COLUMBIA GAS SYSTEM INC
S-3/A, 1996-02-15
NATURAL GAS TRANSMISISON & DISTRIBUTION
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<PAGE>   1
   
As filed with the U.S. Securities and Exchange Commission on February 15, 1996
    
                                         Registration No. 33-64555
                                         Trust Indenture Act File No. 22-22215
================================================================================


                     SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C.  20549
   
                               AMENDMENT NO. 1
    
                              ----------------
                                  FORM S-3
                           REGISTRATION STATEMENT
                                    Under
                         THE SECURITIES ACT OF 1933

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

                        THE COLUMBIA GAS SYSTEM, INC.
           (Exact name of registrant as specified in its charter)

              Delaware                                        13-1594808
     (State or other jurisdiction of                        (I.R.S. Employer
     incorporation or organization)                         Identification No.)

                             20 Montchanin Road
                         Wilmington, Delaware 19807
                               (302) 429-5000
   (Address, including zip code and telephone number, including area code,
                 of registrant's principal executive office)

                              ----------------
                          L. J. BAINTER, TREASURER
                        THE COLUMBIA GAS SYSTEM, INC.
                             20 Montchanin Road
                         Wilmington, Delaware 19807
                               (302) 429-5597
          (Name, address, including zip code, and telephone number,
                 including area code, of agent for service)

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

                                 COPIES TO:

     Gregory M. Shaw, Esq.                            Keith L. Kearney, Esq.
     Cravath, Swaine & Moore                          Davis, Polk & Wardwell
     Worldwide Plaza                                  450 Lexington Avenue
     825 Eighth Avenue                                New York, NY 10017
     New York, NY 10019

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

Approximate date of commencement of proposed sale to the public:  From time to
time after the Registration Statement becomes effective.

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

         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 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 registration
statement for the same offering.  / /

         If delivery of the prospectus is expected to be made pursuant to Rule
434 under the Securities Act, please check the following box.  /x/
   
    
================================================================================
THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES
AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL FILE
A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT
SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF THE
SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
================================================================================
   
    
<PAGE>   2

         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 FEBRUARY 15, 1996.
    


                                 Prospectus

                        THE COLUMBIA GAS SYSTEM, INC.

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

                                 DEBENTURES
                               PREFERRED STOCK
                                COMMON STOCK

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

         The Columbia Gas System, Inc. (the "Company") intends to issue, and
offer for sale, directly, through agents to be designated from time to time, or
through dealers or underwriters also to be designated, (i) one or more series
of its debentures (the "Debentures"), which will be unsecured senior
obligations of the Company, (ii) shares of one or more series of its preferred
stock, par value $10 (the "Preferred Stock") and (iii) shares of its common
stock, par value $10 ("Common Stock" and, collectively with the Debentures and
Preferred Stock, the "Securities"), all having an aggregate initial public
offering price of up to $1,000,000,000 and each of which Securities will be
offered to the public on terms to be determined at the time of sale.  When a
particular offering of Securities is made, a supplement to this Prospectus (a
"Prospectus Supplement") will be delivered together with this Prospectus
setting forth with respect to each offering the following (or the method of
determination, thereof): (i) in the case of Debentures, the aggregate principal
amount offered, denomination, maturity, priority, rate of interest (which may
be fixed or variable), time and place of payment of interest, terms for
optional redemption or repayment by the Company or for sinking fund payments,
terms for any conversion or exchange into other securities, the initial public
offering price, any stock exchange listings, any provisions related to
Debentures issued as medium-term notes, original issue discount or other
special terms, and the designation of the trustee, security registrar and
paying agent, (ii) in the case of Preferred Stock, the specific title and
stated value, number of shares or fractional interests therein, any dividend,
liquidation, redemption, sinking fund, voting or other rights, the terms for
any conversion or exchange into other securities, any stock exchange listings
and the public offering price, (iii) in the case of Common Stock, the aggregate
number of shares offered, the public offering price, any stock exchange listing
and other terms thereof, and (iv) for all offerings of Securities, the
underwriter or underwriters or agent or agents, if any, for such offerings of
Securities, their compensation, the resulting net proceeds to the Company and
any other relevant terms and conditions.  See also  "Descriptions of
Securities" and "Plan of Distribution" herein.

         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 SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION
PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS.  ANY REPRESENTATION TO
THE CONTRARY IS A CRIMINAL OFFENSE.


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




   
THE DATE OF THIS PROSPECTUS IS FEBRUARY 15, 1996.
    




                                      -1-
<PAGE>   3
         NO DEALER, SALESPERSON OR OTHER PERSON HAS BEEN AUTHORIZED TO GIVE ANY
INFORMATION OR TO MAKE ANY REPRESENTATIONS OTHER THAN THOSE CONTAINED OR
INCORPORATED BY REFERENCE IN 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.  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 TO SELL OR A
SOLICITATION OF AN OFFER TO BUY SECURITIES IN ANY JURISDICTION TO ANY PERSON TO
WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR SOLICITATION IN SUCH JURISDICTION.

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

                              TABLE OF CONTENTS
   
<TABLE>
<S>                                                                                                         <C>
AVAILABLE INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  -2-
INCORPORATION OF DOCUMENTS BY REFERENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  -2-
THE COMPANY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  -3-
USE OF PROCEEDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  -4-
RATIO OF EARNINGS TO FIXED CHARGES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  -4-
DESCRIPTIONS OF SECURITIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  -5-
CORPORATE PROVISIONS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -16-
PLAN OF DISTRIBUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -17-
LEGAL OPINIONS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -18-
EXPERTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -18-
</TABLE>
    

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

                             AVAILABLE INFORMATION
   
         The Company is subject to the informational requirements of the
Securities Exchange Act of 1934, as amended ("Exchange Act"), and in accordance
therewith files reports and other information with the Securities and Exchange
Commission ("SEC").  Such reports, proxy statements and other information filed
by the Company can be inspected and copied at the public reference facilities
of the SEC, Room 1024, Judiciary Plaza, 450 Fifth Street, N.W., Washington, DC
20549, as well as at the following SEC Regional Offices:  75 Park Place, New
York, NY 10007 and Kluczynski Federal Building, 230 S. Dearborn Street,
Chicago, IL 60604.  Such material can also be inspected at the New York Stock
Exchange, 20 Broad Street, New York, NY, 10005.  Copies can be obtained from
the SEC by mail at prescribed rates.  Requests should be directed to the SEC's
Public Reference Section, Room 1024, Judiciary Plaza, 450 Fifth Street, N.W.,
Washington, DC 20549.
    
                                ----------------


                    INCORPORATION OF DOCUMENTS BY REFERENCE
   
         The following documents have been filed with the SEC and are
incorporated herein by reference:  (1)  the Company's Annual Report on Form
10-K for the year ended December 31, 1994; (2) the Company's Current Reports on
Form 8-K filed on February 2, 1995, February 10, 1995, February 15, 1995, March
16, 1995, April 17, 1995, April 18, 1995, April 20, 1995, May 1, 1995, June 16,
1995, June 19, 1995, July 18, 1995, July 19, 1995, July 28, 1995, August 4,
1995, October 4, 1995, October 18, 1995, October 20, 1995, October 25, 1995,
November 22, 1995, November 28, 1995, November 30, 1995 and February 8, 1996;
and (3) the Company's Quarterly Reports on Form 10-Q for the quarters ended
March 31, 1995, June 30, 1995 and September 30, 1995.
    

         All documents filed by the Company pursuant to Section 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 any offering of Securities shall be deemed to be
incorporated by reference in this Prospectus and to be a part hereof from the
date of filing of such documents.  Any statement contained herein or in a
document incorporated or deemed to be incorporated by reference herein





                                      -2-
<PAGE>   4
shall be deemed to be modified or superseded for purposes of this Prospectus to
the extent that a statement contained herein or in any subsequently filed
document which also is, or is deemed to be, incorporated by reference herein
modifies or supersedes such statement.  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 Company will provide without charge
to each person to whom a copy of this Prospectus has been delivered, on the
written or oral request of any such person, a copy of any or all of the
documents described above which have been incorporated by reference in this
Prospectus, other than exhibits to such documents.  Requests for copies of such
documents should be directed to The Columbia Gas System, Inc., Attention:
Director, Investor Relations, 20 Montchanin Road, Wilmington, DE 19807 -
telephone (302) 429-5331 or (302) 429-5332.

                                  THE COMPANY
   
         The Company operates one of the largest integrated natural gas systems
in the United States and was organized under the laws of the State of Delaware
on September 30, 1926.  It is a registered holding company under the Public
Utility Holding Company Act of 1935 (the "Holding Company Act") and derives
substantially all its revenues and earnings from the operating results of its
direct subsidiaries.  The Company owns all of the securities of its
subsidiaries except for approximately 8 percent of the stock in Columbia LNG
Corporation ("Columbia LNG").  The Company's subsidiaries are engaged in
natural gas transmission, natural gas distribution, exploration for and
production of oil and natural gas, and other energy operations.
    
   
         On July 31, 1991, the Company and its wholly-owned subsidiary,
Columbia Gas Transmission Corporation ("Columbia Transmission"), filed separate
petitions for protection under Chapter 11 of the Federal Bankruptcy Code in the
U.S. Bankruptcy Court for the District of Delaware (the "Bankruptcy Court").
The Company and Columbia Transmission had operated under the protection of
Chapter 11 of the Federal Bankruptcy Code since their respective bankruptcy
filings on July 31, 1991.  On November 15, 1995, the Bankruptcy Court confirmed
the Third Amended Plan of Reorganization of the Company dated July 27, 1995
("POR") and the Amended Plan of Reorganization of Columbia Transmission dated
July 17, 1995 (the "TCO POR") and emerged from their respective bankruptcy
proceedings.  On November 28, 1995 the Company and Columbia Transmission
consummated the POR and TCO POR, respectively.
    
   
         The Company's two interstate pipeline transmission companies, Columbia
Transmission and Columbia Gulf Transmission Company, operate a 23,200-mile
pipeline network that extends from offshore in the Gulf of Mexico to New York
State and the eastern seaboard.  In addition, Columbia Transmission operates
one of the nation's largest underground natural gas storage systems.
    
   
         Five distribution subsidiaries provide natural gas service to more
than 1.9 million residential, commercial and industrial customers in Ohio,
Pennsylvania, Virginia, Kentucky, and Maryland.  These subsidiaries purchase
gas supplies to serve their high-priority customers and transport gas for
industrial and commercial customers who purchase gas from other sources.  The
distribution subsidiaries operate more than 30,600 miles of pipelines.
    
   
         The Company's two oil and gas subsidiaries explore for, develop,
produce, and market oil and natural gas in the United States.  These companies
hold interests in more than 2.2 million net acres of gas and oil leases and
have proved oil and gas reserves in excess of 609 billion cubic feet of gas
equivalent (Bcfe).   In October 1995, the Company announced its intention to
sell Columbia Gas Development Corporation, its southwest oil and gas
exploration and production subsidiary representing approximately 196 Bcfe of
the above-referenced proved oil and gas reserves.
    
   
         The Company has a subsidiary that is engaged in its nonregulated
natural gas marketing efforts and provides an array of supply and fuel
management services to distribution companies, independent power producers and
other large end users both on and off the transmission and distribution
subsidiaries' pipeline systems.
    
   
         The Company, through another subsidiary, participates in natural
gas-fueled cogeneration projects that produce both electricity and thermal
energy.  In addition, the Company's two propane subsidiaries sell propane at
wholesale and retail to approximately 74,300 customers in eight states.
Another Company subsidiary leases over 500 million tons of coal reserves, much
of which contains less than one percent sulfur.
    




                                      -3-
<PAGE>   5
   
         Columbia LNG is a participant in a partnership that operates a natural
gas peaking service at its LNG facility in Maryland.
    

         Columbia Gas System Service Corporation provides centralized,
cost-efficient data processing, financial, accounting, legal, and other
services for the Company and other subsidiaries.

                                USE OF PROCEEDS
   
         Unless otherwise provided in the applicable Prospectus Supplement, the
net proceeds from the issuance of the Securities will be used for general
corporate purposes, which may include: making distributions to producers and
other creditors whose claims have not been finally determined pursuant to the
TCO POR, refunding securities issued under the POR and financing working
capital requirements and capital expenditures.  The use of proceeds for each
specific issuance of Securities will be described in the applicable Prospectus
Supplement.
    

                       RATIO OF EARNINGS TO FIXED CHARGES

         Both actual and adjusted ratio of earnings to fixed charges for the
Company for each of the twelve months ended September 30, 1995 and September
30, 1994 and for each of the five years ended December 31, are as follows:

<TABLE>
<CAPTION>
                             12 Months Ended September 30,                        Year Ended December 31,             
                             -----------------------------     --------------------------------------------------------
                                 1995         1994                  1994       1993        1992       1991       1990   
                               --------   -----------              ------     ------      ------    --------  ----------
<S>                             <C>           <C>                   <C>         <C>        <C>         <C>       <C>
Actual                          18.38         20.96                 27.44       3.84       12.77       N/A*      1.85
Adjusted                         1.40          1.70                  1.59       1.21         N/A       N/A*      1.85
</TABLE>
   
*        To achieve a one-to-one coverage, the Company would need an additional
         $55.8 million of adjusted earnings in 1992 and an additional $1,313.1
         million of actual, and an additional $1,306.4 million of adjusted
         earnings in 1991.
    

         The actual ratio of earnings to fixed charges was calculated based on
information from the Company's books and records.  In computing the ratio of
earnings to fixed charges, earnings consist of net earnings of the Company and
its consolidated subsidiaries plus taxes on income and fixed charges, plus
dividends received from non-consolidated associated companies accounted for by
the equity method, less interest capitalized net of amount amortized and less
equity earnings of non-consolidated associated companies accounted for by the
equity method.  There were no preferred shares outstanding during any of the
periods indicated and therefore the ratio of earnings to combined fixed charges
and preferred share dividend requirements would have been the same as the ratio
of earnings to fixed charges for each period indicated.

         Adjusted earnings to fixed charges ratios reflect an increase to fixed
charges for an estimate of  interest expense not recorded during bankruptcy in
order to provide more meaningful ratios.  Earnings for all periods except the
twelve months ended December 31, 1990 included interest earned on cash
accumulated during bankruptcy and other bankruptcy related non-recurring items.





                                      -4-
<PAGE>   6
                           DESCRIPTIONS OF SECURITIES

                                   DEBENTURES
   
         The Debentures are to be issued under an Indenture (the "Indenture"),
dated as of  November 28, 1995, between the Company and Marine Midland Bank, as
Trustee (the "Trustee").  The following summary statements with respect to the
Debentures do not purport to be complete and are subject to, and are qualified
in their entirety by reference to, the detailed provisions of the Indenture,
the form of which is filed as an exhibit to the Registration Statement of which
this Prospectus is a part.  Capitalized terms are defined in the Indenture
unless otherwise defined herein.  Whenever any particular section of the
Indenture or any term defined therein is referred to, such section or
definition is incorporated herein by reference.
    

General

   
         The Debentures offered hereby will be limited to an aggregate initial
offering price not to exceed $1,000,000,000.  The Indenture does not limit
the amount of Debentures which can be issued thereunder and provides that
additional Debentures may be issued in one or more series up to the aggregate
principal amount which may be authorized from time to time by the Company's
Board of Directors.  The Debentures will be unsecured senior obligations of the
Company and will rank equally and ratably with all other unsecured
unsubordinated indebtedness of the Company.
    

         Reference is made to the Prospectus Supplement relating to the
particular Debentures offered thereby for the following terms, where
applicable, of the Debentures: (i) the specific designation of the Debentures;
(ii) the denominations in which such Debentures are authorized to be issued;
(iii) the aggregate principal amount of such Debentures ; (iv) the date or
dates on which the principal of such Debentures will mature or the method of
determining such date or dates; (v) the price or prices (expressed as a
percentage of the aggregate principal amount thereof) at which the Debentures
will be issued; (vi) the rate or rates (which may be fixed or variable) at
which such Debentures will bear interest, if any, or the method of calculating
such rate or rates; (vii) the times and places where principal of, premium, if
any, and interest, if any, on such Debentures will be payable; (viii) the date,
if any, after which such Debentures may be redeemed and the redemption prices;
(ix) the date or dates on which interest, if any, will be payable and the
record date or dates therefor or the method by which such date or dates will be
determined; (x) the period or periods within which, the price or prices at
which, and the terms and conditions upon which, such Debentures may be
redeemed, in whole or in part, at the option of the Company; (xi) the
obligations, if any, of the Company to redeem or purchase such Debentures
pursuant to any sinking fund or analogous provisions, upon the happening of a
specified event or at the option of a holder thereof and the period or periods
within which, the price or prices at which and the terms and conditions upon
which, such Debentures will be redeemed or purchased, in whole or in part,
pursuant to such obligations; (xii) if other than the principal amount hereof,
the portion of the principal amount of such Debentures which will be payable
upon declaration of the acceleration of the maturity thereof or the method by
which such portion shall be determined; (xiii) the person to whom any interest
on any such Debenture will be payable if other than the person in whose name
such Debenture is registered on the applicable record date; (xiv) any addition
to, or modification or deletion of, any Event of Default or any covenant of the
Company specified in the Indenture with respect to such Debentures; (xv) the
application, if any, of such means of defeasance or covenant defeasance as may
be specified for such Debentures; (xvi) whether such Debentures are to be
issued in whole or in part in the form of one or more temporary or permanent
global securities and, if so, the identity of the depositary for such global
security or securities; and (xvii) any other special terms pertaining to such
Debentures. Unless otherwise specified in the applicable Prospectus Supplement,
the Debentures will not be listed on any securities exchange.





                                      -5-
<PAGE>   7
         Unless otherwise provided in the applicable Prospectus Supplement,
principal and premium, if any, or interest, if any, will be payable and the
Debentures may be surrendered for payment or transferred at the offices of the
Trustee as paying and authenticating agent, provided that payment of interest
on registered Debentures may be made at the option of the Company by check
mailed to the address of the person entitled thereto as it appears in the
Debenture register.

         Unless otherwise specified in the applicable Prospectus Supplement,
the Debentures will be issued in fully registered form without coupons in
denominations set forth in the Prospectus Supplement.  No service charge will
be made for any transfer or exchange of such Debentures, but the Company may
require payment of a sum sufficient to cover any tax or other governmental
charge payable in connection therewith.

         Some of the Debentures may be issued at a discount (bearing no
interest or interest at below market rates) ("Original Issue Discount
Securities") to be sold at a substantial discount below their stated principal
amount.  Federal income tax consequences and other special considerations
applicable to any such Original Issue Discount Securities will be described in
the applicable Prospectus Supplement.

   
         The Debentures rank pari passu with other debentures issued under the
Indenture and with borrowings under the Company's $1 Billion Credit Agreement
Dated as of November 28, 1995.
    
   
         The Indenture contains no covenants or other provisions that would
afford protection to holders of Debentures in the event of a highly-leveraged
transaction or a change in control of the Company.
    

Restrictive Covenants

Definitions

         "Affiliate" of any specified person means any other person directly or
         indirectly controlling or controlled by or under direct or indirect
         common control with such specified person.  For the purposes of the
         definition, "control" when used with respect to any specified person
         means the power to direct the management and policies of such person
         directly or indirectly, whether through the ownership of voting
         securities, by contract or otherwise; and the terms "controlling" and
         "controlled" have meanings correlative to the foregoing.

   
         "Bankruptcy Law" means Title 11, United States Code, or any similar
         federal or state law for the relief of debtors.
    

         "Consolidated Net Tangible Assets" means the sum of the Net Tangible
         Assets of the Company and its consolidated Subsidiaries after
         eliminating intercompany items.

         "Custodian" means any receiver, trustee, assignee, liquidator,
         custodian or similar official under any Bankruptcy Law.

         "Debt" of any person means, without duplication,

                  (i)    the principal of and premium, if applicable, in
                  respect of (a) indebtedness of such person for money borrowed
                  and (b) indebtedness evidenced by notes, debentures, bonds or
                  other similar instruments for the payment of which such
                  person is responsible;

                  (ii)   all capital lease obligations of such person;





                                      -6-
<PAGE>   8
                  (iii)  all obligations of such person issued or assumed as
                  the deferred purchase price of property (but excluding trade
                  accounts payable arising in the ordinary course of business);

                  (iv)   all obligations of such person for the reimbursement
                  of any obligor on any letter of credit, banker's acceptance
                  or similar credit transaction (other than obligations with
                  respect to letters of credit securing obligations (other than
                  obligations described in (i) through (iii) above) entered
                  into in the ordinary course of business of such person to the
                  extent such letters of credit are not drawn upon or, if and
                  to the extent drawn upon, such drawing is reimbursed no later
                  than the third business day following receipt of a demand for
                  reimbursement following payment on the letter of credit);

                  (v)    all obligations of the type referred to in clauses (i)
                  through (iv) of other persons for the payment of which such
                  person is responsible or liable as obligor or guarantor, and

                  (vi)   all obligations of the type referred to in clauses (i)
                  through (v) of other persons secured by any Lien on any asset
                  of such person (whether or not such obligation is assumed by
                  such person), the amount of any such obligation which is not
                  assumed being deemed to be the lesser of the amortized cost
                  of such assets or the amount of the obligation so secured.

         "Funded Debt" means all Debt of a Significant Subsidiary which matures
         by its terms, or is renewable by such Subsidiary to a date, more than
         one year after the date of its original creation.

         "Lien" means any mortgage, pledge, deposit for security, security
         interest or other similar lien, other than the following: (i) liens
         for taxes or assessments or other local, state or federal governmental
         charges or levies; (ii) any lien to secure obligations under workmen's
         compensation or unemployment insurance laws or similar legislation;
         (iii) any lien to secure performance in connection with bids, tenders,
         contracts (other than contracts for the payment of Debt) or leases
         (other than capital lease obligations) made in the ordinary course of
         business by the Company or any Affiliate thereof; (iv) liens to secure
         public or statutory obligations; (v) materialmen's, mechanics',
         carriers', workmen's, repairmen's, construction, or other liens or
         charges arising in the ordinary course of business; or deposits to
         obtain the release of such liens; (vi) any lien to secure indemnity,
         performance, surety or similar bonds to which the Company or any
         affiliate of the Company is a party; (vii) liens created by or
         resulting from court or administrative proceedings which are currently
         being contested in good faith by appropriate actions or proceedings or
         for the purpose of obtaining a stay or discharge in the course of any
         court or legal proceedings for which appropriate accounting reserves
         have been made to the extent required by generally accepted accounting
         principles; (viii) leases (other than capital lease obligations) made,
         or existing on property acquired, constructed or improved,  in the
         ordinary course of business, together with repairs and additions
         thereto and improvements thereof; (ix) landlords' liens; (x) zoning
         restrictions, easements, licenses, reservations or restrictions in
         respect of currently owned or hereafter acquired, constructed, or
         improved tangible property or defects or irregularities (including any
         terms, conditions, agreements, covenants, exceptions and reservations
         expressed or provided in deeds or other agreements) in title thereto,
         which do not materially impair the conduct of the business of the
         Company; (xi) any of such liens described in clauses (i) through
         (x),whether or not delinquent, whose validity or applicability is at
         the time being contested in good faith by appropriate actions or
         proceedings of the Company or any Subsidiary and for which appropriate
         accounting reserves have been made to the extent required by generally
         accepted accounting principles; (xii) liens securing obligations
         neither assumed by the Company or any Subsidiary nor on account of
         which any of them customarily pays interest directly or indirectly,
         existing, either at the date hereof, or, as to property





                                      -7-
<PAGE>   9
         hereafter acquired, constructed, or improved at the time of
         acquisition, construction or improvement by the Company or a
         Subsidiary; (xiii) any right which any municipal or governmental body
         or agency may have by virtue of any franchise, license, contract or
         statute to purchase, or designate a purchaser of or order the sale of,
         any property of the Company or any Subsidiary upon payment of
         reasonable compensation therefor, or to terminate any franchise,
         license or other rights or to regulate the property and business of
         the Company or any Subsidiary; (xiv) the lien of judgments covered by
         insurance, or upon appeal and covered, if necessary, by the filing of
         an appeal bond, or if not so covered, not exceeding at any one time
         $10,000,000 in aggregate amount; (xv) any lien or encumbrance, moneys
         sufficient for the discharge of which have been deposited in trust
         with the Trustee hereunder or with the trustee or mortgagee under the
         instrument evidencing such lien or encumbrance, with irrevocable
         authority to the Trustee hereunder or to such other trustee or
         mortgagee to apply such moneys to the discharge of such lien or
         encumbrance to the extent required for such purpose; (xvi) rights
         reserved to or vested in others to take or receive any part of the
         gas, by-products of gas or steam or electricity generated or produced
         by or from any properties of the Company or any Subsidiary or with
         respect to any other rights concerning supply, transportation, or
         storage of a commodity which is used in the ordinary course of
         business; and (xvii) liens created or assumed by the Company or a
         Subsidiary in connection with the issuance of debt securities, the
         interest on which is excludable from the gross income of the holders
         of such securities pursuant to Section 103 of the Internal Revenue
         Code of 1986, or any successor section.

         "Net Tangible Assets" as applied to any person on any date shall mean
         the gross book value as shown on the books of such person of all its
         property both real and personal (exclusive of licenses, patents,
         patent applications, copyrights, trademarks, trade names, goodwill,
         experimental or organizational expense and other like intangibles,
         treasury stock and unamortized debt discount and expense but including
         regulatory assets properly recorded on the balance sheet), less all
         reserves for depreciation, obsolescence, depletion and amortization of
         its properties as shown by the books and all other proper reserves
         which in accordance with generally accepted accounting principles
         should be provided in connection with the business conducted.

         "Preferred Stock" as applied to the capital stock of any corporation,
         means stock of any class or classes (however designated) (a) which is
         preferred as to the payment of dividends, or as to the distribution of
         assets on any voluntary or involuntary liquidation or dissolution of
         such corporation, over shares of any other stock of any class of such
         corporation or (b) which contains provisions requiring the mandatory
         redemption of such stock or the mandatory payment of dividends thereon
         or which permit the holders of such stock to put such stock to the
         issuer thereof.

         "Secured Debt" means Debt secured by a Lien.

         "Significant Subsidiary" means a Subsidiary that meets the conditions
         for being classified as a "significant subsidiary" under Regulation
         S-X of the SEC.

         "Subsidiary" means a corporation or limited liability corporation of
         which a majority of the capital stock, having voting power under
         ordinary circumstances to elect directors, is owned by the Company
         and/or one or more Subsidiaries of the Company.





                                      -8-
<PAGE>   10
Limitation on Secured Debt (Section 3.03)

                  The Company has covenanted that it will not issue any Secured
Debt after the date of the Indenture without making effective provision to
ratably secure the Debentures of all series issued and outstanding pursuant to
the Indenture.  The preceding sentence does not require the Company to ratably
secure the Debentures upon the issuance of the following Secured Debt:

                  (1)  Debt of the Company which is incurred to finance the
         acquisition, construction or improvement of assets of the Company and
         its Subsidiaries, which acquisition is consummated, or which
         construction or improvement is commenced, after the date of this
         Indenture; provided, however, that such Debt shall not be secured by
         any assets of the Company other than assets so acquired, constructed
         or improved (together with (i) to the extent the terms of Secured Debt
         so provide, repairs and additions thereto and improvements thereof,
         and (ii) with respect to construction and improvement, any theretofore
         unimproved real property on which the property so constructed or
         improved is located);

                  (2)  Debt of the Company which is secured by assets of a
         person where such Debt was existing at the time such person was merged
         or consolidated with the Company or at the time of sale, other
         disposition, or lease of the properties of such person as an entirety
         (or substantially as an entirety) to the Company; provided, however,
         that such Debt shall not be secured by any assets of the Company other
         than the assets subject thereto at the time of the acquisition
         (together with, to the extent the terms of Secured Debt so provides,
         repairs and additions thereto and improvements thereof);

                  (3)  Debt of the Company issued to refinance such Debt
         incurred under paragraphs (1) and (2) provided that the Debt so issued
         is not secured by a Lien on assets other than those which secure the
         Debt being refinanced (together with, to the extent the terms of new
         Secured Debt so provides, repairs and additions thereto and
         improvements thereof);

                  (4)  Debt of the Company which is secured by inventory,
         accounts receivable, or customers' installment paper, or the proceeds
         thereof, including by means of asset securitization;

   
                  (5)  obligations arising with respect to production payments;
         and
    
   
                  (6)  other Debt which does not exceed, in an aggregate
         principal amount at any one time outstanding, ten percent (10%) of the
         Consolidated Net Tangible Assets of the Company and its consolidated
         Subsidiaries, determined as of the end of the most recent fiscal
         quarter of the Company ending not less than 45 days from the date of
         determination.
    

Limitations on Funded Debt or Preferred Stock of Significant Subsidiaries
(Section 3.04)

         The Company shall not permit any Significant Subsidiary to issue,
directly or indirectly, any Funded Debt or Preferred Stock except:

                  (1)  Funded Debt and Preferred Stock issued and outstanding
         on or prior to the date of the Indenture;

                  (2)  Funded Debt and Preferred Stock issued to and held by
         the Company or a Subsidiary; provided, however, that any subsequent
         issuance or transfer of any common stock which results in any such
         Subsidiary ceasing to be a Subsidiary and any subsequent transfer of
         such Debt or





                                      -9-
<PAGE>   11
         Preferred Stock (other than to the Company or a Subsidiary) shall be
         deemed the issuance of such Debt by the issuer thereof;

                  (3)  Funded Debt and Preferred Stock of a Significant
         Subsidiary issued and outstanding on or prior to the date on which
         such Significant Subsidiary was acquired by the Company or on which it
         became a Significant Subsidiary;

                  (4)  Funded Debt and Preferred Stock issued to finance the
         acquisition by such Significant Subsidiary of any assets or capital
         stock of any person or the construction or improvement of assets of
         such Significant Subsidiary, which acquisition is consummated, or
         which construction or improvement is commenced, after the date of the
         Indenture;

                  (5)  Funded Debt and Preferred Stock issued in exchange for,
         or the proceeds of which are used to refund or refinance, Debt or
         Preferred Stock referred to in the foregoing clauses (1) through (4)
         or to reacquire equity or debt or to repay debt of such Significant
         Subsidiary held by the Company or a Subsidiary;

                  (6)  Funded Debt issued with respect to (a) obligations that
         are tax-exempt pursuant to Section 103 of the Internal Revenue Code of
         1986 as from time to time amended and that are issued in connection
         with pollution control or other facilities of such Significant
         Subsidiary or (b) other obligations, whether taxable or tax-exempt,
         that are issued through any public or governmental authority in
         connection with pollution control or other facilities of such
         Significant Subsidiary;

                  (7)  Funded Debt in an aggregate amount not exceeding the sum
         of (a) total inventory of the Significant Subsidiary; (b) total
         accounts receivable of the Significant Subsidiary; and (c) the total
         amount of customers' installment paper of such Significant Subsidiary,
         determined in accordance with generally accepted accounting
         principles, in each case, as of the end of the most recent fiscal
         quarter of such Significant Subsidiary ending not less than 45 days
         from the date of determination;

   
                  (8)  obligations with respect to production payments; and
    

                  (9)  Funded Debt in an aggregate principal amount and
         Preferred Stock having an aggregate preferential involuntary
         liquidation value, in either case which, when added to the aggregate
         principal amount of Funded Debt of all other Significant Subsidiaries
         (other than Funded Debt referred to in clauses (1) through (8) above)
         and when added to the aggregate preferential involuntary liquidation
         value of Preferred Stock (other than Preferred Stock referred to in
         clauses (1) through (5) above), does not exceed, at any one time
         outstanding, ten percent (10%) of the sum of the Net Tangible Assets
         of such Significant Subsidiary and all other Significant Subsidiaries
         determined on a consolidated basis, as of the end of the most recent
         fiscal quarter of each such Significant Subsidiary ending not less
         than 45 days from the date of determination.

Consolidation, Merger and Sale of Assets (Section 4.01)

         The Company may not consolidate or merge with or into, or transfer or
lease all or substantially all its assets to, any person, unless (i) the person
(if other than the Company) formed by such consolidation or into which the
Company is merged or which acquires or leases all or substantially all the
assets of the Company is organized and existing under the laws of the United
States, any state thereof or the District of Columbia and expressly assumes all
of the Company's obligations under the Debentures and under the





                                      -10-
<PAGE>   12
Indenture; (ii)  immediately after giving effect to such transaction no Event
of Default shall have happened and be continuing; and (iii) certain other
conditions are met.

Secured Debt of Columbia Transmission (Indenture Supplements with Respect to
POR Debentures)

   
         Supplemental Indentures for the Debentures issued pursuant to the POR
contain a covenant requiring the Company, for the period through, and
including, November 27, 1999, to either hold $600 million of Columbia
Transmission Secured Debt or retire (by the means prescribed by the covenant)
Company funded debt in an amount equal to 150% of the amount by which $600
million exceeds the amount of Columbia Transmission Secured Debt held by the
Company.
    

Events of Default (Section 5.01)

                  The following are Events of Default with respect to 
Debentures:

                  (1) default in any payment of interest on any Debenture when
                  the same becomes due and payable and such default continues
                  for a period of 20 days;

                  (2) default in the payment of the principal of any Debenture
                  when the same becomes due and payable at its stated maturity,
                  upon declaration or otherwise;

                  (3) failure to comply with the Indenture provisions relating
                  to the merger, consolidation or transfer of assets;

                  (4) failure to comply with any of its agreements in the
                  Debentures or Indenture (other than those referred to in (1),
                  (2), or (3) above) and such failure continues for 60 days
                  after the notice specified below;

                  (5) the Company has entered against it final, non-appealable
                  court judgments for the payment of money exceeding in the
                  aggregate $50,000,000 in uninsured liability and such
                  judgments are not discharged, paid or adequately provided for
                  within 60 days after the last of such judgments become final
                  and non-appealable;

                  (6) the Company pursuant to or within the meaning of any
                  Bankruptcy Law: (a) commences a voluntary case; (b) consents
                  to the entry of an order for relief against it in an
                  involuntary case; (c) consents to the appointment of a
                  custodian of it or for any substantial part of its property;
                  or (d) makes a general assignment for the benefit of its
                  creditors (collectively, a "Bankruptcy Default"); or

                  (7) a court of competent jurisdiction enters an order or
                  decree under any Bankruptcy Law that: (a) is for relief
                  against the Company in an involuntary case; (b) appoints a
                  Custodian of the Company or for any substantial part of its
                  property; or (c) orders the winding up or liquidation of the
                  Company;  and the order or decree remains unstayed and in
                  effect for 60 days.

                  A default of the type described in clause (4) above is not an
Event of Default until the Trustee or the holders of at least 25% in principal
amount of the Debentures notify the Company of the default and the Company does
not cure the default within the time specified in clause (4) after receipt of
such notice.





                                      -11-
<PAGE>   13
   
         The Company is required to file with the Trustee on an annual basis a
certificate executed by two of its officers stating that the Company is in
compliance with the terms of the Indenture (Section 3.05).
    

Acceleration of Maturity (Section 5.02)

                  If an Event of Default with respect to Debentures occurs and
is continuing, then, and in each and every such case, unless the principal of
all of the Debentures shall have already become due and payable, either the
Trustee or the holders of not less than 25% in principal amount of the
Debentures, by notice in writing to the Company (and to the Trustee if given by
holders), may declare the entire principal amount (or, if the Debentures of
such lesser series are Original Issue Discount Securities, such portion of the
principal as may be specified in the terms of such Original Issue Discount
Securities) of all of the Debentures and any premium and interest accrued
thereof to be due and payable immediately, and upon any such declaration such
principal amount (or specified amount) and any premium and interest accrued
thereon shall become immediately due and payable.  If an Event of Default
specified previously in clause (6) or (7) under the caption "Descriptions of
Securities; Debentures - Events of Default" ("Bankruptcy Defaults") occurs and
is continuing, the principal of and interest on all the Debentures shall ipso
facto become and be immediately due and payable without any declaration or
other act.

                  However, at any time after a declaration of acceleration with
respect to Debentures 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 Debentures may, under certain circumstances, rescind and annul
such acceleration.

                  Reference is made to the Prospectus Supplement relating to
each series of Debentures which are Original Issue Discount Securities for the
particular provision relating to acceleration of the maturity of a portion of
the principal amount of such Original Issue Discount Securities upon the
occurrence of an Event of Default and the continuation thereof.

Waiver and Modification (Section 5.04 and 8.02)

                  The holders of a majority in principal amount of Debentures
may waive any past default under the Indenture with respect to Debentures,
except a default not theretofore cured in the payment of the principal of or
interest on any Debentures or in respect of any provision which under the
Indenture cannot be modified or amended without the consent of the holder of
each Debenture affected.  (Section 5.04).

                  The Indenture contains provisions permitting the Company and
the Trustee to enter into one or more supplemental indentures without the
consent of the holders of any of the Debentures in order (i) to cure any
ambiguity, omission, defect or inconsistency; (ii) to evidence the succession
of another corporation to the Company and the assumption of the covenants of
the Company by a successor to the Company; (iii) to provide for uncertificated
Debentures in addition to or in place of certificated Debentures; (iv) to
comply with requirements of the SEC in connection with qualifying the Indenture
under the Trust Indenture Act of 1939, as amended; (v) to add to the covenants
of the Company for the benefit of holders of Debentures or to surrender any
right or power of the Company; or (vi) to make any change that does not
adversely affect the interests of any holder of Debentures in any material
respect.  (Section 8.01).

                  Modifications and amendments of the Indenture may be made by
the Company and the Trustee with the consent of the holders of a majority in
principal amount of the Debentures outstanding; provided, however, that no such
modification or amendment may, without the consent of the holder of each
Debenture affected thereby, (i) reduce the principal amount of Debentures whose
holders must consent to an amendment; (ii) reduce the rate of or extend the
time for payment of interest on any Debenture; (iii) reduce the principal of or
extend the fixed maturity of any Debenture; (iv) reduce the premium payable
upon the





                                      -12-
<PAGE>   14
   
redemption of any Debenture or change the time at which any Debenture may or
shall be redeemed; (v) make any Debenture payable in money other than that
stated in the Debenture; or (vi) reduce the percentage in principal amount of
Debentures, the consent of the holders of which is required for modification or
amendment of the Indenture or for waiver of certain defaults; and, provided
further, that in case more than one series of Debentures (or Debentures of a
single series which have different terms) are outstanding under the Indenture,
any such proposed amendment affects the rights of holders of Debentures of one
or more series (or Debentures of a single series which have different terms)
and does not affect the rights of holders of the Debentures of one or more of
the other series (or Debentures of a single series which have different terms),
then only holders of Debentures to be affected shall have authority or be
required to consent to or approve such amendment.  Any waiver of a default is
deemed to affect the Debentures of all series, and any modification of the
provisions of any sinking fund or covenant established in respect of Debentures
of a particular series (or Debentures of a single series having the same terms)
are deemed to affect only such Debentures.  (Section 8.02)
    

Satisfaction, Discharge, and Defeasance Prior to Maturity or Redemption
(Sections 7.01 and 7.02)

   
         The Company may, at any time, terminate (i) all its obligations under
the Indenture with respect to the Debentures of a series (such termination by
the Company, a "Legal Defeasance ") or (ii) its obligations to comply with
certain restrictive covenants ("Covenant Defeasance") with respect to the
Debentures of a series, provided that the Company irrevocably deposits in trust
with the Trustee money or U.S. Government Obligations for the payment of
principal of and interest on the Debentures of the series to be defeased to
maturity or redemption, as the case may be.  The conditions to Legal Defeasance
or Covenant Defeasance shall be that (i) no default exists or occurs, (ii) the
Company obtains a certificate from a firm of nationally recognized independent
accountants that the deposited U.S. Government Obligations will be sufficient
to pay principal of and interest on the Debentures to be defeased when due and
(iii) in the case of Legal Defeasance, 91 days pass after the deposit is made
and no Bankruptcy Default with respect to the Company is continuing at the end
of the 91-day period.
    

Federal Income Tax Consequences Related to Defeasance

   
         Under current federal income tax law, a Covenant Defeasance as
described above will not result in a taxable event to any holder of Debentures
or otherwise affect the federal income tax consequence of an investment in
Debentures.
    
   
         The federal income tax treatment of a Legal Defeasance as described
above is not clear.  A Legal Defeasance may be treated as a taxable exchange of
such Debentures for beneficial interests in the trust consisting of the
securities.  In that event, a holder of Debentures would be required to
recognize gain or loss equal to the difference between the holder's adjusted
basis for the Debentures and the fair market value of the holder's beneficial
interest in such trust.  Thereafter, such holder would be required to include
in income a share of the income, gain, and loss of the trust.  Purchasers of
the Debentures should consult their own advisors with respect to the tax
consequences to them of such Legal Defeasance, including the applicability and
effect of tax laws other than federal income tax law.
    

                                PREFERRED STOCK

         The following summary contains a description of certain general terms
of the Company's Preferred Stock to which any Prospectus Supplement may relate.
Certain terms of any series of Preferred Stock that may be offered by any
Prospectus Supplement will be described in the Prospectus Supplement relating
thereto.  If so indicated in the Prospectus Supplement, the terms of any series
may differ from the terms set forth below.  The description of certain
provisions of the Company's Preferred Stock does not purport to be complete and
is subject to and qualified in its entirety by reference to the provisions of
the Company's





                                      -13-
<PAGE>   15
Restated Certificate of Incorporation, as amended (the "Certificate of
Incorporation"), and the Certificate of Designation (the "Certificate of
Designation") relating to each particular series of Preferred Stock which will
be filed by amendment or incorporated by reference, as the case may be, 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 Preferred Stock.

General

   
         Under the Certificate of Incorporation, the Board of Directors of the
Company is authorized, without further stockholder action to provide for the
issuance of up to 40,000,000 shares of Preferred Stock, of which 7,999,494
shares of 7.89% Preferred Stock, Series A, with a liquidation value of $25 per
share and 4,898,946 shares of 5.22% Convertible Preferred Stock, Series B, with
a liquidation value of $40.82 per share were issued and outstanding as of
December 31, 1995.  On February 8, 1996, the Company announced its intent to
redeem the DECS and Preferred Stock on February 26, 1996 as permitted under the
terms of the applicable Certificate of Designation.
    
   
         Additional Preferred Stock may be issued in one or more series, with
such designations or titles; dividend rates; any redemption provisions; special
or relative rights in the event of liquidation, dissolution, distribution or
winding up of the Company; any sinking fund provisions; any conversion
provisions; any voting rights; and any other preferences, privileges, powers,
rights, qualifications, limitations and restrictions, as shall be set forth as
and when established by the Board of Directors of the Company.  The shares of
any series of Preferred Stock will be, when issued, fully paid and
nonassessable and holders thereof will have no preemptive rights in connection
therewith.
    

         The liquidation preference of any series of Preferred Stock is not
necessarily indicative of the price at which shares of such series of Preferred
Stock will actually trade at or after the time of their issuance.  The market
price of any series of Preferred Stock can be expected to fluctuate with
changes in market and economic conditions, the financial condition and
prospects of the Company and other factors that generally influence the market
price of securities.

Rank

         Any series of Preferred Stock will, with respect to rights on
liquidation, winding up and dissolution, rank (i) senior to Common Stock and to
all other equity securities issued by the Company, the terms of which
specifically provide that such equity securities will rank junior to such
series of Preferred Stock (the "Junior Liquidation Securities"); (ii) on a
parity with all equity securities issued by the Company, the terms of which
specifically provide that such equity securities will rank on a parity with
such series of Preferred Stock ("Parity Liquidation Securities"); and (iii)
junior to all equity securities issued by the Company, the terms of which
specifically provide that such equity securities will rank senior to such
series of Preferred Stock (the "Senior Liquidation Securities").  In addition,
any series of Preferred Stock will, with respect to dividend rights, rank (i)
senior to all equity securities issued by the Company, the terms of which
specifically provide that such equity securities will rank junior to such
series of Preferred Stock and, to the extent provided in the applicable
Certificate of Designation, to Common Stock; (ii) on a parity with all equity
securities issued by the Company, the terms of which specifically provide that
such equity securities will rank on a parity with such series of Preferred
Stock and, to the extent provided in the applicable Certificate of Designation,
to Common Stock ("Parity Dividend Securities"); and (iii) junior to all equity
securities issued by the Company, the terms of which specifically provide that
such equity securities will rank senior to such series of Preferred Stock.  As
used in any Certificate of Designation for these purposes, the term "equity
securities" will not include debt securities convertible into or exchangeable
for equity securities.





                                      -14-
<PAGE>   16
Dividends

         Holders of each series of Preferred Stock will be entitled to receive,
when, as and if declared by the Board of Directors of the Company out of funds
legally available therefor, cash dividends at such rates and on such dates as
are set forth in the Prospectus Supplement relating to such series of Preferred
Stock.  Dividends will be payable to holders of record of Preferred Stock as
they appear on the books of the Company on such record dates as shall be fixed
by the Board of Directors.  Dividends on any series of Preferred Stock may be
cumulative or non-cumulative.

         No full dividends may be declared or paid out of funds set apart for
the payment of dividends on any series of Preferred Stock unless dividends
shall have been paid or set apart for such payment on any senior series of
Preferred Stock or on any Parity Dividend Securities.  If full dividends are
not so paid, such series of Preferred Stock shall be subordinated to payment of
dividends on any senior series and shall share dividends pro rata with any
Parity Dividend Securities.

Conversion and Exchange

         The Prospectus Supplement for any series of Preferred Stock will state
the terms, if any, on which shares of that series are convertible into other
securities, including shares of another series of Preferred Stock or Common
Stock, or exchangeable for another series of Preferred Stock, Common Stock or
Debentures of the Company.  The Common Stock of the Company is described below
under "Common Stock".

Liquidation Preference

         Upon any voluntary or involuntary liquidation, dissolution or winding
up of the Company, holders of each series of Preferred Stock that ranks senior
to the Junior Liquidation Securities will be entitled to receive out of assets
of the Company available for distribution to shareholders, before any
distribution is made on any Junior Liquidation Securities, including Common
Stock, distributions upon liquidation in the amount set forth in the Prospectus
Supplement relating to each such series of Preferred Stock.  If the holders of
the Preferred Stock of any series and any other Parity Liquidation Securities
are not paid in full, the holders of the Preferred Stock of such series and the
Parity Liquidation Securities will share ratably in any such distribution of
assets of the Company in proportion to the full liquidation preferences to
which each is entitled.  After payment of the full amount of the liquidation
preference to which they are entitled, the holders of such series of Preferred
Stock will not be entitled to any further participation in any distribution of
assets of the Company.

Voting Rights

         Except as indicated in the Prospectus Supplement relating to a
particular series of Preferred Stock or except as expressly required by
applicable law or the Certificate of Incorporation, the holders of shares of
Preferred Stock will have no voting rights.

Reissuance

         Preferred Stock redeemed or otherwise acquired by the Company will
assume the status of authorized but unissued Preferred Stock and may thereafter
be reissued in the same manner as other authorized but unissued Preferred
Stock.





                                      -15-
<PAGE>   17
                                  COMMON STOCK

   
         The Company has authorized 100,000,000  shares of Common Stock, $10
par value, of which 49,204,025 shares were issued and outstanding as of
December 31, 1995.  The shares of Common Stock currently outstanding are, and
the shares of Common Stock that may be offered hereby will be, fully paid and
nonassessable.
    

         Subject to the rights of the holders of any preferred stock then
outstanding, holders of Common Stock are entitled to one vote per share on all
matters to be voted on by stockholders of the Company, other than the election
of directors.  Voting for directors is cumulative; each stockholder has votes
equal to the number of shares of Common Stock the stockholder owns multiplied
by the number of directors to be elected and all votes can be cast for one
nominee or divided among more than one.

         Subject to the rights of the holders of Preferred Stock, holders of
Common Stock are entitled to receive such dividends, if any, as may be declared
from time to time by the Board of Directors of the Company in its discretion
out of funds legally available therefor.  Upon any liquidation or dissolution
of the Company, holders of the Common Stock are entitled to receive pro rata
all assets remaining available for distribution to stockholders after payment
of all liabilities and provision for the liquidation of any shares of any
Preferred Stock at the time outstanding.  The Common Stock has no preemptive or
other subscription rights, and there are no conversion rights or redemption or
sinking fund provisions with respect to such stock.


                              CORPORATE PROVISIONS

                     RESTATED CERTIFICATE OF INCORPORATION

   
         The Certificate of Incorporation was amended and restated pursuant to
the POR and provides for, among other things: (i) the classification of the
Board of Directors; (ii) a prohibition on the removal of directors except for
cause and then only with a vote of 80% of shares outstanding; and (iii)
stockholder action only to be conducted at a duly called annual or special
meeting of stockholders and not effected by written consent.  The Certificate
of Incorporation also provides that, except as otherwise required by law and
subject to the rights of holders of Preferred Stock, special meetings of
stockholders of the Company may be called only by the Company's Board of
Directors pursuant  to a resolution adopted by a majority of the total number
of authorized members of the Company's Board of Directors.  The classification
of the Board into three classes, each class serving a period of three years,
could delay a holder of shares representing a majority of the voting power from
obtaining control of the Board because such holder would not be able to replace
a majority of the directors prior to, at least, the second annual meeting of
stockholders following the acquisition of such majority interest.  The article
also contains certain super-majority voting requirements with respect to
filling director vacancies and amending certain provisions.
    

         The Certificate of Incorporation requires the Company to indemnify its
directors and officers and certain other persons serving at the request of the
Company to the fullest extent permitted by Delaware law and to advance
litigation expenses and to maintain director and officer liability insurance.
Article V of the Certificate of Incorporation also limits or eliminates the
personal monetary liability of directors and officers for breaches of fiduciary
duty to the fullest extent permitted by Delaware law.

   
         The Company, as a Delaware corporation, is subject to Section 203 of
the Delaware General Corporation Law.  Section 203 discourages efforts by
others to acquire control of the Company through acquisitions of stock or
otherwise, unless the transactions are approved by the Company's Board of
Directors.  It provides that, with certain exceptions, a person who acquires
15% or more of a Company's voting stock (thereby becoming an "interested
stockholder") without board approval may not, for three years thereafter,
             




                                      -16-
<PAGE>   18
engage in a wide range of business combinations with that corporation unless
(i) upon consummation of the transaction the interested stockholder owned at
least 85% of the corporation's voting stock; or (ii) the business combination
is approved by the board of directors and authorized by the affirmative vote of
at least 66 2/3% of the outstanding voting stock not owned by the interested
stockholder.

   
         As a holding company registered under the Holding Company Act, the
Company must obtain the pre-approval by the SEC with respect to the issuance of
its securities under Sections 6 and 7 of the Act and the terms of business
combinations or divestitures involving the stock and assets of the Company or
its regulated subsidiaries under Sections 9 and 10 of the Act.
    

                              PLAN OF DISTRIBUTION

         The Company may sell the Securities being offered hereby in four ways:
(i) directly to purchasers, (ii) through agents, (iii) through underwriters and
(iv) through dealers.

         Offers to purchase Securities may be solicited by the Company and
sales thereof may be made by the Company directly to institutional investors or
others.  The terms of any such sales, including the terms of any bidding or
auction process, if utilized, will be described in the Prospectus Supplement
relating thereto.

         Offers to purchase Securities may be solicited directly by the Company
or by agents designated by the Company from time to time.  Any such agent, who
may be deemed to be an underwriter as that term is defined in the Securities
Act of 1933 (the "Securities Act"), involved in the offer or sale of any
Securities in respect of which this Prospectus is delivered will be named, and
any commissions payable by the Company to such agent will be set forth in the
Prospectus Supplement.  Unless otherwise indicated in the Prospectus
Supplement, any such agent will be acting on a best efforts basis for the
period of its appointment.  Agents 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, or to
contribution to amounts that agents may be required to pay in respect of such
liabilities.  Agents may be customers of, engage in transactions with or
perform services for the Company in the ordinary course of business.

         If an underwriter or underwriters are utilized in the sale of
Securities, the Company will execute an underwriting agreement with such
underwriters at the time of such sale of Securities and the names of the
underwriters and the terms of the transaction will be set forth in the
Prospectus Supplement, which will be used by the underwriters to make resales
of the Securities in respect of which this Prospectus is delivered to the
public.  The underwriters may be entitled, under the relevant underwriting
agreements, to indemnification by the Company against certain liabilities,
including liabilities under the Securities Act, or to contribution to amounts
that underwriters may be required to pay in respect of such liabilities.

         If a dealer is utilized in the sale of the Securities in respect of
which this Prospectus is delivered, the Company will sell such Securities to
such dealer as principal.  Such dealer may then resell such Securities to the
public at varying prices to be determined by such dealer at the time of resale.
Dealers may be entitled to indemnification by the Company against certain
liabilities, including liabilities under the Securities Act, or to contribution
to amounts that dealers may be required to pay in respect of such liabilities.
The name of the dealer, if any, and the terms of the transaction will be set
forth in the Prospectus Supplement.

         If so indicated in the Prospectus Supplement, the Company will
authorize agents and underwriters to solicit offers from certain institutions
to purchase Debentures from the Company at the public offering price set forth
in the Prospectus Supplement pursuant to Delayed Delivery Contracts
("Contracts") providing for payment and delivery on the date stated in the
Prospectus Supplement.  Each Contract will be for an amount not less than, and
unless the Company otherwise agrees the aggregate principal amount of
Debentures sold pursuant to Contracts shall be not less nor more than, the
respective amounts stated in the





                                      -17-
<PAGE>   19
Prospectus Supplement.  Institutions with which Contracts, when authorized, may
be made include commercial and saving banks, insurance companies, pension
funds, investment companies, educational and charitable institutions and other
institutions but shall in all cases be subject to the approval of the Company.
Contracts will not be subject to any conditions except that the purchase by an
institution of the Debentures covered by its Contract shall not at the time of
delivery be prohibited under the laws of any jurisdiction in the United States
to which such institution is subject.  A commission indicated in the Prospectus
Supplement will be paid to underwriters and agents soliciting offers to
purchase Debentures pursuant to Contracts accepted by the Company.

         The place and time of delivery for the Securities in respect of which
this Prospectus is delivered will be set forth in the accompanying Prospectus
Supplement.

                                 LEGAL OPINIONS

         Counsel who are passing upon certain legal matters relating to the
Securities are Cravath, Swaine & Moore, Worldwide Plaza, 825 Eighth Avenue, New
York, NY 10019 for the Company and Davis Polk & Wardwell, 450 Lexington Avenue,
New York, NY 10017 for the Underwriters.

                                    EXPERTS

          Statements made in the Company's Annual Report on Form 10-K for the
year ended December 31, 1994, under the caption "Oil and Gas Operating
Highlights " and in Note 16 of the Notes to Consolidated Financial Statements
incorporated by reference in such Annual Report on Form 10-K, also are
incorporated herein by reference in reliance upon the authority of Ryder Scott
Company Petroleum Engineers, independent petroleum and natural gas consultants,
as experts.

          The consolidated financial statements and schedules incorporated by
reference in, or included in, the Company's Annual Report on Form 10-K for the
year ended December 31, 1994 have been audited by Arthur Andersen LLP,
independent public accountants, as indicated in their reports with respect
thereto, and are incorporated herein in reliance upon the authority of said
firm as experts in accounting and auditing in giving said reports.  Reference
is made to said report which includes an explanatory paragraph that describes
uncertainties which primarily relate to the bankruptcy proceedings of the
Company and Columbia Transmission prior to the effective date of their
respective reorganization plans, including the status of the Company's loans to
Columbia Transmission, certain prepetition asset transfers, the measurement of
certain liabilities and other litigation matters all of which are further
discussed in Note 2 to the consolidated financial statements.





                                      -18-
<PAGE>   20
                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14.

         OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

   
         The following table sets forth those expenses to be incurred by the
Company in connection with the issuance and distribution of the securities
being registered, other than underwriting discounts and commissions.  All of
the amounts shown are estimates, except the applicable SEC registration fee.
    
   
<TABLE>
         <S>                                                                                                     <C>
         Securities and Exchange Commission Filing Fee  . . . . . . . . . . . . . . . . . . . . . . . . .        $     344,828
                                                                                                                              

         Printing of Registration Statement, Prospectus,
          Definitive Debentures and other Miscellaneous Papers  . . . . . . . . . . . . . . . . . . . . .        $     130,000

         Trustee's Charges  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $      10,000

         Legal Fees   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $     225,000

         Independent Public Accountants' Fees and Expenses  . . . . . . . . . . . . . . . . . . . . . . .        $     150,000

         Rating Agency Fees   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $     250,000

         Service Charges, Columbia Gas System Service Corporation   . . . . . . . . . . . . . . . . . . .        $     200,000

         Blue Sky Filing Fees and Expenses  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $      30,000

         Miscellaneous Expenses   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $      50,000

                                                                                                                    ----------

                            Total Expenses  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $   1,389,828
                                                                                                                    ==========
</TABLE>
    

ITEM 15.

         INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the General Corporation Law of the State of Delaware
gives Delaware corporations the power to indemnify present and former officers
and directors under certain circumstances.  Article V of the Certificate of
Incorporation contains provisions which provide for indemnification of certain
persons (including officers and directors).

         Directors and officers liability insurance has been purchased for the
Company's officers and directors, plus directors and officers of subsidiary
companies.  Subject to policy terms and conditions, this insurance indemnifies
individual directors and officers for related costs, damage or charges,
including litigation expenditures, incurred as a result of actual or alleged
wrongful acts.  The coverage also reimburses the Company and its subsidiary
companies for amounts paid by them to indemnify covered directors and officers.
The annual cost of this insurance to the Company and its subsidiary companies
is $1,565,000.





                                      -19-
<PAGE>   21
ITEM 16.

         EXHIBITS

   
         1-A           -Form of Underwriting Agreement.

         4-Q           -Form of Indenture between the Company and Marine
                       Midland Bank, Trustee.

         4-R           -Form of Supplemental Indenture for Debentures.

         4-S           -Indenture dated as of November 28, 1995 between the
                       Company and Marine Midland Bank, Trustee.

         4-T           -First Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         4-U           -Second Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         4-V           -Third Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         4-W           -Fourth Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         4-X           -Fifth Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         4-Y           -Sixth Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         4-Z           -Seventh Supplemental Indenture dated as of November 28,
                       1995 between the Company and Marine Midland Bank,
                       Trustee.

         5             -Opinion of Messrs. Cravath, Swaine & Moore with respect
                       to the legality of the Securities.

         12            -Statement of Ratio of Earnings to Fixed Charges.

         23-A-1        -Written consent of Arthur Andersen LLP, independent
                       public accountants dated November 22, 1995, to the
                       incorporation by reference of their reports dated
                       February 9, 1995, which are included, or incorporated by
                       reference, in the Company's Annual Report on Form 10-K.

         23-A-2        -Written consent of Arthur Andersen LLP, independent
                       public accountants dated February 13, 1996, to the
                       incorporation by reference of their reports dated
                       February 9, 1995, which are included, or incorporated by
                       reference, in the Company's Annual Report on Form 10-K.

         23-B-1        -Letter report, dated February 3, 1995, of Ryder Scott
                       Company Petroleum Engineers, independent petroleum and
                       natural gas consultants to the Company.

         23-B-2        -Written consent, dated January 4, 1996, of Ryder Scott
                       Company Petroleum Engineers, independent petroleum and
                       natural gas consultants to the Company, to the filing
                       and use of information contained in such letter report,
                       which is incorporated by reference in Exhibit 23-B-1, in
                       reports and registration statements to be filed from
                       January 1, 1996 through March 31, 1996.

         23-C          -The consent of Messrs. Cravath, Swaine & Moore, counsel
                       to the Company, appears in their opinion which is filed
                       as Exhibit 5 to this Registration Statement.

         24            -Powers of attorney.

         25            -Statement of eligibility of Trustee.
    




                                      -20-
<PAGE>   22
ITEM 17.

         UNDERTAKINGS

               The undersigned registrant hereby undertakes:

               (1)  To file, during any period in which offers or sales are
                    being made, a post-effective amendment to this Registration
                    Statement:

                    (i) to include any prospectus required by Section 10(a)(3)
                    of the Securities Act;

   
                    (ii) to reflect in the prospectus any facts or events
                    arising after the effective date of the Registration
                    Statement (or the most recent post-effective amendment
                    thereof) which, individually or in the aggregate, represent
                    a fundamental change in the information set forth in the
                    Registration Statement.  Notwithstanding the foregoing, any
                    increase or decrease in volume of securities offered (if
                    the total dollar value of securities offered would not
                    exceed that which was registered) and any deviation from
                    the low or high end of the estimated maximum offering range
                    may be reflected in the form of prospectus filed with the
                    Commission pursuant to Rule 424(b) if, in the aggregate,
                    the changes in volume and price represent no more than a
                    20% change in the maximum aggregate offering price set
                    forth in the "Calculation of Registration Fee" table in the
                    effective registration statement;
    

                    (iii) to include any material information with respect to
                    the plan of distribution not previously disclosed in the
                    Registration Statement or any material change to such
                    information in the Registration Statement;
   
               provided, however, that paragraphs (l)(i) and (l)(ii) do not
               apply if the information required to be included in a
               post-effective amendment by those paragraphs is contained in
               periodic reports filed with or furnished to the SEC by the
               registrant pursuant to Section 13 or 15(d) of the Exchange Act
               that are incorporated by reference in the Registration
               Statement.
    
               (2)  That, for the purpose of determining any liability under
                    the Securities Act, 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, each filing of the registrant's annual
                    report pursuant to Section 13(a) or Section 15(d) of the
                    Exchange Act 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.

                    Insofar as indemnification for liabilities arising under
the Securities Act may be permitted to directors, officers and controlling
persons of the registrant pursuant to the provisions described under Item 15
above, or otherwise, the registrant has been advised that in the opinion of the
SEC such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable.  In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted against the Company by such director, officer or
controlling person in connection with the securities being registered, the
registrant will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question whether such indemnification by it is against public policy as
expressed in the Securities Act and will be governed by the final adjudication
of such issue.





                                      -21-
<PAGE>   23
                                   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 the requirements for filing on Form S-3 and has duly caused this Amendment
No. 1 to the Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the County of New Castle and State
of Delaware on February 15, 1996.
    
                               THE COLUMBIA GAS SYSTEM, INC.
   
                               By     /s/    M. W. O'Donnell  
                                 ------------------------------------------
                                 M. W. O'Donnell, Senior Vice President and
                                                    Chief Financial Officer
    
   
         Pursuant to the requirements of the Securities Act of 1933, this
Amendment No. 1 to the Registration Statement on Form S-3 has been signed below
by the following persons in the capacities and on the dates indicated.
    
   
<TABLE>
<CAPTION>
- ------------------------------------------------------------------------------------------------
Signature                       Title                                 Date
- ------------------------------------------------------------------------------------------------
<S>                             <C>                                   <C>
Oliver G. Richard III           Director (Principal                   February 15, 1996
                                Executive Officer)

Michael W. O'Donnell            Senior Vice President
                                (Principal Financial Officer)

Richard E. Lowe                 Vice President                        By:       /s/     M. W. O'Donnell    
                                (Principal Accounting                    ----------------------------------
                                Officer)                                 (M. W. O'Donnell,
                                                                         Attorney- in Fact)

Richard F. Albosta              Director

Robert H. Beeby                 Director

Wilson K. Cadman                Director

James P. Heffernan              Director

Donald P. Hodel                 Director

Malcolm T. Hopkins              Director

Malcolm Jozoff                  Director

William E. Lavery               Director

Gerald E. Mayo                  Director

Dr. Douglas E. Olesen           Director

Ernesta G. Procope              Director

James R. Thomas, II             Director

William R. Wilson               Director
</TABLE>
    




                                      -22-
<PAGE>   24
                                 EXHIBIT INDEX

          Reference is made in the two right hand columns below to those
exhibits which have heretofore been filed with the Commission.  Exhibits so
referred to are incorporated herein by reference.
   
<TABLE>
<CAPTION>
                                                                                                               Reference
                                                                                                    ------------------------------

                                                                                                    File No.           Exhibit No.
                                                                                                    ---------          -----------
<S>        <C>                                                                                         <C>                  <C>
1-A*       -Form of Underwriting Agreement.

4-Q        -Form of Indenture between the Company and Marine Midland Bank, Trustee.                    33-64555             4-Q

4-R        -Form of Supplemental Indenture for Debentures.                                             33-64555             4-R

4-S*       -Indenture dated as of November 28, 1995 between the Company and Marine Midland
           Bank, Trustee.

4-T*       -First Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

4-U*       -Second Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

4-V*       -Third Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

4-W*       -Fourth Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

4-X*       -Fifth Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

4-Y*       -Sixth Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

4-Z*       -Seventh Supplemental Indenture dated as of November 28, 1995 between the Company
           and Marine Midland Bank, Trustee.

5*         -Opinion of Messrs. Cravath, Swaine & Moore with respect to the legality of the
           Securities.

12*        -Statement of Ratio of Earnings to Fixed Charges.

23-A-1     -Written consent of Arthur Andersen LLP, independent public accountants dated
           November 22, 1995, to the incorporation by reference of their reports dated
           February 9, 1995, which are included, or incorporated by reference, in the
           Company's Annual Report on Form 10-K.                                                       33-64555             24-A

23-A-2*    -Written consent of Arthur Andersen LLP, independent public accountants dated
           February 15, 1996, to the incorporation by reference of their reports dated
           February 9, 1995, which are included, or incorporated by reference, in the
           Company's Annual Report on Form 10-K.

23-B-1     -Letter report, dated February 3, 1995, of Ryder Scott Company Petroleum Engineers,
           independent petroleum and natural gas consultants to the Company.                             1-1098             23-A

23-B-2*    -Written consent, dated January 4, 1996, of Ryder Scott Company Petroleum Engineers,
           independent petroleum and natural gas consultants to the Company, to the filing and use
           of information contained in such letter report, which is incorporated by reference in
           Exhibit 23-B-1, in reports and registration statements to be filed from January 1, 1996
           through March 31, 1996.

23-C*      -The consent of Messrs. Cravath, Swaine & Moore, counsel to the Company,
           appears in their opinion which is filed as Exhibit 5 to this Registration Statement.

24         -Powers of attorney.                                                                        33-64555              25

25         -Statement of eligibility of trustee.                                                       33-64555              26
</TABLE>
    
- -------------
*Filed herewith.





                                      -23-

<PAGE>   1
                                                                     EXHIBIT 1-A





                         The Columbia Gas System, Inc.



                               $[               ]


                             UNDERWRITING AGREEMENT

  
                                                  New York, New York
                                                  [DATE]

To the Representatives
  named in Schedule I
  hereto of the Under-
  writers named in
  Schedule II hereto


Dear Sirs:

         The Columbia Gas System, Inc., a Delaware corporation (the "Company"),
proposes to sell to the underwriters named in Schedule II hereto (the
"Underwriters"), for whom you (the "Representatives") are acting as
representatives, (1) the principal amount, if any, of its debt securities (the
"Debentures") identified in Schedule I hereto, to be issued under an indenture
(the "Indenture") dated as of November 28, 1995, between the Company and Marine
Midland Bank, as Trustee (the "Trustee");  (2) the shares of common stock,
$10.00 par value, of the Company, if any, identified in Schedule I hereto (the
"Common Stock");  (3) the shares of preferred stock, $10.00 par value, of the
Company, if any, identified in Schedule I hereto (the "Preferred Stock").  The
Debentures, Common Stock and Preferred Stock may be sold either separately or
as units (the "units") together with any of the foregoing.  The Debentures,
Common Stock and Preferred Stock shall collectively be referred to herein as
the "Securities".  The Common Stock and Preferred Stock described in Schedule I
hereto shall collectively be referred to herein as the "Equity Securities".  If
the firm or firms listed in Schedule II hereto include only the firm or firms
listed in Schedule I hereto, then the terms "Underwriters" and
"Representatives", as used herein, shall each be deemed to refer to such firm
or firms.
<PAGE>   2
                                                                               2

         1.  Representations and Warranties.  The Company represents and
warrants to, and agrees with, each Underwriter as set forth below in this
Section 1, except that these representations and warranties do not apply to
that part of the Registration Statement which is the Statement of Eligibility
and Qualification under the Trust Indenture Act of 1939 (the "Trust Indenture
Act") (Form T-1) of the Trustee under the Indenture or to statements or
omissions in the Registration Statement, any preliminary prospectus or the
Prospectus based upon information furnished to the Company in writing by any
Underwriter or by the Representatives on behalf of any Underwriter for use
therein. Certain terms used in this Section 1 are defined in paragraph (d)
hereof.

                 (a)  If the offering of the Securities is a Delayed Offering
         (as specified in Schedule I hereto), paragraph (i) below is applicable
         and, if the offering of the Securities is a Non-Delayed Offering (as
         so specified), paragraph (ii) below is applicable.

                           (i)  The Company meets the requirements for the
                 use of Form S-3 under the Securities Act of 1933 (the "Act")
                 and has filed with the U.S. Securities and Exchange Commission
                 (the "Commission") a registration statement (the file number
                 of which is set forth in Schedule I hereto) on such Form,
                 including a base prospectus, for registration under the Act of
                 the offering and sale of the Securities.  The Company may have
                 filed one or more amendments thereto, and may have used a
                 preliminary final prospectus, each of which has previously
                 been furnished to you.  Such registration statement, as so
                 amended, has become effective.  The offering of the Securities
                 is a Delayed Offering and, although the Base Prospectus may
                 not include all the information with respect to the Securities
                 and the offering thereof required by the Act and the rules
                 thereunder to be included in the Final Prospectus, the Base
                 Prospectus includes all such information required by the Act
                 and the rules thereunder to be included therein as of the
                 Effective Date.  The Company will next file with the
                 Commission pursuant to Rules 415 and 424(b)(2) or (5) a final
                 supplement to the form of prospectus included in such
                 registration statement relating to the Securities and the
                 offering thereof.  As filed, such final prospectus supplement
                 shall include all required information with respect to the
                 Securities and the offering thereof and, except to the extent
                 the Representatives shall agree in writing to a modification,
                 shall be in all substantive respects in the form furnished to
                 you prior to the Execution Time or, to the extent not
                 completed at the Execution Time, shall contain only such
                 specific additional information and other changes (beyond that
                 contained in the Base Prospectus and any Preliminary Final
                 Prospectus) as the Company has advised you, prior to the
                 Execution Time, will be included or made therein.
<PAGE>   3
                                                                               3

                           (ii)  The Company meets the requirements for
                 the use of Form S-3 under the Act and has filed with the
                 Commission a registration statement (the file number of which
                 is set forth in Schedule I hereto) on such Form, including a
                 Base Prospectus, for registration under the Act of the
                 offering and sale of the Securities.  The Company may have
                 filed one or more amendments thereto, including a Preliminary
                 Final Prospectus, each of which has previously been furnished
                 to you.  The Company will next file with the Commission either
                 (x) a final prospectus supplement relating to the Securities
                 in accordance with Rules 430A and 424(b)(1) or (4), or (y)
                 prior to the effectiveness of such registration statement, an
                 amendment to such registration statement, including the form
                 of final prospectus supplement.  In the case of clause (x),
                 the Company has included in such registration statement, as
                 amended at the Effective Date, all information (other than
                 Rule 430A Information) required by the Act and the rules
                 thereunder to be included in the Final Prospectus with respect
                 to the Securities and the offering thereof.  As filed, such
                 final prospectus supple ment or such amendment and form of
                 final prospectus supplement shall contain all Rule 430A
                 Information, together with all other such required
                 information, with respect to the Securities and the offering
                 thereof and, except to the extent the Representatives shall
                 agree in writing to a modification, shall be in all
                 substantive respects in the form furnished to you prior to the
                 Execution Time or, to the extent not completed at the
                 Execution Time, shall contain only such specific additional
                 information and other changes (beyond that contained in the
                 Base Prospectus and any Preliminary Final Prospectus) as the
                 Company has advised you, prior to the Execution Time, will be
                 included or made therein.

                 (b)  On the Effective Date, the Registration Statement did or
         will, and when the Final Prospectus is first filed (if required) in
         accordance with Rule 424(b) and on the Closing Date, the Final
         Prospectus (and any supplement thereto) will, comply in all material
         respects with the applicable requirements of the Act, the Securities
         Exchange Act of 1934 (the "Exchange Act") and the Trust Indenture Act
         and the respective rules thereunder; on the Effective Date, the
         Registration Statement did not or will not contain any untrue
         statement of a material fact or omit to state any material fact 
         required to be stated therein or necessary in order to make the 
         statements therein not misleading; on the Effective Date and on the 
         Closing Date the Indenture did or will comply in all material 
         respects with the requirements of the Trust Indenture Act and the 
         rules thereunder; and, on the Effective Date, the Final Prospectus, 
         if not filed pursuant to Rule 424(b), did not or will not, and on the 
         date of any filing pursuant to Rule 424(b) and on the Closing Date, 
         the Final Prospectus (together with any supplement thereto) will not, 
         include any untrue statement of a material fact or
<PAGE>   4
                                                                               4


         omit to state a material fact necessary in order to make the
         statements therein, in the light of the circumstances under which they
         were made, not misleading.

                 (c)  A Declaration and amendments thereto, on Form U-1,
         seeking appropriate orders permitting the issuance and sale of the
         Securities and the transactions related thereto will be or has been
         filed by the Company with the Commission under the Public Utility
         Holding Company Act of 1935.

                 (d)  The terms which follow, when used in this Agreement,
         shall have the meanings indicated.  The term "the Effective Date"
         shall mean each date that the Registration Statement and any
         post-effective amendment or amendments thereto became or become
         effective and each date after the date hereof on which a document
         incorporated by reference in the Registration Statement is filed.
         "Execution Time" shall mean the date and time that this Agreement is
         executed and delivered by the parties hereto.  "Base Prospectus" shall
         mean the prospectus referred to in paragraph (a) above contained in
         the Registration Statement at the Effective Date including, in the
         case of a Non-Delayed Offering, any Preliminary Final Prospectus.
         "Preliminary Final Prospectus" shall mean any preliminary prospectus
         supplement to the Base Prospectus which describes the Securities and
         the offering thereof and is used prior to filing of the Final
         Prospectus.  "Final Prospectus" shall mean the prospectus supplement
         relating to the Securities that is first filed pursuant to Rule 424(b)
         after the Execution Time, together with the Base Prospectus or, if, in
         the case of a Non-Delayed Offering, no filing pursuant to Rule 424(b)
         is required, shall mean the form of final prospectus relating to the
         Securities, including the Base Prospectus, included in the
         Registration Statement at the Effective Date.  "Registration
         Statement" shall mean the registration statement referred to in
         paragraph (a) above, including incorporated documents, exhibits and
         financial statements, as amended at the Execution Time (or, if not
         effective at the Execution Time, in the form in which it shall become
         effective) and, in the event any post-effective amendment thereto
         becomes effective prior to the Closing Date (as hereinafter defined),
         shall also mean such registration statement as so amended. Such term
         shall include any Rule 430A Information deemed to be included therein
         at the Effective Date as provided by Rule 430A.  "Rule 415", "Rule
         424", "Rule 430A" and "Regulation S-K" refer to such rules or
         regulation under the Act. "Rule 430A Information" means information
         with respect to the Securities and the offering thereof permitted to
         be omitted from the Registration Statement when it becomes effective
         pursuant to Rule 430A.  Any reference herein to the Registration
         Statement, the Base Prospectus, any Preliminary Final Prospectus or
         the Final Prospectus shall be deemed to refer to and include the
         documents incorporated by reference therein pursuant to Item 12 of
         Form S-3 which were filed under the Exchange Act on or before the
         Effective Date of the Registration Statement or the issue date of the
         Base Prospectus, any
<PAGE>   5
                                                                               5

         Preliminary Final Prospectus or the Final Prospectus, as the case may
         be; and any reference herein to the terms "amend", "amendment" or
         "supplement" with respect to the Registration Statement, the Base
         Prospectus, any Preliminary Final Prospectus or the Final Prospectus
         shall be deemed to refer to and include the filing of any document
         under the Exchange Act after the Effective Date of the Registration
         Statement or the issue date of the Base Prospectus, any Preliminary
         Final Prospectus or the Final Prospectus, as the case may be, deemed
         to be incorporated therein by reference.  A "Non-Delayed Offering"
         shall mean an offering of securities which is intended to commence
         promptly after the effective date of a registration statement, with
         the result that, pursuant to Rules 415 and 430A, all information
         (other than Rule 430A Information) with respect to the securities so
         offered must be included in such registration statement at the
         effective date thereof.  A "Delayed Offering" shall mean an offering
         of securities pursuant to Rule 415 which does not commence promptly
         after the effective date of a registration statement, with the result
         that only information required pursuant to Rule 415 need be included
         in such registration statement at the effective date thereof with
         respect to the securities so offered.  Whether the offering of the
         Securities is a Non-Delayed Offering or a Delayed Offering shall be
         set forth in Schedule I hereto.

         2.  Purchase and Sale.  (a).  Subject to the terms and conditions and
in reliance upon the representations and warranties herein set forth, the
Company agrees to sell to each Underwriter, and each Underwriter agrees,
severally and not jointly, to purchase from the Company, at the purchase price
set forth in Schedule I hereto the principal amount or number of shares or
Units of Securities set forth opposite such Underwriter's name in Schedule II
hereto, except that, in the case of Debentures, if Schedule I hereto provides
for the sale of such Debentures pursuant to delayed delivery arrangements, the
respective principal amounts of Securities to be purchased by the Underwriters
shall be as set forth in Schedule II hereto less the respective amounts of
Contract Securities determined as provided below.  Securities to be purchased
by the Underwriters are herein sometimes called the "Underwriters' Securities"
and Securities to be purchased pursuant to Delayed Delivery Contracts as
hereinafter provided are herein called "Contract Securities".

         (b).  If so provided in Schedule 1 hereto, the Company shall hereby
grant an option to the several Underwriters to purchase, severally and not
jointly, shares of Common Stock (the "Option Securities") at the purchase price
set forth in Schedule 1.  Said option may be exercised only to cover
over-allotments in the sale of shares of Common Stock by the Underwriters.
Said option may be exercised in whole or in part at any time (but not more than
once) on or before the 30th day after the date of the Final Prospectus upon
written or telegraphic notice by the Representatives to the Company setting
forth the number of shares of the Option Securities as to which the several
Underwriters are exercising the option and the settlement date.  Delivery of
certificates, if
<PAGE>   6
                                                                               6

any, for the shares of Option Securities by the Company, and payment therefor
to the Company, shall be made as provided in Section 3 hereof.  The number of
shares of the Option Securities to be purchased by each Underwriter shall be
the same percentage of the total number of shares of the Option Securities to
be purchased by the several Underwriters as such Underwriter is purchasing of
the aggregate number of shares of Securities to be purchased by the
Underwriters (excluding the Option Securities) as set forth in Schedule II
hereto, subject to such adjustments as you in your absolute discretion shall
make to eliminate any fractional shares.  If Schedule 1 hereto does provide for
an over-allotment option as described above, the term "Securities" as used
herein shall be deemed to include the Option Securities.

         (c).  If so provided in Schedule I hereto, the Underwriters are
authorized to solicit offers to purchase Securities from the Company pursuant
to delayed delivery contracts ("Delayed Delivery Contracts"), substantially in
the form of Schedule III hereto but with such changes therein as the Company
may authorize or approve.  The Underwriters will endeavor to make such
arrangements and, as compensation therefor, the Company will pay to the
Representatives, for the account of the Underwriters, on the Closing Date, the
percentage set forth in Schedule I hereto of the principal amount of the
Securities for which Delayed Delivery Contracts are made.  Delayed Delivery
Contracts are to be with institutional investors, including commercial and
savings banks, insurance companies, pension funds, investment companies and
educational and charitable institutions.  The Company will enter into Delayed
Delivery Contracts in all cases where sales of Contract Securities arranged by
the Underwriters have been approved by the Company (it being understood that
the Company may withhold such approval) but, except as the Company may
otherwise agree, each such Delayed Delivery Contract must be for not less than
the minimum principal amount set forth in Schedule I hereto and the aggregate
principal amount of Contract Securities may not exceed the maximum aggregate
principal amount set forth in Schedule I hereto.  The Underwriters will not
have any responsibility in respect of the validity or performance of Delayed
Delivery Contracts.  The principal amount of Securities to be purchased by each
Underwriter as set forth in Schedule II hereto shall be reduced by an amount
which shall bear the same proportion to the total principal amount of Contract
Securities as the principal amount of Securities set forth opposite the name of
such Underwriter bears to the aggregate principal amount set forth in Schedule
II hereto, except to the extent that you determine that such reduction shall be
otherwise than in such proportion and so advise the Company in writing;
provided, however, that the total prin cipal amount of Securities to be
purchased by all Underwriters shall be the aggregate principal amount set forth
in Schedule II hereto less the aggregate principal amount of Contract
Securities.

         3.  Delivery and Payment.  Delivery of and payment for the
Underwriters' Securities (including the Option Securities if the option
described in Section 2(b) hereof shall have been exercised on or before the
third business day prior to the Closing Date)
<PAGE>   7
                                                                               7

shall be made on the date and at the time specified in Schedule I hereto, which
date and time may be postponed by agreement between the Representatives and the
Company or as provided in Section 8 hereof (such date and time of delivery and
payment for the Underwriters' Securities being herein called the "Closing
Date").  Delivery of such Securities shall be made to the Representatives for
the respective accounts of the several Underwriters against payment by the
several Underwriters through the Representatives of the purchase price thereof
to or upon the order of the Company to the account specified in Schedule I of
the Underwriting Agreement at [          ] bank by wire transfer of Federal
Same Day Funds.  Delivery of such Securities shall be made at such location as
the Representatives shall reasonably designate at least one business day in
advance of the Closing Date, provided that all Debentures shall be delivered
through the DTC book entry system only, unless otherwise specified in Schedule
I, and payment for the Securities shall be made at the office specified in
Schedule I hereto.  Certificates, if any, for such Securities shall be
registered in such names and in such denominations as the Representatives may
request in writing not less than two full business days in advance of the
Closing Date.

         The Company agrees to have the Underwriters' Securities (including the
Option Securities if the option described in Section 2(b) hereof shall have
been exercised on or before the third business day prior to the Closing Date),
if applicable, available for inspection, checking and packaging by the
Representatives in New York, New York, not later than 1:00 PM on the business
day prior to the Closing Date.

         If the option described in Section 2(b) hereof is exercised after the
third business day prior to the Closing Date, the Company will deliver (at the
expense of the Company) to the Representatives, at _____________________, New 
York, New York, on the date specified by the Representatives (which shall be 
within three business days after exerciseof said option), the Option 
Securities against payment of the purchase price thereof to or upon the order 
of the Company to the account specified in Schedule I of the Underwriting 
Agreement at _____________________ bank by wire transfer of Federal Same Day 
Funds.  Certificates, if any, for the Option Securities shall be registered in 
such names and in such denominations as the Representatives shall have 
requested.  If settlement for the Option Securities, if any, occurs after the 
Closing Date, the Company will deliver to the Representatives on the 
settlement date for the Option Securities, and the obligation of the 
Underwriters to purchase the Option Securities shall be conditioned upon 
receipt of, supplemental opinions as to matters set forth in [paragraphs (i) 
and (ii) of Exhibit C] and the Officer's Certificates confirming as of since 
the date of the opinions and Officer's Certificates delivered on the Closing 
Date pursuant to Section 5(d) hereof.
<PAGE>   8
                                                                               8

         4.  Agreements.  The Company agrees with the several Underwriters
that:

                 (a)  The Company will use its best efforts to cause the
         Registration Statement, if not effective at the Execution Time, and
         any amendment thereto, to become effective.  Prior to the termination
         of the offering of the Securities, the Company will not file any
         amendment of the Registration Statement or supplement (including the
         Final Prospectus or any Preliminary Final Prospectus) to the Base
         Prospectus unless the Company has furnished you a copy for your review
         prior to filing.  Subject to the foregoing sentence, the Company will
         cause the Final Prospectus, properly completed, and any supplement
         thereto to be filed with the Commission pursuant to the applicable
         paragraph of Rule 424(b) within the time period prescribed and will
         provide evidence satisfactory to the Representatives of such timely
         filing.  The Company will promptly advise the Representatives (i) when
         the Registration Statement, if not effective at the Execution Time,
         and any amendment thereto, shall have become effective, (ii) when the
         Final Prospectus, and any supplement thereto, shall have been filed
         with the Commission pursuant to Rule 424(b), (iii) when, prior to
         termination of the offering of the Securities, any amendment to the
         Registration Statement shall have been filed or become effective, (iv)
         of any request by the Commission for any amendment of the Registration
         Statement or supplement to the Final Prospectus or for any additional
         information, (v) of the issuance by the Commission of any stop order
         suspending the effectiveness of the Registration Statement or the
         institution or threatening of any proceeding for that purpose and (vi)
         of the receipt by the Company of any notification with respect to the
         suspension of the qualification of the Securities for sale in any
         jurisdiction or the initiation or threatening of any proceeding for
         such purpose.  The Company will use its best efforts to prevent the
         issuance of any such stop order and, if issued, to obtain as soon as
         possible the withdrawal thereof.

                 (b)  If, at any time after the first date of the public
         offering of the Securities when a prospectus relating to the
         Securities is required to be delivered under the Act, any event occurs
         as a result of which the Final Prospectus as then supplemented would
         include any untrue statement of a material fact or omit to state any
         material fact necessary to make the statements therein in the light of
         the circumstances under which they were made not misleading, or if it
         shall be neces sary to amend the Registration Statement or supplement
         the Final Prospectus to comply with the Act or the Exchange Act or the
         respective rules thereunder, the Company promptly will (i) prepare and
         file with the Commission an amendment or supplement which will correct
         such statement or omission or effect such compli ance and (ii) supply
         any supplemented Prospectus to you in such quantities as you may
         reasonably request.
<PAGE>   9
                                                                               9

                 (c)  As soon as practicable, the Company will make generally 
         available to its security holders and to the Representatives an 
         earnings statement or statements of the Company and its subsidiaries 
         which will satisfy the provisions of Section 11(a) of the Act and 
         Rule 158 under the Act.

                 (d)  The Company will furnish to the Representatives and
         counsel for the Underwriters, without charge, copies of the
         Registration Statement (including exhibits thereto) and, so long as
         delivery of a prospectus by an Underwriter or dealer may be required
         by the Act, as many copies of any Preliminary Final Prospectus and the
         Final Prospectus and any supplement thereto as the Representatives may
         reasonably request.  The Company will pay the expenses of printing or
         other production of all documents relating to the offering.

                 (e)  The Company will arrange for the qualification of
         the Securities under the securities or "blue sky" laws of such states
         as the Representatives may reasonably request, and use its best
         efforts to assist the Representatives in securing such qualification
         and to pay all expenses (including fees and disbursements of counsel)
         up to $5,000 in connection with such qualifications and in connection
         with the determination of the eligibility of the Securities for
         investment under the laws of such jurisdictions as the Representatives
         may designate, as well as all filing fees payable in connection with
         the review of the Securities by the National Association of Securities
         Dealers, Inc.;  provided, however, that the Company shall not be
         obligated to qualify as a foreign corporation or as a dealer in
         securities or to execute or file any consent to service of process
         (other than consent with respect to service of process arising in
         connection with the Securities) under the laws of any such state.

                 (f) The Company confirms as of the date hereof that it is
         in compliance with all provisions of Section 1 of Laws of Florida,
         Chapter 92-198, An Act Relating to Disclosure of Doing Business with
         Cuba, and the Company further agrees that if it commences engaging in
         business with the government of Cuba or with any person or affiliate
         located in Cuba after the date the Registration Statement becomes or
         has become effective with the Commission or with the Florida
         Department of Banking and Finance (the "Department"), whichever date
         is later, or if the information reported in the Prospectus, if any,
         concerning the Company's business with Cuba or with any person or
         affiliate located in Cuba changes in any material way, the Company
         will provide the Department notice of such business or change, as
         appropriate, in a form acceptable to the Department.

                 (g) Until the date set forth on Schedule I hereto, the
         Company will not, without the prior written consent of the
         Representatives, offer, sell or contract to sell, or otherwise dispose
         of, directly or indirectly, or announce the offering of,
<PAGE>   10
                                                                              10

         any shares of Common Stock other than the shares offered pursuant
         hereto, or any securities convertible into, or exchangeable for,
         shares of Common Stock; provided, however, that the Company may issue
         and sell Common Stock pursuant to any employee thrift plan, employee
         stock option plan, stock ownership plan, dividend reinvestment plan or
         similar plan of the Company in effect at the Execution Time and the
         Company may issue Common Stock issuable upon the conversion of the
         securities or the exercise of warrants outstanding at the Execution
         Time.

         5.  Conditions to the Obligations of the Underwriters.  The
obligations of the Underwriters to purchase the Underwriters' Securities shall
be subject to the accuracy of the representations and warranties on the part of
the Company contained herein as of the Execution Time and the Closing Date, to
the accuracy of the statements of the Company made in any certificates pursuant
to the provisions hereof, to the performance by the Company of its obligations
hereunder and to the following additional conditions:

                 (a)  If the Registration Statement has not become effective 
         prior to the Execution Time, unless the Representatives agree in 
         writing to a later time, the Registration Statement will become 
         effective not later than (i) 6:00 PM New York City time, on the
         date of determination of the public offering price, if such
         determination occurred at or prior to 3:00 PM New York City time on
         such date or (ii) 12:00 Noon on the business day following the day on
         which the public offering price was determined, if such determination
         occurred after 3:00 PM New York City time on such date; if filing of
         the Final Prospectus, or any supplement thereto, is required pursuant
         to Rule 424(b), the Final Prospectus, and any such supplement, shall
         have been filed in the manner and within the time period required by
         Rule 424(b); and no stop order suspending the effectiveness of the
         Registration Statement shall have been issued and no proceedings for
         that purpose shall have been instituted or threatened.

                 (b)  The Company shall have furnished to the Representatives 
         the opinion of Cravath, Swaine & Moore, counsel for the Company, 
         dated the Closing Date, in substantially the form of Exhibit A, if 
         Debentures are issued, of Exhibit B, if Common Stock is issued, or of 
         Exhibit C, if Preferred Stock is issued.  In rendering such opinion, 
         such counsel may rely (A) as to matters involving the application of 
         laws of any jurisdiction other than the State of New York or the 
         United States, to the extent deemed proper and specified in such 
         opinion, upon the opinion of other counsel of good standing believed 
         to be reliable and who are satisfactory to counsel for the 
         Underwriters and (B) as to matters of fact, to the extent deemed
         proper, on certificates of responsible officers of the Company and
         public officials.  References to the Final Prospectus in this
         paragraph (b) include any supplements thereto at the Closing Date.
<PAGE>   11
                                                                              11

                 (c)  The Representatives shall have received from Davis,
         Polk & Wardwell, counsel for the Underwriters, such opinion or
         opinions, dated the Closing Date, with respect to the issuance and
         sale of the Securities, the Indenture, any Delayed Delivery Contracts,
         the Registration Statement, the Final Prospectus (together with any
         supplement thereto) and other related matters as the Representatives
         may reasonably require, and the Company shall have furnished to such
         counsel such documents as they request for the purpose of enabling
         them to pass upon such matters.

                 (d)  The Company shall have furnished to the Representatives 
         a certificate of the Company, signed by the Chairman of the Board or 
         the President and the principal financial or accounting officer of 
         the Company, dated the Closing Date, to the effect that the signers 
         of such certificate have carefully examined the Registration 
         Statement, the Final Prospectus, any supplement to the Final 
         Prospectus and this Agreement and that:

                          (i) the representations and warranties of the
                 Company in this Agreement are true and correct in all
                 material respects on and as of the Closing Date with the
                 same effect as if made on the Closing Date and the
                 Company has complied with all the agreements and
                 satisfied all the conditions on its part to be performed
                 or satisfied at or prior to the Closing Date;
                 
                          (ii) no stop order suspending the
                 effectiveness of the Registration Statement has been
                 issued and no proceedings for that purpose have been
                 instituted or, to the Company's knowledge, threatened;
                 and
                 
                          (iii) since the date of the most recent
                 financial statements included in the Final Prospectus
                 (exclusive of any supplement thereto), there has been no
                 material adverse change in the condition (financial or
                 other), earnings, business or properties of the Company
                 and its subsidiaries, whether or not arising from
                 transactions in the ordinary course of business, except
                 as set forth in or contemplated in the Final Prospectus
                 (exclusive of any supplement thereto).
                 
                 (e)  At the Closing Date, Arthur Anderson LLP shall have
         furnished to the Representatives a letter or letters (which may refer
         to letters previously delivered to one or more of the
         Representatives), dated as of the Closing Date, in form and substance
         satisfactory to the Representatives, confirming that they are
         independent accountants within the meaning of the Act and the Exchange
         Act and the
<PAGE>   12
                                                                              12

         respective applicable published rules and regulations thereunder and
         containing statements and information of the type ordinarily included
         in accountants' "comfort letters" to underwriters with respect to the
         financial statements and certain financial information contained in or
         incorporated by reference into the Registration Statement and the
         Prospectus.

                 References to the Prospectus in this paragraph (e)
         include any supplement thereto at the date of the letter.

                 In addition, except as provided in Schedule I hereto, at
         the Execution Time, Arthur Andersen LLP shall have furnished to the
         Representatives a letter or letters, dated as of the Execution Time,
         in form and substance satisfactory to the Representatives, to the
         effect set forth above.

                 (f)  Subsequent to the Execution Time or, if earlier, the
         dates as of which information is given in the Registration Statement
         (exclusive of any amendment thereof) and the Final Prospectus
         (exclusive of any supplement thereto), there shall not have been any
         change in the results of operations, the financial condition or
         affecting the business or properties of the Company and its
         subsidiaries the effect of which is, in the reasonable  judgment of
         the Representatives, so material and adverse to the Company and its
         subsidiaries taken as a whole, as to make it impractical or
         inadvisable to proceed with the offering or delivery of the Securities
         as contemplated by the Registration Statement (exclusive of any
         amendment thereof) and the Final Prospectus (exclusive of any
         supplement thereto).

                 (g)  The Company shall have accepted Delayed Delivery
         Contracts in any case where sales of Contract Securities arranged by
         the Underwriters have been approved by the Company.

         If any of the conditions specified in this Section 5 shall not have
been fulfilled in all material respects when and as provided in this Agreement,
or if any of the opinions and certificates mentioned above or elsewhere in this
Agreement shall not be in all material respects reasonably satisfactory in form
and substance to the Representatives and counsel for the Underwriters, this
Agreement and all obligations of the Underwriters hereunder may be canceled at,
or at any time prior to, the Closing Date by the Representatives. Notice of
such cancellation shall be given to the Company in writing or by telephone or
telegraph confirmed in writing.

         The documents required to be delivered by this Section 5 shall be
delivered at the office of Cravath, Swaine & Moore, counsel for the Columbia
Gas System, Inc., at Worldwide Plaza, 825 Eighth Avenue, New York, New York, on
the Closing Date.
<PAGE>   13
                                                                              13

         6.  Reimbursement of Underwriters' Expenses.  If the sale of the
Securities provided for herein is not consummated because any condition to the
obligations of the Underwriters set forth in Section 5 hereof is not satisfied,
or because of any refusal, inability or failure on the part of the Company to
perform any agreement herein or comply with any provision hereof other than by
reason of a default by any of the Underwriters, the Company will reimburse the
Underwriters severally upon demand for all out-of-pocket expenses (including
reasonable fees and disbursements of counsel) that shall have been incurred by
them in connection with the proposed purchase and sale of the Securities.

         7.  Indemnification and Contribution.  (a)  The Company agrees to
indemnify and hold harmless each Underwriter, the directors, officers,
employees and agents of each Underwriter and each person, if any, who controls
any Underwriter within the meaning of either the Act or the Exchange Act
against any and all losses, claims, damages or liabilities, joint or several,
to which they or any of them may become subject under the Act, the Exchange Act
or other Federal or state statutory law or regulation, at common law or
otherwise, insofar as such losses, claims, damages or liabilities (or actions
in respect thereof) arise out of or are based upon any untrue statement or
alleged untrue statement of a material fact contained in the registration
statement for the registration of the Securities as originally filed or in any
amendment thereof, or in the Base Prospectus, any Preliminary Final Prospectus
or the Final Prospectus (if used within the period set forth in paragraph (b)
of Section 4 hereof and as amended or supplemented if the Company shall have
furnished any amendments or supplements thereto) or arising out of or based
upon the omission or alleged omission to state therein a material fact required
to be stated therein or necessary to make the statements therein not
misleading, and agrees to reimburse each such indemnified party, as incurred,
for any legal or other expenses reasonably incurred by them in connection with
investigating or defending any such loss, claim, damage, liability or action;
provided, however, that the Company will not be liable in any such case to the
extent that any such loss, claim, damage or liability arises out of or is based
upon any such untrue statement or alleged untrue statement or omission or
alleged omission made therein in reliance upon and in conformity with written
information furnished to the Company by or on behalf of any Underwriter through
the Representatives specifically for inclusion therein, or arises out of, or is
based upon, statements in or omissions from the part of the Registration
Statement which shall constitute the Statement of Eligibility and Qualification
under the Trust Indenture Act (Form T-1) of the Trustee under the Indenture;
and provided further, however, that indemnification with respect to any
Preliminary Prospectus shall not inure to the benefit of any Underwriter from
whom the person asserting any such losses, claims, damages or liabilities
purchased the Securities which are the subject thereof (or to the benefit of
any person controlling such Underwriter), if such Underwriter (or the
Representatives on behalf of such Underwriter) failed to send or give a copy of
the Final Prospectus (as amended or supplemented if the Company shall have made
any amendments or
<PAGE>   14
                                                                              14

supplements thereto which have theretofore been furnished to the
Representatives or such Underwriter), excluding any documents incorporated by
reference therein, to such person at or prior to the written confirmation of
the sale of such Securities to such person.  This indemnity agreement will be
in addition to any liability which the Company may otherwise have.

                 (b)  Each Underwriter severally agrees to indemnify and
         hold harmless the Company, each of its directors, each of its officers
         who signs the Registration Statement, and each person who controls the
         Company within the meaning of either the Act or the Exchange Act, to
         the same extent as the foregoing indemnity from the Company to each
         Underwriter, but only with reference to written information relating
         to such Underwriter furnished to the Company by or on behalf of such
         Underwriter through the Representatives specifically for inclusion in
         the documents referred to in the foregoing indemnity.  This indemnity
         agreement will be in addition to any liability which any Underwriter
         may otherwise have.

                 (c)  Promptly after receipt by an indemnified party under
         this Section 7 of notice of the commencement of any action, such
         indemnified party will, if a claim in respect thereof is to be made
         against the indemnifying party under this Section 7, notify the
         indemnifying party in writing of the commencement thereof. The
         indemnifying party shall be entitled to appoint counsel of the
         indemnifying party's choice at the indemnifying party's expense to
         represent the indemnified party in any action for which
         indemnification is sought (in which case the indemni fying party shall
         not thereafter be responsible for the fees and expenses of any
         separate counsel retained by the indemnified party or parties except
         as set forth below); provided, however, that such counsel shall be
         reasonably satisfactory to the indemnified party.  Notwithstanding the
         indemnifying party's election to appoint counsel to represent the
         indemnified party in an action, the indemnified party shall have the
         right to employ separate counsel (including local counsel), but the
         fees and expenses of such counsel shall be at the expense of such
         indemnified party unless (i) the indemnifying party and the
         indemnified party shall have mutually agreed to the retention of such
         counsel or, (ii) the named parties to any such proceeding include both
         the indemnified party and the indemnifying party and representation of
         both parties by the same counsel would be in appropriate due to actual
         or potential differing interests between them, or (iii) the
         indemnifying party shall authorize the indemnified party to employ
         separate counsel at the expense of the indemnifying party.  It is
         understood that the indemnifying party shall not, in connection with
         any proceeding or related proceedings in the same jurisdiction, be
         liable for the reasonable fees and expenses of more than one separate
         firm (in addition to one local counsel in each such jurisdiction) for
         all such indemnified parties, and that all such fees and
<PAGE>   15
                                                                              15

         expenses shall be reimbursed as they are incurred.  Such firm shall be
         designated in writing by the Representatives in the case of parties
         indemnified pursuant to the second preceding paragraph and by the
         Company in the case of parities indemnified pursuant to the first
         preceding paragraph.  The indemnifying party shall not be liable for
         any settlement of any proceeding effected without its written consent
         but if settled with such consent or if there be a final judgment for
         the plaintiff, the indemnifying party agrees to indemnify the
         indemnified party from and against any loss or liability by reason of
         such settlement or judgment.

                 (d)  In the event that the indemnity provided in paragraph 
         (a) or (b) of this Section 7 is unavailable or insufficient to hold 
         harmless to the extent provided for in paragraphs (a) and (b) hereof 
         to an indemnified party for any reason, the Company and the
         Underwriters agree to contribute to the aggregate losses, claims,
         damages and liabilities (including legal or other expenses reasonably
         incurred in connection with investigating or defending same)
         (collectively "Losses") to which the Company and one or more of the
         Underwriters may be subject in such proportion as is appropriate to
         reflect the relative benefits received by the Company and by the
         Underwriters from the offering of the Securities; provided, however,
         that in no case shall any Underwriter (except as may be provided in
         any agreement among underwriters relating to the offering of the
         Securities) be responsible for any amount in excess of the
         underwriting discount or commission applicable to the Securities
         purchased by such Underwriter hereunder.  If the allocation provided
         by the immediately preceding sentence is unavailable for any reason,
         the Company and the Underwriters shall contribute in such proportion
         as is appropriate to reflect not only such relative benefits but also
         the relative fault of the Company and of the Underwriters in
         connection with the statements or omissions which resulted in such
         Losses as well as any other relevant equitable considerations.
         Benefits received by the Company shall be deemed to be equal to the
         total net proceeds from the offering (before deducting expenses), and
         benefits received by the Underwriters shall be deemed to be equal to
         the total underwriting discounts and commissions, in each case as set
         forth on the cover page of the Final Prospectus.  Relative fault shall
         be determined by reference to whether any alleged untrue statement or
         omission relates to information provided by the Company or the
         Underwriters.  The Company and the Underwriters agree that it would
         not be just and equitable if contribution were determined by pro rata
         allocation or any other method of allocation which does not take
         account of the equitable considerations referred to above.
         Notwithstanding the provisions of this para graph (d), no person
         guilty of fraudulent misrepresentation (within the meaning of Section
         11(f) of the Act) shall be entitled to contribution from any person
         who was not guilty of such fraudulent misrepresentation.  For purposes
         of this Section 7, each person who controls an Underwriter within the
         meaning of either the Act or the Exchange Act and each director,
         officer, employee and agent
<PAGE>   16
                                                                              16

         of an Underwriter shall have the same rights to contribution as such
         Underwriter, and each person who controls the Company within the
         meaning of either the Act or the Exchange Act, each officer of the
         Company who shall have signed the Registration Statement and each
         director of the Company shall have the same rights to contribution as
         the Company, subject in each case to the applicable terms and
         conditions of this paragraph (d).

         8.  Default by an Underwriter.  If any one or more Underwriters shall
fail to purchase and pay for any of the Securities agreed to be purchased by
such Underwriter or Underwriters hereunder and such failure to purchase shall
constitute a default in the performance of its or their obligations under this
Agreement, the remaining Underwriters shall be obligated severally to take up
and pay for (in the respective proportions which the amount of Securities set
forth opposite their names in Schedule II hereto bears to the aggregate amount
of Securities set forth opposite the names of all the remaining Underwriters)
the Securities which the defaulting Underwriter or Underwriters agreed but
failed to purchase; provided, however, that in the event that the aggregate
amount of Securities which the defaulting Underwriter or Underwriters agreed
but failed to purchase shall exceed 10% of the aggregate amount of Securities
set forth in Schedule II hereto, the remaining Underwriters shall have the
right to purchase all, but shall not be under any obligation to purchase any,
of the Securities, and if such nondefaulting Underwriters do not purchase all
the Securities, this Agreement will terminate without liability to any
nondefaulting Underwriter or the Company.  In the event of a default by any
Underwriter as set forth in this Section 8, the Closing Date shall be postponed
for such period, not exceeding seven days, as either the Representatives or the
Company shall determine in order that the required changes in the Registration
Statement and the Final Prospectus or in any other documents or arrangements
may be effected.  Nothing contained in this Agreement shall relieve any
defaulting Underwriter of its liability, if any, to the Company and any
nondefaulting Underwriter for damages occasioned by its default hereunder.

         9.  Termination.  This Agreement shall be subject to termination, in
the absolute discretion of the Representatives, by notice given to the Company
prior to delivery of and payment for the Securities, if prior to such time (i)
trading in the Company's Common Stock shall have been suspended by the
Commission or the New York Stock Exchange or trading in securities generally on
the New York Stock Exchange shall have been suspended or materially limited,
(ii) a banking moratorium shall have been declared either by Federal or New
York State authorities or (iii) there shall have occurred any outbreak or
escalation of hostilities, declaration by the United States of a national
emergency or war or other calamity or crisis the effect of which on financial
markets is such as to make it, impracticable, in the reasonable judgement of
the Representatives, or inadvisable to proceed with the offering or delivery of
the Securities as contemplated by the Final Prospectus (exclusive of any
supplement thereto).
<PAGE>   17
                                                                              17

         10.  Representations and Indemnities to Survive. The respective
agreements, representations, warranties, indemnities and other statements of
the Company or its officers and of the Underwriters set forth in or made
pursuant to this Agreement will remain in full force and effect, regardless of
any investigation made by or on behalf of any Underwriter or the Company or any
of the officers, directors or controlling persons referred to in Section 7
hereof, and will survive delivery of and payment for the Securities. The
provisions of Sections 6 and 7 hereof shall survive the termination or
cancellation of this Agreement.

         11.  Notices.  All communications hereunder will be in writing and
effective only on receipt, and, if sent to the Representatives, will be mailed,
delivered or telegraphed and confirmed to them, at the address specified in
Schedule I hereto; or, if sent to the Company, will be mailed, delivered or
telegraphed and confirmed to it at Carolyn M. Afshar, Secretary, attention of
the legal department.

         12.  Successors.  This Agreement will inure to the benefit of and be
binding upon the parties hereto and their respective successors and the
officers and directors and controlling persons referred to in Section 7 hereof,
and no other person will have any right or obligation hereunder.

         13.  Applicable Law.  This Agreement will be governed by and construed
in accordance with the laws of the State of New York without reference to
principles of conflicts of laws.
<PAGE>   18
                                                                              18

         If the foregoing is in accordance with your understanding of our
agreement, please sign and return to us the  enclosed duplicate hereof,
whereupon this letter and your acceptance shall represent a binding agreement
among the Company and the several Underwriters.

                                            Very truly yours,
                                            
                                            Corporation
                                            
                                            
                                            
                                            By:
                                               ------------------------------
                                                           [Title]
                                            
The foregoing Agreement is                  
hereby confirmed and accepted               
as of the date specified in                 
Schedule I hereto.                          
                                            
                                            
By:                                         
    --------------------------------
                [Title]               
                                            
                                            
By:                                         
    -------------------------------
                [Title]               
                                            
For themselves and the other                
several Underwriters, if any,               
named in Schedule II to the                 
foregoing Agreement.                        
                                            
         or                                 
                                            
                                            
By:                                         
    -------------------------------
                [Title]               
                                            
For itself and the other                    
several Underwriters, if any,               
named in Schedule II to the                 
foregoing Agreement.                        
<PAGE>   19
                                                                       EXHIBIT A


               Form of Opinion of Special Counsel to the Company


         The opinion of ____________________, counsel to the Company, to be
delivered pursuant to Section 5(b) of the document entitled The Columbia Gas
System, Inc., Underwriting Agreement Standard Provisions (Debentures) shall be
to the effect that:

               (i)  the Company has been duly incorporated, is validly existing
         as a corporation in good standing under the laws of the State of
         Delaware and has due corporate authority to carry on the business in
         which it is engaged;

               (ii) the Indenture has been duly authorized, executed and
         delivered by the Company and is a valid and binding agreement of the
         Company;

               (iii) the Indenture has been duly qualified under the Trust
         Indenture Act;

               (iv)  the Debentures have been duly authorized, and when
         executed and authenticated in accordance with the provisions of the
         Indenture and delivered to the Underwriters against payment of the
         agreed consideration therefor, will be valid and binding obligations
         of the Corporation;

               (v)  the Underwriting Agreement has been duly authorized,
         executed and delivered by the Company and is a valid and binding
         agreement of the Company, except as rights to indemnity thereunder may
         be limited by applicable law;

               (vi)  the execution, delivery and performance of the
         Underwriting Agreement will not contravene any provision of applicable
         law or regulation or the Restated Certificate of Incorporation or
         By-Laws, as amended, of the Company;

               (vii)  the statements in the Prospectus under "Description of
         Debentures" and "Certain Terms and Description of Debentures and
         Indenture", insofar as such statements constitute a summary of the
         documents referred to therein, fairly present the information called
         for with respect to such documents;

               (viii) the Registration Statement and the prospectus (except for
         the financial statements and other financial and statistical
         information included therein, as to which we do not express any
         opinion) comply as to form in all material respects with the
         requirements of the Securities Act and the rules and regulations of
         the Commission thereunder; and
<PAGE>   20
                                                                              20

               (ix)  the Registration Statement is effective under the
         Securities Act of 1933 and to the best of such counsel's knowledge, no
         proceeding for a stop order with respect thereto is pending or
         threatened under Section 8(d) of the Securities Act of 1933.

               (x)  In passing upon the form of the Registration Statement and
         Prospectus, such counsel has necessarily assumed the correctness and
         completeness of the statements made therein and take no responsibility
         therefor, except so far as the statements relate to such counsel,
         except as set forth in the preceding subparagraph (vii) and except
         that such counsel is of the opinion that the statements contained in
         the Corporation's Annual Report on Form 10-K for the year ended 1994
         under the caption "Business--Public Utility Holding Company Act",
         insofar as they relate to the regulation and status of the Company and
         its subsidiary companies under the Public Utility Holding Company Act
         of 1935, are correct as to matters of law and legal conclusions.
         However, in the course of the preparation by the Company of the
         Registration Statement and the Prospectus (the documents incorporated
         therein by reference having previously been filed by the Company),
         such counsel participated in conferences with officers of the Company
         with respect thereto, and such counsel's examination of the
         Registration Statement and the Prospectus and such counsel's
         discussions in the above-mentioned conferences did not disclose any
         information which gave such counsel reason to believe that the
         Registration Statement (except for the financial statements and other
         financial data contained therein, as to which such counsel does not
         express any opinion), as of its effective date, contained any untrue
         statement of a material fact or omitted to state any material fact
         required to be stated therein or necessary to make the statements
         therein not misleading, or that the Prospectus (except for the
         financial statements and other financial data contained therein, as to
         which such counsel does not express any opinion), at the date of the
         Prospectus Supplement and at the date hereof, included any untrue
         statement of a material fact or omitted to state any material fact
         necessary in order to make the statements therein, in the light of the
         circumstances under which they were made, not misleading.  Counsel
         neither represents nor is consulted by the Company with respect to the
         Federal Energy Regulatory Commission and other regulatory matters,
         and, due to the complexity of such matters and the comprehensive
         knowledge thereof required in order to evaluate their significance to
         the Company, in making the statement set forth in the previous
         sentence counsel has, to the extent such statement relates to such
         matters, relied solely upon the opinion of the General Counsel of
         Columbia Gas Transmission Corporation, delivered contemporaneously
         herewith.
<PAGE>   21
                                                                       EXHIBIT B


               Form of Opinion of Special Counsel to the Company


         The opinion of ____________________, counsel to the Company, to be
delivered pursuant to Section 5(b) of the document entitled The Columbia Gas
System, Inc., Underwriting Agreement Standard Provisions (Common Stock) shall
be to the effect that:

               (i)  the Company has been duly incorporated, is validly existing
         as a corporation in good standing under the laws of the State of
         Delaware and has due corporate authority to carry on the business in
         which it is engaged;

               (ii)  the Securities have been duly authorized, and when issued
         and delivered to and paid for by the Underwriters in accordance with
         the terms of the Underwriting Agreement, will have been validly
         issued;

               (iii)  the Underwriting Agreement has been duly authorized,
         executed and delivered by the Company and is a valid and binding
         agreement of the Company, except as rights to indemnity thereunder may
         be limited by applicable law;

               (iv)  the performance of the Underwriting Agreement will not
         contravene any provision of applicable law or regulation or the
         certificate of incorporation or by-laws of the Company and no consent,
         approval or authorization of any governmental body or agency is
         required for the performance by the Corporation of its obligations
         under the Underwriting Agreement, except that Counsel does not express
         any opinion with respect to such consent, approval or authorization as
         may be required under (a) the Natural Gas Act, as amended, or the
         Natural Gas Policy Act or the rules, regulations, orders or official
         pronouncements of the Federal Energy Regulatory Commission (the
         "FERC") thereunder or (b) the securities or blue sky laws of the
         various states in connection with the offer and sale of the Shares;

               (v)  such counsel is of the opinion that the Registration
         Statement and the Prospectus (except for the financial statements and
         other financial and statistical information included therein, as to
         which such counsel does not express any opinion) comply as to form in
         all material respects with the requirements of the Securities Act of
         1933 and the rules and regulations of the Commission thereunder.  In
         passing upon the form of the Registration Statement and Prospectus,
         such counsel has necessarily assumed the correctness and completeness
         of the statements made therein and take no responsibility therefor,
         except so far as the statements relate to such counsel and except that
         such counsel is of the opinion that (i) the statements in the
         Prospectus under the caption
<PAGE>   22
                                                                              22

         "Description of Common Stock", insofar as such statements constitute a
         summary of the documents referred to therein, fairly present the
         information called for with respect to such documents and (ii) the
         statements contained in the Corporation's Annual Report on Form 10-K
         for the year ended 1994 under the caption "Business--Public Utility
         Holding company Act", insofar as they relate to the regulation and
         status of the Company and its subsidiary companies under the Public
         Utility Holding Company Act of 1935, are correct as to matters of law
         and legal conclusions.  In addition, we neither represent nor are
         consulted by the Corporation with respect to the FERC and, in making
         the statement set forth below in this paragraph, to the extent such
         statement refers to such matters, rely solely on the opinion of an
         officer of the Company delivered contemporaneously herewith.  However,
         in the course of the preparation by the Company of the Registration
         Statement and the Prospectus (the documents incorporated therein by
         reference having previously been filed by the Company), such counsel
         participated in conferences with officers of the Company with respect
         thereto, and such counsel's examination of the Registration Statement
         and the Prospectus and such counsel's discussions in the
         above-mentioned conferences did not disclose any information which
         gave such counsel reason to believe that the Registration Statement
         (except for the financial statements and other financial data
         contained therein, as to which such counsel does not express any
         opinion), as of its effective date, contained any untrue statement of
         a material fact or omitted to state any material fact required to be
         stated therein or necessary to make the statements therein not
         misleading, or that the Prospectus (except for the financial
         statements and other financial data contained therein, as to which
         such counsel does not express any opinion), at the date of the
         Prospectus Supplement, included any untrue statement of a material
         fact or omitted to state any material fact necessary in order to make
         the statements therein, in the light of the circumstances under which
         they were made, not misleading; and

               (vi)  the Registration Statement is effective under the
         Securities Act of 1933 and to the best of such counsel's knowledge, no
         proceeding for a stop order with respect thereto is pending or
         threatened under Section 8(d) of the Securities Act of 1933.
<PAGE>   23
                                                                       EXHIBIT C


               Form of Opinion of Special Counsel to the Company


         The opinion of ___________________, counsel to the Company, to be
delivered pursuant to Section 5(b) of the document entitled The Columbia Gas
System, Inc., Underwriting Agreement Standard Provisions (Preferred Stock)
shall be to the effect that:

               (i)  the Company has been duly incorporated, is validly existing
         as a corporation in good standing under the laws of the State of
         Delaware and has due corporate authority to carry on the business in
         which it is engaged;

               (ii)  the Securities have been duly authorized, and when issued
         and delivered to and paid for by the Underwriters in accordance with
         the terms of the Underwriting Agreement, will have been validly issued
         and will be fully paid and nonassessable, and the issuance of the
         Securities is not subject to any preemptive or similar rights;

               (iii)  the Underwriting Agreement has been duly authorized,
         executed and delivered by the Company and is a valid and binding
         agreement of the Company, except as rights to indemnity thereunder may
         be limited by applicable law;

               (iv)  the performance of the Underwriting Agreement will not
         contravene any provision of applicable law or regulation or the
         certificate of incorporation or by-laws of the Company and no consent,
         approval or authorization of any governmental body or agency is
         required for the performance by the Company of its obligations under
         the Underwriting Agreement, except that Counsel does not express any
         opinion with respect to such consent, approval or authorization as may
         be required under (a) the Natural Gas Act, as amended, or the Natural
         Gas Policy Act or the rules, regulations, orders or official
         pronouncements of the Federal Energy Regulatory Commission (the
         "FERC") thereunder or (b) the securities or blue sky laws of the
         various states in connection with the offer and sale of the Shares;

               (v)  such counsel is of the opinion that the Registration
         Statement and the Prospectus (except the financial statements and
         other financial and statistical information included therein, as to
         which such counsel does not express any opinion) comply as to form in
         all material respects with the requirements of the Securities Act of
         1933 and the rules and regulations of the Commission thereunder.  In
         passing upon the form of the Registration Statement and Prospectus,
         such counsel has necessarily assumed the correctness and completeness
         of the statements made therein and take no responsibility therefor,
<PAGE>   24
                                                                              24

         except so far as the statements relate to such counsel and except that
         such counsel is of the opinion that (i) the statements in the
         Prospectus under the caption "Description of Preferred Stock", insofar
         as such statements constitute a summary of the documents referred to
         therein, fairly present the information called for with respect to
         such documents and (ii) the statements contained in the Corporation's
         Annual Report on Form 10-K for the year ended 1994 under the caption
         "Business--Public Utility Holding Company Act", insofar as they relate
         to the regulation and status of the Company and its subsidiary
         companies under the Public Utility Holding Company Act of 1935, are
         correct as to matters of law and legal conclusions.  In addition, we
         neither represent nor are consulted by the Corporation with respect to
         the FERC and, in making the statement set forth below in this
         paragraph, to the extent such statement refers to such matters, rely
         solely on the opinion of [an officer] of the Company delivered
         contemporaneously herewith.  However, in the course of the preparation
         by the Company of the Registration Statement and the Prospectus (the
         documents incorporated therein by reference having previously been
         filed by the Company), such counsel participated in conferences with
         officers of the Company with respect thereto, and such counsel's
         examination of the Registration Statement and the Prospectus and such
         counsel's discussions in the above-mentioned conferences did not
         disclose any information which gave such counsel reason to believe
         that the Registration Statement (except for the financial statements
         and other financial data contained therein, as to which such counsel
         does not express any opinion), as of its effective date, contained any
         untrue statement of a material fact or omitted to state any material
         fact required to be stated therein or necessary to make the statements
         therein not misleading, or that the Prospectus (except for the
         financial statements and other financial data contained therein, as to
         which such counsel does not express any opinion), at the date of the
         Prospectus Supplement, included any untrue statement of a material
         fact or omitted to state any material fact necessary in order to make
         the statements therein, in the light of the circumstances under which
         they were made, not misleading; and

               (vi)  the Registration Statement is effective under the 
         Securities Act of 1933 and to the best of such counsel's knowledge, 
         no proceeding for a stop order with respect thereto is pending or 
         threatened under Section 8(d) of the Securities Act of 1933.
<PAGE>   25
                                                                              25


                                   SCHEDULE I


Underwriting Agreement dated

Registration Statement No.

Representative(s):


Title, Purchase Price and Description of Securities:

         Title:

         Principal amount:

         Purchase price (include accrued
           interest or amortization, if
           any):

         Sinking fund provisions:

         Redemption provisions:

         Other provisions:

Closing Date, Time and Location:

Type of Offering:  [Delayed Offering or Non-Delayed Offering]

Delayed Delivery Arrangements:

         Fee:

         Minimum principal amount of each contract:  $

         Maximum aggregate principal amount of all contracts:  $

         Account referred to in Section 3:
<PAGE>   26
                                                                              26



                                  SCHEDULE II


<TABLE>
<S>                                                        <C>
Underwriters                                               Principal Amount
- ------------                                               of Securities to
                                                              be Purchased   
                                                           ----------------
                                                                             
                                                           $
                                                            





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

Total.................................                     $                   
                                                           ====================
</TABLE>
<PAGE>   27
                                                                              27




                                  SCHEDULE III



                           Delayed Delivery Contract


                                                                            , 19


[Insert name and address
  of lead Representative]


Dear Sirs:

         The undersigned hereby agrees to purchase from 
                 Corporation (the "Company"), and the Company agrees to sell 
to the undersigned, on         , 19  , (the "Delivery Date"), $       principal 
amount of the Company's                   (the "Securities") offered by the
Company's Prospectus dated          , 19  , and related Prospectus Supplement 
dated          , 19  , receipt of a copy of which is hereby acknowledged, at
a purchase price of    % of the principal amount thereof, plus [accrued 
interest] [amortization of original issue discount], if any, thereon from 
          , 19  , to the date of payment and delivery, and on the further 
terms and conditions set forth in this contract.

         Payment for the Securities to be purchased by the undersigned shall be
made on or before 11:00 AM, New York City time, on the Delivery Date to or upon
the order of the Company in Federal Same Day Funds, by wire transfer to the
Account specified in Schedule I of the Underwriting Agreement at [          ]
bank and the undersigned, upon delivery to the undersigned of the Securities in
definitive fully registered form and in such authorized denominations and
registered in such names as the undersigned may request by written or
telegraphic communication addressed to the Company not less than five full
business days prior to the Delivery Date, unless delivered through the DTC book
entry system.  If no request is received, the Securities will be registered in
the name of the undersigned or Cede & Co., as applicable, and issued in a
denomination equal to the aggregate principal amount of Securities to be
purchased by the undersigned on the Delivery Date.

         The obligation of the undersigned to take delivery of, if any, and
make payment for Securities on the Delivery Date, and the obligation of the
Company to sell and deliver
<PAGE>   28
                                                                              28

Securities on the Delivery Date, shall be subject to the conditions (and
neither party shall incur any liability by reason of the failure thereof) that
(1) the purchase of Securities to be made by the undersigned, which purchase
the undersigned represents is not prohibited on the date hereof, shall not on
the Delivery Date be prohibited under the laws of the jurisdiction to which the
undersigned is subject, and (2) the Company, on or before the Delivery Date,
shall have sold to certain underwriters (the "Underwriters") such principal
amount of the Securities as is to be sold to them pursuant to the Underwriting
Agreement referred to in the Prospectus and Prospectus Supplement mentioned
above.  Promptly after completion of such sale to the Underwriters, the Company
will mail or deliver to the undersigned at its address set forth below notice
to such effect, accompanied by a copy of the opinion of counsel for the Company
delivered to the Underwriters in connection therewith.  The obligation of the
undersigned to take delivery of and make payment for the Securities, and the
obligation of the Company to cause the Securities to be sold and delivered,
shall not be affected by the failure of any purchaser to take delivery of and
make payment for the Securities pursuant to other contracts similar to this
contract.

         This contract will inure to the benefit of and be binding upon the
parties hereto and their respective successors, but will not be assignable by
either party hereto without the written consent of the other.

         It is understood that acceptance of this contract and other similar
contracts is in the Company's sole discretion and, without limiting the
foregoing, need not be on a first come, first served basis.  If this contract
is acceptable to the Company, it is required that the Company sign the form of
acceptance below and mail or deliver one of the counterparts hereof to the
undersigned at its address set forth below.  This will become a binding
contract between the Company and the undersigned, as of the date first above
written, when such counterpart is so mailed or delivered.
<PAGE>   29
                                                                              29


         This agreement shall be governed by and construed in accordance with 
the laws of the State of New York.


                                  Very truly yours,
                                  
                                  
                                  
                                  By:  
                                      --------------------------------------
                                           (Name of Purchaser)
                                  
                                  
                                  
                                  By:         
                                       -------------------------------------
                                           (Signature and Title of Officer)
                                  
                                  
                                  
                                  By:          
                                       -------------------------------------
                                           (Address)

Accepted:

Corporation,


By:                                         
     ---------------------------
       (Authorized Signature)

<PAGE>   1

                                                                    EXHIBIT 4-S

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





                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                          MARINE MIDLAND BANK, TRUSTEE






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







                                   INDENTURE

                         Dated as of November 28, 1995





================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                          Indenture Section 
- -----------                                                                          ------------------
<S>                                                                                    <C>
310 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (a)(4)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
311 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
312 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
313 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
314 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
    (c)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
    (c)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
    (f)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
315 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
316 (a)(1)(A)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
    (a)(1)(B)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
317 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
318 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>
<PAGE>   3
                              TABLE OF CONTENTS(1)


<TABLE>
<S>                                                                                                            <C>
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
                                                                                                            
ARTICLE 1                                                                                                   
                                                                                                            
Definitions and Incorporation by Reference                                                                  
         SECTION 1.01.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
         SECTION 1.02.  Other Definitions.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 1.03.  Incorporation by Reference of Trust Indenture Act.    . . . . . . . . . . . . . . . . . 6
         SECTION 1.04.  Rules of Construction.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
                                                                                                            
ARTICLE 2                                                                                                   
                                                                                                            
The Securities                                                                                              
         SECTION 2.01.  Amount; Issuable in Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         SECTION 2.02.  Denominations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
         SECTION 2.03.  Execution, Authentication and Delivery  . . . . . . . . . . . . . . . . . . . . . . . . 9
         SECTION 2.04.  Temporary Securities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
         SECTION 2.05.  Registrar and Paying Agent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
         SECTION 2.06.  Paying Agent To Hold Money in Trust . . . . . . . . . . . . . . . . . . . . . . . . .  11
         SECTION 2.07.  Securityholder Lists  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11
         SECTION 2.08.  Transfer and Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11
         SECTION 2.09.  Replacement Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
         SECTION 2.10.  Outstanding Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
         SECTION 2.11.  Cancellation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         SECTION 2.12.  Default Interest  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
                                                                                                            
ARTICLE 3                                                                                                   
                                                                                                            
Covenants                                                                                                   
         SECTION 3.01.  Payment of Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         SECTION 3.02.  SEC Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         SECTION 3.03.  Limitation on Secured Debt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         SECTION 3.04.  Limitations on Funded Debt or Preferred Stock of Significant Subsidiaries . . . . . .  15
         SECTION 3.05.  Compliance Certificate  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
                                                                                                            
ARTICLE 4                                                                                                   
                                                                                                            
Successor Company                                                                                           
         SECTION 4.01.  When Company May Merge or Transfer Assets . . . . . . . . . . . . . . . . . . . . . .  17
         SECTION 4.02.  Successor Entity Substituted  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
</TABLE>





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

    (1)   The Table of Contents is included herein for convenience only and is
          not to be considered a part of the Indenture.
<PAGE>   4

<TABLE>
<S>                                                                                                                <C>
ARTICLE 5                                                                                                   
                                                                                                            
Defaults and Remedies                                                                                       
         SECTION 5.01.  Events of Default.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
         SECTION 5.02.  Acceleration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         SECTION 5.03.  Other Remedies  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         SECTION 5.04.  Waiver of Past Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         SECTION 5.05.  Control by Majority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         SECTION 5.06.  Limitation on Suits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         SECTION 5.07.  Rights of Holders To Receive Payment. . . . . . . . . . . . . . . . . . . . . . . . . . .  20
         SECTION 5.08.  Collection Suit by Trustee  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
         SECTION 5.09.  Trustee May File Proofs of Claim  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
         SECTION 5.10.  Priorities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
         SECTION 5.11.  Undertaking for Costs.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
         SECTION 5.12.  Waiver of Stay or Extension Laws  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
                                                                                                            
ARTICLE 6                                                                                                   
                                                                                                            
Trustee                                                                                                     
         SECTION 6.01.  Duties of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
         SECTION 6.02.  Rights of Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
         SECTION 6.03.  Individual Rights of Trustee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
         SECTION 6.04.  Trustee's Disclaimer  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         SECTION 6.05.  Notice of Defaults  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         SECTION 6.06.  Reports by Trustee to Holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         SECTION 6.07.  Compensation and Indemnity  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         SECTION 6.08.  Replacement of Trustee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  24
         SECTION 6.09.  Successor Trustee by Merger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  24
         SECTION 6.10.  Eligibility; Disqualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25
         SECTION 6.11.  Preferential Collection of Claims Against Company . . . . . . . . . . . . . . . . . . . .  25
                                                                                                            
ARTICLE 7                                                                                                   
                                                                                                            
Discharge of Indenture; Defeasance                                                                          
         SECTION 7.01.  Discharge of Liability on Securities; Defeasance  . . . . . . . . . . . . . . . . . . . .  25
         SECTION 7.02.  Conditions to Defeasance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25
         SECTION 7.03.  Application of Trust Money  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
         SECTION 7.04.  Repayment to Company  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
                                                                                                            
ARTICLE 8                                                                                                   
                                                                                                            
Amendments                                                                                                  
         SECTION 8.01.  Without Consent of Holders  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27
         SECTION 8.02.  With Consent of Holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27
         SECTION 8.03.  Compliance with Trust Indenture Act . . . . . . . . . . . . . . . . . . . . . . . . . . .  28
         SECTION 8.04.  Revocation and Effect of Consents and Waivers . . . . . . . . . . . . . . . . . . . . . .  28
         SECTION 8.05.  Notation on or Exchange of Securities . . . . . . . . . . . . . . . . . . . . . . . . . .  28
         SECTION 8.06.  Trustee To Sign Amendments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
</TABLE>
<PAGE>   5

<TABLE>
<S>                                                                                                                <C>
ARTICLE 9                                                                                                       
                                                                                                                
Redemption                                                                                                      
         SECTION 9.01.  Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
         SECTION 9.02.  Notice to Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
         SECTION 9.03.  Selection of Securities To Be Redeemed.   . . . . . . . . . . . . . . . . . . . . . . . .  29
         SECTION 9.04.  Notice of Redemption  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30
         SECTION 9.05.  Effect of Notice of Redemption  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30
         SECTION 9.06.  Deposit of Redemption Price . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30
         SECTION 9.07.  Securities Redeemed in Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30
                                                                                                                
ARTICLE 10                                                                                                      
                                                                                                                
Sinking Funds                                                                                                   
         SECTION 10.01.  Applicability  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  31
         SECTION 10.02.  Satisfaction of Sinking Fund Payments with Securities. . . . . . . . . . . . . . . . . .  31
         SECTION 10.03.  Redemption of Securities for Sinking Fund  . . . . . . . . . . . . . . . . . . . . . . .  31
                                                                                                                
ARTICLE 11                                                                                                      
                                                                                                                
Miscellaneous                                                                                                   
         SECTION 11.01.  Trust Indenture Act Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32
         SECTION 11.02.  Notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32
         SECTION 11.03.  Communication by Holders with Other Holders  . . . . . . . . . . . . . . . . . . . . . .  32
         SECTION 11.04.  Certificate and Opinion as to Conditions Precedent . . . . . . . . . . . . . . . . . . .  32
         SECTION 11.05.  Statements Required in Certificate or Opinion. . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.06.  When Securities Disregarded  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.07.  Rules by Trustee, Paying Agent and Registrar . . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.08.  Legal Holidays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.09.  Governing Law  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.10.  No Recourse Against Others.    . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.11.  Successors.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         SECTION 11.12.  Multiple Originals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  34
         SECTION 11.13.  Table of Contents; Headings  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  34
                                                                                                                
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  34
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  34
         ACKNOWLEDGMENT 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  35
         ACKNOWLEDGMENT 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
</TABLE>
<PAGE>   6
         THIS INDENTURE dated as of November 28, 1995 between The Columbia Gas
System, Inc., a corporation duly organized and existing under the laws of the
State of Delaware (hereinafter called the "Company"), having its principal
office at 20 Montchanin Road, Wilmington, Delaware 19807-0020, and Marine
Midland Bank, a banking corporation and trust company organized and existing
under the laws of the State of New York (hereinafter called the "Trustee").

                            RECITALS OF THE COMPANY

         The Company has duly authorized the creation of an issue of its
Securities (hereinafter called the "Securities") of substantially the tenor and
amount hereinafter set forth, and to provide therefor the Company has duly
authorized the execution and delivery of this Indenture.

         All things necessary to make the Securities, when executed by the
Company and authenticated and delivered by the Trustee hereunder and duly
issued by the Company, the valid obligations of the Company, and to make this
Indenture a valid agreement of the Company, in accordance with their and its
terms, have been done.

         NOW, THEREFORE, THIS INDENTURE WITNESSETH:

         For and in consideration of the premises and the purchase of the
Securities by the holders thereof, it is mutually covenanted and agreed, for
the equal and proportionate benefit of all holders of the Securities as
follows:

                                   ARTICLE 1
                   DEFINITIONS AND INCORPORATION BY REFERENCE

         SECTION 1.01.  Definitions.

         "Affiliate" of any specified person means any other person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified person.  For the purposes of this definition,
"control" when used with respect to any specified person means the power to
direct the management and policies of such person directly or indirectly,
whether through the ownership of voting securities, by contract or otherwise;
and the terms "controlling" and "controlled" have meanings correlative to the
foregoing.

         "Board of Directors" means the Board of Directors of the Company or
any committee thereof duly authorized to act on behalf of such Board of
Directors in respect hereof.

         "Board Resolution" means a resolution duly adopted by the Board of
Directors of the Company, a copy of which shall be certified by the Secretary
or an Assistant Secretary, as being in full force and effect on the date of
such certification and delivered to the Trustee.

         "Business Day" means each day which is not a Legal Holiday.

         "Bylaws" means the "Bylaws of The Columbia Gas System, Inc." as
amended from time to time.

         "Capital Lease Obligations" of a person means any obligation which is
required to be classified and accounted for as a capital lease obligation on
the balance sheet of such person prepared in accordance with generally accepted
accounting principles; the amount of such obligation shall be the capitalized
amount thereof, determined in accordance with generally accepted accounting
principles; and the stated maturity thereof shall be the date of the last
payment of rent or any other amount due under such lease





                                       1
<PAGE>   7
prior to the first date upon which such lease may be terminated by the lessee
without payment of a penalty.

         "Capital Stock" means any and all shares, interests, rights to
purchase, warrants, options, participations or other equivalents of or
interests in (however designated) corporate stock, including any Preferred
Stock.

         "Company" means The Columbia Gas System, Inc., a Delaware corporation,
unless and until a successor replaces it pursuant to Article 4 and, thereafter,
means the successor (or any subsequent successor pursuant to said Article) and,
for purposes of any provision contained herein and required by the TIA, each
other Obligor on the Securities.

         "Company Request", "Request of the Company", "Company Order" or "Order
of the Company" means a written request or order signed in the name of the
Company by its Chairman of the Board, its President or a Vice President, and by
its Treasurer, an Assistant Treasurer, its Controller, an Assistant Controller,
its Secretary or an Assistant Secretary, and delivered to the Trustee.

         "Debt" of any person means, without duplication,

                 (i)  the principal of and premium, if applicable, in respect
         of (a) indebtedness of such person for money borrowed and (b)
         indebtedness evidenced by notes, debentures, bonds or other similar
         instruments for the payment of which such person is responsible or
         liable;

                 (ii)  all Capital Lease Obligations of such person;

                 (iii)  all obligations of such person issued or assumed as the
         deferred purchase price of property (but excluding trade accounts
         payable arising in the ordinary course of business);

                 (iv)  all obligations of such person for the reimbursement of
         any obligor on any letter of credit, banker's acceptance or similar
         credit transaction (other than obligations with respect to letters of
         credit securing obligations (other than obligations described in (i)
         through (iii) above) entered into in the ordinary course of business
         of such person to the extent such letters of credit are not drawn upon
         or, if and to the extent drawn upon, such drawing is reimbursed no
         later than the third Business Day following receipt by such person of
         a demand for reimbursement following payment on the letter of credit);

                 (v)  all obligations of the type referred to in clauses (i)
         through (iv) of other persons for the payment of which such person is
         responsible or liable as obligor or guarantor; and

                 (vi)  all obligations of the type referred to in clauses (i)
         through (v) of other persons secured by any Lien on any asset of such
         person (whether or not such obligation is assumed by such person), the
         amount of any such obligation which is not assumed being deemed to be
         the lesser of the amortized cost of such assets or the amount of the
         obligation so secured.

         "Default" means any event which is, or after notice or passage of time
or both would be, an Event of Default as more fully described in Section 5.01
of this Indenture.

         "Depository" means, with respect to the Securities of any series
issuable or issued in whole or in part in the form of one or more Global
Securities, the person designated as Depository by the Company pursuant to
Section 2.01 until a successor Depository shall have become such pursuant to
the applicable provisions of this Indenture, and thereafter "Depository" shall
mean or include each person who is then a Depository hereunder, and if at any
time there is more than one such person, "Depository" as used with





                                       2
<PAGE>   8
respect to the Securities of any such series shall mean the Depository with
respect to the Securities of that series.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended.

         "Funded Debt" means all Debt created, assumed or guaranteed by a
Significant Subsidiary which matures by its terms, or is renewable at the
option of such Subsidiary to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by such Subsidiary.

         "Global Security" means with respect to any series of Securities
issued hereunder, a Security which is executed by the Company and authenticated
and delivered by the Trustee to the Depository or pursuant to the Depository's
instruction, all in accordance with this Indenture, an indenture supplemental
hereto, if any, or Board Resolution and pursuant to a Company Order, which
shall be registered in the name of the Depository or its nominee and which
shall represent, and shall be denominated in an amount equal to the aggregate
Principal Amount of, all of the outstanding Securities of such series or any
portion thereof, in either case having the same Terms, including, without
limitation, the same issue date, date or dates on which principal is due, and
interest rate or method of determining interest.

         "Holder" or "Securityholder" means the person in whose name a Security
is registered on the Registrar's books.

         "Indenture" means this Indenture as amended or supplemented from time
to time.

         "Interest Payment Date" means the date specified in the Securities as
the fixed date on which interest is due and payable.

         "Issue" or "issue" means, with respect to Debt, issue, assume,
guarantee, incur or otherwise become liable for.

         "Lien" means any mortgage, pledge, deposit for security, security
interest or other similar lien, other than the following: (i) liens for taxes
or assessments or other local, state or federal governmental charges or levies;
(ii) any lien to secure obligations under workmen's compensation or
unemployment insurance laws or similar legislation; (iii) any lien to secure
performance in connection with bids, tenders, contracts (other than contracts
for the payment of Debt) or leases (other than Capital Lease Obligations) made
in the ordinary course of business by the Company or any Affiliate thereof;
(iv) liens to secure public or statutory obligations; (v) materialmen's,
mechanics', carriers', workmen's, repairmen's, construction, or other liens or
charges arising in the ordinary course of business; or deposits to obtain the
release of such liens; (vi) any lien to secure indemnity, performance, surety
or similar bonds to which the Company or any Affiliate of the Company is a
party; (vii) liens created by or resulting from court or administrative
proceedings which are currently being contested in good faith by appropriate
actions or proceedings or for the purpose of obtaining a stay or discharge in
the course of any court or legal proceedings for which appropriate accounting
reserves have been made to the extent required by generally accepted accounting
principles; (viii) leases (other than Capital Lease Obligations) made, or
existing on property acquired, constructed or improved, in the ordinary course
of business, together with repairs and additions thereto and improvements
thereof; (ix) landlords' liens; (x) zoning restrictions, easements, licenses,
reservations or restrictions in respect of currently owned or hereafter
acquired, constructed, or improved tangible property or defects or
irregularities (including any terms, conditions, agreements, covenants,
exceptions and reservations expressed or provided in deeds or other agreements)
in title thereto, which do not materially impair the conduct of the business of
the Company; (xi) any of such liens described in clauses (i) through (x),
whether or not delinquent, whose validity or applicability is at the time being
contested in good faith by appropriate actions or proceedings of the Company or
any Subsidiary and for which appropriate accounting reserves have been made to
the extent required by





                                       3
<PAGE>   9
generally accepted accounting principles; (xii) liens securing obligations
neither assumed by the Company or any Subsidiary nor on account of which any of
them customarily pays interest directly or indirectly, existing, either at the
date hereof, or, as to property hereafter acquired, constructed, or improved at
the time of acquisition construction or improvement by the Company or a
Subsidiary; (xiii) any right which any municipal or governmental body or agency
may have by virtue of any franchise, license, contract or statute to purchase,
or designate a purchaser of or order the sale of, any property of the Company
or any Subsidiary upon payment of reasonable compensation therefor, or to
terminate any franchise, license or other rights or to regulate the property
and business of the Company or any Subsidiary; (xiv) the lien of judgments
covered by insurance, or upon appeal and covered, if necessary, by the filing
of an appeal bond, or if not so covered, not exceeding at any one time
$10,000,000 in aggregate amount; (xv) any lien or encumbrance, moneys
sufficient for the discharge of which have been deposited in trust with the
Trustee hereunder or with the trustee or mortgagee under the instrument
evidencing such lien or encumbrance, with irrevocable authority to the Trustee
hereunder or to such other trustee or mortgagee to apply such moneys to the
discharge of such lien or encumbrance to the extent required for such purpose;
(xvi) rights reserved to or vested in others to take or receive any part of the
gas, by-products of gas or steam or electricity generated or produced by or
from any properties of the Company or any Subsidiary or with respect to any
other rights concerning supply, transportation, or storage of a commodity which
is used in the ordinary course of business; and (xvii) liens created or assumed
by the Company or a Subsidiary in connection with the issuance of debt
securities, the interest on which is excludable from the gross income of the
holders of such securities pursuant to Section 103 of the Internal Revenue Code
of 1986, or any successor section.

         "Officer" means the Chairman of the Board, the President, any Vice
President, the Treasurer, the Secretary, the Controller, any Assistant
Treasurer, any Assistant Secretary, any Assistant Controller, or any officers
of the Company designated by Board Resolution or the Bylaws.

         "Officers' Certificate" means a certificate signed by two Officers.

         "Opinion of Counsel" means a written opinion from legal counsel who
may be an employee of or counsel to the Company (or any subsidiary or
affiliate) or other counsel acceptable to the Trustee.

         "Original Issue Discount Security" means any Security which provides
for an amount less than the principal amount thereof to be due and payable upon
a declaration of acceleration of the maturity thereof pursuant to Section 5.02.

         "Preferred Stock" as applied to the capital stock of any corporation,
means stock of any class or classes (however designated) (a) which is preferred
as to the payment of dividends, or as to the distribution of assets on any
voluntary or involuntary liquidation or dissolution of such corporation, over
shares of any other stock of any class of such corporation or (b) which
contains provisions requiring the mandatory redemption of such stock or the
mandatory payment of dividends thereon or which permit the holders of such
stock to put such stock to the issuer thereof.

         "Principal Amount" of a Debt or other obligation means the principal
amount of the same plus the premium, if applicable, payable on the same which
is due or overdue or is to become due at the relevant time.

         "Production Payment" means any economic interest in oil, gas or
mineral reserves which generally entitles the holder thereof to a specified
share of future production from such reserves, free of the costs and expenses
of such production, and terminates when a specified quantity of such share of
future production from such reserves has been delivered or a specified sum has
been realized from the sale of such share of future production from such
reserves or any similar arrangement commonly referred to as a "production
payment".





                                       4
<PAGE>   10
         "SEC" means the United States Securities and Exchange Commission.

         "Secured Debt" means Debt secured by a Lien.

         "Securities" means the Securities issued under this Indenture.

         "Significant Subsidiary" means a Subsidiary that meets the conditions
for being classified as a "significant subsidiary" under Regulation S-X of the
SEC.

         "Subsidiary" means a corporation or limited liability company of which
a majority of the Capital Stock, having voting power under ordinary
circumstances to elect directors, is owned by the Company and/or one or more
Subsidiaries of the Company.

         "Terms" means the maturity date, interest rate or method of
determining the interest rate, interest payment dates, redemption provisions
(optional or mandatory) and any other terms of any Securities established
pursuant to Sections 2.01 and 2.03.

         "TIA" means the Trust Indenture Act of 1939, as amended by the Trust
Indenture Reform Act of 1990 (15 U.S.C.  Section Section 77aaa-77bbbb), as in
effect on the date of this Indenture.

         "Trustee" means the party named as such in this Indenture until a
successor replaces it and, thereafter, means the successor.

         "Trust Officer" means any officer of the Trustee assigned by the
Trustee to administer its corporate trust matters.

         "U.S. Government Obligations" means direct obligations (or
certificates representing an ownership interest in such obligations) of the
United States of America (including any agency or instrumentality thereof) for
the payment of which the full faith and credit of the United States of America
is pledged and which are not callable at the issuer's option.

SECTION 1.02.  Other Definitions.

<TABLE>
<CAPTION>
                                                                                                DEFINED IN
                               TERM                                                              SECTION
                               ----                                                              -------
<S>                                                                                                 <C>
"Bankruptcy Law"                                                                                     5.01
"Consolidated Net Tangible Assets"                                                                   3.03
"Covenant Defeasance Option"                                                                         7.01(b)
"Custodian"                                                                                          5.01
"Event of Default"                                                                                   5.01
"Legal Defeasance Option"                                                                            7.01(b)
"Legal Holiday"                                                                                     11.08
"Mandatory Sinking Fund Payment"                                                                    10.01
"Notice of Default"                                                                                  5.01
"Optional Sinking Fund Payment"                                                                     10.01
"Paying Agent"                                                                                       2.05
"Registrar"                                                                                          2.05
"Net Tangible Assets"                                                                                3.03
</TABLE>

         SECTION 1.03.  Incorporation by Reference of Trust Indenture Act.
Whenever this Indenture refers to a provision of the TIA or a provision of the
TIA provides that an indenture to be qualified





                                       5
<PAGE>   11
thereunder shall be deemed to include such provision, the provision is
incorporated by reference in and made a part of this Indenture as if fully set
forth herein and in any supplements hereto.  The following TIA terms used in
this Indenture have the following meanings:

         "Commission" means the SEC.

         "Obligor" on the Securities means the Company and any other obligor on
the Securities.

         All other TIA terms used in this Indenture that are defined by the
TIA, defined by TIA reference to another statute or defined by Commission rule
have the meanings assigned to them by such definitions.

         SECTION 1.04.  Rules of Construction.  Unless the context otherwise
requires:

                 (1)  a term has the meaning assigned to it;

                 (2)  an accounting term not otherwise defined has the meaning
         assigned to it in accordance with generally accepted accounting
         principles as in effect from time to time;

                 (3)  "including" means including, without limitation;

                 (4)  "person" means any individual, corporation, partnership,
         joint venture, association, joint-stock company, trust, unincorporated
         organization, government or any agency or political subdivision
         thereof or any other entity.

                 (5)  "or" is not exclusive;

                 (6)  words in the singular include the plural and words in the
         plural include the singular; and

                 (7)  the principal amount of any noninterest bearing or other
         discount security at any date shall be the principal amount thereof
         that would be shown on a balance sheet of the issuer dated such date
         prepared in accordance with generally accepted accounting principles
         and accretion of principal on such security shall not be deemed to be
         the issuance of Debt.

                                   ARTICLE 2
                                 THE SECURITIES

         SECTION 2.01.  Amount; Issuable in Series.  The aggregate Principal
Amount of Securities which may be authenticated and delivered under this
Indenture is unlimited.

         The Securities may be issued in one or more series and Securities of
the same series may have different Terms.  There shall be established in or
pursuant to a Board Resolution, and set forth in an Officers' Certificate or
established in one or more indentures supplemental hereto, prior to the
issuance of Securities of any series, except as contemplated by the fourth
paragraph of Section 2.03:

                 (1)  the title of the Securities of the series (which shall
         distinguish the Securities of the series from all Securities of other
         series);

                 (2)  any limit upon the aggregate Principal Amount of the
         Securities of the series which may be authenticated and delivered
         under this Indenture (except for Securities authenticated and
         delivered upon registration of transfer of, or in exchange for, or in
         lieu of, other Securities of the series pursuant to Sections 2.04,
         2.08, 2.09, 8.05 and 9.07);





                                       6
<PAGE>   12
                 (3)  the date or dates on which the principal and premium, if
         applicable, of any of the Securities of the series are payable or the
         method of determination thereof;

                 (4)  the rate or rates, or the method of determination
         thereof, at which any of the Securities of the series shall bear
         interest, if any, the date or dates from which such interest shall
         accrue, the Interest Payment Dates on which such interest shall be
         payable and the regular record date for the interest payable on any
         Interest Payment Date;

                 (5)  the place or places where the principal of and interest,
         if any, on any of the Securities of the series shall be payable and
         the office or agency for the Securities of the series maintained by
         the Company pursuant to Section 2.05;

                 (6)  the period or periods within which, the price or prices
         at which and the Terms and conditions upon which any of the Securities
         of the series may be redeemed, in whole or in part, at the option of
         the Company;

                 (7)  the Terms of any sinking fund and the obligation, if any,
         of the Company to redeem or purchase Securities of the series pursuant
         to any sinking fund or analogous provisions or at the option of a
         Holder thereof and the period or periods within which, the price or
         prices at which and the Terms and conditions upon which Securities of
         the series shall be redeemed or purchased, in whole or in part;

                 (8)  if other than denominations authorized by Section 2.02,
         the denominations in which the Securities of the series shall be
         issuable;

                 (9)  if other than the Principal Amount thereof, the portion
         of the Principal Amount of any of the Securities of the series which
         shall be payable upon declaration of acceleration of the maturity
         thereof pursuant to Section 5.02;

                 (10)  any deletions or modifications of or additions to the
         Events of Default set forth in Section 5.01 or covenants of the
         Company set forth in Article 3 pertaining to the Securities of the
         series;

                 (11)  whether the Securities are secured or unsecured
         obligations of the Company;

                 (12)  the forms of the Securities of the series;

                 (13)  whether the Securities of the series shall be issued in
         whole or in part in the form of one or more Global Securities and, in
         such case, the Depository for such Global Security or Securities;

                 (14)  if Securities of the series are to be convertible into
         other securities, the Terms of such conversion; and

                 (15)  any other Terms of any of the Securities of the series.

         All Securities of any one series shall be substantially identical
except as to denomination and except as may otherwise be provided in or
pursuant to the Board Resolution referred to above, or the Company Order
contemplated by the fourth paragraph of Section 2.03, and set forth in the
Officers' Certificate referred to above or in any such indenture supplemental
hereto.





                                       7
<PAGE>   13
         At the option of the Company, interest on any series that bears
interest may be paid by mailing a check to the address of, or making a wire
transfer to the account of, any Holder as such address shall appear in the
register maintained pursuant to Section 2.05.

         The Securities may have notations, legends or endorsements required by
law, stock exchange rule, agreements to which the Company is subject, if any,
or usage (provided that any such notation, legend or endorsement is in a form
acceptable to the Company).

         If any of the Terms of the series are established by action taken
pursuant to a Board Resolution, except as to those contemplated by the fourth
paragraph of Section 2.03, a copy of an appropriate record of such action
together with such Board Resolution shall be certified by the Secretary or an
Assistant Secretary of the Company and delivered to the Trustee at or prior to
the delivery of the Officers' Certificate setting forth the Terms of the
series.

         SECTION 2.02.  Denominations.  The Securities of each series shall be
issuable in such denominations as shall be specified as contemplated by Section
2.01.  In the absence of any such provisions with respect to the Securities of
any series, the Securities of such series shall be issuable in denominations of
$1,000 and in any integral multiple thereof.  Securities of each series shall
be numbered, lettered or otherwise distinguished in such manner in accordance
with such plan as the Officers of the Company executing the same may determine
with the approval of the Trustee.

         SECTION 2.03.  Execution, Authentication and Delivery.  One Officer
shall sign the Securities for the Company by manual or facsimile signature.
The Company's seal shall be impressed, affixed, imprinted or reproduced on the
Securities and may be in facsimile form.

         If an Officer whose signature is on a Security no longer holds that
office at the time the Trustee authenticates the Security, the Security shall
be valid nevertheless.

         A Security shall not be valid until an authorized signatory of the
Trustee manually signs the certificate of authentication on the Security.  The
signature shall be conclusive evidence that the Security has been authenticated
under this Indenture.

         At any time after the execution and delivery of this Indenture, the
Company may execute and deliver to the Trustee Securities of any series,
together with a Company Order for the authentication and delivery of such
Securities, and the Trustee in accordance with the Company Order shall
authenticate and deliver such Securities; provided that, if all Securities of a
series are not to be originally issued at one time, the Trustee shall
authenticate and deliver Securities of such series for original issue from time
to time in the aggregate Principal Amount established for such series pursuant
to such procedures acceptable to the Trustee and to such recipients as may be
specified from time to time by Company Order.  The maturity date, original
issuance date, interest rate and any other Terms of the Securities of such
series shall be determined by or pursuant to such Company Order and procedures.
If provided for in such procedures, such Company Order may authorize
authentication and delivery pursuant to oral or electronic instructions from
the Company or its duly authorized agents, which instructions, if given orally,
shall be promptly confirmed in writing.

         If the forms or Terms of the Securities of the series have been
established by or pursuant to one or more Board Resolutions as permitted by
Section 2.01, in authenticating such Securities, and accepting the additional
responsibilities under this Indenture in relation to such Securities, the
Trustee shall be entitled to receive, and (subject to Section 6.01) shall be
fully protected in relying upon, an Opinion of Counsel stating:





                                       8
<PAGE>   14
                 (a)  that such forms and/or Terms have been established in
         conformity with the provisions of this Indenture; and

                 (b)  that such Securities, when authenticated and delivered by
         the Trustee and issued by the Company in the manner and subject to any
         conditions specified in such Opinion of Counsel, will constitute valid
         and legally binding obligations of the Company, entitled to the
         benefits of the Indenture and enforceable against the Company in
         accordance with their terms, subject to such exceptions as counsel may
         specify.

If such forms or Terms have been so established, the Trustee shall not be
required to authenticate such Securities if the issue of such Securities
pursuant to this Indenture will affect the Trustee's own rights, duties or
immunities under the Securities and this Indenture or otherwise in a manner
which is not reasonably acceptable to the Trustee.

         Notwithstanding the provisions of Section 2.01 and of the preceding
paragraph, if all Securities of a series are not to be originally issued at one
time, it shall not be necessary to deliver the Officers' Certificate otherwise
required pursuant to Section 2.01 or the Company Order and Opinion of Counsel
otherwise required pursuant to such preceding paragraph at or prior to the time
of authentication of each Security of such series if such documents are
delivered at or prior to the authentication upon original issuance of the first
Security of such series to be issued; provided that paragraph (a) of said
Opinion of Counsel shall, in such case, read as follows:

                 "(a)  that such forms have been established in conformity with
         the provisions of this Indenture and the procedures for determining
         the Terms of such Securities as set forth in the procedures
         hereinabove referred to have been established in conformity with the
         provisions of this Indenture."

         If the Company shall establish pursuant to Section 2.01 that the
Securities of a series are to be issued in whole or in part in the form of a
Global Security, then the Company shall execute and the Trustee shall in
accordance with this Section and the Company Order with respect to such series
authenticate and deliver the Global Security that (i) shall represent and shall
be denominated in an aggregate amount equal to the aggregate principal amount
of Outstanding Securities of such series to be represented by the Global
Security, (ii) shall be registered in the name of the Depository or its
nominee, and (iii) shall be delivered by the Trustee to such Depository or
pursuant to such Depository's instruction.

         Each Depository designated pursuant to Section 2.01 for a Global
Security in registered form must, at the time of its designation and at all
times while it serves as Depository, be a clearing agency registered under the
Exchange Act and any other applicable statute or regulation.

         SECTION 2.04.  Temporary Securities.  Pending the preparation of
definitive Securities of any series, the Company may execute, and upon Company
Order the Trustee shall authenticate and deliver, temporary Securities which
are printed, lithographed, typewritten, mimeographed or otherwise produced, in
any authorized denomination, substantially of the tenor of the definitive
Securities in lieu of which they are issued, in registered form and with such
appropriate insertions, omissions, substitutions and other variations as the
Officers executing such Securities may determine, as evidenced conclusively by
their execution of such Securities.  Such temporary Securities may be in global
form.

         If temporary Securities of any series are issued, the Company will
cause definitive Securities of that series to be prepared without unreasonable
delay.  After the preparation of definitive Securities of such series, the
temporary Securities of such series shall be exchangeable for definitive
Securities of such





                                       9
<PAGE>   15
series upon surrender of the temporary Securities of such series at the office
or agency of the Company maintained pursuant to Section 2.05 for the purpose of
exchanges of Securities of such series, without charge to the Holder.  Upon
surrender for cancellation of any one or more temporary Securities of any
series the Company shall execute and the Trustee shall authenticate and deliver
in exchange therefor a like aggregate Principal Amount of definitive Securities
of the same series and of like tenor in authorized denominations and having the
same Terms and conditions.

         Until exchanged in full as hereinabove provided, the temporary
Securities of any series shall in all respects be entitled to the same benefits
under this Indenture as definitive Securities of the same series and of like
tenor authenticated and delivered hereunder.

         SECTION 2.05.  Registrar and Paying Agent.  The Company shall maintain
an office or agency where Securities may be presented for registration of
transfer or for exchange (the "Registrar") and an office or agency where
Securities may be presented for payment (the "Paying Agent").  The Registrar
shall keep a register of the Securities and of their transfer and exchange.
The Company may have one or more co-registrars and one or more additional
paying agents.  The term "Paying Agent" includes any additional paying agent.

         The Company shall enter into an appropriate agency agreement with any
Registrar, Paying Agent or co-registrar not a party to this Indenture, which
shall incorporate the terms of the TIA.  The agreement shall implement the
provisions of this Indenture that relate to such agent.  The Company shall
notify the Trustee of the name and address of any such agent.  If the Company
fails to maintain a Registrar or Paying Agent, the Trustee shall act as such
and shall be entitled to appropriate compensation therefor pursuant to Section
6.07.  The Company or any Subsidiary or Affiliate of the Company may act as
Paying Agent, Registrar, co-registrar or transfer agent.

         The Company initially appoints the Trustee as Registrar and Paying
Agent in connection with the Securities.

         SECTION 2.06.  Paying Agent To Hold Money in Trust.  On or prior to
each due date of the principal and interest on any Security, the Company shall
deposit with the Paying Agent a sum sufficient to pay such principal and
interest when so becoming due.  The Company shall require each Paying Agent
(other than the Trustee) to agree in writing that the Paying Agent shall hold
in trust for the benefit of Securityholders or the Trustee all money held by
the Paying Agent for the payment of principal of or interest on the Securities
and shall notify the Trustee of any default by the Company in making any such
payment.  If the Company or any Subsidiary or Affiliate of the Company acts as
Paying Agent, it shall segregate the money held by it as Paying Agent and hold
it as a separate trust fund.  The Company at any time may require a Paying
Agent to pay all money held by it to the Trustee and to account for any funds
disbursed by the Paying Agent.  Upon complying with this Section, the Paying
Agent shall have no further liability for the money delivered to the Trustee.

         SECTION 2.07.  Securityholder Lists.  The Trustee shall preserve in as
current a form as is reasonably practicable the most recent list available to
it of the names and addresses of Securityholders.  If the Trustee is not the
Registrar, the Company shall furnish to the Trustee, in writing at least five
Business Days before each May 15 and November 15 and at such other times as the
Trustee may request in writing, a list in such form and as of such date as the
Trustee may reasonably require of the names and addresses of Securityholders.

         SECTION 2.08.  Transfer and Exchange.  The Securities shall be issued
in registered form and shall be transferable only upon the surrender of a
Security with similar Terms of the same series for





                                       10
<PAGE>   16
registration of transfer.  When a Security is presented to the Registrar or a
co-registrar with a request to register a transfer, the Registrar shall
register the transfer as requested, subject to compliance with this paragraph.
When Securities of a series are presented to the Registrar or a co-registrar
with a request to exchange them for an equal Principal Amount of Securities of
such series with similar Terms of other denominations, the Registrar shall make
the exchange as requested, subject to such compliance.  To permit registration
of transfers and exchanges, the Company shall execute and the Trustee shall
authenticate Securities of the applicable series with similar Terms at the
Registrar's or co-registrar's request.  The Company may require payment of a
sum sufficient to pay all taxes, assessments or other governmental charges.
Every Security presented or surrendered for registration of transfer or for
exchange shall (if so required by the Company or the Trustee) be duly endorsed,
or be accompanied by a written instrument of transfer in form satisfactory to
the Company and the Registrar duly executed, by the Holder thereof or his
attorney duly authorized in writing.  The Company shall not be required (i) to
Issue, register the transfer of or exchange Securities of any series during a
period beginning at the opening of business 15 days before the day of the
mailing of a notice of redemption of Securities of that series selected for
redemption under Section 9.03 and ending at the close of business on the day of
such mailing, or (ii) to register the transfer of or exchange any Security so
selected for redemption in whole or in part, except the unredeemed portion of
any Security being redeemed in part.

         Prior to the due presentation for registration of transfer of any
Security, the Company, the Trustee, the Paying Agent, the Registrar or any
co-registrar may deem and treat the person in whose name a Security is
registered as the absolute owner of such Security for the purpose of receiving
payment of principal of and interest on such Security and for all other
purposes whatsoever, whether or not such Security is overdue, and none of the
Company, the Trustee, the Paying Agent, the Registrar or any co-registrar shall
be affected by notice to the contrary.

         If at any time the Depository for the whole or part of the Securities
of a series notifies the Company that it is unwilling or unable to continue as
Depository for such Securities or if at any time the Depository for such
Securities shall no longer be eligible under Section 2.01, the Company shall
appoint a successor Depository with respect to such Securities.  If a successor
Depository for such Securities is not appointed by the Company within 90 days
after the Company receives such notice or becomes aware of such ineligibility,
the Company's election pursuant to Section 2.01 shall no longer be effective
with respect to such Securities and the Company will execute, and the Trustee,
upon receipt of a Company Order for the authentication and delivery of
definitive Securities of such series, will authenticate and deliver,
corresponding Securities in definitive form in an aggregate principal amount
equal to the Principal Amount of the Global Security representing such
Securities in exchange for such Global Security.

         If specified by the Company pursuant to Section 2.01 with respect to a
series of Securities, the Company may at any time and in its sole discretion
determine that Securities of any series issued in the form of one or more
Global Securities shall no longer be represented by such Global Security or
Securities.  In such event the Company will execute, and the Trustee, upon
receipt of a Company Order for the authentication and delivery of corresponding
definitive Securities, will authenticate and deliver such Securities in
definitive form and in an aggregate Principal Amount equal to the Principal
Amount of such Global Security or Securities in exchange for such Global
Security or Securities.

         If specified by the Company pursuant to Section 2.01 with respect to
the whole or part of a series of Securities, the Depository for such Securities
may surrender a Global Security for such Securities with similar Terms in
exchange in whole or in part for Securities of such series with similar Terms
in definitive form on such terms as are acceptable to the Company and such
Depository.  Thereupon, the Company shall execute, and the Trustee, upon
receipt of a Company Order for the authentication and delivery of





                                       11
<PAGE>   17
definitive Securities of such series with similar Terms, shall authenticate and
deliver, without charge to the Holders,

                 (i) to each person specified by such Depository a new Security
         or Securities of the series with similar Terms of any authorized
         denomination as requested by such person in aggregate Principal Amount
         equal to and in exchange for such person's beneficial interest in the
         Global Security; and

                 (ii) to such Depository a new Global Security in a
         denomination equal to the difference, if any, between the Principal
         Amount of the surrendered Global Security and the aggregate Principal
         Amount of Securities with similar Terms delivered to Holders thereof.

         In any exchange provided for in any of the preceding three paragraphs,
the Company will execute and the Trustee will authenticate and deliver
Securities in definitive form in authorized denominations.

         Upon the exchange of a Global Security for Securities in definitive
form, such Global Security shall be canceled by the Trustee.  Securities issued
in exchange for a Global Security pursuant to this Section shall be registered
in such names and in such authorized denominations as the Depository for such
Global Security, pursuant to instructions from its direct or indirect
participants or otherwise, shall instruct the Trustee.  The Trustee shall
deliver such Securities to the persons in whose names such Securities are so
registered.

         Notwithstanding any other provision of this Section to the contrary,
unless and until a Global Security is exchanged in whole for Securities in
definitive form, a Global Security representing all or a portion of the
Securities of a series may not be transferred except as a whole by the
Depository for such series to a nominee of such Depository or by a nominee of
such Depository to such Depository or another nominee of such Depository or by
such Depository or any such nominee to a successor Depository for such series
or a nominee of such successor Depository.

         SECTION 2.09.  Replacement Securities.  If a mutilated Security is
surrendered to the Registrar or if the Holder of a Security claims that the
Security has been lost, destroyed or wrongfully taken, the Company shall Issue
and the Trustee shall authenticate a replacement Security of the applicable
series with similar Terms if the Holder satisfies any other reasonable
requirements of the Trustee.  If required by the Trustee or the Company, such
Holder shall furnish evidence to their satisfaction of the destruction, loss or
wrongful taking of any Security so claimed to be lost, destroyed or wrongfully
taken, and an indemnity bond sufficient in the judgment of the Company and the
Trustee to protect the Company, the Trustee, the Paying Agent, the Registrar
and any co-registrar from any loss which any of them may suffer if a Security
is replaced.  The Company and the Trustee may charge the Holder for their
expenses in replacing a Security.

         Every replacement Security is an additional obligation of the Company.

         SECTION 2.10.  Outstanding Securities.  Securities outstanding at any
time are all Securities authenticated by the Trustee except for those canceled
by it, those delivered to it for cancellation and those described in this
Section as not outstanding.  A Security does not cease to be outstanding
because the Company or an Affiliate of the Company holds the Security.

         If a Security is replaced pursuant to Section 2.09, it ceases to be
outstanding unless the Trustee and the Company receive proof satisfactory to
them that the replaced Security is held by a bona fide purchaser.





                                       12
<PAGE>   18
         If the Paying Agent segregates and holds in trust, in accordance with
this Indenture, on a redemption date or maturity date money sufficient to pay
all principal, premium (if applicable) and interest payable on that date with
respect to the Securities to be redeemed or maturing, as the case may be, and
the Paying Agent is not prohibited from paying such money to the
Securityholders on that date pursuant to the terms of this Indenture, then on
and after that date such Securities cease to be outstanding and interest on
them ceases to accrue.

         In determining whether the Holders of the requisite Principal Amount
of outstanding Securities have given any request, demand, authorization,
direction, notice, consent or waiver hereunder, the Principal Amount of an
Original Issue Discount Security that shall be deemed to be outstanding for
such purposes shall be the amount of the principal thereof that would be due
and payable as of the date of such determination upon a declaration of
acceleration of the maturity thereof pursuant to Section 5.02.

         SECTION 2.11.  Cancellation.  The Company at any time may deliver
Securities to the Trustee for cancellation.  The Registrar and the Paying Agent
shall forward to the Trustee any Securities surrendered to them for
registration of transfer, exchange or payment.  The Trustee and no one else
shall cancel and destroy (subject to the record retention requirements of the
Exchange Act) all Securities surrendered for registration of transfer,
exchange, payment or cancellation and deliver a certificate of such destruction
to the Company unless the Company directs the Trustee to deliver canceled
Securities to the Company.  The Company may not Issue new Securities to replace
Securities it has redeemed, paid or delivered to the Trustee for cancellation.

         SECTION 2.12.  Default Interest.  If the Company defaults in a payment
of interest on the Securities, the Company shall pay defaulted interest (plus
interest on such defaulted interest to the extent lawful at the rate or rates
prescribed therefor in the Securities) in any lawful manner.  The Company may
also pay the defaulted interest to the persons who are Securityholders on a
subsequent special record date, which date shall be at least five Business Days
prior to the payment date in which case the Company shall fix or cause to be
fixed any such special record date and payment date, and, at least 15 days
before any such special record date, the Company shall mail to each
Securityholder a notice that states the special record date, the payment date
and the amount of defaulted interest to be paid.

                                   ARTICLE 3
                                   COVENANTS

         SECTION 3.01.  Payment of Securities.  The Company shall promptly pay
the principal of and interest on the Securities on the dates and in the manner
provided in the Securities and in this Indenture.  Principal and interest shall
be considered paid on the date due if on such date the Trustee or the Paying
Agent holds in accordance with this Indenture money sufficient to pay all
principal and interest then due and the Trustee or the Paying Agent, as the
case may be, is not prohibited from paying such money to the Securityholders on
that date pursuant to the terms of this Indenture.

         SECTION 3.02.  SEC Reports.  The Company shall file with the Trustee,
within 30 days after it files them with the SEC, copies of its annual report
and of the information, documents and other reports (or copies of such portions
of any of the foregoing as the SEC may by rules and regulations prescribe)
which the Company is required to file with the SEC pursuant to Section 13 or
15(d) of the Exchange Act.  The Company shall also comply with the other
provisions of TIA Section 314(a)(1), (2) and (3).

         SECTION 3.03.  Limitation on Secured Debt.  The Company shall not
issue any Secured Debt unless contemporaneously therewith effective provision
is made to secure the Securities equally and ratably with such Secured Debt for
so long as such Secured Debt is secured by a Lien.  The preceding





                                       13
<PAGE>   19
sentence shall not require the Company to equally and ratably secure the
Securities upon the incurrence of the following Secured Debt:

                 (1)  Debt of the Company which is incurred to finance the
         acquisition, construction or improvement of assets of the Company and
         its Subsidiaries, which acquisition is consummated, or which
         construction or improvement is commenced, after the date of this
         Indenture; provided, however, that such Debt shall not be secured by
         any assets of the Company other than assets so acquired, constructed
         or improved (together with (i) to the extent the terms of Secured Debt
         so provides, repairs and additions thereto and improvements thereof,
         and (ii) with respect to construction and improvement, any theretofore
         unimproved real property on which the property so constructed or
         improved is located);

                 (2)  Debt of the Company which is secured by assets of a
         person where such Debt was existing at the time such person was merged
         or consolidated with the Company or at the time of sale, other
         disposition, or lease, of the properties of such person as an entirety
         (or substantially as an entirety) to the Company; provided, however,
         that such Debt shall not be secured by any assets of the Company other
         than the assets subject thereto at the time of the acquisition
         (together with, to the extent the terms of Secured Debt so provides,
         repairs and additions thereto and improvements thereof);

                 (3)  Debt of the Company issued to refinance such Debt
         incurred under paragraphs (1) and (2) provided that the Debt so issued
         is not secured by a Lien on assets other than those which secure the
         Debt being refinanced (together with, to the extent the terms of new
         Secured Debt so provides, repairs and additions thereto and
         improvements thereof);

                 (4)  Debt of the Company which is secured by inventory,
         accounts receivable, or customers' installment paper or the proceeds
         thereof, including by means of asset securitization;

                 (5)  Obligations arising with respect to Production Payments;
         and

                 (6)  Other Debt which does not exceed, in an aggregate
         principal amount at any one time outstanding, ten percent (10%) of the
         Consolidated Net Tangible Assets of the Company and its consolidated
         subsidiaries, determined as of the end of the most recent fiscal
         quarter of the Company ending not less than 45 days from the date of
         determination.

                 The term "Consolidated Net Tangible Assets" means the sum of
         the Net Tangible Assets of the Company and its consolidated
         Subsidiaries after eliminating intercompany items.

                 The term "Net Tangible Assets", as applied to any person on
         any date shall mean the gross book value as shown on the books of such
         person of all its property both real and personal (exclusive of
         licenses, patents, patent applications, copyrights, trademarks, trade
         names, good will, experimental or organizational expense and other
         like intangibles, treasury stock and unamortized debt discount and
         expense but including regulatory assets properly recorded on the
         balance sheet of such person), less all reserves for depreciation,
         obsolescence, depletion and amortization of its properties as shown by
         the books of such person and all other proper reserves which in
         accordance with generally accepted accounting principles should be
         provided in connection with the business conducted by such person.





                                       14
<PAGE>   20
         SECTION 3.04.  Limitations on Funded Debt or Preferred Stock of
Significant Subsidiaries.  The Company shall not permit any Significant
Subsidiary to issue, directly or indirectly, any Funded Debt or Preferred Stock
except:

                 (1)  Funded Debt and Preferred Stock issued and outstanding on
         or prior to the date of this Indenture;


                 (2)  Funded Debt and Preferred Stock issued to and held by the
         Company or a Subsidiary; provided, however, that any subsequent
         issuance or transfer of any common stock which results in any such
         Subsidiary ceasing to be a Subsidiary and any subsequent transfer of
         such Debt or Preferred Stock (other than to the Company or a
         Subsidiary) shall be deemed the issuance of such Debt by the issuer
         thereof;

                 (3)  Funded Debt and Preferred Stock of a Significant
         Subsidiary issued and outstanding on or prior to the date on which
         such Subsidiary was acquired by the Company or on which it became a
         Significant Subsidiary;

                 (4)  Funded Debt and Preferred Stock issued to finance the
         acquisition by such Significant Subsidiary of any assets or Capital
         Stock of any person or the construction or improvement of assets of
         such Significant Subsidiary, which acquisition is consummated, or
         which construction or improvement is commenced, after the date of this
         Indenture;

                 (5)  Funded Debt and Preferred Stock issued in exchange for,
         or the proceeds of which are used to refund or refinance, Debt or
         Preferred Stock referred to in the foregoing clauses (1) through (4)
         or to reacquire equity or debt or to repay debt of such Significant
         Subsidiary held by the Company or a Subsidiary;

                 (6)  Funded Debt issued with respect to (a) obligations that
         are tax-exempt pursuant to Section 103 of the Internal Revenue Code of
         1986 as from time to time amended and that are issued in connection
         with pollution control or other facilities of such Significant
         Subsidiary or (b) other obligations, whether taxable to tax-exempt,
         that are issued through any public or governmental authority in
         connection with pollution control or other facilities of such
         Significant Subsidiary;

                 (7)  Funded Debt in an aggregate amount not exceeding the sum
         of (a) total inventory of the Significant Subsidiary; (b) total
         accounts receivable of the Significant Subsidiary; and (c) the total
         amount of customers' installment paper of such Significant Subsidiary,
         determined in accordance with generally accepted accounting
         principles, in each case, as of the end of the most recent fiscal
         quarter of such Significant Subsidiary ending not less than 45 days
         from the date of determination;

                 (8)  Obligations with respect to Production Payments; and

                 (9)  Funded Debt in an aggregate Principal Amount and
         Preferred Stock having an aggregate preferential involuntary
         liquidation value, in either case which, when added to the aggregate
         Principal Amount of Funded Debt of all other Significant Subsidiaries
         (other than Funded Debt referred to in clauses (1) through (8) above)
         and when added to the aggregate preferential involuntary liquidation
         value of Preferred Stock (other than Preferred Stock referred to in
         clauses (1) through (5) above), does not exceed, at any one time
         outstanding, ten percent





                                       15
<PAGE>   21
         (10%) of the sum of the Net Tangible Assets of such Significant
         Subsidiary and all other Significant Subsidiaries determined on a
         consolidated basis, as of the end of the most recent fiscal quarter of
         each such Significant Subsidiary ending not less than 45 days from the
         date of determination.

         SECTION 3.05.  Compliance Certificate.  The Company shall deliver to
the Trustee within 120 days after the end of each fiscal year of the Company a
certificate from its principal executive officer, principal financial officer
or principal accounting officer stating that in the course of the performance
by such signer of his duties as an officer of the Company he would normally
have knowledge of any Default by the Company or any noncompliance with the
conditions and covenants under the Indenture and whether or not he knows of any
Default or any such noncompliance that occurred during such period.  If such
officer does, the certificate shall describe the Default or non-compliance, its
status and what action the Company is taking or proposes to take with respect
thereto.  For purposes of this Section 3.05, such noncompliance shall be
determined without regard to any period of grace or requirement of notice
provided under this Indenture.

                                   ARTICLE 4
                               SUCCESSOR COMPANY

         SECTION 4.01.  When Company May Merge or Transfer Assets.  The Company
shall not consolidate with or merge with or into, or convey or otherwise
transfer, or lease, its assets as an entirety (or substantially as an entirety)
to, any person, unless:

                 (i)  the resulting, surviving or transferee person (if not the
         Company) shall be a person organized and existing under the laws of
         the United States of America, any State thereof or the District of
         Columbia and shall expressly assume, by an indenture supplemental
         hereto, executed and delivered to the Trustee, in form reasonably
         satisfactory to the Trustee, all the obligations of the Company under
         the Securities and this Indenture;

                 (ii)  immediately after giving effect to such transaction no
         Default shall have happened and be continuing; and

                 (iii)  the Company shall have delivered to the Trustee an
         Officers' Certificate and an Opinion of Counsel, each stating that
         such consolidation, merger, transfer, or lease and such supplemental
         indenture (if any) comply with this Indenture.

         SECTION 4.02.  Successor Entity Substituted.  Upon any consolidation
by the Company with or merger by the Company into any other entity or any
conveyance or other transfer, or lease, of the assets of the Company as an
entirety (or substantially as an entirety) in accordance with Section 4.01, the
successor entity formed by such consolidation or into which the Company is
merged or to which such conveyance or other transfer, or lease, is made shall
succeed to, and be substituted for, and may exercise every right and power of,
the Company under this Indenture with the same effect as if such successor
entity had been named as the Company herein, and thereafter, except in the case
of a lease, the predecessor entity shall be relieved of all obligations and
covenants under this Indenture and the Securities.





                                       16
<PAGE>   22
                                   ARTICLE 5
                             DEFAULTS AND REMEDIES

         SECTION 5.01.  Events of Default.  An "Event of Default" occurs if:

         (1)  the Company defaults in any payment of interest on any Security
when the same becomes due and payable and such default continues for a period
of 20 days;

         (2)  the Company defaults in the payment of the principal of any
Security when the same becomes due and payable at its stated maturity, upon
declaration or otherwise;

         (3)  the Company fails to comply with Section 4.01;

         (4)  the Company fails to comply with any of its agreements in the
Securities or this Indenture (other than those referred to in (1), (2), or (3)
above) and such failure continues for 60 days after the notice specified below;

         (5)  the Company has entered against it final, non-appealable court
judgments for the payment of money exceeding in the aggregate $50,000,000 in
uninsured liability and such judgments are not discharged, paid or adequately
provided for within 60 days after the last of such judgments to become final
and non-appealable;

         (6)  the Company pursuant to or within the meaning of any Bankruptcy
Law:

                 (A)  commences a voluntary case;

                 (B)  consents to the entry of an order for relief against it
                 in an involuntary case;

                 (C)  consents to the appointment of a Custodian of it or for
                 any substantial part of its property; or

                 (D)  makes a general assignment for the benefit of its 
                 creditors; or

         (7)  a court of competent jurisdiction enters an order or decree under
any Bankruptcy Law that:

                 (A)  is for relief against the Company in an involuntary case;

                 (B)  appoints a Custodian of the Company or for any
                 substantial part of its property; or

                 (C)  orders the winding up or liquidation of the Company;

and the order or decree remains unstayed and in effect for 60 days.

         The term "Bankruptcy Law" means Title 11, United States Code, or any
similar Federal or state law for the relief of debtors.  The term "Custodian"
means any receiver, trustee, assignee, liquidator, custodian or similar
official under any Bankruptcy Law.

         A Default under clause (4) is not an Event of Default until the
Trustee or the Holders of at least 25% in principal amount of the Securities
notify the Company of the Default and the Company does not





                                       17
<PAGE>   23
cure such Default within the time specified after receipt of such Notice.  Such
Notice must specify the Default, demand that it be remedied and state that such
notice is a "Notice of Default".

         The Company shall deliver to the Trustee, within 30 days after the
occurrence thereof, written notice in the form of an Officers' Certificate of
any event which with the giving of notice and the lapse of time would become an
Event of Default under clause (4), its status and what action the Company is
taking or proposes to take with respect thereto.

         SECTION 5.02.  Acceleration.  If an Event of Default (other than an
Event of Default specified in Section 5.01(6) or (7)) occurs and is continuing,
the Trustee by notice to the Company, or the Holders of at least 25% in
principal amount of the Securities by notice to the Company and the Trustee,
may declare the principal of (or, in connection with Original Issue Discount
Securities, such portion of the principal amount as may be specified in the
terms of such Securities) and accrued interest on all the Securities to be due
and payable.  Upon such a declaration, such principal (or portion thereof) and
interest shall be due and payable immediately.  If an Event of Default
specified in Section 5.01(6) or (7) occurs and is continuing, the principal of
and interest on all the Securities shall ipso facto become and be immediately
due and payable without any declaration or other act on the part of the Trustee
or any Securityholders.  The Holders of a majority in principal amount of the
Securities by notice to the Trustee may rescind an acceleration and its
consequences if the rescission would not conflict with any judgment or decree
and if all existing Events of Default on the Securities have been cured or
waived (except with respect to nonpayment of principal or interest that has
become due solely because of the acceleration).  No such rescission shall
affect any subsequent Default or impair any right consequent thereto.

         SECTION 5.03.  Other Remedies.  If an Event of Default occurs and is
continuing, the Trustee may pursue any available remedy to collect the payment
of principal of or interest on the Securities or to enforce the performance of
any provision of the Securities or this Indenture.

         The Trustee may maintain a proceeding even if it does not possess any
of the Securities or does not produce any of them in the proceeding.  A delay
or omission by the Trustee or any Securityholder in exercising any right or
remedy accruing upon an Event of Default shall not impair the right or remedy
or constitute a waiver of or acquiescence in the Event of Default.  No remedy
is exclusive of any other remedy.  All available remedies are cumulative.

         SECTION 5.04.  Waiver of Past Defaults.  The Holders of a majority in
principal amount of the Securities by notice to the Trustee may waive an
existing Default and its consequences except (1) a Default in the payment of
the principal of or interest on a Security or (2) a Default in respect of a
provision that under Section 8.02 cannot be amended without the consent of each
Securityholder affected.  When a Default is waived, it is deemed cured, but no
such waiver shall extend to any subsequent or other Default or impair any
consequent right.

         SECTION 5.05.  Control by Majority.  The Holders of a majority in
Principal Amount of the Securities may direct the time, method and place of
conducting any proceeding for any remedy available to the Trustee or of
exercising any trust or power conferred on the Trustee.  However, the Trustee
may refuse to follow any direction that conflicts with law or this Indenture
or, subject to Section 6.01, that the Trustee determines is unduly prejudicial
to the rights of other Securityholders or would involve the Trustee in personal
liability; provided, however, that the Trustee may take any other action deemed
proper by the Trustee that is not inconsistent with such direction.  Prior to
taking any action hereunder, the Trustee shall be entitled to indemnification
satisfactory to it in its sole discretion against all losses and expenses
caused by taking or not taking such action.





                                       18
<PAGE>   24
         SECTION 5.06.  Limitation on Suits.  A Securityholder may not pursue
any remedy with respect to this Indenture or the Securities unless:

                 (1)  the Holder gives to the Trustee written notice stating
         that an Event of Default is continuing;

                 (2)  the Holders of at least 25% in Principal Amount of the
         Securities make a written request to the Trustee to pursue the remedy;

                 (3)  such Holder or Holders offer to the Trustee reasonable
         security or indemnity against any loss, liability or expense;

                 (4)  the Trustee does not comply with the request within 60
         days after receipt of the request and the offer of security or
         indemnity; and

                 (5)  the Holders of a majority of Principal Amount of the
         Securities do not give the Trustee a direction inconsistent with the
         request during such 60-day period.

         A Securityholder may not use this Indenture to prejudice the rights of
another Securityholder or to obtain a preference or priority over another
Securityholder.

         SECTION 5.07.  Rights of Holders To Receive Payment.  Notwithstanding
any other provision of this Indenture, the right of any Holder to receive
payment of principal of and interest on the Securities held by such Holder, on
or after the respective due dates expressed in the Securities, or to bring suit
for the enforcement of any such payment on or after such respective dates,
shall not be impaired or affected without the consent of such Holder.

         SECTION 5.08.  Collection Suit by Trustee.  If an Event of Default in
payment of interest or principal specified in Section 5.01(1) or (2) occurs and
is continuing, the Trustee may recover judgment in its own name and as trustee
of an express trust against the Company for the whole amount of principal and
interest remaining unpaid (together with interest on such unpaid interest as
provided in Section 3.01, to the extent lawful) and the amounts provided for in
Section 6.07.

         SECTION 5.09.  Trustee May File Proofs of Claim.  The Trustee may file
such proofs of claim and other papers or documents as may be necessary or
advisable in order to have the claims of the Trustee and the Securityholders
allowed in any judicial proceedings relative to the Company, its creditors or
its property and, unless prohibited by law or applicable regulations, may vote
on behalf of the Holders in any election of a trustee in bankruptcy or other
person performing similar functions, and any Custodian in any such judicial
proceeding is hereby authorized by each Holder to make payments to the Trustee
and, in the event that the Trustee shall consent to the making of such payments
directly to the Holders, to pay to the Trustee any amount due it for the
reasonable compensation, expenses, disbursements and advances of the Trustee,
its agents and its counsel, and any other amounts due the Trustee under Section
6.07.

         SECTION 5.10.  Priorities.  If the Trustee collects any money pursuant
to this Article 5, it shall pay out the money in the following order:

                 FIRST:  to the Trustee for amounts due under Section 6.07;





                                       19
<PAGE>   25
                 SECOND:  to Securityholders for amounts due and unpaid on the
         Securities for principal and interest, ratably, without preference or
         priority of any kind, according to the amounts due and payable on the
         Securities for principal and interest, respectively; and

                 THIRD:  to the Company.

         The Trustee may fix a record date and payment date for any payment to
Securityholders pursuant to this Section.  At least 15 days before such record
date, the Company shall mail to each Securityholder and the Trustee a notice
that states the record date, the payment date and amount to be paid.

         SECTION 5.11.  Undertaking for Costs.  In any suit for the enforcement
of any right or remedy under this Indenture or in any suit against the Trustee
for any action taken or omitted by it as Trustee, a court in its discretion may
require the filing by any party litigant in the suit of an undertaking to pay
the costs of the suit, and the court in its discretion may assess reasonable
costs, including reasonable attorneys' fees, against any party litigant in the
suit, having due regard to the merits and good faith of the claims or defenses
made by the party litigant.  This Section does not apply to a suit by the
Trustee, a suit by a Holder pursuant to Section 5.07 or a suit by Holders of
more than 10% in Principal Amount of the Securities.

         SECTION 5.12.  Waiver of Stay or Extension Laws.  The Company (to the
extent it may lawfully do so) shall not at any time insist upon, or plead, or
in any manner whatsoever claim or take the benefit or advantage of, any stay or
extension law wherever enacted, now or at any time hereafter in force, which
may affect the covenants or the performance of this Indenture; and the Company
(to the extent that it may lawfully do so) hereby expressly waives all benefit
or advantage of any such law, and shall not hinder, delay or impede the
execution of any power herein granted to the Trustee, but shall suffer and
permit the execution of every such power as though no such law had been
enacted.

                                   ARTICLE 6
                                    TRUSTEE

         SECTION 6.01.  Duties of Trustee.  (a)  If an Event of Default has
occurred and is continuing, the Trustee shall exercise the rights and powers
vested in it by this Indenture 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 such person's own affairs.

         (b)  Except during the continuance of an Event of Default:

                 (1)  the Trustee undertakes to perform such duties and only
         such duties as are specifically set forth in this Indenture and no
         implied covenants or obligations shall be read into this Indenture
         against the Trustee; and

                 (2)  in the absence of bad faith on its part, the Trustee may
         conclusively rely, as to the truth of the statements and the
         correctness of the opinions expressed therein, upon certificates or
         opinions furnished to the Trustee and conforming to the requirements
         of this Indenture.  However, the Trustee shall examine the
         certificates and opinions to determine whether or not they conform to
         the requirements of this Indenture.

         (c)  The Trustee may not be relieved from liability for its own
negligent action, its own negligent failure to act or its own willful
misconduct, except that:





                                       20
<PAGE>   26
                 (1)  this paragraph does not limit the effect of paragraph (b)
         of this Section;

                 (2)  the Trustee shall not be liable for any error of judgment
         made in good faith by a Trust Officer unless it is proved that the
         Trustee was negligent in ascertaining the pertinent facts; and

                 (3)  the Trustee shall not be liable with respect to any
         action it takes or omits to take in good faith in accordance with a
         direction received by it pursuant to Section 5.05.

         (d)  Every provision of this Indenture that in any way relates to the
Trustee is subject to paragraphs (a), (b) and (c) of this Section.

         (e)  The Trustee shall not be liable for interest on any money
received by it except as the Trustee may agree in writing with the Company.

         (f)  Money held in trust by the Trustee need not be segregated from
other funds except to the extent required by law.

         (g)  No provision of this Indenture shall require the Trustee to
expend or risk its own funds or otherwise incur financial liability in the
performance of any of its duties hereunder or in the exercise of any of its
rights or powers, if it shall have reasonable grounds to believe that repayment
of such funds or adequate indemnity against such risk or liability is not
reasonably assured to it.

         (h)  Every provision of this Indenture relating to the conduct or
affecting the liability of or affording protection to the Trustee shall be
subject to the provisions of this Section and to the provisions of the TIA.

         SECTION 6.02.  Rights of Trustee.  (a)  The Trustee may rely on any
document believed by it to be genuine and to have been signed or presented by
the proper person.  The Trustee need not investigate any fact or matter stated
in the document.

         (b)  Before the Trustee acts or refrains from acting, it may require
an Officers' Certificate or an Opinion of Counsel.  The Trustee shall not be
liable for any action it takes or omits to take in good faith in reliance on
the Officers' Certificate or Opinion of Counsel, subject to Section 6.02(e).

         (c)  The Trustee may act through agents and shall not be responsible
for the misconduct or negligence of any agent appointed with due care.

         (d)  The Trustee shall not be liable for any action it takes or omits
to take in good faith which it believes to be authorized or within its rights
or powers.

         (e)  The Trustee may consult with counsel, and the advice or opinion
of counsel with respect to legal matters relating to this Indenture and the
Securities shall be full and complete authorization and protection from
liability in respect to any action taken, omitted or suffered by it hereunder
in good faith and in accordance with the advice or opinion of such counsel.

         SECTION 6.03.  Individual Rights of Trustee.  The Trustee in its
individual or any other capacity may become the owner or pledgee of Securities
and may otherwise deal with the Company or its affiliates with the same rights
it would have if it were not Trustee.  Any Paying Agent, Registrar,
co-registrar or co-paying agent may do the same with like rights.  However, the
Trustee must comply with Sections 6.10 and 6.11.





                                       21
<PAGE>   27
         SECTION 6.04.  Trustee's Disclaimer.  The Trustee shall not be
responsible for and makes no representation as to the validity or adequacy of
this Indenture or the Securities, it shall not be accountable for the Company's
use of the proceeds from the Securities, and it shall not be responsible for
any statement of the Company in the Indenture or in any document issued in
connection with the sale of the Securities or in the Securities other than the
Trustee's certificate of authentication.

         SECTION 6.05.  Notice of Defaults.  If a Default occurs and is
continuing and if it is known to the Trustee, the Trustee shall mail to each
Securityholder notice of the Default within 90 days after it occurs.  Except in
the case of a Default in payment of principal of or interest on any Security
(including payments pursuant to the mandatory redemption provisions of such
Security), the Trustee may withhold the notice if and so long as a committee of
its Trust Officers in good faith determines that withholding the notice is in
the interests of Securityholders.

         SECTION 6.06.  Reports by Trustee to Holders.  Prior to November 1 in
each year, the Trustee shall mail to each Securityholder a brief report dated
as of the preceding September 1 that complies with TIA Section 313(a), if so
required by such Section of the TIA.  The Trustee also shall comply with TIA
Section 313(b).

         A copy of each report at the time of its mailing to Securityholders
shall be filed with the SEC and each stock exchange on which the Securities are
listed.  The Company agrees to notify promptly the Trustee whenever the
Securities become listed on any stock exchange and of any delisting thereof.

         SECTION 6.07.  Compensation and Indemnity.  The Company shall pay to
the Trustee from time to time reasonable compensation for its services,
including those arising in the Trustee's performance of its duties under
Sections 5.02, 5.03, 5.08 hereof, and to the extent permitted by law, Section
5.09 hereof.  The Trustee's compensation shall not be limited by any law on
compensation of a trustee of an express trust.  The Company shall reimburse the
Trustee upon request for all reasonable out-of-pocket expenses incurred or made
by it, including costs of collection, in addition to the compensation for its
services.  Such expenses shall include the reasonable compensation and
expenses, disbursements and advances of the Trustee's agents, counsel,
accountants and experts.  The Company shall indemnify the Trustee against any
and all loss, liability or expense (including attorneys' fees) incurred by it
in connection with the administration of this trust and the performance of its
duties hereunder.  The Trustee shall notify the Company promptly of any claim
for which it believes it may seek indemnity.  Failure by the Trustee to so
notify the Company shall not relieve the Company of its obligations hereunder.
The Company shall defend the claim and the Trustee may have separate counsel
and the Company shall pay the reasonable fees and expenses of such counsel.
The Company need not reimburse any expense or indemnify against any loss,
liability or expense to the extent incurred by the Trustee through the
Trustee's own willful misconduct, negligence or bad faith.

         To secure the Company's payment obligations in this Section, the
Trustee shall have a Lien prior to the Securities on all money or property held
or collected by the Trustee, except that held in trust to pay principal of and
interest on particular Securities.

         The Company's payment obligations pursuant to this Section shall
survive the discharge of this Indenture.

         For purposes of this Section, the term "Trustee" shall include any
predecessor Trustee, provided that any Trustee hereunder shall not be liable
for the willful misconduct, negligence or bad faith of any other Trustee
hereunder.





                                       22
<PAGE>   28
         SECTION 6.08.  Replacement of Trustee.  The Trustee may resign at any
time by so notifying the Company.  The Holders of a majority in Principal
Amount of the Securities may remove the Trustee by so notifying the Trustee and
may appoint a successor Trustee.  The Company shall remove the Trustee if:

                 (1)  the Trustee fails to comply with Section 6.10;

                 (2)  the Trustee is adjudged bankrupt or insolvent;

                 (3)  a receiver or other public officer takes charge of the
         Trustee or its property; or

                 (4)  the Trustee otherwise becomes incapable of acting.

         If the Trustee resigns or is removed or if a vacancy exists in the
office of Trustee for any reason (the Trustee in such event being referred to
herein as the retiring Trustee), the Company shall promptly appoint a successor
Trustee.

         A successor Trustee shall deliver a written acceptance of its
appointment to the retiring Trustee and to the Company.  Thereupon the
resignation or removal of the retiring Trustee shall become effective, and the
successor Trustee shall have all the rights, powers and duties of the Trustee
under this Indenture.  The successor Trustee shall mail a notice of its
succession to Securityholders.  The retiring Trustee shall promptly transfer
all property held by it as Trustee to the successor Trustee, subject to the
Lien provided for in Section 6.07.

         If a successor Trustee does not take office within 60 days after the
retiring Trustee resigns or is removed, the retiring Trustee, the Company or
the Holders of a majority in Principal Amount of the Securities may petition
any court of competent jurisdiction for the appointment of a successor Trustee.

         If the Trustee fails to comply with Section 6.10, any Securityholder
(subject to compliance with TIA Section 310(b)(iii)) may petition any court of
competent jurisdiction for the removal of the Trustee and the appointment of a
successor Trustee.

         Notwithstanding the replacement of the Trustee pursuant to this
Section, the Company's obligations under Section 6.07 shall continue for the
benefit of the retiring Trustee.

         SECTION 6.09.  Successor Trustee by Merger.  If the Trustee
consolidates with, merges or converts into, or transfers all or substantially
all its corporate trust business or assets to, another corporation or banking
association, the resulting, surviving or transferee corporation without any
further act shall be the successor Trustee.

         In case at the time such successor or successors by merger, conversion
or consolidation to the Trustee shall succeed to the trusts created by this
Indenture any of the Securities shall have been authenticated but not
delivered, any such successor to the Trustee may adopt the certificate of
authentication of any predecessor trustee, and deliver such Securities so
authenticated; and in case at that time any of the Securities shall not have
been authenticated, any successor to the Trustee may authenticate such
Securities either in the name of any predecessor hereunder or in the name of
the successor to the Trustee; and in all such cases such certificates shall
have the full force which it is anywhere in the Securities or in this Indenture
provided that the certificate of the Trustee shall have.

         SECTION 6.10.  Eligibility; Disqualification.  The Trustee shall at
all times satisfy the requirements of TIA Section 310(a).  The Trustee shall
have a combined capital and surplus of at least





                                       23
<PAGE>   29
$50,000,000 as set forth in its most recent published annual report.  The
Trustee shall comply with TIA Section 310(b).

         SECTION 6.11.  Preferential Collection of Claims Against Company.  The
Trustee shall comply with TIA Section 311(a), excluding any creditor
relationship listed in TIA Section 311(b).  A Trustee who has resigned or been
removed shall be subject to TIA Section 311(a) to the extent indicated.

                                   ARTICLE 7
                       DISCHARGE OF INDENTURE; DEFEASANCE

         SECTION 7.01.  Discharge of Liability on Securities; Defeasance.  (a)
When (i) the Company delivers to the Trustee all outstanding Securities (other
than Securities replaced pursuant to Section 2.09) for cancellation or (ii) all
outstanding Securities have become due and payable and the Company irrevocably
deposits with the Trustee funds sufficient to pay at maturity all outstanding
Securities, including interest thereon (other than Securities replaced pursuant
to Section 2.09), and if in either case the Company pays all other sums payable
hereunder by the Company, then this Indenture shall, subject to Section
7.01(c), cease to be of further effect.  The Trustee shall acknowledge
satisfaction and discharge of this Indenture on demand of the Company
accompanied by an Officers' Certificate and an Opinion of Counsel.

         (b)  Subject to Sections 7.01(c) and 7.02, the Company at any time may
terminate (i) all its obligations under this Indenture with respect to the
Securities of a series ("Legal Defeasance Option") or (ii) its obligations
under Sections 3.03 and 3.04 and the operation of Sections 5.01(4) and 5.01(5)
("Covenant Defeasance Option") with respect to a series of Securities.  The
Company may exercise its Legal Defeasance Option notwithstanding its prior
exercise of its Covenant Defeasance Option.

         If the Company exercises its Legal Defeasance Option, payment of the
Securities of such series may not be accelerated because of an Event of
Default.  If the Company exercises its Covenant Defeasance Option, payment of
the Securities of such series may not be accelerated because of an Event of
Default specified in Section 5.01(4) or 5.01(5).

         Upon satisfaction of the conditions set forth herein and upon request
of the Company, the Trustee shall acknowledge in writing the discharge of those
obligations that the Company terminates.

         (c)  Notwithstanding clauses (a) and (b) above, the Company's
obligations with respect to such series in Sections 2.05, 2.06, 2.07, 2.08,
2.09, 6.07, 6.08, 7.03 and 7.04 shall survive until the Securities of such
series have been paid in full.  Thereafter, the Company's obligations in
Sections 6.07 and 7.04 with respect to such series shall survive.

         SECTION 7.02.  Conditions to Defeasance.  The Company may exercise its
Legal Defeasance Option or its Covenant Defeasance Option only if:

                 (1)  the Company irrevocably deposits in trust with the
         Trustee money or U.S. Government Obligations for the payment of
         principal and interest on the Securities of the series to be defeased
         to maturity or redemption, as the case may be;

                 (2)  the Company delivers to the Trustee a certificate from a
         nationally recognized firm of independent accountants expressing its
         opinion that the payments of principal and interest when due and
         without reinvestment on the deposited U.S.  Government Obligations
         plus any deposited money without investment will provide cash at such
         times and in such amounts (but, in the case





                                       24
<PAGE>   30
         of the Legal Defeasance Option only, not more than such amounts) as
         will be sufficient to pay principal and interest when due on all the
         Securities of such series to maturity or redemption, as the case may
         be;

                 (3)  in the case of the Legal Defeasance Option, 91 days pass
         after the deposit is made and during the 91-day period no Default
         specified in Section 5.01(6) or (7) occurs which is continuing at the
         end of the period;

                 (4)  no Default has occurred and is continuing on the date of
         such deposit and after giving effect thereto; and

                 (5)  the Company delivers to the Trustee an Officers'
         Certificate and an Opinion of Counsel, each stating that all
         conditions precedent to the defeasance and discharge of the Securities
         of such series as contemplated by this Article 7 have been complied
         with.

         Before or after a deposit, the Company may make arrangements
satisfactory to the Trustee for the redemption of Securities at a future date
in accordance with Article 9.

         SECTION 7.03.  Application of Trust Money.  The Trustee shall hold in
trust money or U.S. Government Obligations deposited with it pursuant to this
Article 7.  It shall apply the deposited money and the money from U.S.
Government Obligations through the Paying Agent and in accordance with this
Indenture to the payment of principal of and interest on the relevant
Securities.

         SECTION 7.04.  Repayment to Company.  The Trustee and the Paying Agent
shall promptly turn over to the Company upon request any excess money or
securities held by them at any time not required for the payment of the
Securities.

         With respect to the money or securities held under Sections 7.01 and
7.02, in determining whether such money or securities are excess, the Trustee
may rely on the certificate provided to it under Section 7.02(2).

         Subject to any applicable abandoned property law, the Trustee and the
Paying Agent shall pay to the Company upon request any money held by them for
the payment of principal or interest that remains unclaimed for two years, and,
thereafter, Securityholders entitled to the money must look to the Company for
payment as general creditors.

                                   ARTICLE 8
                                   AMENDMENTS

         SECTION 8.01.  Without Consent of Holders.  The Company and the
Trustee may amend this Indenture or the Securities without notice to or consent
of any Securityholder:

                 (1)  to cure any ambiguity, omission, defect or inconsistency;

                 (2)  to comply with Article 4;

                 (3)  to provide for uncertificated Securities in addition to
         or in place of certificated Securities; provided, however, that the
         uncertificated Securities are issued in registered form for purposes
         of Section 163(f) of the Internal Revenue Code of 1986, as amended, or
         in a manner such that the uncertificated Securities are described in
         Section 163(f)(2)(B) of the Internal Revenue Code of 1986, as amended;





                                       25
<PAGE>   31
                 (4)  to add guarantees with respect to the Securities;

                 (5)  to add to the covenants of the Company for the benefit of
         the Holders or to surrender any right or power herein conferred upon
         the Company;

                 (6)  to comply with any requirements of the SEC in connection
         with qualifying this Indenture under the TIA; or

                 (7)  to make any change that does not adversely affect the
         rights of any Securityholder in any material respect.

         After an amendment under this Section becomes effective, the Company
shall mail to Securityholders a notice briefly describing such amendment.  The
failure to give such notice to all Securityholders, or any defect therein,
shall not impair or affect the validity of an amendment under this Section.

         SECTION 8.02.  With Consent of Holders.  The Company and the Trustee
may amend this Indenture or the Securities without notice to any Securityholder
but with the written consent of the Holders of at least a majority in principal
amount of the Securities.  However, without the consent of each Securityholder
affected, an amendment may not:

                 (1)  reduce the amount of Securities whose Holders must
         consent to an amendment;

                 (2)  reduce the rate of or extend the time for payment of
         interest on any Security;

                 (3)  reduce the principal of or extend the fixed maturity of
         any Security;

                 (4)  reduce the premium payable upon the redemption of any
         Security or change the time at which any Security may or shall be
         redeemed;

                 (5)  make any Security payable in money other than that stated
         in the Security; or

                 (6)  make any change in Section 5.04 or this Section;

and, provided further, that in case more than one series of Securities (or
Securities of a single series which have different Terms) shall be outstanding
under this Indenture, and any such proposed amendment shall affect the rights
of Holders of the Securities of one or more series (or Securities of a single
series which have different Terms) and shall not affect the rights of Holders
of the Securities of one or more of the other series (or Securities of a single
series which have different Terms), then only Holders of Securities to be
affected shall have authority or be required to consent to or approve such
amendment.  Any waiver of a default provided for in Section 5.04 shall be
deemed to affect the Securities of all series, and, subject to the foregoing,
any modification of the provisions of any sinking fund or covenant established
in respect of Securities of a particular series (or Securities of a single
series having the same Terms) shall be deemed to affect only such Securities.

         It shall not be necessary for the consent of the Holders under this
Section 8.02 to approve the particular form of any proposed amendment, but it
shall be sufficient if such consent approves the substance thereof.

         After an amendment under this Section becomes effective, the Company
shall mail to Holders of the affected Securities a notice briefly describing
such amendment.  The failure to give such notice to all





                                       26
<PAGE>   32
Securityholders (or all Holders of the affected Securities), or any defect
therein, shall not impair or affect the validity of an amendment under this
Section.

         SECTION 8.03.  Compliance with Trust Indenture Act.  Every amendment
to this Indenture or the Securities shall comply with the TIA as then in
effect.

         SECTION 8.04.  Revocation and Effect of Consents and Waivers.  A
consent to an amendment or any other action hereunder or a waiver by a Holder
of a Security shall bind the Holder and every subsequent Holder of that
Security or portion of the Security that evidences the same debt as the
consenting Holder's Security, even if notation of the consent or waiver is not
made on the Security.  However, any such Holder or subsequent Holder may revoke
the consent or waiver as to such Holder's Security or portion of the Security
if the Trustee receives the notice of revocation before the date the amendment
or waiver becomes effective.  After an amendment or waiver becomes effective,
it shall bind every Securityholder.

         The Company may, but shall not be obligated to, fix a record date for
the purpose of determining the Securityholders entitled to take any action
under this Indenture by vote or consent.  Such record date shall be the later
of 30 days prior to the first solicitation of such consent or vote or the date
of the most recent list of Holders of the affected Securities furnished to the
Trustee pursuant to Section 2.07 prior to such solicitation.  If a record date
is fixed, those persons who were Securityholders at such record date (or their
duly designated proxies), and only those persons, shall be entitled to take
such action by vote or consent or to revoke any vote or consent previously
given, whether or not such persons continue to be Securityholders after such
record date.

         SECTION 8.05.  Notation on or Exchange of Securities.  If an amendment
changes the terms of a Security, the Trustee may require the Holder of the
Security to deliver it to the Trustee.  The Trustee may place an appropriate
notation on the Security regarding the changed terms and return it to the
Holder.  Alternatively, if the Company or the Trustee so determines, the
Company in exchange for the Security shall issue and the Trustee shall
authenticate a new Security that reflects the changed terms.  Failure to make
the appropriate notation or to issue a new Security shall not affect the
validity of such amendment.

         SECTION 8.06.  Trustee To Sign Amendments.  The Trustee shall sign any
amendment authorized pursuant to this Article 8 if the amendment does not
adversely affect the rights, duties, liabilities or immunities of the Trustee.
If it does, the Trustee may but need not sign it.  In signing such amendment
the Trustee shall be entitled to receive indemnity reasonably satisfactory to
it and to receive, and (subject to Section 6.01) shall be fully protected in
relying upon, an Officers' Certificate and an Opinion of Counsel stating that
such amendment is authorized or permitted by this Indenture.

                                   ARTICLE 9
                                   REDEMPTION

         SECTION 9.01.  Applicability.  Securities of any series which are
redeemable before their final maturity shall be redeemable in accordance with
their Terms and (except as otherwise specified as contemplated by Section 2.01
for Securities of any series) in accordance with this Article.

         SECTION 9.02.  Notice to Trustee.  The Company may, with respect to
any series of Securities (or Securities of a series having the same Terms),
reserve the right to redeem and pay such Securities or any part thereof, or may
covenant to redeem and pay the series of Securities (or Securities of a series
having the same Terms) or any part thereof, before maturity at such time and on
such terms as provided for in such Securities. If a series of Securities (or
Securities of a series having the same Terms) is redeemable and the Company
wants or is obligated to redeem all or part of the series of Securities (or





                                       27
<PAGE>   33
Securities of a series having the same Terms) pursuant to the Terms of such
Securities, the Company shall notify the Trustee of the redemption date and the
Principal Amount of the series of Securities (or Securities of a series having
the same Terms) to be redeemed.  The Company shall give such notice at least 60
days before the redemption date (or such shorter notice as may be acceptable to
the Trustee in its sole discretion).

         SECTION 9.03.  Selection of Securities To Be Redeemed.  If less than
all the Securities of a series (or Securities of a series having the same
Terms) are to be redeemed, the Trustee, not more than 60 days prior to the
redemption date, shall select the Securities of the series (or Securities of a
series having the same Terms) to be redeemed pro rata or by lot or by such
other method as the Trustee shall deem fair and appropriate.  The Trustee shall
make the selection from Securities that are outstanding and that have not
previously been called for redemption.  Securities of the series (or Securities
of a series having the same Terms) and portions of them selected by the Trustee
shall be in amounts of $1,000 or integral multiples of $1,000 or with respect
to Securities of any Series issuable in other denominations pursuant to Section
2.01(8), in amounts equal to the minimum principal denomination for each such
series and in integral multiples thereof.  Provisions of this Indenture that
apply to Securities of that series (or Securities of a series having the same
Terms) called for redemption also apply to portions of Securities of that
series (or Securities of a series having the same Terms) called for redemption.
The Trustee shall promptly notify the Company in writing of the Securities
selected for redemption and, in the case of any Securities selected for partial
redemption, the Principal Amount thereof to be redeemed.

         SECTION 9.04.  Notice of Redemption. (a)  At least 30 days but not
more than 60 days before a redemption date, unless a shorter period is
specified in the Terms of the Securities to be redeemed, the Company shall
cause to be mailed a notice of redemption by first-class mail to each Holder of
Securities that are to be redeemed.

         (b)     All notices of redemption shall identify the Securities to be
redeemed and shall state:

                 (1)  the redemption date;

                 (2)  the redemption price and interest, if any, payable upon
         such redemption;

                 (3)  if less than all the outstanding Securities of a series
         (or Securities of a series having the same Terms) are to be redeemed,
         the identification (and, in the case of partial redemption, the
         Principal Amounts) of the particular Securities to be redeemed;

                 (4)  the name and address of the Paying Agent;

                 (5)  that the Securities called for redemption must be
         surrendered to the Paying Agent to collect the redemption price; and

                 (6)  that interest on Securities called for redemption ceases
         to accrue on and after the redemption date.

         (c)     If at the time of mailing of any notice of redemption the
         Company shall not have deposited or caused to be deposited with the
         Trustee moneys sufficient to redeem all the Securities called for
         redemption, such notice shall state that it is subject to the deposit
         of the redemption moneys with the Trustee not later than the opening
         of business on the redemption date and shall be of no effect unless
         such moneys are so deposited.  If such moneys are not deposited by
         such date and time, the Trustee shall promptly notify the holders of
         all Securities called for redemption of such fact.





                                       28
<PAGE>   34
         At the Company's request, the Trustee shall give the notice of
redemption in the Company's name and at the Company's expense.

         SECTION 9.05.  Effect of Notice of Redemption.  Once notice of
redemption is mailed, Securities called for redemption become due and payable
on the redemption date at the redemption price.  Any failure to mail notice of
redemption or any defect therein shall not affect the redemption of any other
Securities called for redemption.  Upon surrender to the Paying Agent of such
Securities, such Securities shall be paid at the redemption price plus accrued
interest to the redemption date, but installments of interest due on or prior
to the redemption date will be payable to the Holders of such Securities of
record at the close of business on the relevant record dates, unless otherwise
specified in the Terms of such Securities.

         SECTION 9.06.  Deposit of Redemption Price.  On or before the
redemption date, the Company shall deposit with the Paying Agent money
sufficient to pay the redemption price of and interest accrued to the
redemption date on all Securities to be redeemed on that date.

         SECTION 9.07.  Securities Redeemed in Part.  Upon surrender of a
Security that is redeemed in part, the Company shall issue and the Trustee
shall authenticate for the Holder of that Security a new Security or Securities
of the same series and terms in authorized denominations equal in aggregate
principal amount to the unredeemed portion of the Security surrendered.

                                   ARTICLE 10
                                 SINKING FUNDS

         SECTION 10.01.  Applicability.  The provisions of this Article shall
be applicable to any sinking fund for the retirement of Securities, except as
otherwise specified as contemplated by Section 2.01 for Securities of any
series.

         The minimum amount of any sinking fund payment provided for by the
Terms of any Securities is herein referred to as a "Mandatory Sinking Fund
Payment", and any payment in excess of such minimum amount provided for by the
terms of such Securities is herein referred to as an "Optional Sinking Fund
Payment".  If provided for by the Terms of Securities, the cash amount of any
sinking fund payment may be subject to reduction as provided in Section 10.02.
Each sinking fund payment shall be applied to the redemption of Securities of
any series (or Securities of a series having the same Terms) as provided for by
the Terms of such Securities.

         SECTION 10.02.  Satisfaction of Sinking Fund Payments with Securities.
The Company may, in satisfaction of all or any part of any sinking fund payment
with respect to the Securities to be made pursuant to the Terms of such
Securities as provided for by such Terms, (1) deliver outstanding Securities of
such series having the same Terms (other than any of such Securities previously
called for redemption) and (2) apply as credit Securities of such series having
the same Terms which have been redeemed either at the election of the Company
pursuant to the Terms of such Securities or through the application of
permitted Optional Sinking Fund Payments pursuant to the Terms of such
Securities, provided that such Securities have not been previously so credited.
Such Securities shall be received and credited for such purpose by the Trustee
at the price specified in such Securities for redemption through operation of
the sinking fund and the amount of such sinking fund payment shall be reduced
accordingly.  If as a result of the delivery or credit of Securities in lieu of
cash payments pursuant to this Section 10.02, the Principal Amount of
Securities to be redeemed in order to exhaust the aforesaid cash payment shall
be less than $100,000, the Trustee need not call Securities for redemption,
except upon receipt of a Company Order that such action be taken, and such cash
payment shall be held by the Trustee or a Paying Agent and applied to the next
succeeding sinking fund payment with respect to such series of Securities (or





                                       29
<PAGE>   35
Securities of such series having the same Terms), provided, however, that the
Trustee or such Paying Agent shall at the request of the Company from time to
time pay over and deliver to the Company any cash payment so being held by the
Trustee or such Paying Agent upon delivery by the Company to the Trustee of
Securities of that series having the same Terms purchased by the Company having
an unpaid Principal Amount equal to the cash payment required to be released to
the Company.

         SECTION 10.03.  Redemption of Securities for Sinking Fund.  Not less
than 60 days prior to each sinking fund payment date for any series of
Securities (or Securities of such series having the same Terms), the Company
will deliver to the Trustee an Officers' Certificate specifying the amount of
the next ensuing Mandatory Sinking Fund Payment for that series (or Securities
of such series having the same Terms) pursuant to the Terms of that series, the
portion thereof, if any, which is to be satisfied by payment of cash and the
portion thereof, if any, which is to be satisfied by delivering and crediting
of Securities of that series (or Securities of such series having the same
Terms) pursuant to Section 10.02, and the optional amount, if any, to be added
in cash to the next ensuing Mandatory Sinking Fund Payment, and the Company
shall thereupon be obligated to pay the amount therein specified.  Not less
than 30 days before each such sinking fund payment date the Trustee shall
select the Securities to be redeemed upon such sinking fund payment date in the
manner specified in Section 9.03 and cause notice of the redemption thereof to
be given in the name of and at the expense of the Company in the manner
provided in Section 9.04.  Such notice having been duly given, the redemption
of such Securities shall be made upon the terms and in the manner stated in
Sections 9.05, 9.06 and 9.07.

                                   ARTICLE 11
                                 MISCELLANEOUS

         SECTION 11.01.  Trust Indenture Act Controls.  If any provision of
this Indenture limits, qualifies or conflicts with the duties imposed by
operation of TIA Section 318(c), the imposed duties shall control.

         SECTION 11.02.  Notices.  Any notice or communication shall be in
writing and delivered in person or mailed by first-class mail addressed as
follows:

         if to the Company:       The Columbia Gas System, Inc.
                                  20 Montchanin Road
                                  Wilmington, DE 19807
                                  Attention: Corporate Secretary

         if to the Trustee:       Marine Midland Bank
                                  140 Broadway
                                  New York, NY 10005
                                  Attention: Corporate Trust Administration

         The Company or the Trustee by notice to the other may designate
additional or different addresses for subsequent notices or communications.

         Any notice or communication mailed to a Securityholder shall be mailed
to the Securityholder at the Securityholder's address as it appears on the
registration books of the Registrar and shall be sufficiently given if so
mailed within the time prescribed.

         Failure to mail a notice or communication to a Securityholder or any
defect in it shall not affect its sufficiency with respect to other
Securityholders.  If a notice or communication is mailed in the manner provided
above, it is duly given, whether or not the addressee receives it.





                                       30
<PAGE>   36
         SECTION 11.03.  Communication by Holders with Other Holders.
Securityholders may communicate pursuant to TIA Section 312(b) with other
Securityholders with respect to their rights under this Indenture or the
Securities.  The Company, the Trustee, the Registrar and anyone else shall have
the protection of TIA Section 312(c).

         SECTION 11.04.  Certificate and Opinion as to Conditions Precedent.
Upon any request or application by the Company to the Trustee to take or
refrain from taking any action under this Indenture, the Company shall furnish
to the Trustee:

                 (1)  an Officers' Certificate in form and substance reasonably
         satisfactory to the Trustee stating that, in the opinion of the
         signers, all conditions precedent, if any, provided for in this
         Indenture relating to the proposed action have been complied with; and

                 (2)  an Opinion of Counsel in form and substance reasonably
         satisfactory to the Trustee stating that, in the opinion of such
         counsel, all such conditions precedent have been complied with.

         SECTION 11.05.  Statements Required in Certificate or Opinion.  Each
certificate or opinion with respect to compliance with a covenant or condition
provided for in this Indenture shall include:

                 (1)  a statement that the person making such certificate or
         opinion has read such covenant or condition;

                 (2)  a brief statement as to the nature and scope of the
         examination or investigation upon which the statements or opinions
         contained in such certificate or opinion are based;

                 (3)  a statement that, in the opinion of such person, he has
         made such examination or investigation as is necessary to enable him
         to express an informed opinion as to whether or not such covenant or
         condition has been complied with; and

                 (4)  a statement as to whether or not, in the opinion of such
         person, such covenant or condition has been complied with.

         SECTION 11.06.  When Securities Disregarded.  In determining whether
the Holders of the required principal amount of Securities have concurred in
any direction, waiver or consent, Securities owned by the Company or by any
person directly or indirectly controlling or controlled by or under direct or
indirect common control with the Company shall be disregarded and deemed not to
be outstanding, except that, for the purpose of determining whether the Trustee
shall be protected in relying on any such direction, waiver or consent, only
Securities which the Trustee knows are so owned shall be so disregarded.  Also,
subject to the foregoing, only Securities outstanding at the time shall be
considered in any such determination.

         SECTION 11.07.  Rules by Trustee, Paying Agent and Registrar.  The
Trustee may make reasonable rules for action by or a meeting of Securityholders
or for evidencing the due execution of consents or waivers by Securityholders.
The Registrar and the Paying Agent may make reasonable rules for their
functions.

         SECTION 11.08.  Legal Holidays.  A "Legal Holiday" is a Saturday, a
Sunday or a day on which banking institutions are not required to be open in
the State of New York.  If a payment date is a Legal Holiday, payment shall be
made on the next succeeding day that is not a Legal Holiday, and no interest





                                       31
<PAGE>   37
shall accrue for the intervening period.  If a regular record date is a Legal
Holiday, the record date shall not be affected.

         SECTION 11.09.  Governing Law.  This Indenture and the Securities
shall be governed by, and construed in accordance with, the laws of the State
of New York but without giving effect to applicable principles of conflicts of
law to the extent that the application of the laws of another jurisdiction
would be required thereby.

         SECTION 11.10.  No Recourse Against Others.  A director, officer,
employee or stockholder, as such, of the Company shall not have any liability
for any obligations of the Company under the Securities of this Indenture or
for any claim based on, in respect of or by reason of such obligations or their
creation.  By accepting a Security, each Securityholder shall waive and release
all such liability.  The waiver and release shall be part of the consideration
for the issue of the Securities.

         SECTION 11.11.  Successors.  All agreements of the Company in this
Indenture and the Securities shall bind its successors.  All agreements of the
Trustee in this Indenture shall bind its successors.

         SECTION 11.12.  Multiple Originals.  The parties may sign any number
of copies of this Indenture.  Each signed copy shall be an original, but all of
them together represent the same agreement.  One signed copy is enough to prove
this Indenture.

         SECTION 11.13.  Table of Contents; Headings.  The table of contents
and headings of the Articles and Sections of this Indenture have been inserted
for convenience of reference only, are not intended to be considered a part
hereof and shall not modify or restrict any of the terms or provisions hereof.





                                       32
<PAGE>   38
         IN WITNESS WHEREOF, the parties have caused this Indenture to be duly
executed as of the date first written above.

<TABLE>
<S>                                                         <C>                                                              
                                                            THE COLUMBIA GAS SYSTEM, INC.                                    
                                                                                                                             
                                                                                                                             
Attest:   //s// C. M. Afshar                                by:   //s// L. J. Bainter                                        
       --------------------------------------                  ----------------------------------------------                
                  Secretary                                         L. J. Bainter, Treasurer                                 
                                                                                                                             
                                                                                                                             
                                                                                                                             
                                                                                                                             
[CORPORATE SEAL]                                                                                                             
                                                                                                                             
                                                                                                                             
                                                                                                                             
                                                                                                                             
                                                                                                                             
                                                            MARINE MIDLAND BANK, as Trustee                                  
                                                                                                                             
                                                                                                                             
Attest:   //s// Robert A. Conrad                            by:   //s// Metin Caner                                          
       --------------------------------------                  ----------------------------------------------                
             Assistant Vice President                               Metin Caner, Vice President                              





[CORPORATE SEAL]
</TABLE>





                                       33
<PAGE>   39
STATE OF DELAWARE)
                 ) ss:
New Castle County)


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.




                                             //s// Ellen M. Patterson       
                                          -------------------------------------
                                          Notary Public
                                          
                                          
                                             10/24/98                          
                                          -------------------------------------
                                          My commission expires






                                       34
<PAGE>   40
STATE OF NEW YORK )
                  ) ss:
County of New York)



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.




                                              //s// S. C. Derenchuk            
                                          -------------------------------------
                                          Notary Public
                                          
                                          
                                              6/12/97                          
                                          -------------------------------------
                                          My commission expires






                                       35
<PAGE>   41


FROM:            Kate Baird
TO:              sunshine
DATE:            2/2/96 8:14am
SUBJECT:         January 31, 1996 Sunshine Report

REPORT ON THE FERC SUNSHINE MEETING
Wednesday, January 31, 1996

ITEMS:
1.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NOS.  RP95-408-004 & 005)

2.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NO. RP96-94-000)

3.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NO. RP96-112-000)

4.               COVE POINT LNG LIMITED PARTNERSHIP
                 (DOCKET NO. MG95-7-001)

5.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NO. CP95-482-001)

6.               TEXAS EASTERN TRANSMISSION CORPORATION
                 (DOCKET NO. RP85-170-014)

7.               PANHANDLE EASTERN PIPE LINE COMPANY
                 (DOCKET NO. RP95-397-000)

B.               GAS RESEARCH INSTITUTE
                 (DOCKET NO. RP95-374-002)

9.               TEXAS EASTERN TRANSMISSION CORPORATION
                 (DOCKET NO. CP95-681-001)

10.              TRANSCONTINENTAL GAS PIPE LINE CORPORATION
                 (DOCKET NO. CP94-109-002)

11.              TEXAS EASTERN TRANSMISSION CORPORATION
                 (DOCKET NO. CP95-218-000)

12.              NOTICE OF INQUIRY
                 (DOCKET NO. RM96-6)

13.              REQUEST FOR COMMENTS
                 (DOCKET NOS.  RM95-6 AND RM96-7)



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





1.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NOS.  RP95-408-004 & 005)

                 The Commission approved a draft order accepting the Appendix A
tariff sheets to TCO's December 29,
<PAGE>   42
1995 motion rates filing as adjusted, to become effective February 1, 1996,
subject to refund.  The Commission also accepted and suspended, to be effective
May 1, 1996, the Appendix B tariff sheets, subject to refund and the condition
TCO refile, within 15 days of the date of the order, tariff sheets reflecting
the elimination of the income tax allowance in calculating the carrying costs
for the stranded facility charge. On this point, the Commission noted that
close scrutiny of TCO's proposed amounts indicate that an income tax allowance
of approximately $2.1 million is embedded in the stranded costs. The August 31
suspension order had directed TCO to eliminate the return and income tax
allowances associated with the unamortized stranded costs balance and use in
its place an interest carrying charge.

                 As to the protests raised by Cities, Equitable and
Mountaineer, he Commission stated that they can be left to the hearing process
in this proceeding.  In addition, the Commission noted, with respect to Cities'
concern regarding the need of a bond and escrow, that such action is not
necessary and the Commission will not order it.  TCO has emerged from
bankruptcy and, therefore, the refund condition should be adequate protection
for TCO's customers.

                 In accordance with the agreed upon settlement period
procedures, TCO will move only 75 percent of its originally proposed increase
into effect on February 1. If an overall settlement in principle has not been
achieved by May 1, or if settlement discussions are terminated at any time
after the end of the Settlement Period, TCO can move into effect the entire
filed-for rates, reflected in the Appendix B tariff sheets, on May 1 or any
subsequent date.


2.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NO. RP96-94-000)

                 The Commission approved a letter order accepting TCO's filing
to adjust its Account No. 191 balance in order to reflect a net credit of
$847,459.  The letter order also grants TCO's request for a waiver of its
tariff to permit it to adjust its Account No. 191 balance for future
transportation and exchange adjustments with Tennessee, until December 31,
1996.  Also, TCO can seek an additional extension at the end of the waiver
period if necessary.  The waiver is subject to the same conditions the
Commission imposed in its March 31, 1995 letter order in Docket No.
RP94-273-001, i.e. the extension is granted as long as it results in a
reduction in TCO's Account No. 191 direct bill.


3.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NO. RP96-112-000)

                 The Commission approved a letter order granting waiver of the
30 day notice requirement and accepted TCO's January 5 filing to include the
Stranded Facilities Charge (SFC) in the apportionment of discounts in the
discounting section of its tariff, effective February 1, 1996.  The SFC will be
discounted last, on a pro rata basis with Stranded TCRA charges and
non-transition cost surcharges, in accordance with the Commission's policy on
the attribution of discounts.


4.               COVE POINT LNG LIMITED PARTNERSHIP
                 (DOCKET NO. MG95-7-001)

                 The Commission approved an order finding that the standards of
conduct submitted by Cove Point are acceptable.


5.               COLUMBIA GAS TRANSMISSION CORPORATION
                 (DOCKET NO. CP95-482-001)

                 The Commission approved a tolling order to afford additional
time for consideration of the issues raised in UGI's request for rehearing of
the Commission's order issued on December 5, 1995.  The December 5 order
granted TCO authority to construct and operate an additional delivery point in
order to provide service to Pennsylvania Power and Light's Martins Creek
facility through an interconnect with Interstate Energy Company.


6.               TEXAS EASTERN TRANSMISSION CORPORATION
                 (DOCKET NO. RP85-170-014)
<PAGE>   43
                 The Commission accepted the agreement and refund proposal
filed by Texas Eastern in this proceeding on November 21, 1995.  Under the
agreement, Texas Eastern will refund Order No. 94 production related costs that
it had previously collected from TCO pursuant to an unlawful direct bill.  The
refund will consist of (1) a principal amount of $11,948,555.73, (2) $1,440,000
in interest for the period prior to October 1, 1994, and (3) additional
interest on the principal amount for the period October 1, 1994, to the date of
the refund.  The refund is to be made within 10 days of the date of an order
by the US Court of Appeals for the DC Circuit, granting a joint motion by the
parties to withdraw their appeals, becomes final.


7.               PANHANDLE EASTERN PIPE LINE COMPANY
                 (DOCKET NO. RP95-397-000)

                 The Commission approved a lengthy order accepting Panhandle's
proposal to implement a Limited Firm Transportation Service on its system under
Rate Schedule LFT under which transportation service would be available that
cannot be interrupted more than 10 days in any given month.  The Commission
said it finds the proposal is a reasonable one and allows flexibility for
customers that want a less costly form of firm transportation without the
insecurity of interruptible transportation.  The order also addresses the
concerns of the protesters which were reviewed at a technical conference held
on November 9, 1995.  Among other things, the protesters expressed concern that
LFT unfairly competes with released capacity.  The Commission noted that the
protesters are really being critical of the capacity release program when they
complain about the advantages of LFT.  These may or may not be valid arguments,
but the LFT proceeding is not the appropriate place to change the capacity
release program.


8.               GAS RESEARCH INSTITUTE
                 (DOCKET NO. RP95-374-002)

                 The Commission denied The Fertilizer Institute's (TFI's)
request for rehearing of Opinion 402 approving GRI's second year of its
1995-1996 RD&D program, the related five-year research and development plan for
1996-2000, and funding for GRI's 1996 RD&D activities.  TFI had requested
rehearing alleging that the Commission had erred in approving the 1996 program
which included some $3,500,000 for four newly proposed projects.  Based upon
additional information provided by GRI, the Commission concluded that GRI has
adequately supported inclusion of the four projects in question.  The
Commission did note that in future filings, GRI must be more thorough in
describing and justifying its research projects including firmly establishing
the ratepayer benefits of individual projects. The Commission also said that
beginning with GRI's next filing, it intends to increase its scrutiny of the
merits of the projects proposed as part of GRI's two-year plan.


9.               TEXAS EASTERN TRANSMISSION CORPORATION
                 (DOCKET NO. CP95-681-001)

                 The Commission approved a draft order denying Long Island
Lighting Company's request for rehearing of the Commission's October 11, 1995
order granting Texas Eastern a certificate to construct and operate minor
facilities necessary to upgrade the Gas City Compressor Station on the Lebanon
Lateral.  Among its findings, the Commission noted that while LILCO is correct
that there are costs associated with the expansion, in the final analysis, the
expansion project results in Lebanon Lateral rates that are less than they were
prior to the expansion.


10.              TRANSCONTINENTAL GAS PIPE LINE CORPORATION
                 (DOCKET NO. CP94-109-002)

                 The Commission approved an order amending Transco's 
certificate to construct its 1995/1996 Southeast Expansion Project to be 
implemented through a two-phase, incremental expansion of its main line 
pipeline in its Southeastern market area.  The amended certificate will 
increase the transportation capacity from 165,000 Mcf/d to 170,000 Mcf/d.  The 
increased capacity is attributable to the use of more horsepower than 
contained in the original application.


11.              TEXAS EASTERN TRANSMISSION CORPORATION
<PAGE>   44
                 (DOCKET NO. CP95-218-000)

                 The Commission approved Texas Eastern's February 22, 1995
petition for a declaratory order requesting the Commission to confirm that
Order No. 636 does not create a per se rule prohibiting interstate pipelines,
which have implemented Order No. 636 from entering into contracts for
transportation or storage capacity on other interstate pipelines.  In calling
this item up for discussion, Commissioner Santa noted that the market has now
evolved under Order No. 636 to the point that the anticompetitive concerns
surrounding this issue are not nearly as great as when Order No. 636 was first
being implemented.  The issue of pipelines holding capacity on upstream
pipelines will be decided on a case-by-case basis as the benefits are weighed
against the anticompetitive concerns.  The most significant anticompetitive
concern involves limiting the shippers choice.  With respect to rate treatment,
Commissioner Santa stated that the concerns regarding who pays are the same as
when a pipeline expands its facilities.  One of the benefits he noted regarding
a pipeline holding capacity on an upstream pipeline is the ability for the
shipper to deal with one entity vs two.


12.              NOTICE OF INQUIRY
                 (DOCKET NO. RM96-6)

                 The Commission announced it is issuing a notice of inquiry
(NOI) seeking comments on its merger policy under the Federal Power Act, which
has utilized the same criteria for evaluating the mergers of public utilities
for 30 years.  The NOI will give the Commission the benefit of public input on
how the Commission should evaluate proposed mergers in an open access
environment.  The NOI is being launched now so that the Commission will be in a
position to establish the new merger criteria once it completes action on the
final open access rule.  The open access rule is expected to become final this
spring.


13.              STATEMENT OF POLICY AND REQUEST FOR COMMENTS
                 (DOCKET NOS. RM95-6 and RM96-7)

                 The Commission issued its statement of policy on alternatives
to traditional cost-of-service ratemaking for natural gas pipelines.  The
Commission noted that the policy statement will provide the industry with
guidance by stating the criteria it will consider when evaluating proposals for
market-based rates, incentive rates, negotiated rates/recourse rates and other
alternatives to cost-of-service arrangements.

                 With respect to market-based rates, the policy statement
largely adopts the staff paper which accompanied the initial request for
comments issued one year ago, but contains more flexibility.  For example, the
Commission will not adopt a bright line threshold level for the HHI, below
which an applicant would automatically qualify for market-based rates, or above
which an applicant would be excluded from market-based rates.  Rather, the
Commission will use a .18 HHI as an indicator of the level of scrutiny to be
given to the applicant.  If the HHI is above .18, the applicant will get closer
scrutiny because the index indicates that the market is more concentrated and
the applicant may have significant market power.

                 For incentive rates the Commission revised its old policy, by
now allowing incentive rates to exceed cost-of-service levels if efficiency
gains are shared with customers.  The Commission is also eliminating
quantifiable benefits from its stated criteria.

                 The Commission will also allow pipelines to negotiate new
rates with their customers, but must file such rates with the Commission.  The
customers will have as a backstop, recourse rates available to them which are
based upon the pipelines existing cost-of-service.  With respect to allowing
negotiated terms and conditions of service along with a negotiated rate, the
Commission is requesting additional public comment before taking additional
action.  Parties interested in commenting have 60 days in which to respond.


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

The Commission will hold its next regularly scheduled Sunshine
Meeting on Wednesday,  February 14, 1996



                                          --------------------------------------
                                                     L. L. Willeke

<PAGE>   45



<PAGE>   1

                                                                    EXHIBIT 4-T

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




                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                        MARINE MIDLAND BANK, AS TRUSTEE


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


                          FIRST SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995


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


                   6.39% Debentures, Series Due November 2000





================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                    Indenture Section 
- -----------                                                                    ------------------
<S>                                                                                    <C>
310 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (a)(4)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
311 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
312 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
313 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
314 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
    (c)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
    (c)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
    (f)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
315 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
316 (a)(1)(A)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
    (a)(1)(B)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
317 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
318 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>

         *The 6.39% Debentures, Series Due November 2000, of The Columbia Gas
System, Inc.  (the "Company"), are issued under an indenture dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
to be further amended and supplemented by a First Supplemental Indenture dated
as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)


<TABLE>
         <S>                                                                                     <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
                                                                     
                                  ARTICLE ONE                        
                                  Definitions                        
                                  -----------
                                                                     
                                  ARTICLE TWO                        
                       6.39% Debentures Due November 2000            
                       ----------------------------------                                              

         SECTION 2.01     Creation of Series  . . . . . . . . . . . . . . . . . . . . . . . . . . 2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment  . . . . . . . 2
         SECTION 2.03     Denomination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.04     Redemption  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.05     Payment of Interest . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.06     Global Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.07     Additional Covenant . . . . . . . . . . . . . . . . . . . . . . . . . . 4

                                 ARTICLE THREE                     
                            Miscellaneous Provisions               
                            ------------------------                                       

         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . 6
                                                                                              
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
</TABLE>

EXHIBIT A--Form of 6.39% Debenture, Series Due November 2000





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

        (1)   The table of Contents is included herein for convenience only and
is not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995, between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995, (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures);and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "6.39% Debentures, Series Due
November 2000" (hereinafter called the Debentures Due November 2000) limited to
$310,876,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2000; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in





                                       1
<PAGE>   5
the form approved and having the terms and provisions so approved were duly
authorized and directed, and there was established for the Debentures Due
November 2000 a form substantially as in Exhibit A and all things necessary to
make the Debentures Due November 2000, when executed by the Company and
authenticated by the Trustee and issued under the Original Indenture, as
supplemented by this Supplemental Indenture, the valid, binding and legal
obligations of the Company in accordance with their terms and to make this
Supplemental Indenture a valid, binding and legal agreement, have been done and
performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2000 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2000 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                         DEBENTURES  DUE NOVEMBER 2000

         SECTION 2.01.  There shall be a series of Debentures designated as
"6.39% Debentures, Series Due November 2000" the aggregate principal amount of
which that may be outstanding being limited to $310,876,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2000 shall be substantially in the form
recited in Exhibit A.

         SECTION 2.02.  The Debentures  Due November 2000 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2000;
shall bear interest at the rate of 6.39% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28 to the holders of the Debentures ("Debentureholders") in
whose names such Debentures Due November 2000 are registered at the close of
business on or, as the case may be, next preceding such May 13 or November 13
or, if such date shall not be a Business Day, then the next preceding Business
Day (unless such Debenture has been called for redemption on a date fixed for
such redemption which is prior to such interest payment date), except that if
the Company shall default in the payment of any installment of interest on any
Debentures Due November 2000, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2000 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2000 may be





                                       2
<PAGE>   6
listed (such record date to be not less than five days prior to the date for
the payment of such defaulted interest); and shall be payable as to both
principal and interest in such coin or currency of the United States of America
as at the time of payment is legal tender for the payment of public and private
debts, at the corporate trust office of the Trustee in the Borough of
Manhattan, the City of New York.  Any such defaulted installment of interest on
any Debentures Due November 2000 that is not paid when due shall bear interest,
to the extent lawful, at the rate per annum borne by such Debentures plus 1%
per annum.

         SECTION 2.03.  The Debentures Due November 2000 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary Debentures Due November 2000 may be issued in
denominations as provided in Section 2.04 of the Original Indenture and shall
be exchangeable as provided in such temporary Debentures.

         SECTION 2.04.  The Debentures Due November 2000 are not subject to
redemption prior to maturity.

         SECTION 2.05.  Each of the Debentures Due November 2000 shall be dated
the date of authentication, and shall bear interest from the interest payment
date to which interest has been paid last preceding the date thereof (unless
the date thereof is an interest payment date to which interest has been paid,
in which case from the date thereof, or unless the date thereof is prior to May
28, 1996 in which case from November 28, 1995).  Notwithstanding the foregoing,
if the date of the Debentures Due November 2000 is after May 13 or November 13
as the case may be, and before the following May 28 or November 28 as the case
may be, such Debentures Due November 2000 shall bear interest from such May 28
or October 28 provided, however, that if and to the extent that the Company
shall default in the payment of interest due on such May 28 or October 28, such
Debentures Due November 2000 shall bear interest from the next preceding May 28
or October 28 to which interest has been paid or, if no interest has been paid,
from November 28, 1995.

         SECTION 2.06.  The Debentures Due November 2000 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November 2000 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November 2000 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November 2000 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November 2000 will not be entitled to have the Debentures Due
November 2000 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November 2000 in definitive form
and will not be considered the owners or





                                       3
<PAGE>   7
holders thereof under the Original Indenture and this Supplemental Indenture.
Unless and until it is exchanged in whole or in part for individual
certificates evidencing the Debentures Due November 2000 represented thereby,
the Global Security may not be transferred except as a whole by the Depositary
for the Global Security to a nominee of such Depositary or by a nominee of such
Depositary to such Depositary or another nominee of such Depositary or by the
Depositary or any nominee to a successor Depositary or any nominee of such
successor.

         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days, the
Company will issue definitive certificates in exchange for the Debentures Due
November 2000 represented by such Global Security.  In addition, the Company
may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November 2000 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture Securities (as described below)  are first issued (said earlier
date being the "Covenant Expiration Date"), the Company shall, subject to
applicable law and regulation, hold not less than $600 million principal amount
of First Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to
and entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an





                                       4
<PAGE>   8
amount equal to 150% of the amount by which $600 million exceeds the principal
amount of the Company's holdings of First Mortgage Bonds on the Trigger Date,
or (C) if subsequent to the Trigger Date, the principal amount of the Company's
holdings of First Mortgage Bonds falls below the amount of such holdings as of
the Trigger Date or below the lowest previous amount of such holdings
subsequent to the Trigger Date (any such date, a "Further Trigger Date") and
the Company retires (as described below) or has previously retired Company
Funded Debt in an amount equal to 150% of the amount by which $600 million
exceeds the principal amount of such holding on the Further Trigger Date, the
amount of such retirement with respect to any Further Trigger Date to be
measured for purposes of determining compliance with this provision as of the
sixtieth day after such Further Trigger Date.  The Company may "retire" Company
Funded Debt by any one or more of the following methods: (1) by cancellation of
Company Funded Debt which it acquires or reacquires, (2) by defeasance of
Company Funded Debt in accordance with the terms of such Company Funded Debt,
(3) by a bona fide tender offer for Company Funded Debt which, to the extent
such tender offer is for New Indenture Securities, is for principal amounts of
each series of New Indenture Securities that are proportionate to the relative
principal amount of such series outstanding on the relevant Trigger Date or
Further Trigger Date (a tender offer for any of the New Indenture Securities at
par will be deemed to retire an equivalent amount of Company Funded Debt,
irrespective of the amount of New Indenture Securities or the amount of any
series thereof actually tendered), or (4) by repayment or prepayment of Company
Funded Debt in accordance with its terms; provided, however, that repayment or
prepayment of Company Funded Debt under a banking loan facility shall not
constitute retirement of such Debt unless the Company shall have waived or
terminated any entitlement it may have thereunder to reborrow the amounts so
repaid or prepaid.  In connection with any such "retirement" of Company Funded
Debt, the Company (i) shall "retire" New Indenture Securities (treating the New
Indenture Securities as a single class) and other Company Funded Debt (treating
all such other Company Funded Debt as a single class) pro rata based on their
respective outstanding principal amounts on the relevant Trigger Date or
Further Trigger Date or (ii) may, at its option, "retire" a greater principal
amount of New Indenture Securities than is determined in accordance with the
foregoing clause (i).  The foregoing covenant shall not represent a limit on
the amount of Company Funded Debt or Funded Debt of TCO that may be outstanding
from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November 2000,
and (ii) the Company's 6.61% Debentures, Series Due November 2002, 6.80%
Debentures, Series Due November 2005, 7.05% Debentures, Series Due November
2007, 7.32% Debentures, Series Due November 2010, 7.42% Debentures, Series Due
November 2015 and 7.62% Debentures, Series Due November 2025, each issued under
the Original Indenture.





                                       5
<PAGE>   9
         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.

                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November 2000 shall be deemed to be a contract made under the laws of the
State of New York and for all purposes shall be construed in accordance with
and governed by the laws of said State.

         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       6
<PAGE>   10
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Assistant Vice Presidents, all as of November 28, 1995.


<TABLE>
<S>                                                         <C>
                                                            THE COLUMBIA GAS SYSTEM, INC.
                                                      
                                                      
Attest:   //s// C. M. Afshar                                by: //s// L. J. Bainter                                    
       -------------------------------------                   --------------------------------------------------------
               Secretary                                            L. J. Bainter, Treasurer
                                                      
                                                      
                                                      
                                                      
[CORPORATE SEAL]                                      
                                                      
                                                      
                                                      
                                                      
                                                      
                                                            MARINE MIDLAND BANK, as Trustee
                                                      
                                                      
Attest:   //s// Robert A. Conrad                            by:    //s// Metin Caner                                   
       -------------------------------------                   --------------------------------------------------------
             Assistant Vice President                               Metin Caner, Vice President





[CORPORATE SEAL]
</TABLE>





                                       7
<PAGE>   11
STATE OF DELAWARE)
                 ) ss:
New Castle County)


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.




                                          //s// Majorie A. Murray              
                                         --------------------------------------
                                         Notary Public
                                         
                                         
                                            12/6/96                            
                                         --------------------------------------
                                         My commission expires






                                       8
<PAGE>   12
STATE OF NEW YORK )
                  ) ss:
County of New York)



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.




                                          //s// S. C. Derenchuk            
                                         ------------------------------------
                                         Notary Public
                                           
                                           
                                            6/12/97                         
                                         ------------------------------------
                                         My commission expires






                                       9
<PAGE>   13
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   6.39% DEBENTURE, SERIES DUE NOVEMBER 2000
                             DUE NOVEMBER 28, 2000



                                                             CUSIP NO. 197648BY3

No.______________                                                $______________


         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2000 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 6.39% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996, in which case
from November 28, 1995 until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
after May 13 or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November





                                       10
<PAGE>   14
28 to which interest has been paid or, if no interest has been paid, from
November 28, 1995.  Any installment of interest on this Debenture that is not
paid when due shall bear interest at the rate borne by this Debenture plus 1%
per annum.

         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.


                                             THE COLUMBIA GAS SYSTEM, INC.

Dated:   November 28, 1995                   By:
                                                  ---------------------------
                                                         Treasurer
Attest:




                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.


                                             MARINE MIDLAND BANK, as Trustee
                                             
                                             By:
                                                 ---------------------------
                                                      Authorized Signatory






                                       11
<PAGE>   15
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   6.39% DEBENTURE, SERIES DUE NOVEMBER 2000
                             DUE NOVEMBER 28, 2000

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 6.39%
Debentures, Series Due November 2000 (herein called Debentures Due November
2000), all issued and to be issued under an Indenture dated as of November 28,
1995, as supplemented by one indenture supplemental thereto, including a First
Supplemental Indenture dated as of November 28, 1995, in which the Debentures
Due November 2000 are created and described, all executed between the Company
and Marine Midland Bank (herein called the Trustee), Trustee, to which the
Indenture and all indentures supplemental thereto (herein collectively called
the Indenture) reference is hereby made for a statement of the rights
thereunder of the Trustee and of the holders of the Debentures, and of the
duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2000 may not be redeemed prior to
maturity.

         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office





                                       12
<PAGE>   16
of the Trustee in said Borough of Manhattan, upon surrender and cancellation of
this Debenture, and, thereupon, a new fully registered Debenture or Debentures
Due November 2000 of the same aggregate principal amount shall be issued in
exchange therefor as provided in the Indenture.  The Company and the Trustee
may deem and treat the person in whose name this Debenture is registered as the
absolute owner hereof for the purpose of receiving payment of or on account of
the principal, premium, if any, and interest (except as stated in the first
paragraph on the face hereof) due hereon and for all other purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.

         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                       13

<PAGE>   1

                                                                    EXHIBIT 4-U


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




                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                        MARINE MIDLAND BANK, AS TRUSTEE


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


                         SECOND SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995


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


                  6.61% Debentures, Series Due November, 2002





================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                     Indenture Section 
- -----------                                                                     ------------------
<S>                                                                                    <C>
310 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (a)(4)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
311 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
312 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
313 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
314 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
    (c)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
    (c)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
    (f)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
315 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
316 (a)(1)(A)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
    (a)(1)(B)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
317 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
318 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>

            *The 6.61% Debentures, Series Due November 2002, of The Columbia
Gas System, Inc.  (the "Company"), are issued under an indenture dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
previously amended and supplemented by one indenture supplemental thereto and
as to be further amended and supplemented by a Second Supplemental Indenture
dated as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)


<TABLE>
         <S>                                                                                            <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
                                                                           
                                  ARTICLE ONE                              
                                  Definitions                              
                                  -----------
                                                                           
                                  ARTICLE TWO                              
                      6.61% Debentures  Due November 2002                  
                      -----------------------------------

         SECTION 2.01     Creation of Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment  . . . . . . . . . . 2
         SECTION 2.03     Denomination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.04     Redemption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.05     Payment of Interest.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.06     Global Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.07     Additional Covenant.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
                                                                        
                                 ARTICLE THREE                          
                            Miscellaneous Provisions                    
                            ------------------------

         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . . 6
                                                                                              
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
</TABLE>

EXHIBIT A--Form of 6.61% Debenture, Series Due November 2002





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

        (1)    The table of Contents is included herein for convenience only and
is not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995 between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995, (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures); and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "6.61% Debentures, Series Due
November 2002" (hereinafter called the Debentures Due November 2002) limited to
$281,530,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2002; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in the form approved and having the terms
and provisions so approved were duly authorized and directed, and there was
established for the Debentures Due November 2002 a form substantially as in
Exhibit A and all things necessary to make the Debentures Due November 2002,
when





                                       1
<PAGE>   5
executed by the Company and authenticated by the Trustee and issued under the
Original Indenture, as supplemented by this Supplemental Indenture, the valid,
binding and legal obligations of the Company in accordance with their terms and
to make this Supplemental Indenture a valid, binding and legal agreement, have
been done and performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2002 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2002 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                         DEBENTURES DUE NOVEMBER 2002

         SECTION 2.01.  There shall be a series of Debentures designated as
"6.61% Debentures, Series Due November 2002" the aggregate principal amount of
which that may be outstanding being limited to $281,530,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2002 shall be substantially in the form
recited in Exhibit A.

         SECTION 2.02.  The Debentures Due November 2002 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2002;
shall bear interest at the rate of 6.61% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28  to the holders of the Debentures ("Debentureholders") in
whose names such Debentures Due November 2002 are registered at the close of
business on or, as the case may be, next preceding such May 13 or November 13
or, if such date shall not be a Business Day, then the next preceding Business
Day (unless such Debenture has been called for redemption on a date fixed for
such redemption which is prior to such interest payment date), except that if
the Company shall default in the payment of any installment of interest on any
Debentures Due November 2002, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2002 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2002 may be listed (such record date to be not less
than five days prior to the date for the payment of such defaulted interest);
and shall be payable as to both principal and interest in such coin or currency
of the United States of America as at the time of payment is legal tender for
the payment of public and private debts, at the corporate trust office of the
Trustee in the Borough of Manhattan, the City of New York.  Any such defaulted
installment of interest on any Debentures Due





                                       2
<PAGE>   6
November 2002 that is not paid when due shall bear interest, to the extent
lawful, at the rate per annum (expressed in basis points) borne by such
Debentures plus 1% per annum.

         SECTION 2.03.  The Debentures Due November 2002 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary Debentures Due November 2002 may be issued in
denominations as provided in Section 2.04 of the Original Indenture and shall
be exchangeable as provided in such temporary Debentures.

         SECTION 2.04.  The Debentures Due November 2002 are not subject to
redemption prior to maturity.

         SECTION 2.05.  Each of the Debentures Due November 2002 shall be dated
the date of authentication, and shall bear interest from the interest payment
date to which interest has been paid last preceding the date thereof (unless
the date thereof is an interest payment date to which interest has been paid,
in which case from the date thereof, or unless the date thereof is prior to May
28, 1996 in which case from November 28, 1995).  Notwithstanding the foregoing,
if the date of the Debentures Due November 2002 is after May 13 or November 13,
as the case may be, and before the following May 28 or November 28, as the case
may be, such Debentures Due November 2002 shall bear interest from such May 28
or November 28; provided, however, that if and to the extent that the Company
shall default in the payment of interest due on such May 28 or November 28,
such Debenture Due November 2002 shall bear interest from the next preceding
May 28 or November 28 to which interest has been paid or, if no interest has
been paid, from November 28, 1995.

         SECTION 2.06.  The Debentures Due November 2002 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November 2002 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November 2002 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November 2002 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November 2002 will not be entitled to have the Debentures Due
November 2002 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November 2002 in definitive form
and will not be considered the owners or holders thereof under the Original
Indenture and this Supplemental Indenture.  Unless and until it is exchanged in
whole or in part for individual certificates evidencing the Debentures Due
November 2002 represented thereby, the Global Security may not be transferred
except as a whole by the Depositary for the Global Security to a nominee of
such Depositary or by a nominee of such Depositary to such Depositary or
another nominee of such Depositary or by the Depositary or any nominee to a
successor Depositary or any nominee of such successor.





                                       3
<PAGE>   7
         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days, the
Company will issue definitive certificates in exchange for the Debentures Due
November 2002 represented by such Global Security.  In addition, the Company
may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November 2002 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture Securities (as described below) are first issued (said earlier
date being the "Covenant Expiration Date"), the Company shall, subject to
applicable law and regulation, hold not less than $600 million principal amount
of First Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to
and entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an amount equal to 150% of the amount by which
$600 million exceeds the principal amount of the Company's holdings of First
Mortgage Bonds on the Trigger Date, or (C) if subsequent to the Trigger Date,
the principal amount of the Company's holdings of First Mortgage Bonds falls
below the amount of such holdings as of the Trigger Date or below the lowest
previous amount of such holdings subsequent to the Trigger Date (any such date,
a "Further Trigger Date") and the Company retires (as described below) or has
previously retired Company Funded Debt in an amount equal to 150% of the amount
by which $600 million exceeds the principal amount of such holding on the
Further Trigger Date, the amount of such retirement with respect to any Further
Trigger Date to be measured for purposes of determining compliance with this
provision as of the sixtieth day after such Further Trigger Date.  The Company
may "retire" Company





                                       4
<PAGE>   8
Funded Debt by any one or more of the following methods: (1) by cancellation of
Company Funded Debt which it acquires or reacquires, (2) by defeasance of
Company Funded Debt in accordance with the terms of such Company Funded Debt,
(3) by a bona fide tender offer for Company Funded Debt which, to the extent
such tender offer is for New Indenture Securities, is for principal amounts of
each series of New Indenture Securities that are proportionate to the relative
principal amount of such series outstanding on the relevant Trigger Date or
Further Trigger Date (a tender offer for any of the New Indenture Securities at
par will be deemed to retire an equivalent amount of Company Funded Debt,
irrespective of the amount of New Indenture Securities or the amount of any
series thereof actually tendered), or (4) by repayment or prepayment of Company
Funded Debt in accordance with its terms; provided, however, that repayment or
prepayment of Company Funded Debt under a banking loan facility shall not
constitute retirement of such Debt unless the Company shall have waived or
terminated any entitlement it may have thereunder to reborrow the amounts so
repaid or prepaid.  In connection with any such "retirement" of Company Funded
Debt, the Company (i) shall "retire" New Indenture Securities (treating the New
Indenture Securities as a single class) and other Company Funded Debt (treating
all such other Company Funded Debt as a single class) pro rata based on their
respective outstanding principal amounts on the relevant Trigger Date or
Further Trigger Date or (ii) may, at its option, "retire" a greater principal
amount of New Indenture Securities than is determined in accordance with the
foregoing clause (i).  The foregoing covenant shall not represent a limit on
the amount of Company Funded Debt or Funded Debt of TCO that may be outstanding
from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November 2002,
and (ii) the Company's 6.39% Debentures, Series Due November 2000, 6.80%
Debentures, Series Due November 2005, 7.05% Debentures, Series Due November
2007, 7.32% Debentures, Series Due November 2010, 7.42% Debentures, Series Due
November 2015 and 7.62% Debentures, Series Due November 2025, each issued under
the Original Indenture.

         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.

                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November 2002 shall be deemed to be a contract made under the laws of the
State of New York





                                       5
<PAGE>   9
and for all purposes shall be construed in accordance with and governed by the
laws of said State.

         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       6
<PAGE>   10
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Assistant Vice Presidents, all as of November 28, 1995.

<TABLE>
<S>                                                         <C>
                                                            THE COLUMBIA GAS SYSTEM, INC.
                                                       
                                                       
Attest:     //s//C. M. Afshar                               by: //s// L. J. Bainter                                 
       -------------------------------------                  -----------------------------------------------------
                     Secretary                                      L. J. Bainter, Treasurer
                                                       
                                                       
                                                       
                                                       
[CORPORATE SEAL]                                       
                                                       
                                                       
                                                       
                                                       
                                                       
                                                            MARINE MIDLAND BANK, as Trustee
                                                       
                                                       
Attest: //s// Robert A. Conrad                              by: //s// Metin Caner                                   
       -------------------------------------                   -----------------------------------------------------
             Assistant Vice President                               Metin Caner, Vice President





[CORPORATE SEAL]
</TABLE>





                                       7
<PAGE>   11
STATE OF DELAWARE)
                 ) ss:
New Castle County)


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.




                                                 //s// Majorie A. Murray       
                                             ----------------------------------
                                             Notary Public
                                             
                                             
                                                 12/5/96                       
                                             ----------------------------------
                                             My commission expires






                                       8
<PAGE>   12
STATE OF NEW YORK )
                  ) ss:
County of New York)



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.




                                                //s// S. C. Derenchuk          
                                             ----------------------------------
                                             Notary Public
                                             
                                             
                                                6/12/97                        
                                             ----------------------------------
                                             My commission expires






                                       9
<PAGE>   13
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   6.61% DEBENTURE, SERIES DUE NOVEMBER 2002
                             DUE NOVEMBER 28, 2002



                                                             CUSIP NO. 197648BZ0
                                                                           
No.______________                                                $______________


         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2002 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 6.61% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996, in which case
from November 28, 1995) until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
after May 13 or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.  Any installment of interest on
this Debenture that is not paid when due shall bear interest at the rate borne
by this Debenture plus 1% per annum.





                                       10
<PAGE>   14
         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.


                                             THE COLUMBIA GAS SYSTEM, INC.
                                             
Dated:   November 28, 1995                   By:  
                                                  ---------------------------
                                                         Treasurer
Attest:




                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.


                                             MARINE MIDLAND BANK, as Trustee

                                             By: 
                                                   ---------------------------
                                                       Authorized Signatory






                                       11
<PAGE>   15
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   6.61% DEBENTURE, SERIES DUE NOVEMBER 2002
                             DUE NOVEMBER 28, 2002

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 6.61%
Debentures, Series Due November 2002 (herein called Debentures Due November
2002) all issued and to be issued under an Indenture dated as of November 28,
1995, as supplemented by two indentures supplemental thereto, including a
Second Supplemental Indenture dated as of November 28, 1995, in which the
Debentures Due November 2002 are created and described, all executed between
the Company and Marine Midland Bank (herein called the Trustee), Trustee, to
which the  Indenture and all indentures supplemental thereto (herein
collectively called the Indenture) reference is hereby made for a statement of
the rights thereunder of the Trustee and of the holders of the Debentures, and
of the duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2002 may not be redeemed prior to
maturity.

         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office of the Trustee in said Borough of
Manhattan, upon surrender and cancellation of this Debenture, and, thereupon, a
new fully registered Debenture or Debentures Due November 2002 of the same
aggregate principal amount shall be issued in exchange therefor as provided in
the Indenture.  The Company and the Trustee may deem and treat the person in
whose name this Debenture is





                                       12
<PAGE>   16
registered as the absolute owner hereof for the purpose of receiving payment of
or on account of the principal, premium, if any, and interest (except as stated
in the first paragraph on the face hereof) due hereon and for all other
purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.

         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                       13

<PAGE>   1
                                                                   EXHIBIT 4-V

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

                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                        MARINE MIDLAND BANK, AS TRUSTEE


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


                          THIRD SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995


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



                   6.80% Debentures, Series Due November 2005

================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                        Indenture dated November 28,1995

<TABLE>
<CAPTION>
TIA Section                                                                     Indenture Section 
- -----------                                                                     ------------------
<S>                                                                                    <C>
310 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
    (a)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (a)(4)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
311 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
312 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
313 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
314 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
    (c)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
    (c)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
    (c)(3)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
    (f)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
315 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
    (c)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
    (d)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
    (e)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
316 (a)(1)(A)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
    (a)(1)(B)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
317 (a)(1)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
    (a)(2)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
    (b)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
318 (a)         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>

            *The 6.80% Debentures, Series Due November 2005, of The Columbia
Gas System, Inc.  (the "Company"), are issued under an indentures dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
previously amended and supplemented by two indentures supplemental thereto and
as to be further amended and supplemented by a Third Supplemental Indenture
dated as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)

<TABLE>
         <S>                                                                                                           <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1

                                  ARTICLE ONE
                                  Definitions
                                  -----------

                                  ARTICLE TWO
                      6.80% Debentures  Due November 2005
                      -----------------------------------

         SECTION 2.01     Creation of Series .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment. . . . . . . . . . . . . . . . . .  2
         SECTION 2.03     Denomination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.04     Redemption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.05     Payment of Interest.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.06     Global Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.07     Additional Covenant.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4

                                 ARTICLE THREE
                            Miscellaneous Provisions
                            ------------------------

         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6

         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8
</TABLE>

EXHIBIT A--Form of 6.80% Debenture, Series November 2005





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

     (1)   The table of Contents is included herein for convenience only and is
not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995 between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995, (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures); and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "6.80% Debentures, Series Due
November 2005" (hereinafter called the Debentures Due November 2005) limited to
$281,530,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2005; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in the form approved and having the terms
and provisions so approved were duly authorized and directed, and there was
established for the Debentures Due November 2005 a form substantially as in
Exhibit A and all things necessary to make the Debentures Due November 2005,
when





                                       1
<PAGE>   5
executed by the Company and authenticated by the Trustee and issued under the
Original Indenture, as supplemented by this Supplemental Indenture, the valid,
binding and legal obligations of the Company in accordance with their terms and
to make this Supplemental Indenture a valid, binding and legal agreement, have
been done and performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2005 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2005 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                         DEBENTURES  DUE NOVEMBER 2005

         SECTION 2.01.  There shall be a series of Debentures designated as
"6.80% Debentures, Series Due November 2005" the aggregate principal amount of
which that may be outstanding being limited to $281,530,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2005 shall be substantially in the form
recited in Exhibit A.

         SECTION 2.02.  The Debentures Due November 2005 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2005;
shall bear interest at the rate of 6.80% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28 to the holders of the Debentures ("Debentureholders") in
whose names such Debentures Due November 2005 are registered at the close of
business on or, as the case may be, next preceding such May 13 or November 13
or, if such date shall not be a Business Day, then the next preceding Business
Day (unless such Debenture has been called for redemption on a date fixed for
such redemption which is prior to such interest payment date), except that if
the Company shall default in the payment of any installment of interest on any
Debentures Due November 2005, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2005 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2005 may be listed (such record date to be not less
than five days prior to the date for the payment of such defaulted interest);
and shall be payable as to both principal and interest in such coin or currency
of the United States of America as at the time of payment is legal tender for
the payment of public and private debts, at the corporate trust office of the
Trustee in the Borough of Manhattan, the City of New York.  Any such defaulted
installment of interest on any Debentures Due





                                       2
<PAGE>   6
November 2005 that is not paid when due shall bear interest, to the extent
lawful, at the rate per annum borne by such Debentures plus 1% per annum.

         SECTION 2.03.  The Debentures Due November 2005 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary Debentures Due November 2005 may be issued in
denominations as provided in Section 2.04 of the Original Indenture and shall
be exchangeable as provided in such temporary Debentures.

         SECTION 2.04.  The Debentures Due November 2005 are not subject to
redemption prior to maturity.

         SECTION 2.05.  Each of the Debentures Due November 2005 shall be dated
the date of authentication, and shall bear interest from the interest payment
date to which interest has been paid last preceding the date thereof (unless
the date thereof is an interest payment date to which interest has been paid,
in which case from the date thereof, or unless the date thereof is prior to May
28, 1996 in which case from November 28, 1995).  Notwithstanding the foregoing,
if the date of the Debentures Due November 2005 is after May 13 or November 13,
as the case may be, and before the following May 28 or November 28, as the case
may be, such Debentures Due November 2005 shall bear interest from such May 28
or November 28; provided, however, that if and to the extent that the Company
shall default in the payment of interest due on such May 28 or November 28,
such Debentures Due November 2005 shall bear interest from the next preceding
May 28 or November 28 to which interest has been paid or, if no interest has
been paid, from November 28, 1995.

         SECTION 2.06.  The Debentures Due November 2005 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November 2005 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November 2005 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November 2005 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November 2005 will not be entitled to have the Debentures Due
November 2005 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November 2005 in definitive form
and will not be considered the owners or holders thereof under the Original
Indenture and this Supplemental Indenture.  Unless and until it is exchanged in
whole or in part for individual certificates evidencing the Debentures Due
November 2005 represented thereby, the Global Security may not be transferred
except as a whole by the Depositary for the Global Security to a nominee of
such Depositary or by a nominee of such Depositary to such Depositary or
another nominee of such Depositary or by the Depositary or any nominee to a
successor Depositary or any nominee of such successor.





                                       3
<PAGE>   7
         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days, the
Company will issue definitive certificates in exchange for the Debentures Due
November 2005 represented by such Global Security.  In addition, the Company
may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November 2005 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture (as described below) are first issued (said earlier date being
the "Covenant Expiration Date"), the Company shall, subject to applicable law
and regulation, hold not less than $600 million principal amount of First
Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to and
entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an amount equal to 150% of the amount by which
$600 million exceeds the principal amount of the Company's holdings of First
Mortgage Bonds on the Trigger Date, or (C) if subsequent to the Trigger Date,
the principal amount of the Company's holdings of First Mortgage Bonds falls
below the amount of such holdings as of the Trigger Date or below the lowest
previous amount of such holdings subsequent to the Trigger Date (any such date,
a "Further Trigger Date") and the Company retires (as described below) or has
previously retired Company Funded Debt in an amount equal to 150% of the amount
by which $600 million exceeds the principal amount of such holding on the
Further Trigger Date, the amount of such retirement with respect to any Further
Trigger Date to be measured for purposes of determining compliance with this
provision as of the sixtieth day after such Further Trigger Date.  The Company
may "retire" Company





                                       4
<PAGE>   8
Funded Debt by any one or more of the following methods: (1) by cancellation of
Company Funded Debt which it acquires or reacquires, (2) by defeasance of
Company Funded Debt in accordance with the terms of such Company Funded Debt,
(3) by a bona fide tender offer for Company Funded Debt which, to the extent
such tender offer is for New Indenture Securities, is for principal amounts of
each series of New Indenture Securities that are proportionate to the relative
principal amount of such series outstanding on the relevant Trigger Date or
Further Trigger Date (a tender offer for any of the New Indenture Securities at
par will be deemed to retire an equivalent amount of Company Funded Debt,
irrespective of the amount of New Indenture Securities or the amount of any
series thereof actually tendered), or (4) by repayment or prepayment of Company
Funded Debt in accordance with its terms; provided, however, that repayment or
prepayment of Company Funded Debt under a banking loan facility shall not
constitute retirement of such Debt unless the Company shall have waived or
terminated any entitlement it may have thereunder to reborrow the amounts so
repaid or prepaid.  In connection with any such "retirement" of Company Funded
Debt, the Company (i) shall "retire" New Indenture Securities (treating the New
Indenture Securities as a single class) and other Company Funded Debt (treating
all such other Company Funded Debt as a single class) pro rata based on their
respective outstanding principal amounts on the relevant Trigger Date or
Further Trigger Date or (ii) may, at its option, "retire" a greater principal
amount of New Indenture Securities than is determined in accordance with the
foregoing clause (i).  The foregoing covenant shall not represent a limit on
the amount of Company Funded Debt or Funded Debt of TCO that may be outstanding
from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November 2005,
and (ii) the Company's 6.39% Debentures, Series Due November 2000, 6.61%
Debentures, Series Due November 2002, 7.05% Debentures, Series Due November
2007, 7.32% Debentures, Series Due November 2010, 7.42% Debentures, Series Due
November 2015 and 7.62% Debentures, Series Due November 2025, each issued under
the Original Indenture.

         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.

                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November 2005 shall be deemed to be a contract made under the laws of the
State of New York





                                       5
<PAGE>   9
and for all purposes shall be construed in accordance with and governed by the
laws of said State.

         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       6
<PAGE>   10
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Assistant Vice Presidents, all as of November 28, 1995.


<TABLE>
<S>                                                         <C>
                                                            THE COLUMBIA GAS SYSTEM, INC.


Attest:   //s// C. M. Afshar                                by: //s// L. J. Bainter                                   
       -------------------------------------------------       -------------------------------------------------------
                       Secretary                                    L. J. Bainter, Treasurer




[CORPORATE SEAL]





                                                            MARINE MIDLAND BANK, as Trustee


Attest:    Robert A. Conrad                                 by:     //s// Metin Caner                                   
       --------------------------------------------            ---------------------------------------------------------
             Assistant Vice President                               Metin Caner, Vice President





[CORPORATE SEAL]
</TABLE>





                                       7
<PAGE>   11
STATE OF DELAWARE  )
                   ) ss:
New Castle County  )


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.



                                             Majorie A. Murray    
                                          ------------------------
                                          Notary Public
                                          
                                          
                                              12/5/96             
                                          ------------------------
                                          My commission expires





                                       8
<PAGE>   12
STATE OF NEW YORK  )
                   ) ss:
County of New York )



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.



                                              //s// S. C. Derenchuk 
                                          --------------------------
                                          Notary Public
                                          
                                          
                                              6/12/97               
                                          --------------------------
                                          My commission expires





                                       9
<PAGE>   13
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   6.80% DEBENTURE, SERIES DUE NOVEMBER 2005
                             DUE NOVEMBER 28, 2005
                                                   
                                                            CUSIP NO. 197648CA4
                                                   
No.______________                                               $______________

         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2005 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 6.80% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996, in which case
from November 28, 1995) until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
after May 13 or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.  Any installment of interest on
this Debenture that is not paid when due shall bear interest at the rate borne
by this Debenture plus 1% per annum.





                                       10
<PAGE>   14
         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.

                                    THE COLUMBIA GAS SYSTEM, INC.
                                    
Dated: November 28, 1995            By: 
                                        -------------------------
                                                       Treasurer
Attest:



                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.

                                    MARINE MIDLAND BANK, as Trustee
                                    
                                    By:      
                                       ----------------------------------
                                                     Authorized Signatory





                                       11
<PAGE>   15
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   6.80% DEBENTURE, SERIES DUE NOVEMBER 2005
                             DUE NOVEMBER 28, 2005

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 6.80%
Debentures, Series Due November 2005 (herein called Debentures Due November
2005), all issued and to be issued under an Indenture dated as of November 28,
1995, as supplemented by three indentures supplemental thereto, including a
Third Supplemental Indenture dated as of November 28, 1995, in which the
Debentures Due November 2005 are created and described, all executed between
the Company and Marine Midland Bank (herein called the Trustee), Trustee, to
which the  Indenture and all indentures supplemental thereto (herein
collectively called the Indenture) reference is hereby made for a statement of
the rights thereunder of the Trustee and of the holders of the Debentures, and
of the duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2005 may not be redeemed prior to
maturity.

         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office of the Trustee in said Borough of
Manhattan, upon surrender and cancellation of this Debenture, and, thereupon, a
new fully registered Debenture or Debentures Due November 2005 of the same
aggregate principal amount shall be issued in exchange therefor as provided in
the Indenture.  The Company and the Trustee may deem and treat the person in
whose name this Debenture is





                                       12
<PAGE>   16
registered as the absolute owner hereof for the purpose of receiving payment of
or on account of the principal, premium, if any, and interest (except as stated
in the first paragraph on the face hereof) due hereon and for all other
purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.

         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                       13

<PAGE>   1

                                                                    EXHIBIT 4-W

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


                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                        MARINE MIDLAND BANK, AS TRUSTEE


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


                         FOURTH SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995


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


                   7.05% Debentures, Series Due November 2007


================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                     Indenture Section 
- -----------                                                                     ------------------
   <S>                                                                                 <C>
   310 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (a)(4)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   311 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   312 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
   313 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
   314 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
       (c)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
       (c)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
       (f)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   315 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
   316 (a)(1)(A)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
       (a)(1)(B)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
   317 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
   318 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>


            *The 7.05% Debentures, Series Due November 2007, of The Columbia
Gas System, Inc.  (the "Company"), are issued under an indenture dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
previously amended and supplemented by three indentures supplemental thereto
and as to be further amended and supplemented by a Fourth Supplemental
Indenture dated as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)

<TABLE> 
         <S>                                                                                                    <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
                                                                                                               
                                                             ARTICLE ONE                                       
                                                             Definitions                                       
                                                             -----------                                       
                                                                                                               
                                                             ARTICLE TWO                                       
                                                  7.05% Debentures Due November 2007                           
                                                  ----------------------------------                           
                                                                                                               
         SECTION 2.01     Creation of Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment  . . . . . . . . . . . . . . 2
         SECTION 2.03     Denomination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.04     Redemption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.05     Payment of Interest.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.06     Global Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.07     Additional Covenant.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
                                                                                                               
                                                            ARTICLE THREE                                      
                                                       Miscellaneous Provisions                                
                                                       ------------------------                                
                                                                                                               
         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
                                                                                                               
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
</TABLE>    

EXHIBIT A--Form of 7.05% Debenture, Series November 2007





- ----------------------------
     (1)   The table of Contents is included herein for convenience only and 
is not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995, between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995 (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures); and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "7.05% Debentures, Series Due
November 2007" (hereinafter called the Debentures Due November 2007) limited to
$281,530,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2007; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in the form approved and having the terms
and provisions so approved were duly authorized and directed, and there was
established for the Debentures Due November 2007 a form substantially as in
Exhibit A and all things necessary to make the Debentures Due November 2007,
when executed by the Company and





                                       1
<PAGE>   5
authenticated by the Trustee and issued under the Original Indenture, as
supplemented by this Supplemental Indenture, the valid, binding and legal
obligations of the Company in accordance with their terms and to make this
Supplemental Indenture a valid, binding and legal agreement, have been done and
performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2007 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2007 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                          DEBENTURES DUE NOVEMBER 2007

         SECTION 2.01.  There shall be a series of Debentures designated as
"7.05% Debentures, Series Due November 2007" the aggregate principal amount of
which that may be outstanding being limited to $281,530,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2007 shall be substantially in the form
recited in Exhibit A.

         SECTION 2.02.  The Debentures Due November 2007 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2007;
shall bear interest at the rate of 7.05% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28 to the holders of the Debentures ("Debentureholders") in
whose names such Debentures Due November 2007 are registered at the close of
business on or, as the case may be, next preceding such May 13 or November 13
or, if such date shall not be a Business Day, then the next preceding Business
Day (unless such Debenture has been called for redemption on a date fixed for
such redemption which is prior to such interest payment date), except that if
the Company shall default in the payment of any installment of interest on any
Debentures Due November 2007, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2007 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2007 may be listed (such record date to be not less
than five days prior to the date for the payment of such defaulted interest);
and shall be payable as to both principal and interest in such coin or currency
of the United States of America as at the time of payment is legal tender for
the payment of public and private debts, at the corporate trust office of the
Trustee in the Borough of Manhattan, the City of New York.  Any such defaulted
installment of interest on any Debentures Due November 2007 that is not paid
when due shall bear interest, to the extent lawful, at the rate per annum borne
by such Debentures plus 1% per annum.





                                       2
<PAGE>   6
         SECTION 2.03.  The Debentures Due November 2007 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary Debentures Due November 2007 may be issued in
denominations as provided in Section 2.04 of the Original Indenture and shall
be exchangeable as provided in such temporary Debentures.

         SECTION 2.04.  The Debentures Due November 2007 may be redeemed prior
to maturity, at the election of the Company, as a whole at any time or in part
from time to time, in each case on or after November 28, 2005, at the
applicable redemption price or prices (expressed in percentages of principal
amount) set forth in the tabulation under the heading "Regular Redemption
Prices" in the form of Debentures Due November 2007 contained in Exhibit A to
this Supplemental Indenture, with accrued interest to the date fixed for
redemption.

         SECTION 2.05.  Each of the Debentures Due November 2007 shall be dated
the date of authentication, and shall bear interest from the interest payment
date to which interest has been paid last preceding the date thereof (unless
the date thereof is an interest payment date to which interest has been paid,
in which case from the date thereof, or unless the date thereof is prior to May
28, 1996 in which case from November 28, 1995).  Notwithstanding the foregoing,
if the date of the Debentures Due November 2007 is after May 13 or November 13,
as the case may be, and before the following May 28 or November 28, as the case
may be, such Debentures Due November 2007 shall bear interest from such May 28
or November 28; provided, however, that if and to the extent that the Company
shall default in the payment of interest due on such May 28 or November 28,
such Debentures Due November 2007 shall bear interest from the next preceding
May 28 or November 28 to which interest has been paid or, if no interest has
been paid, from November 28, 1995.

         SECTION 2.06.  The Debentures Due November 2007 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November 2007 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November 2007 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November 2007 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November 2007 will not be entitled to have the Debentures Due
November 2007 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November 2007 in definitive form
and will not be considered the owners or holders thereof under the Original
Indenture and this Supplemental Indenture.  Unless and until it is exchanged in
whole or in part for individual certificates evidencing the Debentures Due
November 2007 represented thereby, the Global Security may not be transferred
except as a whole by the Depositary for the Global Security to a nominee of
such Depositary or by a nominee of such Depositary to such Depositary or
another nominee of such Depositary or by the Depositary or any nominee to a
successor Depositary or any nominee of such successor.





                                       3
<PAGE>   7
         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days, the
Company will issue definitive certificates in exchange for the Debentures Due
November 2007 represented by such Global Security.  In addition, the Company
may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November 2007 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture Securities (as described below) are first issued (said earlier
date being the "Covenant Expiration Date"), the Company shall, subject to
applicable law and regulation, hold not less than $600 million principal amount
of First Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to
and entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an amount equal to 150% of the amount by which
$600 million exceeds the principal amount of the Company's holdings of First
Mortgage Bonds on the Trigger Date, or (C) if subsequent to the Trigger Date,
the principal amount of the Company's holdings of First Mortgage Bonds falls
below the amount of such holdings as of the Trigger Date or below the lowest
previous amount of such holdings subsequent to the Trigger Date (any such date,
a "Further Trigger Date") and the Company retires (as described below) or has
previously retired Company Funded Debt in an amount equal to 150% of the amount
by which $600 million exceeds the principal amount of such holding on the
Further Trigger Date, the amount of such retirement with respect to any Further
Trigger Date to be measured for purposes of determining compliance with this
provision as of the sixtieth day after such Further Trigger Date.  The Company
may "retire" Company Funded Debt by any one or more of the following methods:





                                       4
<PAGE>   8
(1) by cancellation of Company Funded Debt which it acquires or reacquires, (2)
by defeasance of Company Funded Debt in accordance with the terms of such
Company Funded Debt, (3) by a bona fide tender offer for Company Funded Debt
which, to the extent such tender offer is for New Indenture Securities, is for
principal amounts of each series of New Indenture Securities that are
proportionate to the relative principal amount of such series outstanding on
the relevant Trigger Date or Further Trigger Date (a tender offer for any of
the New Indenture Securities at par will be deemed to retire an equivalent
amount of Company Funded Debt, irrespective of the amount of New Indenture
Securities or the amount of any series thereof actually tendered), or (4) by
repayment or prepayment of Company Funded Debt in accordance with its terms;
provided, however, that repayment or prepayment of Company Funded Debt under a
banking loan facility shall not constitute retirement of such Debt unless the
Company shall have waived or terminated any entitlement it may have thereunder
to reborrow the amounts so repaid or prepaid.  In connection with any such
"retirement" of Company Funded Debt, the Company (i) shall "retire" New
Indenture Securities (treating the New Indenture Securities as a single class)
and other Company Funded Debt (treating all such other Company Funded Debt as a
single class) pro rata based on their respective outstanding principal amounts
on the relevant Trigger Date or Further Trigger Date or (ii) may, at its
option, "retire" a greater principal amount of New Indenture Securities than is
determined in accordance with the foregoing clause (i).  The foregoing covenant
shall not represent a limit on the amount of Company Funded Debt or Funded Debt
of TCO that may be outstanding from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November 2007,
and (ii) the Company's 6.39% Debentures, Series Due November 2000, 6.61%
Debentures, Series Due November 2002, 6.80% Debentures, Series Due November
2005, 7.32% Debentures,  Series Due November 2010, 7.42% Debentures, Series Due
November 2015 and 7.62% Debentures, Series Due November 2025, each issued under
the Original Indenture.

         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.

                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November 2007 shall be deemed to be a contract made under the laws of the
State of New York and for all purposes shall be construed in accordance with
and governed by the laws of said State.





                                       5
<PAGE>   9
         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       6
<PAGE>   10
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Assistant Vice Presidents, all as of November 28, 1995.


                                            THE COLUMBIA GAS SYSTEM, INC.


Attest:   //s// C.M. Afshar                 by:   //s// L. J. Bainter      
       -------------------------------         ---------------------------------
                  Secretary                             L. J. Bainter, Treasurer
                                            
                                            
                                            
                                            
[CORPORATE SEAL]                            
                                            
                                            
                                            
                                            
                                            
                                            MARINE MIDLAND BANK, as Trustee
                                            
                                            
Attest:   //s// R. A. Conrad                by:    //s// Metin Caner           
       -------------------------------         ---------------------------------
              Assistant Vice President               Metin Caner, Vice President





[CORPORATE SEAL]





                                       7
<PAGE>   11
STATE OF DELAWARE    )
                     ) ss:
New Castle County    )


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.



                                               //s// Majorie A. Murray  
                                            -----------------------------------
                                            Notary Public
                                            
                                            
                                              12/5/96                          
                                            -----------------------------------
                                            My commission expires





                                       8
<PAGE>   12
STATE OF NEW YORK  )
                   ) ss:
County of New York )



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.



                                                //s// S. C. Derenchuk          
                                            -----------------------------------
                                            Notary Public
                                            
                                            
                                                6/12/97                        
                                            -----------------------------------
                                            My commission expires
                                            




                                       9
<PAGE>   13
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.05% DEBENTURE, SERIES DUE NOVEMBER 2007
                             DUE NOVEMBER 28, 2007

                                                             CUSIP NO. 197648CB2

No.______________                                                $______________

         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2007 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 7.05% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996, in which case
from November 28, 1995) until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
after May 13 or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.  Any installment of interest on
this Debenture that is not paid when due shall bear interest at the rate borne
by this Debenture plus 1% per annum.





                                       10
<PAGE>   14
         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.

                                          THE COLUMBIA GAS SYSTEM, INC.


Dated:   November 28, 1995                By:     
                                              ------------------------
                                                     Treasurer
Attest:



                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.


                                          MARINE MIDLAND BANK, as Trustee

                                          By:     
                                             -------------------------
                                                Authorized Signatory





                                       11
<PAGE>   15
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.05% DEBENTURE, SERIES DUE NOVEMBER 2007
                             DUE NOVEMBER 28, 2007

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 7.05%
Debentures, Series Due November 2007 (herein called Debentures Due November
2007), all issued and to be issued under an Indenture dated as of November 28,
1995, as supplemented by four indentures supplemental thereto, including a
Fourth Supplemental Indenture dated as of November 28, 1995, in which the
Debentures Due November 2007 are created and described, all executed between
the Company and Marine Midland Bank (herein called the Trustee), Trustee, to
which the  Indenture and all indentures supplemental thereto (herein
collectively called the Indenture) reference is hereby made for a statement of
the rights thereunder of the Trustee and of the holders of the Debentures, and
of the duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2007 may be redeemed, prior to maturity,
at the election of the Company, as a whole at any time, or in part from time to
time, in each case on or after November 28, 2005, as provided in the Indenture,
at the redemption prices (expressed in percentages of principal amount) set
forth in the tabulation below under the heading "Regular Redemption Prices":





                                       12
<PAGE>   16
<TABLE>
<CAPTION>
                                If Redeemed During 12                                            Regular
                                    Months' Period                                              Redemption
                                      Commencing                                                  Prices
                                      ----------                                                  ------
                                   <S>                                                           <C>
                                   November 28, 2005                                             100.00%

                                   November 28, 2006                                             100.00%
</TABLE>


         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office of the Trustee in said Borough of
Manhattan, upon surrender and cancellation of this Debenture, and, thereupon, a
new fully registered Debenture or Debentures Due November 2007 of the same
aggregate principal amount shall be issued in exchange therefor as provided in
the Indenture.  The Company and the Trustee may deem and treat the person in
whose name this Debenture is registered as the absolute owner hereof for the
purpose of receiving payment of or on account of the principal, premium, if
any, and interest (except as stated in the first paragraph on the face hereof)
due hereon and for all other purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.

         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                       13

<PAGE>   1
                                                                    EXHIBIT 4-X


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


                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                         MARINE MIDLAND BANK AS TRUSTEE


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


                          FIFTH SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995



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



                  7.32 % Debentures, Series Due November 2010


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

<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                     Indenture Section 
- -----------                                                                     ------------------
   <S>                                                                                 <C>
   310 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (a)(4)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   311 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   312 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
   313 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
   314 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
       (c)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
       (c)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
       (f)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   315 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
   316 (a)(1)(A)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
       (a)(1)(B)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
   317 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
   318 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>

            *The 7.32% Debentures, Series Due November 2010, of The Columbia
Gas System, Inc.  (the "Company"), are issued under an indenture dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
previously amended and supplemented by four indentures supplemental thereto and
as to be further amended and supplemented by a Fifth Supplemental Indenture
dated as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)

<TABLE>
         <S>                                                                                          <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
                                                                                                   
                                                             ARTICLE ONE                           
                                                             Definitions                           
                                                             -----------                           
                                                                                                   
                                                             ARTICLE TWO                           
                                                  7.32% Debentures Due November 2010               
                                                 -----------------------------------               
                                                                                                   
         SECTION 2.01     Creation of Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment  . . . . . . . . . 2
         SECTION 2.03     Denomination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.04     Redemption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.05     Payment of Interest.  . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.06     Global Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.07     Additional Covenant.  . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
                                                                                                   
                                                            ARTICLE THREE                          
                                                       Miscellaneous Provisions                    
                                                       ------------------------                    
                                                                                                   
         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . 6
                                                                                                   
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
</TABLE>      

EXHIBIT A--Form of 7.32% Debenture, Series November 2010






- ---------------------------
     (1)   The table of Contents is included herein for convenience only and 
is not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995, between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995, (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures) and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "7.32% Debentures, Series Due
November 2010" (hereinafter called the Debentures Due November 2010) limited to
$281,530,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2010; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in the form approved and having the terms
and provisions so approved were duly authorized and directed, and there was
established for the Debentures Due November 2010 a form substantially as in
Exhibit A and all things necessary to make the Debentures Due November 2010,
when executed by the Company and authenticated by the Trustee and issued under
the Original Indenture, as supplemented by this Supplemental Indenture, the
valid, binding and legal obligations of the Company in accordance with





                                       1
<PAGE>   5
their terms and to make this Supplemental Indenture a valid, binding and legal
agreement, have been done and performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2010 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2010 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                          DEBENTURES DUE NOVEMBER 2010

         SECTION 2.01.  There shall be a series of Debentures designated as
"7.32% Debentures, Series Due November 2010" the aggregate principal amount of
which that may be outstanding being limited to $281,530,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2010 shall be substantially in the form r
ecited in Exhibit A.

         SECTION 2.02.  The Debentures Due November 2010 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2010;
shall bear interest at the rate of 7.32% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28 to the holders of Debentures ("Debentureholders") in whose
names such Debentures Due November 2010 are registered at the close of business
on or, as the case may be, next preceding such May 13 or November 13 or, if
such date shall not be a Business Day, then the next preceding Business Day
(unless such Debenture has been called for redemption on a date fixed for such
redemption which is prior to such interest payment date), except that if the
Company shall default in the payment of any installment of interest on any
Debentures Due November 2010, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2010 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2010 may be listed (such record date to be not less
than five days prior to the date for the payment of such defaulted interest);
and shall be payable as to both principal and interest in such coin or currency
of the United States of America as at the time of payment is legal tender for
the payment of public and private debts, at the corporate trust office of the
Trustee in the Borough of Manhattan, the City of New York.  Any such defaulted
installment of interest on any Debentures Due November 2010 that is not paid
when due shall bear interest, to the extent lawful, at the rate per annum borne
by such Debentures plus 1% per annum.

         SECTION 2.03.  The Debentures Due November 2010 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary





                                       2
<PAGE>   6
Debentures Due November 2010 may be issued in denominations as provided in
Section 2.04 of the Original Indenture and shall be exchangeable as provided in
such temporary Debentures.

         SECTION 2.04.  The Debentures Due November 2010 may be redeemed prior
to maturity, at the election of the Company, as a whole at any time or in part
from time to time, in each case on or after November 28, 2005, at the
applicable redemption price or prices (expressed in percentages of principal
amount) set forth in the tabulation under the heading "Regular Redemption
Prices" in the form of Debentures Due November 2010 contained in Exhibit A to
this Supplemental Indenture, with accrued interest to the date fixed for
redemption.

         SECTION 2.05.  Each of the Debentures Due November 2010 shall be dated
the date of authentication, and shall bear interest from the interest payment
date to which interest has been paid last preceding the date thereof (unless
the date thereof is an interest payment date to which interest has been paid,
in which case from the date thereof, or unless the date thereof is prior to May
28, 1996 in which case from November 28, 1995).  Notwithstanding the foregoing,
if the date of the Debentures Due November 2010 is after May 13 or November 13,
as the case may be, and before the following May 28 or November 28, as the case
may be, such Debentures Due November 2010 shall bear interest from such May 28
or November 28; provided, however, that if and to the extent that the Company
shall default in the payment of interest due on such May 28 or November 28,
such Debentures Due November 2010 shall bear interest from the next preceding
May 28 or November 28 to which interest has been paid or, if no interest has
been paid, from November 28, 1995.

         SECTION 2.06.  The Debentures Due November 2010 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November 2010 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November 2010 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November 2010 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November 2010 will not be entitled to have the Debentures Due
November 2010 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November 2010 in definitive form
and will not be considered the owners or holders thereof under the Original
Indenture and this Supplemental Indenture.  Unless and until it is exchanged in
whole or in part for individual certificates evidencing the Debentures Due
November 2010 represented thereby, the Global Security may not be transferred
except as a whole by the Depositary for the Global Security to a nominee of
such Depositary or by a nominee of such Depositary to such Depositary or
another nominee of such Depositary or by the Depositary or any nominee to a
successor Depositary or any nominee of such successor.

         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days,





                                       3
<PAGE>   7
the Company will issue definitive certificates in exchange for the Debentures
Due November 2010 represented by such Global Security.  In addition, the
Company may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November 2010 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture Securities (as described below) are first issued (said earlier
date being the "Covenant Expiration Date"), the Company shall, subject to
applicable law and regulation, hold not less than $600 million principal amount
of First Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to
and entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an amount equal to 150% of the amount by which
$600 million exceeds the principal amount of the Company's holdings of First
Mortgage Bonds on the Trigger Date, or (C) if subsequent to the Trigger Date,
the principal amount of the Company's holdings of First Mortgage Bonds falls
below the amount of such holdings as of the Trigger Date or below the lowest
previous amount of such holdings subsequent to the Trigger Date (any such date,
a "Further Trigger Date") and the Company retires (as described below) or has
previously retired Company Funded Debt in an amount equal to 150% of the amount
by which $600 million exceeds the principal amount of such holding on the
Further Trigger Date, the amount of such retirement with respect to any Further
Trigger Date to be measured for purposes of determining compliance with this
provision as of the sixtieth day after such Further Trigger Date.  The Company
may "retire" Company Funded Debt by any one or more of the following methods:
(1) by cancellation of Company Funded Debt which it acquires or reacquires, (2)
by defeasance of Company Funded Debt in accordance with the terms of such
Company Funded Debt, (3) by a bona fide tender offer for Company Funded Debt
which, to the extent such tender offer is for New Indenture Securities, is for
principal amounts of each series of New Indenture Securities that are
proportionate to the relative principal amount of such series outstanding





                                       4
<PAGE>   8
on the relevant Trigger Date or Further Trigger Date (a tender offer for any of
the New Indenture Securities at par will be deemed to retire an equivalent
amount of Company Funded Debt, irrespective of the amount of New Indenture
Securities or the amount of any series thereof actually tendered), or (4) by
repayment or prepayment of Company Funded Debt in accordance with its terms;
provided, however, that repayment or prepayment of Company Funded Debt under a
banking loan facility shall not constitute retirement of such Debt unless the
Company shall have waived or terminated any entitlement it may have thereunder
to reborrow the amounts so repaid or prepaid.  In connection with any such
"retirement" of Company Funded Debt, the Company (i) shall "retire" New
Indenture Securities (treating the New Indenture Securities as a single class)
and other Company Funded Debt (treating all such other Company Funded Debt as a
single class) pro rata based on their respective outstanding principal amounts
on the relevant Trigger Date or Further Trigger Date or (ii) may, at its
option, "retire" a greater principal amount of New Indenture Securities than is
determined in accordance with the foregoing clause (i).  The foregoing covenant
shall not represent a limit on the amount of Company Funded Debt or Funded Debt
of TCO that may be outstanding from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November 2010,
and (ii) the Company's 6.39% Debentures, Series Due November 2000, 6.61%
Debentures, Series Due November 2002, 6.80% Debentures, Series Due November
2005, 7.05% Debentures, Series Due November 2007, 7.42% Debentures, Series Due
November 2015 and 7.62% Debentures, Series Due November 2025, each issued under
the Original Indenture.

         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.

                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November 2010 shall be deemed to be a contract made under the laws of the
State of New York and for all purposes shall be construed in accordance with
and governed by the laws of said State.

         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       5
<PAGE>   9
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Vice Presidents, all as of November 28, 1995.


                                            THE COLUMBIA GAS SYSTEM, INC.


Attest:   //s// C. M. Afshar                by:    //s// L. J Bainter          
       --------------------------------        ---------------------------------
                 Secretary                           L. J. Bainter, Treasurer
                                                
                                                
                                                
                                                
[CORPORATE SEAL]                                
                                                
                                                
                                                
                                                
                                                
                                            MARINE MIDLAND BANK, as Trustee
                                                
                                                
Attest:    //s// Robert A. Conrad           by:   //s// Metin Caner            
       --------------------------------        ---------------------------------
             Assistant Vice President              Metin Caner, Vice President
                                                




[CORPORATE SEAL]





                                       6
<PAGE>   10
STATE OF DELAWARE   )
                    ) ss:
New Castle County   )


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.


                                                //s// Majorie A. Murray      
                                            ---------------------------------
                                            Notary Public
                                    
                                    
                                              12/5/96                        
                                            ---------------------------------
                                            My commission expires
                                    




                                       7
<PAGE>   11
STATE OF NEW YORK  )
                   ) ss:
County of New York )



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.



                                               //s// S. C. Derenchuk  
                                            -----------------------------------
                                            Notary Public


                                               6/12/97                         
                                            -----------------------------------
                                            My commission expires





                                       8
<PAGE>   12
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.32% DEBENTURE, SERIES DUE NOVEMBER 2010
                             DUE NOVEMBER 28, 2010

                                                             CUSIP NO. 197648CC0

No.______________                                                $______________

         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2010 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 7.32% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996, in which case
from November 28, 1995) until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
after May 13 or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.  Any installment of interest on
this Debenture that is not paid when due shall bear interest at the rate borne
by this Debenture plus 1% per annum.





                                       9
<PAGE>   13
         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.

                                                 THE COLUMBIA GAS SYSTEM, INC.

Dated:   November 28, 1995                  By:
                                                 -------------------------------
                                                             Treasurer
Attest:



                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.


                                            MARINE MIDLAND BANK, as Trustee

                                            By:  
                                                 -------------------------------
                                                       Authorized Signatory





                                       10
<PAGE>   14
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.32 % DEBENTURE, SERIES DUE NOVEMBER 2010
                             DUE NOVEMBER 28, 2010

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 7.32%
Debentures, Series Due November 2010 (herein called Debentures Due November
2010 all issued and to be issued under an Indenture dated as of November 28,
1995 as supplemented by five indentures supplemental thereto, including a Fifth
Supplemental Indenture dated as of November 28, 1995 in which the Debentures
Due November 2010 are created and described, all executed between the Company
and Marine Midland Bank (herein called the Trustee), Trustee, to which the
Indenture and all indentures supplemental thereto (herein collectively called
the Indenture) reference is hereby made for a statement of the rights
thereunder of the Trustee and of the holders of the Debentures, and of the
duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2010 may be redeemed, prior to maturity,
at the election of the Company, as a whole at any time, or in part from time to
time, in each case on or after November 28, 2005, as provided in the Indenture,
at the redemption prices (expressed in percentages of principal amount) set
forth in the tabulation below under the heading "Regular Redemption Prices":





                                       11
<PAGE>   15
<TABLE>
<CAPTION>
                                  If Redeemed During 12                                          Regular
                                      Months' Period                                            Redemption
                                        Commencing                                                Prices
                                        ----------                                                ------
                                   <S>                                                           <C>
                                   November 28, 2005                                             100.00%

                                   November 28, 2006                                             100.00%

                                   November 28, 2007                                             100.00%

                                   November 28, 2008                                             100.00%

                                   November 28, 2009                                             100.00%
</TABLE>


         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office of the Trustee in said Borough of
Manhattan, upon surrender and cancellation of this Debenture, and, thereupon, a
new fully registered Debenture or Debentures Due November 2010 of the same
aggregate principal amount shall be issued in exchange therefor as provided in
the Indenture.  The Company and the Trustee may deem and treat the person in
whose name this Debenture is registered as the absolute owner hereof for the
purpose of receiving payment of or on account of the principal, premium, if
any, and interest (except as stated in the first paragraph on the face hereof)
due hereon and for all other purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.

         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                       12

<PAGE>   1
                                                                    EXHIBIT 4-Y

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


                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                        MARINE MIDLAND BANK, AS TRUSTEE


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


                          SIXTH SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995



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



                  7.42 % Debentures, Series Due November 2015


================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                     Indenture Section 
- -----------                                                                     ------------------
   <S>                                                                                 <C>
   310 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (a)(4)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   311 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   312 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
   313 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
   314 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
       (c)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
       (c)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
       (f)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   315 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
   316 (a)(1)(A)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
       (a)(1)(B)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
   317 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
   318 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>

            *The 7.42% Debentures, Series Due November 2015, of The Columbia
Gas System, Inc.  (the "Company"), are issued under an indenture dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
previously amended and supplemented by five indentures supplemental thereto and
as to be further amended and supplemented by a Sixth Supplemental Indenture
dated as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)

<TABLE>
         <S>                                                                                                        <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

<CAPTION>                                                                                                                 
                                                             ARTICLE ONE                                         
                                                             Definitions                                         
                                                             -----------                                         
                                                                                                                 
                                                             ARTICLE TWO                                         
                                                  7.42% Debentures Due November 2015                             
                                                  ----------------------------------                             
         <S>                                                                                                       <C> 
         SECTION 2.01     Creation of Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment  . . . . . . . . . . . . . . . . 2
         SECTION 2.03     Denomination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.04     Redemption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.05     Payment of Interest.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.06     Global Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
         SECTION 2.07     Additional Covenant.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
                                                                                                                 
                                                            ARTICLE THREE                                        
                                                       Miscellaneous Provisions                                  
                                                       ------------------------                                  
                                                                                                                 
         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
                                                                                                                 
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
</TABLE>  

EXHIBIT A--Form of 7.42% Debenture, Series Due November 2015





- ---------------------------
     (1)   The table of Contents is included herein for convenience only and 
is not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995 between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995, (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures); and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "7.42% Debentures, Series Due
November 2015" (hereinafter called the Debentures Due November 2015) limited to
$281,530,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2015; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in the form approved and having the terms
and provisions so approved were duly authorized and directed, and there was
established for the Debentures Due November 2015 a form substantially as in
Exhibit A and all things necessary to make the Debentures Due November 2015,
when executed by the Company and authenticated by the Trustee and issued under
the Original Indenture, as supplemented by this Supplemental Indenture, the
valid, binding and legal obligations of the Company in accordance with





                                       1
<PAGE>   5
their terms and to make this Supplemental Indenture a valid, binding and legal
agreement, have been done and performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2015 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2015 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                          DEBENTURES DUE NOVEMBER 2015

         SECTION 2.01.  There shall be a series of Debentures designated as
"7.42% Debentures, Series Due November 2015" the aggregate principal amount of
which that may be outstanding being limited to $281,530,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2015 shall be substantially in the form 
recited in Exhibit A.

         SECTION 2.02.  The Debentures Due November 2015 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2015;
shall bear interest at the rate of 7.42% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28 to the holders of the Debentures ("Debentureholders") in
whose names such Debentures Due November 2015 are registered at the close of
business on or, as the case may be, next preceding such May 13 or November 13
or, if such date shall not be a Business Day, then the next preceding Business
Day (unless such Debenture has been called for redemption on a date fixed for
such redemption which is prior to such interest payment date), except that if
the Company shall default in the payment of any installment of interest on any
Debentures Due November 2015, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2015 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2015 may be listed (such record date to be not less
than five days prior to the date for the payment of such defaulted interest);
and shall be payable as to both principal and interest in such coin or currency
of the United States of America as at the time of payment is legal tender for
the payment of public and private debts, at the corporate trust office of the
Trustee in the Borough of Manhattan, the City of New York.  Any such defaulted
installment of interest on any Debentures Due November 2015 that is not paid
when due shall bear interest, to the extent lawful, at the rate per annum borne
by such Debentures plus 1% per annum.

         SECTION 2.03.  The Debentures Due November  2015 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary





                                       2
<PAGE>   6
Debentures Due November  2015 may be issued in denominations as provided in
Section 2.04 of the Original Indenture and shall be exchangeable as provided in
such temporary Debentures.

         SECTION 2.04.  The Debentures Due November  2015 may be redeemed prior
to maturity, at the election of the Company, as a whole at any time or in part
from time to time, in each case on or after November 28, 2005, at the
applicable redemption price or prices (expressed in percentages of principal
amount) set forth in the tabulation under the heading "Regular Redemption
Prices" in the form of Debentures Due November 2015 contained in Exhibit A to
this Supplemental Indenture, with accrued interest to the date fixed for
redemption.

         SECTION 2.05.  Each of the Debentures Due November  2015 shall be
dated the date of authentication, and shall bear interest from the interest
payment date to which interest has been paid last preceding the date thereof
(unless the date thereof is an interest payment date to which interest has been
paid, in which case from the date thereof, or unless the date thereof is prior
to May 28, 1996  in which case from November 28, 1995).  Notwithstanding the
foregoing, if the date of the Debentures Due November 2015 is after May 13 or
November 13, as the case may be, and before the following May 28 or November
28, as the case may be, such Debentures Due November  2015 shall bear interest
from such May 28 or November 28; provided, however, that if and to the extent
that the Company shall default in the payment of interest due on such May 28 or
November 28, such Debentures Due November 2015 shall bear interest from the
next preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.

         SECTION 2.06.  The Debentures Due November  2015 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November  2015 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November  2015 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November  2015 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November  2015 will not be entitled to have the Debentures Due
November  2015 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November  2015 in definitive form
and will not be considered the owners or holders thereof under the Original
Indenture and this Supplemental Indenture.  Unless and until it is exchanged in
whole or in part for individual certificates evidencing the Debentures Due
November  2015 represented thereby, the Global Security may not be transferred
except as a whole by the Depositary for the Global Security to a nominee of
such Depositary or by a nominee of such Depositary to such Depositary or
another nominee of such Depositary or by the Depositary or any nominee to a
successor Depositary or any nominee of such successor.

         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days,





                                       3
<PAGE>   7
the Company will issue definitive certificates in exchange for the Debentures
Due November  2015 represented by such Global Security.  In addition, the
Company may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November  2015 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture Securities (as described below) are first issued (said earlier
date being the "Covenant Expiration Date"), the Company shall, subject to
applicable law and regulation, hold not less than $600 million principal amount
of First Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to
and entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an amount equal to 150% of the amount by which
$600 million exceeds the principal amount of the Company's holdings of First
Mortgage Bonds on the Trigger Date, or (C) if subsequent to the Trigger Date,
the principal amount of the Company's holdings of First Mortgage Bonds falls
below the amount of such holdings as of the Trigger Date or below the lowest
previous amount of such holdings subsequent to the Trigger Date (any such date,
a "Further Trigger Date") and the Company retires (as described below) or has
previously retired Company Funded Debt in an amount equal to 150% of the amount
by which $600 million exceeds the principal amount of such holding on the
Further Trigger Date, the amount of such retirement with respect to any Further
Trigger Date to be measured for purposes of determining compliance with this
provision as of the sixtieth day after such Further Trigger Date.  The Company
may "retire" Company Funded Debt by any one or more of the following methods:
(1) by cancellation of Company Funded Debt which it acquires or reacquires, (2)
by defeasance of Company Funded Debt in accordance with the terms of such
Company Funded Debt, (3) by a bona fide tender offer for Company Funded Debt
which, to the extent such tender offer is for New Indenture Securities, is for
principal amounts of each series of New Indenture Securities that are
proportionate to the relative principal amount of such series outstanding





                                       4
<PAGE>   8
on the relevant Trigger Date or Further Trigger Date (a tender offer for any of
the New Indenture Securities at par will be deemed to retire an equivalent
amount of Company Funded Debt, irrespective of the amount of New Indenture
Securities or the amount of any series thereof actually tendered), or (4) by
repayment or prepayment of Company Funded Debt in accordance with its terms;
provided, however, that repayment or prepayment of Company Funded Debt under a
banking loan facility shall not constitute retirement of such Debt unless the
Company shall have waived or terminated any entitlement it may have thereunder
to reborrow the amounts so repaid or prepaid.  In connection with any such
"retirement" of Company Funded Debt, the Company (i) shall "retire" New
Indenture Securities (treating the New Indenture Securities as a single class)
and other Company Funded Debt (treating all such other Company Funded Debt as a
single class) pro rata based on their respective outstanding principal amounts
on the relevant Trigger Date or Further Trigger Date or (ii) may, at its
option, "retire" a greater principal amount of New Indenture Securities than is
determined in accordance with the foregoing clause (i).  The foregoing covenant
shall not represent a limit on the amount of Company Funded Debt or Funded Debt
of TCO that may be outstanding from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November
2015, and (ii) the Company's 6.39% Debentures, Series Due November  2000, 6.61%
Debentures, Series Due November  2002, 6.80% Debentures, Series Due November
2005, 7.05% Debentures, Series Due November 2007, 7.32% Debentures, Series Due
November  2010 and 7.62% Debentures, Series Due November  2025, each issued
under the Original Indenture.

         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.

                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November  2015 shall be deemed to be a contract made under the laws of the
State of New York and for all purposes shall be construed in accordance with
and governed by the laws of said State.

         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       5
<PAGE>   9
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank  has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Assistant Vice Presidents, all as of November 28, 1995.


                                            THE COLUMBIA GAS SYSTEM, INC.


Attest:     //s// C. M. Afshar              by:   //s// L. J. Bainter      
       ----------------------------------      --------------------------------
                   Secretary                         L. J. Bainter, Treasurer
                                       
                                       
                                       
                                       
[CORPORATE SEAL]                       
                                       
                                       
                                       
                                       
                                       
                                            MARINE MIDLAND BANK, as Trustee
                                       
                                       
Attest:    //s// Robert A. Conrad           by:     //s// Metin Caner          
       --------------------------------        --------------------------------
             Assistant Vice President               Metin Caner, Vice President
                                            
                                            



[CORPORATE SEAL]





                                       6
<PAGE>   10
STATE OF DELAWARE   )
                    ) ss:
New Castle County   )


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.


                                            
                                               //s// Majorie A. Murray 
                                            -----------------------------------
                                            Notary Public
                                            
                                            
                                              12/5/96                          
                                            -----------------------------------
                                            My commission expires
                                            




                                       7
<PAGE>   11
STATE OF NEW YORK   )
                    ) ss:
County of New York  )



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.



                                                 //s// S. C. Derenchuk         
                                            -----------------------------------
                                            Notary Public
                                            
                                            
                                                6/12/97                        
                                            -----------------------------------
                                            My commission expires





                                       8
<PAGE>   12
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.42% DEBENTURE, SERIES DUE NOVEMBER  2015
                             DUE NOVEMBER 28, 2015

                                                             CUSIP NO. 197648CD8

No.______________                                                $______________

         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2015 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 7.42% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996 in which case
from November 28, 1995) until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
May 13, or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.  Any installment of interest on
this Debenture that is not paid when due shall bear interest at the rate borne
by this Debenture plus 1% per annum.





                                       9
<PAGE>   13
         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.

                                            THE COLUMBIA GAS SYSTEM, INC.
                                            
Dated:   November 28, 1995                  By:          
                                                 ------------------------------
                                                             Treasurer
                                            
                                            
Attest:                                     
         -----------------------------
                                            
                                            

                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.


                                            MARINE MIDLAND BANK, as Trustee
                                            
                                            
                                            By:                                
                                                 ------------------------------
                                                      Authorized Signatory
                                            
                                            
                                            
                                            

                                       10
<PAGE>   14
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.42% DEBENTURE, SERIES DUE NOVEMBER 2015
                             DUE NOVEMBER 28, 2015

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 7.42%
Debentures, Series Due November 2015 (herein called Debentures Due November
2015) all issued and to be issued under an Indenture dated as of November 28,
1995, as supplemented by six indentures supplemental thereto, including a Sixth
Supplemental Indenture dated as of November 28, 1995, in which the Debentures
Due November 2015 are created and described, all executed between the Company
and Marine Midland Bank (herein called the Trustee), Trustee, to which the
Indenture and all indentures supplemental thereto (herein collectively called
the Indenture) reference is hereby made for a statement of the rights
thereunder of the Trustee and of the holders of the Debentures, and of the
duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2015 may be redeemed, prior to maturity,
at the election of the Company, as a whole at any time, or in part from time to
time, in each case on or after November 28, 2005, as provided in the Indenture,
at the redemption prices (expressed in percentages of principal amount) set
forth in the tabulation below under the heading "Regular Redemption Prices":





                                       11
<PAGE>   15
<TABLE>
<CAPTION>
                                If Redeemed During 12                                            Regular
                                    Months' Period                                              Redemption
                                      Commencing                                                  Prices
                                      ----------                                                  ------
                                   <S>                                                           <C>
                                   November 28, 2005                                             102.12%

                                   November 28, 2006                                             101.59%

                                   November 28, 2007                                             101.06%

                                   November 28, 2008                                             100.53%

                                   November 28, 2009                                             100.00%

                                   November 28, 2010                                             100.00%

                                   November 28, 2011                                             100.00%

                                   November 28, 2012                                             100.00%

                                   November 28, 2013                                             100.00%

                                   November 28, 2014                                             100.00%
</TABLE>



         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office of the Trustee in said Borough of
Manhattan, upon surrender and cancellation of this Debenture, and, thereupon, a
new fully registered Debenture or Debentures Due November 2015 of the same
aggregate principal amount shall be issued in exchange therefor as provided in
the Indenture.  The Company and the Trustee may deem and treat the person in
whose name this Debenture is registered as the absolute owner hereof for the
purpose of receiving payment of or on account of the principal, premium, if
any, and interest (except as stated in the first paragraph on the face hereof)
due hereon and for all other purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.





                                       12
<PAGE>   16
         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                      13

<PAGE>   1

                                                                    EXHIBIT 4-Z

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


                         THE COLUMBIA GAS SYSTEM, INC.

                                      AND

                        MARINE MIDLAND BANK, AS TRUSTEE


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


                         SEVENTH SUPPLEMENTAL INDENTURE


                         Dated as of November 28, 1995

             Supplementing Indenture Dated as of November 28, 1995


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


                  7.62% Debentures, Series Due November 2025


================================================================================
<PAGE>   2
(This Cross Reference Sheet, showing the location in the indenture of the
provisions inserted pursuant to Sections 310 to 318(a), inclusive of the Trust
Indenture Act of 1939, is being furnished pursuant to Item 601 of Regulation
S-K and is not to be construed as part of the indenture.)

                             CROSS-REFERENCE TABLE
- --------------------------------------------------------------------------------
         The Columbia Gas System, Inc. and Marine Midland Bank, Trustee
                       Indenture dated November 28, 1995

<TABLE>
<CAPTION>
TIA Section                                                                     Indenture Section 
- -----------                                                                     ------------------
   <S>                                                                                 <C>
   310 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.10
       (a)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (a)(4)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08, 6.10, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   311 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   312 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.03
   313 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06, 11.02
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
   314 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3.05, 11.02
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.06
       (c)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.04
       (c)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.02, 11.04
       (c)(3)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.05
       (f)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
   315 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(b)
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05, 11.02
       (c)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(a)
       (d)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.01(c)
       (e)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.11
   316 (a)(1)(A)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.05
       (a)(1)(B)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.04
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N.A.
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.07
   317 (a)(1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.08
       (a)(2)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5.09
       (b)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
   318 (a)      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11.01
</TABLE>

            *The 7.62% Debentures, Series Due November 2025, of The Columbia
Gas System, Inc.  (the "Company"), are issued under an indenture dated as of
November 28, 1995 between the Company and Marine Midland Bank, as Trustee, as
previously amended and supplemented by six indentures supplemental thereto and
as to be further amended and supplemented by a Seventh Supplemental Indenture
dated as of November 28, 1995.
<PAGE>   3
                              TABLE OF CONTENTS(1)

<TABLE>
         <S>                                                                                                     <C>
         PARTIES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1
         RECITALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1
                                                                                                                
                                                             ARTICLE ONE                                        
                                                             Definitions                                        
                                                             -----------                                        
                                                                                                                
                                                             ARTICLE TWO                                        
                                                  7.62% Debentures Due November 2025                            
                                                 -----------------------------------                            
                                                                                                                
         SECTION 2.01     Creation of Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2
         SECTION 2.02     Date of Issue, Maturity, Interest Rate, Place of Payment  . . . . . . . . . . . . . .  2
         SECTION 2.03     Denomination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.04     Redemption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.05     Payment of Interest.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.06     Global Securities.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
         SECTION 2.07     Additional Covenant.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4
                                                                                                                
                                                            ARTICLE THREE                                       
                                                       Miscellaneous Provisions                                 
                                                       ------------------------                                 
                                                                                                                
         SECTION 3.01     Execution in Counterparts.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
         SECTION 3.02     Governing Law.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
         SECTION 3.03     Responsibility of Trustee.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
                                                                                                                
         TESTIMONIUM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7
         EXECUTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7
         ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8
</TABLE> 

EXHIBIT A--Form of 7.62% Debenture, Series November 2025





- ------------------------------
     (1)   The table of Contents is included herein for convenience only and 
is not to be considered a part of the Supplemental Indenture.
<PAGE>   4
                                    PARTIES

           SUPPLEMENTAL INDENTURE dated as of November 28, 1995, between THE
COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter called the
Company), and MARINE MIDLAND BANK, a banking corporation and trust company
organized and existing under the laws of the State of New York (hereinafter
called the "Trustee") (the "Supplemental Indenture").

                                    RECITALS

         WHEREAS the Company has heretofore executed and delivered to the
Trustee a certain indenture dated as of November 28, 1995, (hereinafter called
the Original Indenture), providing for the issuance of senior debt securities
of the Company, unlimited in aggregate principal amount (hereinafter called the
Debentures); and

         WHEREAS ARTICLE TWO of the Original Indenture provides, among other
things, that the Debentures may be issued in one or more series, the Debentures
of each series maturing on such dates and bearing interest at such rates and
having such other terms and provisions as the Board of Directors of the Company
may determine prior to the authentication thereof; and

         WHEREAS ARTICLES TWO and EIGHT of the Original Indenture provide,
among other things, that the Company and the Trustee may from time to time
enter into indentures supplemental thereto for the purpose of setting forth the
terms and provisions of any one or more series of Debentures and for any
purpose not inconsistent with the terms of the Original Indenture, including
such additional covenants not inconsistent with the provisions of the Original
Indenture as may be agreed upon by the Company and the Trustee, or for the
purpose of curing any ambiguity or of curing, correcting or supplementing any
defective or inconsistent provision of the Original Indenture; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined,
under and in accordance with the provisions of the Original Indenture, to
create a new series of Debentures to be known as "7.62% Debentures, Series Due
November 2025" (hereinafter called the Debentures Due November 2025) limited to
$281,530,000.00 in aggregate principal amount, the further terms and provisions
of which are hereinafter set forth; and

         WHEREAS the Company, pursuant to resolutions duly adopted by its Board
of Directors at a meeting of said Board duly called and held, has determined
that it is advisable to amend and supplement the Original Indenture by
providing for a record date in connection with the payment of interest to the
holders of Debentures Due November 2025; and

         WHEREAS at or pursuant to resolutions adopted at said meeting of the
Board of Directors of the Company the form, terms and provisions of this
Supplemental Indenture were duly approved and the execution and delivery by the
Company of a supplemental indenture in the form approved and having the terms
and provisions so approved were duly authorized and directed, and there was
established for the Debentures Due November 2025 a form substantially as in
Exhibit A and all things necessary to make the Debentures Due November 2025,
when





                                       1
<PAGE>   5
executed by the Company and authenticated by the Trustee and issued under the
Original Indenture, as supplemented by this Supplemental Indenture, the valid,
binding and legal obligations of the Company in accordance with their terms and
to make this Supplemental Indenture a valid, binding and legal agreement, have
been done and performed;

         NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order
to set forth the terms and provisions of the Debentures Due November 2025 and
for and in consideration of the premises and of the acceptance or purchase of
the Debentures Due November 2025 by the holders thereof, the Company covenants
and agrees with the Trustee as follows:

                                  ARTICLE ONE
                                  DEFINITIONS

         All terms defined in the Original Indenture referred to in the
Recitals hereto or in any of the supplements thereto referred to in such
Recitals are, unless the context otherwise requires, used herein with the same
meanings therein set forth.

                                  ARTICLE TWO
                          DEBENTURES DUE NOVEMBER 2025

         SECTION 2.01.  There shall be a series of Debentures designated as
"7.62% Debentures, Series Due November 2025" the aggregate principal amount of
which that may be outstanding being limited to $281,530,000.00, except as
provided in Section 2.10 of the Original Indenture.

         The Debentures Due November 2025 shall be substantially in the form 
recited in Exhibit A.

         SECTION 2.02.  The Debentures Due November 2025 shall be dated as
provided in Section 2.05 of this Article One; shall mature November 28, 2025;
shall bear interest at the rate of 7.62% per annum until paid or redeemed as
herein and in the Original Indenture provided, payable semiannually on each May
28 and November 28 to the holders of Debentures ("Debentureholders") in whose
names such Debentures Due November 2025 are registered at the close of business
on or, as the case may be, next preceding such May 13 or November 13 or, if
such date shall not be a Business Day, then the next preceding Business Day
(unless such Debenture has been called for redemption on a date fixed for such
redemption which is prior to such interest payment date), except that if the
Company shall default in the payment of any installment of interest on any
Debentures Due November 2025, such interest in default shall be paid to the
Debentureholders in whose names the Debentures Due November 2025 are registered
at the close of business on a record date established for the payment of such
defaulted interest, and interest thereon, by the Company in any lawful manner
not inconsistent with the requirements of any securities exchange on which the
Debentures Due November 2025 may be listed (such record date to be not less
than five days prior to the date for the payment of such defaulted interest);
and shall be payable as to both principal and interest in such coin or currency
of the United States of America as at the time of payment is legal tender for
the payment of public and private debts, at the corporate trust office of the
Trustee in the Borough of Manhattan, the City of New York.  Any such defaulted
installment of interest on any Debentures Due





                                       2
<PAGE>   6
November 2025 that is not paid when due shall bear interest, to the extent
lawful, at the rate per annum borne by such Debentures plus 1% per annum.

         SECTION 2.03.  The Debentures Due November 2025 shall be issued in
registered form without coupons in the denominations of $1,000 and any integral
multiple of $1,000.  Temporary Debentures Due November 2025 may be issued in
denominations as provided in Section 2.04 of the Original Indenture and shall
be exchangeable as provided in such temporary Debentures.

         SECTION 2.04.  The Debentures Due November 2025 may be redeemed prior
to maturity, at the election of the Company, as a whole at any time or in part
from time to time, in each case on or after November 28, 2005, at the
applicable redemption price or prices (expressed in percentages of principal
amount) set forth in the tabulation under the heading "Regular Redemption
Prices" in the form of Debentures Due November 2025 contained in Exhibit A to
this Supplemental Indenture, with accrued interest to the date fixed for
redemption.

         SECTION 2.05.  Each of the Debentures Due November 2025 shall be dated
the date of authentication, and shall bear interest from the interest payment
date to which interest has been paid last preceding the date thereof (unless
the date thereof is an interest payment date to which interest has been paid,
in which case from the date thereof, or unless the date thereof is prior to May
28, 1996 in which case from November 28, 1995).  Notwithstanding the foregoing,
if the date of the Debentures Due November 2025 is after May 13 or November 13,
as the case may be, and before the following May 28 or November 28, as the case
may be, such Debentures Due November 2025 shall bear interest from such May 28
or November 28; provided, however, that if and to the extent that the Company
shall default in the payment of interest due on such May 28 or November 28,
such Debentures Due November 2025 shall bear interest from the next preceding
May 28 or November 28 to which interest has been paid or, if no interest has
been paid, from November 28, 1995.

         SECTION 2.06.  The Debentures Due November 2025 will be issued in
fully registered form and will be represented by a global certificate or
certificates (the "Global Security") registered in the name of a nominee of The
Depository Trust Company (the "Depositary").  The Global Security representing
the Debentures Due November 2025 will be deposited with, or on behalf of, the
Depositary.  The Debentures Due November 2025 will not be exchangeable for
certificates issued in definitive, registered form at the option of the holder
and, except as set forth below, will not otherwise be issuable in definitive
form.

         So long as the Depositary for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depositary or its nominee, as
the case may be, will be considered the sole owner or holder of the Debentures
Due November 2025 for all purposes under the Original Indenture and this
Supplemental Indenture.  Except as provided below, beneficial owners of the
Debentures Due November 2025 will not be entitled to have the Debentures Due
November 2025 registered in their names, will not receive or be entitled to
receive physical delivery of Debentures Due November 2025 in definitive form
and will not be considered the owners or holders thereof under the Original
Indenture and this Supplemental Indenture.  Unless and until it is exchanged in
whole or in part for individual certificates evidencing the Debentures Due
November 2025 represented thereby, the Global Security may not be transferred
except as a whole by the Depositary for the Global Security to a nominee of
such Depositary or by a





                                       3
<PAGE>   7
nominee of such Depositary to such Depositary or another nominee of such
Depositary or by the Depositary or any nominee to a successor Depositary or any
nominee of such successor.

         If the Depositary with respect to the Global Security is at any time
unwilling or unable to continue as Depositary or if at any time the Depositary
shall no longer be eligible under Section 2.01 of the Original Indenture and a
successor Depositary is not appointed by the Company within 90 days, the
Company will issue definitive certificates in exchange for the Debentures Due
November 2025 represented by such Global Security.  In addition, the Company
may at any time and in its sole discretion determine not to use the
Depositary's book-entry system, and, in such event, will issue definitive
certificates in exchange for the Debentures Due November 2025 represented by
such Global Security.

         SECTION 2.07.  Until the earlier of (i) the date on which none of
Columbia Gas Transmission Corporation, any successor thereto and any transferee
of the assets of Columbia Gas Transmission Corporation as an entirety (or
substantially as an entirety) (collectively "TCO"), is a Significant Subsidiary
of the Company, and (ii) the fourth anniversary of the date on which any of the
New Indenture Securities (as described below) are first issued (said earlier
date being the "Covenant Expiration Date"), the Company shall, subject to
applicable law and regulation, hold not less than $600 million principal amount
of First Mortgage Bonds of TCO (the "First Mortgage Bonds") issued pursuant to
and entitled to the benefits of the TCO Indenture of Mortgage and Deed of Trust
(the "TCO Mortgage").  Until the Covenant Expiration Date, the lien in favor of
the Company under the TCO Mortgage securing the First Mortgage Bonds shall at
all times (i) cover all property and assets of TCO intended to be subject to
the TCO Mortgage as in effect on the date of this Supplemental Indenture, and
(ii) be a first priority perfected lien subject only to those exceptions that
are contained in the TCO Mortgage as in effect on the date of this Supplemental
Indenture, and the Company shall not release, or consent to any release of, any
property or assets from that lien, other than (x) as provided in the TCO
Mortgage as in effect on the date of this Supplemental Indenture and (y)
releases of property and assets in the normal course of TCO's business in
connection with the sale, other transfer or abandonment of such property or
assets.  Until the Covenant Expiration Date, no other Debt of any Person shall
be secured by any lien on any property or assets of TCO except as permitted
under the TCO Mortgage as in effect on the date of this Supplemental Indenture.

         Notwithstanding the foregoing, the Company shall not be in breach of
this Section 2.07(A) if the amount of the Company's holdings of First Mortgage
Bonds is less than $600 million principal amount for not more than an aggregate
of 30 days after the date of this Supplemental Indenture and prior to the
Covenant Expiration Date (the first day, subsequent to such 30th day, on which
the amount of such holdings is below $600 million being hereafter referred to
as the "Trigger Date") or (B) if on or before the sixtieth day after the
Trigger Date, the Company retires (as described below) or has previously
retired Company Funded Debt in an amount equal to 150% of the amount by which
$600 million exceeds the principal amount of the Company's holdings of First
Mortgage Bonds on the Trigger Date, or (C) if subsequent to the Trigger Date,
the principal amount of the Company's holdings of First Mortgage Bonds falls
below the amount of such holdings as of the Trigger Date or below the lowest
previous amount of such holdings subsequent to the Trigger Date (any such date,
a "Further Trigger Date") and the Company retires (as described below) or has
previously retired Company Funded Debt in an amount equal to 150% of the amount
by which $600 million exceeds the principal amount of





                                       4
<PAGE>   8
such holding on the Further Trigger Date, the amount of such retirement with
respect to any Further Trigger Date to be measured for purposes of determining
compliance with this provision as of the sixtieth day after such Further
Trigger Date.  The Company may "retire" Company Funded Debt by any one or more
of the following methods: (1) by cancellation of Company Funded Debt which it
acquires or reacquires, (2) by defeasance of Company Funded Debt in accordance
with the terms of such Company Funded Debt, (3) by a bona fide tender offer for
Company Funded Debt which, to the extent such tender offer is for New Indenture
Securities, is for principal amounts of each series of New Indenture Securities
that are proportionate to the relative principal amount of such series
outstanding on the relevant Trigger Date or Further Trigger Date (a tender
offer for any of the New Indenture Securities at par will be deemed to retire
an equivalent amount of Company Funded Debt, irrespective of the amount of New
Indenture Securities or the amount of any series thereof actually tendered), or
(4) by repayment or prepayment of Company Funded Debt in accordance with its
terms; provided, however, that repayment or prepayment of Company Funded Debt
under a banking loan facility shall not constitute retirement of such Debt
unless the Company shall have waived or terminated any entitlement it may have
thereunder to reborrow the amounts so repaid or prepaid.  In connection with
any such "retirement" of Company Funded Debt, the Company (i) shall "retire"
New Indenture Securities (treating the New Indenture Securities as a single
class) and other Company Funded Debt (treating all such other Company Funded
Debt as a single class) pro rata based on their respective outstanding
principal amounts on the relevant Trigger Date or Further Trigger Date or (ii)
may, at its option, "retire" a greater principal amount of New Indenture
Securities than is determined in accordance with the foregoing clause (i).  The
foregoing covenant shall not represent a limit on the amount of Company Funded
Debt or Funded Debt of TCO that may be outstanding from time to time.

         "Company Funded Debt" means all Debt (other than debt under a bank
loan commonly referred to as a "revolving credit facility") created, assumed or
guaranteed by the Company which matures by its terms, or is renewable at the
option of the Company to a date, more than one year after the date of the
original creation, assumption or guarantee of such Debt by the Company.

         "New Indenture Securities" means (i) the Debentures Due November 2025,
and (ii) the Company's 6.39% Debentures, Series Due November 2000, 6.61%
Debentures, Series Due November 2002, 6.80% Debentures, Series Due November
2005, 7.05% Debentures, Series Due November 2007, 7.32% Debentures, Series Due
November 2010 and 7.42% Debentures, Series Due November 2015, each issued under
the Original Indenture.

         "TCO Indenture of Mortgage and Deed of Trust" means the Indenture of
Mortgage and Deed of Trust, dated August 30, 1985, between Columbia Gas
Transmission Corporation and Wilmington Trust, as amended or restated from time
to time.





                                       5
<PAGE>   9
                                 ARTICLE THREE
                            MISCELLANEOUS PROVISIONS

         SECTION 3.01.  This Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

         SECTION 3.02.  This Supplemental Indenture and each of the Debentures
Due November 2025 shall be deemed to be a contract made under the laws of the
State of New York and for all purposes shall be construed in accordance with
and governed by the laws of said State.

         SECTION 3.03.  The recitals contained herein shall be taken as the
statements of the Company, and the Trustee assumes no responsibility for their
correctness.  The Trustee makes no representation as to the validity or
sufficiency of this Supplemental Indenture.





                                       6
<PAGE>   10
         IN WITNESS WHEREOF, The Columbia Gas System, Inc. has caused this
Supplemental Indenture to be executed in its corporate name by its Chairman of
the Board or its President or one of its Vice Presidents or its Treasurer, and
its corporate seal to be hereunto affixed and to be attested by its Secretary
or one of its Assistant Secretaries, and Marine Midland Bank has caused this
Supplemental Indenture to be executed in its corporate name and its corporate
seal to be hereunto affixed by one of its Vice Presidents and to be attested by
one of its Assistant Vice Presidents, all as of November 28, 1995.


                                        THE COLUMBIA GAS SYSTEM, INC.


Attest:    //s// C. M. Afshar           by:    //s// L. J. Bainter             
       -----------------------------       ------------------------------------
                  Secretary                           Treasurer
                                            
                                            
                                            
                                            
[CORPORATE SEAL]                            
                                            
                                            
                                            
                                            
                                            
                                        MARINE MIDLAND BANK, as Trustee
                                            
                                            
Attest:   //s// Robert A. Conrad        by:   //s// Metin Caner                
       -----------------------------       ------------------------------------
          Assistant Vice President            Metin Caner, Vice President





[CORPORATE SEAL]





                                       7
<PAGE>   11
STATE OF DELAWARE   )
                    ) ss:
New Castle County   )


         On this 28th day of November, 1995, before me personally came L. J.
Bainter, to me known, who, being by me duly sworn, did depose and say that he
resides at 20 Montchanin Road, Wilmington, Delaware 19807; that he is Treasurer
of THE COLUMBIA GAS SYSTEM, INC., one of the corporations described in and
which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument bearing the corporate
name of said corporation is such corporate seal; that it was so affixed by
order of the Board of Directors of said corporation; and that he signed his
name thereto by like order.



                                               //s// Majorie A. Murray         
                                            -----------------------------------
                                            Notary Public
                                            
                                            
                                                12/5/96                        
                                            -----------------------------------
                                            My commission expires





                                       8
<PAGE>   12
STATE OF NEW YORK  )
                   ) ss:
County of New York )



         On the 28th day of November, 1995, before me personally came Metin
Caner, to me known, who, being by me duly sworn, did depose and say that he
resides at 2350 Broadway, New York, NY 10024, and that he is a Vice President
of Marine Midland Bank, one of the corporations described in and which executed
the foregoing instrument; that he knows the seal of said corporation; that the
seal affixed to said instrument bearing the corporate name of said corporation
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.



                                                 //s// S. C. Derenchuk         
                                            -----------------------------------
                                            Notary Public
                                            
                                            
                                               6/12/97                         
                                            -----------------------------------
                                            My commission expires





                                       9
<PAGE>   13
                                                                       EXHIBIT A
                                                       TO SUPPLEMENTAL INDENTURE

                               FORM OF DEBENTURE
                                     (FACE)

         Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) to the
issuer or its agent for registration of transfer, exchange or payment, and any
certificate issued is registered in the name of Cede & Co. or such other name
as requested by an authorized representative of The Depository Trust Company
and any payment is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the registered
owner hereof, Cede & Co., has an interest herein.

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.62% DEBENTURE, SERIES DUE NOVEMBER 2025
                             DUE NOVEMBER 28, 2025

                                                             CUSIP NO. 197648CE6

No.______________                                                $______________

         THE COLUMBIA GAS SYSTEM, INC., a Delaware corporation (hereinafter
called the Company), for value received, hereby promises to pay to ________ or
registered assigns, the sum of $______________ on the twenty-eighth day of
November 2025 at the corporate trust office of Marine Midland Bank, Trustee
under the Indenture referred to on the reverse hereof, or its successor as such
Trustee, in the Borough of Manhattan, the City of New York, in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts, and to pay interest
thereon at the rate of 7.62% per annum in like coin or currency, payable at
said office semiannually on the twenty-eighth day of May and the twenty-eighth
day of November in each year, from the interest payment date to which interest
has been paid last preceding the date hereof (unless the date hereof is an
interest payment date to which interest has been paid, in which case from the
date hereof, or unless the date hereof is prior to May 28, 1996, in which case
from November 28, 1995) until the Company's obligation with respect to the
payment of such principal shall have been discharged, such interest to be paid
to the person who shall have been the registered owner hereof at the close of
business on May 13 or November 13, as the case may be, next preceding an
interest payment date, except as otherwise provided in the Indenture referred
to on the reverse hereof.  Notwithstanding, if the date of this Debenture is
after May 13 or November 13, as the case may be, and before the immediately
following May 28 or November 28, as the case may be, this Debenture shall bear
interest from such May 28 or November 28; provided, however, that if and to the
extent that the Company shall default in the payment of interest due on such
May 28 or November 28, this Debenture shall bear interest from the next
preceding May 28 or November 28 to which interest has been paid or, if no
interest has been paid, from November 28, 1995.  Any installment of interest on
this Debenture that is not paid when due shall bear interest at the rate borne
by this Debenture plus 1% per annum.





                                       10
<PAGE>   14
         Additional provisions of this Debenture are contained on the reverse
hereof and such provisions shall for all purposes have the same effect as
though fully set forth at this place.

         This Debenture shall not be valid or become obligatory for any purpose
until it shall have been authenticated by the certificate, hereon endorsed, of
the Trustee under the Indenture.

         IN WITNESS WHEREOF, The Columbia Gas System, Inc., has caused this
Debenture to be executed in its name by the facsimile signature of its Chairman
of the Board or its President or one of its Vice Presidents or its Treasurer,
and its corporate seal to be hereunto affixed, or a facsimile thereof to be
printed or engraved hereon, and to be attested by the facsimile signature of
its Secretary or one of its Assistant Secretaries.

                                        THE COLUMBIA GAS SYSTEM, INC.
                                        
Dated:   November 28, 1995              By: 
                                             --------------------------------
                                                        Treasurer
Attest:                                 



                 (FORM OF TRUSTEE'S CERTIFICATE ON DEBENTURES)

         This is one of the Debentures, of the series designated therein,
described in the within-mentioned Indenture.

                                        MARINE MIDLAND BANK, as Trustee

                                        By:
                                             --------------------------------
                                                   Authorized Signatory





                                       11
<PAGE>   15
                                   (REVERSE)

                         THE COLUMBIA GAS SYSTEM, INC.

                   7.62% DEBENTURE, SERIES DUE NOVEMBER 2025
                             DUE NOVEMBER 28, 2025

         This Debenture is one of a duly authorized issue of Debentures of the
Company issuable in series, and is one of a series known as its 7.62%
Debentures, Series Due November 2025 (herein called Debentures Due November
2025), all issued and to be issued under an Indenture dated as of November 28,
1995, as supplemented by seven indentures supplemental thereto, including a
Seventh Supplemental Indenture dated as of November 28, 1995, in which the
Debentures Due November 2025 are created and described, all executed between
the Company and Marine Midland Bank (herein called the Trustee), Trustee, to
which the  Indenture and all indentures supplemental thereto (herein
collectively called the Indenture) reference is hereby made for a statement of
the rights thereunder of the Trustee and of the holders of the Debentures, and
of the duties thereunder of the Trustee and of the Company.

         The rights and obligations of the Company and of the holders of
Debentures may be changed and modified at the request of the Company by an
indenture or indentures supplemental to the Indenture, executed pursuant to the
consent in writing of the holders of at least a majority in principal amount of
the Debentures then outstanding affected by such change or modification, all in
the manner and subject to the limitations set forth in the Indenture, provided
that no such change or modification by such supplemental indenture shall extend
the maturity of, or reduce the rate of interest on, or otherwise modify the
terms of payment of the principal of, or the premium, if any, or the interest
on, this Debenture, or reduce the percentage of Debentures the holders of which
are required to consent to any such supplemental indenture, or modify the
provision as to the holders of any series of Debentures authorized or required
to consent to any such supplemental indenture, without the express consent of
the holder hereof.  Any such consent by the holder of this Debenture (unless
effectively revoked as provided in the Indenture) shall be conclusive and
binding upon such holder and upon all future holders and owners of this
Debenture, whether or not any notation of such consent is made upon this
Debenture.

         The Debentures Due November 2025 may be redeemed, prior to maturity,
at the election of the Company, as a whole at any time, or in part from time to
time, in each case on or after November 28, 2005, as provided in the Indenture,
at the redemption prices (expressed in percentages of principal amount) set
forth in the tabulation below under the heading "Regular Redemption Prices":





                                       12
<PAGE>   16
<TABLE>
<CAPTION>
                                     If Redeemed During 12                                       Regular
                                         Months' Period                                         Redemption
                                           Commencing                                             Prices
                                           ----------                                             ------
                                   <S>                                                           <C>
                                   November 28, 2005                                             103.61%

                                   November 28, 2006                                             103.21%

                                   November 28, 2007                                             102.81%

                                   November 28, 2008                                             102.41%

                                   November 28, 2009                                             102.01%

                                   November 28, 2010                                             101.60%

                                   November 28, 2011                                             101.20%

                                   November 28, 2012                                             100.80%

                                   November 28, 2013                                             100.40%

                                   November 28, 2014                                             100.00%

                                   November 28, 2015                                             100.00%

                                   November 28, 2016                                             100.00%

                                   November 28, 2017                                             100.00%

                                   November 28, 2018                                             100.00%

                                   November 28, 2019                                             100.00%

                                   November 28, 2020                                             100.00%

                                   November 28, 2021                                             100.00%

                                   November 28, 2022                                             100.00%

                                   November 28, 2023                                             100.00%

                                   November 28, 2024                                             100.00%
</TABLE>


         In case a default, as defined in the Indenture, shall occur, the
principal of all the Debentures then outstanding may become or be declared due
and payable in the manner and with the effect provided in the Indenture.  The
Indenture provides that in certain events such declaration and certain defaults
under the Indenture may be waived by the holders of a majority in principal
amount of all Debentures outstanding.

         This Debenture is transferable and exchangeable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized
attorney, at the corporate trust office of the Trustee in said Borough of
Manhattan, upon surrender and cancellation of this Debenture,





                                       13
<PAGE>   17
and, thereupon, a new fully registered Debenture or Debentures Due November
2025 of the same aggregate principal amount shall be issued in exchange
therefor as provided in the Indenture.  The Company and the Trustee may deem
and treat the person in whose name this Debenture is registered as the absolute
owner hereof for the purpose of receiving payment of or on account of the
principal, premium, if any, and interest (except as stated in the first
paragraph on the face hereof) due hereon and for all other purposes.

         No recourse shall be had for the payment of the principal of, or the
premium, if any, or the interest on, this Debenture, or any part hereof, or for
any claim based hereon or otherwise in respect hereof, or of the indebtedness
represented hereby, or upon any obligation, covenant or agreement of the
Indenture, against any incorporator, stockholder, officer or director, as such,
past, present or future, of the Company or of any successor corporation (either
directly or through the Company or any such successor corporation), whether by
virtue of any constitutional provision, statute or rule of law, or by the
enforcement of any assessment or penalty or otherwise, all liability, if any,
of that character against every such incorporator, stockholder, officer and
director being by the acceptance hereof, and as part of the consideration for
the issue hereof, expressly waived and released.

         This Debenture shall be deemed to be a contract made under the laws of
the State of New York and for all purposes shall be construed in accordance
with and governed by the laws of said State.





                                       14

<PAGE>   1
                                                                       EXHIBIT 5





                            CRAVATH, SWAINE & MOORE
                                Worldwide Plaza
                               825 Eighth Avenue
                              New York, N.Y. 10019


                         The Columbia Gas System, Inc.


Ladies & Gentlemen:

                 We have acted as counsel for The Columbia Gas System, Inc., a
Delaware corporation (the "Company"), in connection with the proposed issuance
and sale from time to time pursuant to Rule 415 under the Securities Act of
1993 (the "Securities Act") of up to an aggregate of $1,000,000,000 of (i)
Debentures of the Company to be issued under an Indenture dated as of November
28, 1995, (the "Indenture"), between the Company and Marine Midland Bank (the
"Trustee"), (ii) preferred stock (the "Preferred Stock") of the Company and/or
(iii) common stock (the "Common Stock") of the Company (the Debentures,
Preferred Stock and Common Stock are collectively referred to herein as the
"Securities").

                 In that connection, we have examined originals, or copies
certified or otherwise identified to our satisfaction, of such documents,
corporate records and other instruments as we have deemed necessary for the
purposes of this opinion, including the following:  (a) the Certificate of
Incorporation of the Company, as amended; (b) the By- laws of the Company; (c)
the Indenture; and (d) the form of the Deposit Agreement (the "Deposit
Agreement") filed as Exhibits to the Registration Statement.

                 Based upon and subject to the foregoing and assuming that (i)
the Registration Statement and any amendments thereto (including post-effective
amendments) will have become effective and comply with all applicable laws;
(ii) the Registration Statement will be effective and will comply with all
applicable laws at the time the Securities are offered or issued as
contemplated by the Registration Statement; (iii) a Prospectus Supplement or
term sheet will have been prepared and filed with the Securities and Exchange
Commission describing the Securities offered thereby and will
<PAGE>   2
                                                                               2



comply with all applicable laws; (iv) all Securities will be issued and sold in
compliance with applicable federal and state securities laws and in the manner
stated in the Registration Statement and the appropriate Prospectus Supplement;
(v) a definitive purchase, underwriting or similar agreement with respect to
any Securities offered or issued will have been duly authorized and validly
executed and delivered by the Company and the other parties thereto; and (vi)
any Securities issuable upon conversion, exchange or exercise of any Security
being offered or issued will be duly authorized, created and, if appropriate,
reserved for issuance upon such conversion, exchange or exercise, we are of
opinion as follows:

                 (1) the Company is a validly existing corporation under the
         laws of the State of Delaware;

                 (2) with respect to Debentures to be issued under the
         Indenture, when (A) the Trustee is qualified to act as Trustee, under
         the Indenture, (B) the Trustee has duly executed and delivered the
         Indenture, (C) the Indenture has been duly authorized and validly
         executed and delivered by the Company to the Trustee, (D) the
         Indenture has been duly qualified under the Trust Indenture Act of
         1939, as amended, (E) the Board of Directors of the Company or a duly
         constituted and acting committee thereof (such Board of Directors or
         committee being hereinafter referred to as the "Board") has taken all
         necessary corporate action to approve the issuance and terms of such
         Debentures, the terms of the offering thereof and related matters, and
         (F) such Debentures have been duly executed, authenticated, issued and
         delivered in accordance with the provisions of the Indenture and the
         applicable definitive purchase, underwriting or similar agreement
         approved by the Board upon payment of the consideration therefor
         provided for therein, such Debentures will be validly issued and will
         constitute valid and binding obligations of the Company, enforceable
         against the Company in accordance with their terms, (subject to
         applicable bankruptcy, insolvency, reorganization,  fraudulent
         conveyance, moratorium or other similar laws affecting creditors'
         rights generally from time to time  in effect and subject to general
         principles of equity, regardless of whether such enforceability is
         considered in a proceeding in equity or at law);

                 (3) with respect to shares of Preferred Stock, when both (A)
         the Board has taken all necessary corporate action to approve the
         issuance and terms of the shares of Preferred Stock, the terms of the
         offering thereof, and related matters, including the adoption of a
         Certificate of Amendment relating to such Preferred Stock (a
         "Certificate") and the filing of the Certificate with the Secretary of
         State of the State of Delaware, and (B) certificates representing the
         shares of Preferred Stock have been duly executed, countersigned,
         registered and delivered either (i) in accordance with the applicable
         definitive purchase, underwriting or similar
<PAGE>   3
                                                                               3


         agreement approved by the Board upon payment of the consideration
         therefor (not less than the par value of the Preferred Stock) provided
         for therein or (ii) upon conversion or exercise of any other Security,
         in accordance with the terms of such Security or the instrument
         governing such Security providing for such conversion or exercise as
         approved by the Board, for the consideration approved by the Board
         (not less than the par value of the Preferred Stock), then the shares
         of Preferred Stock will be validly issued, fully paid and
         nonassessable;

                 (4) with respect to shares of Common Stock when both (A) the
         Board has taken all necessary corporate action to approve the issuance
         of and the terms of the offering of the shares of Common Stock and
         related matters and (B) certificates representing the shares of Common
         Stock have been duly executed, countersigned, registered and delivered
         either (i) in accordance with the applicable definitive purchase,
         underwriting or similar agreement approved by the Board upon payment
         of the consideration therefor (not less than the par value of the
         Common Stock) provided for therein or (ii) upon conversion or exercise
         of any other Security, in accordance with the terms of such Security
         or the instrument governing such Security providing for such
         conversion or exercise as approved by the Board, for the consideration
         approved by the Board (not less than the par value of the Common
         Stock), then the shares of Common Stock will be validly issued, fully
         paid and nonassessable; and

                 We know that we may be referred to, as counsel who has passed
upon the validity of the Debentures or the issuance of the Preferred Stock and
Common Stock by the Company, in a supplement to the Prospectus forming a part
of the Registration Statement on Form S-3 relating to the Securities filed with
the U.S. Securities and Exchange Commission pursuant to the Securities Act, and
we hereby consent to such use of our name in said Registration Statement and to
the use of this opinion for filing with said Registration Statement as Exhibit
(5) thereto.



                                                     Very truly yours,


                                                     CRAVATH, SWAINE & MOORE


The Columbia Gas System, Inc.
   20 Montchanin Road
          Wilmington, Delaware 19807


<PAGE>   1



                                                                      EXHIBIT 12

                 THE COLUMBIA GAS SYSTEM, INC. AND SUBSIDIARIES

           Statements of Adjusted Ratio of Earnings to Fixed Charges
                                ($ in millions)



<TABLE>
<CAPTION>
                                                                           Twelve Months           
                                                                        Ended September 30,       
                                                                    ----------------------------   
                                                                                              
                                                                       1995              1994     
                                                                       ----              ----     
<S>                                                                   <C>               <C>   
Consolidated Income (Loss) from Continuing Operations                                         
 before Income Taxes and Cumulative Effect of Accounting                                      
 Change . . . . . . . . . . . . . . . . . . . . . . . . . . .         400.5             410.5 
                                                                                              
Adjustments:                                                                                  
  Interest during construction  . . . . . . . . . . . . . . .          (5.4)             (3.0)
  Distributed (Undistributed) equity income . . . . . . . . .          (9.4)             (1.4)
  Fixed charges, excluding interest not recorded  . . . . . .          22.5              20.5 
                                                                    ---------        ---------
    Earnings Available  . . . . . . . . . . . . . . . . . . .         408.2             426.6 
                                                                    ---------        ---------
                                                                                              
Fixed Charges:                                                                                
  Interest on long-term and short-term debt . . . . . . . . .           0.4               0.7 
  Interest not recorded *,**. . . . . . . . . . . . . . . . .         269.8             230.5 
  Other interest  . . . . . . . . . . . . . . . . . . . . . .          22.1              19.8 
                                                                   ----------        ---------
    Total Fixed Charges before Adjustments. . . . . . . . . .         292.3             251.0 
                                                                   ----------        ---------
                                                                                              
Adjustments:                                                                                  
  Gain/(Loss) on reacquired debt  . . . . . . . . . . . . . .             -                 - 
                                                                   ----------       ----------
    Total Fixed Charges . . . . . . . . . . . . . . . . . . .         292.3             251.0 
                                                                   ----------       ----------
                                                                                              
Ratio of Earnings Before Taxes to Fixed Charges . . . . . . .          1.40              1.70 
                                                                     ========         ========
</TABLE>

<TABLE>
<CAPTION>
                                                                                               Twelve Months
                                                                                            Ended December  31,               
                                                                 -------------------------------------------------------------------
                                                                                                                                  
                                                                          1994             1993             1992             1991 
                                                                          ----             ----             ----             ----
<S>                                                                      <C>              <C>              <C>           <C>      
Consolidated Income (Loss) from Continuing Operations                                                                             
 before Income Taxes and Cumulative Effect of Accounting                                                                          
 Change . . . . . . . . . . . . . . . . . . . . . . . . . . .            392.2            288.1            161.4         (1,205.8)
                                                                                                                                  
Adjustments:                                                                                                                      
  Interest during construction  . . . . . . . . . . . . . . .             (4.1)            (3.1)            (4.0)            (3.4)
  Distributed (Undistributed) equity income . . . . . . . . .             (0.9)            (0.1)            (0.1)            (2.4)
  Fixed charges, excluding interest not recorded  . . . . . .             14.8            101.5             13.7            139.9 
                                                                      ---------         --------        ---------        ---------
    Earnings Available  . . . . . . . . . . . . . . . . . . .            402.0            386.4            171.0         (1,071.7)
                                                                      ---------         --------        ---------        ---------
                                                                                                                                  
Fixed Charges:                                                                                                                    
  Interest on long-term and short-term debt . . . . . . . . .              0.7              3.1              4.9            112.4 
  Interest not recorded *,**. . . . . . . . . . . . . . . . .            238.2            218.7            213.1            101.5 
  Other interest  . . . . . . . . . . . . . . . . . . . . . .             14.1             98.4              8.8             27.6 
                                                                     ----------         --------        ---------        ---------
    Total Fixed Charges before Adjustments. . . . . . . . . .            253.0            320.2            226.8            241.5 
                                                                     ----------         --------        ---------        ---------
                                                                                                                                  
Adjustments:                                                                                                                      
  Gain/(Loss) on reacquired debt  . . . . . . . . . . . . . .                -                -                -             (0.1)
                                                                      ---------         --------        ---------        ---------
    Total Fixed Charges . . . . . . . . . . . . . . . . . . .            253.0            320.2            226.8            241.4 
                                                                      ---------         --------        ---------        ---------
                                                                                                                                  
Ratio of Earnings Before Taxes to Fixed Charges . . . . . . .             1.59             1.21            N/A(a)           N/A(a) 
                                                                      =========         ========          =======        =========
</TABLE>

<TABLE>
<CAPTION>
                                                                       Twelve Months
                                                                     Ended December  31,              
                                                                     -------------------
                                                              
                                                                           1990
                                                                           ----
<S>                                                                       <C>
Consolidated Income (Loss) from Continuing Operations          
 before Income Taxes and Cumulative Effect of Accounting       
 Change . . . . . . . . . . . . . . . . . . . . . . . . . . .             162.6
                                                               
Adjustments:                                                   
  Interest during construction  . . . . . . . . . . . . . . .             (10.0)
  Distributed (Undistributed) equity income . . . . . . . . .               2.9
  Fixed charges, excluding interest not recorded  . . . . . .             182.5 
                                                                       ---------
    Earnings Available  . . . . . . . . . . . . . . . . . . .             338.0 
                                                                       ---------
                                                               
Fixed Charges:                                                 
  Interest on long-term and short-term debt . . . . . . . . .             170.6
  Interest not recorded *,**. . . . . . . . . . . . . . . . .                 -
  Other interest  . . . . . . . . . . . . . . . . . . . . . .              10.5 
                                                                       ---------
    Total Fixed Charges before Adjustments. . . . . . . . . .             181.1 
                                                                       ---------
                                                               
Adjustments:                                                   
  Gain/(Loss) on reacquired debt  . . . . . . . . . . . . . .               1.4 
                                                                       ---------
    Total Fixed Charges . . . . . . . . . . . . . . . . . . .             182.5 
                                                                       ---------
                                                               
Ratio of Earnings Before Taxes to Fixed Charges . . . . . . .              1.85 
                                                                       =========
</TABLE>



(a) To achieve a one-to-one coverage, the Corporation would need an additional
$55.8 and $1,313.1 million of earnings in 1992 and 1991 respectively.

 *  This amount includes approximately $261.2 million interest expense not
    recorded in the twelve months ended September 30, 1995, $221.9 million
    interest expense not recorded in the twelve months ended September 30,
    1994, $229.6 million, $210.1 million, $204.5 million and $86.0 million of
    interest expense not recorded for the twelve months ended 1994, 1993, 1992
    and 1991, respectively.  Reference is made to the Statements of
    Consolidated Income for the quarterly period ended September 30, 1995, as
    reported on Form 10-Q and to Note 2 of Notes to Consolidated Financial
    Statements of the Corporation's Annual Report on Form 10-K for the year
    ended December 31, 1994.


**  This amount includes $8.6 million of interest expense not recorded with
    respect to the registrant's guarantee of LESOP Trust's debentures for each
    of the twelve months ended September 30, 1995 and September 30, 1994,
    respectively.  Also included are $8.6 million, $8.6 million, $8.6 million,
    and $15.5 million of interest expense not recorded with respect to the
    registrant's guarantee of LESOP Trust's debentures for the twelve months
    ended December 31, 1994, 1993, 1992, and 1991, respectively.

<PAGE>   1

                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS




As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement of our report dated February 9, 1995
included in The Columbia Gas System's Form 10-K for the year ended December 31,
1994 and to all references to our Firm included in the registration statement.



/s/ Arthur Andersen LLP                        
- -----------------------------------------------
ARTHUR ANDERSEN LLP
February 15, 1996

<PAGE>   1
                                                                Exhibit 23-B-2


        [PRINTED ON RYDER SCOTT COMPANY PETROLEUM ENGINEERS LETTERHEAD]




                                    CONSENT


        As independent petroleum and natural consultants, we hereby consent to
the filing of this Letter Report dated February 3, 1995 in its entirety as an
Exhibit to the 1994 Annual Report of The Columbia Gas System, Inc., to the
Securities and Exchange Commission on Form 10-K, and any Registration Statement
of The Columbia Gas System, Inc. relating to the issue of securities to the
public during 1995 and the first quarter of 1996; to the quotation or
summarization of portions of this Letter Report, subject to our approval of the
related page(s) of the document(s), in the 10-K, the Prospectus included in
said Registration Statement(s) or the 1994 annual Report to Stockholders; and,
subject to approval of the related page(s) of the document(s), to the use of
our name and the reliance upon our authority as experts in said Annual Report
to Stockholders, Form 10-K and Prospectus(es) and in Part II of said
Registration Statement(s).  We have no interest of a substantial or material
nature in The Columbia Gas System, Inc., or in any affiliate, nor are we to
receive any such interest as payment for the preparation of this Letter Report;
we have not been employed for such preparation on a contingent fee basis; and
we are not connected with The Columbia Gas System, Inc., or any affiliate as a
promoter, underwriter, voting trustee, director, officer, employee, or
affiliate.

                                  RYDER SCOTT COMPANY
                                  PETROLEUM ENGINEERS
                                  
                                  
                                  /s/ Ryder Scott Company Petroleum Engineers
                                  -------------------------------------------

Houston, Texas
January 4, 1996


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