, or notice of
                          distribution of Notes in exchange for the Trust
                          Securities (a "Redemption/Distribution Notice") will
                          be given by the Trust by mail to each Holder of Trust
                          Securities to be redeemed or exchanged not fewer than
                          30 nor more than 60 days before the date fixed for
                          redemption or exchange thereof which, in the case of
                          a redemption, will be the date fixed for redemption
                          of the Notes.  For purposes of the calculation of the
                          date of redemption or exchange and the dates on which
                          notices are given pursuant to this paragraph 4(f)(i),
                          a Redemption/Distribution Notice shall be deemed to
                          be given on the day such notice is first mailed by
                          first-class mail, postage prepaid, to Holders of
                          Trust Securities.  Each Redemption/Distribution
                          Notice shall be addressed to the Holders of Trust
                          Securities at the address of each such Holder
                          appearing in the books and records of the Trust.  No
                          defect in the Redemption/Distribution Notice or in
                          the mailing of either thereof with respect to any
                          Holder shall affect the validity of the redemption or
                          exchange proceedings with respect to any other
                          Holder.





                                      A-7
<PAGE>   68

                 (ii)     In the event that fewer than all the outstanding
                          Trust Securities are to be redeemed, the Trust
                          Securities to be redeemed shall be redeemed Pro Rata
                          and, in the event Preferred Securities are held in
                          book-entry only form by the Depositary or its nominee
                          (or any successor depositary or its nominee), the
                          Depositary will reduce Pro Rata the amount of the
                          interest of each Depositary Participant in the
                          Preferred Securities to be redeemed; provided, that
                          if, as a result of such Pro Rata redemption,
                          Depositary Participants would hold fractional
                          interests in the Preferred Securities, the Depositary
                          will adjust the amount of the interest of each
                          Depositary Participant to be redeemed to avoid such
                          fractional interests.

                 (iii)    If Trust Securities are to be redeemed and the Trust
                          gives a Redemption/Distribution Notice, which notice
                          may only be issued if the Notes are redeemed as set
                          out in this paragraph 4 (which notice will be
                          irrevocable), then (A) while the Preferred Securities
                          are in book-entry only form, with respect to the
                          Preferred Securities, by 12:00 noon, New York City
                          time, on the redemption date, provided that the Note
                          Issuer has paid the Property Trustee a sufficient
                          amount of cash in connection with the related
                          redemption or maturity of the Notes, the Property
                          Trustee will deposit irrevocably with the Depositary
                          (or successor depositary) funds sufficient to pay the
                          applicable Redemption Price with respect to the
                          Preferred Securities and will give the Depositary
                          irrevocable instructions and authority to pay the
                          Redemption Price to the Holders of the Preferred
                          Securities, and (B) with respect to Preferred
                          Securities issued in definitive form and Common
                          Securities, provided, that the Note Issuer has paid
                          the Property Trustee a sufficient amount of cash in
                          connection with the related redemption or maturity of
                          the Notes, the Property Trustee will pay the relevant
                          Redemption Price to the Holders of such Trust
                          Securities by check mailed to the address of the
                          relevant Holder appearing on the books and records of
                          the Trust on the redemption date.  If a
                          Redemption/Distribution Notice shall have been given
                          and funds deposited as required, if applicable, then
                          immediately prior to the close of business on the
                          date of such deposit, or on the redemption date, as
                          applicable, Distributions will cease to accrue on the
                          Trust Securities so called for redemption and all
                          rights of Holders of such Trust Securities so called
                          for redemption will cease, except the right of the
                          Holders of such





                                      A-8
<PAGE>   69
                          Trust Securities to receive the Redemption Price, but
                          without interest on such Redemption Price.  Neither
                          the Regular Trustees nor the Trust shall be required
                          to register or cause to be registered the transfer of
                          any Trust Securities that have been so called for
                          redemption.  If any date fixed for redemption of Trust
                          Securities is not a Business Day, then payment of the
                          Redemption Price payable on such date will be made on
                          the next succeeding day that is a Business Day (and
                          without any interest or other payment in respect of
                          any such delay) except that, if such Business Day
                          falls in the next calendar year, such payment will be
                          made on the immediately preceding Business Day, in
                          each case with the same force and effect as if made on
                          such date fixed for redemption.  If payment of the
                          Redemption Price in respect of any Trust Securities is
                          improperly withheld or refused and not paid either by
                          the Property Trustee or by the Sponsor as guarantor
                          pursuant to the Preferred Securities Guarantee or
                          Common Securities Guarantee, as the case may be,
                          Distributions on such Trust Securities will continue
                          to accrue from the original redemption date to the
                          actual date of payment, in which case the actual
                          payment date will be considered the date fixed for
                          redemption for purpose of calculating the Redemption
                          Price.

                 (iv)     Redemption/Distribution Notices shall be sent by the
                          Regular Trustees on behalf of the Trust to (A) in
                          respect of the Preferred Securities, the Depositary
                          or its nominee (or any successor depositary or its
                          nominee) if the Global Certificates have been issued
                          or, if Definitive Preferred Security Certificates
                          have been issued, to the Holder thereof, and (B) in
                          respect of the Common Securities to the Holder
                          thereof.

                 (v)      Subject to the foregoing and applicable law
                          (including, without limitation, United States federal
                          securities laws), provided the acquirer is not the
                          Holder of the Common Securities or the obligor under
                          the Indenture, the Sponsor or any of its subsidiaries
                          may at any time and from time to time purchase
                          outstanding Preferred Securities by tender, in the
                          open market or by private agreement.





                                      A-9
<PAGE>   70
5.       Voting Rights - Preferred Securities

         (a)     Except as provided under paragraphs 5(b) and 7 and as
                 otherwise required by law and the Declaration, the Holders of
                 the Preferred Securities will have no voting rights.

   
         (b)     Subject to the requirements set forth in this paragraph, the
                 Holders of a majority in liquidation amount of the Preferred
                 Securities, voting separately as a class may direct the time,
                 method, and place of conducting any proceeding for any remedy
                 available to the Property Trustee, or the exercise of any
                 trust or power conferred upon the Property Trustee under the
                 Declaration, including (i) directing the time, method, place
                 of conducting any proceeding for any remedy available to the
                 Note Trustee, or exercising any trust or power conferred on
                 the Note Trustee with respect to the Notes, (ii) waive any
                 past default and its consequences that is waivable under
                 Section 513 of the Indenture, or (iii) exercise any right to
                 rescind or annul a declaration that the principal of all the
                 Notes shall be due and payable, provided, however, that, where
                 a consent under the Indenture would require the consent or act
                 of all of the holders of Notes affected thereby, the Property
                 Trustee may only give such consent or take such action at the
                 direction of all of the Holders of the Preferred Securities.
                 The Property Trustee shall not revoke any action previously
                 authorized or approved by a vote of the Holders of the
                 Preferred Securities.  Other than with respect to directing
                 the time, method and place of conducting any remedy available
                 to the Property Trustee or the Note Trustee as set forth
                 above, the Property Trustee shall not take any action in
                 accordance with the directions of the Holders of the Preferred
                 Securities under this paragraph unless the Property Trustee
                 has obtained an opinion of tax counsel to the effect that for
                 the purposes of United States federal income tax the Trust
                 will not fail to be classified as a grantor trust on account
                 of such action.  If the Property Trustee fails to enforce its
                 rights under the Declaration, any Holder of Preferred
                 Securities may institute a legal proceeding directly
                 against any Person to enforce the Property Trustee's rights
                 under the Declaration without first instituting a legal
                 proceeding against the Property Trustee or any other Person.
    

                 Any approval or direction of Holders of Preferred Securities
                 may be given at a separate meeting of Holders of Preferred
                 Securities convened for such





                                      A-10
<PAGE>   71
                 purpose, at a meeting of all of the Holders of Trust Securities
                 in the Trust or pursuant to written consent.  The Regular
                 Trustees will cause a notice of any meeting at which Holders of
                 Preferred Securities are entitled to vote, or of any matter
                 upon which action by written consent of such Holders is to be
                 taken, to be mailed to each Holder of record of Preferred
                 Securities.  Each such notice will include a statement setting
                 forth (i) the date of such meeting or the date by which such
                 action is to be taken, (ii) a description of any resolution
                 proposed for adoption at such meeting on which such Holders are
                 entitled to vote or of such matter upon which the written
                 consent is sought and (iii) instructions for the delivery of
                 proxies or consents.

                 No vote or consent of the Holders of the Preferred Securities
                 will be required for the Trust to redeem and cancel Preferred
                 Securities or to distribute the Notes in accordance with the
                 Declaration and the terms of the Trust Securities.

                 Notwithstanding that Holders of Preferred Securities are
                 entitled to vote or consent under any of the circumstances
                 described above, any of the Preferred Securities that are
                 owned by the Sponsor or any Affiliate of the Sponsor shall not
                 be entitled to vote or consent and shall, for purposes of such
                 vote or consent, be treated as if they were not outstanding.

6.       Voting Rights - Common Securities.

         (a)     Except as provided under paragraphs 6(b), 6(c) and 7, and as
                 otherwise required by law and the Declaration, the Holders of
                 the Common Securities will have no voting rights.

         (b)     The Holders of the Common Securities are entitled, in
                 accordance with Article V of the Declaration, to vote to
                 appoint, remove or replace any Trustee or to increase or
                 decrease the number of Trustees.

         (c)     Subject to Section 2.6 of the Declaration and only after an
                 Event of Default with respect to the Preferred Securities has
                 been cured, waived or otherwise eliminated and subject to the
                 requirements of the second to last sentence of this paragraph,
                 the Holders of a Majority in liquidation amount of the Common
                 Securities, voting separately as a class, may direct the time,
                 method and place of conducting any proceeding for any remedy
                 available to the Property Trustee, or the exercise of any
                 trust or power conferred upon the Property Trustee under the
                 Declaration, including





                                      A-11
<PAGE>   72
                 (i) directing the time, method, place of conducting any
                 proceeding for any remedy available to the Property Trustee, or
                 exercising any trust or power conferred on the Property Trustee
                 with respect to the Notes, (ii) waive any past default and its
                 consequences that is waivable under Section 513 of the
                 Indenture, or (iii) exercise any right to rescind or annul a
                 declaration that the principal of all the Notes shall be due
                 and payable, provided, however, that, where a consent or action
                 under the Indenture would require the consent or act of all of
                 the holders of the Notes, the Property Trustee may only give
                 such consent or take such action at the direction of all of the
                 Holders of the Common Securities.  Pursuant to this paragraph
                 6(c), the Property Trustee shall not revoke any action
                 previously authorized or approved by a vote of the Holders of
                 the Common Securities.  Other than with respect to directing
                 the time, method and place of conducting any remedy available
                 to the Property Trustee or the Note Trustee as set forth above,
                 the Property Trustee shall not take any action in accordance
                 with the directions of the Holders of the Common Securities
                 under this paragraph unless the Property Trustee has obtained
                 an opinion of tax counsel to the effect that for the purposes
                 of United States federal income tax the Trust will not fail to
                 be classified as a grantor trust on account of such action.  If
                 the Property Trustee fails to enforce its rights under the
                 Declaration, any Holder of Common Securities may after written
                 request to the Property Trustee to enforce such rights,
                 institute a legal proceeding directly against any Person to
                 enforce the Property Trustee's rights under the Declaration,
                 without first instituting a legal proceeding against the
                 Property Trustee or any other person.

                 Any approval or direction of Holders of Common Securities may
                 be given at a separate meeting of Holders of Common Securities
                 convened for such purpose, at a meeting of all of the Holders
                 of Trust Securities in the Trust or pursuant to written
                 consent.  The Regular Trustees will cause a notice of any
                 meeting at which Holders of Common Securities are entitled to
                 vote, or of any matter upon which action by written consent of
                 such Holders is to be taken, to be mailed to each Holder of
                 record of Common Securities.  Each such notice will include a
                 statement setting forth (i) the date of such meeting or the
                 date by which such action is to be taken, (ii) a description
                 of any resolution proposed for adoption at such meeting on
                 which such Holders are entitled to vote or of such matter upon
                 which written consent is sought and (iii) instructions for the
                 delivery of proxies or consents.





                                      A-12
<PAGE>   73

                 No vote or consent of the Holders of the Common Securities
                 will be required for the Trust to redeem and cancel Common
                 Securities or to distribute the Notes in accordance with the
                 Declaration and the terms of the Trust Securities.

7.       Amendments to Declaration and Indenture.

         (a)     In addition to any requirements under Section 12.1 of the
                 Declaration, if any proposed amendment to the Declaration
                 provides for, or the Regular Trustees otherwise propose to
                 effect (i) any action that would adversely affect the powers,
                 preferences or special rights of the Trust Securities, whether
                 by way of amendment to the Declaration or otherwise, or (ii)
                 the dissolution, winding-up or termination of the Trust, other
                 than as described in Section 8.1 of the Declaration, then the
                 Holders of outstanding Trust Securities as a class, will be
                 entitled to vote on such amendment or proposal (but not on any
                 other amendment or proposal) and such amendment or proposal
                 shall not be effective except with the approval of the Holders
                 of at least 66-2/3% in liquidation amount of the Trust
                 Securities, voting together as a single class; provided,
                 however, if any amendment or proposal referred to in clause
                 (i) above would adversely affect only the Preferred Securities
                 or only the Common Securities, then only the affected class
                 will be entitled to vote on such amendment or proposal and
                 such amendment or proposal shall not be effective except with
                 the approval of 66-2/3% in liquidation amount of such class of
                 Trust Securities.

         (b)     In the event the consent of the Property Trustee as the holder
                 of the Notes, the Preferred Securities Guarantee and the
                 Common Securities Guarantee is required under the Indenture
                 with respect to any amendment, modification or termination of
                 the Indenture, the Notes, the Preferred Securities Guarantee
                 or the Common Securities Guarantee, the Property Trustee shall
                 request the direction of the Holders of the Trust Securities
                 with respect to such amendment, modification or termination
                 and shall vote with respect to such amendment, modification or
                 termination as directed by a Majority in liquidation amount of
                 the Trust Securities voting together as a single class;
                 provided, however, that where a consent under the Indenture
                 would require the consent of all of the holders of the Notes,
                 the Property Trustee may only give such consent at the
                 direction of all of the Holders of the Trust Securities;
                 provided, further, that the Property Trustee shall not take
                 any action in accordance with the directions of the Holders of
                 the Trust Securities





                                      A-13
<PAGE>   74
                 under this paragraph 7(b) unless the Property Trustee has
                 obtained an opinion of tax counsel to the effect that for the
                 purposes of United States federal income tax the Trust will not
                 be classified as other than a grantor trust on account of such
                 action.

8.       Pro Rata.

                 A reference to any payment, distribution or treatment as being
"Pro Rata" shall mean pro rata to each Holder of Trust Securities according to
the aggregate liquidation amount of the Trust Securities held by the relevant
Holder in relation to the aggregate liquidation amount of all Trust Securities
outstanding unless, in relation to a payment, an Event of Default under the
Indenture has occurred and is continuing, in which case any funds available to
make such payment shall be paid first to each Holder of the Preferred
Securities pro rata according to the aggregate liquidation amount of Preferred
Securities held by the relevant Holder relative to the aggregate liquidation
amount of all Preferred Securities outstanding, and only after satisfaction of
all amounts owed to the Holders of the Preferred Securities, to each Holder of
Common Securities pro rata according to the aggregate liquidation amount of
Common Securities held by the relevant Holder relative to the aggregate
liquidation amount of all Common Securities outstanding.

9.       Ranking.

                 The Preferred Securities rank pari passu and payment thereon
shall be made Pro Rata with the Common Securities except that, where an Event
of Default occurs and is continuing under the Indenture in respect of the Notes
held by the Property Trustee, the rights of Holders of the Common Securities to
payment in respect of Distributions and payments upon liquidation, redemption
and otherwise are subordinated to the rights to payment of the Holders of the
Preferred Securities.

10.      Listing.

                 The Regular Trustees shall use their best efforts to cause the
Preferred Securities to be listed for quotation on the New York Stock Exchange.

11.      Acceptance of Trust Securities Guarantee and Indenture.

                 Each Holder of Preferred Securities and Common Securities, by
the acceptance thereof, agrees to the provisions of the Preferred Securities
Guarantee and the Common Securities Guarantee, respectively, including the
subordination provisions therein and to the provisions of the Indenture.

12.      No Preemptive Rights.





                                      A-14
<PAGE>   75
                 The Holders of the Trust Securities shall have no preemptive
rights to subscribe for any additional securities.

13.      Miscellaneous.

                 These terms constitute a part of the Declaration.

                 The Sponsor will provide a copy of the Declaration, the
Preferred Securities Guarantee or the Common Securities Guarantee (as may be
appropriate), and the Indenture to a Holder without charge on written request
to the Trust at its principal place of business.





                                      A-15
<PAGE>   76
                                                                EXHIBIT 4.09
                                    ANNEX I

                 [IF THE PREFERRED SECURITY IS TO BE A GLOBAL CERTIFICATE
INSERT - This Preferred Security is a Global Certificate within the meaning of
the Declaration hereinafter referred to and is registered in the name of The
Depository Trust Company, a New York corporation (the "Depositary") or a
nominee of the Depositary.  This Preferred Security is exchangeable for
Preferred Securities registered in the name of a person other than the
Depositary or its nominee only in the limited circumstances described in the
Declaration and no transfer of this Preferred Security (other than a transfer
of this Preferred Security as a whole by the Depositary to a nominee of the
Depositary or by a nominee of the Depositary to the Depositary or another
nominee of the Depositary) may be registered except in limited circumstances.

                 Unless this Preferred Security is presented by an authorized
representative of the Depositary to the Trust or its agent for registration of
transfer, exchange or payment, and any Preferred Security issued is registered
in the name of Cede & Co.  or such other name as is requested by an authorized
representative of the Depositary and any payment hereon is made to Cede & Co.
or such other entity as is requested by an authorized representative of the
Depositary, ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY
A PERSON IS WRONGFUL since the registered owner hereof, Cede & Co., has an
interest herein.]

Certificate Number                                Number of Preferred Securities

                                                         CUSIP NO.
                                                                  --------------


                  Certificate Evidencing Preferred Securities

                                       of

                            SOUTHWEST GAS CAPITAL I


                              Preferred Securities
                (liquidation amount $25 per Preferred Security)


                 SOUTHWEST GAS CAPITAL I, a statutory business trust formed
under the laws of the State of Delaware (the "Trust"), hereby certifies that
___________________________ (the "Holder") is the registered owner of preferred
securities of the Trust representing undivided beneficial interests in the
assets of the Trust designated the _____% Trust Originated Preferred Securities
(liquidation amount $25 per Preferred Security) (the "Preferred Securities").
The Preferred Securities are transferable on the





                                      I-1
<PAGE>   77
books and records of the Trust, in person or by a duly authorized attorney,
upon surrender of this certificate duly endorsed and in proper form for
transfer.  The designation, rights, privileges, restrictions, preferences and
other terms and provisions of the Preferred Securities represented hereby are
issued and shall in all respects be subject to the provision of the Amended and
Restated Declaration of Trust of the Trust dated as of __________, ____, as the
same may be amended from time to time (the "Declaration"), including the
designation of the terms of the Preferred Securities as set forth in Exhibit A
to the Declaration.  Capitalized terms used herein but not defined shall have
the meaning given them in the Declaration.  The Holder is entitled to the
benefits of the Preferred Securities Guarantee to the extent provided therein.
The Sponsor will provide a copy of the Declaration, the Preferred Securities
Guarantee and the Indenture to a Holder without charge upon written request to
the Trust at its principal place of business.

         Upon receipt of this certificate, the Holder is bound by the
Declaration and is entitled to the benefits thereunder.

         By acceptance, the holder agrees to treat for United States federal
income tax purposes, the Notes as indebtedness and the Preferred Securities as
evidence of indirect beneficial ownership in the Notes.

         IN WITNESS WHEREOF, the Trust has executed this certificate this _____
day of _______________, 199___.

                                           George C. Biehl
                                           as Trustee



                                           -------------------------------
                                                                         



                                           Jeffrey W. Shaw
                                           as Trustee



                                           -------------------------------
                                                                         





                                      I-2
<PAGE>   78
                                   ASSIGNMENT


FOR VALUE RECEIVED, the undersigned assigns and transfers this Preferred
Security Certificate to:

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
(Insert assignee's social security or tax identification number)


- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
(Insert address and zip code of assignee) and irrevocably appoints)

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
agent to transfer this Preferred Security Certificate on the books of the Trust.
The agent may substitute another to act for him or her.

Date:
     -------------------------

Signature:
          -----------------------------------
(Sign exactly as your name appears on the other side of this Preferred Security
Certificate)





                                      I-3
<PAGE>   79
                                    ANNEX II


Certificate Number                                   Number of Common Securities


                    Certificate Evidencing Common Securities

                                       of

                            SOUTHWEST GAS CAPITAL I


                               Common Securities
                  (liquidation amount $25 per Common Security)


         SOUTHWEST GAS CAPITAL I, a statutory business trust formed under the
laws of the State of Delaware (the "Trust"), hereby certifies that
_______________ (the "Holder") is the registered owner of common securities of
the Trust representing undivided beneficial interests in the assets of the
Trust designated the %   ________ Trust Originated Common Securities
(liquidation amount $25 per Common Security) (the "Common Securities").  The
Common Securities are transferable on the books and records of the Trust, in
person or by a duly authorized attorney, upon surrender of this certificate
duly endorsed and in proper form for transfer.  The designation, rights,
privileges, restrictions, preferences and other terms and provisions of the
Common Securities represented hereby are issued and shall in all respects be
subject to the provisions of the Amended and Restated Declaration of Trust of
the Trust dated as of ____________________, ____, as the same may be amended
from time to time (the "Declaration"), including the designation of the terms
of the Common Securities as set forth in Exhibit A to the Declaration.
Capitalized terms used herein but not defined shall have the meaning given them
in the Declaration.

         The Holder is entitled to the benefits of the Common Securities
Guarantee to the extent provided therein.  The Trust will provide a copy of the
Declaration, the Common Securities Guarantee and the Indenture to the Holder
without charge upon written request to the Trust at its principal place of
business.

         Upon receipt of this certificate, the Sponsor is bound by the
Declaration and is entitled to the benefits thereunder.

         By acceptance, the Holder agrees to treat for United States federal
income tax purposes the Notes as indebtedness and the Common Securities as
evidence of indirect beneficial ownership in the Notes.





                                      II-1
<PAGE>   80
         IN WITNESS WHEREOF, the Trust has executed this certificate this _____
day of _______________, 199___.

                                           George C. Biehl
                                           as Trustee



                                           -------------------------------
                                                                         



                                           Jeffrey W. Shaw
                                           as Trustee



                                           -------------------------------
                                                                         





                                      II-2
<PAGE>   81
                                   ASSIGNMENT


FOR VALUE RECEIVED, the undersigned assigns and transfers this Preferred
Security Certificate to:

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
(Insert assignee's social security or tax identification number)


- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
(Insert address and zip code of assignee) and irrevocably appoints)

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
agent to transfer this Preferred Security Certificate on the books of the Trust.
The agent may substitute another to act for him or her.

Date:
     -------------------------

Signature:
          -----------------------------------
(Sign exactly as your name appears on the other side of this Preferred Security
Certificate)





                                      II-3

<PAGE>   1

                                                                 EXHIBIT 5.1


                                 [LETTERHEAD]



                                                                

                                   October
                                   6th
                                   1 9 9 5


(213) 669-6000                                                      815,040-023 


Southwest Gas Corporation
5241 Spring Mountain Road
Las Vegas, Nevada 89102


         Re:  $270,400,000 Aggregate Offering Price of Securities of
              Southwest Gas Corporation and Southwest Gas Capital I
              ------------------------------------------------------


Ladies and Gentlemen:

        At your request, we have examined Amendment No. 1 to the Registration
Statement on Form S-3, File No. 33-62143, as amended (the "Registration
Statement"), to be filed by Southwest Gas Corporation (the "Company") and
Southwest Gas Capital I (the "Trust") with the Securities and Exchange
Commission in connection with the registration of $270,400,000 aggregate
offering price of securities (the "Securities"), consisting of one or more
series of unsecured debt securities (the "Debt Securities"), which may be
issued in the form of senior Debt Securities or subordinated Debt Securities;
one or more series of shares of preferred stock, par value $1.00 per share (the
"Preferred Stock"); depositary shares representing interests in the Preferred
Stock (the "Depositary Shares"); shares of common stock, par value $1.00 per
share (the "Common Stock") preferred securities of the Trust (the "Preferred
Securities"); and the guarantee of Preferred Securities of the Trust, including
certain back-up undertakings (the "Guarantee"). We are familiar with the
proceedings heretofore taken by the Company and the Trust in connection with
the authorization, registration, issuance and sale of the Securities.

<PAGE>   2
Page 2 - Southwest Gas Corporation - October 6, 1995

        Subject to (i) the proposed additional proceedings being taken as now
contemplated by us as your counsel prior to the issuance of the Securities;
(ii) the effectiveness of the Registration Statement under the Securities Act
of 1933, as amended; (iii) the due authorization, execution and delivery of the
indentures relating to the Debt Securities and the establishment of the terms
of the senior Debt Securities or subordinated Debt Securities, as applicable,
in accordance with the terms of the form of Indenture relating to the senior
Debt Securities and the Indenture relating to the subordinated Debt Securities,
respectively; (iv) the establishment of the terms of the Preferred Stock, if
applicable, in accordance with the terms of the Company's Restated Articles of
Incorporation and applicable law; (v) the due, authorization, execution and
delivery of a Deposit Agreement (in the case of Depositary Shares) and the
Guarantee (in the case of Preferred Securities); (vi) the due, authorization,
execution and delivery of the Amended and Restated Declaration of the Trust and
establishment of the terms of the Preferred Securities, if applicable, in
accordance with the terms of the Amended and Restated Declaration of the Trust;
and (vii) the execution, delivery and authentication of and payment for the
Securities, it is our opinion that:

                1.      The Debt Securities will, upon the issuance and sale 
        thereof in the manner referred to in the Registration Statement, 
        constitute legally valid and binding obligations of the Company,
        enforceable against the Company in accordance with their terms, except
        as may be limited by bankruptcy, insolvency, reorganization, moratorium
        or similar laws relating to or affecting creditors' rights generally
        (including, without limitation, fraudulent conveyance laws) and by
        general principles of equity including, without limitation, concepts of
        materiality, reasonableness, good faith and fair dealing and the
        possible unavailability of specific performance or injunctive relief,
        regardless of whether considered in a proceeding in equity or at law.

                2.      The Preferred Stock will, upon the issuance and sale 
        thereof in the manner referred to in the Registration Statement, be
        validly issued, fully paid and nonassessable.


                3.      The persons in whose names the Depositary Shares 
        represented by depositary receipts are registered will be entitled
        to the rights specified in the Deposit Agreement.






<PAGE>   3
Page 3 - Southwest Gas Corporation - October 6, 1995

                4.      The Common Stock, including any Common Stock that may be
        issuable pursuant to the conversion of any Debt Securities or Preferred
        Stock will, upon the issuance and sale thereof in the manner specified
        in the Registration Statement, be validly issued, fully paid and
        nonassessable.

                5.      The Guarantee will, upon the execution thereof and the
        issuance and sale of the Preferred Securities and other securities to
        be issued in connection therewith in the manner referred to in the
        Registration Statement, constitute the legally valid and binding
        obligation of the Company, enforceable against the Company in
        accordance with its terms, except as may be limited by bankruptcy,
        insolvency, reorganization, moratorium or similar laws relating to
        affecting creditor's rights generally (including, without limitation,
        fraudulent conveyance laws), by general principles of equity including,
        without limitation, concepts of materiality, reasonableness, good faith
        and fair dealing and the possible unavailability of specific
        performance or injunctive relief, regardless of whether considered in a
        proceeding in equity or at law and by the unenforceability under
        certain circumstances of waivers of rights granted by law where the
        waivers are against public policy or prohibited by law.

        We consent to the filing of this opinion as an exhibit to the
Registration Statement.

                                        Respectfully submitted,


                                        O'MELVENY & MYERS                     
                   

<PAGE>   1

                                                                    EXHIBIT 5.2


                             [SKADDEN LETTERHEAD]


                               October 6, 1995



Southwest Gas Capital I
c/o Southwest Gas Corporation
5241 Spring Mountain Road
P.O. Box 98510
Las Vegas, Nevada 89153-7173

           Re:  Southwest Gas Corporation;
                Southwest Gas Capital I;
                Registration Statement on Form S-3
                Registration No. 33-62143
                ----------------------------------

Ladies and Gentlemen:

        We have acted as special counsel to Southwest Gas Capital I, a
statutory business trust formed under the laws of the State of Delaware (the
"Trust"), in connection with the preparation of a Registration Statement on
Form S-3 (Registration No. 33-62143), filed by Southwest Gas Corporation (the
"Company") and the Trust with the Securities and Exchange Commission (the
"Commission") on August 25, 1995 under the Securities Act of 1933, as amended
(the "Act"), and Amendment No. 1 thereto, filed with the Commission on October
6, 1995 (such Registration Statement, as so amended, being hereinafter referred
to as the "Registration Statement"), relating to the registration under the Act
of the preferred securities (the "Preferred Securities") of the Trust.

        The Preferred Securities are to be issued pursuant to the Amended and
Restated Declaration of Trust (the "Declaration") among the Company, as
sponsor, and Wilmington Trust Company, as the property trustee (the "Property
Trustee") and George C. Biehl and Jeffrey W. Shaw, as regular trustees
(together, the "Regular Trustees"). Capitalized terms used but not otherwise
defined herein have the meanings ascribed to them in the Registration
Statement.



<PAGE>   2
Page 2 - Southwest Gas Capital I - October 6, 1995


        This opinion is being delivered in accordance with the requirements of 
Item 601(b)(5) of Regulation S-K under the Act.

        In connection with this opinion, we have examined originals or copies,
certified or otherwise identified to our satisfaction, of (i) the certificate
of trust (the "Certificate of Trust") filed by the Property Trustee and the
Regular Trustees with the Secretary of State of the State of Delaware on 
August 17, 1995; (ii) the form of the Declaration (including the form of the
terms of the Preferred Securities. We have also examined originals or copies,
certified or otherwise identified to our satisfaction, of such other documents,
certificates and records as we have deemed necessary or appropriate as a basis
for the opinions set forth herein.

        In our examination, we have assumed the legal capacity of all natural
persons, the genuineness of all signatures, the authenticity of all documents
submitted to us as originals, the conformity to original documents of all
documents submitted to us as certified or photostatic copies and the
authenticity of the originals of such copies. In making our examination of
documents executed by parties other than the Trust, we have assumed that such
parties had the power, corporate or other, to enter into and perform all
obligations thereunder and have also assumed the due authorization by all
requisite action, corporate or other, and execution and delivery by such
parties of such documents and that such documents constitute valid and binding
obligations of such parties. In addition, we have assumed that each of the
Declaration and the Preferred Securities as executed will be in form reviewed
by us.  As to any facts material to the opinions expressed herein which were
not independently established or verified, we have relied upon oral or written
statements and representations of officers, trustees and other representatives
of the Company, the Trust and others.

        Members of our firm are admitted to the bar in the State of Delaware,
and we express no opinion as to the laws of any other jurisdiction other than
the laws of the United States of America to the extent specifically referred to
herein.

        Based on and subject to the foregoing and to the other qualifications
and limitations set forth herein, we are of the opinion that the Preferred
Securities, when the Declaration is executed and delivered and the terms of the
Preferred Securities are established in accordance with the terms of the
Declaration, will be duly authorized for issuance and, when issued and executed
in accordance with the Declaration and delivered and

<PAGE>   3
Page 3 - Southwest Gas Corporation Capital I - October 6, 1995


paid for as set forth in the form of Prospectus Supplement included as an
Exhibit to the Registration Statement, will be validly issued, fully paid and
nonassessable, representing undivided beneficial interests in the assets of
Trust. We bring to your atttention that the Preferred Securities holders may be
obligated, pursuant to the Trust Declaration, to (i) provide indemnity and/or
security in connection with and pay taxes or governmental charges arising from
transfers of Preferred Securities and (ii) provide security and indemnity in
connection with the requests of or directions to the Property Trustee to
exercise its rights and powers under the Declaration.

        This opinion is furnished to you solely for your benefit in connection
with the filing of the Registration Statement and, except as set forth in the
next sentence, is not to be used, circulated, quoted or otherwise referred to
for any other purppose or relied upon by any other person for any purpose
without our prior written consent. We also consent to the use of our name under
the heading "Legal Matters" in the form of Prospectus Supplement included as an
exhibit to the Registration Statement. We hereby consent to the filing of this
opinion with the Commission as Exhibit 5.2 to the Registration Statement. In
giving this consent, we do not thereby admit that we are within the category of
persons whose consent is required under Section 7 of the Act or the rules and
regulations of the Commission promulgated thereunder. This opinion is expressed
as of the date hereof unless otherwise expressly stated and we disclaim any
understanding to advise you of any subsequent changes of the facts stated or
assumed herein or any subsequent changes in applicable law.




                                       Very truly yours,


                                       /s/ Skadden, Arps, Slate, Meagher & Flom


<PAGE>   1
 
                                                                   EXHIBIT 23.01
 
                   CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS
 
   
As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement (No. 33-62143) of our report dated
February 8, 1995, included in Southwest Gas Corporation's Form 10-K for the year
ended December 31, 1994, and to all references to our Firm included in this
registration statement.
    
 
                                          ARTHUR ANDERSEN LLP
 
Las Vegas, Nevada
   
October 4, 1995
    

<PAGE>   1
                                Exhibit 99.01

     INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A
REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR MAY ANY
OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT BECOMES
EFFECTIVE. THIS PROSPECTUS SHALL NOT CONSTITUTE AN OFFER TO SELL OR THE
SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF THESE SECURITIES
IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD BE UNLAWFUL PRIOR
TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS OF ANY SUCH STATE.

(SUBJECT TO COMPLETION, ISSUED          ,     )
                               ------ --  ----

PROSPECTUS SUPPLEMENT

(To Prospectus Dated             ,     )
                     ------------  ----

                                         Preferred Securities
                              ----------

                                  Southwest Gas Capital I
____%  Trust Originated Preferred Securities(sm) ("TOPrS(sm)")
             (Liquidation amount $25 per Preferred Security)
             guaranteed to the extent set forth herein by

                            SOUTHWEST GAS CORPORATION

                              --------------------

         The _____% Trust Originated Preferred Securities (the "Preferred
Securities") offered hereby represent preferred undivided beneficial interests
in the assets of Southwest Gas Capital I, a statutory business trust formed
under the laws of the State of Delaware (the "Trust"). Southwest Gas
Corporation, a California corporation (the "Company"), will own all the common
securities (the "Common Securities" and, together with the Preferred Securities,
the "Trust Securities") representing undivided beneficial interests in the
assets of the Trust. The Trust exists for the sole purpose of issuing the
Preferred Securities and Common

Securities and investing the proceeds thereof in an equivalent amount of ____%
Subordinated Deferrable Interest Notes due ____ [30 years after issuance]
(the "Subordinated Debt Securities") of the Company. Upon an event of a 
default under the Declaration (as defined herein), the holders of Preferred 
Securities will have a preference over the holders of the Common Securities 
with respect to payments in respect of distributions and payments upon 
redemption, liquidation and otherwise.

                                                        (continued on next page)

                           ---------------------------

         See "Risk Factors" commencing on page ___ hereof for certain
information relevant to an investment in the Preferred Securities, including the
period and circumstances during and under which payments of distributions on the
Preferred Securities may be deferred and the related United States federal
income tax consequences of such deferral.

         The Preferred Securities have been approved for listing upon notice of
issuance on the New York Stock Exchange, Inc. (the "New York Stock Exchange").
Trading of the Preferred Securities on the New York Stock Exchange is expected
to commence within a 30-day period after the initial delivery of the Preferred
Securities. See "Underwriting."


<PAGE>   2

THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS SUPPLEMENT OR THE PROSPECTUS TO WHICH IT
RELATES. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

<TABLE>
<CAPTION>
                                                                                            Proceeds to the
                                               Initial Public         Underwriting               Trust
                                             Offering Price (1)      Commission (2)             (3) (4)
<S>                                          <C>                     <C>                    <C>   
 Per Preferred Security  . . . . . . .             $25.00                  (3)                  $25.00
 Total(5)  . . . . . . . . . . . . . .          $____________              (3)               $____________
</TABLE>

(1)      Plus accrued distributions, if any, from the date of initial issuance.

(2)      The Trust and the Company have agreed to indemnify the several
         Underwriters against certain liabilities, including liabilities under
         the Securities Act of 1933, as amended. See "Underwriting."

(3)      Because the proceeds of the sale of the Preferred Securities will be
         used to purchase Subordinated Debt Securities, the Company has agreed,
         in the Underwriting Agreement, to pay to the Underwriters as
         compensation ("Underwriters' Compensation") for their services $____
         per Preferred Security (or $____________ in the aggregate); provided,
         that such compensation for sales of 10,000 or more Preferred Securities
         to a single purchaser will be $______ per Preferred Security.
         Therefore, to the extent of such sales, the actual amount of
         Underwriters' Compensation will be less than the aggregate amount
         specified in the preceding sentence. See "Underwriting."

(4)      Expenses of the offering, which are payable by the Company, are
         estimated to be $____________.

(5)      The Trust and the Company have granted the Underwriters an option for
         30 days to purchase up to an additional _______ Preferred Securities at
         the initial public offering price per Preferred Security solely to
         cover over-allotments, if any. The Company will pay to the
         Underwriters, as Underwriters' Compensation, the commission set forth
         in Note 3 for any Preferred Security purchased pursuant to this option.
         If such option is exercised in full, the total initial public offering
         price, full Underwriters' Compensation, and proceeds to the Trust will
         be $__________, $___________, and $__________, respectively. See
         "Underwriting".

         The Preferred Securities offered hereby are offered severally by the
Underwriters, as specified herein, subject to receipt and acceptance by them and
subject to their right to reject any order in whole or in part. It is expected
that delivery of the Preferred Securities will be made only in book-entry form
through the facilities of The Depository Trust Company, on or about
__________, ____.
                              --------------------

<PAGE>   3



                               Merrill Lynch & Co.

                          [Other Underwriters to come]

                              --------------------

         The date of this Prospectus Supplement is ____________, ___.

           (sm)"Trust Originated Preferred Securities" and "TOPrS" are
                      service marks of Merrill Lynch & Co.

(continued from previous page)

         Holders of the Preferred Securities are entitled to receive cumulative
cash distributions at an annual rate of ____% of the liquidation amount of $25
per Preferred Security, accruing from the date of original issuance and payable
quarterly in arrears on March 31, June 30, September 30 and December 31 of each
year, commencing __________, ____ ("distributions"). The payment of
distributions out of moneys held by the Trust and payments on liquidation of the
Trust or the redemption of Preferred Securities, as set forth below, are
guaranteed by the Company (the "Guarantee") to the extent described under
"Description of the Guarantee" in the accompanying Prospectus. The obligations
of the Company under the Guarantee are subordinate and junior in right of
payment to all other liabilities of the Company and pari passu with the most
senior preferred stock issued, from time to time, if any, by the Company. The
obligations of the Company under the Subordinated Debt Securities are
subordinate and junior in right of payment to all present and future Senior
Indebtedness (as defined herein) of the Company, which aggregated approximately
$____ million at ____________, ____, and rank pari passu with the Company's
other general unsecured creditors.

         The distribution rate and the distribution and other payment dates for
the Preferred Securities will correspond to the interest rate and interest and
other payment dates on the Subordinated Debt Securities, which will be the sole
assets of the Trust. As a result, if principal or interest is not paid on the
Subordinated Debt Securities, no amounts will be paid on the Preferred
Securities. If the Company does not make principal or interest payments on the
Subordinated Debt Securities, the Trust will not have sufficient funds to make
distributions on the Preferred Securities, in which event, the Guarantee will
not apply to such distributions until the Trust has sufficient funds available
therefor.

         The Company has the right to defer payments of interest on the
Subordinated Debt Securities by extending the interest payment period on the
Subordinated Debt Securities at any time for up to 20 consecutive quarters
(each, an "Extension Period"). If interest payments are so deferred,
distributions will also be deferred. During such Extension Period, distributions
will continue to accrue with interest thereon (to the extent permitted by
applicable law) at an annual rate of ____% per annum compounded quarterly.
During any Extension Period, holders of Preferred Securities will be required to
include deferred interest income in their gross income for United States federal
income tax purposes in advance of the

                                       S-3


<PAGE>   4



receipt of the cash distributions with respect to such deferred interest
payments. There could be multiple Extension Periods of varying lengths
throughout the term of the Subordinated Debt Securities. If the Company
exercises the right to extend an interest payment period, the Company shall not
during such Extension Period (i) declare or pay dividends on, or make a
distribution with respect to, or redeem, purchase or acquire or make a
liquidation payment with respect to, any of its capital stock, or (ii) make any
payment of interest, principal or premium, if any, on or repay, repurchase or
redeem any debt securities issued by the Company that rank pari passu with or
junior to the Subordinated Debt Securities; provided, however, that restriction
(i) above does not apply to any stock dividends paid by the Company where the
dividend stock is the same as that on which the dividend is being paid. The
Company has no present intention of exercising its right to extend an interest
payment period. See "Description of the Subordinated Debt Securities -- Option
to Extend Interest Payment Period." See "Risk Factors -- Option to Extend
Interest Payment Period and Defer Payment of Interest" and "United States
Federal Income Taxation -- Original Issue Discount."

        The Subordinated Debt Securities are redeemable by the Company, in
whole or in part, from time to time, on or after ____________, ____ [five years
after issuance of the Subordinated Debt Securities], or at any time in certain
circumstances upon the occurrence of a Tax Event (as defined herein). If the
Company redeems Subordinated Debt Securities, the Trust must redeem Trust
Securities having an aggregate liquidation amount equal to the aggregate
principal amount of the Subordinated Debt Securities so redeemed at $25 per
Preferred Security plus accrued and unpaid distributions thereon, including
interest thereon, to the date fixed for redemption (the "Redemption Price").
See "Description of the Preferred Securities -- Mandatory Redemption." The
Preferred Securities will be redeemed upon maturity of the Subordinated Debt
Securities. The Subordinated Debt Securities mature on ____________, ____ [30
years after issuance of the Subordinated Debt Securities], but the maturity
date may be extended only once, for up to an additional 19 years at the option
of the Company, provided certain financial conditions are met. See "Description
of the Subordinated Debt Securities -- Option to Extend Maturity Date" In
addition, upon the occurrence of a Tax Event arising from a change in law or a
change in legal interpretation regarding tax matters, unless the Subordinated
Debt Securities are redeemed in the limited circumstances described herein, the
Trust will be dissolved with the result that the Subordinated Debt Securities
will be distributed to the holders of the Preferred Securities, on a pro rata
basis, in lieu of any cash distribution. See "Description of the Preferred
Securities -- Tax Event Redemption or Distribution." In certain circumstances,
the Company will have the right to redeem the Subordinated Debt Securities,
which would result in the redemption by the Trust of Trust Securities in the
same amount on a pro rata basis. If the Subordinated Debt Securities are
distributed to the holders of the Preferred Securities, the Company will use
its best efforts to have the Subordinated Debt Securities listed on the New
York Stock Exchange or on such other exchange or organization as the Preferred
Securities are then listed. See "Description of the Preferred Securities -- Tax
Event Redemption or Distribution" and "Description of the Subordinated Debt
Securities."

                                       S-4


<PAGE>   5



         In the event of the involuntary or voluntary dissolution, winding up or
termination of the Trust, the holders of the Preferred Securities will be
entitled to receive for each Preferred Security a liquidation amount of $25 plus
accrued and unpaid distributions thereon (including interest thereon) to the
date of payment, unless, in connection with such dissolution, the Subordinated
Debt Securities are distributed to the holders of the Preferred Securities. See
"Description of the Preferred Securities -- Liquidation Distribution Upon
Dissolution."

         IN CONNECTION WITH THIS OFFERING, THE UNDERWRITERS MAY OVER-ALLOT OR
EFFECT TRANSACTIONS THAT STABILIZE OR MAINTAIN THE MARKET PRICE OF THE
SECURITIES OFFERED HEREBY AT LEVELS ABOVE THOSE THAT MIGHT OTHERWISE PREVAIL IN
THE OPEN MARKET. SUCH TRANSACTIONS MAY BE EFFECTED ON THE NEW YORK STOCK
EXCHANGE, IN THE OVER-THE-COUNTER MARKET OR OTHERWISE. SUCH STABILIZING
TRANSACTIONS, IF COMMENCED, MAY BE DISCONTINUED AT ANY TIME.

                                       S-5


<PAGE>   6



                          SUMMARY FINANCIAL INFORMATION

         The following selected financial information should be read in
conjunction with the financial statements and notes thereto incorporated by
reference into this Prospectus Supplement and the accompanying Prospectus.

                                        

   
<TABLE>
<CAPTION>

                                      
                                         
                                     Twelve Months                          Year Ended December 31,
                                     Ended _______                       ----------------------------
                                                       ------       ----------        ------      ----------
                                                        (DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                   <C>              <C>          <C>               <C>         <C>
</TABLE>


<TABLE>
<CAPTION>
                                                                          As of ____________, ____                 
                                                             ------------------------------------------------------
                                                                    Actual                      As Adjusted (1)    
                                                             -----------------------        -----------------------
                                                             Amount       Percentage        Amount      Percentage 
                                                             ------       ----------        ------      ---------- 
                                                                              (DOLLARS IN THOUSANDS)               
<S>                                                          <C>          <C>               <C>         <C>        
   BALANCE SHEET DATA:
   Total assets  
   Short-term borrowings (2)                    
   Long-term debt, including current maturities(2)

   Company Obligated Mandatorily Redeemable 
   Preferred Securities of Southwest Gas Capital I (3) ...
   Mandatory Redeemable Preferred Stock ..................
   Stockholders' equity:
</TABLE>
    

                                       S-6


<PAGE>   7



<TABLE>
<CAPTION>
                                                                    As of ____________, ____
                                                       ------------------------------------------------------
                                                              Actual                      As Adjusted (1)
                                                       -----------------------        -----------------------
                                                       Amount       Percentage        Amount      Percentage
                                                       ------       ----------        ------      ----------

<S>                                                    <C>          <C>               <C>         <C>           
   Common stock and additional paid-in
   capital . . . . . . . . . . . . . .
   Unrealized gain/loss, net of tax, on debt
   securities available for sale (4) .
   Retained earnings . . . . . . . . .
Total stockholders' equity  . . . . . .
   Total capitalization  . . . . . . .
</TABLE>

(1)      Adjusted for the sale of _____ Preferred Securities (assuming the
         Underwriters' over-allotment option is not exercised) and $____ million
         of Subordinated Debt Securities and the application of the estimated
         net proceeds from the sale of the Subordinated Debt Securities to
         _______________.

(2)      Excludes the Bank's deposit liabilities, securities sold under
         agreements to repurchase and Federal Home Loan Bank advances.

   
(3)      As described in this Prospectus Supplement, the sole asset of the Trust
         (which is a subsidiary trust of the Company) will be approximately
         $____ million of Subordinated Debt Securities of the Company which will
         bear interest at the rate of ____% per annum, assuming the issuance of
         _____ million Preferred Securities. The obligations of the Company
         under the Declaration, the Guarantee, the Indenture (as defined
         herein) and the Subordinated Debt Securities collectively provide a
         full and unconditional guarantee on a subordinated basis of payments
         due on the Preferred Securities, to the extent the Trust has funds
         available therefor as a result of payments of interest or principal on
         the Subordinated Debt Securities by the Company.
    

(4)      Securities classified as available for sale are those which the Bank
         intends to hold for an indefinite period and which may be sold in
         response to changes in market interest rates, changes in the security's
         prepayment risk, the Bank's need for liquidity, changes in the
         availability and yield of alternative investments, and other
         asset/liability management needs. Securities classified as available
         for sale are stated at fair value in consolidated financial statements
         filed with the Securities and Exchange Commission (the "Commission").
         Unrealized gains or losses on debt securities available for sale are
         reported net of tax as a separate component of stockholders' equity,
         but are not included in net income. Realized gains or losses are
         recorded into income if and when the securities are sold.

         The following information concerning the Company, the Trust, the
Preferred Securities, the Guarantee and the Subordinated Debt Securities
supplements, and should be read in conjunction with, the information contained
in the accompanying Prospectus.

                                  RISK FACTORS

         Prospective purchasers of Preferred Securities should carefully review
the information contained elsewhere in this Prospectus Supplement and in the
accompanying Prospectus and should particularly consider the following matters.

                                       S-7


<PAGE>   8



RANKING OF SUBORDINATE OBLIGATIONS UNDER THE SUBORDINATED DEBT SECURITIES AND
THE GUARANTEE

         The obligations of the Company under the Subordinated Debt Securities
are subordinate and junior in right of payment to all present and future Senior
Indebtedness of the Company and pari passu with obligations to, or rights of,
the Company's other general unsecured creditors. The Company's obligations under
the Guarantee are subordinate and junior in right of payment to all liabilities
of the Company and pari passu with the most senior preferred stock issued, from
time to time, if any, by the Company. As of ___________, ____, Senior
Indebtedness aggregated approximately $___ million. There are no terms in the
Preferred Securities, the Subordinated Debt Securities or the Guarantee that
limit the Company's ability to incur additional indebtedness, including
indebtedness that ranks senior to the Subordinated Debt Securities and the
Guarantee. See "Description of the Guarantee" and "Particular Terms of the
Subordinated Debt Securities Issued in Connection with the Preferred Securities"
in the accompanying Prospectus and "Description of the Subordinated Debt
Securities - Subordination" herein.

RIGHTS UNDER THE GUARANTEE

         The Guarantee will be qualified as an indenture under the Trust
Indenture Act of 1939, as amended (the "Trust Indenture Act"). Harris Trust and
Savings Bank will act as indenture trustee under the Guarantee for the purposes
of compliance with the provisions of the Trust Indenture Act (the "Guarantee
Trustee"). The Guarantee Trustee will hold the Guarantee for the benefit of the
holders of the Preferred Securities.

   
         The Guarantee guarantees to the holders of the Preferred Securities the
payment of (i) any accrued and unpaid distributions that are required to be paid
on the Preferred Securities, to the extent the Company has made a payment of
principal or interest on the Subordinated Debt Securities, (ii) the Redemption
Price, including all accrued and unpaid distributions with respect to Preferred
Securities called for redemption by the Trust, to the extent the Company has
made a payment of principal and interest on the Subordinated Debt Securities,
and (iii) upon a voluntary or involuntary dissolution, winding-up or termination
of the Trust (other than in connection with the distribution of Subordinated
Debt Securities to the holders of Preferred Securities or a redemption of all
the Preferred Securities upon the maturity or redemption of the Subordinated
Debt Securities), the lesser of (a) the aggregate of the liquidation amount and
all accrued and unpaid distributions (including interest thereon) on the
Preferred Securities to the date of payment to the extent the Trust has funds
available therefor or (b) the amount of assets of the Trust remaining available
for distribution to holders of the Preferred Securities in liquidation of the
Trust. The holders of a majority in liquidation amount of the Preferred
Securities have the right to direct the time, method and place of conducting any
proceeding for any remedy available to the Guarantee Trustee or to direct the
exercise of any trust or power conferred upon the Guarantee Trustee under the
Guarantee. If the Guarantee Trustee fails to enforce the Guarantee, any holder
of Preferred Securities may institute a legal proceeding directly against 
the Company to enforce the
    

                                       S-8


<PAGE>   9



Guarantee Trustee's rights under the Guarantee without first instituting a legal
proceeding against the Trust, the Guarantee Trustee or any other person or
entity. If the Company were to default on its obligation to pay amounts payable
on the Subordinated Debt Securities, the Trust would lack available funds for
the payment of distributions or amounts payable on redemption of the Preferred
Securities or otherwise, and, in such event, holders of the Preferred Securities
would not be able to rely upon the Guarantee for payment of such amounts.
Instead, holders of the Preferred Securities would be required to rely on the
enforcement by the Property Trustee of its rights as registered holder of the
Subordinated Debt Securities against the Company pursuant to the terms of the
Subordinated Debt Securities or, if the Property Trustee fails to enforce such
rights after written notice, on the holder's right to institute a suit against
the Company to enforce the Property Trustee's rights. See "Description of the
Guarantee" and "Particular Terms of the Subordinated Debt Securities Issued in
Connection with the Preferred Securities" in the accompanying Prospectus. The
Declaration provides that each holder of Preferred Securities, by acceptance
thereof, agrees to the provisions of the Guarantee, including the subordination
provisions thereof, and the Indenture (as such term is defined in "Description
of Subordinated Debt Securities" herein).

ENFORCEMENT OF CERTAIN RIGHTS BY HOLDERS OF PREFERRED SECURITIES

   
         The holders of a majority in aggregate liquidation amount of the
Preferred Securities will have the right to direct the time, method, and place
of conducting any proceeding for any remedy available to the Property Trustee or
to direct the exercise of any trust or power conferred upon the Property Trustee
under the Declaration, including the right to direct the Property Trustee to
exercise the remedies available to it as a holder of the Subordinated Debt
Securities. If the Property Trustee fails to enforce its rights under the
Subordinated Debt Securities, a holder of Preferred Securities may institute 
a legal proceeding directly against the Company to enforce the Property 
Trustee's rights under the Subordinated Debt Securities without first 
instituting any legal proceeding against the Property Trustee or any other
person or entity.
    

OPTION TO EXTEND INTEREST PAYMENT PERIOD

         The Company has the right under the Indenture to defer payments of
interest on the Subordinated Debt Securities by extending the interest payment
period at any time, and from time to time, on the Subordinated Debt Securities.
As a consequence of such an extension, quarterly distributions on the Preferred
Securities would be deferred (but despite such deferral would continue to accrue
with interest thereon compounded quarterly) by the Trust during any such
extended interest payment period. Such right to extend the interest payment
period for the Subordinated Debt Securities is limited to a period not exceeding
20 consecutive quarters (each, an "Extension Period"). In the event that the
Company exercises this right to defer interest payments, then (i) the Company
must not declare or pay dividends on, or make a distribution with respect to, or
redeem, purchase or acquire, or make a liquidation payment with respect to, any
of its capital stock and (ii) the Company must not

                                       S-9


<PAGE>   10



make any payment of interest, principal or premium, if any, on or repay,
repurchase or redeem any debt securities issued by the Company that rank pari
passu with or junior to the Subordinated Debt Securities; provided, however,
that restriction (i) above does not apply to any stock dividends paid by the
Company, where the dividend stock is the same stock as that on which the
dividend is being paid. Prior to the termination of any such Extension Period,
the Company may further extend the interest payment period; provided that, such
Extension Period, together with all such previous and further extensions within
such Extension Period, may not exceed 20 consecutive quarters. Upon the
termination of any Extension Period and the payment of all amounts then due, the
Company may commence a new Extension Period, subject to the above requirements.
See "Description of the Preferred Securities -- Distributions" and "Description
of the Subordinated Debt Securities -- Option to Extend Interest Payment
Period."

         Should the Company exercise its right to defer payments of interest by
extending the interest payment period, each holder of Preferred Securities will
continue to accrue income (as original issue discount ("OID")) in respect of the
deferred interest allocable to its Preferred Securities for United States
federal income tax purposes, which will be allocated but not distributed to
holders of record of Preferred Securities. As a result, each such holder of
Preferred Securities will recognize income for United States federal income tax
purposes in advance of the receipt of cash and will not receive the cash from
the Trust related to such income if such holder disposes of its Preferred
Securities prior to the record date for the date on which distributions of such
amounts are made. The Company has no current intention of exercising its right
to defer payments of interest by extending the interest payment period on the
Subordinated Debt Securities. However, should the Company determine to exercise
such right in the future, the market price of the Preferred Securities is likely
to be affected. A holder that disposes of its Preferred Securities during an
Extension Period, therefore, might not receive the same return on its investment
as a holder that continues to hold its Preferred Securities. In addition, as a
result of the Company's right to defer interest payments, the market price of
the Preferred Securities (which represent an undivided beneficial interest in
the Subordinated Debt Securities) may be more volatile than other securities on
which OID accrues but with respect to which there is no right to defer interest
payments. See "United States Federal Income Taxation -- Original Issue
Discount."

TAX EVENT REDEMPTION OR DISTRIBUTION

         Upon the occurrence of a Tax Event (as defined herein), the Trust will
be dissolved, except in the limited circumstance described below, with the
result that the Subordinated Debt Securities will be distributed to the holders
of the Trust Securities in connection with the liquidation of the Trust. In
certain circumstances, the Company has the right to redeem the Subordinated Debt
Securities, in whole or in part, in lieu of a distribution of the Subordinated
Debt Securities by the Trust, in which event the Trust will redeem the Trust
Securities on a pro rata basis to the same extent as the Subordinated Debt
Securities are redeemed by the Company. See "Description of the Preferred
Securities - Tax Event Redemption or Distribution."

                                      S-10


<PAGE>   11



         Under current United States federal income tax law, a distribution of
Subordinated Debt Securities upon the dissolution of the Trust would not be a
taxable event to holders of the Preferred Securities. Upon occurrence of a Tax
Event, however, a dissolution of the Trust pursuant to which holders of the
Preferred Securities receive cash would be a taxable event to such holders. See
"United Stated Federal Income Taxation -- Receipt of Subordinated Debt
Securities or Cash Upon Liquidation of the Trust."

         There can be no assurance as to the market prices for the Preferred
Securities or the Subordinated Debt Securities that may be distributed in
exchange for Preferred Securities if a dissolution or liquidation of the Trust
were to occur. Accordingly, the Preferred Securities that an investor may
purchase, whether pursuant to the offer made hereby or in the secondary market,
or the Subordinated Debt Securities that a holder of Preferred Securities may
receive on dissolution and liquidation of the Trust, may trade at a discount to
the price that the investor paid to purchase the Preferred Securities offered
hereby. Because holders of Preferred Securities may receive Subordinated Debt
Securities upon the occurrence of a Tax Event, prospective purchasers of
Preferred Securities are also making an investment decision with regard to the
Subordinated Debt Securities and should carefully review all the information
regarding the Subordinated Debt Securities contained herein and in the
accompanying Prospectus. See "Description of the Preferred Securities -- Tax
Event Redemption or Distribution" and "Description of the Subordinated Debt
Securities -- General."

LIMITED VOTING RIGHTS

         Holders of Preferred Securities will have limited voting rights and
will not be entitled to vote to appoint, remove or replace, or to increase or
decrease the number of, the Regular Trustees, which voting rights are vested
exclusively in the holder of the Common Securities.

TRADING PRICE

         The Preferred Securities may trade at a price that does not fully
reflect the value of accrued but unpaid interest with respect to the underlying
Subordinated Debt Securities. A holder who disposes of Preferred Securities
between record dates for payments of distributions thereon will be required to
include accrued but unpaid interest on the Subordinated Debt Securities through
the date of disposition as ordinary income (i.e., OID), and to add such amount
to the adjusted tax basis of such Holder's pro rata share of the underlying
Subordinated Debt Securities deemed disposed of. To the extent the selling price
is less than the holder's adjusted tax basis (which will include, in the form of
OID, all accrued but unpaid interest), a holder will recognize a capital loss.
Subject to certain limited exceptions, capital losses cannot be applied to
offset ordinary income for United States federal income tax purposes. See
"United States Federal Income Taxation -- Original Issue Discount" and "Sales of
Preferred Securities."

                                      S-11


<PAGE>   12



                            RECENT OPERATING RESULTS

                                    [To Come]

                                   THE COMPANY

                                    [To Come]

NATURAL GAS SEGMENT

                                    [To Come]

FINANCIAL SERVICES SEGMENT

                                    [To Come]

                   CAPITAL EXPENDITURES AND FINANCING PROGRAMS

                                    [To Come]


                                    THE TRUST

         The Trust is a statutory business trust formed under Delaware law
pursuant to (i) a declaration of trust, dated as of August 17, 1995, executed by
the Company, as sponsor (the "Sponsor"), and the trustees of the Trust and (ii)
the filing of a certificate of trust with the Secretary of State of the State of
Delaware on August 17, 1995. Such declaration will be amended and restated in
its entirety (as so amended and restated, the "Declaration") substantially in
the form filed as an exhibit to the Registration Statement of which this
Prospectus Supplement and the accompanying Prospectus form a part. The
Declaration will be qualified as an indenture under the Trust Indenture Act.
Upon issuance of the Preferred Securities, the purchasers thereof will own all
of the Preferred Securities. See "Description of the Preferred Securities --
Book-Entry Only Issuance -- The Depository Trust Company." The Company will
directly or indirectly acquire Common Securities in an aggregate liquidation
amount equal to 3% of the total capital of the Trust. The Trust exists for the
exclusive purposes of (i) issuing the Trust Securities representing undivided
beneficial interests in the assets of the Trust, (ii) investing the gross
proceeds of the Trust Securities in the Subordinated Debt Securities, and (iii)
engaging in only those other activities necessary or incidental thereto.

         Pursuant to the Declaration, the number of trustees of the Trust will
initially be four. Two of the trustees of the Trust (the "Regular Trustees")
will be persons who are employees or officers of, or who are affiliated, with
the Company. The third trustee, Wilmington Trust Company, is a financial
institution that maintains its principal place of business in the state of
Delaware and is unaffiliated with the Company. Except as otherwise provided in
the

                                      S-12


<PAGE>   13



Declaration, the Delaware Trustee's sole duty shall be to, upon the request of
the other Trustees or the Company, execute any documents and maintain custody of
any records required to maintain the existence of, or dissolve, the Trust under
the Trust Act. The fourth trustee, Harris Trust and Savings Bank, will serve as
property trustee under the Declaration and as indenture trustee for the purposes
of compliance with the provisions of the Trust Indenture Act (the "Property
Trustee"), until removed or replaced by the Company, as the holder of all the
Common Securities. Harris Trust and Savings Bank will also act as the Guarantee
Trustee. See "Description of the Guarantee" in the accompanying Prospectus.

         The Property Trustee will hold title to the Subordinated Debt
Securities for the benefit of the holders of the Trust Securities and will have
the power to exercise all rights, powers, and privileges under the Indenture as
the holder of the Subordinated Debt Securities. In addition, the Property
Trustee will maintain exclusive control of a segregated non-interest bearing
bank account (the "Property Account") to hold all payments made in respect of
the Subordinated Debt Securities for the benefit of the holders of the Trust
Securities. The Property Trustee will make payments of distributions and
payments on liquidation, redemption and otherwise to the holders of the Trust
Securities out of funds from the Property Account. The Guarantee Trustee will
hold the Guarantee for the benefit of the holders of the Preferred Securities.
The Company, as the holder of all the Common Securities, will have the right to
appoint, remove or replace any Regular Trustee and to increase or decrease the
number of the Regular Trustees; provided that, (i) the number of Regular
Trustees will be at least three, and (ii) a majority will be persons who are
employees or officers of, or who are affiliated with, the Company. The Company
will pay all debts and obligations of the Trust (other than with respect to
Trust Securities), including all fees and expenses related to the Trust and the
offering of the Trust Securities. See "Description of the Subordinated Debt
Securities -- Miscellaneous."

         The rights of the holders of the Preferred Securities, including
economic rights, rights to information and voting rights, are set forth in the
Declaration, the Delaware Business Trust Act (the "Trust Act") and the Trust
Indenture Act. See "Description of the Preferred Securities."

                              ACCOUNTING TREATMENT

   
         The financial statements of the Trust will be reflected in the
Company's consolidated financial statements, with the Preferred Securities
shown as a separate item below total liabilities, and above stockholders'
equity, under the caption "Company-Obligated Mandatorily Redeemable Preferred
Securities of Southwest Gas Capital I" on the Company's consolidated statements
of financial condition and as a separate item before net income (loss) under
the caption "Payments on Company-Obligated Mandatorily Redeemable Preferred
Securities of Southwest Gas Capital I" on the Company's consolidated statements
of income.
    

   
         It will be disclosed in a footnote to the consolidated statements of
financial position of the Company that all of the assets of the Trust will be
approximately $______ million of Subordinated Debt Securities of the Company
which will bear interest at a rate of ___% per annum, assuming the issuance of
____ million of Preferred Securities. It will also be disclosed in a footnote
to the Company's consolidated financial statements that (i) the Trust is
wholly owned, (ii) the obligations of the Company under the Declaration, the
Guarantee, the Indenture and the Subordinated Debt Securities collectively
provide a full and unconditional guarantee on a subordinated basis by the
Company of payments due on the Preferred Securities, to the extent the Trust
has funds available therefor as a result of payments of interest or principal
on the Subordinated Debt Securities by the Company. In addition, the disclosure
on the Company's consolidated statements of financial condition will be
repeated.
    

                                      S-13


<PAGE>   14




                                 USE OF PROCEEDS

         All of the proceeds from the sale of the Preferred Securities will be
invested by the Trust in Subordinated Debt Securities of the Company issued
pursuant to the Indenture and ultimately will be used by the Company for
___________________________________.

                     DESCRIPTION OF THE PREFERRED SECURITIES

         The Preferred Securities will be issued pursuant to the terms of the
Declaration. The Declaration will be qualified as an indenture under the Trust
Indenture Act. The Property Trustee, Harris Trust and Savings Bank, will act as
indenture trustee under the Declaration for purposes of compliance with the
provisions of the Trust Indenture Act. The terms of the Preferred Securities
will include those stated in the Declaration and those made part of the
Declaration by the Trust Indenture Act. The following summary of the principal
terms and provisions of the Preferred Securities does not purport to be complete
and is subject to, and qualified in its entirety by reference to, the
Declaration, a copy of which is filed as an exhibit to the Registration
Statement of which this Prospectus Supplement is a part, the Trust Act and the
Trust Indenture Act.

GENERAL

         The Declaration authorizes the Regular Trustees to issue on behalf of
the Trust the Trust Securities, which represent undivided beneficial interests
in the assets of the Trust. All of the Common Securities will be owned, directly
or indirectly, by the Company. The Common Securities rank pari passu, and
payments will be made thereon on a pro rata basis, with the Preferred
Securities, except that upon the occurrence of a Declaration Event of Default
(as defined herein) the rights of the holders of the Common Securities to
receive payment of periodic distributions and payments upon liquidation,
redemption and otherwise will be subordinated to the rights of the holders of
the Preferred Securities. The Declaration does not permit the issuance by the
Trust of any securities other than the Trust Securities or the incurrence of any
indebtedness by the Trust. Pursuant to the Declaration, the Property Trustee
will own the Subordinated Debt Securities purchased by the Trust for the benefit
of the holders of the Trust Securities. The payment of distributions out of
money held by the Trust, and payments upon redemption of the Preferred
Securities or liquidation of the Trust, are guaranteed by the Company to the
extent described under "Description of the Guarantee" in the accompanying
Prospectus. The Guarantee will be held by Harris Trust and Savings Bank, the
Guarantee Trustee, for the benefit of the holders of the Preferred Securities.
The Guarantee does not cover payment of distributions when the Trust does not
have sufficient available funds to pay such distributions. In such event, the
remedy of a holder of Preferred Securities is to direct the Property Trustee to
enforce the Property Trustee's rights under the Subordinated Debt Securities
and, if the Property Trustee fails to enforce such rights, to institute a suit
directly against the Company to enforce the Property Trustee's rights. See
"Description of the Preferred Securities -- Voting Rights."

                                      S-14


<PAGE>   15



DISTRIBUTIONS

         Distributions on the Preferred Securities will be fixed at a rate per
annum of ____% of the stated liquidation amount of $25 per Preferred Security.
Distributions in arrears for more than one quarter will bear interest thereon at
the rate per annum of _____% thereof compounded quarterly. The term
"distribution" as used herein includes any such interest payable, unless
otherwise stated. The amount of distributions payable for any period will be
computed on the basis of a 360-day year of twelve 30-day months.

         Distributions on the Preferred Securities will be cumulative, will
accrue from ______, ___, and will be payable quarterly in arrears on March 31,
June 30, September 30 and December 31 of each year, commencing ________, ____.
When, as and if available for payment, distributions will be made by the
Property Trustee, except as otherwise described below.

         The Company has the right under the Indenture to defer payments of
interest on the Subordinated Debt Securities by extending the interest payment
period from time to time on the Subordinated Debt Securities, which, if
exercised, would defer quarterly distributions on the Preferred Securities
(though such distributions would continue to accrue with interest since interest
would continue to accrue on the Subordinated Debt Securities) during any such
Extension Period. Such right to extend the interest payment period for the
Subordinated Debt Securities is limited to a period not exceeding 20 consecutive
quarters. In the event that the Company exercises this right, then (i) the
Company shall not declare or pay dividends on, make distributions with respect
to, or redeem, purchase or acquire, or make a liquidation payment with respect
to, any of its capital stock and (ii) the Company shall not make any payment of
interest, principal or premium, if any, on or repay, repurchase or redeem any
debt securities issued by the Company that rank pari passu with or junior to
such Subordinated Debt Securities; provided, however, that, the foregoing
restriction (i) does not apply to any stock dividends paid by the Company where
the dividend stock is the same stock as that on which the dividend is being
paid. Prior to the termination of any such Extension Period, the Company may
further extend the interest payment period; provided that, such Extension
Period, together with all such previous and further extensions within such
Extension Period, may not exceed 20 consecutive quarters. Upon the termination
of any Extension Period and the payment of all amounts then due, the Company may
select a new Extension Period, subject to the above requirements. See
"Description of the Subordinated Debt Securities -- Interest" and " -- Option to
Extend Interest Payment Period." If distributions are deferred, the deferred
distributions and accrued interest thereon will be paid to holders of record of
the Preferred Securities as they appear on the books and records of the Trust on
the record date next following the termination of such deferral period.

         Distributions on the Preferred Securities must be paid on the dates
payable to the extent that the Trust has funds available for the payment of such
distributions in the Property Account. The Trust's funds available for
distribution to the holders of the Preferred Securities will be limited to
payments received from the Company on the Subordinated Debt Securities. See
"Description of the Subordinated Debt Securities." The payment of

                                      S-15


<PAGE>   16



distributions out of moneys held by the Trust is guaranteed by the Company to
the extent set forth under "Description of the Guarantee" in the accompanying
Prospectus.

         Distributions on the Preferred Securities will be payable to the
holders thereof as they appear on the books and records of the Trust on the
relevant record dates, which, as long as the Preferred Securities remain in
book-entry only form, will be one Business Day prior to the relevant payment
dates. Such distributions will be paid through the Property Trustee who will
hold amounts received in respect of the Subordinated Debt Securities in the
Property Account for the benefit of the holders of the Trust Securities. Subject
to any applicable laws and regulations and the provisions of the Declaration,
each such payment will be made as described under "Book-Entry Only Issuance --
The Depository Trust Company" below. In the event that the Preferred Securities
do not continue to remain in book-entry only form, the Regular Trustees will
have the right to select relevant record dates, which must be more than one
Business Day prior to the relevant payment dates. In the event that any date on
which distributions are to be made on the Preferred Securities is not a Business
Day, then payment of the distributions payable on such date will be made on the
next succeeding day which is a Business Day (and without any interest or other
payment in respect of any such delay), except that, if such Business Day is in
the next succeeding calendar year, such payment will be made on the immediately
preceding Business Day, in each case with the same force and effect as if made
on such record date. A "Business Day" means any day other than Saturday, Sunday
or any other day on which banking institutions in New York, New York, Chicago,
Illinois or Los Angeles, California are permitted or required by any applicable
law to close.

MANDATORY REDEMPTION

        The Subordinated Debt Securities will mature on ______, ____ [30 years
after issuance of the Subordinated Debt Securities], unless the maturity date
is extended at the option of the Company (provided certain financial conditions
are met), and may be redeemed, in whole or in part, at any time on or after
______, ____ [five years after issuance of the Subordinated Debt Securities],
or at any time in certain circumstances upon the occurrence of a Tax Event.
Upon the repayment of the Subordinated Debt Securities, whether at maturity or
upon redemption, the proceeds from such repayment or payment will
simultaneously be applied to redeem Trust Securities having an aggregate
liquidation amount equal to the aggregate principal amount of the Subordinated
Debt Securities so repaid or redeemed at the Redemption Price; provided that,
holders of Trust Securities are given not less than 30 nor more than 60 days
notice of such redemption. See "Description of the Subordinated Debt Securities
- -- Optional Redemption." In the event that fewer than all of the outstanding
Preferred Securities are to be redeemed, the Preferred Securities will be
redeemed pro rata as described under "Book-Entry Only Issuance - - The
Depository Trust Company" below.

TAX EVENT REDEMPTION OR DISTRIBUTION

                                      S-16


<PAGE>   17



         "Tax Event" means the receipt by, and upon the request of, the Regular
Trustees of an opinion of nationally recognized independent tax counsel
experienced in such matters (a "Dissolution Tax Opinion") to the effect that, as
a result of (i) any amendment to, or change (including any announced prospective
change) in, the laws (or any regulations thereunder) of the United States or any
political subdivision or taxing authority thereof or therein, (ii) any amendment
to or change in an interpretation or application of such laws or regulations by
any legislative body, court, governmental agency or regulatory authority
(including the enactment of any legislation and the publication of any judicial
decision or regulatory determination on or after the date of this Prospectus
Supplement), (iii) any interpretation or pronouncement by any such body, court,
agency or authority that provides for a position with respect to such laws or
regulations that differs from the theretofore generally accepted position or
(iv) any action taken by any governmental agency or regulatory authority, which
amendment or change is enacted, promulgated or effective, or which
interpretation or pronouncement is issued or announced, or which action is
taken, in each case on or after the date of this Prospectus Supplement, there is
more than an insubstantial risk that (a) the Trust is, or within 90 days of the
date thereof will be, subject to United States federal income tax with respect
to income accrued or received on the Subordinated Debt Securities, (b) interest
payable to the Trust on the Subordinated Debt Securities is, or within 90 days
of the date thereof, will not be deductible, by the Company for United States
federal income tax purposes or (c) the Trust is, or within 90 days of the date
thereof will be, subject to more than a de minimis amount of other taxes, duties
or other governmental charges.

         If, at any time, a Tax Event occurs and is continuing, the Trust will,
except in the limited circumstances described below, be dissolved with the
result that the Subordinated Debt Securities with an aggregate principal amount
equal to the aggregate stated liquidation amount of the Trust Securities, will
be distributed to the holders of the Trust Securities in liquidation of such
holders' interests in the Trust on a pro rata basis within 90 days following the
occurrence of such Tax Event; provided, however, that such dissolution and
distribution will be conditioned on (i) the Regular Trustees receipt of an
opinion of nationally recognized independent tax counsel experienced in such
matters (a "No Recognition Opinion"), which opinion may rely on published
revenue rulings of the Internal Revenue Service, to the effect that the holders
of the Trust Securities will not recognize any gain or loss for United States
federal income tax purposes as a result of such dissolution and distribution of
Subordinated Debt Securities and (ii) the inability of the Company and the Trust
to avoid such Tax Event within such 90-day period by taking some ministerial
action or pursuing some other reasonable measure that will have no adverse
effect on the Trust, the Company or the holders of the Trust Securities.
Furthermore, if, after receipt of a Dissolution Tax Opinion by and upon the
request of the Regular Trustees, (i) the Company has received an opinion of
nationally recognized independent tax counsel experienced in such matters (a
"Redemption Tax Opinion") to the effect that, as a result of a Tax Event, there
is more than an insubstantial risk that the Company would be precluded from
deducting the interest on the Subordinated Debt Securities for United States
federal income tax purposes even after the Subordinated Debt Securities were
distributed to the holders of Trust Securities in liquidation of such holders'
interests in the Trust, as described above, or (ii) the Regular Trustees have
been informed by such tax counsel that it cannot deliver a No Recognition
Opinion to the

                                      S-17


<PAGE>   18



Trust, the Company will have the right, upon not less than 30 nor more than 60
days notice, to redeem the Subordinated Debt Securities, in whole or in part,
for cash within 90 days following the occurrence of such Tax Event and,
following such redemption, Trust Securities with an aggregate liquidation amount
equal to the aggregate principal amount of the Subordinated Debt Securities so
redeemed will be redeemed by the Trust at the Redemption Price on a pro rata
basis; provided, however, that, if at the time there is available to the Company
or the Trust the opportunity to avoid, within such 90-day period, the Tax Event
by taking some ministerial action, such as filing a form or making an election
or pursuing some other similar reasonable measure that has no adverse effect on
the Trust, the Company or the holders of the Trust Securities, the Company or
the Trust will pursue such measure in lieu of redemption.

         If the Subordinated Debt Securities are distributed to the holders of
the Preferred Securities, the Company will use its best efforts to cause the
Subordinated Debt Securities to be listed on the New York Stock Exchange or on
such other exchange as the Preferred Securities are then listed.

         After the date for any distribution of Subordinated Debt Securities
upon dissolution of the Trust, (i) the Preferred Securities will no longer be
deemed to be outstanding, (ii) the Depositary (as defined herein) or its
nominee, as the record holder of the Preferred Securities, will receive a
registered global certificate or certificates representing the Subordinated Debt
Securities to be delivered upon such distribution, and (iii) any certificates
representing Preferred Securities not held by the Depositary or its nominee will
be deemed to represent Subordinated Debt Securities having an aggregate
principal amount equal to the aggregate stated liquidation amount of such
Preferred Securities until such certificates are presented to the Company or its
agent for transfer or reissuance.

         There can be no assurance as to the market prices for either the
Preferred Securities or the Subordinated Debt Securities that may be distributed
in exchange for the Preferred Securities if a dissolution and liquidation of the
Trust were to occur. Accordingly, the Preferred Securities that an investor may
purchase, whether pursuant to the offer made hereby or in the secondary market,
or the Subordinated Debt Securities that an investor may receive if a
dissolution and liquidation of the Trust were to occur, may trade at a discount
to the price that the investor paid to purchase the Preferred Securities offered
hereby.

REDEMPTION PROCEDURES

         The Trust may not redeem fewer than all of the outstanding Preferred
Securities unless all accrued and unpaid distributions have been paid on all
Preferred Securities for all quarterly distribution periods terminating on or
prior to the date of redemption.

         If the Trust gives a notice of redemption in respect of Preferred
Securities (which notice will be irrevocable), then, by 12:00 noon, New York
City time, on the redemption date, provided the Company has paid to the Property
Trustee a sufficient amount of cash in connection with the related redemption or
maturity of the Subordinated Debt Securities, then

                                      S-18


<PAGE>   19



the Trust will irrevocably deposit with the Depositary funds sufficient to pay
the applicable Redemption Price and will give the Depositary irrevocable
instructions and authority to pay the Redemption Price to the holders of the
Preferred Securities. See "Book-Entry Only Issuance -- The Depository Trust
Company." If notice of redemption has been given and funds deposited as
required, then, immediately prior to the close of business on the date of such
deposit, distributions will cease to accrue and all rights of holders of such
Preferred Securities so called for redemption will cease, except the right of
the holders of such Preferred Securities to receive the Redemption Price but
without interest on such Redemption Price. In the event that any date fixed for
redemption of Preferred Securities is not a Business Day, then payment of the
Redemption Price payable on such date will be made on the next succeeding day
that is a Business Day (without any interest or other payment in respect of any
such delay), except that, if such Business Day falls in the next calendar year,
such payment will be made on the immediately preceding Business Day. In the
event that payment of the Redemption Price in respect of Preferred Securities is
improperly withheld or refused and not paid either by the Trust, or by the
Company pursuant to the Guarantee, distributions on such Preferred Securities
will continue to accrue at the then applicable rate from the original redemption
date to the date of payment, in which case the actual payment date will be
considered the date fixed for redemption for purposes of calculating the
Redemption Price.

         In the event that fewer than all of the outstanding Preferred
Securities are to be redeemed, the Preferred Securities will be redeemed pro
rata as described below under "Book-Entry Only Issuance -- The Depository Trust
Company."

         Subject to the foregoing and applicable law (including, without
limitation, United States federal securities laws), the Company or its
subsidiaries may at any time, and from time to time, purchase outstanding
Preferred Securities by tender, in the open market or by private agreement.

LIQUIDATION DISTRIBUTION UPON DISSOLUTION

         In the event of any voluntary or involuntary liquidation, dissolution,
winding-up or termination of the Trust (each, a "Liquidation"), the then holders
of the Preferred Securities will be entitled to receive out of the assets of the
Trust, after satisfaction of liabilities to creditors of the Trust,
distributions in an amount equal to the aggregate of the stated liquidation
amount of $25 per Preferred Security plus accrued and unpaid distributions
thereon to the date of payment (the "Liquidation Distribution"), unless, in
connection with such Liquidation, Subordinated Debt Securities in an aggregate
stated principal amount equal to the aggregate stated liquidation amount of the
Preferred Securities have been distributed on a pro rata basis to the holders of
the Preferred Securities in exchange for such Preferred Securities. The holders
of the Common Securities will be entitled to receive distributions upon any such
dissolution pro rata with the holders of the Preferred Securities.

         If, upon any such Liquidation, the Liquidation Distribution can be paid
only in part because the Trust has insufficient assets available to pay in full
the aggregate Liquidation

                                      S-19


<PAGE>   20



Distribution, then the amounts payable directly by the Trust on the Preferred
Securities must be paid on a pro rata basis. If a Declaration Event of Default
has occurred and is continuing, the Preferred Securities shall have a preference
over the Common Securities with regard to such distributions.

        Pursuant to the Declaration, the Trust will terminate (i) on ______,
____ [55 years after issuance of the Subordinated Debt Securities], the
expiration of the term of the Trust, (ii) upon the bankruptcy of the Company or
the holder of the Common Securities, (iii) upon the filing of a certificate of
dissolution or its equivalent with respect to the holder of the Common
Securities or the Company, the filing of a certificate of cancellation with
respect to the Trust, or the revocation of the charter of the holder of the
Common Securities or the Company and the expiration of 90 days after the date
of revocation without a reinstatement thereof, (iv) upon the distribution of
Subordinated Debt Securities upon the occurrence of a Tax Event, (v) upon the
entry of a decree of a judicial dissolution of the holder of the Common
Securities, the Company or the Trust, or (vi) upon the redemption of all the
Trust Securities.

DECLARATION EVENTS OF DEFAULT

         An event of default under the Indenture (an "Indenture Event of
Default") constitutes an event of default under the Declaration with respect to
the Trust Securities (a "Declaration Event of Default"), provided that, pursuant
to the Declaration, the holder of the Common Securities will be deemed to have
waived any Declaration Event of Default with respect to the Common Securities
until all Declaration Events of Default with respect to the Preferred Securities
have been cured, waived or otherwise eliminated. Until such Declaration Events
of Default with respect to the Preferred Securities have been so cured, waived,
or otherwise eliminated, the Property Trustee will be deemed to be acting solely
on behalf of the holders of the Preferred Securities and only the holders of the
Preferred Securities will have the right to direct the Property Trustee with
respect to certain matters under the Declaration, and therefore the Indenture.

         Upon the occurrence of a Declaration Event of Default, the Property
Trustee as the sole holder of the Subordinated Debt Securities will have the
right under the Indenture to declare the principal of and interest on the
Subordinated Debt Securities to be immediately due and payable. The Company and
the Trust are each required to file annually with the Property Trustee an
officer's certificate as to its compliance with all conditions and covenants
under the Declaration.

VOTING RIGHTS

         Except as described herein, under the Trust Act, the Trust Indenture
Act and under "Description of the Guarantee" in the accompanying Prospectus, and
as otherwise required by law and the Declaration, the holders of the Preferred
Securities will have no voting rights.

                                      S-20


<PAGE>   21



   
         Subject to the requirement of the Property Trustee obtaining a tax
opinion in certain circumstances set forth in the last sentence of this
paragraph, the holders of a majority in aggregate liquidation amount of the
Preferred Securities, have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Property Trustee, or
direct the exercise of any trust or power conferred upon the Property Trustee
under the Declaration including the right to direct the Property Trustee, as
holder of the Subordinated Debt Securities, to (i) exercise the remedies
available under the Indenture with respect to the Subordinated Debt Securities,
(ii) waive any past Indenture Event of Default that is waivable under Section
513 of the Base Indenture (as defined herein), or (iii) exercise any right to
rescind or annul a declaration that the principal of all the Subordinated Debt
Securities shall be due and payable; provided, however, that, where a consent or
action under the Indenture would require the consent or act of all of the
holders of the Subordinated Debt Securities, all of the holders of the Preferred
Securities may direct the Property Trustee to give such consent or take such
action. If the Property Trustee fails to enforce its rights under the
Subordinated Debt Securities, a record holder of Preferred Securities may
institute a legal proceeding directly against the Company to enforce the
Property Trustee's rights under the Subordinated Debt Securities without first
instituting any legal proceeding against the Property Trustee or any other
person or entity. The Property Trustee must notify all holders of the Preferred
Securities of any notice of default received from the Indenture Trustee with
respect to the Subordinated Debt Securities. Such notice will state that such
Indenture Event of Default also constitutes a Declaration Event of Default.
Except with respect to directing the time, method and place of conducting a
proceeding for a remedy, the Property Trustee will not take any of the actions
described in clauses (i), (ii) or (iii) above unless the Property Trustee has
obtained an opinion of tax counsel to the effect that, as a result of such
action, the Trust will not fail to be classified as a grantor trust for United
States federal income tax purposes.
    

         In the event the consent of the Property Trustee, as the holder of the
Subordinated Debt Securities, is required under the Indenture with respect to
any amendment, modification or termination of the Indenture, the Property
Trustee will request the direction of the holders of the Trust Securities with
respect to such amendment, modification or termination and will vote with
respect to such amendment, modification or termination as directed by a majority
in liquidation amount of the Trust Securities voting together as a single class;
provided, however, that where a consent under the Indenture would require the
consent of all of the holders of the Subordinated Debt Securities, the Property
Trustee may only give such consent at the direction of the holders of all of the
Trust Securities. The Property Trustee will be under no obligation to take any
such action in accordance with the directions of the holders of the Trust
Securities unless the Property Trustee has obtained an opinion of tax counsel to
the effect that for the purposes of United States federal income tax the Trust
will not be classified as other than a grantor trust.

         A waiver of an Indenture Event of Default will constitute a waiver of
the corresponding Declaration Event of Default.

                                      S-21


<PAGE>   22



         Any required approval or direction of holders of Preferred Securities
may be given at a separate meeting of holders of Preferred Securities convened
for such purpose, at a meeting of all of the holders of Trust Securities or
pursuant to written consent. The Regular Trustees will cause a notice of any
meeting at which holders of Preferred Securities are entitled to vote, or of any
matter upon which action by written consent of such holders is to be taken, to
be mailed to each holder of record of Preferred Securities. Each such notice
will include a statement setting forth the following information: (i) the date
of such meeting or the date by which such action is to be taken, (ii) a
description of any resolution proposed for adoption at such meeting on which
such holders are entitled to vote or of such matter upon which written consent
is sought, and (iii) instructions for the delivery of proxies or consents. No
vote or consent of the holders of Preferred Securities will be required for the
Trust to redeem and cancel Preferred Securities or distribute Subordinated Debt
Securities in accordance with the Declaration.

         Notwithstanding that holders of Preferred Securities are entitled to
vote or consent under any of the circumstances described above, any of the
Preferred Securities that are owned at such time by the Company or any entity
directly or indirectly controlling or controlled by, or under direct or indirect
common control with, the Company, will not be entitled to vote or consent and
will, for purposes of such vote or consent, be treated as if such Preferred
Securities were not outstanding.

         The procedures by which holders of Preferred Securities may exercise
their voting rights are described below. See "-- Book-Entry Only Issuance - The
Depository Trust Company" below.

         Holders of the Preferred Securities will have no rights to appoint or
remove the Regular Trustees, who may be appointed, removed or replaced solely by
the Company as the holder of all of the Common Securities.

MODIFICATION OF THE DECLARATION

         The Declaration may be modified and amended if approved by a majority
of the Regular Trustees (and in certain circumstances the Property Trustee),
provided that, if any proposed amendment provides for, or the Regular Trustees
otherwise propose to effect, (i) any action that would adversely affect the
powers, preferences or special rights of the Trust Securities, whether by way of
amendment to the Declaration or otherwise, or (ii) the dissolution, winding-up
or termination of the Trust other than pursuant to the terms of the Declaration,
then the holders of the Trust Securities voting together as a single class will
be entitled to vote on such amendment or proposal and such amendment or proposal
will not be effective except with the approval of at least 66 2/3% in
liquidation amount of the Trust Securities affected thereby; provided that if
any amendment or proposal referred to in clause (i) above would adversely affect
only the Preferred Securities or the Common Securities, then only the affected
class will be entitled to vote on such amendment or proposal and such amendment
or proposal will not be effective except with the approval of 66 2/3% in
liquidation amount of such class of Trust Securities.

                                      S-22
<PAGE>   23
         Notwithstanding the foregoing, no amendment or modification may be
made to the Declaration if such amendment or modification would (i) cause the
Trust to be classified for purposes of United States federal income taxation as
other than a grantor trust, (ii) reduce or otherwise adversely affect the
powers of the Property Trustee or (iii) cause the Trust to be deemed an
"investment company" which is required to be registered under the Investment
Company Act of 1940, as amended (the "1940 Act").

MERGERS, CONSOLIDATIONS OR AMALGAMATIONS

         The Trust may not consolidate, amalgamate, merge or be replaced by, or
convey, transfer or lease its properties and assets substantially as an
entirety, to any corporation or other body, except as described below.  The
Trust may, with the consent of a majority of the Regular Trustees and without
the consent of the holders of the Trust Securities, consolidate, amalgamate,
merge with or into, or be replaced by a trust organized as such under the laws
of any State; provided that, (i) such successor entity either (a) expressly
assumes all of the obligations of the Trust under the Trust Securities or (b)
substitutes for the Preferred Securities other securities having substantially
the same terms as the Trust Securities (the "Successor Securities"), so long as
the Successor Securities rank the same as the Trust Securities with respect to
distributions and  payments upon liquidation, redemption and otherwise, (ii)
the Company expressly acknowledges a trustee of such successor entity
possessing the same powers and duties of the Property Trustee as the holder of
the Subordinated Debt Securities, (iii) the Preferred Securities or any
Successor Securities are listed, or any Successor Securities will be listed
upon notification of issuance, on any national securities exchange or with
another organization on which the Preferred Securities are then listed or
quoted, (iv) such merger, consolidation, amalgamation or replacement does not
cause the Preferred Securities (including any Successor Securities) to be
downgraded by any nationally recognized statistical rating organization, (v)
such merger, consolidation, amalgamation or replacement does not adversely
affect the rights, preferences and privileges of the holders of the Trust
Securities (including any Successor Securities) in any material respect, (vi)
such successor entity has a purpose identical to that of the Trust, (vii) prior
to such merger, consolidation, amalgamation or replacement, the Company has
received an opinion of a nationally recognized independent counsel to the Trust
experienced in such matters to the effect that, (a) such merger, consolidation,
amalgamation or replacement does not adversely affect the rights, preferences
and privileges of the holders of the Trust Securities (including any Successor
Securities) in any material respect, and (b) following such merger,
consolidation, amalgamation or replacement, neither the Trust nor such
successor entity will be required to register as an investment company under
the 1940 Act and (viii) the Company guarantees the obligations of such
successor entity under the Successor Securities at least to the extent provided
by the Guarantee and the Common Securities Guarantee.  Notwithstanding the
foregoing, the Trust may not, except with the consent of holders of 100% in
liquidation amount of the Trust Securities, consolidate, amalgamate, merge with
or into, or be replaced by any other entity or permit any other entity to
consolidate, amalgamate, merge with or into, or replace it, if such
consolidation, amalgamation, merger or replacement would cause the Trust or
such successor entity to be classified as other than a grantor trust for United
States federal income tax purposes.





                                      S-23
<PAGE>   24

         There are no provisions which afford the holders of the Preferred
Securities protection in the event of a highly leveraged transaction,
reorganization, restructuring, merger or similar transaction involving the
Company.  There are also no provisions which require the repurchase of the
Preferred Securities upon a change in control of the Company.

BOOK-ENTRY ONLY ISSUANCE -- THE DEPOSITORY TRUST COMPANY

         The Depository Trust Company (the "Depositary") will act as securities
depository for the Preferred Securities.  The Preferred Securities will be
issued only as fully-registered securities registered in the name of Cede & Co.
(the Depositary's nominee).  One or more fully-registered global Preferred
Securities certificates, representing the total aggregate number of Preferred
Securities, will be issued and will be deposited with the Depositary.

         The laws of some jurisdictions require that certain purchasers of
securities take physical delivery of securities in definitive form.  Such laws
may impair the ability to transfer beneficial interests in the global Preferred
Securities as represented by a global certificate.

         The Depositary is a limited-purpose trust company organized under the
New York Banking Law, a "banking organization" within the meaning of the New
York Banking Law, a member of the Federal Reserve System, a "clearing
corporation" within the meaning of the New York Uniform Commercial Code, and a
"clearing agency" registered pursuant to the provisions of Section 17A of the
Securities Exchange Act of 1934, as amended (the "Exchange Act").  The
Depositary holds securities that its participants ("Participants") deposit with
the Depositary.  The Depositary also facilitates the settlement among
Participants of securities transactions, such as transfers and pledges, in
deposited securities through electronic computerized book-entry changes in
Participants' accounts, thereby eliminating the need for physical movement of
securities certificates.  Direct Participants include securities brokers and
dealers, banks, trust companies, clearing corporations and certain other
organizations ("Direct Participants").  The Depositary is owned by a number of
its Direct Participants and by the New York Stock Exchange, Inc. (the "New York
Stock Exchange"), the American Stock Exchange, Inc., and the National
Association of Securities Dealers, Inc.  Access to the depository system is
also available to others, such as securities brokers and dealers, banks and
trust companies that clear transactions through or maintain a direct or
indirect custodial relationship with a Direct Participant, either directly or
indirectly ("Indirect Participants").  The rules applicable to the Depositary
and its Participants are on file with the Commission.

         Purchases of Preferred Securities within the depository system must be
made by or through Direct Participants, which will receive a credit for the
Preferred Securities on the Depositary's records.  The ownership interest of
each actual purchaser of each Preferred Security ("Beneficial Owner") is in
turn to be recorded on the Direct and Indirect Participants' records.
Beneficial Owners will not receive written confirmation from the Depositary of
their purchases, but Beneficial Owners are expected to receive written
confirmations providing details of the transactions, as well as periodic
statements of their





                                      S-24
<PAGE>   25
holdings, from the Direct or Indirect Participants through which the Beneficial
Owners purchased Preferred Securities.  Transfers of ownership interests in the
Preferred Securities are to be accomplished by entries made on the books of
Participants acting on behalf of Beneficial Owners.  Beneficial Owners will not
receive certificates representing their ownership interests in the Preferred
Securities, except in the event that use of the book-entry system for the
Preferred Securities is discontinued.

         To facilitate subsequent transfers, all the Preferred Securities
deposited by Participants with the Depositary are registered in the name of the
Depositary's nominee, Cede & Co.  The deposit of Preferred Securities with the
Depositary and their registration in the name of Cede & Co. effect no change in
beneficial ownership.  The Depositary has no knowledge of the actual Beneficial
Owners of the Preferred Securities.  The Depositary's records reflect only the
identity of the Direct Participants to whose accounts such Preferred Securities
are credited, which may or may not be the Beneficial Owners.  The Participants
will remain responsible for keeping account of their holdings on behalf of
their customers.

         Conveyance of notices and other communications by the Depositary to
Direct Participants, by Direct Participants to Indirect Participants and by
Direct Participants and Indirect Participants to Beneficial Owners will be
governed by arrangements among them, subject to any statutory or regulatory
requirements that may be in effect from time to time.

         Redemption notices will be sent to Cede & Co.  If less than all of the
Preferred Securities are being redeemed, the Depositary will reduce the amount
of the interest of each Direct Participant in such Preferred Securities in
accordance with its procedures.

         Although voting with respect to the Preferred Securities is limited,
in those cases where a vote is required, neither the Depositary nor Cede & Co.
will itself consent or vote with respect to Preferred Securities.  Under its
usual procedures, the Depositary would mail an Omnibus Proxy to the Trust as
soon as possible after the record date.  The Omnibus Proxy assigns Cede & Co.
consenting or voting rights to those Direct Participants to whose accounts the
Preferred Securities are credited on the record date (identified in a listing
attached to the Omnibus Proxy).  The Company and the Trust believe that the
arrangements among the Depositary, Direct and Indirect Participants and
Beneficial Owners will enable the Beneficial Owners to exercise rights
equivalent in substance to the rights that can be directly exercised by a
holder of a beneficial interest in the Trust.

         Distribution payments on the Preferred Securities will be made to the
Depositary.  The Depositary's practice is to credit Direct Participants'
accounts on the relevant payment date in accordance with their respective
holdings shown on the Depositary's records unless the Depositary has reason to
believe that it will not receive payments on such payment date.  Payments by
Participants to Beneficial Owners will be governed by standing instructions and
customary practices, as is the case with securities held for the account of
customers in bearer form or registered in "street name," and such payments will
be the responsibility of such Participants and not of the Depositary, the Trust
or the Company, subject to any statutory or regulatory requirements to the
contrary that may be in effect from time to time.  Payment of





                                      S-25
<PAGE>   26
distributions to the Depositary is the responsibility of the Trust,
disbursement of such payments to Direct Participants is the responsibility of
the Depositary, and disbursement of such payments to the Beneficial Owners is
the responsibility of Direct and Indirect Participants.

         Except as provided herein, a Beneficial Owner in a global Preferred
Security certificate will not be entitled to receive physical delivery of
Preferred Securities.  Accordingly, each Beneficial Owner must rely on the
procedures of the Depositary to exercise any rights under the Preferred
Securities.

         The Depositary may discontinue providing its services as securities
depository with respect to the Preferred Securities at any time by giving
reasonable notice to the Trust.  Under such circumstances, in the event that a
successor securities depository is not obtained, Preferred Securities
certificates are required to be printed and delivered.  Additionally, the
Regular Trustees (with the consent of the Company) may decide to discontinue
use of the system of book-entry transfers through the Depositary (or any
successor depository) with respect to the Preferred Securities.  In that event,
certificates for the Preferred Securities will be printed and delivered.

         The information in this section concerning the Depositary and the
Depositary's book-entry system has been obtained from sources that the Company
and the Trust believe to be reliable, but neither the Company nor the Trust
takes responsibility for the accuracy thereof.

INFORMATION CONCERNING THE PROPERTY TRUSTEE

         The Property Trustee, prior to the occurrence of a default with
respect to the Trust Securities, undertakes to perform only such duties as are
specifically set forth in the Declaration and, after default, shall exercise
the same degree of care as a prudent individual would exercise in the conduct
of his or her own affairs.  Subject to such provisions, the Property Trustee is
under no obligation to exercise any of the powers vested in it by the
Declaration at the request of any holder of Preferred Securities, unless
offered reasonable indemnity by such holder against the costs, expenses and
liabilities which might be incurred thereby.  The holders of Preferred
Securities will not be required to offer such indemnity in the event such
holders, by exercising their voting rights, direct the Property Trustee to take
any action following a Declaration Event of Default.

PAYING AGENT

         In the event that the Preferred Securities do not remain in book-entry
only form, the following provisions would apply:

         The Property Trustee will act as paying agent, and may designate an
additional or substitute paying agent at any time.





                                      S-26
<PAGE>   27
         Registration of transfers of Preferred Securities will be effected
without charge by or on behalf of the Trust, but upon payment (with the giving
of such indemnity as the Trust or the Company may require) in respect of any
tax or other governmental charges that may be imposed in relation to it.

         The Trust will not be required to register or cause to be registered
the transfer of Preferred Securities after such Preferred Securities have been
called for redemption.


GOVERNING LAW

         The Declaration and the Preferred Securities will be governed by, and
construed in accordance with, the internal laws of the State of Delaware.


MISCELLANEOUS

         The Regular Trustees are authorized and directed to operate the Trust
in such a way so that the Trust will not be (i) required to register as an
"investment company" under the 1940 Act or (ii) characterized as other than a
grantor trust for United States federal income tax purposes.  The Company is
authorized and directed to conduct its affairs so that the Subordinated Debt
Securities will be treated as indebtedness of the Company for United States
federal income tax purposes.  In this connection, the Company and the Regular
Trustees are authorized to take any action, not inconsistent with applicable
law, the certificate of trust of the Trust or the articles of incorporation of
the Company, that each of the Company and the Regular Trustees determines in
its discretion to be necessary or desirable to achieve such end, as long as
such action does not adversely affect the interests of the holders of the
Preferred Securities or vary the terms thereof.

         Holders of the Preferred Securities have no preemptive rights.

                DESCRIPTION OF THE SUBORDINATED DEBT SECURITIES

         Set forth below is a description of the specific terms of the
Subordinated Debt Securities in which the Trust will invest the proceeds from
the issuance and sale of the Trust Securities.  This description supplements
the description of the general terms and provisions of Subordinated Debt
Securities set forth in the accompanying Prospectus under the captions
"Description of Debt Securities" and "Particular Terms of the Subordinated Debt
Securities Issued in Connection with Preferred Securities."  The following
description does not purport to be complete and is subject to, and is qualified
in its entirety by reference to, the description in the accompanying Prospectus
and the Subordinated Debt Securities Indenture, dated as of ______________,
(the "Base Indenture") between the Company and Harris Trust and Savings Bank,
as Trustee (the "Indenture Trustee"), as supplemented by a First Supplemental
Indenture, dated as of ___________, (the Base Indenture, as so supplemented, is
hereinafter referred to as the "Indenture"), the forms of which are filed as
exhibits to the





                                      S-27
<PAGE>   28
Registration Statement of which this Prospectus Supplement and the accompanying
Prospectus form a part.  Certain capitalized terms used herein are defined in
the Indenture.

         Under certain circumstances involving the dissolution of the Trust
following the occurrence of a Tax Event, Subordinated Debt Securities may be
distributed to the holders of the Trust Securities in liquidation of the Trust.
See "Description of the Preferred Securities -- Tax Event Redemption or
Distribution."

         If the Subordinated Debt Securities are distributed to the holders of
the Preferred Securities, the Company will use its best efforts to have the
Subordinated Debt Securities listed on the New York Stock Exchange or on such
other national securities exchange or similar organization on which the
Preferred Securities are then listed or quoted.


GENERAL

         The Subordinated Debt Securities will be issued as unsecured debt
under the Indenture.  The Subordinated Debt Securities will be limited in
aggregate principal amount to approximately $_____________, such amount being
the sum of the aggregate stated liquidation amount of the Preferred Securities
and the capital contributed by the Company in exchange for the Common
Securities (the "Company Payment").

         The Subordinated Debt Securities are not subject to a sinking fund
provision.  The entire principal amount of the Subordinated Debt Securities
will mature and become due and payable, together with any accrued and unpaid
interest thereon including Compound Interest (as defined herein) and Additional
Interest (as defined herein), if any, on ___________, ____ [30 years after
issuance of Subordinated Debt Securities], subject to the election of the
Company to extend the scheduled maturity date of the Subordinated Debt
Securities to a date not later than ____________, ____ [49 years after issuance
of Subordinated Debt Securities], which election is subject to the Company's
satisfying certain financial conditions.  See " -- Option to Extend Maturity
Date."

         If Subordinated Debt Securities are distributed to holders of
Preferred Securities in liquidation of such holders' interests in the Trust,
such Subordinated Debt Securities will initially be issued as a Global Security
(as defined below).  As described herein, under certain limited circumstances,
Subordinated Debt Securities may be issued in certificated form in exchange for
a Global Security.  See "-- Book-Entry and Settlement" below.  In the event
that Subordinated Debt Securities are issued in certificated form, such
Subordinated Debt Securities will be in denominations of $25 and integral
multiples thereof and may be transferred or exchanged at the offices described
below.  Payments on Subordinated Debt Securities issued as a Global Security
will be made to the Depositary, a successor depository or, in the event that no
depository is used, to a Paying Agent for the Subordinated Debt Securities.  In
the event Subordinated Debt Securities are issued in certificated form,
principal and interest will be payable, the transfer of the Subordinated Debt
Securities will be registrable and Subordinated Debt Securities will be
exchangeable for Subordinated Debt





                                      S-28
<PAGE>   29
Securities of other denominations of a like aggregate principal amount at the
corporate trust office of the Indenture Trustee in New York, New York; provided
that, payment of interest may be made at the option of the Company by check
mailed to the address of the persons entitled thereto.

SUBORDINATION

         The Indenture provides that the Subordinated Debt Securities are
subordinated and junior in right of payment to all Senior Indebtedness of the
Company.  No payment of principal (including redemption and sinking fund
payments), premium, if any, or interest on the Subordinated Debt Securities may
be made (i) if any, Senior Indebtedness of the Company is not paid when due,
(ii) any applicable grace period with respect to such default has ended and
such default has not been cured or waived or ceased to exist, or (iii) if the
maturity of any Senior Indebtedness of the Company has been accelerated because
of a default.  Upon any distribution of assets of the Company to creditors upon
any dissolution, winding-up, liquidation or reorganization, whether voluntary
or involuntary, or in bankruptcy, insolvency, receivership or other
proceedings, all principal, premium, if any, and interest due or to become due
on all Senior Indebtedness of the Company must be paid in full before the
holders of Subordinated Debt Securities are entitled to receive or retain any
payment.  Upon satisfaction of all claims of all Senior Indebtedness then
outstanding, the rights of the holders of the Subordinated Debt Securities will
be subrogated to the rights of the holders of Senior Indebtedness of the
Company to receive payments or distributions applicable to Senior Indebtedness
until all amounts owing on the Subordinated Debt Securities are paid in full.

         The term "Senior Indebtedness" means, with respect to the Company,
Debt of the Company, except for (1) any such Debt that is by its terms
subordinated to or pari passu with the Subordinated Debt Securities and (2) any
Debt (including all other debt securities and guarantees in respect of those
debt securities) initially issued to any other trust, or a trustee of such
trust, partnership, or other entity affiliated with the Company that is,
directly or indirectly, a financing vehicle of the Company in connection with
the issuance by such entity of preferred securities or other similar
securities.  The term "Debt" means, with respect to the Company, (i) the
principal, premium, if any, and interest in respect of (A) indebtedness of the
Company for money borrowed and (B) indebtedness evidenced by securities,
debentures, bonds or other similar instruments issued by the Company, (ii) all
capital lease obligations of the Company, (iii) all obligations of the Company
issued or assumed as the deferred purchase price of property, all conditional
sale obligations of the Company and all obligations of the Company under any
title retention agreement (but excluding trade accounts payable arising in the
ordinary course of business), (iv) all obligations of the Company for the
reimbursement of any letter of credit, banker's acceptance, security purchase
facility or similar credit transaction, (v) all obligations of the type
referred to in clauses (i) through (iv) above of other persons for the payment
of which the Company is responsible or liable as obligor, guarantor or
otherwise, and (vi) all obligations of the type referred to in clauses (i)
through (v) above of other persons secured





                                      S-29
<PAGE>   30
by any lien on any property or asset of the Company (whether or not such
obligation is assumed by the Company).

         The Indenture does not limit the aggregate amount of Senior
Indebtedness that may be issued by the Company.  As of ______________, ____,
Senior Indebtedness of the Company aggregated approximately $__________
million.

OPTIONAL REDEMPTION

         The Company shall have the right to redeem the Subordinated Debt
Securities, in whole or in part, from time to time, on or after ______________,
____ [five years after issuance of Subordinated Debt Securities], or at any
time in certain circumstances upon the occurrence of a Tax Event as described
under "Description of the Preferred Securities -- Tax Event Redemption or
Distribution," upon not less than 30 nor more than 60 days notice, at a
redemption price equal to 100% of the principal amount to be redeemed plus any
accrued and unpaid interest, including Additional Interest, if any, to the
redemption date.  If a partial redemption of the Preferred Securities resulting
from a partial redemption of the Subordinated Debt Securities would result in
the delisting of the Preferred Securities, the Company may only redeem the
Subordinated Debt Securities in whole.

INTEREST

         Each Subordinated Debt Security will bear interest at the rate of ___%
per annum from the original date of issuance, payable quarterly in arrears on
March 31, June 30, September 30 and December 31 of each year (each, an
"Interest Payment Date"), commencing ____________, ____, to the person in whose
name such Subordinated Debt Security is registered, subject to certain
exceptions, at the close of business on the Business Day next preceding such
Interest Payment Date.  In the event the Subordinated Debt Securities do not
remain in book-entry only form, the Company has the right to select record
dates, which must be more than one Business Day prior to the Interest Payment
Date.

         The amount of interest payable for any period will be computed on the
basis of a 360-day year of twelve 30-day months.  The amount of interest
payable for any period shorter than a full quarterly period for which interest
is computed, will be computed on the basis of the actual number of days elapsed
per 30-day month.  In the event that any date on which interest is payable on
the Subordinated Debt Securities is not a Business Day, then payment of the
interest payable on such date will be made on the next succeeding day that is a
Business Day (and without any interest or other payment in respect of any such
delay), except that, if such Business Day is in the next succeeding calendar
year, then such payment shall be made on the immediately preceding Business
Day, in each case with the same force and effect as if made on such date.

OPTION TO EXTEND MATURITY DATE





                                      S-30
<PAGE>   31
         The maturity date of the Subordinated Debt Securities is ___________,
____ [30 years after issuance of the Subordinated Debt Securities] (the "Stated
Maturity Date").  The Company, however, may, before the Stated Maturity Date,
extend such maturity date no more than one time for up to an additional 19
years from the Stated Maturity Date; provided that (i) the Company is not in
bankruptcy or otherwise insolvent, (ii) the Company is not in default on any
Subordinated Debt Securities issued to the Trust or to any other trust or to
any trustee of the Trust or any other trust in connection with an issuance of
Trust Securities by the Trust or any other trust, (iii) the Company has made
timely payments on the Subordinated Debt Securities for the immediately
preceding 18 months without deferrals, (iv) the Trust is not in arrears on
payments of distributions on the Preferred Securities, (v) the Subordinated
Debt Securities are rated in one of the four highest rating categories by any
one of Standard & Poor's Ratings Group, Moody's Investors Service, Inc., Fitch
Investor Services, Duff & Phelps Credit Rating Company or any other nationally
recognized statistical rating organization, and (vi) the final maturity of the
Subordinated Debt Securities is not later than the 49th anniversary of the
issuance of the Preferred Securities.  Pursuant to the Declaration, the Regular
Trustees are required to give notice of the Company's election to extend the
Stated Maturity Date to the holders of the Preferred Securities.

OPTION TO EXTEND INTEREST PAYMENT PERIOD

         The Company has the right at any time, and from time to time, during
the term of the Subordinated Debt Securities to defer payments of interest by
extending the interest payment period for a period not exceeding 20 consecutive
quarters, at the end of which Extension Period, the Company must pay all
interest then accrued and unpaid (including any Additional Interest) together
with interest thereon compounded quarterly at the rate specified for the
Subordinated Debt Securities to the extent permitted by applicable law
("Compound Interest"); provided that, during any such Extension Period, (i) the
Company shall not declare or pay any dividends on, make any distribution with
respect to, or redeem, purchase or acquire or make a liquidation payment with
respect to, any of its capital stock and (ii) the Company shall not make any
payment of interest, principal or premium, if any, on or repay, repurchase or
redeem any debt securities issued by the Company that rank pari passu with or
junior to the Subordinated Debt Securities; provided, however, that, the
foregoing restriction (i) does not apply to any stock dividends paid by the
Company where the dividend stock is the same as that on which the dividend is
paid.

         Prior to the termination of any such Extension Period, the Company may
further defer payments of interest by extending the interest payment period;
provided, however, that, such Extension Period, including all such previous and
further extensions within such Extension Period, may not exceed 20 consecutive
quarters.  Upon the termination of any Extension Period and the payment of all
amounts then due, the Company may commence a new Extension Period, subject to
the terms described in this section.  No interest during an Extension Period,
except at the end thereof, is due and payable.  The Company has no present
intention of exercising its right to defer payments of interest by extending
the interest payment period on the Subordinated Debt Securities.  If the
Property Trustee is the sole holder of the Subordinated Debt Securities, the
Company is required to give the Regular





                                      S-31
<PAGE>   32
Trustees and the Property Trustee notice of its selection of such Extension
Period one Business Day prior to the earlier of (i) the date distributions on
the Preferred Securities are payable or (ii) the date the Regular Trustees are
required to give notice to the New York Stock Exchange (or other applicable
self-regulatory organization) or to holders of the Preferred Securities of the
record date or the date such distribution is payable.  The Regular Trustees
must give notice of the Company's selection of such Extension Period to the
holders of the Preferred Securities.  If the Property Trustee is not the sole
holder of the Subordinated Debt Securities, the Company must give the holders
of the Subordinated Debt Securities notice of its selection of such Extension
Period ten Business Days prior to the earlier of (i) the Interest Payment Date
or (ii) the date on which the Company is required to give notice to the New
York Stock Exchange (or other applicable self-regulatory organization) or to
holders of the Subordinated Debt Securities of the record or payment date of
such related interest payment.

ADDITIONAL INTEREST

         If at any time the Trust is required to pay any taxes, duties,
assessments or governmental charges of whatever nature (other than withholding
taxes) imposed by the United States, or any other taxing authority, then, in
such case, the Company will pay as additional interest on the Subordinated Debt
Securities ("Additional Interest") such additional amounts as shall be required
so that the net amounts received and retained by the Trust after paying such
taxes, duties, assessments or other governmental charges will be not less than
the amounts the Trust would have received had no such taxes, duties,
assessments or other governmental charges been imposed.

EQUAL AND RATABLE SECURITY

         Pursuant to the Indenture, the Company will not create, incur, issue
or assume any Debt secured by any lien on any property or assets owned by the
Company, and the Company will not create, incur, issue or assume any Debt
secured by any lien on any shares of stock of any subsidiary of the Company
(such shares of stock being called "Restricted Securities"), unless (i) in the
case of Debt which is expressly by its terms subordinate or junior in right of
payment to the Subordinated Debt Securities, the Subordinated Debt Securities
are secured by a lien on such property, assets or Restricted Securities that is
senior to such other lien, or (ii) in the case of liens securing Debt that is
ranked pari passu with the Subordinated Debt Securities, the Subordinated Debt
Securities are secured by a lien on such property, assets or Restricted
Securities that is equal and ratable with such other lien; provided, however,
that nothing contained in the Indenture shall apply to or prevent the creation
of:  (1) existing liens on any property or indebtedness of any entity which is
merged with or into or consolidated with the Company; (2) liens in favor of the
United States of America, any state or any foreign country or any department,
agency or instrumentality or political subdivision of any such jurisdiction, to
secure partial, progress, advance or other payment pursuant to any contract or
statute or to secure any indebtedness incurred for the purpose of financing all
or any part of the purchase price or cost of constructing or improving the
property subject to such liens, including, without limitation, liens to secure





                                      S-32
<PAGE>   33
Debt of the pollution control or industrial revenue bond type; (3) liens to
secure loans to the Company which mature within twelve months from the creation
thereof and which are made in the ordinary course of business; (4) liens on any
property (including any natural gas, oil or other mineral property) to secure
all or part of the cost of exploration or drilling for, or development of, oil
or gas reserves or laying a pipeline or to secure Debt incurred to provide
funds for any such purpose; (5)  Liens on moneys or U. S.  Government
Obligations deposited with the Trustee pursuant to the Indenture; and (6) liens
for the sole purposes of extending, renewing or replacing, in whole or in part,
liens securing Debt of the type referred to in the foregoing clauses (1)
through (4) inclusive or this clause (6); provided, however, that the principal
amount of Debt so secured at the time of such extension, renewal or replacement
shall not be increased, and that such extension, renewal or replacement will be
limited to all or part of the property or indebtedness which secured the lien
so extended, renewed or replaced (plus improvements on such property).

INDENTURE EVENTS OF DEFAULT

         If any Indenture Event of Default occurs and is continuing, the
Property Trustee, as the holder of the Subordinated Debt Securities, will have
the right to declare the principal of and the interest on the Subordinated Debt
Securities (including any Compound Interest and Additional Interest, if any)
and any other amounts payable under the Indenture to be forthwith due and
payable and to enforce its other rights as a creditor with respect to the
Subordinated Debt Securities.  See "Description of Debt Securities -- Events of
Default" in the accompanying Prospectus for a description of the Events of
Default.  An Indenture Event of Default also constitutes a Declaration Event of
Default.  The holders of Preferred Securities in certain circumstances have the
right to direct the Property Trustee to exercise its rights as the holder of
the Subordinated Debt Securities.  See "Description of the Preferred Securities
- -- Declaration Events of Default" and "Voting Rights."

BOOK-ENTRY AND SETTLEMENT

         If distributed to holders of Preferred Securities in connection with
the involuntary dissolution, winding-up or liquidation of the Trust as a result
of the occurrence of a Tax Event, the Subordinated Debt Securities will be
issued in the form of one or more global securities registered in the name of
the Depositary or its nominee (each, a "Global Security").  Except under the
limited circumstances described below, Subordinated Debt Securities represented
by the Global Security will not be exchangeable for, and will not otherwise be
issuable as, Subordinated Debt Securities in definitive form.  See " --
Discontinuance of the Depositary's Services".  The Global Securities described
above may not be transferred except by the Depositary to a nominee of the
Depositary or by a nominee of the Depositary to the Depositary or another
nominee of the Depositary or to a successor depositary or its nominee.

         The laws of some jurisdictions require that certain purchasers of
securities take physical delivery of such securities in definitive form.  Such
laws may impair the ability to transfer beneficial interests in such Global
Security.





                                      S-33
<PAGE>   34

         Except as provided below, owners of beneficial interests in such a
Global Security will not be entitled to receive physical delivery of
Subordinated Debt Securities in definitive form and will not be considered the
holders (as defined in the Indenture) thereof for any purpose under the
Indenture, and no Global Security representing Subordinated Debt Securities is
exchangeable, except for another Global Security of like denomination and tenor
to be registered in the name of the Depositary or its nominee or to a successor
Depositary or its nominee.  Accordingly, each Beneficial Owner must rely on the
procedures of the Depositary or if such person is not a Participant, on the
procedures of the Participant through which such person owns its interest to
exercise any rights of a holder under the Indenture.

THE DEPOSITARY

         If Subordinated Debt Securities are distributed to holders of
Preferred Securities in liquidation of such holders' interests in the Trust,
the Depositary will act as securities depositary for the Subordinated Debt
Securities.  For a description of the Depositary and the specific terms of the
depositary arrangements, see "Description of the Preferred Securities --
Book-Entry Only Issuance -- The Depository Trust Company."  As of the date of
this Prospectus Supplement, the description therein of the Depositary's
book-entry system and the Depositary's practices as they relate to purchases,
transfers, notices and payments with respect to the Preferred Securities apply
in all material respects to any debt obligations represented by one or more
Global Securities held by the Depositary.  The Company may appoint a successor
to the Depositary or any successor depository in the event the Depositary or
such successor depository is unable or unwilling to continue as a depository
for the Global Securities.

         None of the Company, the Trust, the Indenture Trustee, any paying
agent and any other agent of the Company or the Indenture Trustee will have any
responsibility or liability for any aspect of the records relating to or
payments made on account of beneficial ownership interests in a Global Security
for such Subordinated Debt Securities or for maintaining, supervising or
reviewing any records relating to such beneficial ownership interests.





                                      S-34
<PAGE>   35

DISCONTINUANCE OF THE DEPOSITARY'S SERVICES

         A Global Security is exchangeable for Subordinated Debt Securities
registered in the names of persons other than the Depositary or its nominee
only if (i) the Depositary notifies the Company that it is unwilling or unable
to continue as a depository for such Global Security and no successor
depository shall have been appointed, (ii) the Depositary at any time, ceases
to be a clearing agency registered under the Exchange Act at which time the
Depositary is required to be so registered to act as such depository and no
successor depository shall have been appointed, (iii) the Company, in its sole
discretion, determines that such Global Security is so exchangeable or (iv)
there shall have occurred an Event of Default with respect to such Subordinated
Debt Securities.  Any Global Security that is exchangeable pursuant to the
preceding sentence is exchangeable for Subordinated Debt Securities registered
in such names as the Depositary shall direct.  It is expected that such
instructions will be based upon directions received by the Depositary from its
Participants with respect to ownership of beneficial interests in such Global
Security.

MISCELLANEOUS

         The Indenture provides that the Company will pay all debts and
obligations of the Trust (other than with respect to Trust Securities),
including all fees and expenses related to (i) the offering of the Trust
Securities and the Subordinated Debt Securities, (ii) the organization,
maintenance and dissolution of the Trust, (iii) the retention of the Regular
Trustees and (iv) the enforcement by the Property Trustee of the rights of the
holders of the Preferred Securities.  The payment of such fees and expenses
will be fully and unconditionally guaranteed by the Company.

                        EFFECT OF OBLIGATIONS UNDER THE
                 SUBORDINATED DEBT SECURITIES AND THE GUARANTEE

         As set forth in the Declaration, the sole purpose of the Trust is to
issue the Trust Securities evidencing undivided beneficial interests in the
assets of the Trust, and to invest the proceeds from such issuance and sale in
the Subordinated Debt Securities.

         As long as payments of interest and other payments are made when due
on the Subordinated Debt Securities, such payments will be sufficient to cover
distributions and payments due on the Trust Securities because of the following
factors:  (i) the aggregate principal amount of Subordinated Debt Securities
will be equal to the sum of the aggregate stated liquidation amount of the
Trust Securities, (ii) the interest rate and the interest and other payment
dates on the Subordinated Debt Securities will match the distribution rate and
distribution and other payment dates for the Preferred Securities, (iii) the
Company is required to pay all, and the Trust is not be obligated to pay,
directly or indirectly, any, costs and expenses of the Trust, and (iv) the
Declaration further provides that the Regular Trustees will not cause or permit
the Trust to, among other things, engage in any activity that is not consistent
with the purposes of the Trust.





                                      S-35
<PAGE>   36

   
         Payments of distributions (to the extent funds therefor are available)
and other payments due on the Preferred Securities (to the extent funds
therefor are available) are guaranteed by the Company as and to the extent set
forth under "Description of the Guarantee" in the accompanying Prospectus.  If
the Company does not make interest payments on the Subordinated Debt Securities
purchased by the Trust, it is expected that the Trust will not have sufficient
funds to pay distributions on the Preferred Securities.  The Guarantee is a
full and unconditional guarantee on a subordinated basis from the time of its 
issuance but does not apply to any payment of distributions unless and until 
the Trust has sufficient funds for the payment of such distributions.
    

   
         If the Company fails to make interest or other payments on the
Subordinated Debt Securities when due (taking account of any Extension Period),
the Declaration provides a mechanism whereby the holders of the Preferred
Securities, using the procedures described in "Description of the Preferred
Securities -- Book-Entry Only Issuance -- The Depository Trust Company" and "--
Voting Rights," may direct the Property Trustee to enforce its rights under the
Subordinated Debt Securities.  If the Property Trustee fails to enforce its
rights under the Subordinated Debt Securities, a holder of Preferred Securities
may institute a legal proceeding against the Company to enforce the Property 
Trustee's rights under the Subordinated Debt Securities without first
instituting any legal proceeding against the Property Trustee or any other
person or entity.  The Company, under the Guarantee, acknowledges that the
Guarantee Trustee will enforce the Guarantee on behalf of the holders of the
Preferred Securities.  If the Company fails to make payments under the
Guarantee, the Guarantee provides a mechanism whereby the holders of the
Preferred Securities may direct the Guarantee Trustee to enforce its rights
thereunder.  If the Guarantee Trustee fails to enforce the Guarantee, any
holder of Preferred Securities may, after such holder makes written request to
the Guarantee Trustee to enforce the Guarantee, institute a legal proceeding
directly against the Company to enforce the Guarantee Trustee's rights under
the Guarantee without first instituting a legal proceeding against the Trust,
the Guarantee Trustee or any other person or entity.
    

   
         The obligations of the Company under the Declaration, the Guarantee,
the Indenture and the Subordinated Debt Securities collectively provide a full 
and unconditional guarantee on a subordinated basis by the Company of payments 
due on the Preferred Securities, to the extent the Trust has funds available
therefor as a result of payments of interest or principal on the Subordinated
Debt Securities.  See "Description of the Guarantee -- General" in the 
accompanying Prospectus.
    





                                      S-36
<PAGE>   37


                     UNITED STATES FEDERAL INCOME TAXATION

GENERAL

         The following summary of certain United States federal income tax
consequences of the purchase, ownership and disposition of the Preferred
Securities is based upon laws, regulations, rulings and decisions now in
effect, all of which are subject to change (with possible retroactive effect)
and possible differing interpretations.  This discussion deals only with
Preferred Securities held as capital assets and does not purport to deal with
persons in special tax situations, such as financial institutions, insurance
companies, regulated investment companies, dealers in securities or currencies,
persons holding Preferred Securities as a hedge against currency risks or as a
position in a "straddle" for tax purposes or as part of a "conversion
transaction," or persons whose functional currency is not the United States
dollar.  This discussion also does not deal with holders other than the
original purchasers of the Preferred Securities or with holders who are not
U.S. Holders (as defined below).  Persons considering the purchase of Preferred
Securities should consult their tax advisors concerning the application of
United States federal income tax laws to their particular situations as well as
any consequences of the purchase, ownership and disposition of the Preferred
Securities arising under the laws of any other taxing jurisdiction.

         As used herein, the term "U.S. Holder" means a beneficial owner of a
Preferred Security that is for United States federal income tax purposes (i) a
citizen or resident of the United States, (ii) a corporation, partnership or
other entity created or organized in or under the laws of the United States or
of any political subdivision thereof, (iii) an estate or trust the income of
which is subject to United States federal income taxation regardless of its
source, or (iv) any other person whose income or gain in respect of a Preferred
Security is effectively connected with the conduct of a United States trade or
business.  As used herein, the term "Non-U.S. Holder" means a holder of a
Preferred Security that is not a U.S. Holder.

CLASSIFICATION OF THE TRUST

         In connection with the issuance of the Preferred Securities, O'Melveny
& Myers, counsel to the Company and the Trust, will render its opinion
generally to the effect that, under then current law and assuming full
compliance with the terms of the Declaration and the Indenture (and certain
other documents), and based on certain facts and assumptions contained in such
opinion, the Trust will be classified for United States federal income tax
purposes as a grantor trust and not as an association taxable as a corporation.
Accordingly, for United States federal income tax purposes, each U.S. Holder of
a Preferred Security will be considered the owner of an undivided interest in
the Subordinated Debt Securities, and each U.S. Holder will be required to
include in its gross income the OID accrued with respect to its allocable share
of those Subordinated Debt Securities.





                                      S-37
<PAGE>   38
CLASSIFICATION OF THE SUBORDINATED DEBT SECURITIES

         Although not entirely free from doubt, the Company believes, after
consultation with counsel, that the Subordinated Debt Securities should be
classified for United States federal income tax purposes as indebtedness.  No
assurance can be given that such position will not be challenged by the
Internal Revenue Service or, if challenged, that such a challenge will not be
successful.  The Company intends to take the position that the Subordinated
Debt Securities will be classified for United States federal income tax
purposes as indebtedness, and by acceptance of a Trust Security, each holder
covenants to treat the Subordinated Debt Securities as indebtedness and the
Preferred Securities as evidence of an indirect beneficial ownership interest
in the Subordinated Debt Securities.  The remainder of this discussion assumes
that the Subordinated Debt Securities will be classified for United States
federal income tax purposes as indebtedness of the Company.

ORIGINAL ISSUE DISCOUNT

         Because the Company has the option, under the terms of the
Subordinated Debt Securities, to defer payments of interest by extending
interest payment periods for up to 20 quarters, all of the stated interest
payments on the Subordinated Debt Securities will be treated as OID.  Holders
of debt instruments issued with OID must include that discount in income on an
economic accrual basis before the receipt of cash attributable to the interest,
regardless of their method of tax accounting.  Generally, all of a U.S.
Holder's taxable interest income with respect to the Subordinated Debt
Securities will be accounted for as OID, and actual distributions of stated
interest will not be separately reported as taxable income.  The amount of OID
that accrues for any quarter will approximately equal the amount of the
interest that accrues on the Subordinated Debt Securities in that quarter at
the stated interest rate.  In the event that the interest payment period is
extended, U.S. Holders will continue to accrue OID approximately equal to the
amount of the interest payment due at the end of an Extension Period on an
economic accrual basis over the length of the Extension Period, even though no
payments of stated interest are being made.

         Corporate U.S. Holders of Preferred Securities will not be entitled to
a dividends-received deduction with respect to any income recognized with
respect to the Preferred Securities.

MARKET DISCOUNT AND BOND PREMIUM

         U.S. Holders other than those who purchase the Preferred Securities
upon their original issuance, may be considered to have acquired their
undivided interests in the Subordinated Debt Securities with market discount,
premium or acquisition premium as such phrases are defined for United States
federal income tax purposes.  Such U.S. Holders are advised to consult their
tax advisors as to the income tax consequences of the acquisition, ownership
and disposition of the Preferred Securities.

RECEIPT OF SUBORDINATED DEBT SECURITIES OR CASH UPON LIQUIDATION OF THE TRUST





                                      S-38
<PAGE>   39

         Under certain circumstances, as described under the caption
"Description of the Preferred Securities -- Tax Event Redemption or
Distribution," Subordinated Debt Securities may be distributed to U.S. Holders
in exchange for the Preferred Securities and in liquidation of the Trust.
Under current law, such a distribution, for United States federal income tax
purposes, would be treated as a non-taxable event to each U.S. Holder, and each
U.S. Holder would receive an aggregate tax basis in the Subordinated Debt
Securities equal to such U.S. Holder's aggregate tax basis in its Preferred
Securities.  A U.S. Holder's holding period in the Subordinated Debt Securities
so received in liquidation of the Trust would include the period during which
the Preferred Securities were held by such U.S. Holder.

         Under certain circumstances, as described under the caption
"Description of the Preferred Securities -- Tax Event Redemption or
Distribution", the Subordinated Debt Securities may be redeemed for cash and
the proceeds of such redemption distributed to U.S. Holders in redemption of
their Preferred Securities.  Under current law, such a redemption would, for
United States federal income tax purposes, constitute a taxable disposition of
the redeemed Preferred Securities, and a U.S. Holder would recognize gain or
loss as if it had sold such redeemed Preferred Securities for cash.  See
"United States Federal Income Taxation -- Sales of Preferred Securities."

SALES OF PREFERRED SECURITIES

         A U.S. Holder that sells a Preferred Security will recognize gain or
loss equal to the difference between its adjusted tax basis in the Preferred
Securities and the amount realized on the sale of such Preferred Securities.  A
U.S. Holder's adjusted tax basis in the Preferred Securities generally will be
its initial purchase price increased by the amount of OID previously includible
in such U.S. Holder's gross income to the date of disposition and decreased by
the amount of payments received on the Preferred Securities (whether
denominated as interest or principal).  Such gain or loss generally will be a
capital gain or loss and generally will be a long-term capital gain or loss if
the Preferred Securities have been held for more than one year.

         The Preferred Securities may trade at a price that does not fully
reflect the value of accrued but unpaid interest with respect to the underlying
Subordinated Debt Securities.  A U.S. Holder that disposes of Preferred
Securities between record dates for payments of distributions thereon will be
required to include accrued but unpaid interest on the Subordinated Debt
Securities through the date of disposition as OID, and to add such amount to
the adjusted tax basis of such U.S. Holder's pro rata share of the underlying
Subordinated Debt Securities deemed disposed of.  To the extent the selling
price is less than such U.S. Holder's adjusted tax basis (which will include,
in the form of OID, all accrued but unpaid interest), such U.S. Holder will
recognize a capital loss.  Subject to certain limited exceptions, capital
losses cannot be applied to offset ordinary income for United States federal
income tax purposes.

NON-U.S. HOLDERS





                                      S-39
<PAGE>   40

         This discussion does not address the tax consequences of the
acquisition, ownership or disposition of a Preferred Security by a Non-U.S.
Holder.  Non-U.S. Holders should consult their tax advisors concerning these
matters.

INFORMATION REPORTING TO U.S. HOLDERS

         Subject to the qualifications discussed below, income on the Preferred
Securities will be reported to U.S. Holders on Forms 1099, which forms should
be mailed to U.S. Holders of Preferred Securities by January 31 following each
calendar year.

         The Trust will be obligated to report annually to Cede & Co., as
holder of record of the Preferred Securities, the OID related to the
Subordinated Debt Securities that accrued during the year.  The Trust currently
intends to report such information on Form 1099 prior to January 31 following
each calendar year even though the Trust is not legally required to report to
record holders until April 15 following each calendar year.  The Underwriters
have indicated to the Trust that, to the extent that they hold Preferred
Securities as nominees for beneficial holders, they currently expect to report
to such beneficial holders on Forms 1099 by January 31 following each calendar
year.  Under current law, holders of Preferred Securities who hold as nominees
for beneficial holders will not have any obligation to report information
regarding the beneficial holders to the Trust.  The Trust, moreover, will not
have any obligation to report to beneficial holders who are not also record
holders.  Thus, beneficial holders of Preferred Securities who hold their
Preferred Securities through the Underwriters will receive Forms 1099
reflecting the income on their Preferred Securities from such nominee holders
rather than the Trust.

BACKUP WITHHOLDING

         Backup withholding of United States federal income tax at a rate of
31% may apply to payments made in respect of, and proceeds from the sale of
Preferred Securities, or Subordinated Debt Securities distributed to Holders of
Preferred Securities who are not "exempt recipients" or who fail to comply with
certain procedures for providing certain identifying information (such as the
Holder's taxpayer identification number) in the required manner.

         Any amounts withheld under the backup withholding rules from a payment
to a Holder would be allowed as a refund or a credit against such Holder's
United States federal income tax provided the required information is furnished
to the Internal Revenue Service.


THE UNITED STATES FEDERAL INCOME TAX DISCUSSION SET FORTH ABOVE IS INCLUDED FOR
GENERAL INFORMATION ONLY AND MAY NOT BE APPLICABLE DEPENDING UPON A HOLDER'S
PARTICULAR SITUATION.  HOLDERS SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT
TO THE TAX CONSEQUENCES TO THEM OF THE PURCHASE, OWNERSHIP AND DISPOSITION OF
THE PREFERRED SECURITIES, INCLUDING THE TAX CONSEQUENCES UNDER STATE,





                                      S-40
<PAGE>   41
LOCAL, FOREIGN AND OTHER TAX LAWS AND THE POSSIBLE EFFECTS OF CHANGES IN UNITED
STATES FEDERAL OR OTHER TAX LAWS.

                                  UNDERWRITING

         Subject to the terms and conditions set forth in the underwriting
agreement (the "Underwriting Agreement"), the Trust has agreed to sell to each
of the Underwriters named below, and each of the Underwriters, for whom
_______________________ are acting as representatives (the "Representatives"),
has severally agreed to purchase the number of Preferred Securities set forth
opposite its name below.  In the Underwriting Agreement, the several
Underwriters have agreed, subject to the terms and conditions set forth
therein, to purchase all the Preferred Securities offered hereby if any of the
Preferred Securities are purchased.  In the event of default by an Underwriter,
the Underwriting Agreement provides that, in certain circumstances, the
purchase commitments of the nondefaulting Underwriters may be increased or the
Underwriting Agreement may be terminated.





<TABLE>
<CAPTION>
                                                                Number of
                 Underwriters                             Preferred Securities
                 ------------                             --------------------
         <S>                                              <C>
         Total                                                    -----
</TABLE>


         The Underwriters propose to offer the Preferred Securities, in part,
directly to the public at the initial public offering price set forth on the
cover page of this Prospectus Supplement, and, in part, to certain securities
dealers at such price less a concession of $____ per Preferred Security.  The
Underwriters may allow, and such dealers may reallow, a concession not in
excess of $____ per Preferred Security to certain brokers and dealers.  After
the Preferred Securities are released for sale to the public, the offering
price and other selling terms may from time to time be varied by the
Representative.

         Because the proceeds of the sale of the Preferred Securities will be
used to purchase the Subordinated Debt Securities of the Company, the
Underwriting Agreement provides that the Company will pay as compensation
("Underwriters' Compensation") to the Underwriters for their services an amount
in New York Clearing House (next day) funds of $_______ per Preferred Security
(or $____________ in the aggregate) for the accounts of the several
Underwriters; provided that such compensation for sales of 10,000 or more
Preferred Securities to a single purchaser will be $______ per Preferred
Security.  Therefore, to the extent of such sales, the actual amount of
Underwriters Compensation will be less than the aggregate amount specified in
the preceding sentence.





                                      S-41
<PAGE>   42

         The Trust and the Company have granted the Underwriters an option
exercisable for 30 days after the date of this Prospectus Supplement to
purchase up to an aggregate of _______, additional Preferred Securities at the
initial public offering price per Preferred Security solely to cover
over-allotments, if any.  If the Underwriters exercise their over-allotment
option, the Underwriters have severally agreed, subject to certain conditions,
to purchase approximately the same percentage thereof that the number of
Preferred Securities to be purchased by each of them, as shown in the foregoing
table, bears to the total Preferred Securities offered.

         During a period of 30 days from the date of the Prospectus Supplement,
neither the Trust nor the Company will, without the prior written consent of
the Underwriters, directly or indirectly, sell, offer to sell, grant any option
for the sale of, or otherwise dispose of, any Preferred Securities, any
security convertible into or exchangeable into or exercisable for Preferred
Securities or Subordinated Debt Securities or any debt securities substantially
similar to the Subordinated Debt Securities or equity securities substantially
similar to the Preferred Securities (except for the Subordinated Debt
Securities and the Preferred Securities offered hereby).

         The Preferred Securities have been approved for listing upon
designation of issuance on the New York Stock Exchange.  Trading of the
Preferred Securities on the New York Stock Exchange is expected to commence
within a 30 day period after the initial delivery of the Preferred Securities.
The Representatives have advised the Trust that it intends to make a market in
the Preferred Securities prior to the commencement of trading on the New York
Stock Exchange.  The Representatives will have no obligation to make a market
in the Preferred Securities, however, and may cease market making activities,
if commenced, at any time.

         Prior to this offering there has been no public market for the
Preferred Securities.  In order to meet one of the requirements for listing the
Preferred Securities on the New York Stock Exchange, the Underwriters will
undertake to sell lots of 100 or more Preferred Securities to a minimum of 400
beneficial holders.

         The Trust and the Company have agreed to indemnify the Underwriters
against, or contribute to payments that the Underwriters may be required to
make in respect of, certain liabilities, including liabilities under the
Securities Act of 1933, as amended.

         Certain of the Underwriters engage in transactions with, and, from
time to time, have performed services for, the Company and its subsidiaries in
the ordinary course of business.

                                 LEGAL MATTERS

         The validity of the Preferred Securities, the Subordinated Debt
Securities, the Guarantee and certain matters relating thereto will be passed
upon for the Company by O'Melveny & Myers and for the Trust by Skadden, Arps,
Meagher & Flom.  Certain legal matters will be passed upon for the Underwriters
by Winthrop, Stimson, Putnam & Roberts.





                                      S-42
<PAGE>   43
Certain United States federal income taxation matters will be passed upon for
the Company and the Trust by O'Melveny & Myers.





                                      S-43


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