COLUMBIA ENERGY GROUP
10-K, 1999-03-26
NATURAL GAS TRANSMISISON & DISTRIBUTION
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<PAGE>   1
                                                      Commission File No. 1-1098

                 As filed with the United States Securities and
                     Exchange Commission on March 26, 1999.

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



                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10-K

     |X|          ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                   For the Fiscal Year Ended DECEMBER 31, 1998

                                       or

     | |        TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                  For the Transition Period from _____ to _____

                     C O L U M B I A  E N E R G Y  G R O U P
             ------------------------------------------------------
             (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.)

  13880 Dulles Corner Lane, Herndon, VA                   20171-4600       
- -----------------------------------------            --------------------
(Address of principal executive officers)                 (Zip Code)

        Registrant's telephone number, including area code (703) 561-6000
                                                           --------------

Securities registered pursuant to Section 12(b) of the Act:

                                                                 
<TABLE>
<CAPTION>
                                                               Name of Each Exchange
 Title of Each Class                                            on Which Registered              
 -------------------                                            -------------------              
<S>                                                           <C>  
Common Stock, $10 Par Value . . . . . . . . . . . . . . .     New York Stock Exchange
</TABLE>

Debentures
- ----------
6.39% Series A due November 28, 2000 
6.61% Series B due November 28, 2002 
6.80% Series C due November 28, 2005 
7.05% Series D due November 28, 2007 
7.32% Series E due November 28, 2010 
7.42% Series F due November 28, 2015 
7.62% Series G due November 28, 2025

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the proceeding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days: Yes  |X|  or No  | |

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.  |X|

The aggregate market value of the outstanding common shares of the Registrant
held by nonaffiliates as of February 28, 1999, was $4,189,550,000. For purposes
of the foregoing calculation, all directors and/or officers have been deemed to
be affiliates, but the registrant disclaims that any of such directors and/or
officers is an affiliate.

The number of shares outstanding of each class of common stock as of February
28, 1999, was: Common Stock $10 Par Value: 83,507,697 shares outstanding.

                       Documents Incorporated by Reference
                       -----------------------------------
Part III of this report incorporates by reference specific portions of the
Registrant's Proxy Statement relating to the 1999 Annual Meeting of
Stockholders.
<PAGE>   2
                                    CONTENTS



<TABLE>
<CAPTION>
                                                                                                             Page
Part I                                                                                                       No. 
- ------                                                                                                       --- 
<S>                                                                                                        <C>
         Item 1.  Business......................................................................              3

         Item 2.  Properties....................................................................              7

         Item 3.  Legal Proceedings.............................................................              9

         Item 4.  Submission of Matters to a Vote of Security Holders...........................             12

Part II

         Item 5.  Market for the Registrant's Common Equity and Related Stockholder Matters.....             12

         Item 6.  Selected Financial Data.......................................................             13

         Item 7.  Management's Discussion and Analysis of Financial Condition and
                  Results of Operations.........................................................             15

         Item 8.  Financial Statements and Supplementary Data...................................             40

         Item 9.  Change In and Disagreements with Accountants on Accounting and
                  Financial Disclosure..........................................................             71

Part III

         Item 10. Directors and Executive Officers of the Registrant............................             71

         Item 11. Executive Compensation........................................................             71

         Item 12. Security Ownership of Certain Beneficial Owners and Management................             71

         Item 13. Certain Relationships and Related Transactions................................             71

Part IV

         Item 14. Exhibits, Financial Statement Schedules and Reports on Form 8-K...............             72

         Undertaking made in Connection with 1933 Act Compliance on Form S-8....................             72

         Signatures.............................................................................             73

         Exhibits...............................................................................             74
</TABLE>

                                       2
<PAGE>   3
                                     PART 1

ITEM 1.  BUSINESS

General
Columbia Energy Group (Columbia), formerly The Columbia Gas System, Inc. and its
subsidiaries comprise one of the nation's largest integrated natural gas systems
engaged in natural gas transmission, natural gas distribution, and exploration
for and production of natural gas and oil. Columbia is also engaged in related
energy businesses including the marketing of natural gas and electricity, the
generation of electricity, primarily fueled by natural gas, and the distribution
of propane. Columbia, organized under the laws of the State of Delaware on
September 30, 1926, is a registered holding company under the Public Utility
Holding Company Act of 1935, as amended, (1935 Act) and derives substantially
all its revenues and earnings from the operating results of its 18 direct
subsidiaries. Columbia owns all of the securities of these direct subsidiaries
except for approximately 8 percent of the stock in Columbia LNG Corporation.
Columbia and its subsidiaries are sometimes collectively referred to herein as
the Columbia Group.

On January 20, 1998, Columbia announced that its name had been changed from The
Columbia Gas System, Inc. to Columbia Energy Group to better reflect its
expanded participation in the energy marketplace.

Columbia and its principal pipeline subsidiary, Columbia Gas Transmission
Corporation (Columbia Transmission), emerged from bankruptcy on November 28,
1995, after filing separate petitions for protection under Chapter 11 of the
Federal Bankruptcy Code (Bankruptcy Code) on July 31, 1991. During the
bankruptcy period, both Columbia and Columbia Transmission were
debtors-in-possession under the Bankruptcy Code and continued to operate their
businesses in the normal course subject to the jurisdiction of the United States
Bankruptcy Court for the District of Delaware.

Transmission and Storage Operations
Columbia's two interstate pipeline subsidiaries, Columbia Transmission
and Columbia Gulf Transmission Company (Columbia Gulf),  operate a 16,700-mile
pipeline network extending from offshore in the Gulf of Mexico to Lake Erie,
New York and the eastern seaboard. In addition, Columbia Transmission operates
one of the nation's largest underground natural gas storage systems. Together,
Columbia Transmission and Columbia Gulf serve customers in fifteen
northeastern, midatlantic, midwestern, and southern states and the District of
Columbia. Columbia Gulf's pipeline system extends from offshore Louisiana to
West Virginia and transports a major portion of the gas delivered by Columbia
Transmission. It also transports gas for third parties within the production
areas of the Gulf Coast. Columbia Pipeline Corporation and its wholly-owned
subsidiary, Columbia Deep Water Services Company, were formed to operate
pipeline and gathering facilities that are not regulated by the Federal Energy
Regulatory Commission (FERC).

Columbia Transmission and Columbia Gulf provide an array of competitively priced
natural gas transportation and storage services for local distribution companies
and industrial and commercial customers who contract directly with producers or
marketers for their gas supplies.

During 1998, Columbia Transmission continued construction of the
largest ever expansion of its storage and transportation system. In April 1998,
the second phase of storage service began and transportation service started in
November 1998. Upon completion, which is expected in 1999, the expansion will
add approximately 500,000 Mcf per day of firm service to 23 customers. Columbia
Transmission is also participating in the proposed 442-mile Millennium Pipeline
Project that has been submitted to the FERC for approval. As proposed, the
project will transport approximately 700,000 Mcf per day of natural gas from
the Lake Erie region to eastern markets. For additional information regarding
the transmission and storage operation's expansion projects see Item 7, page
22.

Distribution Operations
Columbia's five distribution subsidiaries provide natural gas service to nearly
2.1 million residential, commercial and industrial customers in Ohio,
Pennsylvania, Virginia, Kentucky and Maryland. Approximately 32,000 miles of
distribution pipelines serve these major markets. The distribution subsidiaries
have initiated transportation programs that allow residential and small
commercial customers the opportunity to choose their natural gas suppliers and
to use the distribution subsidiaries for transportation service. This ability to
choose a supplier was previously limited to larger commercial and industrial
customers. See "Competition" on page 27 for additional information.

                                       3
<PAGE>   4
ITEM 1.  BUSINESS (Continued)

Exploration and Production Operations
Columbia's exploration and production subsidiary, Columbia Energy Resources,
Inc. (Columbia Resources), explores for, develops, gathers and produces natural
gas and oil in Appalachia and Canada. As of December 31, 1998, Columbia
Resources held interests in approximately 2.7 million net acres of gas and oil
leases and had proved gas reserves of 802 billion cubic feet of natural gas
equivalent. In August 1997, Columbia Resources acquired Alamco, Inc. (Alamco),
an Appalachian gas and oil exploration and development company. During the first
quarter of 1998, Columbia Resources purchased 26 producing wells and
approximately 5,000 undeveloped acres in Ontario, Canada. Through its operations
in north-central West Virginia, southern Kentucky and northern Tennessee,
Columbia Resources is one of the largest-volume independent natural gas and oil
producers in the Appalachian Basin. For additional information, see Item 7, page
32.

Marketing Operations
Columbia Energy Services Corporation (Columbia Energy Services), and its
subsidiaries conduct Columbia's nonregulated natural gas and electric power
marketing operations and provide an array of energy supply and fuel management
services to distribution companies, independent power producers and other large
end-users both on and off Columbia's transmission and distribution pipeline
systems. Columbia Energy Services is also providing natural gas supplies to
retail customers as a result of the unbundling of services that is occurring at
the local distribution level. Columbia Energy Services, through its subsidiary,
Columbia Service Partners, Inc. (Columbia Service), provides a variety of
energy-related services to both homeowners and businesses. In 1997, Columbia
Energy Services acquired PennUnion Energy Services L.L.C. (PennUnion), an
energy-marketing affiliate of the Pennzoil Company. See Item 7, page 34, for
additional information.

Propane, Power Generation and LNG Operations
Columbia Propane Corporation (Columbia Propane) sells propane at wholesale and
retail to nearly 113,750 customers in parts of 10 states and the District of
Columbia. In 1998, Columbia Propane purchased the propane assets of three
companies that added approximately 12,500 new customers and 6.4 million gallons
of annual propane sales to Columbia Propane.

Columbia Electric Corporation's (Columbia Electric) primary focus has been the
development, ownership and operation of natural gas-fueled cogeneration power
plants that sell electric power to local electric utilities under long-term
contracts. Columbia Electric is part owner in three cogeneration projects. These
facilities produce both electricity and useful thermal energy fueled principally
by natural gas. Columbia Electric holds various interests in these facilities
that have a total capacity of approximately 250 megawatts.

In June 1998, Columbia Electric and LG&E Power Inc., a subsidiary of LG&E Energy
Corporation, announced an agreement for Columbia to participate in the
development of a gas-fired cogeneration project that would have a total
equivalent capacity of approximately 550 megawatts. The facility will provide
steam and electric services to a Reynolds Metals plant in Gregory, Texas, and
will also provide electricity to the Texas energy market. Construction began in
August 1998 and financing for the $257 million project was secured in November
of 1998.

In January 1998, Columbia Electric and Westcoast Energy Inc. signed a joint
ownership agreement to develop three gas-fired electric generation plants by
2001. In total, the three plants would provide approximately 1,000 megawatts of
electricity using approximately 160 MMcf per day of natural gas. In August 1998,
a site was purchased in Pennsylvania to build the first plant that will cost
about $300 million to develop and would produce 500 megawatts of electricity and
consume approximately 80 MMcf per day of natural gas. Each of the sponsors will
own a 50% interest in the project. The exact locations of the other two plants
have yet to be determined.

Columbia LNG Corporation is a partner with Potomac Electric Power Company in the
Cove Point LNG Limited Partnership (Partnership). The Partnership owns one of
the largest natural gas peaking and storage facilities in the United States
located in Cove Point, Maryland. The facility has the capacity to liquefy
natural gas at a rate of 15,000 Mcf of natural gas per day. The facility enables
liquefied natural gas to be stored until needed for the winter peak-day
requirements of utilities and other large gas users.

Columbia Network Services Corporation (Columbia Network), a wholly owned
subsidiary of Columbia, and its subsidiaries provide telecommunications and
information services and assist personal communications services and other
microwave radio service licensees in locating and constructing antenna
facilities.

Columbia Transmission Communications Corporation, another Columbia subsidiary,
is involved in the development of a dark fiber optics network for voice and data
communications.

                                       4
<PAGE>   5
ITEM 1. BUSINESS (Continued)
For additional discussion of the Columbia Group's business segments, including
financial information for the last three fiscal years, see Item 7, pages 22
through 38 and Note 16 on pages 64 through 65 of Item 8.

Competition and Business Strategies
Open access to natural gas supplies over interstate pipelines and the
deregulation of the commodity price of gas has led to tremendous change in the
energy markets, which continue to evolve. During this period, local distribution
(LDC) customers and marketers began to purchase gas directly from producers and
marketers and an open competitive market for gas supplies emerged. This
separation or "unbundling" of the transportation and other services offered by
pipelines and LDCs allows customers to select the service they want independent
from the purchase of the commodity. Columbia's distribution subsidiaries are
involved in programs that provide residential customers the opportunity to
purchase their natural gas requirements from third parties and use the
distribution subsidiaries for transportation services. It is likely that, over
time, distribution companies will have a very limited merchant function. At the
same time that the natural gas markets are evolving, the markets for competing
energy sources are also changing. Open access to interstate transmission of
electricity was approved by the FERC in 1997 and is providing for increased
competition in the market for electricity as well. For additional information
regarding competition, see Item 7.

In order to capitalize on the opportunities presented by this increasingly
competitive environment, Columbia's management has been implementing a more
responsive, entrepreneurial, customer-focused organization that will utilize
Columbia's core asset strengths, its expansive customer base and its knowledge
and experience in the energy markets and expects to establish Columbia as a
"total energy company," a leading provider of energy and energy-related
services.

An integral part of Columbia's financial strategy is the application of a value
added approach, called Columbia Value Added (CVA), to all of its businesses. CVA
is a financial process as well as a financial measure that determines whether
the anticipated return on a business activity or project exceeds its risk
adjusted capital cost. All discretionary capital expenditures are subject to the
CVA process. CVA is also being employed in Columbia's strategic planning process
and is one of the tools used to set management compensation levels.

One of management's objectives is to continue to improve the quality of its
credit rating and to better position Columbia to take advantage of business
opportunities as they arise. To further enhance its financial flexibility,
Columbia has a $900 million five-year revolving credit facility and a $450
million 364-day revolving credit facility with a one-year loan option. The
five-year facility provides for the issuance of up to $300 million of letters of
credit. In 1998, Moody's Investors Service, Inc. (Moody's) and Fitch Investors
Service (Fitch), upgraded Columbia's long-term debt rating to A3 and A,
respectively. Standard & Poor's Ratings Group (S&P) rates Columbia's long-term
debt at BBB+. Columbia's commercial paper ratings are F-1 by Fitch, P-2 by
Moody's and A-2 by S&P.

The foregoing discussion and Item 3 include statements regarding market risk
sensitive instruments and contains "forward-looking statements," within the
meaning of Section 27A of the Securities Act of 1933 and Section 21E of the
Securities Exchange Act of 1934. Investors and prospective investors should
understand that several factors govern whether any forward-looking statement
contained herein will be or can be achieved. Any one of those factors could
cause actual results to differ materially from those projected herein. These
forward-looking statements include, but are not limited to, statements
concerning Columbia's plans, objectives, expected performance, expenditures and
recovery of expenditures through rates, stated on either a consolidated or
segment basis, and including any and all underlying assumptions and other
statements that are other than statements of historical fact. From time to time,
Columbia may publish or otherwise make available forward-looking statements of
this nature. All such subsequent forward-looking statements, whether written or
oral and whether made by or on behalf of Columbia, are also expressly qualified
by these cautionary statements. All forward-looking statements are based on
assumptions that management believes to be reasonable; however, there can be no
assurance that actual results will not differ materially. Realization of
Columbia's objectives and expected performance is subject to a wide range of
risks and can be adversely affected by, among other things, competition,
weather, regulatory and legislative changes as well as changes in general
economic and capital and commodity market conditions many of which are beyond
the control of Columbia. In addition, the relative contributions to
profitability by segment, and the assumptions underlying the forward-looking
statements relating thereto, may change over time.

With respect to any references made to ratings assigned to Columbia's debt
securities, there can be no assurance that Columbia will be successful at
maintaining its credit quality or that such credit ratings will continue for any
given period of time or that they will not be revised downward or withdrawn
entirely by these rating agencies. Credit

                                       5
<PAGE>   6
ITEM 1. BUSINESS (Continued)
ratings reflect only the views of the rating agencies, whose methodology and the
significance of their ratings may be obtained from them.

Other Relevant Business Information
Columbia Group's customer base is broadly diversified, with no single customer
accounting for a significant portion of revenues.

As of February 28, 1999, the Columbia Group had 8,564 full-time employees of
which 1,715 are subject to collective bargaining agreements.

Columbia's subsidiaries are subject to extensive federal, state and local laws
and regulations relating to environmental matters. These laws and regulations,
which are constantly changing, require expenditures for corrective action at
various operating facilities, waste disposal sites and former gas manufacturing
sites for conditions resulting from past practices that have subsequently become
subject to environmental regulation. Information relating to environmental
matters is detailed in Item 7, pages 24 and 29, and in Item 8, Note 13(H) on
page 62.

For a listing of the direct subsidiaries of Columbia refer to Exhibit 21.

                                       6
<PAGE>   7
ITEM 2.  PROPERTIES

Information relating to properties of subsidiary companies is detailed below and
on page 8 and page 48 of Item 8 under Note 1(F). Assets under lien and other
guarantees are described on page 61 in Note 13D of Item 8.

Neither Columbia nor any subsidiary knows of material defects in the title to
any real properties of the subsidiaries of Columbia or any material adverse
claim of any right, title, or interest therein, pending or contemplated.
Substantially all of Columbia Transmission's property has been pledged to
Columbia as security for First Mortgage Bonds issued by Columbia Transmission to
Columbia.


                        EXPLORATION AND DEVELOPMENT DATA

Acreage - at December 31, 1998

<TABLE>
<CAPTION>
                            Developed Acreage                       Undeveloped Acreage        
                         ----------------------                  ----------------------
                         Gross              Net                  Gross              Net
                         -----              ---                  -----              ---
<S>                      <C>                <C>                  <C>                <C>
United States ..         1,431,245          1,407,557            842,405            721,999
Canada .........                --                 --              5,432              4,002
                         ---------          ---------            -------            -------
Total ..........         1,431,245          1,407,557            847,837            726,001
                         =========          =========            =======            =======
</TABLE>


Net Wells Completed - 12 Months Ended December 31,

<TABLE>
<CAPTION>
                          Exploratory             Development                   Total          
                    -------------------      --------------------     ---------------------
                    Productive      Dry      Productive       Dry     Productive(a)     Dry
                    ----------      ---      ----------       ---     -------------     ---
<S>                 <C>             <C>      <C>              <C>     <C>              <C>
United States ..
     1998 ......         5            1          136           32          141           33
     1997 ......        --           --           84           18           84           18
     1996 ......        --           --           19           18           19            8
Canada .........
     1998 ......        --            1           --            1           --            2
</TABLE>


Productive and Drilling Wells - At December 31, 1998

<TABLE>
<CAPTION>
                                           Production Wells             
                       ------------------------------------------------------
                                Gross                            Net                       Wells Drilling       
                       -----------------------          ---------------------            ------------------
                       Gas                 Oil          Gas               Oil            Gross          Net
                       ---                 ---          ---               ---            -----          ---
<S>                    <C>                 <C>          <C>               <C>            <C>            <C>
United States ..       7,059(b)            126          6,650             72             84             61
Canada .........          14                11              7              5              4              3
                                           ---          -----             --             --             --
Total ..........       7,073               137          6,657             77             88             64
                       =====               ===          =====             ==             ==             ==
</TABLE>

(a)  Includes 1 net horizontal well in 1996.
(b)  Includes 600 multiple completion gas wells, all of which are included as
     single wells in the table. Also includes 1 gross productive horizontal
     well.

                                       7
<PAGE>   8
ITEM 2.  PROPERTIES (continued)

            GAS PROPERTIES OF SUBSIDIARIES - AS OF DECEMBER 31, 1998


<TABLE>
<CAPTION>
                                                                                                Miles of Pipeline
                                                         Underground Storage    ------------------------------------------------
                                              -----------------------------      Gathering                                      
       Subsidiaries                           State   Acreage         Wells     and Storage       Transmission     Distribution 
       ------------                           -----   -------         -----     -----------       ------------     ------------ 
<S>                                           <C>     <C>             <C>       <C>               <C>              <C>
Columbia Gas of Kentucky, Inc.                  KY          -             -           -                  -            2,404      
Columbia Gas of Maryland, Inc.                  MD          -             -           -                  -              595      
Columbia Gas of Ohio, Inc.                      OH          -             -           -                  -           18,140      
Columbia Gas of Pennsylvania, Inc.              PA      3,300             8           4                  -            6,895      
Columbia Gas of Virginia, Inc.                  VA          -             -           -                  -            3,960      
Columbia Gas Transmission Corporation           DE          -             -           -                  3                -      
                                                KY          -             -           2                711                -      
                                                MD        945             -           5                229                -      
                                                NJ          -             -           -                 69                -      
                                                NY     26,084           143          55                486                -      
                                                NC          -             -           -                  1                -      
                                                OH    486,517         2,472         972              4,028                -      
                                                PA     63,268           240         570              2,045                -      
                                                VA          -             -           -              1,123                -      
                                                WV    294,268           809         715              2,445                -      
Columbia Gulf Transmission Company              AR          -             -           -                  8                -      
                                                KY          -             -           -                716                -      
                                                LA          -             -           -              1,480                -      
                                                MS          -             -           -                659                -      
                                                TN          -             -           -                556                -      
                                                TX          -             -           -                 44                -      
                                                WY          -             -           -                 10                -      
Columbia Energy Resources, Inc.                 KY          -             -       1,882                  -                -      
                                                MI          -             -           6                  -                -      
                                                NY          -             -          34                  -                -      
                                                OH          -             -         118                  -                -      
                                                PA          -             -          37                  -                -      
                                                TN          -             -           -                  -                -      
                                                VA          -             -         394                  -                -      
                                                WV          -             -       2,539                  -                -      
Columbia Pipeline Company                       DE          -             -           3                  -                -      
Columbia LNG Corporation                        MD          -             -           -                 48                -      
                                                VA          -             -           -                 39                -      
                                                      -------         -----       -----             ------           ------      
Total                                                 874,382         3,672       7,336             14,700           31,994      
                                                      =======         =====       =====             ======           ======      
</TABLE>





<TABLE>
<CAPTION>
                                                  Compressor Stations
                                              ----------------------------
                                                              Installed
       Subsidiaries                           Number         Capacity (hp)
       ------------                           ------         -------------
<S>                                           <C>            <C>
Columbia Gas of Kentucky, Inc.                  -                     -
Columbia Gas of Maryland, Inc.                  -                     -
Columbia Gas of Ohio, Inc.                      -                     -
Columbia Gas of Pennsylvania, Inc.              1                   800
Columbia Gas of Virginia, Inc.                  -                     -
Columbia Gas Transmission Corporation           -                     -
                                                7                18,270
                                                1                12,000
                                                -                     -
                                                4                 6,040
                                                1                 1,200
                                               27               102,532
                                               27                68,913
                                               11                79,480
                                               45               311,874
Columbia Gulf Transmission Company              -                     -
                                                2                70,000
                                                5               192,500
                                                3               121,400
                                                2                85,600
                                                -                     -
                                                -                     -
Columbia Energy Resources, Inc.                 6                   210
                                                -                     -
                                                -                     -
                                                1                    10
                                                -                     -
                                                2                   100
                                                -                     -
                                                7                   211
Columbia Pipeline Company                       -                     -
Columbia LNG Corporation                        -                     -
                                                -                     -
                                              ---             ---------
Total                                         152             1,071,140
                                              ===             =========
</TABLE>

NOTE:         This table excludes minor gas properties and all construction work
              in progress. The titles to the real properties of the subsidiaries
              of Columbia have not been examined for the purpose of this
              document. Neither Columbia nor any subsidiary know of material
              defects in the title to any of the real properties of the
              subsidiaries of Columbia or of any material adverse claim of any
              right, title, or interest therein, pending or contemplated.
              Substantially all of Columbia Transmission's property has been
              pledged to Columbia as security for First Mortgage Bonds issued by
              Columbia Transmission to Columbia.

                                       8
<PAGE>   9
I.   Purchase and Production Matters
A.   Estimation Proceedings. Claims by certain producers for damages resulting
     from the rejection of gas purchase contracts remain unresolved as discussed
     in Item 7, Management's Discussion and Analysis of Financial Condition and
     Results of Operations section of this Report.

B.   New Ulm and Fox v. Mobil Oil Corp., Columbia Gas Transmission Corp. and
     Columbia Gulf Transmission Co., C.A. No. 88-V-655 (155th Judicial Dist. Ct.
     of Austin County, TX). As reported in the Annual Report on Form 10-K for
     1997, Columbia Transmission and New Ulm settled the litigation and New
     Ulm's claims for a proposed allowed amount of $2.25 million in December
     1997, subject to Columbia Transmission's Plan of Reorganization. The
     Bankruptcy Court approved the settlement on January 26, 1998. This matter
     is now concluded.

C.   New Bremen Corp. v. Columbia Gas Transmission Corp. and Columbia Gulf
     Transmission Co., No. 88V-631 (Dist. Ct. Austin County, TX); In re The
     Columbia Gas System, Inc. and Columbia Gas Transmission Corporation, No.
     91-803 and No. 91-804 (U.S. Bankr. Ct. Dist. of Del.). On November 16,
     1988, New Bremen filed a complaint alleging it is entitled to a higher
     price than the market-out price Columbia Transmission paid for past periods
     under the same gas purchase contract price provision involved in the New
     Ulm case discussed above. On January 10, 1989, Columbia Transmission
     removed the case to the United States District Court for the Southern
     District of Texas (No. H-89-0072).

     By order entered December 7, 1992, the Bankruptcy Court modified the
     automatic stay provided under the Bankruptcy Code to allow the U.S.
     District Court to decide the pending motions for summary judgment regarding
     a contract interpretation issue raised by both parties. Other issues raised
     by New Bremen's claim and Columbia Transmission's response thereto were
     referred to the claims mediator. On August 11, 1995, an order was entered
     granting Columbia Transmission's motion for partial summary judgment and
     denying New Bremen's motion for partial summary judgment on the issue of
     contract interpretation. On August 29, 1995, the U.S. District Court denied
     New Bremen's motion to withdraw and set aside its August 11, 1995 order,
     but stated that it would withdraw and vacate its order if the Bankruptcy
     Court determined that it was in violation of the automatic stay. On
     November 2, 1995, the Bankruptcy Court denied New Bremen's motion for an
     order that the August 11, 1995 order was a violation of the automatic stay.
     The U.S. District Court, on March 12, 1996, acting upon a motion filed by
     Columbia Transmission, entered an order finding that there was no just
     reason to delay entry of judgment and therefore entered final judgment of
     its August 11, 1995 order which granted Columbia Transmission's motion for
     partial summary judgment.

     New Bremen appealed the U.S. District Court's grant of partial summary
     judgment to the U.S. Court of Appeals for the Fifth Circuit. On February
     10, 1997, the Fifth Circuit denied New Bremen's appeal and upheld the U. S.
     District Court's grant of partial summary judgment in favor of Columbia
     Transmission on the contract pricing issue. On February 3, 1997, the claims
     mediator issued a recommendation as to issues not resolved by the decisions
     of the U. S. District Court and the Fifth Circuit Court of Appeals. On
     February 25, 1997, Columbia Transmission filed a motion with the Bankruptcy
     Court seeking to have New Bremen's claim allowed by the Bankruptcy Court in
     accordance with the Fifth Circuit decision and the claims mediator's report
     and recommendations issued in the claims estimation proceedings (resolving
     issues not covered by the Fifth Circuit decision).

     On July 24, 1998, the Bankruptcy Court entered an Order allowing the claim
     of New Bremen Corporation in accordance with the Claims Mediator's Report
     and Recommendations and the decision of the U.S. Fifth Circuit Court of
     Appeals. New Bremen failed to file a timely notice of appeal. On August 21,
     1998, New Bremen filed a motion to extend its time for filing on the
     grounds of excusable neglect. On August 24, 1998, the Bankruptcy Court
     granted the motion and provided 10 days for New Bremen to file a notice of
     appeal. On August 28, 1998, New Bremen filed a notice of appeal to the U.S.
     District Court for the District of Delaware. The parties have executed a
     settlement agreement, subject to approval by the Bankruptcy Court. The
     completion of the briefing of the appeal has been adjourned until April 30,
     1999, to allow for Bankruptcy Court approval of the settlement.

II.  Environmental

A.   Columbia Gas Transmission Corp. v. Aetna Casualty & Surety Co., et al.,
     C.A. No. 94-C-454 (Kanawha (W.Va.) Cir. Ct. March 14, 1994). Columbia
     Transmission filed a complaint in West Virginia state court seeking
     coverage from various insurers under various insurance policies for
     environmental cleanup costs. These costs are discussed more fully in the
     Management's Discussion and Analysis of Financial Condition and Results of
     Operations section of this Report. All insurers have responded to the
     complaint denying such claims. The case is currently stayed under the
     evergreen provision of the agreed scheduling order entered by the state
     court on November 29, 1995, in order to allow informal discussions among
     the parties to the litigation. The parties have also entered into an agreed
     order concerning a special discovery master which was entered by the

                                       9
<PAGE>   10
     court. Columbia Transmission continues to pursue recovery of environmental
     expenditures from its insurance carriers, however, at this time, management
     is unable to determine the total amount or final disposition of any
     recovery.

B.   Columbia Gulf Transmission Co. v. Aetna Casualty & Surety Co., et al., C.A.
     No. 95-C-177 (Kanawha (W.Va.) Cir. Ct. January 19, 1995). Columbia Gulf
     filed a complaint in West Virginia state court seeking coverage from
     various insurers under various insurance policies for environmental cleanup
     costs. These costs are discussed more fully in the Management's Discussion
     and Analysis of Financial Condition and Results of Operations section of
     this Report. All insurers have responded to the complaint denying such
     claims. The case is currently stayed under the evergreen provision of the
     agreed scheduling order entered by the state court on December 1, 1995, in
     order to allow informal discussions among the parties to the litigation.
     The parties have also entered into an agreed order concerning a special
     discovery master which was entered by the court. Columbia Gulf continues to
     pursue recovery of environmental expenditures from its insurance carriers,
     however, at this time, management is unable to determine the total amount
     or final disposition of any recovery.

III. Other
A.   Canada Southern Petroleum Ltd. v. Columbia Gas Development of Canada Ltd.
     (C.A. No. 9001-03466, Court of Queen's Bench, Alberta, Canada, filed March
     7, 1990). The plaintiffs assert, among other things, that the defendant
     working interest owners, including Columbia Gas Development of Canada Ltd.
     (Columbia Canada) and various Amoco affiliates, breached an alleged
     fiduciary duty to ensure the earliest feasible marketing of gas from the
     Kotaneelee field (Yukon Territory, Canada). The plaintiffs seek, among
     other remedies, the return of the defendants' interests in the Kotaneelee
     field to the plaintiffs, a declaration that such interests are held in
     trust for the plaintiffs and an order requiring the defendants to promptly
     market Kotaneelee gas or assessing damages.

     In November 1993, the plaintiffs amended their Amended Statement of Claim
     to include allegations that the balance in the Carried Interest Account (an
     account for operating costs which are recoverable by working interest
     owners) which is in excess of the balance as of November 1988 should be
     reduced to zero. Columbia, on behalf of Columbia Canada, consented to the
     amendment in consideration of the plaintiffs' acknowledgment that some $63
     million was properly charged to the account. However, Columbia and Columbia
     Canada continue to dispute the claim to the extent that the claim
     challenges expenditures incurred since November 1988, including
     expenditures made after Columbia Canada was sold to Anderson Exploration
     Ltd. (Anderson) effective December 31, 1991.

     A trial commenced in the third quarter of 1996 in the Court of Queen's
     Bench. Following multiple lengthy adjournments, plaintiffs concluded their
     case-in-chief in the fourth quarter of 1998. Defendants are currently
     presenting their witnesses and evidence. Due to the complex nature of the
     litigation, Columbia cannot predict the length of the trial. Management
     continues to believe that its defenses are meritorious, and that the risk
     of any material liability to Columbia is de minimis.

     Pursuant to an Indemnification Agreement regarding the Kotaneelee
     Litigation entered into when Columbia Canada was sold to Anderson, Columbia
     agreed to indemnify and hold Anderson harmless for losses due to this
     litigation arising out of actions occurring prior to December 31, 1991. As
     a result of the 1997 upgrading of Columbia's long-term debt, an escrow
     account that provides security for the indemnification obligation and is
     now funded by a letter of credit was reduced to approximately $35,835,000
     (Cdn).

B.   Cathodic Protection. In September 1995, the management of Commonwealth Gas
     Services, Inc. (now Columbia Gas of Virginia, Inc.) (Columbia of Virginia)
     advised the Staff of the Virginia State Corporation Commission (VSCC) that
     there had been deficiencies in Columbia of Virginia's cathodically
     protected pipeline distribution system in its Northern Operating Area in
     Virginia. Following several months of informal investigation, on March 1,
     1996, the Commission issued a subpoena for Columbia of Virginia to produce
     documents related to its cathodic protection program in the Northern
     Operating Area. Columbia of Virginia complied with the subpoena. On
     November 18, 1998, Columbia of Virginia reported to the VSCC that, with one
     small exception, it had completed all remedial work related to the cathodic
     protection deficiencies. At this time Columbia is unable to determine the
     likelihood or magnitude of any penalties that might be assessed.

C.   MarkWest Hydrocarbon, Inc., Arbitration Proceeding, AAA Case No. 77 181
     0035 98 (filed February 13, 1998); Columbia Gas Transmission Corp. v.
     MarkWest Hydrocarbon, Inc., U.S. D.C., S.D. W.Va., Case No. 2:98-03622
     (filed April 28, 1998). In the Settlement of Columbia Transmission's last
     rate case in Docket No. RP95-408, approved by the FERC on April 17, 1997,
     Columbia Transmission, MarkWest Hydrocarbon, Inc. (MarkWest) and other
     parties agreed that Columbia Transmission's gathering and products
     extraction rates and

                                       10
<PAGE>   11
     services would be "unbundled" in compliance with Order No. 636 and that
     MarkWest would acquire Columbia Transmission's interests in certain
     products extraction facilities and provide gas processing services to
     certain shippers on Columbia Transmission's system. In February 1998,
     negotiations surrounding the transfer of facilities and processing services
     to MarkWest reached an impasse, resulting in an arbitration proceeding and
     a court proceeding, both of which are discussed below. Columbia
     Transmission believes MarkWest's claims are essentially without merit, and
     that any financial consequence to Columbia Transmission will not be
     material. On September 16, 1998, the FERC issued an order pursuant to which
     Columbia Transmission will retain certain quantities of gas from its
     customers through its retainage adjustment mechanism but not deliver those
     quantities to MarkWest pending resolution of the court and arbitration
     proceedings. On December 7, 1998, MarkWest and Columbia Transmission
     entered into a "standstill" agreement under which the parties essentially
     agreed to continue the current operational status quo until the earlier of
     a ruling by the Panel (as defined below) or July 1, 1999.

     Arbitration Proceeding. On February 13, 1998, MarkWest filed a demand for
     arbitration. In response to Columbia Transmission's request, the
     Arbitration Panel (Panel), by orders dated June 10 and June 16, 1998,
     directed MarkWest to file a more specific statement of the claims to be
     arbitrated and to explain why the claims are arbitrable. MarkWest filed an
     Amended Demand for Arbitration on June 19, wherein MarkWest seeks an order,
     inter alia, declaring that certain pre-settlement agreements between
     Columbia Transmission and MarkWest have not terminated and that specific
     performance by Columbia Transmission is required. MarkWest also alleged
     tortious interference with its existing and prospective contracts,
     fraudulent concealment, misrepresentation and civil conspiracy by Columbia
     Transmission, Columbia and Columbia Resources to interfere with MarkWest's
     business. MarkWest seeks compensatory damages for past and future losses in
     an amount not less than $391.6 million as well as exemplary damages.
     Columbia Transmission answered and filed contingent counterclaims on July 2
     and contested the arbitrability of all but three issues. On July 29, 1998,
     the Panel issued an order whereby it found to be non-arbitrable all of
     MarkWest's claims except those that relate to obligations arising directly
     under two of the parties' agreements, some of which Columbia Transmission
     agreed were subject to arbitration. On October 30, 1998, the Panel issued
     its New Ruling on Arbitrable Issues and Vacation of Ruling of July 29,
     1998. The ruling was issued in response to the U.S. District Court's order
     dated August 3, 1998. The panel held that certain claims regarding contract
     interpretation, asserted contractual obligations, and asserted breach
     thereof arising under six specific agreements, including the Settlement
     Agreement in RP95-408, are arbitrable. The Panel reaffirmed its earlier
     ruling that dismissed MarkWest's tortious interference, fraudulent
     concealment, misrepresentation and civil conspiracy claims described above
     as being non-arbitrable. The Panel's decision will reduce, by an amount
     Columbia Transmission cannot determine, MarkWest's alleged damages.
     Although a hearing has not yet been held, the Panel has ruled that, with
     respect to certain additional issues, it will hear evidence and argument
     before ruling on arbitrability.

     Court Proceeding. Columbia Transmission filed a complaint against MarkWest
     on April 28, 1998, in Federal District Court for the Southern District of
     West Virginia seeking, inter alia, (i) a declaratory order that certain gas
     processing agreements are terminated in whole or in part, (ii) a
     declaratory order that MarkWest has breached the Settlement of Docket No.
     RP95-408, and (iii) an injunction against MarkWest interfering with
     Columbia Transmission's efforts to spin off its products extraction
     business. On August 3, 1998, the U.S. District Court issued a memorandum
     opinion and order granting MarkWest's motion to stay proceedings and compel
     arbitration.

                                       11
<PAGE>   12
ITEM 4.    SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

None

                                     PART II

ITEM 5. MARKET FOR THE REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER
        MATTERS

The common stock of Columbia is traded on the New York Stock Exchange under the
ticker symbol CG and is abbreviated as either ColumEngy or ColumEgy in trading
reports. The number of record shareholders on December 31, 1998, was
approximately 35,261 and the stock closed at $57.75 on December 31, 1998, as
reflected in the New York Stock Exchange Composite Transactions as reported by
The Wall Street Journal. On February 17, 1999, Columbia declared a quarterly
dividend of $0.20 per share for the first quarter of 1999, which was declared
payable on or about March 15, 1999, to holders of record on March 1, 1999.

See Item 7 on page 21 for additional information regarding Columbia's common
stock prices and dividends.

                                       12
<PAGE>   13
ITEM 6.  SELECTED FINANCIAL DATA 
                            Selected Financial Data
                     Columbia Energy Group and Subsidiaries

<TABLE>
<CAPTION>
($ in millions, except per share amounts)                 1998         1997         1996         1995*          1994*         1993*
- -----------------------------------------------------------------------------------------------------------------------------------
<S>                                                    <C>            <C>          <C>          <C>             <C>          <C>
INCOME STATEMENT DATA($) 
 Total net revenues                                     1,897.1        1,915.5      1,872.9     1,814.6         1,762.9      1,736.1
 Earnings (Loss) before extraordinary item                
  and accounting changes                                  269.2          273.3        221.6      (432.3)          246.2        152.2
 Earnings (Loss) on common stock                          269.2          273.3        221.6      (360.7)          240.6        152.2
- ------------------------------------------------------------------------------------------------------------------------------------
PER SHARE DATA**
 Earnings (Loss) per share of common stock($):
  Before extraordinary item and accounting changes        3.23            3.29         2.75       (5.71)           3.25         2.01
  Earnings (Loss) per share of common stock               3.23            3.29         2.75       (4.76)           3.17         2.01
 Average common shares outstanding(000)                 83,382          83,100       80,681      75,708          75,838       75,838
 Diluted earnings (loss) per share of common stock($):
  Before extraordinary item and accounting changes        3.21            3.27         2.74       (5.71)          3.25          2.01
  Diluted earnings (loss) per share of common stock       3.21            3.27         2.74       (4.76)          3.17          2.01
 Diluted average common shares(000)                     83,748          83,594       80,919      75,708         75,838        75,838
 Dividends:
  Per share($)                                            0.77            0.60         0.40          -             -               -
  Payment ratio(%)                                        23.8            18.2         14.5         N/A           N/A            N/A
- ------------------------------------------------------------------------------------------------------------------------------------
BALANCE SHEET DATA($)
 Capitalization including debt subject to Chapter 11:
  Common stock equity                                  2,005.3         1,790.7      1,553.6     1,114.0        1,468.0       1,227.3
  Preferred stock                                            -               -            -       399.9              -             -
  Long-term debt                                       2,003.1         2,003.5      2,003.8     2,004.5            4.3           4.8
  Short-term debt                                          N/A             N/A          N/A         N/A              -             -
  Current maturities of long-term debt                     0.4             0.5          0.8         0.5            1.2           1.3
  Debt subject to Chapter 11                                 -               -            -           -        2,317.1       2,317.1
  Total                                                4,008.8         3,794.7      3,558.2      3,518.9       3,790.6       3,550.5
 Total assets                                          6,968.7         6,612.3      6,004.6      6,057.0       7,164.9       6,957.9
- ------------------------------------------------------------------------------------------------------------------------------------
OTHER FINANCIAL DATA
 Capitalization ratio(%)(including current maturities***):
  Common stock equity                                    50.0             47.2         43.7         31.7           38.7         34.6
  Preferred stock                                           -                -            -         11.4              -            -
  Debt                                                   50.0             52.8         56.3         56.9            61.3        65.4
 Capital expenditures($)                                478.7            560.3        314.8        421.8           447.2       361.3
 Net cash from operations($)                            761.7            468.2        477.0       (804.1)          572.8       850.4
 Book value per share of common stock($)**              24.01            21.51        18.74        15.09           19.36       16.18
 Return on average common equity
  before extraordinary item and accounting changes(%)    14.2             16.3         16.6        (33.5)           18.3        13.2
- ------------------------------------------------------------------------------------------------------------------------------------
</TABLE>



N/A - Not applicable 

Dilutive potential common shares were not included in the 1995 computation of
diluted EPS as the effect would be antidilutive. 

* Reference is made to Note 13(A) of Notes to Consolidated Financial Statements.
   Due to the bankruptcy filings, interest expense of approximately $230
   million, $210 million, $204 million and $86 million was not recorded in 1994,
   1993, 1992 and 1991, respectively. Interest expense of $982.9 million
   including write-off of unamortized discounts on debentures, was recorded in
   the fourth quarter of 1995.
 
** All per share amounts, average common shares outstanding and diluted average
    common shares have been restated to reflect a three-for-two common stock
    split, in the form of a stock dividend, effective June 15, 1998.

*** Prior to 1991, Columbia made extensive use of variable rate debt since the
     associated cost was normally less than our senior long-term debt. Inclusion
     of the short-term debt in years prior to 1991 makes those historical ratios
     more meaningful.



                                       13
<PAGE>   14
ITEM 6.  SELECTED FINANCIAL DATA (continued)

                             SELECTED FINANCIAL DATA
                     Columbia Energy Group and Subsidiaries

<TABLE>
<CAPTION>
($ in millions, except per share amounts)                                 1992*       1991*         1990        1989        1988
- --------------------------------------------------------------------------------------------------------------------------------
<S>                                                                     <C>         <C>          <C>         <C>         <C>
INCOME STATEMENT DATA ($)
   Total net revenues                                                   1,622.3     1,407.2      1,499.9     1,520.3     1,335.2
   Earnings (Loss) before extraordinary item
      and accounting changes                                               90.9      (794.8)       104.7       145.8       119.0
   Earnings (Loss) on common stock                                         51.2      (694.4)       104.7       145.8       111.1
- --------------------------------------------------------------------------------------------------------------------------------

PER SHARE DATA**
   Earnings (Loss) per share of common stock ($):
      Before extraordinary item and accounting changes                     1.20      (10.49)        1.48        2.14        1.64
      Earnings (Loss) per share of common stock                            0.68       (9.16)        1.48        2.14        1.64
   Average common shares outstanding (000)                               75,838      75,798       70,983      68,260      67,809
   Diluted earnings (loss) per share of common stock ($):
      Before extraordinary item and accounting changes                     1.20      (10.49)        1.47        2.13        1.64
      Diluted earnings (loss) per share of common stock                    0.68       (9.16)        1.47        2.13        1.64
   Diluted average common shares (000)                                   75,838      75,798       71,133      68,537      67,809
   Dividends:
      Per share ($)                                                           -        0.77         1.47        1.33        1.53
      Payout ratio (%)                                                      N/A         N/A         99.3        62.1        93.3
- --------------------------------------------------------------------------------------------------------------------------------

BALANCE SHEET DATA ($)
   Capitalization including debt subject to Chapter 11:
      Common stock equity                                               1,075.1     1,006.9      1,757.8     1,620.3     1,552.6
      Preferred stock                                                         -           -            -           -           -
      Long-term debt                                                        5.4         6.1      1,428.7     1,196.0     1,038.4
      Short-term debt                                                         -         N/A        735.5       634.2       697.1
      Current maturities of long-term debt                                  1.4         2.9         35.2        47.2        52.7
      Debt subject to Chapter 11                                        2,317.1     2,317.1            -           -           -
      Total                                                             3,399.0     3,333.0      3,957.2     3,497.7     3,340.8
   Total assets                                                         6,505.9     6,332.2      6,196.3     5,878.4     5,641.0
- --------------------------------------------------------------------------------------------------------------------------------

OTHER FINANCIAL DATA
   Capitalization ratio (%) (including current maturities ***):
      Common stock equity                                                  31.6        30.2         44.4        46.3        46.5
      Preferred stock                                                         -           -            -           -           -
      Debt                                                                 68.4        69.8         55.6        53.7        53.5
   Capital expenditures ($)                                               299.7       381.9        629.6       473.5       307.9
   Net cash from operations ($)                                           765.4       531.6        420.1       400.5       429.4
   Book value per share of common stock ($) **                            14.18       13.28        23.22       23.67       22.79
   Return on average common equity
      before extraordinary item and accounting changes (%)                  8.7       (57.5)         6.2         9.2         7.2
- --------------------------------------------------------------------------------------------------------------------------------
</TABLE>

N/A - Not applicable

Dilutive potential common shares were not included in the 1995 computation of
diluted EPS as the effect would be antidilutive.

*      Reference is made to Note 13(A) of Notes to Consolidated Financial
       Statements. Due to the bankruptcy filings, interest expense of
       approximately $230 million, $210 million, $204 million and $86 million
       was not recorded in 1994, 1993, 1992 and 1991, respectively. Interest
       expense of $982.9 million including write-off of unamortized discounts on
       debentures, was recorded in the fourth quarter of 1995.

**     All per share amounts, average common shares outstanding and diluted
       average common shares have been restated to reflect a three-for-two
       common stock split, in the form of a stock dividend, effective June 15,
       1998.

***    Prior to 1991, Columbia made extensive use of variable rate debt since
       the associated cost was normally less than senior long-term debt.
       Inclusion of the short-term debt in years prior to 1991 makes those
       historical ratios more meaningful.

                                       14
<PAGE>   15
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS


<TABLE>
<CAPTION>
Index                                                                                                  Page
- -----                                                                                                  ----
<S>                                                                                                    <C>
Consolidated Review.............................................................................          15
Liquidity and Capital Resources.................................................................          17
Transmission and Storage Operations.............................................................          22
Distribution Operations.........................................................................          27
Exploration and Production Operations...........................................................          32
Marketing Operations............................................................................          34
Propane, Power Generation and LNG Operations....................................................          37
Bankruptcy Matters..............................................................................          39
</TABLE>

The Management's Discussion and Analysis, including statements regarding market
risk sensitive instruments and in the section "Impact of Year 2000 on Computer
and Other Systems," contains "forward-looking statements," within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. Investors and prospective investors
should understand that many factors govern whether any forward-looking statement
contained herein will be or can be achieved. Any one of those factors could
cause actual results to differ materially from those projected. These
forward-looking statements include, but are not limited to, statements
concerning Columbia's plans, objectives, expected performance, expenditures and
recovery of expenditures through rates, stated on either a consolidated or
segment basis, and any and all underlying assumptions and other statements that
are other than statements of historical fact. From time to time, Columbia may
publish or otherwise make available forward-looking statements of this nature.
All such subsequent forward-looking statements, whether written or oral and
whether made by or on behalf of Columbia, are also expressly qualified by these
cautionary statements. All forward-looking statements are based on assumptions
that management believes to be reasonable; however, there can be no assurance
that actual results will not differ materially. Realization of Columbia's
objectives and expected performance is subject to a wide range of risks and can
be adversely affected by, among other things, competition, weather, impact of
the year 2000 on computer, operating and other systems, regulatory and
legislative changes as well as changes in general economic, capital and
commodity market conditions, many of which are beyond the control of Columbia.
In addition, the relative contributions to profitability by each segment, and
the assumptions underlying the forward-looking statements relating thereto, may
change over time. With respect to Columbia's year 2000 program, the dates on
which Columbia believes it will be completed are based on management's best
estimates, which were derived utilizing numerous assumptions of future events.
However, there can be no guarantee that these estimates will be achieved, or
that there will not be a delay in, or increased costs associated with, the
implementation of the year 2000 program. Specific factors that might cause
differences between the estimates and actual results include, but are not
limited to, the availability and cost of personnel trained in these areas, the
ability to timely locate and correct all relevant computer codes for both
information technology (IT) and non-IT systems, the nature and amount of
programming and testing required to upgrade or replace IT and non-IT systems,
timely responses to, and corrections by, third-parties and suppliers, the
ability to implement interfaces between, and among, IT and non-IT systems for
which remediation or an upgrade is performed, the nature and amount of testing,
verification and reporting required by relevant government regulatory
authorities, including federal and state utility regulatory bodies, and other
similar uncertainties.

With respect to any references made to ratings assigned to Columbia's debt
securities, there can be no assurance that Columbia will be successful in
maintaining its credit quality, or that such credit ratings will continue for
any given period of time, or that they will not be revised downward or withdrawn
entirely by the rating agencies. Credit ratings reflect only the views of the
rating agencies, whose methodology and the significance of their ratings may be
obtained from them.

                               CONSOLIDATED REVIEW

Net Income
Columbia Energy Group reported net income for 1998 of $269.2 million, or $3.23
per share, a decrease of $4.1 million, or 6 cents per share, from 1997.

The decrease was due largely to the impact of record warm weather in 1998 and
the costs of Columbia's continued investment in its marketing segment. These
decreases were largely offset by lower operation and maintenance costs for
Columbia's rate-regulated subsidiaries, higher revenue from transportation
services and gas management activities and increased gas production and prices
from Columbia's exploration and production segment.

Several other key items also affected both years' results. In 1998, a $16.5
million benefit from the reduction in certain postretirement benefit costs,
reflecting the purchase of insurance for a portion of those liabilities, and a
$10 million benefit from state tax planning initiatives enhanced net income.
Also improving 1998 results was a gain of

                                       15
<PAGE>   16
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

$6.5 million from the settlement of 1991-1994 tax issues. In 1997, net income
was improved $12.8 million as a result of reduced state income taxes, $12.4
million from a regulatory settlement for Columbia Gas Transmission Corporation
(Columbia Transmission) that included the sale of base gas storage volumes, $6
million from the sale of coal assets, $5.5 million from a gain on the
deactivation of a storage field and $4.4 million for payments received from a
cogeneration partnership. Reducing net income in 1997 were $20.2 million of
restructuring and relocation costs and a $6.6 million reserve for the sale of
certain pipeline facilities.

Columbia's 1997 net income was $273.3 million, or $3.29 per share, up $51.7
million, or 54 cents per share, over 1996. After adjusting for unusual items,
this improvement was due in large part to lower operating costs for the
regulated subsidiaries and increased revenues from transportation and storage
services and gas management activities.

Net Revenues
Total net revenues (revenues less associated product purchased costs) of
$1,897.1 million for 1998, reflected a decrease of $18.4 million from 1997, due
primarily to the adverse effect of warmer weather in 1998 on gas sales for the
distribution segment. The impact of warmer weather was partially offset by a
$22.1 million increase in the marketing segment's gross margin due to higher gas
sales and the addition of electric power sales in 1998, as well as higher
revenues from transportation services and gas management activities in the
transmission and distribution segments. Also improving revenues in 1998 was a
$13.4 million increase resulting from the gain on the sale of storage base gas
volumes and higher revenues from increased gas production and prices. Natural
gas sales for Columbia's marketing segment in 1998 totaled 1,581 Billion cubic
feet (Bcf), nearly twice the level for the same period last year, while its 1998
electric power sales were 14,364 Gigawatt hours.

In 1997, total net revenues were $1,915.5 million, an increase of $42.6 million
over 1996. The higher net revenues were principally due to increased sales by
the marketing segment and higher rates in effect for the distribution segment
for the recovery of increased gas costs. Also improving revenues were the
effects of regulatory settlements reached in 1997 for Columbia Transmission and
Columbia Gas of Ohio, Inc. (Columbia of Ohio) and increased off-system sales,
transportation and storage services.

Expenses
Total operating expenses of $1,357.1 million for 1998 decreased $49 million
compared to 1997, largely reflecting a reduction of $60.7 million in operation
and maintenance expense. The reduction took place despite $64.6 million of
higher operation and maintenance expenses for the marketing segment to build
infrastructure, add and retain qualified staff and record a reserve stemming
from the continuing review of that segment's financial records. The lower
operation and maintenance expense was primarily the result of a $25.4 million
reduction in the cost of certain postretirement benefits, reflecting the
purchase of insurance for a portion of Columbia's liabilities. The 1997
operating expenses were higher due in part to $24.8 million of restructuring
costs. The transmission and storage segment's and the distribution segment's
operation and maintenance expense also decreased in 1998 as a result of cost
conservation measures and efficiencies gained through recently implemented
restructuring activities. Overall depreciation and depletion expense increased
$13.9 million due primarily to an increase in depletion expense for the
exploration and production segment resulting from a higher depletion rate,
together with the effect of increased production from both the acquisition of
Alamco, Inc. (Alamco), an Appalachian exploration and production company in
1997, and the success of Columbia Energy Resources Inc.'s (Columbia Resources)
drilling program.

Operating expenses for 1997 of $1,406.1 million were $11.4 million higher than
for 1996. Despite acquisitions made in 1997 and higher startup costs for new
services, Columbia's 1997 operation and maintenance expense decreased $3.6
million from 1996. Total operating expenses for the marketing segment rose $21.8
million due in large part to expanding the marketing segment's operations
through the acquisition of PennUnion Energy Services L.L.C. (PennUnion) and
building the segment's infrastructure to support its growth. Operation and
maintenance costs for the rate-regulated subsidiaries decreased, after adjusting
for 1997 restructuring costs and a reserve of $10.1 million for the sale of
certain pipeline facilities in New York and Pennsylvania, reflecting the
beneficial effect of implementing restructuring initiatives.

                                       16
<PAGE>   17
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

Other Income (Deductions)

<TABLE>
<CAPTION>
Twelve Months Ended December 31, (in millions)               1998              1997              1996
- ------------------------------------------------------------------------------------------------------
<S>                                                     <C>               <C>               <C>
   Interest income and other, net                       $    13.4         $    40.4         $    26.1
   Interest expense and related charges                    (152.4)           (157.6)           (166.8)
- ------------------------------------------------------------------------------------------------------
TOTAL OTHER INCOME (DEDUCTIONS)                         $  (139.0)        $  (117.2)        $  (140.7)
- ------------------------------------------------------------------------------------------------------
</TABLE>

For 1998, Other Income (Deductions) reduced income by $139 million compared to a
reduction of $117.2 million in 1997. Interest income and other, net of $13.4
million decreased $27 million when compared to 1997, due largely to two items
recorded in 1997, namely, an $8.5 million gain for a payment received from the
deactivation of a storage field that allowed the owner of the coal reserves to
mine the property and a $9.5 million improvement for the sale of Columbia's coal
assets. In addition, temporary cash investments in 1998 were lower than the
prior year, which led to reduced interest income. Interest expense and related
charges of $152.4 million in 1998 decreased $5.2 million from 1997, primarily
reflecting a reduction to interest expense for a 1998 tax settlement, involving
tax issues from 1991-1994, partially offset by additional interest expense on
prepayments received from third parties for gas to be delivered in future
periods.

When comparing 1997 to 1996, Other Income (Deductions) reduced income $117.2
million in 1997 and $140.7 million in 1996. The income improvement in 1997 was
largely due to reduced interest expense on short-term borrowings, an $8.5
million pre-tax gain for the payment received from the deactivation of the
storage field and a $9.5 million gain from the sale of Columbia's coal assets.

Income Taxes 
Income tax expense for 1998 was $131.8 million, up $12.9 million from the year
earlier, primarily reflecting tax benefits recorded in 1997 not available in
1998. In addition, net income benefited from reductions to income tax expense of
approximately $10 million in 1998 and $12.8 million in 1997 due to the
implementation of state tax planning initiatives.

Income tax expense in 1997 increased $3 million over 1996 due to higher income
that was largely offset by the $12.8 million reduction for implementing state
tax planning initiatives, mentioned previously.

                         LIQUIDITY AND CAPITAL RESOURCES

A significant portion of Columbia's operations, most notably in the distribution
segment, is subject to seasonal fluctuations in cash flow. During the heating
season, which is primarily from November through March, cash receipts from sales
and transportation services typically exceed cash requirements. Conversely,
during the remainder of the year, cash on hand, together with external
short-term and long-term financing, is used to purchase gas to place in storage
for heating season deliveries, perform necessary maintenance of facilities, make
capital improvements in plant and expand service into new areas.

Net cash from operations for 1998 was $761.7 million, an increase of $293.5
million over 1997. The increase primarily reflects higher prepayments received
for the future delivery of natural gas by Columbia and working capital changes,
including an increase in accounts payable, offset by a decrease in the
overrecovery of gas costs by the distribution segment as well as the effect of
warm weather in 1998. The decrease in the overrecovery position reflects higher
gas prices in the current period compared to the same period in 1997. The
recovery of gas costs in the distribution segment's rates is provided for under
the current regulatory process.

Net cash from operations in 1997 decreased $8.8 million from 1996 to $468.2
million primarily reflecting higher cash needs for working capital purposes. The
increased use of cash for working capital in 1997 was caused by higher accounts
receivable, offset by the receipt of cash during the year related to income tax
refunds and a switch from being underrecovered to overrecovered for the
distribution segment's gas costs. Tempering these uses of cash was the full
period effect of higher base rates for Columbia Transmission.

Columbia satisfies its liquidity requirements primarily through internally
generated funds and from the sale of commercial paper, which is supported by the
use of two unsecured bank revolving credit facilities that total $1.35 billion
(Credit Facilities). In March 1998, the Credit Facilities replaced the $1
billion five-year revolving credit facility entered into by Columbia in November
1995.

                                       17
<PAGE>   18
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

Columbia's Credit Facilities consist of a $450 million 364-day revolving credit
facility, with a one-year term loan option, that expires in March 2000 and a
$900 million five-year revolving credit facility that expires in March 2003 and
provides for the issuance of up to $300 million of letters of credit.

Interest rates on borrowings under the Credit Facilities are based upon the
London Interbank Offered Rate, Certificate of Deposit rates or other short-term
interest rates. In addition, the 364-day facility has a utilization fee if
borrowings exceed a certain level. The interest rate margins and facility fee on
the commitment amounts are based on Columbia's public debt ratings. During 1998,
Moody's Investors Service, Inc. (Moody's) and Fitch Investors Service (Fitch)
each upgraded their rating of Columbia's long-term debt to A3 and A,
respectively. Columbia's long-term debt rating is BBB+ by Standard & Poor's
Ratings Group (S&P). Under the Credit Facilities, higher debt ratings result in
lower facility fees and interest rate margins on borrowings. Columbia's
commercial paper ratings are F-1 by Fitch, P-2 by Moody's and A-2 by S&P.

As of December 31, 1998, Columbia had $144.8 million of commercial paper
outstanding and approximately $127 million of letters of credit issued, of which
$44.4 million were issued under the Credit Facilities.

During 1998, Columbia entered into fixed-to-floating interest rate swap
agreements to modify the interest characteristics of $300 million of its
outstanding long-term debt. As a result of these transactions, that portion of
Columbia's long-term debt is now subject to fluctuations in interest rates. This
allows Columbia to benefit from a lower interest rate environment. In order to
maintain a balance between fixed and floating interest rates, Columbia is
targeting average floating rate debt exposure of 10-20%.

Columbia has an effective shelf registration statement on file with the U. S.
Securities and Exchange Commission for the issuance of up to $1 billion in
aggregate of debentures, common stock or preferred stock in one or more series.
In March 1996, Columbia issued 5,750,000 shares of common stock under the shelf
registration and used the proceeds to reduce borrowings incurred under the prior
credit facility and, together with other funds, to retire $400 million of
preferred stock issued in late 1995. No further issuances of the remaining $750
million available under the shelf registration are scheduled at this time.

At its February 1999 meeting, Columbia's Board of Directors authorized the
purchase of up to $100 million of Columbia's common stock through February 29,
2000, in the open market or otherwise. The source of funds for repurchases would
consist of available funds or short-term borrowings. The timing and terms of
purchases, and the number of shares actually purchased, will be determined by
management based on market conditions and other factors. Purchased shares will
be held in treasury to be made available for general corporate purposes, or
resale at a future date, or they may be retired.

Management believes that its sources of funding are sufficient to meet
short-term and long-term liquidity needs.

Presentation of Segment Information
Columbia revised its presentation of primary business segment information
beginning with the reporting of second quarter results for 1998. Marketing
operations are now reported in a separate segment rather than the former
marketing, propane and power generation segment. Columbia LNG Corporation's
results are now reported in the propane, power generation and LNG segment,
rather than the transmission and storage segment. Prior periods have been
restated to reflect this change.

Capital Expenditures
The table below reflects actual capital expenditures by segment for 1998 and
1997 and an estimate for 1999:

<TABLE>
<CAPTION>
(in millions)                               1999          1998          1997
- -----------------------------------------------------------------------------
<S>                                        <C>           <C>           <C>
 Transmission and Storage                   $237          $204          $245
 Distribution                                152           152           159
 Exploration and Production                  104            76           136*
 Marketing                                    20            16             5
 Propane, Power Generation and LNG           129            20            10
Corporate                                      8            11             5
- -----------------------------------------------------------------------------
 TOTAL                                      $650          $479          $560
- -----------------------------------------------------------------------------
</TABLE>

  * Does not reflect approximately $23 million of gathering facilities that
    Columbia Transmission sold to Columbia Natural Resources, Inc.

                                       18
<PAGE>   19
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

For 1998, capital expenditures were $479 million, a decrease of $81 million from
1997. The Alamco acquisition represented approximately $101 million of the 1997
program. The 1998 program included $95 million for new business initiatives for
the transmission and storage segment. The largest portion of the transmission
and storage segment's investments are made to ensure the safety and reliability
of the pipelines and for market expansion activities. The distribution
subsidiaries' program includes investments to extend service to new areas and
develop future markets, as well as expenditures required to ensure safe,
reliable and improved service. In 1998, propane acquisitions accounted for about
$19 million of the program.

For 1999, Columbia's estimated capital expenditure program of $650 million is
$171 million higher than the 1998 program. Included for the transmission and
storage segment is approximately $126 million for new business activities, such
as market expansion initiatives, and another $59 million is planned for new
business and development activities for the distribution segment. The
exploration and production segment's capital program provides for the drilling
of approximately 230 new wells. The 1999 program also includes small increases
for normal activities in the marketing segment as well as amounts for potential
acquisitions in the propane, power generation and LNG segment.

All discretionary capital expenditures are subject to review under Columbia's
value added approach (CVA) that determines whether the anticipated return on a
business activity or project exceeds its risk adjusted capital cost.

Market Risk Exposure
Subsidiaries in Columbia's exploration and production, marketing and propane
operations are exposed to market risk due primarily to fluctuations in commodity
prices. In order to help minimize this risk, Columbia has adopted a policy that
provides for commodity trading activities to help ensure stable cash flow,
favorable prices and margins as well as to help capture any long-term increases
in value. Financial instruments authorized for use by Columbia for commodity
trading include futures, swaps and options. Columbia Energy Services utilizes
financial instruments to help assure adequate margins on the purchase and resale
of natural gas and electric power. Columbia Resources also utilizes financial
instruments to fix prices for a portion of its future production volumes. These
positions of Columbia Resources are hedged in the marketplace through Columbia
Energy Services. Columbia Propane utilizes financial instruments to help protect
the value of inventories. See Note 1(G) in Notes to Consolidated Financial
Statements for a discussion of the accounting treatment for derivatives and Note
5 for Risk Management Activities.

In the third quarter of 1998, Columbia's policy was expanded to allow open
trading positions in electric power for its marketing segment operations to take
advantage of market information or strategic opportunities related to
electricity commodity prices and basis. Also in the third quarter, trading
activity in weather derivatives was authorized. Positions in natural gas,
electric power and weather derivatives are controlled within predetermined
limits as provided by Columbia's senior management. Columbia's policy prohibits
any Columbia subsidiary from entering into trading positions that are not
effectively connected with its business. The risks associated with these trading
activities are managed consistent with policies approved by Columbia's Board of
Directors. Market risks are monitored by an independent risk control group
operating separately from the area that creates or actively manages these risk
exposures to ensure compliance with Columbia's stated risk management policies.
Effective January 1, 1999, Columbia adopted mark-to-market accounting for all of
its gas and power marketing operations and marks all physical and financial
positions to market in accordance with the Financial Accounting Standards Board
Emerging Issues Task Force's recently issued Statement 98-10.

Columbia measures the market risk in its portfolios on a daily basis and employs
multiple risk control mechanisms to mitigate market risk including value-at-risk
measures using a variance/covariance methodology, and volumetric limits.
Value-at-risk simulates forward price curves in the energy markets to estimate
the size and probability of future potential losses. Based on a 95% confidence
interval and a one-day time horizon, the value-at-risk for Columbia's commodity
market risk sensitive instruments was approximately $1.8 million as of December
31, 1998, whereas at year-end 1997 the value-at-risk was estimated at $175,000.

Columbia also utilizes fixed-to-floating interest rate swap agreements to modify
the interest characteristics of a portion of its outstanding long-term debt. As
a result of these transactions, that portion of Columbia's long-term debt is now
subject to fluctuations in interest rates.

                                       19
<PAGE>   20
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

Impact of Year 2000 on Computer and Other Systems
The Year 2000 issue is a worldwide concern because many existing computer
programs and certain computer hardware were initially designed without
considering the impact of the change to the year 2000. If not corrected, certain
computer, operating and other systems could fail or create erroneous results.

Columbia is evaluating its IT and non-IT systems to determine if they are year
2000 compliant and, if these systems are not year 2000 compliant, what
corrective action is necessary. IT and non-IT systems that are currently being
identified, tested and, as necessary, corrected or replaced with compliant
systems include: 1) mission critical processes that relate to the safety or
dependability of Columbia's natural gas delivery system and other core business
operations; 2) customer billing, vendor payment, shareholder records and payroll
systems; and 3) other processes relevant to Columbia's continued operations.
Embedded chips and other non-IT hardware that are found to not be year 2000
compliant are being replaced or upgraded as appropriate. To ensure timely
completion of all phases of the year 2000 project, Columbia is utilizing
external consultants with specific year 2000 expertise on certain aspects of the
project.

Columbia's year 2000 program is divided into phases that provide for the timely
assessment, remediation and testing of IT and non-IT systems as appropriate. The
assessment phase, which was completed as of December 31, 1998, covers the
inventory of systems and the determination as to where potential problems may
exist. If a system can not be determined to be either compliant or not date
sensitive, it is deemed non-compliant and scheduled for inclusion in the
remediation/testing phases. The remediation phase is for the correction of any
year 2000 compliance issues through repair or replacement. It is estimated that
this phase is approximately 61% complete for IT systems and 3% complete for
non-IT systems. The testing phase, which is estimated to be approximately 65%
and 7% complete for IT and non-IT systems, respectively, is designed to provide
assurance that the remediation effort has been successful. Critical devices are
tested regardless of whether a manufacturer/vendor has indicated that the device
was year 2000 compliant. Columbia currently has in place general contingency
plans in the event that a computer system, facility or process fails; however,
Columbia is evaluating the need for special contingency plans in the event that
a year 2000 problem should arise in spite of Columbia's efforts to ensure year
2000 compliance. Where appropriate, specific year 2000 contingency plans will be
developed for those systems that are essential to Columbia's ongoing businesses.
Contingency plans involve having alternate suppliers, processes or personnel on
stand-by for essential processes. Columbia's planning for the year 2000
contingency phase for mission critical processes began on January 1, 1999.

For the overall year 2000 project, the assessment phase is complete. The
remediation phase is anticipated to be completed by the end of the first quarter
of 1999, with the testing phase anticipated to be completed by the end of the
second quarter of 1999. Any year 2000 specific contingency plans that may be
necessary are scheduled to be completed by the end of July 1999.

Another area of concern is Columbia's exposure from third parties that may not
be year 2000 compliant. Columbia is in the process of contacting third parties
with which it conducts business to obtain assurance that they will be year 2000
compliant, utilizing letters and, where appropriate, questionnaires. Columbia
has mailed letters to many of its significant vendors and service providers and
has verbally communicated with many strategic customers to determine whether or
not interfaces with such entities are vulnerable to year 2000 problems and
whether the products and services purchased from or by such entities are year
2000 compliant. Columbia has received responses from a large number of these
third parties with many of the companies providing written assurances that they
expect to address all of their significant year 2000 issues on a timely basis. A
follow-up mailing to significant vendors and service providers that did not
initially respond, or whose responses were deemed unsatisfactory by Columbia, is
currently underway.

The total estimated cost of assessing, testing and remediating Columbia's IT and
non-IT systems for year 2000 compliance, along with the cost of developing
contingency plans, is approximately $15.6 million. The bulk of Columbia's year
2000 project budget will be applied to the remediation and testing phases. The
estimated total cost of the year 2000 project represents management's
assessment, based on information currently available, scope of the project, work
already completed and estimated remaining work. The expenditures necessary to
become year 2000 compliant will be satisfied through Columbia's cash flow from
operations.

As part of its normal operations, Columbia continuously operates in a
safety-conscious, high-reliability environment and has numerous back-up systems
in place. As a result of the extensive planning that has been incorporated into
Columbia's current contingency plans and the year 2000 project, management
believes that the most reasonably likely worst case year 2000 scenario would
involve minor failures that were not detected and corrected during the

                                       20
<PAGE>   21
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

project. These failures should not be of the type that could result in the
disruption of services and will, in all likelihood, be corrected quickly.
However, the failure of Columbia or a key third party supplier to correct a
material year 2000 problem could result in an interruption in, or a failure of,
certain normal business activities or operations including Columbia's ability to
deliver energy. For such a failure to be material, numerous back-up systems or
processes would also have to fail. For example, an interruption in electric
service along Columbia's pipeline system could impact the operation of one or
more compressor stations or other field facilities and equipment. This impact,
if coupled with the failure of critical back-up systems and processes, could
materially and adversely affect Columbia's operations, liquidity and financial
condition. Due to the general uncertainty inherent in the year 2000 issue, due
in part to the uncertainty of the year 2000 readiness of third party suppliers
and customers, Columbia is unable to determine at this time whether the
consequences of any likely year 2000 failures will have a material impact on
Columbia's operations, liquidity or financial condition.

Common Stock Prices and Dividends*

<TABLE>
<CAPTION>
                                                         Market Price                               
                                                                                                             Quarterly
Quarter Ended                  High                        Low                        Close                Dividends Paid
- --------------------------------------------------------------------------------------------------------------------------
<S>                            <C>                         <C>                        <C>                  <C> 
                               $                           $                          $                        $

1998
December 31                     60  3/4                     54  1/4                    57  3/4                  .20
September 30                    60  3/8                     47  1/2                    58  5/8                  .20
June 30                         57 11/12                    50  1/3                    55  5/8                  .20
March 31                        52 17/24                    47  1/3                    51  5/6                  .17

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

1997
December 31                     52  5/12                    46  1/3                    52  3/8                  .17
September 30                    48  1/6                     43 11/24                    46  2/3                 .17
June 30                         44 11/12                    37  1/3                    43  1/2                  .16
March 31                        43 11/12                    38  5/12                   38  7/12                 .10

- --------------------------------------------------------------------------------------------------------------------------
</TABLE>

* Amounts have been restated to reflect a three-for-two common stock split, in
the form of a stock dividend, effective June 15, 1998.

                                       21
<PAGE>   22
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)


                       TRANSMISSION AND STORAGE OPERATIONS

Columbia's transmission and storage segment consists of Columbia Transmission,
Columbia Gulf Transmission Company (Columbia Gulf) and Columbia Pipeline
Company. Together they operate a 16,658 mile pipeline network extending from
offshore in the Gulf of Mexico to Lake Erie, New York and the eastern seaboard
serving 15 northeastern, midatlantic, midwestern and southern states, as well as
the District of Columbia. In addition, Columbia Transmission operates one of the
nation's largest underground natural gas storage systems.

Proposed Millennium Pipeline Project
The proposed Millennium Pipeline Project (Millennium Project), in which Columbia
Transmission is participating and will serve as developer and operator, will
transport western gas supplies to northeast and midatlantic markets. The
442-mile pipeline will connect to TransCanada Pipe Lines Ltd. at a new Lake Erie
export point and transport approximately 700,000 Mcf per day to eastern markets.
Ten shippers have signed agreements for the available capacity. A filing with
the Federal Energy Regulatory Commission (FERC), requesting approval of the
Millennium Project, was made on December 22, 1997. This filing began the
extensive review process, including opportunities for public review,
communication and comment. The Millennium Project sponsors have announced that
the proposed in-service date is expected to be November 1, 2000.

The current sponsors of the proposed Millennium Project are Columbia
Transmission, Westcoast Energy, Inc., TransCanada Pipe Lines Ltd., and MCN
Energy Group, Inc.

Market Expansion Project
Columbia Transmission continued construction of its Market Expansion project
that expands its pipeline and storage system to meet increased customer demands.
The second phase of storage service began in April 1998, and transportation
service began in November 1998. Upon completion in 1999, the expansion will add
approximately 500,000 Mcf per day of firm service to 23 customers.

The New York State Electric & Gas Corporation (NYSEG) filed an appeal with the
U. S. Court of Appeals for the District of Columbia Circuit, primarily to
challenge the FERC's approval of rolled-in pricing for the Market Expansion
project service levels. All briefing is complete with oral arguments being the
next step. NYSEG has not requested a stay of Columbia Transmission's FERC
certificate order. Accordingly, construction is proceeding.

Proposed East Lateral Expansion and SunStar Pipeline Projects
Columbia Gulf announced plans in September 1998 to consider an expansion of its
onshore East Lateral system at Grand Isle, Louisiana. The expansion of the East
Lateral system would provide additional capacity to shippers from Grand Isle by
adding approximately 600,000 Mcf per day of incremental firm transportation
capacity. This will be accomplished by adding new facilities and expanding
existing facilities. The proposed SunStar Pipeline Project, in which Columbia
Gulf is participating and will serve as the developer and operator, would
transport gas from the deep water areas of the Gulf of Mexico to Columbia Gulf's
onshore lateral at Grand Isle. This offshore pipeline project of approximately
56 miles would have capacity of 660,000 Mcf per day and is complementary to the
expansion of the East Lateral system facilities, mentioned above.

Columbia Gulf conducted open seasons in the fall of 1998 to obtain binding
commitments from interested parties for the additional capacity resulting from
the East Lateral expansion and the SunStar Pipeline Project. Columbia Gulf is
currently in the process of evaluating the bids.

Competition and the Effect of LDC Unbundling Services
Columbia's transmission and storage subsidiaries compete with other interstate
pipelines for the transportation and storage of natural gas. Since the issuance
of FERC Order No. 636, various states throughout Columbia Transmission's service
area have initiated proceedings dealing with open access and unbundling of local
distribution companies' (LDC) services. Among other things, unbundling involves
providing all LDC customers with the choice of what entity will serve as
transporter as well as merchant supplier. While the scope and timing of these
various unbundling initiatives varies from state to state, retail choice
programs are being extended to increasing numbers of LDC customers throughout
Columbia Transmission's market area.

Among the issues being addressed in the state unbundling proceedings is the
treatment of the pipeline transmission and storage agreements which have
underpinned the traditional LDC merchant function. In the case of Columbia
Transmission and Columbia Gulf, contracts covering the majority of their firm
transportation and storage quantities

                                       22
<PAGE>   23
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

with LDCs have primary terms that extend to October 31, 2004. Management fully
expects that the LDCs, or those entities to which pipeline capacity may be
assigned as a result of the LDC unbundling process, will continue to fulfill
their obligations under these contracts. However, in view of the changing market
and regulatory environment, Columbia's transmission companies have commenced the
process of discussing long-term transportation and storage service needs with
their firm customers. Those discussions could result in the restructuring of
some of these contracts on mutually agreeable terms prior to 2004.

Regulatory Matters
                         Columbia Gulf's Rate Settlement
On April 29, 1998, the FERC approved a settlement of Columbia Gulf's general
rate case that was filed in October 1996. The active parties in the proceeding
unanimously agreed to the terms of the settlement. The approval of the
settlement, which became final May 29, 1998, did not have a material impact on
Columbia's consolidated financial results.

                   Columbia Gulf Mainline Capacity Proceeding
In 1993, the FERC directed Columbia Gulf to show cause as to why it had not
sought FERC abandonment authorization to reduce capacity on its mainline
facility. Since that time Columbia Gulf has responded to various information
requests from the FERC. In an August 8, 1997 order, the FERC approved a
stipulation and consent agreement between Columbia Gulf and FERC's enforcement
staff requiring Columbia Gulf to conduct a 30-day open season on additional firm
mainline capacity up to its certificated design. Although certain of Columbia
Gulf's customers challenged the terms of the settlement, Columbia Gulf concluded
the open season on December 15, 1997, which resulted in requests for capacity
that exceeded the capacity specified in Columbia Gulf's FERC certificate. On
December 24, 1998, the FERC issued an order rejecting all substantial challenges
and reaffirmed the settlement. On January 25, 1999, a petition for clarification
or rehearing and a separate petition for rehearing of the FERC's December 24,
1998 order were filed in this proceeding. On February 19, 1999, the FERC issued
a tolling order giving itself additional time to act on the January 25, 1999
petitions. In late February 1999, five parties appealed the December 24, 1998
and August 8, 1997 FERC orders to the Court of Appeals for the District of
Columbia.

                                  Mainline '99
Columbia Gulf filed an application with the FERC on June 5, 1998, for authority
to increase the maximum certificated capacity of its mainline facilities. The
expansion project, referred to as Mainline '99, will increase Columbia Gulf's
certificated capacity to nearly 2.2 Bcf/day, by replacing certain compressor
units and increasing the horsepower capacity of other compressor stations.
Various shippers contracted for the additional service through an open bidding
process held in late 1997 and early 1998. Subject to regulatory approval,
construction relating to the compressor replacements is scheduled to begin in
the first quarter of 1999. The proposed in-service date for the Mainline '99
project is December 1, 1999. At its February 10, 1999, meeting the FERC adopted
an order approving Columbia Gulf's June 5, 1998 filing.

                Columbia Transmission's Phase II Rate Proceeding
Columbia Transmission's rate case settlement, approved by the FERC in April
1997, provided for a hearing to address environmental cost recovery that was
excluded from the settlement. The procedural schedule established by the
presiding Administrative Law Judge provided for a hearing to commence in the
fall of 1998. However, at the request of Columbia Transmission and other active
parties, the schedule was suspended in May 1998, in order to afford the parties
an opportunity to pursue settlement discussions. As a result of these
discussions, the active parties reached an agreement in principle on the overall
components of an environmental settlement. The comprehensive agreement in
principle includes such major components as Columbia Transmission's total
allowed recovery of environmental remediation program costs and the disposition
of any proceeds received by Columbia Transmission from insurance carriers and
others. At this time, the agreement is either supported or not opposed by all
but two parties. Columbia Transmission anticipates filing a stipulation and
agreement with the FERC in the first quarter of 1999.

                Challenge to Columbia Transmission's Rate Design
Pursuant to a provision of Columbia Transmission's 1997 rate settlement, the
Public Service Commission of the State of New York (PSCNY) had the right to
initiate a hearing challenging the appropriateness of the Straight Fixed
Variable (SFV) rate design methodology authorized by the FERC for Columbia
Transmission. In a decision rendered in April 1998, the presiding Administrative
Law Judge granted a motion, filed jointly by several interested parties, to
dismiss a challenge made by PSCNY. The Judge found that the PSCNY failed to
demonstrate that continued use of the SFV rate design on Columbia Transmission's
system would be unjust or unreasonable. In May 1998, the PSCNY filed an appeal
of the Administrative Law Judge's decision and on October 6, 1998, the FERC
affirmed the Judge's decision.

                                       23
<PAGE>   24
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

The PSCNY filed a limited request for rehearing of the FERC's decision on
November 5, 1998. In December 1998, the FERC issued an order denying PSCNY's
request for rehearing.

                              Discussions with FERC
The transmission and storage subsidiaries are in confidential and informal
discussions with the staff of the FERC concerning the scope of authorization for
certain past transactions under the relevant filed tariffs. The transmission and
storage subsidiaries have initiated these discussions with the FERC. Because
these discussions are in a very preliminary stage, management is unable to
reasonably estimate the amount that will have to be paid pursuant to
reimbursement or other remedies.

Sale of Gathering Facilities
During 1997, Columbia Transmission sold approximately 4,500 miles of its
gathering lines of which 2,700 miles were sold to Columbia Resources.
Approximately 750 miles of gathering facilities were sold to Columbia Resources
effective January 1999. There are approximately 800 miles of gathering lines
remaining to be sold.

In addition, Columbia Transmission has agreed to sell certain natural gas
pipeline facilities that consist of approximately 341 miles of pipeline,
together with property and associated facilities, located in New York and
Pennsylvania. The sale of these facilities was approved by the FERC in an order
issued on November 4, 1998. Certain parties requested rehearing of the FERC's
decision. At its regularly scheduled meeting on February 10, 1999, the FERC
approved a draft order denying rehearing. The FERC's action on rehearing will
allow the sale to go forward as planned. The facilities are not directly
connected to Columbia Transmission's mainline system and are no longer needed by
Columbia Transmission in connection with providing services to its customers.
The sale of these assets would not have a material impact on Columbia's
consolidated financial results.

Additional Storage Base Gas Sales
As provided in Columbia Transmission's recent rate settlement, Columbia
Transmission is allowed to retain approximately 95% of the first $60 million
pre-tax gain from any base gas sales and to share equally with customers any
gain after that level. Columbia Transmission has agreements to sell
approximately 6.9 Bcf of base gas volumes in the first quarter of 1999 pursuant
to the settlement agreement.

Capital Expenditure Program
The transmission and storage segment's net capital expenditure program was $204
million in 1998 and is projected to be $237 million in 1999. New business
initiatives totaled approximately $95 million in 1998 and are expected to be
$126 million in 1999. The remaining expenditures are for modernizing and
upgrading facilities.

Environmental Matters
Columbia's transmission subsidiaries have implemented programs to continually
review compliance with existing environmental standards. In addition,
transmission subsidiaries continue to review past operational activities and to
formulate remediation programs where necessary.

Columbia Transmission is currently conducting assessment, characterization and
remediation activities at specific sites under a 1995 Environmental Protection
Agency (EPA) Administrative Order by Consent (AOC). The program pursuant to the
AOC covers approximately 240 facilities, approximately 15,000 liquid removal
points, approximately 2,800 mercury measurement stations and about 3,700 storage
well locations. As of December 31, 1998, field characterization has been
performed at many of these sites, and site characterization reports and
remediation plans are being prepared for submission to EPA for approval.
Significant remediation has taken place only at mercury measurement stations.
Only those site investigation, characterization and remediation costs currently
known and determinable can be considered "probable and reasonably estimable"
under Statement of Financial Accounting Standards No. 5, "Accounting for
Contingencies" (SFAS No. 5). As costs become probable and reasonably estimable,
the associated reserves will be adjusted as appropriate. Columbia Transmission
is unable, at this time, to accurately estimate the time frame and potential
costs of the entire program. Management expects that as additional work is
performed and more facts become available, it will be able to develop a probable
and reasonable estimate for the entire program or a major portion thereof
consistent with U.S. Securities and Exchange Commission's Staff Accounting
Bulletin No. 92, SFAS No. 5, and American Institute of Certified Public
Accountants Statement of Position 96-1.

As a result of 1998 activities, Columbia Transmission recorded an additional
liability of $28.8 million. Actual expenditures of approximately $16 million
during 1998 charged to the liability resulted in a remaining liability of $138.2
million. Columbia Transmission's environmental cash expenditures are expected to
be approximately $18

                                       24
<PAGE>   25
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

million in 1999 and up to $20 million annually until the AOC is satisfied. These
expenditures will be charged against the previously recorded liability.
Consistent with Statement of Financial Accounting Standards No. 71, a regulatory
asset has been recorded to the extent environmental expenditures are expected to
be recovered through rates. Management does not believe that Columbia
Transmission's environmental expenditures will have a material adverse effect on
its operations, liquidity or financial position, based on known facts and
existing laws and regulations and the long time period over which expenditures
will be made.

In addition, predecessor companies of Columbia Transmission may have been
involved in the operation of manufactured gas plants. When such plants were
abandoned, material used and created in the process was sometimes buried at the
site. As of the date of this report, Columbia Transmission is unable to
determine if it will become liable for any characterization or remediation costs
at such sites.

Throughput
Columbia Transmission's throughput consists of transportation and storage
services for local distribution companies and other customers within its market
area. Throughput for Columbia Gulf reflects mainline transportation services
from Rayne, Louisiana, to Leach, Kentucky and short-haul transportation services
from the Gulf of Mexico to Rayne, Louisiana.

Throughput for the transmission and storage segment totaled 1,197.5 Bcf for
1998, a decrease of 104 Bcf from 1997 that was in turn down 76.6 Bcf from 1996.
The lower throughput in 1998 and 1997 was primarily due to warmer weather in
Columbia Transmission's operating territory that reduced demand for natural gas.

Columbia Transmission's market area transportation declined 84.8 Bcf to 947.8
Bcf during 1998, largely due to 18% warmer weather in its market area.
Transportation volumes for 1997 of 1,032.6 Bcf decreased 69.8 Bcf from 1996
primarily due to warmer weather in early 1997 and reduced requirements from
electric cogeneration facilities during the summer.

Mainline transportation for Columbia Gulf decreased 44.2 Bcf to 563.3 Bcf in
1998, reflecting the impact of warmer weather in Columbia Transmission's
operating territory. During 1997, mainline transportation was 26.2 Bcf lower
than 1996 due to warmer weather. In addition, mainline transportation volumes
were higher in 1996 due to Columbia Gulf's system being heavily used by
customers during the summer of that year to refill depleted gas storage
inventories.

Columbia Gulf's 1998 short-haul transportation of 231.2 Bcf decreased 21.2 Bcf
from the year earlier, largely due to the unusually warm weather. Short-haul
transportation of 252.4 Bcf in 1997 was down 14.1 Bcf from 1996 primarily due to
a decline in market demand in the area south of Rayne, Louisiana.

Variations in throughput have little effect on operating income because, as a
result of FERC Order No. 636, a significant portion of the transmission and
storage segment's fixed costs is being recovered through a monthly demand
charge.

Operating Revenues
Operating revenues of $838.7 million in 1998 were essentially unchanged from the
prior year. After adjusting for the recovery of upstream transportation costs
and certain other revenues that are fully offset in operating expense, operating
revenues in 1998 decreased $2.6 million. The effect of the sale of gathering
facilities and a lower cost-of-service level underlying Columbia Transmission's
rates in 1998 was only partially offset by increased revenues from
transportation and storage services due in part to Columbia Transmission's
Market Expansion project. The sale of storage base gas volumes that were part of
Columbia Transmission's overall 1997 rate case settlement improved revenues in
both 1998 and 1997.

Operating revenues increased $33.6 million to $838.6 million in 1997. After
adjusting for recovery items mentioned above, operating revenues increased $22.6
million over 1996. This increase was primarily due to recording $19.1 million of
revenues in the second quarter of 1997 for the sale of base gas volumes that
were part of Columbia Transmission's 1997 rate case settlement. Increased
transportation and storage services also contributed to the improvement.

Operating Income
Operating income for 1998 for the transmission and storage segment of $326.1
million, increased $67.8 million over 1997 due to a decline in operating
expense. Operation and maintenance expenses for 1998 declined $64.3 million

                                       25
<PAGE>   26
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

compared with 1997, primarily reflecting restructuring costs recorded in 1997
and the beneficial effect of those restructuring initiatives in 1998. Also
making 1997 operation and maintenance expense higher when compared to 1998 was a
$10.1 million reserve recorded in 1997 for the anticipated sale of certain
pipeline facilities.

Operating income for 1997 of $258.3 million, increased $52.1 million over the
previous year. This improvement reflected higher operating revenues, mentioned
above, and $18.5 million lower operating expenses due in part to lower
restructuring costs and savings achieved through the implementation of
restructuring initiatives.

     STATEMENTS OF OPERATING INCOME FROM TRANSMISSION AND STORAGE OPERATIONS
                                   (UNAUDITED)


<TABLE>
<CAPTION>
Year Ended December 31, (in millions)            1998                    1997                    1996
- ------------------------------------------------------------------------------------------------------
<S>                                           <C>                     <C>                     <C>
OPERATING REVENUES
   Transportation revenues                    $ 620.4                 $ 622.0                 $ 629.0
   Storage revenues                             186.0                   179.8                   159.5
   Other revenues                                32.3                    36.8                    16.5
- ------------------------------------------------------------------------------------------------------

Total Operating Revenues                        838.7                   838.6                   805.0
- ------------------------------------------------------------------------------------------------------

OPERATING EXPENSES
   Operation and maintenance                    358.9                   423.2                   440.1
   Depreciation                                 101.8                   104.3                   102.6
   Other taxes                                   51.9                    52.8                    56.1
- ------------------------------------------------------------------------------------------------------

Total Operating Expenses                        512.6                   580.3                   598.8
- ------------------------------------------------------------------------------------------------------

OPERATING INCOME                              $ 326.1                 $ 258.3                 $ 206.2
- ------------------------------------------------------------------------------------------------------
</TABLE>


                  TRANSMISSION AND STORAGE OPERATING HIGHLIGHTS


<TABLE>
<CAPTION>
                                                 1998        1997         1996         1995         1994
- ---------------------------------------------------------------------------------------------------------
<S>                                           <C>         <C>          <C>          <C>          <C>
CAPITAL EXPENDITURES ($ in millions)            204.0       244.9        142.7        169.1        179.1

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

THROUGHPUT (Bcf)
Transportation
   Columbia Transmission
      Market area                               947.8     1,032.6      1,102.4      1,106.1      1,038.6
   Columbia Gulf
      Mainline                                  563.3       607.5        633.7        605.0        590.3
      Short-haul                                231.2       252.4        266.5        221.4        225.4
      Intrasegment eliminations                (544.8)     (591.0)      (624.5)      (596.3)      (583.2)

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

Total Transportation                          1,197.5     1,301.5      1,378.1      1,336.2      1,271.1
Sales                                               -           -            -            -          0.9

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

TOTAL THROUGHPUT                              1,197.5     1,301.5      1,378.1      1,336.2      1,272.0

- ---------------------------------------------------------------------------------------------------------
</TABLE>

                                       26
<PAGE>   27
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)


                             DISTRIBUTION OPERATIONS

Columbia's five distribution subsidiaries (Distribution) provide natural gas
service to approximately 2 million residential, commercial and industrial
customers in Ohio, Pennsylvania, Virginia, Kentucky and Maryland.

Market Conditions
Weather in the market area served by Distribution during 1998 was the warmest on
record. It was 17% warmer than normal and 19% warmer than 1997. As a result,
there was nearly a 50 Bcf decrease in weather-sensitive deliveries compared to
1997. The settlement of a 10-month labor strike at a major customer late in 1997
partially offset the decline in deliveries brought about by the record warm
weather in 1998.

Competition
Distribution competes with investor-owned, municipal, and cooperative electric
utilities throughout its five-state service area, and to a lesser extent with
propane and fuel oil suppliers. Electric competition is generally strongest in
the residential and commercial markets of Kentucky, southern Ohio and
southwestern Pennsylvania where rates are driven by low-cost coal-fired
generation. The northern Ohio and Pittsburgh areas have less competitive
electric rates, due to the use of higher-cost nuclear-generated power.
Distribution continues to be a strong competitor in the energy market for new
homes as a result of a strong customer preference for natural gas. With the
addition of residential and small commercial customer choice programs, natural
gas is now more price-competitive with alternate fuels.

Approximately 40% of Distribution's industrial and commercial throughput, or 140
Bcf, is susceptible to bypass, because these customers are located close to
multiple natural gas pipelines and local gas distribution companies. As a result
of Distribution's competitive strategies, substantial inroads by other natural
gas competitors have been avoided to date. As a result, the estimated throughput
exposure to bypass has been reduced to approximately 48 Bcf, representing about
$12 million in annual net revenue.

Regulatory Matters
Columbia Gas of Virginia, Inc. (Columbia of Virginia) filed a rate case with the
Virginia State Corporation Commission (VSCC) in May 1998, requesting a $13.8
million increase in annual revenue. Of the requested increase, $8.5 million has
been collected through interim rates in effect since October 1997, subject to
refund, as a result of Columbia of Virginia's 1997 rate case filing. In February
1999, the VSCC in the 1997 rate case issued an order authorizing an increase in
annual revenue of $4.6 million. Rates reflecting the requested additional
increase in annual revenue of $5.3 million in the 1998 rate case filing went
into effect, also subject to refund, in October 1998. The higher revenue is
needed to recover costs related to plant additions including those required to
replace aging facilities and to recover normal increases in operating expenses.
Resolution of these proceedings will not have a material impact on Columbia's
consolidated financial results.

In February 1998, the Maryland Public Service Commission (MPSC) approved the
agreement reached by Columbia Gas of Maryland, Inc. (Columbia of Maryland) with
the MPSC staff and the Maryland People's Counsel. The People's Counsel had
sought an annual revenue reduction of $1.6 million, and Columbia of Maryland had
requested an annual revenue increase of $1.2 million. The agreement provided for
an annual revenue increase of $200,000. The new rates went into effect in March
1998.

In July 1998, Columbia Gas of Kentucky, Inc. (Columbia of Kentucky) received
approval from the Kentucky Public Service Commission (KPSC) to extend its pilot
gas cost incentive program for another year until July 31, 1999. The off-system
sales program has been in effect on a pilot basis since August 1, 1996. Columbia
of Kentucky must file a petition with the KPSC by July 1, 1999, to continue the
program beyond August 1, 1999.

Distribution continues to pursue initiatives that give retail customers the
opportunity to purchase natural gas directly from marketers and to use
Distribution's facilities for transportation services. These opportunities are
being pursued through regulatory initiatives in all of its jurisdictions, which
resulted in transportation programs being initiated in four of its five service
areas. Once fully implemented, these programs would reduce Distribution's
merchant function and provide all customer classes with the opportunity to
obtain gas supplies from alternative merchants. As these programs expand to all
customers, regulations will have to be implemented to provide for the recovery
of capacity costs and other costs incurred by a utility serving as the supplier
of last resort if the marketing company cannot supply the gas. The state
commissions in Distribution's five jurisdictions are at various stages in
addressing these issues and other transition considerations. Distribution is
currently recovering the costs resulting from the

                                       27
<PAGE>   28
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

unbundling of its services and believes that most of such future costs and costs
resulting from being the supplier of last resort will be recovered. In addition
to the supplier of last resort issue, Columbia of Ohio will be at risk for up to
11% of the transition capacity costs.

In June 1998, Columbia of Ohio received approval from the Public Utilities
Commission of Ohio (PUCO) to extend its Customer CHOICE(SM) program to all of
its nearly 1.3 million customers. The PUCO approval to expand and continue the
program was based on Columbia's successful program in three northwestern Ohio
counties. There are now over 357,000 customers participating, including
approximately 320,000 residential customers. Of 44 marketers approved for
participation, 26 are currently active.

Columbia Gas of Pennsylvania, Inc. (Columbia of Pennsylvania) received
permission from the Pennsylvania Public Utility Commission (PPUC) in July 1998
to expand its Customer CHOICE(SM) program into five additional counties.
Customers began shopping for a new supplier in August 1998 for gas deliveries
that started in November 1998. Programs have been in operation in Allegheny and
Washington counties and the approved expansion means that over two-thirds of
Columbia of Pennsylvania's 386,000 customer base would be eligible to
participate in the Customer CHOICE(SM) program. There are now over 58,000
customers and nine marketers participating in the program. Meanwhile, Columbia
of Pennsylvania continues to push for a legislative proposal that would set the
terms for natural gas retail competition statewide.

Columbia of Virginia's two-year pilot transportation program for residential and
small commercial customers began December 1, 1997 and is open to approximately
27,000 customers in the Gainesville market area of Northern Virginia. There are
now over 6,300 customers and six marketers participating in the program.
Columbia of Virginia is supporting legislation that would permit it to offer all
of its 178,000 customers the opportunity to choose their natural gas supplier.

In August 1998, the MPSC approved a two-year continuation of Columbia of
Maryland's Customer CHOICE(SM) program for all of its customers. Introduced in
1996, the program allows more than 30,000 of Columbia of Maryland's customers to
consider a natural gas supplier other than Columbia of Maryland. There are
approximately 3,000 customers and four marketers participating in the program.

Columbia of Kentucky plans to make a filing with the KPSC in the spring of 1999
seeking approval to initiate a residential and small commercial transportation
program. Under the terms of the proposed filing, all of Columbia of Kentucky's
140,000 customers would be eligible to choose a new supplier for gas to be
delivered commencing in November 1999.

Voluntary Severance Plans
In January 1999, Columbia of Pennsylvania announced a Voluntary Severance
Program (VSP) available to all of its nearly 700 employees in the operations
department. The program is an effort to bring staffing levels into balance with
anticipated work assignments. Stagnant market growth, new technologies, a more
modern pipeline system and a more efficient management system for assigning work
is permitting Columbia of Pennsylvania to meet its operations obligations with
fewer employees. When combining the VSP with other workforce reduction measures,
Columbia of Pennsylvania may be able to reduce staffing by approximately 50
employees. These initiatives are anticipated to result in a charge to operating
expense in the first half of 1999.

Capital Expenditure Program
Distribution's 1998 capital expenditures were approximately $151.9 million, a
decrease of $7.6 million from 1997. In addition to maintaining and upgrading
facilities to assure safe, reliable and efficient operation, 1998 expenditures
included $60.9 million for extending service to new areas and $72.1 million for
replacement and betterment projects. The estimated 1999 capital expenditure
program amounts to approximately $152 million, including $59 million for new
business and development, $67 million for replacement and betterment projects
with the remainder primarily for support services.

Gas Supply
Distribution's gas supply portfolio, with its large storage component, has the
reliability and flexibility to accommodate the impact of weather variations on
traditional customer demand, as well as to provide opportunities to increase
revenues through off-system sales and other incentive programs. Off-system sales
are sales or other transactions conducted outside of Distribution's traditional
market. For 1998, Distribution had off-system sales of 62.9 Bcf. This was an
increase of 17.5 Bcf from 1997 due in part to the mild weather throughout the
year that allowed Distribution to market its storage volumes. Columbia of Ohio,
Columbia of Pennsylvania, Columbia of

                                       28
<PAGE>   29
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

Maryland and Columbia of Kentucky have incentive programs in place that have
been approved by their respective regulatory commissions that provide for the
sharing of the proceeds from off-system sales with customers. For 1998, these
programs resulted in pre-tax income for Distribution of $24 million, a decrease
of $2.1 million from 1997. Columbia of Ohio's 1996 rate settlement permitted the
retention of up to $51 million from off-system sales over three years subject to
an earnings limitation.

Proceeds from releasing unused pipeline capacity totaled $31.3 million for 1998,
up $11.8 million from 1997. Distribution can retain a portion of the proceeds
that exceeds established capacity release incentive benchmarks. All other
proceeds are recorded as a reduction to gas costs and the benefit is passed
through to customers. In 1998, Columbia of Ohio and Columbia of Maryland were
able to retain capacity release proceeds totaling $1.1 million. As residential
and small commercial transportation programs develop into widespread practice
and marketers take assignment of the LDC's pipeline capacity contracts, earnings
from these non-traditional services may decline.

Environmental Matters
Distribution's primary environmental issues relate to 15 former manufactured gas
plant sites. Investigations or remedial activities are currently underway at
seven sites and have been completed at one site. Additional site investigations
may be required at some of the remaining sites. To the extent Distribution's
site investigations have been conducted, remediation plans developed and any
responsibility for remediation action established, the appropriate liabilities
have been recorded. Regulatory assets have also been recorded for a majority of
these costs as rate recovery has been authorized or is anticipated.

Throughput 
Distribution's 1998 total volumes sold and transported of 558.2 Bcf decreased
13.9 Bcf from 1997 due to the record warm weather in 1998. Increased off-system
sales, the return to full production of the major customer idled by a 10-month
strike in 1997, increased industrial transportation volumes and customer growth
partially offset the adverse impact on sales of unusually warm weather in 1998.

In 1997, Distribution's total volumes sold and transported of 572.1 Bcf
increased 7.1 Bcf from 1996, as increased transportation and off-system sales
offset the adverse impact of warmer weather, a reduction in customer usage and
the impact of the strike at the major customer. Transportation volumes were up
by 10.1 Bcf in 1997 compared to 1996, reflecting higher demand for power
generation and competitive natural gas prices.

Net Revenue
In 1998, net revenue was $847 million, down $51.1 million from 1997. This
decrease primarily reflects the record warm weather, which reduced net revenue
approximately $76 million from 1997. The decrease was only partially offset by
the beneficial impact of Columbia of Ohio's 1997 regulatory settlement.

Net revenue for 1997 of $898.1 million was down $8.6 million from 1996, due to
the warmer weather that reduced net revenue by $20 million. This decrease
attributable to the warmer weather was partially offset by an increase in
revenue from Columbia of Ohio's 1997 rate settlement, together with income for
certain gas management activities that Columbia of Ohio retained under the terms
of its 1996 rate settlement.

Operating Income
Operating income for 1998 of $225.8 million increased by $1.6 million from 1997,
as the decline in net revenue was more than offset by a $52.7 million decrease
in operating expenses. Operation and maintenance expense for 1998 decreased
$54.3 million to $386.7 million, primarily reflecting a reduction in
postretirement benefit costs and the ongoing beneficial impact of the
restructuring initiatives implemented in 1997. Other taxes decreased $2.4
million from 1997, primarily due to lower payroll taxes and depreciation expense
increased by $4 million due in part to plant additions.

In 1997, operating income decreased by $1.8 million from 1996 to $224.2 million
as the decrease in net revenue was only partly offset by a $6.8 million decline
in operating expenses. The decrease in operating expenses was primarily due to a
reduced level of restructuring costs recorded in 1997 and the implementation
during 1996 and 1997 of cost conservation measures and operating efficiencies.

                                       29
<PAGE>   30
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

     STATEMENTS OF OPERATING INCOME FROM DISTRIBUTION OPERATIONS (UNAUDITED)


<TABLE>
<CAPTION>
Year Ended December 31, (in millions)                 1998                       1997                     1996
- ---------------------------------------------------------------------------------------------------------------
<S>                                              <C>                        <C>                      <C>
NET REVENUES
   Sales revenues                                $ 1,686.3                  $ 2,153.1                $ 2,007.9
   Less: Cost of gas sold                          1,005.4                    1,385.6                  1,206.4
- ---------------------------------------------------------------------------------------------------------------

   Net Sales Revenues                                680.9                      767.5                    801.5
- ---------------------------------------------------------------------------------------------------------------

   Transportation revenues                           183.2                      143.2                    119.8
   Less: Associated gas costs                         17.1                       12.6                     14.6
- ---------------------------------------------------------------------------------------------------------------

   Net Transportation Revenues                       166.1                      130.6                    105.2
- ---------------------------------------------------------------------------------------------------------------

Net Revenues                                         847.0                      898.1                    906.7
- ---------------------------------------------------------------------------------------------------------------

OPERATING EXPENSES
   Operation and maintenance                         386.7                      441.0                    463.0
   Depreciation                                       82.2                       78.2                     74.4
   Other taxes                                       152.3                      154.7                    143.3
- ---------------------------------------------------------------------------------------------------------------

Total Operating Expenses                             621.2                      673.9                    680.7
- ---------------------------------------------------------------------------------------------------------------
  
OPERATING INCOME                                 $   225.8                  $   224.2                $   226.0
- ---------------------------------------------------------------------------------------------------------------
</TABLE>

                                       30
<PAGE>   31
ITEM 7.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS (continued)

                        DISTRIBUTION OPERATING HIGHLIGHTS


<TABLE>
<CAPTION>
                                                    1998              1997               1996             1995              1994
- ---------------------------------------------------------------------------------------------------------------------------------
<S>                                              <C>               <C>                <C>              <C>               <C>
CAPITAL EXPENDITURES ($ in millions)               151.9             159.5              148.4            151.8             151.4
- ---------------------------------------------------------------------------------------------------------------------------------

THROUGHPUT (Bcf)
Sales
   Residential                                     149.1             190.9              209.4            196.6             189.7
   Commercial                                       54.1              72.7               85.7             79.5              80.8
   Industrial and Other                              4.4               4.2               10.3              7.1               9.7
- ---------------------------------------------------------------------------------------------------------------------------------

Total Sales                                        207.6             267.8              305.4            283.2             280.2
Transportation                                     287.7             258.9              248.8            255.9             232.5
- ---------------------------------------------------------------------------------------------------------------------------------

Total Throughput                                   495.3             526.7              554.2            539.1             512.7
Off-System Sales                                    62.9              45.4               10.8              7.5               0.3
- ---------------------------------------------------------------------------------------------------------------------------------

Total Sold and Transported                         558.2             572.1              565.0            546.6             513.0
- ---------------------------------------------------------------------------------------------------------------------------------

SOURCES OF GAS FOR THROUGHPUT (Bcf)
Sources of Gas Sold
   Spot market*                                    223.5             295.0              298.7            210.4             235.3
   Producers                                        17.7              35.7               47.9             70.9              67.5
   Storage withdrawals (injections)                 12.4               4.0              (20.8)            23.6             (14.0)
   Company use and other                            16.9             (21.5)              (9.6)           (14.2)             (8.3)
- ---------------------------------------------------------------------------------------------------------------------------------

Total Sources of Gas Sold                          270.5             313.2              316.2            290.7             280.5
Gas received for delivery to customers             287.7             258.9              248.8            255.9             232.5
- ---------------------------------------------------------------------------------------------------------------------------------

Total Sources                                      558.2             572.1              565.0            546.6             513.0
- ---------------------------------------------------------------------------------------------------------------------------------

CUSTOMERS
Sales
   Residential                                 1,612,124         1,769,647          1,815,269        1,794,800         1,764,968
   Commercial                                    148,529           168,413            173,689          172,114           167,067
   Industrial and Other                            2,295             2,340              2,285            2,265             2,312
- ---------------------------------------------------------------------------------------------------------------------------------

Total Sales Customers                          1,762,948         1,940,400          1,991,243        1,969,179         1,934,347
Transportation                                   298,107            93,923             12,804            6,789             6,520
- ---------------------------------------------------------------------------------------------------------------------------------

Total Customers                                2,061,055         2,034,323          2,004,047        1,975,968         1,940,867
- ---------------------------------------------------------------------------------------------------------------------------------

DEGREE DAYS                                        4,635             5,736              5,975            5,692             5,530
- ---------------------------------------------------------------------------------------------------------------------------------
</TABLE>

* Reflects volumes under purchase contracts of less than one year.

                                       31
<PAGE>   32
ITEM 8.   FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


                      EXPLORATION AND PRODUCTION OPERATIONS

Columbia's exploration and production subsidiary, Columbia Resources, is one of
the largest independent natural gas and oil producers in the Appalachian Basin
and also has production operations in Canada. Columbia Resources produces over
40 Bcf equivalents (Bcfe) of natural gas and oil annually, owns and operates
7,300 wells, and has net proven reserve holdings of 801.5 Bcfe. Columbia
Resources also owns and operates approximately 4,500 miles of gathering
pipelines.

Columbia Resources seeks to achieve asset and profitable growth through
acquisitions, expanded drilling activities and divestiture of under-performing
assets. During 1998, Columbia Resources entered into agreements in Ontario
Province, Canada that provide Columbia Resources an expanded undeveloped acreage
base. Columbia Resources' reserve base and production levels have also been
expanded through the successful drilling and completion of 157 gross wells
during 1998. Based on the total of 197 gross wells drilled and completed, the
1998 success rate was 80%. In January 1999, Columbia Resources also completed
its acquisition of gathering pipeline facilities from Columbia Transmission with
the purchase of an additional 750 miles of pipeline in northern West Virginia.

Capital Expenditure Program 
Columbia Resources' 1998 capital expenditures of $75.7 million primarily reflect
investment in drilling and acquisitions. The 1999 capital expenditure program is
estimated at $104 million and provides for the drilling of 230 additional wells.
During 1999, Columbia Resources expects to continue efforts to expand and
enlarge the definition of its core Appalachian basin properties, as well as its
eastern Canadian properties, through development drilling, exploration projects
and pipeline projects. Columbia Resources may participate, through joint venture
agreements, in investment opportunities in other basins in the eastern United
States.

Natural Gas Prices
In early 1998, the industry began to experience a deterioration of prices as a
result of last winter being one of the warmest winters in recent history.
Surplus storage levels throughout the year, due in part to the record-breaking
warm temperatures, contributed to the continuation of low gas and oil prices.
Management believes that Columbia Resources is well positioned to take advantage
of opportunities in this low-price environment with per unit operating costs
among the lowest compared to its competitors.

In an effort to help manage the continued uncertainty of gas prices and to
stabilize earnings, Columbia Resources hedged a portion of its 1998 and 1999 gas
production that was subject to price volatility through a gas marketing
affiliate. The gas marketing affiliate in turn, as part of its normal course of
business, hedged these positions in the marketplace. In that manner, Columbia
Resources secured an average gas price of $2.91 per Mcf on 77% of 1998 at-risk
production resulting in a 1998 revenue increase of $11 million. Columbia
Resources has entered into agreements securing an average 1999 price of $2.79 on
28% of 1999 at-risk production. This position for 1999 includes the hedging of
certain risks associated with both the commodity and the Appalachia basis, which
generally represents transportation costs to bring gas from the Southwest to the
Appalachia area.

Production 
Gas production of 39.1 Bcf in 1998 increased 4.4 Bcf over 1997, primarily due to
the acquisition of Alamco in mid-1997 and new production brought online in 1998.
From 1996 to 1997, gas production increased by 3% reflecting the Alamco
acquisition together with well shut-ins in 1996 that limited production in that
year.

Oil and liquids production in 1998 increased by 2% from 1997 to 214,000 barrels.
The increase primarily reflects new well completions coming online. In 1997,
production was down 25% from 1996 largely due to the sale of a production field
in December 1996.

Operating Revenues
Operating revenues for 1998 were $127.5 million, an increase of $14.2 million
over 1997, primarily reflecting higher revenues generated from hedging
activities and the gas production increase, both of which were discussed above.
Columbia Resources' average gas sales price for 1998 was $2.91 per Mcf, an
increase of 11% from 1997. The strong natural gas prices reflect the benefit of
hedging a portion of 1998 production in late 1997 when prices were significantly
higher. Operating revenues in 1997 were $113.3 million, an increase of $8.8
million from 1996, primarily due to a reclassification in the recording of
gathering activities.

                                       32
<PAGE>   33
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA

Operating Income

In 1998, operating income improved by $6.3 million to $37.2 million, primarily
due to higher operating revenues, which were partially offset by an increase of
$8.9 million in depreciation and depletion expense due to additional investments
in acquisitions and drilling. Operating income of $30.9 million in 1997 improved
by $900,000 from 1996, as the improvement in operating revenues was mostly
offset by higher operation and maintenance expense due primarily to additional
costs associated with the Alamco acquisition.

    STATEMENTS OF OPERATING INCOME FROM EXPLORATION AND PRODUCTION OPERATIONS
                                   (UNAUDITED)

<TABLE>
<CAPTION>
Year Ended December 31, (in millions)             1998        1997        1996
- --------------------------------------------------------------------------------
<S>                                              <C>         <C>         <C>
OPERATING REVENUES
   Gas revenues                                  $ 113.9     $ 109.5     $  99.1
   Other revenues                                   13.6         3.8         5.4
- --------------------------------------------------------------------------------
Total Operating Revenues                           127.5       113.3       104.5
- --------------------------------------------------------------------------------
OPERATING EXPENSES
   Operation and maintenance                        44.6        45.7        37.0
   Depreciation and depletion                       36.5        27.6        28.8
   Other taxes                                       9.2         9.1         8.7
- --------------------------------------------------------------------------------
Total Operating Expenses                            90.3        82.4        74.5
- --------------------------------------------------------------------------------
OPERATING INCOME                                 $  37.2     $  30.9     $  30.0
- --------------------------------------------------------------------------------
</TABLE>

                EXPLORATION AND PRODUCTION OPERATING HIGHLIGHTS

<TABLE>
<CAPTION>
                                       1998     1997     1996     1995*    1994*
- --------------------------------------------------------------------------------
<S>                                   <C>      <C>      <C>      <C>      <C>
CAPITAL EXPENDITURES ($ in millions)   75.7    158.7     12.1     86.8     101.6
- --------------------------------------------------------------------------------
PROVED RESERVES 
Gas (Bcf)                             790.5    800.5    644.5    599.5     683.8
Oil and Liquids (000 Bbls)            1,835    1,700      774    1,651    12,255
- --------------------------------------------------------------------------------
PRODUCTION
Gas (Bcf)                              39.1     34.7     33.6     65.4      66.7
Oil and Liquids (000 Bbls)              214      210      281    2,849     3,611
- --------------------------------------------------------------------------------
AVERAGE PRICES 
Gas ($ per Mcf)**                      2.91     2.63     2.84     1.96      2.18
Oil and Liquids ($ per barrel)        12.76    17.99    19.07    16.17     15.09
- --------------------------------------------------------------------------------
</TABLE>

*  Include operating results from Columbia Gas Development Corporation, which
   was sold effective December 31, 1995. 
** Includes the effect of hedging activities as discussed in Note 1(G) of Notes
   to Consolidated Financial Statements.




                                       33
<PAGE>   34
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


                              MARKETING OPERATIONS

Columbia's wholesale and retail nonregulated natural gas and electric power
marketing operations are conducted by Columbia's wholly-owned subsidiary,
Columbia Energy Services Corporation (Columbia Energy Services). These
operations provide integrated energy-related products and services to wholesale,
industrial and commercial, and residential customers. Columbia Energy Services
can be categorized into three business lines: wholesale energy operations and
services, retail products and services, and online energy services through its
subsidiary, Energy.com Corporation (Energy.com). The wholesale business line
provides products and services to wholesale customers nationwide, including gas
and electricity supply, fuel management and transportation-related services,
management and optimization of energy-related assets, energy commodity sales and
services, risk management products and financial services. The retail business
line provides energy-related products and services to a diverse customer base
(industrial, commercial and residential). These products and services include
gas and electricity supply, energy management, software and other services.
Energy.com focuses on providing an internet commerce channel for energy
companies to sell to all retail customers.

The marketing operations expanded dramatically during 1998; however, this rapid
growth strained Columbia Energy Services' infrastructure and highlighted areas
that need improvement. Columbia Energy Services has been addressing the
administrative requirements related to the significantly increased trading
volumes and continues to implement new accounting systems and procedures that
are necessary to support this growth. As part of this process, certain financial
records have been identified that do not appear to have adequate third party
documentation or represent reconciliation differences between new subsidiary
ledger systems and other financial records. As a result of this analysis, a
$16.3 million pre-tax reserve was recorded in the fourth quarter of 1998.
Management believes that this reserve is adequate based on information currently
available.

In addition, during the fourth quarter of 1998, certain unusual trading
activity, which when combined with all other gas positions, caused a $6.5
million net decrease to gross margin. Management has taken corrective action
designed to prevent similar incidents from recurring. The continuing
effectiveness of such action will be monitored.

Wholesale Energy Activity

Wholesale activity primarily consists of gas trading and marketing, and electric
power trading and marketing, both of which have grown significantly in 1998.
This growth reflects an increased presence in southeast and midwest markets, as
well as an expanded portfolio of storage and transportation assets. Sales growth
has occurred through increased trading, aggressive management of LDC supply,
transportation and storage services, and through Columbia Energy Services'
participation in retail markets. These activities have expanded Columbia Energy
Services' overall wholesale trading capabilities.

During 1998, Columbia Energy Services invested significantly in its wholesale
risk management infrastructure, and related financial products and services.
Consequently, a number of transactions have been added to its overall trading
and marketing portfolio. For example, during 1998, Columbia Energy Services
entered into ten-year natural gas supply contracts with two separate municipal
gas authorities that together total 82 Bcf of natural gas. As part of the
agreements, the municipal gas authorities made advance payments to Columbia
Energy Services in 1998 totaling $137.5 million for future deliveries.

In mid-1998, Columbia Energy Services signed a long-term energy management
contract for a 365-megawatt combined-cycle, natural gas-fired generation
facility in Hopewell, Virginia. Columbia Energy Services began providing the
facility with natural gas in June 1998. This facility has a baseload volume of
approximately 5,000 million British thermal units (MMBtu) daily for steam
generation and a daily peak demand volume of up to 75,000 MMBtu for electric
generation to be sold in Virginia. In addition to supplying natural gas,
Columbia Energy Services is managing the facility's fuel oil reserve tanks.

In addition to natural gas commodity trading and marketing activities,
Columbia Energy Services entered the electricity trading business in December
1997 and has expanded its trading and scheduling operations in northeastern,
midwestern, southwestern, and western United States. Over the past year,
trading levels have increased to 14,364 Gigawatt hours for the year 1998,
providing revenues of $564.4 million. Columbia Energy Services actively trades
in cash and forward markets, as well as electricity futures traded on the four
New York Mercantile Exchanges. Columbia Energy Services is building its
capabilities and related infrastructure to deliver electricity to retail
customers in the Northeast.


                                       34
<PAGE>   35
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


Retail Energy Activity

Retail energy activity can be grouped into two broad strategic business units:
Major Accounts and Mass Markets. These retail business units market to end-use
customers, both for gas and power retail markets. Management believes that
Columbia Energy Services is favorably positioned for gas and electric retail
market unbundling and deregulation. During 1998, the Major Accounts strategic
business unit significantly increased the number of industrial and large
commercial customers served. Geographically, it expanded activity into two new
regions of the country, northeast and southeast, adding eight new states to
Columbia Energy Services' market territory. The Major Accounts group signed
several agreements to provide energy service with prominent national chain
restaurants and retail stores, including its first retail electric customer in
New York.

Columbia Energy Services initiated residential marketing programs in 10 states
in 1998 (Ohio, Pennsylvania, Michigan, Maryland, Indiana, Virginia, Georgia,
Kentucky, West Virginia and New Jersey). During 1998, Columbia Energy Services
increased its Mass Market customer base to over 363,000 or nearly 4 times the
number of customers since the beginning of the year.

During 1998, Columbia Energy Services entered the Georgia retail natural gas
market where it was certified by the Georgia Public Service Commission to sell
natural gas. All 1.2 million retail customers of an LDC located in Atlanta will
either choose a new natural gas supplier or be assigned to a provider. Also,
during 1998, Columbia Energy Services obtained its first residential electric
customers in Pennsylvania.

Columbia Energy Services is also offering diverse products and services related
to the deregulation of retail markets. For example, two energy efficiency
software products, developed by Columbia Energy Services, were launched late in
the third quarter of 1998. These software products are targeted toward helping
residential and commercial customers save money on energy costs.

Gross Margins

Gross margins of $42.7 million for 1998 more than doubled from the $20.6 million
in 1997. Electric power marketing sales, which began in late 1997, together with
increased gas sales represented the majority of the increase. Electric power
traded in 1998 was 14,364 Gigawatt hours while gas sales in 1998 of 1,581 Bcf
represented a 78 percent increase over 1997. Much of the growth in gas sales
came from increased lower-margin wholesale sales that are necessary to expand
Columbia Energy Services' base for future retail growth. Included in the results
for 1998 was the $6.5 million loss mentioned above.

The $20.6 million gross margin for 1997 was $4.1 million higher than for 1996,
reflecting gas sales of 888.4 Bcf that more than tripled the 1996 level due to
the significant growth of Columbia Energy Services' operations. The impact of
higher gas sales volumes was partially offset by a decrease in average margins.

Operating Loss

A 1998 operating loss of $59 million was $45.8 million greater than the $13.2
million loss in 1997, due to 1998 operating expenses that were $67.9 million
higher than the year earlier. The higher expenses related to the implementation
of Columbia Energy Services' strategy to build its systems and infrastructure,
including adding and retaining qualified staff. Included in these higher
expenses was the $16.3 million reserve, discussed above, and higher current
period expenses for costs associated with the development of new products and
services and customer acquisition costs related to adding new Mass Market retail
customers.


                                       35
<PAGE>   36
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


      STATEMENTS OF OPERATING INCOME FROM MARKETING OPERATIONS (UNAUDITED)

<TABLE>
<CAPTION>
Year Ended December 31, (in millions)           1998         1997         1996
- --------------------------------------------------------------------------------
<S>                                           <C>          <C>          <C>
OPERATING REVENUES
   Gas revenues                               $3,507.8     $2,187.0     $  728.0
   Power revenues                                564.4           --           --
- --------------------------------------------------------------------------------
   Total Operating Revenues                    4,072.2      2,187.0        728.0
   Less: Products purchased                    4,029.5      2,166.4        711.5
- --------------------------------------------------------------------------------
Gross Margin                                      42.7         20.6         16.5
- --------------------------------------------------------------------------------
OPERATING EXPENSES
   Operation and maintenance                      95.7         31.1         11.2
   Depreciation                                    4.1          1.6          0.3
   Other taxes                                     1.9          1.1          0.5
- --------------------------------------------------------------------------------
Total Operating Expenses                         101.7         33.8         12.0
- --------------------------------------------------------------------------------
OPERATING INCOME (LOSS)                       $  (59.0)    $  (13.2)    $    4.5
- --------------------------------------------------------------------------------
</TABLE>


                         MARKETING OPERATING HIGHLIGHTS

<TABLE>
<CAPTION>
                                            1998        1997      1996      1995      1994
- ------------------------------------------------------------------------------------------
<S>                                      <C>          <C>       <C>       <C>       <C>
CAPITAL EXPENDITURES ($ in millions)        16.0         5.1       0.8       1.0       0.2
- ------------------------------------------------------------------------------------------
MARKETING SALES
Gas (Bcf)                                1,581.0       888.4     259.6     131.6     111.2
Power (Gwh)                               14,364          --        --        --        --
- ------------------------------------------------------------------------------------------
</TABLE>


                                       36
<PAGE>   37
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


                  PROPANE, POWER GENERATION AND LNG OPERATIONS

During 1998, Columbia Propane Corporation (Columbia Propane) and Columbia
Electric Corporation (Columbia Electric) were involved in several transactions
designed to increase the contribution by Columbia's nonregulated companies to
consolidated results. Columbia Propane purchased the assets of three propane
companies and Columbia Electric announced its participation in two cogeneration
projects.

Propane

During 1998, Columbia Propane purchased the propane assets of three companies
that in total added approximately 12,500 new customers and 6.4 million gallons
of annual propane sales to Columbia Propane.

Power Generation

Columbia Electric's primary focus has been the development, ownership and
operation of natural gas-fueled cogeneration power plants that sell electric
power to local electric utilities under long-term contracts. Columbia Electric
is part owner in three cogeneration projects that have a total capacity of
approximately 250 megawatts and produce both electricity and useful thermal
energy fueled principally by natural gas.

In June 1998, Columbia Electric and LG&E Power Inc., a subsidiary of LG&E Energy
Corporation, announced an agreement for Columbia to participate in the
development of a gas-fired cogeneration project. The facility will have a total
equivalent capacity of approximately 550 megawatts and will provide steam and
electric services to a Reynolds Metals plant in Gregory, Texas. The project,
Gregory Power Partners, will also provide electricity to the Texas energy market
and is expected to begin commercial operation in the Electric Reliability
Council of Texas (ERCOT) region in the summer of 2000. Construction began in
August 1998 and financing for the $257 million project was secured in November
of 1998.

In January 1998, Columbia Electric and Westcoast Energy Inc. signed a joint
ownership agreement to develop three gas-fired electric generation plants by
2001. In total, the three plants would provide approximately 1,000 megawatts of
electricity using approximately 160 MMcf per day of natural gas. In August 1998,
the parties formed a limited liability company, which subsequently purchased a
site in Eddystone, Pennsylvania for the construction of a 500 megawatt, natural
gas-fired electric generation plant. The plant, to be called the Liberty
Electric Power Plant, is expected to cost about $300 million to develop, and
would consume about 80 MMcf per day of natural gas. Each of the sponsors will
own a 50% interest in the project. The exact locations of the other two plants
have yet to be determined.

Capital Expenditure Program

A large portion of the $20.1 million 1998 capital expenditures program was
allocated to propane acquisition activities. The 1999 capital expenditure
program is estimated at $129 million and includes amounts primarily for
acquisitions, as well as for additional investments in Columbia's subsidiary,
Columbia Transmission Telecommunications Corporation, for the development of a
dark fiber optics network, as well as for continued investment in the Cove Point
LNG facility.

Commodity Hedging

Columbia Propane purchases propane and places it in storage for future sale.
Columbia Propane sells commodity futures on a portion of its inventory at the
time of purchase to hedge against the risk of decreasing prices.

Net Revenues 

Net revenues of $55.1 million for 1998 decreased $2.1 million from 1997. The
decrease largely reflects the net effect of Columbia Electric's $3.2 million
revenue improvement recorded in the first quarter of 1997 from the assumption of
a cogeneration partnership fuel transportation contract. This decrease was
partially offset by an increase in propane net revenues of $1.3 million, due to
higher margins achieved in the first quarter of 1998 and additional retail sales
attributable to recent acquisitions. Total propane volumes for 1998 decreased
4.4 million gallons from 1997 due to warmer weather and lower spot sales.

Net revenues for 1997 increased $11.3 million over 1996 to $57.2 million. Net
revenues for Columbia Propane in 1997 increased $1.4 million compared to 1996
due to 11% higher margins, which were partially offset by a 7% decrease in
volumes resulting from the warmer than normal weather experienced in the first
quarter of 1997 and lower spot market sales activity. 


                                       37
<PAGE>   38
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


Operating Income 

Operating income of $10.7 million for 1998 decreased $5.6 million from 1997,
primarily reflecting the decline in net revenues and a $3.5 million increase in
operating expenses due to the recent propane acquisitions and additional
start-up costs for new services.

Operating income of $16.3 million was recorded in 1997, up $6.7 million over
1996. Operation and maintenance expense for 1997 increased over 1996 as start-up
costs for new services led to higher operating costs.

     STATEMENTS OF PROPANE, POWER GENERATION AND LNG OPERATIONS (UNAUDITED)


<TABLE>
<CAPTION>
Year Ended December 31, (in millions)              1998        1997        1996
- --------------------------------------------------------------------------------
<S>                                              <C>         <C>         <C>
NET REVENUES
   Propane revenues                              $  63.1     $  70.4     $  74.1
   Less: Products purchased                         34.6        43.2        48.3
- --------------------------------------------------------------------------------
   Net Propane Revenues                             28.5        27.2        25.8
- --------------------------------------------------------------------------------
   Power generation                                  8.3        10.6         7.3
   Other revenues                                   18.3        19.4        12.8
- --------------------------------------------------------------------------------
Net Revenues                                        55.1        57.2        45.9
- --------------------------------------------------------------------------------
OPERATING EXPENSES
   Operation and maintenance                        37.2        35.3        31.6
   Depreciation                                      5.1         3.6         2.8
   Other taxes                                       2.1         2.0         1.9
- --------------------------------------------------------------------------------
Total Operating Expenses                            44.4        40.9        36.3
- --------------------------------------------------------------------------------
OPERATING INCOME                                 $  10.7     $  16.3     $   9.6
- --------------------------------------------------------------------------------
</TABLE>

             PROPANE, POWER GENERATION AND LNG OPERATING HIGHLIGHTS

<TABLE>
<CAPTION>
                                           1998         1997        1996        1995        1994
- --------------------------------------------------------------------------------------------------
<S>                                       <C>           <C>         <C>         <C>         <C>
CAPITAL EXPENDITURES ($ in millions)         20.1          9.9         5.5         9.0         4.5
- --------------------------------------------------------------------------------------------------
PROPANE
Gallons sold (millions)                      66.5         70.9        75.9        68.9        68.5
Customers                                 113,748       96,954      79,650      74,308      68,218
- --------------------------------------------------------------------------------------------------
</TABLE>


                                       38
<PAGE>   39
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA


                               BANKRUPTCY MATTERS

On November 28, 1995, Columbia and its wholly owned subsidiary, Columbia
Transmission emerged from Chapter 11 protection of the United States Bankruptcy
Code under the jurisdiction of the United States Bankruptcy Court for the
District of Delaware (Bankruptcy Court). Both Columbia and Columbia Transmission
had operated under Chapter 11 protection since July 31, 1991. In settlement of
its prepetition obligations, Columbia distributed approximately $3.6 billion to
its creditors, which included $2.3 billion in payment of Columbia's prepetition
debt and approximately $1 billion of interest on that debt. Certain residual
unresolved bankruptcy-related matters are still within the jurisdiction of the
Bankruptcy Court.

In July 1998, the Bankruptcy Court, granting a motion by Columbia Transmission,
entered an Order allowing the claim of the New Bremen Corporation in accordance
with the Claims Mediator's Report and Recommendations and the decision of the
U.S. 5th Circuit Court of Appeals. In August 1998, New Bremen filed a notice of
appeal of this order to the U.S. District Court for the District of Delaware.
This litigation is the last remaining producer claim in Columbia Transmission's
bankruptcy proceeding. In the first quarter of 1999, Columbia Transmission
anticipates reversing that portion of its producer settlement reserve that is in
excess of the amount needed to resolve remaining producer-related issues, which
will result in an improvement to income.


ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Information required by this item is in Item 7 on page 19.


                                       39
<PAGE>   40
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA

<TABLE>
<CAPTION>
Index                                                                       Page
- --------------------------------------------------------------------------------
<S>                                                                         <C>
Report of Independent Public Accountants .................................    41
Statements  of Consolidated Income .......................................    42
Consolidated Balance Sheets ..............................................    43
Statements of Consolidated Cash Flows ....................................    45
Statements of Consolidated Common Stock Equity ...........................    46
Notes of Consolidated Financial Statements ...............................    47
Schedule II - Valuation and Qualifying Accounts ..........................    70
- --------------------------------------------------------------------------------
</TABLE>


                                       40
<PAGE>   41
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA (continued)


                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS


To the Shareholders of Columbia Energy Group.:

We have audited the accompanying consolidated balance sheets of Columbia Energy
Group (a Delaware corporation, the "Corporation") and subsidiaries as of
December 31, 1998 and 1997, and the related statements of consolidated income,
cash flows and common stock equity for each of the three years in the period
ended December 31, 1998. These financial statements are the responsibility of
the Corporation's management. Our responsibility is to express an opinion on
these financial statements based on our audits.

We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of the Corporation and
subsidiaries as of December 31, 1998 and 1997, and the results of their
operations and their cash flows for each of the three years in the period ended
December 31, 1998, in conformity with generally accepted accounting principles.

Our audits were made for the purpose of forming an opinion on the basic
consolidated financial statements taken as a whole. The schedule listed in the
Index to Item 8, Financial Statements and Supplementary Data, is presented for
purposes of complying with the Securities and Exchange Commission's rules and is
not part of the basic consolidated financial statements. This schedule has been
subjected to the auditing procedures applied in the audits of the basic
consolidated financial statements and, in our opinion, fairly states in all
material respects the financial data required to be set forth therein in
relation to the basic consolidated financial statements taken as a whole.




ARTHUR ANDERSEN LLP


New York, New York
February 11, 1999


                                       41
<PAGE>   42
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA (continued)


                        STATEMENTS OF CONSOLIDATED INCOME
                     Columbia Energy Group and Subsidiaries

<TABLE>
<CAPTION>
Year Ended December 31, (in millions, except per share amounts)       1998           1997           1996
- -----------------------------------------------------------------------------------------------------------
<S>                                                                <C>            <C>            <C>
NET REVENUES
   Energy sales                                                    $  5,731.8     $  4,325.2     $  2,713.4
   Less:  Products purchased                                          4,654.0        3,125.5        1,466.6
- -----------------------------------------------------------------------------------------------------------
   Gross Margin                                                       1,077.8        1,199.7        1,246.8
   Transportation                                                       557.5          518.9          476.8
   Production gas sales                                                  51.6           30.4           37.7
   Other                                                                210.2          166.5          111.6
- -----------------------------------------------------------------------------------------------------------
Total Net Revenues                                                    1,897.1        1,915.5        1,872.9
- -----------------------------------------------------------------------------------------------------------
OPERATING EXPENSES
   Operation                                                            810.1          862.1          854.5
   Maintenance                                                           91.5          100.2          111.4
   Depreciation and depletion                                           235.2          221.3          215.2
   Other taxes                                                          220.3          222.5          213.6
- -----------------------------------------------------------------------------------------------------------
Total Operating Expenses                                              1,357.1        1,406.1        1,394.7
- -----------------------------------------------------------------------------------------------------------
OPERATING INCOME                                                        540.0          509.4          478.2
- -----------------------------------------------------------------------------------------------------------
OTHER INCOME (DEDUCTIONS)
   Interest income and other, net (Note 14)                              13.4           40.4           26.1
   Interest expense and related charges (Note 15)                      (152.4)        (157.6)        (166.8)
- -----------------------------------------------------------------------------------------------------------
Total Other Income (Deductions)                                        (139.0)        (117.2)        (140.7)
- -----------------------------------------------------------------------------------------------------------
INCOME BEFORE INCOME TAXES                                              401.0          392.2          337.5
Income Taxes (Note 7)                                                   131.8          118.9          115.9
- -----------------------------------------------------------------------------------------------------------
NET INCOME                                                         $    269.2     $    273.3     $    221.6
- -----------------------------------------------------------------------------------------------------------
EARNINGS PER SHARE OF COMMON STOCK*                                $     3.23     $     3.29     $     2.75
DILUTED EARNINGS PER SHARE OF COMMON STOCK*                        $     3.21     $     3.27     $     2.74
- -----------------------------------------------------------------------------------------------------------
DIVIDENDS PAID PER SHARE OF COMMON STOCK*                          $     0.77     $     0.60     $     0.40
- -----------------------------------------------------------------------------------------------------------
AVERAGE COMMON SHARES OUTSTANDING (thousands)*                         83,382         83,100         80,681
DILUTED AVERAGE COMMON SHARES (thousands)*                             83,748         83,594         80,919
- -----------------------------------------------------------------------------------------------------------
</TABLE>

The accompanying Notes to Consolidated Financial Statements are an integral part
of these statements.

*     All per share amounts, average common shares outstanding and diluted
      average common shares have been restated to reflect a three-for-two common
      stock split, in the form of a stock dividend, effective June 15, 1998. See
      Note 3 of Notes to Consolidated Financial Statements.


                                       42
<PAGE>   43
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA (continued)


                           CONSOLIDATED BALANCE SHEETS
                     Columbia Energy Group and Subsidiaries

<TABLE>
<CAPTION>
ASSETS as of December 31, (in millions)                     1998         1997
- --------------------------------------------------------------------------------
<S>                                                       <C>          <C>
PROPERTY, PLANT AND EQUIPMENT                           
   Gas utility and other plant, at original cost          $7,687.8     $7,368.9
   Accumulated depreciation                               (3,592.3)    (3,481.5)
- --------------------------------------------------------------------------------
   Net Gas Utility and Other Plant                         4,095.5      3,887.4
- --------------------------------------------------------------------------------
   Gas and oil producing properties, full cost method   
      United States cost center                              714.1        660.2
      Canadian cost center                                     5.0           --
   Accumulated depletion                                    (225.4)      (196.0)
- --------------------------------------------------------------------------------
   Net Gas and Oil Producing Properties                      493.7        464.2
- --------------------------------------------------------------------------------
Net Property, Plant and Equipment                          4,589.2      4,351.6
- --------------------------------------------------------------------------------
INVESTMENTS AND OTHER ASSETS                            
   Accounts receivable - noncurrent                           26.2          1.6
   Unconsolidated affiliates                                  81.6         74.1
   Other                                                      14.3          9.5
- --------------------------------------------------------------------------------
Total Investments and Other Assets                           122.1         85.2
- --------------------------------------------------------------------------------
CURRENT ASSETS                                          
   Cash and temporary cash investments                        26.3         28.7
   Accounts receivable                                  
      Customer (less allowance for doubtful accounts    
         of $34.2 and $18.7, respectively)                   948.9        815.8
      Other                                                   56.0         52.7
   Gas inventory                                             186.0        226.8
   Other inventories - at average cost                        26.8         35.6
   Prepayments                                               115.9        107.7
   Regulatory assets                                          59.5         64.6
   Underrecovered gas costs                                   24.5         41.4
   Deferred property taxes                                    80.0         80.8
   Exchange gas receivable                                   187.4        189.0
   Other                                                      69.2         64.6
- --------------------------------------------------------------------------------
Total Current Assets                                       1,780.5      1,707.7
- --------------------------------------------------------------------------------
REGULATORY ASSETS                                            391.4        400.9
DEFERRED CHARGES                                              85.5         66.9
- --------------------------------------------------------------------------------
TOTAL ASSETS                                              $6,968.7     $6,612.3
- --------------------------------------------------------------------------------
</TABLE>

The accompanying Notes to Consolidated Financial Statements are an integral part
of these statements.

*     The common shares outstanding at December 31, 1997 do not reflect the
      three-for-two common stock split, in the form of a stock dividend,
      effective June 15, 1998.


                                       43
<PAGE>   44
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA (continued)


<TABLE>
<CAPTION>
CAPITALIZATION AND LIABILITIES as of December 31, (in millions)      1998         1997
- ----------------------------------------------------------------------------------------
<S>                                                                <C>          <C>
COMMON STOCK EQUITY
   Common stock, par value $10 per share - issued
     83,511,878 and 55,495,460* shares, respectively               $  835.1     $  554.9
   Additional paid in capital                                         761.8        754.2
   Retained earnings                                                  409.5        482.7
   Unearned employee compensation                                      (0.9)        (1.1)
   Accumulated Other Comprehensive Income:
     Foreign currency translation adjustment                           (0.2)          --
- ----------------------------------------------------------------------------------------
Total Common Stock Equity                                           2,005.3      1,790.7
LONG-TERM DEBT (Note 10)                                            2,003.1      2,003.5
- ----------------------------------------------------------------------------------------
Total Capitalization                                                4,008.4      3,794.2
- ----------------------------------------------------------------------------------------
CURRENT LIABILITIES
   Short-term debt (Note 11)                                          144.8        328.1
   Accounts and drafts payable                                        710.7        536.7
   Accrued taxes                                                      205.9        140.9
   Accrued interest                                                    17.3         29.4
   Estimated rate refunds                                              59.2         68.4
   Estimated supplier obligations                                      72.4         73.9
   Overrecovered gas costs                                             34.3         84.6
   Transportation and exchange gas payable                            134.2         89.2
   Other                                                              312.9        367.0
- ----------------------------------------------------------------------------------------
Total Current Liabilities                                           1,691.7      1,718.2
- ----------------------------------------------------------------------------------------
OTHER LIABILITIES AND DEFERRED CREDITS
   Deferred income taxes - noncurrent                                 655.3        618.4
   Investment tax credits                                              34.1         35.6
   Postretirement benefits other than pensions                        103.7        148.8
   Regulatory liabilities                                              44.0         41.3
   Deferred revenue                                                   191.4         67.0
   Other                                                              240.1        188.8
- ----------------------------------------------------------------------------------------
Total Other Liabilities and Deferred Credits                        1,268.6      1,099.9
- ----------------------------------------------------------------------------------------
COMMITMENTS AND CONTINGENCIES (Note 13)                                  --           --
- ----------------------------------------------------------------------------------------
TOTAL CAPITALIZATION AND LIABILITIES                               $6,968.7     $6,612.3
- ----------------------------------------------------------------------------------------
</TABLE>


                                       44
<PAGE>   45
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTAL DATA (continued)


                      STATEMENTS OF CONSOLIDATED CASH FLOWS
                     Columbia Energy Group and Subsidiaries

<TABLE>
<CAPTION>
Year Ended December 31, (in millions)                            1998        1997        1996
- ----------------------------------------------------------------------------------------------
<S>                                                            <C>         <C>         <C>
OPERATING ACTIVITIES
   Net income                                                  $ 269.2     $ 273.3     $ 221.6
   Adjustments for items not requiring (providing) cash:
      Depreciation and depletion                                 235.2       221.3       215.2
      Deferred income taxes                                       31.6        29.3        78.1
      Earnings from equity investment, net of distributions       (8.5)        2.4         9.2
      Other - net                                                121.4        32.2        (5.7)
- ----------------------------------------------------------------------------------------------
                                                                 648.9       558.5       518.4
   Changes in components of working capital:
      Accounts receivable                                       (139.5)     (199.2)      (64.3)
      Income tax refunds                                            --          --       271.5
      Gas inventory                                               40.8        11.0       (65.6)
      Prepayments                                                 (8.2)      (33.9)      (16.3)
      Accounts payable                                           230.7       186.8       160.8
      Accrued taxes                                               46.7       (30.4)      (85.5)
      Accrued interest                                           (12.1)       (1.2)      (71.5)
      Estimated rate refunds                                      (9.2)      (45.6)       17.8
      Estimated supplier obligations                              (1.5)      (41.2)      (63.2)
      Under/Overrecovered gas costs                              (33.4)      147.9      (146.3)
      Exchange gas receivable/payable                             47.3       (89.5)       46.9
      Other working capital                                      (48.8)        5.0       (25.7)
- ----------------------------------------------------------------------------------------------
Net Cash From Operations                                         761.7       468.2       477.0
- ----------------------------------------------------------------------------------------------
INVESTMENT ACTIVITIES
   Capital expenditures                                         (462.9)     (420.5)     (316.4)
   Proceeds received on the sale of
      Columbia Gas Development Corp.                                --          --       187.8
   Purchase of Alamco, Inc.                                         --       (99.4)         --
   Other investments - net                                       (12.5)       (9.1)        2.7
- ----------------------------------------------------------------------------------------------
Net Investment Activities                                       (475.4)     (529.0)     (125.9)
- ----------------------------------------------------------------------------------------------
FINANCING ACTIVITIES
   Retirement of preferred stock                                    --          --      (400.0)
   Dividends paid                                                (63.9)      (49.9)      (32.1)
   Issuance of common stock                                       10.5        11.7       250.8
   Issuance (repayment) of short-term debt                      (182.4)       77.1       (88.9)
   Other financing activities                                    (52.9)        0.8       (39.1)
- ----------------------------------------------------------------------------------------------
Net Financing Activities                                        (288.7)       39.7      (309.3)
- ----------------------------------------------------------------------------------------------
Increase (Decrease) in cash and temporary cash investments        (2.4)      (21.1)       41.8
Cash and temporary cash investments at beginning of year          28.7        49.8         8.0
- ----------------------------------------------------------------------------------------------
CASH AND TEMPORARY CASH INVESTMENTS AT END OF YEAR             $  26.3     $  28.7     $  49.8
- ----------------------------------------------------------------------------------------------
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
   Cash paid for interest                                      $ 147.0     $ 145.4     $ 150.9
   Cash paid for income taxes (net of refunds)                 $  38.3     $  90.7     $ (93.4)
- ----------------------------------------------------------------------------------------------
</TABLE>

The accompanying Notes to Consolidated Financial Statements are an integral part
of these statements.


                                       45
<PAGE>   46
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


                 STATEMENTS OF CONSOLIDATED COMMON STOCK EQUITY
                     Columbia Energy Group and Subsidiaries

<TABLE>
<CAPTION>
                                                       Common Stock*                                               
                                            -----------------------------------
                                               Shares                            Additional               Unearned  
                                            Outstanding**    Par      Treasury    Paid In    Retained     Employee  
(in millions, except for share amounts)      (Thousands)    Value       Stock     Capital    Earnings   Compensation
- --------------------------------------------------------------------------------------------------------------------
<S>                                         <C>            <C>        <C>        <C>         <C>        <C>
Balance at December 31, 1995                    49,204     $  506.2   $  (57.8)   $  595.8   $   69.8     $     --  
Net income                                                                                      221.6               
Cash dividends:                                                                                                     
   Common stock                                                                                 (32.1)              
Common stock issued:                                                                                                
   Public offering                               5,750         43.3       57.8       137.5                          
   Long-term incentive plan                        310          3.1                    9.9                    (1.5) 
- --------------------------------------------------------------------------------------------------------------------
Balance at December 31, 1996                    55,264        552.6         --       743.2      259.3         (1.5) 
Net income                                                                                      273.3               
Cash dividends:                                                                                                     
   Common stock                                                                                 (49.9)              
Common stock issued:                                                                                                
   Long-term incentive plan                        232          2.3                   11.0                     0.4  
- --------------------------------------------------------------------------------------------------------------------
Balance at December 31, 1997                    55,496        554.9         --       754.2      482.7         (1.1) 
Comprehensive income:                                                                                               
   Net income                                                                                   269.2               
   Foreign currency translation adjustment                                                                          
Comprehensive income                                                                                                
Cash dividends:                                                                                                     
   Common stock                                                                                 (63.9)              
Common stock issued:                                                                                                
   Long-term incentive plan                        231          2.3                    7.6                     0.2  
  Three-for-two stock split                     27,785        277.9                            (278.5)              
- --------------------------------------------------------------------------------------------------------------------
BALANCE AT DECEMBER 31, 1998                    83,512     $  835.1   $     --    $  761.8   $  409.5     $   (0.9) 
- --------------------------------------------------------------------------------------------------------------------

<CAPTION>                                   
                                               Accumulated
                                                  Other               
                                              Comprehensive           
(in millions, except for share amounts)           Income      Total   
- --------------------------------------------------------------------- 
<S>                                           <C>            <C>      
Balance at December 31, 1995                     $     --    $1,114.0 
Net income                                                      221.6 
Cash dividends:                                                       
   Common stock                                                 (32.1)
Common stock issued:                                                  
   Public offering                                              238.6 
   Long-term incentive plan                                      11.5 
- ----------------------------------------------------------------------
Balance at December 31, 1996                           --     1,553.6 
Net income                                                      273.3 
Cash dividends:                                                       
   Common stock                                                 (49.9)
Common stock issued:                                                  
   Long-term incentive plan                                      13.7 
- ----------------------------------------------------------------------
Balance at December 31, 1997                           --     1,790.7 
Comprehensive income:                                                 
   Net income                                                         
   Foreign currency translation adjustment           (0.2)            
Comprehensive income                                            269.0 
Cash dividends:                                                       
   Common stock                                                 (63.9)
Common stock issued:                                                  
   Long-term incentive plan                                      10.1 
  Three-for-two stock split                                      (0.6)
- ----------------------------------------------------------------------
BALANCE AT DECEMBER 31, 1998                     $   (0.2)   $2,005.3 
- ----------------------------------------------------------------------
</TABLE>

The accompanying Notes to Consolidated Financial Statements are an integral part
of these statements.

*     100 million shares authorized at December 31, 1998, 1997, 1996 and 1995 -
      $10 par value.

**    The common shares outstanding at December 31, 1997, 1996 and 1995 do not
      reflect the three-for-two common stock split, in the form of a stock
      dividend, effective June 15, 1998.


                                       46
<PAGE>   47
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS


1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

A. PRINCIPLES OF CONSOLIDATION. The consolidated financial statements include
the accounts of the Columbia Energy Group (Columbia) and all subsidiaries. All
intercompany accounts and transactions have been eliminated. Certain
reclassifications have been made to the 1997 and 1996 financial statements to
conform to the 1998 presentation.

B. CASH AND CASH EQUIVALENTS. Columbia considers all highly liquid short-term
investments to be cash equivalents.

C. EARNINGS PER SHARE. Financial Accounting Standards Board Statement of
Financial Accounting Standards No. 128, "Earnings Per Share" (SFAS No. 128),
requires dual presentation of Basic and Diluted earnings per share (EPS) by
entities with complex capital structures and also requires restatement of all
prior period EPS data presented. Basic EPS includes no dilution and is computed
by dividing income available to common stockholders by the weighted-average
number of common shares outstanding for the period. Diluted EPS reflects the
potential dilution if certain securities are converted into common stock.

The computation of diluted average common shares follows:

<TABLE>
<CAPTION>
Diluted Average Common Shares Computation              1998      1997      1996
- --------------------------------------------------------------------------------
<S>                                                   <C>       <C>       <C>  
Net Income  ($ in millions)                            269.2     273.3     221.6
- --------------------------------------------------------------------------------
Denominator (thousands)
     Average common shares outstanding                83,382    83,100    80,681
     Dilutive potential common shares - options          366       494       238
- --------------------------------------------------------------------------------
DILUTED AVERAGE COMMON SHARES                         83,748    83,594    80,919
- --------------------------------------------------------------------------------
</TABLE>

The number of shares reflect a three-for-two common stock split, in the form of
a stock dividend, effective June 15, 1998.

D. BASIS OF ACCOUNTING FOR RATE-REGULATED SUBSIDIARIES. Statement of Financial
Accounting Standards No. 71, "Accounting for the Effects of Certain Types of
Regulation" (SFAS No. 71), provides that rate-regulated public utilities account
for and report assets and liabilities consistent with the economic effect of the
way in which regulators establish rates, if the rates established are designed
to recover the costs of providing the regulated service and if the competitive
environment makes it reasonable to assume that such rates can be charged and
collected. Columbia's transmission and gas distribution subsidiaries follow the
accounting and reporting requirements of SFAS No. 71. Certain expenses and
credits subject to utility regulation or rate determination normally reflected
in income are deferred on the balance sheet and are recognized in income as the
related amounts are included in service rates and recovered from or refunded to
customers.


                                       47
<PAGE>   48
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


Information for assets and liabilities subject to utility regulation and rate
determination are as follows:

<TABLE>
<CAPTION>
                                                         TRANSMISSION        DISTRIBUTION
                                                         SUBSIDIARIES        SUBSIDIARIES
                                                        -----------------------------------
At December 31, ($ in millions)                         1998      1997      1998      1997
- -------------------------------------------------------------------------------------------
<S>                                                     <C>       <C>       <C>       <C>
ASSETS
  Environmental costs                                   136.7     125.8       6.2       7.4
  Postemployment and postretirement benefits costs       60.3      64.6     113.6     121.8
  Percent of income plan receivables                       --        --      15.3      22.6
  Retirement income plan costs                           15.2      21.7      16.6      19.2
  Regulatory effects of accounting for income taxes        --        --      55.8      50.8
  Post in-service carrying charges                         --        --      16.9      18.3
  Underrecovered gas costs                                 --        --      24.5      41.4
  Other                                                   8.1       7.4       6.2       5.9
- -------------------------------------------------------------------------------------------
TOTAL REGULATORY ASSETS                                 220.3     219.5     255.1     287.4
- -------------------------------------------------------------------------------------------
LIABILITIES
  Rate refunds and reserves                              49.1      55.9      10.1      12.5
  Overrecovered gas costs                                  --        --      34.3      84.6
  Regulatory effects of accounting for income taxes      17.3      19.5      21.9      24.1
  Other                                                  22.7       7.5       6.6        --
- -------------------------------------------------------------------------------------------
TOTAL REGULATORY LIABILITIES                             89.1      82.9      72.9     121.2
- -------------------------------------------------------------------------------------------
</TABLE>

E. GAS UTILITY AND OTHER PLANT AND RELATED DEPRECIATION. Property, plant and
equipment (principally utility plant) are stated at original cost. The cost of
gas utility and other plant of the rate-regulated subsidiaries includes an
allowance for funds used during construction (AFUDC). Property, plant and
equipment of other subsidiaries includes interest during construction (IDC). The
1998 before-tax rates for AFUDC and IDC were 7.43% and 6.96%, respectively. The
1997 and 1996 before-tax rates for AFUDC were 7.09% and 6.15%, respectively, and
for IDC were 7.05% and 6.9%, respectively.

Improvements and replacements of retirement units are capitalized at cost. When
units of property are retired, the accumulated provision for depreciation is
charged with the cost of the units and the cost of removal, net of salvage.
Maintenance, repairs and minor replacements of property are charged to expense.

Columbia's subsidiaries provide for annual depreciation on a composite
straight-line basis. The average annual depreciation rate for the transmission
subsidiaries' property was 2.4% in 1998 and 2.5% in 1997 and 1996. The average
annual depreciation rate for the distribution subsidiaries' property was 3.1% in
1998 and 3.2% in 1997 and 1996.

F. GAS AND OIL PRODUCING PROPERTIES. Columbia's subsidiaries engaged in
exploring for and developing gas and oil reserves follow the full cost method of
accounting. Under this method of accounting, all productive and nonproductive
costs directly identified with acquisition, exploration and development
activities including certain payroll and other internal costs are capitalized.
Depletion is based upon the ratio of current year revenues to expected total
revenues, utilizing current prices, over the life of production. If costs exceed
the sum of the estimated present value of the net future gas and oil revenues
and the lower of cost or estimated value of unproved properties, an amount
equivalent to the excess is charged to current depletion expense. Gains or
losses on the sale or other disposition of gas and oil properties are normally
recorded as adjustments to capitalized costs, except in the case of a sale of a
significant amount of properties, which would be reflected in the income
statement.

G. ACCOUNTING FOR RISK MANAGEMENT ACTIVITIES. Subsidiaries in Columbia's
exploration and production, marketing and propane operations are exposed to
market risk due primarily to fluctuations in commodity prices. In order to help
minimize this risk, Columbia has adopted a policy that provides for the use of
commodity derivative instruments to help ensure stable cash flow, favorable
prices and margins as well as to help capture any long-term increases in value.
In accordance with Statement of Financial Accounting Standards No. 80,
"Accounting for Futures Contracts," a futures contract qualifies as a hedge if
the commodity to be hedged is exposed to price risk and the futures contract
reduces that exposure and is designated as a hedge. The hedging objectives
include assurance of stable and known cash flows, fixing favorable prices and
margins when they become available and participation in any long-term increases
in value. In no event does Columbia enter into trading positions that are not
effectively connected with its business.


                                       48
<PAGE>   49
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


Columbia's exploration and production company and propane operations utilize
futures and options as well as commodity price swaps and basis swaps. Futures
help manage commodity price risk by fixing prices for future production volumes
as well as protecting the value and margins of propane inventories. The options
provide a price floor for future production volumes and the opportunity to
benefit from any increases in prices. Swaps are negotiated and executed
over-the-counter and are structured to provide the same risk protection as
futures and options. Basis swaps are used to manage risk by fixing the basis or
differential that exists between a delivery location index and the commodity
futures prices.

Premiums paid for option agreements are included as current assets in the
consolidated balance sheet until they are exercised or expire. Margin
requirements for natural gas and propane futures are also recorded as current
assets. Unrealized gains and losses on all futures contracts, designated as
hedges, are deferred on the consolidated balance sheet as either current assets
or other deferred credits. Realized gains and losses from the settlement of
natural gas futures, options and swaps are included in revenues or products
purchased as appropriate, concurrent with the associated physical transaction.
Realized gains and losses from the settlement of propane futures contracts are
included in products purchased. The cash flows from commodity hedging are
included in operating activities in the consolidated statement of cash flows.

Columbia's gas and power marketing operations utilize futures contracts and
basis swaps to help assure adequate margins on the purchase and resale of
natural gas and electric power. During the fourth quarter of 1998, certain
unusual trading activity in Columbia's gas marketing operations resulted in a
loss. Consistent with generally accepted accounting principles, Columbia applied
mark-to-market accounting for its physical and financial natural gas positions.
The market value of the open physical and financial positions at December 31,
1998, reflected a loss of approximately $6.5 million, which was recorded by
Columbia. Effective January 1, 1999, Columbia will utilize mark-to-market
accounting for all of its gas and power marketing operations and will mark all
physical and financial positions to market in accordance with recently issued
EITF Statement 98-10.

Columbia and its subsidiaries are exposed to credit losses in the event of
nonperformance by the counterparties to its various financial contracts.
Management has evaluated such risk and believes that overall business risk is
significantly reduced as these financial contracts are primarily with major
investment grade financial institutions or their affiliates.

Columbia utilizes fixed-to-floating interest rate swap agreements to modify the
interest characteristics of a portion of its outstanding long-term debt. The
differentials between amounts received and paid under the agreements are
recorded as adjustments to interest expense.

H. GAS INVENTORY. The distribution subsidiaries' gas inventory is carried at
cost on a last-in, first-out (LIFO) basis. The replacement cost of gas inventory
at December 31, 1998, was less than the carrying value by approximately $5
million. Liquidation of LIFO layers related to gas delivered by the distribution
subsidiaries does not affect income since the effect is passed through to
customers as part of purchased gas adjustment tariffs.

I. INCOME TAXES AND INVESTMENT TAX CREDITS. Columbia and its subsidiaries record
income taxes to recognize full interperiod tax allocations. Under the liability
method of income tax accounting, deferred income taxes are recognized for the
tax consequences of temporary differences by applying enacted statutory tax
rates applicable to future years to differences between the financial statement
carrying amounts and the tax basis of existing assets and liabilities.

Previously recorded investment tax credits of the regulated subsidiaries were
deferred and are being amortized over the life of the related properties to
conform with regulatory policy.

J. ESTIMATED RATE REFUNDS. Certain rate-regulated subsidiaries collect revenues
subject to refund pending final determination in rate proceedings. In connection
with such revenues, estimated rate refund liabilities are recorded which reflect
management's current judgment of the ultimate outcome of the proceedings. No
provisions are made when, in the opinion of management, the facts and
circumstances preclude a reasonable estimate of the outcome.

K. DEFERRED GAS PURCHASE COSTS. Columbia's gas distribution subsidiaries defer
differences between gas purchase costs and the recovery of such costs in
revenues, and adjust future billings for such deferrals on a basis consistent
with applicable tariff provisions.


                                       49
<PAGE>   50
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


L. REVENUE RECOGNITION. Columbia's gas distribution subsidiaries bill customers
on a monthly cycle billing basis. Revenues are recorded on the accrual basis
including an estimate for gas delivered but unbilled at the end of each
accounting period.

M. ENVIRONMENTAL EXPENDITURES. Columbia accrues for costs associated with
environmental remediation obligations when such costs are probable and can be
reasonably estimated, regardless of when expenditures are made. The undiscounted
estimated future expenditures are based on currently enacted laws and
regulations, existing technology and, when possible, site-specific costs. The
reserve is adjusted as further information is developed or circumstances change.
Rate-regulated subsidiaries applying SFAS No. 71 establish a regulatory asset on
the balance sheet to the extent that future recovery of environmental
remediation costs is expected through the regulatory process.

N. USE OF ESTIMATES. The preparation of financial statements in conformity with
generally accepted accounting principles requires management to make estimates
and assumptions that affect reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. Actual results could differ from those estimates.

O. STOCK OPTIONS AND AWARDS. Statement of Financial Accounting Standards No.
123, "Accounting for Stock-Based Compensation" (SFAS No. 123), encourages, but
does not require, entities to adopt the fair value method of accounting for
stock-based compensation plans. This statement requires the value of the option
at the date of grant be amortized over the vesting period of the option.
Columbia continues to apply Accounting Principles Board Opinion No. 25,
"Accounting for Stock Issued to Employees" (APB Opinion No. 25).

For stock appreciation rights, compensation expense is recognized on the
aggregate difference between the market price of Columbia's stock and the option
price. Restricted stock awards are recorded as deferred compensation in the
consolidated balance sheet at the date of grant. Compensation expense related to
restricted stock awards is recognized ratably over the vesting period.
Compensation expense related to contingent stock awards is recognized over the
vesting period. Columbia sets the grant price of the options at the market price
of the stock on the grant date. In accordance with APB Opinion No. 25, expense
related to stock options is measured by the difference between the grant price
and Columbia's stock price on the measurement date (grant date). Since the
difference between the grant price and Columbia's stock price on the measurement
date is de minimis, no compensation expense is recognized. When stock options
are exercised, common stock is credited for the par value of shares issued and
additional paid in capital is credited with the consideration in excess of par.

2. REGULATORY MATTERS

A. In April 1997, the Federal Energy Regulatory Commission (FERC) approved a
settlement of Columbia Gas Transmission Corporation's (Columbia Transmission)
rate case which provides for an increase in revenues to recover the higher costs
incurred since 1991. The settlement also provides an opportunity for the
recovery of Columbia Transmission's net investment in gathering and certain gas
processing facilities and the continued use of system-wide rates, commonly known
as postage-stamp rates, in lieu of zone rates. Under the settlement, Columbia
Transmission will not place a new rate case into effect prior to February 1,
2000. The settlement allows Columbia Transmission to retain the gain from the
1996 sale of base gas from one of its storage fields, as well as certain future
base gas sales. The settlement rates became effective June 1, 1997 and an
after-tax improvement of $12.4 million was recorded in the second quarter of
1997 to reflect the terms of the settlement, including the base gas sale.

Excluded from the settlement is the environmental cost issue which was to be
addressed in the second phase of the proceeding scheduled for hearings during
the fall of 1998. However, as a result of settlement discussions, the active
parties reached an agreement in principle on the overall components of an
environmental settlement. The comprehensive agreement in principle includes such
major components as Columbia Transmission's total allowed recovery of
environmental remediation program costs and the disposition of any proceeds
received by Columbia Transmission from insurance carriers and others. At this
time, the agreement is either supported or not opposed by all but two parties.
Columbia Transmission anticipates filing a stipulation and agreement with the
FERC in the first quarter of 1999.

B. In its September 1993 order on Columbia Transmission's and Columbia Gulf
Transmission Company's (Columbia Gulf) FERC Order No. 636 (Order 636) compliance
filings, the FERC initiated a proceeding concerning Columbia Gulf's
transportation service to Columbia Transmission. It directed Columbia Gulf to
show cause as to why it had not filed for FERC's abandonment authorization to
reduce capacity on its mainline facilities. In a 


                                       50
<PAGE>   51
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


response to the FERC in late 1993, Columbia Gulf asserted that no abandonment
authorization was required. The FERC issued an order on August 8, 1997,
approving a Stipulation and Consent Agreement that required Columbia Gulf to
conduct a 30-day open season on additional firm mainline capacity up to its
certificated design capacity. The open season concluded on December 15, 1997 and
resulted in requested capacity that exceeded Columbia Gulf's certificated level.
On December 24, 1998, the FERC issued an order rejecting all substantial
challenges and reaffirmed the settlement. On January 25, 1999, a petition for
clarification or rehearing and a separate petition for rehearing of the FERC's
December 24, 1998 order were filed. On February 19, 1999, the FERC issued a
tolling order giving itself additional time to act on the January 25, 1999
petitions. In late February 1999, five parties appealed the December 24, 1998
and August 8, 1997 FERC orders to the Court of Appeals for the District of
Columbia.

C. On January 7, 1998, the Public Utility Commission of Ohio (PUCO) approved an
amendment to the 1994 rate case settlement. The amendment establishes a
five-year funding mechanism that enabled Columbia Gas of Ohio, Inc. (Columbia of
Ohio) to expand its Customer CHOICE(SM) transportation program for residential
and small commercial customers statewide in 1998. The funding mechanism
authorizes Columbia of Ohio to use off-system sales, capacity release revenues
and fees collected from marketers to offset the cost of transition capacity that
may be generated by expansion of the Customer CHOICE(SM) program, while
simultaneously providing Columbia of Ohio with an opportunity to retain some of
the capacity release and off-system sales revenue. The amendment also extends by
one year, to January 1, 2000, Columbia of Ohio's commitment not to implement any
increase in base rates. The amendment gives Columbia of Ohio the responsibility
to manage the transition pipeline capacity costs that will arise as residential
and small commercial customers elect to acquire the commodity directly from
marketers participating in the Customer CHOICE(SM) program, and revenue streams
from a number of sources including off-system sales and capacity releases with
which to manage this responsibility. Columbia of Ohio has accepted the risk for
up to 11% of the transition capacity costs to the extent these costs exceed the
revenue streams available to offset them. However, if after the conclusion of
the five-year program the revenues from these sources more than offset the
transition capacity costs, then customers and Columbia of Ohio will share the
credit balance, 75% to the customers and 25% to Columbia of Ohio. In June 1998,
Columbia of Ohio received approval from the PUCO to extend its Customer
CHOICE(SM) program to all of its nearly 1.3 million customers.

3. STOCK SPLIT EFFECTED IN THE FORM OF A STOCK DIVIDEND

On May 20, 1998, Columbia's board of directors approved a three-for-two common
stock split, effected in the form of a 50% stock dividend (stock split), on June
15, 1998, payable to shareholders of record as of June 1, 1998. In connection
with the stock split, 27.8 million shares were issued on June 15, 1998, and
$277.9 million was transferred to common stock from retained earnings. The value
of fractional shares resulting from the stock split was determined at the
closing price on June 1, 1998, and $0.6 million was paid in cash to the
shareholders for fractional-share interests. All references in the financial
statements and notes to the number of common shares outstanding and per-share
amounts, except where otherwise noted, reflect the retroactive effect of the
stock split.

4. RESTRUCTURING ACTIVITIES

In 1996, Columbia's subsidiaries completed a top-down review of their management
structure and operations in an effort to streamline their organizations and
improve customer service. The studies examined all aspects of Columbia's
operations including the configuration and location of its management.

The transmission subsidiaries' restructuring project focused on all processes
within the companies' operations. These efforts resulted in streamlined business
functions, improved organizational structures and reduced staff levels.

The distribution segment initiated a restructuring of its headquarters'
operations as part of its ongoing efforts to provide enhanced customer service
and to achieve greater operating efficiencies. These initiatives, which are
designed to streamline and enhance customer service, are continuing. Additional
studies are underway in all of the distribution segment's service territories
that may affect the field organizations in functions other than customer service
and may result in additional positions being eliminated, with additional expense
being recorded.

In the third quarter of 1996, Columbia Energy Group Service Corporation,
Columbia LNG Corporation and Columbia Electric Corporation (Columbia Electric),
formerly TriStar Ventures Corporation, implemented restructuring programs and
moved their corporate headquarters from Wilmington, Delaware to Northern
Virginia.

As a result of these restructuring programs, it is estimated that 1,412
management, professional, administrative and technical positions will ultimately
be eliminated. In 1996, Columbia recorded a pre-tax charge of $60.9 million in


                                       51
<PAGE>   52
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


operating expense representing severance and related benefit costs, relocation
costs, the establishment of the new corporate center and costs related to the
sale of the former headquarters building. This charge included $52.7 million of
estimated termination benefits. Partially offsetting these charges was a $6
million pre-tax gain on the sale of the former headquarters building. During
1997, Columbia recorded pre-tax charges of $31.1 million in operating expense
representing additional severance and related benefits costs, and additional
relocation costs. This charge included $18.9 million of estimated termination
benefits. As of December 31, 1998, approximately 1,330 employees have been
terminated as a result of these programs and the consolidated balance sheet
reflects an accrual of $4.6 million associated with these restructuring
programs.

5. RISK MANAGEMENT ACTIVITIES

Columbia's gas and power marketing operations utilize futures contracts and
basis swaps to help assure adequate margins on the purchase and resale of
natural gas and electric power. During the fourth quarter of 1998, certain
unusual trading activity in Columbia's gas marketing operations resulted in a
loss. Consistent with generally accepted accounting principles, Columbia applied
mark-to-market accounting for its physical and financial natural gas positions.
The market value of the open physical and financial positions at December 31,
1998, reflected a loss of approximately $6.5 million, which was recorded by
Columbia.

The fair market value of gas trading assets and liabilities were $176.8 million
and $183.3 million, respectively, at December 31, 1998. The average fair market
value of trading assets and liabilities were $117.9 million and $111.9 million,
respectively, for the quarter ended December 31, 1998. Columbia measures the
market risk in its portfolios on a daily basis and employs multiple risk control
mechanisms including value-at-risk measures. Based on a 95% confidence interval
and a one-day time horizon, the value-at-risk for gas trading financial
instruments was approximately $1.8 million as of December 31, 1998.

During the first three quarters of 1998, $15.1 million of losses were recognized
in operating income on the settlement of natural gas option and swap contracts
qualifying for hedge accounting, by the gas marketing subsidiary. These losses
were offset by amounts realized from the sale of the underlying products.

At December 31, 1998, there were 481 net future equivalent contracts to sell
electric power maturing from January 1999 to September 1999 representing a
notional quantity amounting to 354 Gigawatt hours. A total of $0.8 million of
unrealized losses have been deferred on the consolidated balance sheet with
respect to these open contracts. These unrealized losses are largely offset by
gains, which will be realized when the electricity is sold. Based on a 95%
confidence interval and a one-day time horizon, the value-at-risk for the
electric power instruments was approximately $0.4 million as of December 31,
1998. During the year ended December 31, 1998, $0.3 million of losses were
recognized in operating income on the settlement of electric power futures.

Columbia's exploration and production subsidiary hedged a portion of its gas
production that was subject to price volatility through a gas marketing
affiliate. The gas marketing affiliate, in turn, as part of its normal course of
business, hedged these positions in the marketplace. At December 31, 1998, there
were 6,896 open contracts representing a notional quantity amounting to 16.4 Bcf
of commodity contracts and 44.1 Bcf of basis contracts for natural gas
production through October 1999 at a combined average price of $2.79 per Mcf. A
total of $9.1 million of unrealized gains have been deferred on the consolidated
balance sheet with respect to these open contracts. During the year ended
December 31, 1998, $ 11.0 million of gains were realized on contracts settled.
At December 31, 1997, there were 5,443 open contracts representing a notional
quantity amounting to 24.7 Bcf of commodity contracts and 23.0 Bcf of basis
contracts for natural gas production through November 1998 at a combined average
price of $3.02 per Mcf. A total of $8.1 million of unrealized gains have been
deferred on the consolidated balance sheet with respect to these open contracts.
During the year ended December 31, 1997, $4.8 million of losses were realized on
contracts settled.

Columbia's propane subsidiary hedges a portion of its inventory at the time of
purchase against the risk of decreasing prices. At December 31, 1998, there were
620 open contracts through March 1999 representing a notional quantity amounting
to 26.0 million gallons of propane. A total of $0.4 million of unrealized losses
have been deferred on the consolidated balance sheet with respect to these open
contracts. During the year ended December 31, 1998, $1.0 million of losses were
realized on contracts settled. At December 31, 1997, there were 200 open
contracts through February 1998 representing a notional quantity amounting to
8.4 million gallons of propane. No unrealized gains or losses were deferred on
the consolidated balance sheet with respect to these open contracts. During the
year ended December 31, 1997, $0.4 million of gains were realized on contracts
settled.


                                       52
<PAGE>   53
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


6. NEW ACCOUNTING STANDARDS

A. In February 1998, the Financial Accounting Standards Board issued Statement
of Financial Accounting Standards No. 132, "Employees' Disclosures about
Pensions and Other Postretirement Benefits" (SFAS No. 132). This statement
revises disclosures about pension and other postretirement benefit plans. It
does not change the measurement or recognition of the costs of those plans. The
disclosures required by this statement are reflected in the December 31, 1998
financial statements. As required by SFAS No. 132, prior periods presented are
restated for comparative purposes (See Note 8).

B. In June 1998, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards No. 133, "Accounting for Derivative Instruments
and Hedging Activities" (SFAS No. 133). This statement establishes accounting
and reporting standards for derivative instruments, including certain derivative
instruments embedded in other contracts, (collectively referred to as
derivatives) and for hedging activities. SFAS No. 133 requires an entity to
recognize all derivatives as either assets or liabilities in the balance sheet
and measure those instruments at fair value. If certain conditions are met, a
derivative may be specifically designated as (a) a hedge of the exposure to
changes in the fair value of a recognized asset or liability or an unrecognized
firm commitment, (b) a hedge of the exposure to variable cash flows of a
forecasted transaction, or (c) a hedge of the foreign currency exposure of a net
investment in a foreign-currency-denominated forecasted transaction. The
accounting for changes in the fair value of a derivative depends on the intended
use of the derivative and resulting designation. This statement is effective
January 1, 2000. Columbia does not anticipate that the adoption of this
statement will have a significant impact on the consolidated financial
statements.

C. In November 1998, the Financial Accounting Standards Board Emerging Issues
Task Force reached a consensus in Issue No. 98-10, "Accounting for Contracts
Involved in Energy Trading and Risk Management Activities" (EITF 98-10). This
issue provides guidance regarding the accounting for energy trading contracts.
This consensus should be applied to financial statements issued for fiscal years
beginning after December 15, 1998. The application of EITF 98-10 will not have a
significant impact on the consolidated financial statements as the gas marketing
affiliate commenced marking its physical and financial gas transactions to
market during the fourth quarter of 1998.


                                       53
<PAGE>   54
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


7. INCOME TAXES

The components of income tax expense are as follows:

<TABLE>
<CAPTION>
Year Ended December 31, ($ in millions)           1998        1997        1996
- --------------------------------------------------------------------------------
<S>                                               <C>         <C>         <C>
INCOME TAXES
Current
     Federal                                       98.4        82.4        30.4
     State                                          1.8         7.2         7.5
- --------------------------------------------------------------------------------
Total Current                                     100.2        89.6        37.9
- --------------------------------------------------------------------------------
Deferred
     Federal                                       46.3        50.4        64.6
     State                                        (13.2)      (19.6)       14.9
- --------------------------------------------------------------------------------
Total Deferred                                     33.1        30.8        79.5
- --------------------------------------------------------------------------------
Deferred Investment Credits                        (1.5)       (1.5)       (1.5)
- --------------------------------------------------------------------------------
TOTAL INCOME TAXES                                131.8       118.9       115.9
- --------------------------------------------------------------------------------
</TABLE>

Total income taxes are different from the amount that would be computed by
applying the statutory Federal income tax rate to book income before income tax.
The major reasons for this difference are as follows:

<TABLE>
<CAPTION>
Year Ended December 31, ($ in millions)                             1998                   1997                   1996
- -----------------------------------------------------------------------------------------------------------------------------
<S>                                                           <C>         <C>        <C>         <C>        <C>         <C>
Book income before income taxes                               401.0                  392.2                  337.5
Tax expense at statutory Federal income tax rate              140.4       35.0%      137.3       35.0%      118.1       35.0%
Increases (reductions) in taxes resulting from:
  State income taxes, net of Federal income tax benefit        (7.4)      (1.8)       (8.1)      (2.1)       16.7        4.9
   Estimated non-deductible expenses                            1.6        0.4         0.7        0.2         0.9        0.3
   Effect of change in deferred taxes previously provided       1.5        0.4        (1.9)      (0.5)       (4.0)      (1.2)
   Adjustment to prior year's tax provision
     due to pending settlement                                  0.7        0.2        (3.2)      (0.8)      (11.3)      (3.4)
   Other                                                       (5.0)      (1.3)       (5.9)      (1.5)       (4.5)      (1.3)
- -----------------------------------------------------------------------------------------------------------------------------
INCOME TAXES                                                  131.8       32.9%      118.9       30.3%      115.9       34.3%
- -----------------------------------------------------------------------------------------------------------------------------
</TABLE>


                                       54
<PAGE>   55
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


Deferred income taxes result from temporary differences between the financial
statement carrying amounts and the tax basis of existing assets and liabilities.
The principal components of Columbia's net deferred tax liability are as
follows:

<TABLE>
<CAPTION>
At December 31, ($ in millions)                                1998       1997
- --------------------------------------------------------------------------------
<S>                                                           <C>        <C>
Deferred tax liabilities                                      
     Property basis differences                                688.1      655.3
     Gas purchase costs                                         55.0       52.4
     Partnership deferrals                                      27.8       27.5
     Other                                                      33.1       39.5
- --------------------------------------------------------------------------------
Gross Deferred Tax Liabilities                                 804.0      774.7
- --------------------------------------------------------------------------------
Deferred tax assets                                           
     Estimated supplier obligations                            (28.2)     (28.8)
     Estimated rate refunds                                    (21.8)     (16.8)
     Capitalized inventory overheads                           (22.1)     (26.7)
     Unbilled utility revenue                                  (20.9)     (23.2)
     Benefit plan accruals                                     (16.2)     (37.7)
     Environmental liabilities                                 (10.5)      (8.1)
     Tax loss carryforwards                                    (43.9)     (48.7)
     Deferred revenue                                          (18.4)     (17.5)
     Other                                                     (43.3)     (32.7)
- --------------------------------------------------------------------------------
Gross Deferred Tax Assets                                     (225.3)    (240.2)
- --------------------------------------------------------------------------------
Deferred Tax Asset Valuation Allowance                          31.3       34.4
- --------------------------------------------------------------------------------
NET DEFERRED TAX LIABILITY*                                    610.0      568.9
- --------------------------------------------------------------------------------
</TABLE>

*     Includes net current deferred tax assets of $45.3 million and $49.5
      million reflected in Current Assets for 1998 and 1997, respectively.

As reflected by the valuation allowance in the table above, Columbia had
potential tax benefits of $31.3 million and $34.4 million at December 31, 1998
and 1997, respectively, which were not recognized in the statements of
consolidated income when generated. These benefits resulted from state income
tax operating loss carryforwards which are available to reduce future tax
liabilities. Management believes there is a risk that certain of these
carryforwards may expire unused and therefore, an asset has not been recorded
for such future benefits. The expiration of the tax loss carryforward benefits,
net of federal taxes, in 1999 is $1.9 million, in 2000 is $1.2 million, in 2001
is $0.4 million, in 2002 is $0.1 million, in 2003 is $0.2 million and beyond is
$40.1 million

8. PENSION AND OTHER POSTRETIREMENT BENEFITS

Columbia has a noncontributory, qualified defined benefit pension plan covering
essentially all employees. Benefits are based primarily on years of credited
service and employees' highest three-year average annual compensation in the
final five years of service. Columbia's funding policy complies with Federal law
and tax regulations. In addition, Columbia has a nonqualified pension plan that
provides benefits to some employees in excess of the qualified plan's Federal
tax limits. Columbia also provides medical coverage and life insurance to
retirees. Essentially all active employees are eligible for these benefits upon
retirement after completing ten consecutive years of service after age 45.
Normally, spouses and dependents of retirees are also eligible for medical
benefits. Columbia is reflecting the information presented below as of September
30, rather than December 31. The effect of utilizing September 30, rather than
December 31, is not significant.


                                       55
<PAGE>   56
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


The following tables provides a reconciliation of the plans' funded status and
amounts reflected in Columbia's balance sheet at December 31:


<TABLE>
<CAPTION>
                                                        PENSION BENEFITS             OTHER BENEFITS
                                                     ---------------------       ---------------------  
($ in millions)                                        1998          1997          1998          1997
- ------------------------------------------------------------------------------------------------------
<S>                                                  <C>           <C>           <C>           <C>
CHANGE IN BENEFIT OBLIGATION
Benefit obligation at beginning of year                888.9         869.9         309.8         287.2
Service cost                                            31.3          28.7          13.0          11.2
Interest cost                                           64.7          67.6          23.4          23.1
Plan participants' contributions                          --            --           2.7            --
Plan amendments                                           --            --          (2.2)           --
Actuarial gain                                          56.0          35.4           6.2           7.5
Settlements                                               --            --        (130.3)           --
Actual expense paid                                     (5.2)         (6.1)           --            --
Benefits paid                                          (88.9)       (106.6)        (23.7)        (19.2)
- ------------------------------------------------------------------------------------------------------
Benefit obligation at end of year                      946.8         888.9         198.9         309.8
- ------------------------------------------------------------------------------------------------------
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year       1,164.6       1,033.9         242.9         179.6
Actual return on plan assets                            20.8         243.1          11.2          48.3
Columbia contributions                                    --            --          32.4          34.2
Plan participants' contributions                          --            --           2.8            --
Settlements                                               --            --        (146.9)           --
Actual expense paid                                     (5.2)         (6.1)         (1.7)           --
Benefits paid                                          (88.7)       (106.3)        (23.7)        (19.2)
- ------------------------------------------------------------------------------------------------------
Fair value of plan assets at end of year             1,091.5       1,164.6         117.0         242.9
- ------------------------------------------------------------------------------------------------------
Funded status of plan at end of year                   144.7         275.7         (81.9)        (66.9)
Unrecognized actuarial net gain                       (237.8)       (390.2)        (41.5)       (129.9)
Unrecognized prior service cost                         45.1          48.9          (2.2)           --
Unrecognized transition obligation                       4.6           5.8            --            --
Fourth quarter contributions                              --            --           4.5           7.4
- ------------------------------------------------------------------------------------------------------
ACCRUED BENEFIT COST                                   (43.4)        (59.8)       (121.1)       (189.4)
- ------------------------------------------------------------------------------------------------------

<CAPTION>
                                                        PENSION BENEFITS             OTHER BENEFITS
                                                     ---------------------       ---------------------  
                                                        1998          1997          1998          1997
- ------------------------------------------------------------------------------------------------------
<S>                                                  <C>           <C>           <C>           <C>
WEIGHTED-AVERAGE ASSUMPTIONS AS OF
  SEPTEMBER 30,
Discount rate assumption                                6.75%         7.50%         6.75%         7.50%
Compensation growth rate assumption                     4.40%         4.30%         4.40%         4.30%
Medical cost trend assumption                             --            --          5.50%         5.50%
Assets earnings rate assumption                         9.00%         9.00%         9.00%*        9.00%*
- ------------------------------------------------------------------------------------------------------
</TABLE>

*     One of the several established medical trusts is subject to taxation which
      results in an after-tax asset earnings rate that is less than 9.00%


                                       56
<PAGE>   57
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


The following table provides the components of the plans expense for each of the
three years:

<TABLE>
<CAPTION>
                                                PENSION BENEFITS                  OTHER BENEFITS
                                          ----------------------------     ----------------------------
($ in millions)                            1998       1997       1996       1998       1997       1996
- -------------------------------------------------------------------------------------------------------
<S>                                       <C>        <C>        <C>        <C>        <C>        <C>
NET PERIODIC COST
Service cost                               31.3       28.7       35.0       13.0       11.2       13.8
Interest cost                              64.7       67.6       70.7       23.5       23.1       22.4
Expected return on assets                 (99.7)     (88.2)     (90.3)     (18.3)     (13.1)     (12.0)
Amortization of transition obligation       1.2        1.2        1.2         --         --         --
Recognized gain                           (17.5)     (11.3)      (2.0)     (10.3)      (9.6)      (5.9)
Prior service cost amortization             3.7        3.7        4.1         --         --         --
Settlement gain                              --         --         --      (46.6)        --         --
- -------------------------------------------------------------------------------------------------------
NET PERIODIC BENEFITS COST (BENEFIT)      (16.3)       1.7       18.7      (38.7)      11.6       18.3
- -------------------------------------------------------------------------------------------------------
</TABLE>

Assumed health care cost trend rates have a significant effect on the amounts
reported for the health care plans. A one-percentage-point change in assumed
health care cost trend rates would have the following effects:

<TABLE>
<CAPTION>
                                                                  1% point   1% point
                                                                  increase   decrease
- -------------------------------------------------------------------------------------
<S>                                                               <C>        <C>     
Effect on service and interest components of net periodic cost    $   2.8    $  (2.6)

Effect on accumulated postretirement benefit obligation           $  14.9    $ (14.5)
- -------------------------------------------------------------------------------------
</TABLE>

In March 1998, trusts established by Columbia purchased insurance policies that
provide both medical and life insurance with respect to liabilities to a
selected class of current retirees. This resulted in a pre-tax gain in the
amount of $46.6 million. This gain is reflected in the financial statements as a
$25.4 million reduction to benefits expense, and a $21.2 million liability of
certain rate-regulated companies.

9. LONG-TERM INCENTIVE PLAN

On April 26, 1996, shareholders approved a new Long-Term Incentive Plan (New
LTIP). The New LTIP which is effective for ten years, beginning February 21,
1996, provides for the granting of nonqualified stock options and incentive
stock options, contingent stock awards, stock appreciation rights and restricted
stock awards to officers and key employees. The New LTIP also provides for the
granting of nonqualified stock options to outside directors. A total of
3,000,000 shares of Columbia's authorized common stock is available under the
New LTIP's provisions.

On April 26, 1996, shareholders also approved an incentive compensation plan for
outside directors under which they may receive benefits in lieu of a retirement
plan and defer current compensation in the form of phantom stock units, which
equates the amounts granted to the directors with the performance of Columbia's
stock.

Columbia's Long-Term Incentive Plan (LTIP), in effect from 1985 through 1995,
provided for the granting of nonqualified stock options, stock appreciation
rights and contingent stock awards as determined by the Compensation Committee
of the Board of Directors. That committee also had the right to modify any
outstanding award. A total of 1,500,000 shares of Columbia's authorized common
stock was initially reserved for issuance under the LTIP's provisions.

Stock appreciation rights, which were granted in connection with certain
nonqualified stock options, entitle the holders to receive stock, cash or a
combination thereof equal to the excess market value over the grant price. Stock
options and related stock appreciation rights granted under the LTIP generally
have a maximum term of ten years and vest over two to four years.


                                       57
<PAGE>   58
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


Transactions for the three years ended December 31, 1998, are as follows:

<TABLE>
<CAPTION>
                                                          Options
                                                -----------------------------
                                                 Without Stock   With Stock          Options
                                                 Appreciation   Appreciation          Price
                                                    Rights         Rights             Range
- --------------------------------------------------------------------------------------------------
<S>                                             <C>             <C>            <C>
Outstanding  at December 31, 1995                   524,320        150,050          $28.99-$46.68
     Granted                                        100,000             --               $48.6875
     Exercised                                     (209,625)       (66,860)         $28.99-$46.68
     Forfeited                                       (9,020)        (7,260)         $34.30-$46.68
- --------------------------------------------------------------------------------------------------
Outstanding at December 31, 1996                    405,675         75,930        $28.99-$48.6875
     Granted                                      1,133,350             --       $58.375-$71.0938
     Exercised                                     (183,138)       (48,790)       $28.99-$63.6875
     Forfeited                                      (41,962)        (3,240)       $34.30-$63.6875
- --------------------------------------------------------------------------------------------------
Outstanding at December 31, 1997                  1,313,925         23,900        $28.99-$71.0938
     Granted                                        853,300             --     $76.15625-$77.5625
     Exercised                                      (92,821)            --        $28.99-$63.6875
     Forfeited                                       (9,000)            --      $58.375-$76.15625
     Adjustment for three-for-two stock split     1,032,700         11,950        $19.33-$51.7083*
     Granted                                         20,800             --        $52.875-$58.375
     Exercised                                     (114,579)       (26,190)       $19.33-$42.4583
     Forfeited                                      (19,050)            --             $ 50.77083
- --------------------------------------------------------------------------------------------------
OUTSTANDING AT DECEMBER 31, 1998                  2,985,275          9,660         $19.33-$58.375
- --------------------------------------------------------------------------------------------------
EXERCISABLE AT DECEMBER 31, 1998                  1,193,300          9,660        $19.33-$51.7083
- --------------------------------------------------------------------------------------------------
</TABLE>

*     Reflects repricing of outstanding stock options for the effect of the
      three-for-two common stock split.

Regarding the stock options granted in 1998 and 1997, such options vest ratably
over three years. Regarding the stock options granted in 1996, 50% of such
options vested in 1996 and the other 50% vested in 1997.

The following table shows the weighted-average option exercise price information
for the three years ended December 31:

<TABLE>
<CAPTION>
                                            1998           1997           1996
- --------------------------------------------------------------------------------
<S>                                       <C>            <C>            <C>     
Outstanding at January 1                  $  59.37       $  42.88       $  41.31
Granted during the year                      75.69          63.40          48.69
Exercised during the year                    43.97          44.31          41.07
Forfeited during the year                    55.49          62.01          44.15
OUTSTANDING AT DECEMBER 31                   44.79          59.37          42.88
EXERCISABLE AT DECEMBER 31                   39.56          54.70          42.21
- --------------------------------------------------------------------------------
</TABLE>

In 1996, contingent stock awards totaling 1,500 shares were granted and issued
to one key executive. There were no contingent stock awards granted in 1997 or
1998. Restricted stock awards totaling 29,785 shares were granted to one key
executive in 1996 of which 5,957 shares vested during 1997 and 5,957 shares
vested during 1998.

During 1998, 1997 and 1996, $2.4 million, $3.2 million and $2.1 million were
expensed for the long-term incentive plans, respectively.

Had compensation cost been determined consistent with the provisions of the SFAS
No. 123 fair value method (See Note 1), Columbia's net income would have been
$258.4 million (earnings per share of $3.10 and diluted earnings per share of
$3.09) in 1998 and $266.8 million (earnings per share of $3.21 and diluted
earnings per share of $3.19) in 1997. The effect on Columbia's net come and
earnings per share for 1996 would have been immaterial. The fair value of each
option grant is estimated on the date of grant using the Black-Scholes
option-pricing model with the following assumptions used for grants in 1998,
1997 and 1996: dividend yield of zero percent for 1998, 1997 and 1996 to reflect
dividend equivalents applicable to awards granted; expected volatility ranging
from 14.97% to 17.40% for 1998, 18.41% to 19.29% for 1997 and 20.12% for 1996;
risk-free interest rates ranging from 4.90% to 5.77% for 1998, 5.86% to 6.89%
for 1997 and 6.58% for 1996; and expected lives of seven years. The
weighted-average fair market value of options granted were $17.79, $24.85 and
$19.80 for 1998, 1997 and 1996, respectively.


                                       58
<PAGE>   59
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


10. LONG-TERM DEBT

The long-term debt (exclusive of current maturities) of Columbia and its
subsidiaries is as follows:

<TABLE>
<CAPTION>
At December 31,  ($ in millions)                            1998           1997
- --------------------------------------------------------------------------------
<S>                                                       <C>            <C>
Columbia Energy Group Debentures
   6.39% Series A due November 28, 2000                     311.0          311.0
   6.61% Series B due November 28, 2002                     281.5          281.5
   6.80% Series C due November 28, 2005                     281.5          281.5
   7.05% Series D due November 28, 2007                     281.5          281.5
   7.32% Series E due November 28, 2010                     281.5          281.5
   7.42% Series F due November 28, 2015                     281.5          281.5
   7.62% Series G due November 28, 2025                     281.5          281.5
- --------------------------------------------------------------------------------
Total Debentures                                          2,000.0        2,000.0

Subsidiary Debt:
Capitalized lease obligations                                 3.1            2.7
Other                                                          --            0.8
- --------------------------------------------------------------------------------
TOTAL LONG-TERM DEBT                                      2,003.1        2,003.5
- --------------------------------------------------------------------------------
</TABLE>

During 1998, Columbia entered into interest rate swap agreements to modify the
interest characteristics of its outstanding long-term debt. At December 31,
1998, Columbia has outstanding four interest rate swap agreements effective
through November 28, 2002, on $200 million notional amounts of its 6.61% Series
B Debentures due November 28, 2002. In addition, Columbia has outstanding an
interest rate swap agreement effective through November 28, 2005, on a $100
million notional amount of its 6.80% Series C Debentures due November 28, 2005.
Under the terms of the agreements, Columbia pays interest based on a floating
rate index and receives interest based on a fixed rate. The effect of these
agreements is to modify the interest rate characterization of a portion of
Columbia's long-term debt from fixed to variable. The effect of these interest
rate swaps on interest expense at December 31, 1998, was immaterial.

The aggregate maturities of long-term debt and capitalized lease obligations
during the next five years are as follows:

<TABLE>
<CAPTION>
($ in millions)
- --------------------------------------------------------------------------------
<S>                                                                        <C>
1999                                                                         0.3
2000                                                                       311.2
2001                                                                         0.2
2002                                                                       281.8
2003                                                                         0.3
- --------------------------------------------------------------------------------
</TABLE>

11. SHORT-TERM DEBT AND CREDIT FACILITIES

In March 1998, Columbia established two new unsecured bank revolving credit
facilities that total $1.35 billion (New Credit Facilities) to replace the $1
billion five-year revolving credit agreement entered into by Columbia in
November 1995. The New Credit Facilities consist of a $900 million five-year
revolving credit facility and a $450 million 364-day revolving credit facility
with a one-year term loan option. The five-year facility provides for the
issuance of up to $300 million of letters of credit. Interest rates on
borrowings under the New Credit Facilities are based upon the London Interbank
Offered Rate or Citibank's publicly announced "base rate." Facility fee payments
are based upon Columbia's public debt ratings. At Columbia's current rating, the
facility fee charged on the $900 million credit facility is 0.09% and on the
$450 million credit facility is 0.06%. The New Credit Facilities contain certain
covenants that must be met to borrow funds including restrictions on the
incurrence of liens and a maximum leverage ratio. Compensating balances are not
required.

At December 31, 1998, Columbia had no borrowings outstanding under the New
Credit Facilities. The maximum indebtedness outstanding during the year occurred
on January 1, 1998, in the amount of $120 million at an average interest rate of
6.17%.


                                       59
<PAGE>   60
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


As of December 31, 1998, Columbia had $44.4 million of letters of credit
outstanding under the New Credit Facilities. Fees for letters of credit issued
are calculated at rates that are based on Columbia's public debt rating plus a
commission of 0.125% to the issuing bank. In addition, Columbia had a $75
million letter of credit outstanding at December 31, 1998 and December 31, 1997,
as a guarantee of certain transactions of its wholly owned marketing affiliate.
Fees for the letter of credit issued were at a rate of 0.35%.

Columbia has an $850 million commercial paper program authorized and rated by
the rating agencies. The commercial paper program is supported by the New Credit
Facilities. At December 31, 1998, Columbia had commercial paper outstanding of
$144.8 million (net of discount) at a weighted-average interest rate of 6.12%.
The maximum commercial paper indebtedness outstanding during the year occurred
on February 6, 1998, in the amount $237.1 million at an average interest rate of
5.72%. At December 31, 1997, Columbia had commercial paper outstanding of $208.1
million (net of discount) at a weighted-average interest rate of 6.42%

In November 1995, Columbia entered into an unsecured $1 billion five-year
revolving credit agreement (Credit Facility). The Credit Facility was used to
support outstanding commercial paper and to meet other short-term requirements.
Interest rates on borrowings were based upon the London Interbank Offered Rate,
Certificate of Deposit rates or other short-term interest rates including a
facility fee on the commitment amount at a rate based on Columbia's public debt
rating. The facility fee rate as of December 31, 1997 was 0.11%.

At December 31, 1997, Columbia had outstanding $120 million under the Credit
Facility at an average interest rate of 6.17%. Columbia had $42.7 million of
letters of credit outstanding at December 31, 1997 under the Credit Facility.
Fees for letters of credit issued under the Credit Facility were calculated at
rates based on Columbia's public debt rating plus a commission of 0.125% to the
issuing bank.

At December 31, 1998, approximately $7.6 million of investments were pledged as
collateral on outstanding letters of credit related to Columbia's wholly owned
insurance company.

12. FAIR VALUE OF FINANCIAL INSTRUMENTS

Statement of Financial Accounting Standards No. 107, "Disclosures about Fair
Value of Financial Instruments," requires all entities to disclose the fair
value of financial instruments, both assets and liabilities, recognized and not
recognized in the consolidated balance sheets, for which it is practicable to
estimate a fair value. For purposes of this disclosure, the fair value of a
financial instrument is the amount at which the instrument could be exchanged in
a current transaction between willing parties, other than in a forced or
liquidation sale. Fair value may be based on quoted market prices for the same
or similar financial instruments or on valuation techniques, such as the present
value of estimated future cash flows using a discount rate commensurate with the
risks involved.

As cash and temporary cash investments, current receivables, current payables,
and certain other short-term financial instruments are all short-term in nature,
their carrying amount approximates fair value. Columbia utilizes standby letters
of credit (See Note 11) and does not believe it is practicable to estimate their
fair value.

The following methods and assumptions were used to estimate the fair value of
each class of financial instruments for which it is practicable to estimate that
value:

LONG-TERM INVESTMENTS

Long-term investments include loans receivable ($3.3 million for 1998 and $3.7
million for 1997) whose estimated fair values are based on the present value of
estimated future cash flows using an estimated rate for similar loans. Long-term
investments also include pledged assets ($11.8 million for 1998 and $7.5 million
for 1997), whose estimated fair value is based on the trading value provided by
a financial institution. The financial instruments included in long-term
investments are primarily reflected in Investments and Other Assets on the
consolidated balance sheets. Long-term investments for which it is practicable
to estimate fair value had carrying amounts of $15.1 million and $11.2 million,
and estimated fair values of $14.7 million and $10.8 million at December 31,
1998 and 1997, respectively. There are no long-term investments for which it is
not practicable to estimate fair value at December 31, 1998 and 1997.

LONG-TERM DEBT

The estimated fair value of Columbia's debentures, including accrued interest,
is based on estimates provided by brokers. Long-term debt of $2,012.9 million
and $2,012.9 million at December 31, 1998 and 1997, have estimated fair values
of $2,088.1 million and $2,051.6 million, respectively.


                                       60
<PAGE>   61
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


13. OTHER COMMITMENTS AND CONTINGENCIES

A. EMERGENCE FROM CHAPTER 11 OF THE BANKRUPTCY CODE. On November 28, 1995,
Columbia and its wholly owned subsidiary, Columbia Transmission emerged from
Chapter 11 protection of the Federal Bankruptcy Code under the jurisdiction of
the United States Bankruptcy Court for the District of Delaware (Bankruptcy
Court). Both Columbia and Columbia Transmission had operated under Chapter 11
protection since July 31, 1991. In settlement of its prepetition obligations,
Columbia distributed approximately $3.6 billion to its creditors, which included
$2.3 billion in payment of Columbia's prepetition debt and approximately $1
billion of interest on that debt. Certain residual unresolved bankruptcy-related
matters are still within the jurisdiction of the Bankruptcy Court. The final
resolution of these issues is not expected to have a significant impact on
Columbia's consolidated financial results.

B. CAPITAL EXPENDITURES. Capital expenditures for 1999 are currently estimated
at $650 million. Of this amount, $237 million is for transmission and storage
operations, $152 million for distribution operations, $104 million for
exploration and production operations, $20 million for marketing operations,
$129 million for propane, power generation and LNG operations and $8 million for
corporate.

C. OTHER LEGAL PROCEEDINGS. In the normal course of its business, Columbia and
its subsidiaries have been named as defendants in various legal proceedings. In
the opinion of management, the ultimate disposition of these currently asserted
claims will not have a material adverse impact on Columbia's consolidated
financial position or results of operations.

D. ASSETS UNDER LIEN. Substantially all of Columbia Transmission's properties
have been pledged to Columbia as security for debt owed by Columbia Transmission
to Columbia.

Columbia Electric holds indirectly through various subsidiaries, both general
and limited partnership interests in the following electric power generation
projects:

Pedricktown Cogeneration Limited Partnership and Vineland Cogeneration Limited
Partnership (the "Partnerships") own and operate project-financed non-utility
power generation facilities in New Jersey. The assets of the Partnerships,
including plant facilities and contract rights, have been pledged as collateral
for loans to a bank syndicate in the case of Pedricktown, or to an indenture
trustee for the benefit of certain bondholders in the case of Vineland.

Gregory Power Partners owns a 550 megawatt equivalent electric power generation
plant that is currently under construction in Gregory, Texas. The assets and
contract rights have been pledged as collateral for the construction loan.

Columbia Electric's investment in these partnerships, as of December 31, 1998,
amounted to $18.6 million.

E. INTERNAL REVENUE SERVICE (IRS) AUDIT. The field audit of Columbia's 1995
federal income tax return has been finalized and discussions on all unagreed
issues have begun. The audit of tax years 1996 and 1997 began in February, 1999.
Management believes adequate reserves have been established for issues related
to these returns.

F. OPERATING LEASES. Payments made in connection with operating leases are
primarily charged to operation and maintenance expense as incurred. Such amounts
were $63.8 million in 1998, $62.9 million in 1997 and $60.9 million in 1996.

Future minimum rental payments required under operating leases that have initial
or remaining noncancellable lease terms in excess of one year are:

<TABLE>
<CAPTION>
($ in millions)
- --------------------------------------------------------------------------------
<S>                                                                        <C> 
1999                                                                        35.5
2000                                                                        31.9
2001                                                                        28.1
2002                                                                        27.0
2003                                                                        26.6
After                                                                      187.4
- --------------------------------------------------------------------------------
</TABLE>


                                       61
<PAGE>   62
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


G. PURCHASE COMMITMENTS. Columbia has service agreements that provide for
pipeline capacity, transportation and storage services. These agreements which
have expiration dates ranging from 2000 to 2017 provide for Columbia to pay
fixed monthly charges. The estimated aggregate amounts of such payments at
December 31, 1998, were:

<TABLE>
<CAPTION>
($ in millions)
- --------------------------------------------------------------------------------
<S>                                                                        <C> 
1999                                                                        60.0
2000                                                                        55.7
2001                                                                        42.5
2002                                                                        39.8
2003                                                                        34.7
After                                                                      138.3
- --------------------------------------------------------------------------------
</TABLE>

Costs incurred under these contracts are recovered under Columbia's regulatory
cost recovery mechanisms.

H. ENVIRONMENTAL MATTERS. Columbia's subsidiaries are subject to extensive
federal, state and local laws and regulations relating to environmental matters.
These laws and regulations, which are constantly changing, require expenditures
for corrective action at various operating facilities, waste disposal sites and
former gas manufacturing sites for conditions resulting from past practices that
have subsequently become subject to environmental regulation.

Columbia's transmission subsidiaries have implemented programs to continually
review compliance with existing environmental standards. In addition, the
transmission subsidiaries continue to review past operational activities and to
formulate remediation programs where necessary.

Columbia Transmission is currently conducting assessment, characterization and
remediation activities at specific sites under a 1995 Environmental Protection
Agency (EPA) Administrative Order by Consent (AOC). The program pursuant to the
AOC covers approximately 240 facilities, approximately 15,000 liquid removal
points, approximately 2,800 mercury measurement stations, and about 3,700
storage wells. As of December 31, 1998, field characterization has been
performed at many of these sites, and site characterization reports and
remediation plans are being prepared for submission to EPA for approval.
Significant remediation has taken place only at mercury measurement stations.
Only those site investigation, characterization and remediation costs currently
known and determinable can be considered "probable and reasonably estimable"
under Statement of Financial Accounting Standards No. 5, "Accounting for
Contingencies" (SFAS No. 5). As costs become probable and reasonably estimable,
the associated reserves will be adjusted as appropriate. Columbia Transmission
is unable, at this time, to accurately estimate the time frame and potential
costs of the entire program. Management expects that as additional work is
performed and more facts become available, it will be able to develop a probable
and reasonable estimate for the entire program or a major portion thereof
consistent with U.S. Securities and Exchange Commission's Staff Accounting
Bulletin No. 92, SFAS No. 5, and American Institute of Certified Public
Accountants Statement of Position 96-1.

As a result of 1998 activities, Columbia Transmission recorded an additional
liability of $28.8 million. Actual expenditures of approximately $16 million
during 1998 charged to the liability resulted in a remaining liability of $138.2
million. Columbia Transmission's environmental cash expenditures are expected to
be approximately $18 million in 1999 and up to $20 million annually until the
AOC is satisfied. These expenditures will be charged against the previously
recorded liability. Consistent with Statement of Financial Accounting Standards
No. 71, a regulatory asset has been recorded to the extent environmental
expenditures are expected to be recovered through rates. Management does not
believe that Columbia Transmission's environmental expenditures will have a
material adverse effect on its operations, liquidity or financial position,
based on known facts and existing laws and regulations and the long time period
over which expenditures will be made.

In addition, predecessor companies of Columbia Transmission may have been
involved in the operation of manufactured gas plants. When such plants were
abandoned, material used and created in the process was sometimes buried at the
site. As of the date of this report, Columbia Transmission is unable to
determine if it will become liable for any characterization or remediation costs
at such sites.

Distribution's primary environmental issues relate to 15 former manufactured gas
plant sites. Investigations or remedial activities are currently underway at
seven sites and have been completed at one site. Additional site investigations
may be required at some of the remaining sites. To the extent Distribution's
site investigations have been conducted, remediation plans developed and any
responsibility for remediation action established, the appropriate liabilities
have been recorded. Regulatory assets have also been recorded for a majority of
these costs as rate recovery has been authorized or is anticipated.


                                       62
<PAGE>   63
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


The eventual total cost of full future environmental compliance for Columbia is
difficult to estimate due to, among other things: (1) the possibility of as yet
unknown contamination, (2) the possible effect of future legislation and new
environmental agency rules, (3) the possibility of future litigation, (4) the
possibility of future designations as a potential responsible party by the EPA
and the difficulty of determining liability, if any, in proportion to other
responsible parties, (5) possible insurance and rate recoveries, and (6) the
effect of possible technological changes relating to future remediation.
However, reserves have been established based on information currently available
which resulted in a total recorded net liability of approximately $140.9 million
for Columbia at December 31, 1998. As new issues are identified, additional
liabilities will be recorded.

It is management's continued intent to address environmental issues in
cooperation with regulatory authorities in such a manner as to achieve mutually
acceptable compliance plans. However, there can be no assurance that fines and
penalties will not be incurred. Management expects most environmental assessment
and remediation costs to be recoverable through rates.

I. DISCUSSIONS WITH FERC. The transmission and storage subsidiaries are in
confidential and informal discussions with the staff of the FERC concerning the
scope of authorizations for certain past transactions under the relevant filed
tariffs. The transmission and storage subsidiaries have initiated these
discussions with the FERC. Because these discussions are in a very preliminary
stage, management is unable to reasonably estimate the amount that will have to
be paid pursuant to reimbursement or other remedies.


14. INTEREST INCOME AND OTHER, NET

<TABLE>
<CAPTION>
Year Ended December 3l, ($ in millions)               1998       1997       1996
- --------------------------------------------------------------------------------
<S>                                                   <C>        <C>        <C> 
Interest income                                       13.6       21.0       13.4
Miscellaneous                                         (0.2)      19.4       12.7
- --------------------------------------------------------------------------------
TOTAL INTEREST INCOME AND OTHER, NET                  13.4       40.4       26.1
- --------------------------------------------------------------------------------
</TABLE>


15. INTEREST EXPENSE AND RELATED CHARGES

<TABLE>
<CAPTION>
Year Ended December 31, ($ in millions)               1998       1997       1996
- --------------------------------------------------------------------------------
<S>                                                  <C>        <C>        <C>  
Interest on debentures                               140.4      140.4      140.4
Interest on short-term debt                           10.9        8.1       11.7
Discount on prepayment transactions                    7.8        0.1         --
Interest on rate refunds                               2.3        3.4        3.9
Interest on prior years' taxes                        (6.3)       9.1        8.3
Allowance for borrowed funds used
   and interest during construction                   (2.7)      (3.5)       2.5
- --------------------------------------------------------------------------------
TOTAL INTEREST EXPENSE AND RELATED CHARGES           152.4      157.6      166.8
- --------------------------------------------------------------------------------
</TABLE>


                                       63
<PAGE>   64
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


16. BUSINESS SEGMENT INFORMATION

Columbia is a registered holding company under the Public Utility Holding
Company Act of 1935, as amended and derives substantially all of its revenues
and earnings from the operating results of its 18 direct subsidiaries. Effective
June 30, 1998, in accordance with generally accepted accounting principles,
Columbia revised the presentation of its business segments. Columbia's
operations are divided into five primary business segments. The transmission and
storage segment offers transportation and storage services for local
distribution companies, marketers and industrial and commercial customers
located in northeastern, midatlantic, midwestern and southern states and the
District of Columbia. The distribution segment provides natural gas service and
transportation for residential, commercial and industrial customers in Ohio,
Pennsylvania, Virginia, Kentucky and Maryland. The exploration and production
segment explores for, develops, produces and markets gas and oil in the United
States and in Canada. The marketing segment provides gas and electricity supply,
fuel management and transportation-related services to a diverse customer base
including cogenerators, local distribution companies, industrial plants,
commercial businesses, joint marketing partners and residential customers. The
propane, power generation and LNG segment includes the sale of propane at
wholesale and retail to customers in eight states, participation in natural gas
fueled electric generation projects and peaking services.

The following tables provide information concerning Columbia's major business
segments. Revenues include intersegment sales to affiliated subsidiaries, which
are eliminated when consolidated. Affiliated sales are recognized on the basis
of prevailing market or regulated prices. Operating income is derived from
revenues and expenses directly associated with each segment.


<TABLE>
<CAPTION>
($ in millions)                                   1998        1997        1996
- --------------------------------------------------------------------------------
<S>                                             <C>         <C>         <C>
REVENUES
       Transmission and Storage
            Unaffiliated                          523.0       505.7       450.4
            Intersegment                          315.7       332.9       354.6
- --------------------------------------------------------------------------------
            TOTAL                                 838.7       838.6       805.0
- --------------------------------------------------------------------------------
       Distribution
            Unaffiliated                        1,843.3     2,283.6     2,120.4
            Intersegment                           26.2        12.7         7.3
- --------------------------------------------------------------------------------
            TOTAL                               1,869.5     2,296.3     2,127.7
- --------------------------------------------------------------------------------
       Exploration and Production
            Unaffiliated                           65.2        44.3        45.5
            Intersegment                           62.3        69.0        59.0
- --------------------------------------------------------------------------------
            TOTAL                                 127.5       113.3       104.5
- --------------------------------------------------------------------------------
       Marketing
            Unaffiliated                        4,047.5     2,121.9       645.6
            Intersegment                           24.7        65.1        82.4
- --------------------------------------------------------------------------------
            TOTAL                               4,072.2     2,187.0       728.0
- --------------------------------------------------------------------------------
       Propane, Power Generation and LNG
            Unaffiliated                           89.2        98.3        91.7
            Intersegment                            0.5         2.1         2.5
- --------------------------------------------------------------------------------
            TOTAL                                  89.7       100.4        94.2
- --------------------------------------------------------------------------------
       Adjustments and eliminations
            Unaffiliated                             --        (0.2)        0.4
            Intersegment                         (429.4)     (481.8)     (505.8)
- --------------------------------------------------------------------------------
            TOTAL                                (429.4)     (482.0)     (505.4)
- --------------------------------------------------------------------------------
       CONSOLIDATED                             6,568.2     5,053.6     3,354.0
- --------------------------------------------------------------------------------
</TABLE>


                                       64
<PAGE>   65
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


<TABLE>
<CAPTION>
($ in millions)                                 1998         1997         1996
- --------------------------------------------------------------------------------
<S>                                          <C>          <C>          <C>
OPERATING INCOME (LOSS)
       Transmission and Storage                 326.1        258.3        206.2
       Distribution                             225.8        224.2        226.0
       Exploration and Production                37.2         30.9         30.0
       Marketing                                (59.0)       (13.2)         4.5
       Propane, Power Generation
         and LNG                                 10.7         16.3          9.6
       Corporate                                 (0.8)        (7.1)         1.9
- --------------------------------------------------------------------------------
       CONSOLIDATED                             540.0        509.4        478.2
- --------------------------------------------------------------------------------
DEPRECIATION & DEPLETION
       Transmission and Storage                 101.8        104.3        102.6
       Distribution                              82.2         78.2         74.4
       Exploration and Production                36.5         27.6         28.8
       Marketing                                  4.1          1.6          0.3
       Propane, Power Generation
         and LNG                                  5.1          3.6          2.8
       Corporate                                  5.0          5.5          5.7
       Adjustments and eliminations               0.5          0.5          0.6
- --------------------------------------------------------------------------------
       CONSOLIDATED                             235.2        221.3        215.2
- --------------------------------------------------------------------------------
ASSETS
       Transmission and Storage               2,837.6      2,775.4      2,774.3
       Distribution                           2,629.9      2,753.2      2,648.1
       Exploration and Production               590.9        564.6        511.9
      Marketing                                 778.7        509.4        205.7
       Propane, Power Generation
         and LNG                                193.0        155.7        133.5
       Corporate                              4,298.0      4,221.4      3,924.6
       Adjustments and eliminations          (4,359.4)    (4,367.4)    (4,193.5)
- --------------------------------------------------------------------------------
       CONSOLIDATED                           6,968.7      6,612.3      6,004.6
- --------------------------------------------------------------------------------
CAPITAL EXPENDITURES
       Transmission and Storage                 204.0        244.9        142.7
       Distribution                             151.9        159.5        148.4
       Exploration and Production                75.7        158.7         12.1
       Marketing                                 16.0          5.1          0.8
       Propane, Power Generation
         and LNG                                 20.1          9.9          5.5
       Corporate                                 11.0          5.3          5.3
       Adjustments and eliminations                --        (23.1)          --
- --------------------------------------------------------------------------------
       CONSOLIDATED                             478.7        560.3        314.8
- --------------------------------------------------------------------------------
</TABLE>


                                       65
<PAGE>   66
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


17. QUARTERLY FINANCIAL DATA (UNAUDITED)

Quarterly financial data does not always reveal the trend of Columbia's business
operations due to nonrecurring items and seasonal weather patterns which affect
earnings and related components of net revenues and operating income.

<TABLE>
<CAPTION>
                                                 First        Second         Third     Fourth
($ in millions, except per share data)          Quarter       Quarter       Quarter    Quarter
- ------------------------------------------------------------------------------------------------
<S>                                             <C>           <C>           <C>        <C>
1998
     Net Revenues                                622.5         385.6         350.2      538.8
     Operating Income                            254.2          70.9          54.1      160.8
     Net Income                                  147.5(a)       22.8          11.2       87.7(b)

     Per Share Amounts
         Earnings Per Share of Common Stock       1.77          0.27          0.13       1.05
         Diluted Earnings Per Share of
Common Stock                                      1.77          0.27          0.13       1.05
- ------------------------------------------------------------------------------------------------
1997
     Net Revenues                                628.1         407.1         331.3      549.0
     Operating Income                            256.6          84.3          29.7      138.8
     Net Income                                  162.7(c)       34.9(d)        0.1       75.6(e)

     Per Share Amounts
         Earnings Per Share of Common Stock       1.96          0.42            --       0.91
         Diluted Earnings Per Share of
Common Stock                                      1.96          0.42            --       0.90
</TABLE>

(a)   Includes $8.7 million from the sale of base gas, $16.5 million gain on
      settlement of postretirement benefit costs and a $10 million benefit from
      state tax planning initiatives.

(b)   Includes $10.6 million reduction on the marketing segment for a provision
      for amounts that presently do not have adequate third party documentation.

(c)   Includes $12.8 million reduction in state income tax expense and $5.5
      million gain on deactivation of a storage field.

(d)   Includes $12.4 million from the sale of base gas.

(e)   Includes the net income effect of $6.0 million for the sale of coal
      assets.

18. EXPLORATION AND PRODUCTION ACTIVITIES (UNAUDITED)

During the first quarter of 1998, Columbia Energy Resources, Inc. (Columbia
Resources) purchased wells and undeveloped property in Ontario, Canada. In June
1998, Columbia Resources further broadened its Canadian operations by entering
into a joint venture with CanEnerco, Ltd. Under the terms of the agreement,
Columbia Resources and CanEnerco, Ltd. will jointly develop drilling properties
in southwestern Ontario, Canada.

On August 7, 1997, Columbia Resources acquired Alamco, Inc. (Alamco), a gas and
oil production company operating in the Appalachian Basin. On April 30, 1996,
Columbia sold Columbia Gas Development Corporation, its wholly owned southwest
exploration and production subsidiary, effective December 31, 1995. The
information contained in the following tables includes amounts attributable to
the operations and reserves of Alamco from August 7, 1997.

Reserve information contained in the following tables for the U.S. and Canadian
properties is management's estimate, which was reviewed by the independent
consulting firms of Ryder Scott Company Petroleum Engineers for the U.S.
reserves and Sproule Associates Limited for the Canadian reserves. Reserves are
reported as net working interest. Gross revenues are reported after deduction of
royalty interest payments.


                                       66
<PAGE>   67
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


<TABLE>
<CAPTION>
RESERVE QUANTITY INFORMATION                   United States                 Canada
- -------------------------------------------------------------------------------------------
                                                       Oil & Other              Oil & Other
                                             Gas         Liquids         Gas      Liquids
Proved Reserves                             (Bcf)       (000 Bbls)      (Bcf)    (000 Bbls)
- -------------------------------------------------------------------------------------------
<S>                                         <C>        <C>              <C>     <C>
Reserves as of December 31, 1995            599.5         1,651           --         --
     Revisions of previous estimate          78.9          (169)          --         --
     Extensions, discoveries
       and other additions                    5.5           161           --         --
     Production                             (33.6)         (281)          --         --
     Sale of reserves-in-place               (5.8)         (588)          --         --
- -------------------------------------------------------------------------------------------
Reserves as of December 31, 1996            644.5           774           --         --
     Revisions of previous estimate          69.5          (139)          --         --
     Extensions, discoveries
       and other additions                   33.2            59           --         --
     Production                             (34.7)         (210)          --         --
     Purchase of reserves-in-place(a)        88.0         1,216           --         --
- -------------------------------------------------------------------------------------------
Reserves as of December 31, 1997            800.5         1,700           --         --
     Revisions of previous estimate         (23.1)          178           --         --
     Extensions, discoveries
       and other additions                   60.7            94           --         --
     Production                             (39.0)         (201)        (0.1)     (13.0)
     Purchase of reserves-in-place             --            --          1.1       77.0
     Sale of reserves-in-place               (9.6)           --           --         --
- -------------------------------------------------------------------------------------------
RESERVES AS OF DECEMBER 31, 1998            789.5         1,771          1.0       64.0
- -------------------------------------------------------------------------------------------
Proved developed reserves as of
     December 31,
     1996                                   518.3           730           --         --
     1997                                   653.2         1,330           --         --
     1998                                   586.2         1,436          1.0       64.0
- -------------------------------------------------------------------------------------------
</TABLE>

(a)   Includes the purchase of Alamco.


<TABLE>
<CAPTION>
CAPITALIZED COSTS                           United States                      Canada                      Total
- -----------------------------------------------------------------------------------------------------------------------------
($ in millions)                       1998       1997       1996       1998     1997    1996     1998       1997       1996
- -----------------------------------------------------------------------------------------------------------------------------
<S>                                  <C>        <C>        <C>         <C>      <C>     <C>     <C>        <C>        <C>
CAPITALIZED COSTS AT YEAR END                                                                   
       Proved properties              673.2      628.4      475.4        1.4      --      --     674.6      628.4      475.4
       Unproved properties (a)         40.8       31.8       27.4        3.7      --      --      44.5       31.8       27.4
- -----------------------------------------------------------------------------------------------------------------------------
Total capitalized costs               714.0      660.2      502.8        5.1      --      --     719.1      660.2      502.8
Accumulated depletion                (225.2)    (196.0)    (146.4)      (0.2)     --      --    (225.4)    (196.0)    (146.4)
- -----------------------------------------------------------------------------------------------------------------------------
NET CAPITALIZED COSTS                 488.8      464.2      356.4        4.9      --      --     493.7      464.2      356.4
- -----------------------------------------------------------------------------------------------------------------------------
COSTS CAPITALIZED DURING YEAR (b)                                                               
   Acquisition properties                                                                       
       Proved                            --         --         --        0.7      --      --       0.7         --         --
       Unproved                         0.6        0.1        0.7        3.0      --      --       3.6        0.1        0.7
   Exploration                          2.3        1.0        2.7         --      --      --       2.3        1.0        2.7
   Development                         62.1      132.4        8.7        1.4      --      --      63.5      132.4        8.7
- -----------------------------------------------------------------------------------------------------------------------------
COSTS CAPITALIZED                      65.0      133.5       12.1        5.1      --      --      70.1      133.5       12.1
- -----------------------------------------------------------------------------------------------------------------------------
</TABLE>

(a)   Represents expenditures associated with properties on which evaluations
      have not been completed.

(b)   Includes internal costs capitalized pursuant to the accounting policy
      described in Note 1(F) of Notes to Consolidated Financial Statements of
      $3.3 million in 1998, $1.4 million in 1997 and $0.9 million in 1996.


                                       67
<PAGE>   68
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


<TABLE>
OTHER EXPLORATION AND PRODUCTION DATA                   United States                      Canada
- ---------------------------------------------------------------------------------------------------------
                                                  1998       1997       1996       1998     1997    1996
<S>                                              <C>        <C>        <C>        <C>      <C>     <C>
Average sales price per Mcf of gas ($)(a)          2.91       2.63       2.84       2.61     --      --
Average sales price per barrel                                                              
     of oil and other liquids ($)                 12.53      17.99      19.07      16.42     --      --
Production (lifting) cost per                                                               
     dollar of gross revenue ($)                   0.21       0.24       0.22       0.32     --      --
Depletion rate per dollar                                                                   
     of gross revenue ($)                          0.29       0.28       0.29       0.27     --      --
- ---------------------------------------------------------------------------------------------------------
</TABLE>

(a)   Includes the effect of hedging activities.


HISTORICAL RESULTS OF OPERATIONS

<TABLE>
<CAPTION>
                                     United States                   Canada                     Total
- ---------------------------------------------------------------------------------------------------------------
($ in millions)                1998      1997      1996      1998     1997    1996     1998      1997      1996
- ---------------------------------------------------------------------------------------------------------------
<S>                            <C>       <C>       <C>       <C>      <C>     <C>      <C>       <C>       <C>
Gross revenues                                                                       
       Unaffiliated            53.7      27.4      43.1       0.6      --      --      54.3      27.4      43.1
       Affiliated              62.3      69.0      58.8        --      --      --      62.3      69.0      58.8
Production costs               24.2      23.3      21.7       0.2      --      --      24.4      23.3      21.7
Depletion                      33.5      26.6      28.8       0.2      --      --      33.7      26.6      28.8
Income tax expense             20.7      14.3      15.1       0.1      --      --      20.8      14.3      15.1
- ---------------------------------------------------------------------------------------------------------------
RESULTS OF OPERATIONS          37.6      32.2      36.3       0.1      --      --      37.7      32.2      36.3
- ---------------------------------------------------------------------------------------------------------------
</TABLE>

Results of operations for exploration and production activities exclude
administrative and general costs, corporate overhead and interest expense.
Income tax expense is expressed at statutory rates less Section 29 credits.


STANDARDIZED MEASURE OF DISCOUNTED FUTURE NET CASH FLOWS

<TABLE>
<CAPTION>
                                        United States                     Canada                        Total
- ----------------------------------------------------------------------------------------------------------------------------
($ in millions)                 1998         1997       1996      1998     1997    1996      1998        1997        1996
- ----------------------------------------------------------------------------------------------------------------------------
<S>                            <C>         <C>         <C>        <C>      <C>     <C>      <C>         <C>         <C>
Future cash inflows            2,094.4     2,503.0     2,389.1     3.4      --      --      2,097.8     2,503.0     2,389.1
Future production costs         (585.5)     (719.9)     (715.5)   (1.5)     --      --       (587.0)     (719.9)     (715.5)
Future development costs        (200.4)     (182.7)     (165.8)   (0.1)     --      --       (200.5)     (182.7)     (165.8)
Future income tax expense       (487.8)     (557.5)     (499.7)   (0.7)     --      --       (488.5)     (557.5)     (499.7)
- ----------------------------------------------------------------------------------------------------------------------------
Future net cash flows            820.7     1,042.9     1,008.1     1.1      --      --        821.8     1,042.9     1,008.1
Less: 10% discount               440.1       582.2       574.4     0.3      --      --        440.4       582.2       574.4
- ----------------------------------------------------------------------------------------------------------------------------
STANDARDIZED MEASURE OF                                                            
     DISCOUNTED FUTURE                                                             
     NET CASH FLOW               380.6       460.7       433.7     0.8      --      --        381.4       460.7       433.7
- ----------------------------------------------------------------------------------------------------------------------------
</TABLE>

Future cash inflows are computed by applying year-end prices to estimated future
production of proved gas and oil reserves. Future expenditures (based on
year-end costs) represent those costs to be incurred in developing and producing
the reserves. Discounted future net cash flows are derived by applying a 10%
discount rate, as required by the Financial Accounting Standards Board, to the
future net cash flows. This data is not intended to reflect the actual economic
value of Columbia's gas and oil producing properties or the true present value
of estimated future cash flows since many arbitrary assumptions are used. The
data does provide a means of comparison among companies through the use of
standardized measurement techniques.


                                       68
<PAGE>   69
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


A reconciliation of the components resulting in changes in the standardized
measure of discounted cash flows attributable to proved gas and oil reserves for
the three years ending December 31, follows:

<TABLE>
<CAPTION>
                                         United States                       Canada                      Total
- ---------------------------------------------------------------------------------------------------------------------------
($ in millions)                    1998       1997       1996        1998     1997    1996     1998       1997       1996
- ---------------------------------------------------------------------------------------------------------------------------
<S>                               <C>        <C>        <C>          <C>      <C>     <C>     <C>        <C>         <C>
Beginning of year                  460.7      433.7      316.0         --       --      --     460.7      433.7      316.0
- ---------------------------------------------------------------------------------------------------------------------------
Gas and oil sales,                                                                           
     net of production costs       (91.9)     (73.1)     (80.2)      (0.4)      --      --     (92.3)     (73.1)     (80.2)
                                                                                             
Net changes in prices                                                                        
     and production costs         (108.5)    (107.8)     170.4         --       --      --    (108.5)    (107.8)     170.4
                                                                                             
Change in future                                                                             
     development costs             (10.0)     (16.9)       0.5         --       --      --     (10.0)     (16.9)       0.5
                                                                                             
Extensions, discoveries                                                                      
     and other additions,                                                                    
     net of related costs           77.5       51.9        9.4         --       --      --      77.5       51.9        9.4
                                                                                             
Revisions of previous                                                                        
     estimates, net of                                                                       
     related costs                 (18.0)      64.0       90.1         --       --      --     (18.0)      64.0       90.1
                                                                                             
Sales of reserves-in-place         (12.0)      (4.1)     (18.4)        --       --      --     (12.0)      (4.1)     (18.4)
                                                                                             
Purchases of reserves-in-place        --       67.0         --        1.7       --      --       1.7       67.0         --
                                                                                             
Accretion of discount               70.1       64.3       46.0         --       --      --      70.1       64.3       46.0
                                                                                             
Net change in income taxes          21.1      (30.5)     (65.3)      (0.5)      --      --      20.6      (30.5)     (65.3)
                                                                                             
Timing of production                                                                         
     and other changes              (8.4)      12.2      (34.8)        --       --      --      (8.4)      12.2      (34.8)
- ---------------------------------------------------------------------------------------------------------------------------
END OF YEAR                        380.6      460.7      433.7        0.8       --      --     381.4      460.7      433.7
- ---------------------------------------------------------------------------------------------------------------------------
</TABLE>


                                       69
<PAGE>   70
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)


                                                                      Schedule V

                        VALUATION AND QUALIFYING ACCOUNTS
                     Columbia Energy Group and Subsidiaries
                             Year Ended December 31,
                                 ($ in millions)


<TABLE>
<CAPTION>
                                                       Additions - Charged to
                                                       ----------------------
                                           Beginning               Other                         Ending
Description                                 Balance    Income    Accounts (a)   Deductions (b)   Balance
- --------------------------------------------------------------------------------------------------------
<S>                                        <C>         <C>       <C>            <C>              <C>
Reserves deducted in the balance sheet 
   from the assets to which they apply:

        Allowance for doubtful accounts

          1998                                18.7      43.1         6.6            34.2          34.2
                                                                                                 
          1997                                16.2      29.8        19.8            47.1          18.7
                                                                                                 
          1996                                12.3      25.6        17.7            39.4          16.2
- --------------------------------------------------------------------------------------------------------
</TABLE>

(a)   Primarily reflects reclassifications to a regulatory asset of the
      uncollectible accounts related to the Percent of Income Plan (PIP) of
      Columbia Gas of Ohio, Inc.

(b)   Principally reflects amounts charged off as uncollectible less amounts
      recovered.


                                       70
<PAGE>   71
ITEM 9. CHANGE IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL
        DISCLOSURE

None.

                                    PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

Certain information required by this item is contained in Columbia's Proxy
Statement related to the 1999 Annual Meeting of Stockholders, to be filed
pursuant to Section 14 of the Securities Exchange Act of 1934 and is
incorporated herein by reference.

Information regarding Columbia's current executive officers, is as follows:

OLIVER G. RICHARD III, 46, Chairman, President and Chief Executive Officer of
Columbia (since April 28, 1995). Chairman of New Jersey Resources Corporation
from 1992 to 1995; President and Chief Executive Officer from 1991 to 1995.
President and Chief Executive Officer of Northern Natural Gas Company from 1989
to 1991. Senior Vice President and subsequently Executive Vice President of
Enron Gas Pipeline Group from 1987 to 1989. Vice President and General Counsel
of Tenngasco, a subsidiary of Tenneco Corporation, from 1985 to 1987. Federal
Energy Regulatory Commission Commissioner from 1982 to 1985.

PETER M. SCHWOLSKY, 52, Senior Vice President and Chief Legal Officer of
Columbia and Columbia Energy Group Service Corporation since August 1995. Senior
Vice President from June 1995 to August 1995. Executive Vice President, Law and
Corporate Development, for New Jersey Resources Corporation from 1991 to 1995.
Of counsel and then Partner with Steptoe & Johnson from 1986 to 1991.

MICHAEL W. O'DONNELL, 54, Senior Vice President and Chief Financial Officer of
Columbia and Columbia Energy Group Service Corporation since October 1993.
Senior Vice President and Assistant Chief Financial Officer of Columbia and
Columbia Energy Group Service Corporation from 1989 to 1993.

CATHERINE GOOD ABBOTT, 48, Chief Executive Officer and President of Columbia Gas
Transmission Corporation and Chief Executive Officer of Columbia Gulf
Transmission Company since January 1996. Principal with Gem Energy Consulting,
Inc. from 1995 to January 1996. Vice president for various business units of
Enron Corporation from 1985 to 1995.

PATRICIA A. HAMMICK, 52, Senior Vice President for Strategy and Communications
for Columbia since May 1998. Vice President of the Natural Gas Supply
Association from 1983 through 1996. Manager, Energy Liason for the Gulf Oil
Exploration and Production Company from 1979 to 1983.

ITEM 11. EXECUTIVE COMPENSATION

Information required by this item is contained in Columbia's Proxy Statement
related to the 1999 Annual Meeting of Stockholders, to be filed pursuant to
Section 14 of the Securities Exchange Act of 1934 and is incorporated herein by
reference.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

Information required by this item is contained in Columbia's Proxy Statement
related to the 1999 Annual Meeting of Stockholders, to be filed pursuant to
Section 14 of the Securities Exchange Act of 1934 and is incorporated herein by
reference.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

Information required by this item is contained in Columbia's Proxy Statement
related to the 1999 Annual Meeting of Stockholders, to be filed pursuant to
Section 14 of the Securities Exchange Act of 1934 and is incorporated herein by
reference.


                                       71
<PAGE>   72
                                     PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

Exhibits

Reference is made to pages 74 through 76 for the list of exhibits filed as part
of this Annual Report on Form 10-K.

Pursuant to Item 601(b), paragraph (4)(iii)(A) of Regulation S-K, certain
instruments representing long-term debt of Columbia or its subsidiaries have not
been included as Exhibits because such debt does not exceed 10% of the total
assets of Columbia and its subsidiaries on a consolidated basis. Columbia agrees
to furnish a copy of any such instrument to the U.S. Securities and Exchange
Commission upon request.

Financial Statement Schedules

All of the financial statements and financial statement schedules filed as a
part of the Annual Report on Form 10-K are included in Item 8.

Reports on Form 8-K

A report on Form 8-K was filed on October 13, 1998, containing a Press Release
issued that day announcing earnings for the three and nine months ended
September 30, 1998.

<TABLE>
<CAPTION>
                       Financial
    Item               Statements
  Reported              Included          Date of Event           Date Filed                
  --------             ----------        ----------------      ----------------
<S>                    <C>               <C>                   <C>
     5                     Yes           October 13, 1998      October 13, 1998
</TABLE>

Undertaking made in Connection with 1933 Act Compliance on Form S-8

For purposes of complying with the amendments to the rules governing Form S-8
under the Securities Act of 1933, as amended (the Act), Columbia undertakes the
following, which is incorporated by reference into the registration statements
on Form S-8, Nos. 33-03869 (filed May 16, 1996) and 33-42776 (filed September
13, 1991):

Insofar as indemnification for liabilities arising under the Act may be
permitted to directors, officers and controlling persons of the registrant
pursuant to the foregoing provisions, or otherwise, the registrant has been
advised that in the opinion of the U.S. Securities and Exchange Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by 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 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 questions whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.


                                       72
<PAGE>   73
                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the registrant has duly caused this report to be signed on its
behalf by the undersigned, thereunto duly authorized.

                                        COLUMBIA ENERGY GROUP
                                            (Registrant)

Dated: March 26, 1999

                                        By: /s/ Oliver G. Richard III
                                            ----------------------------
                                            (Oliver G. Richard III)
                                              Director (Principal
                                              Executive Officer)

Pursuant to the requirements of the Securities Exchange Act of 1934, this report
has been signed below by the following persons on behalf of the registrant and
in the capacities and on the dates indicated.


<TABLE>
<S>                                                 <C>
March 26, 1999  /s/ Oliver G. Richard III           March 26, 1999  /s/ J. Bennett Johnston                                 
                ----------------------------                        ----------------------------
                Director (Principal                                 J. Bennett Johnston
                Executive Officer)                                  Director


March 26, 1999  /s/ Richard F. Albosta              March 26, 1999  /s/ Malcolm Jozoff                                       
                ----------------------------                        ----------------------------
                Richard F. Albosta                                  Malcolm Jozoff
                Director                                            Director


March 26, 1999  /s/ Robert H. Beeby                 March 26, 1999  /s/ William E. Lavery
                ----------------------------                        ----------------------------
                Robert H. Beeby                                     William E. Lavery
                Director                                            Director


March 26, 1999  /s/ Wilson K. Cadman                March 26, 1999  /s/ Gerald E. Mayo
                ----------------------------                        ----------------------------
                Wilson K. Cadman                                    Gerald E. Mayo
                Director                                            Director


March 26, 1999  /s/ Jeffrey W. Grossman             March 26, 1999  /s/ Michael W. O'Donnell
                ----------------------------                        ----------------------------
                Jeffrey W. Grossman                                 Michael W. O'Donnell
                Vice President & Controller                         Senior Vice President
                (Principal Accounting Officer)                      (Chief Financial Officer)


March 26, 1999  /s/ James P. Heffernan              March 26, 1999  /s/ Douglas E. Olesen
                ----------------------------                        ----------------------------
                James P. Heffernan                                  Douglas E. Olesen
                Director                                            Director


March 26, 1999  /s/ Karen L. Hendricks              March 26, 1999  /s/ William R. Wilson
                ----------------------------                        ----------------------------
                Karen L. Hendricks                                  William R. Wilson
                Director                                            Director


March 26, 1999  /s/ Malcolm T. Hopkins              
                ----------------------------
                Malcolm T. Hopkins
                Director
</TABLE>


                                       73
<PAGE>   74
EXHIBIT INDEX

Reference is made in the two right-hand columns below to those exhibits which
have heretofore been filed with the U.S. Securities and Exchange Commission.
Exhibits so referred to are incorporated herein by reference.

<TABLE>
<CAPTION>
                                                                                                       Reference
                                                                                              ----------------------------
                                                                                               File No.            Exhibit
<S>       <C>  <C>                                                                            <C>                 <C>
3-A       -    Restated Certificate of Incorporation of The Columbia                             1-1098               3-A
                 Gas System, Inc., dated as of November 28, 1995.
3-B       -    By-Laws of The Columbia Gas System, Inc., as amended dated                        1-1098               3-B
                 November 18, 1987.
3-C       -    Certificate of Ownership and Merger, Merging Columbia                             1-1098               3-C
                 Energy Group, Inc. into The Columbia Gas System, Inc.
4-A       -    Indenture between The Columbia Gas System, Inc.                                 33-64555               4-S
                 and Marine Midland Bank, N.A. Trustee, dated as of
                  November 28, 1995.
4-B       -    First Supplemental Indenture, between The Columbia Gas                          33-64555               4-T
                 System, Inc. and Marine Midland Bank, N.A. Trustee,
                 dated as of November 28, 1995.
4-C       -    Second Supplemental Indenture, between The Columbia Gas                         33-64555               4-U
                 System, Inc., and Marine Midland Bank, N.A. Trustee,
                 dated as of November 28, 1995.
4-D       -    Third Supplemental Indenture, between The Columbia Gas                          33-64555               4-V
                 System, Inc. and Marine Midland Bank, N.A. Trustee,
                 dated as of November 28, 1995.
4-E       -    Fourth Supplemental Indenture, between The Columbia Gas                         33-64555               4-W
                 System, Inc. and Marine Midland Bank, N.A. Trustee,
                 dated as of November 28, 1995.
4-F       -    Fifth Supplemental Indenture, between The Columbia Gas                          33-64555               4-X
                 System, Inc. and Marine Midland Bank, N.A. Trustee,
                 dated as of November 28, 1995.
4-G       -    Sixth Supplemental Indenture, between The Columbia Gas                          33-64555               4-Y
                 System, Inc. and Marine Midland Bank, N.A. Trustee,
                 dated as of November 28, 1995.
4-H       -    Seventh Supplemental Indenture, between The Columbia                            33-64555               4-Z
                 Gas System, Inc. and Marine Midland Bank, N.A., Trustee,
                 dated as of November 28, 1995.
4-I *     -    Instrument of Resignation, Appointment and Acceptance dated as
                 of  March 1, 1999, between Columbia Energy Group and Marine
                 Midland Bank, as Resigning Trustee and The First National Bank
                 of Chicago, as Successor Trustee
10-P(a)   -    Pension Restoration Plan of The Columbia Gas System, Inc.,                        1-1098              10-P
                 amended October 9, 1991.
10-Q(a)   -    Thrift Restoration Plan of The Columbia Gas System, Inc.                          1-1098              10-Q
                 dated January 1, 1989.
10-T      -    Agreement and Bridge Agreement dated December 1, 1993,                            1-1098              10-T
                 between Columbia Gas Transmission Corporation and
                 Consol Pennsylvania Coal Company.
10-AE     -    U.S. Environmental Protection Agency Administrative                               1-1098             10-AE
                 Order by Consent for Removal Actions for Columbia Gas
                 Transmission Corporation dated September 22, 1994.
10-AF     -    Amended and Restated Indenture of Mortgage and                                    1-1098             10-AF
                 Deed of Trust by Columbia Gas Transmission
                 Corporation to Wilmington Trust Company,
                 dated as of November 28, 1995
</TABLE>      

(a)   Executive Compensation arrangements filed pursuant to Item 14 of Form
      10-K.

*     Filed herewith.


                                       74
<PAGE>   75
EXHIBIT INDEX (continued)

<TABLE>
<CAPTION>
                                                                                                       Reference
                                                                                              ----------------------------
                                                                                               File No.            Exhibit
<S>       <C>  <C>                                                                            <C>                 <C>
10-BB(a)  -    Annual Incentive Compensation Plan of The Columbia Gas                            1-1098             10-BB
                 System, Inc., dated November 16, 1988.                                        
10-BC(a)  -    Employment Agreement between Oliver G. Richard III                                1-1098             10-BC
                 and The Columbia Gas System, Inc., dated March 15, 1995.                      
10-BE(a)  -    Employment Agreement between Peter M. Schwolsky                                   1-1098             10-BE
                 and The Columbia Gas System, Inc., dated May 30, 1995.                        
10-BF(a)  -    Employment Agreement between Catherine Good Abbott                              
                 and The Columbia Gas System, Inc., dated January 17, 1996.                    
10-BU     -    Share Sale and Purchase Agreement between The                                     1-1098             10-BU
                 Columbia Gas System, Inc. and Anderson Exploration                            
                 Ltd. dated November 25, 1991.                                                 
10-BV     -    Security Agreement dated as of January 15, 1992, between                          1-1098             10-BV
                 The Columbia Gas System, Inc. and Anderson                                    
                 Exploration Ltd. and Montreal Trust Company of Canada.                        
10-BW     -    Kotaneelee Litigation Indemnity Agreement dated                                   1-1098             10-BW
                 as of December 31, 1991, among The Columbia Gas                               
                 System, Inc. and Columbia Gas Development                                     
                 of Canada Ltd. and Anderson Exploration Ltd.                                  
10-BX     -    Specified Litigation Indemnity Agreement made                                     1-1098             10-BX
                 as of December 31, 1991, among The Columbia                                   
                 Gas System, Inc. and Columbia Gas Development                                 
                 of Canada Ltd. and Anderson Exploration Ltd.                                  
10-BY(a)  -    Columbia Gas Restoration Security Trust Agreement dated,                          1-1098             10-BY
                 June 1, 1991,with Dauphin Deposit Bank and Trust Company.                     
10-CA(a)  -    The Columbia Gas System, Inc. Retirement Plan                                     1-1098             10-CA
                 for Outside Directors, as amended, August 21, 1991.                           
10-CB     -    Credit Agreement, dated as of November 28, 1995, among The                        1-1098             10-CB
                Columbia Gas System, Inc., certain banks party thereto                         
                and Citibank, N.A.                                                             
10-CC     -    First Amendment and Supplement to Credit                                          1-1098             10-CC
                 Agreement, dated December 6, 1995                                             
10-CD     -    Credit Agreement for $450,000,000, dated March 11, 1998,                          1-1098             10-CD
                 among Columbia Energy Group and certain banks party thereto                   
                 and Citibank, N.A. as Administrative and Syndication Agent.                   
10-CE     -    Credit Agreement for $900,000,000, dated March 11, 1998,                          1-1098             10-CE
                 among Columbia Energy Group and certain banks party thereto                   
                 and Citibank, N.A. as Administrative and Syndication Agent.                   
10-CF     -    Memorandum of Understanding among the Millennium Pipeline                         1-1098             10-CF
                 Project partners (Columbia Transmission, West Coast Energy, MCN               
                 Investment Corp. and TransCanada Pipelines Limited) dated                     
                 December 1, 1997.                                                             
10-CG *   -    Agreement of Limited Partnership of Millennium Pipeline                         
                 Company, L.P. dated May 31, 1998.                                             
10-CH *   -    Contribution Agreement Between Columbia Gas Transmission                        
                 Corporation and Millennium Pipeline Company, L.P. dated July 31, 1998         
10-CI *   -    Regulations of Millennium Pipeline Management Company, L.L.C.                   
                 dated May 31, 1998                                                            
10-CJ     -    Amended and Restated Agreement of Cove Point                                      1-1098             10-CJ
                LNG Limited Partnership between Columbia LNG and                            
                PEPCO Energy Company, Inc. dated January 27, 1994.
</TABLE>

(a)   Executive Compensation arrangements filed pursuant to Item 14 of Form
      10-K.

*     Filed herewith.


                                       75
<PAGE>   76
EXHIBIT INDEX (continued)

<TABLE>
<CAPTION>
                                                                                                       Reference
                                                                                              ----------------------------
                                                                                               File No.            Exhibit
<S>       <C>  <C>                                                                            <C>                 <C>
10-CK *   -    Amended and Restated 364-Day Credit Agreement among Columbia
                 Energy Group and certain banks party thereto and Citibank, N. A.
                 as Administrative and Syndication Agent dated as of March 10, 1999.
10-CM     -    Plan of Reorganization for Columbia Gas Transmission Corporation                 1-1098              10-CM
                 as filed with the United States Bankruptcy Court for the District
                 of Delaware on January 18, 1994.
12 *      -    Statements of Ratio of Earnings to Fixed Charges
21 *      -    Subsidiaries of Columbia Energy Group
23-A *    -    Letter report, dated January 22, 1999, and the written consent to
                 the filing and use of information contained in such letter report,
                 Reports and Registration Statements filed during 1998, of Ryder
                 Scott Company Petroleum Engineers, independent petroleum and
                 natural gas consultants.
23-B *    -    Written consent of Arthur Andersen LLP, independent public
                 accountants, to the incorporation by reference of their report
                 included in the 1998 Annual Report on Form 10-K of Columbia
                 Energy Group and their report included in Columbia Energy Group's
                 1998 Annual Report to Shareholders in the registration statements
                 on Form S-8 (File No. 33-03869), and Form S-8 (File No. 33-42776).
23-C *    -    Letter report, dated February 2, 1999, and the written consent to the filing
                 and use of information contained in such letter report, Reports and
                 Registration Statements filed during 1998, of Sproule Associates Limited,
                 independent  petroleum and natural gas consultants.
27 *      -    Financial Data Schedule for the period ended December 31, 1998.
</TABLE>

*     Filed herewith.


                                       76

<PAGE>   1
                                                                      Exhibit 4I






                              COLUMBIA ENERGY GROUP
                (FORMERLY NAMED "THE COLUMBIA GAS SYSTEM, INC.")

                                       AND

                    MARINE MIDLAND BANK, AS RESIGNING TRUSTEE

                                       AND

            THE FIRST NATIONAL BANK OF CHICAGO, AS SUCCESSOR TRUSTEE


              INSTRUMENT OF RESIGNATION, APPOINTMENT AND ACCEPTANCE

                            Dated as of March 1, 1999
<PAGE>   2
                              COLUMBIA ENERGY GROUP
              INSTRUMENT OF RESIGNATION, APPOINTMENT AND ACCEPTANCE
                            Dated as of March 1, 1999

                                TABLE OF CONTENTS



PARTIES........................................................................1
                                                                           
RECITALS.......................................................................1
                                                                           
ARTICLE I.    TRUSTEE SUCCESSION...............................................2
                                                                           
Section 1.01  Resignation of Trustee...........................................2
Section 1.02  Appointment of Successor Trustee.................................2
Section 1.03  Acceptance and Assurances by Successor Trustee...................2
Section 1.04  Confirmatory Assignment..........................................2
Section 1.05  Costs and Expenses...............................................2
Section 1.06  Y2K..............................................................3
                                                                           
ARTICLE II.   MISCELLANEOUS PROVISIONS.........................................3
Section 2.01  Definitions; Use of Terms in this Agreement......................3
Section 2.02  Effect of Table of Contents and Headings.........................3
Section 2.03  Trust Indenture Act to Control...................................3
Section 2.04  Counterparts.....................................................3
Section 2.05  Company Warranties and Representations...........................3
                                                                           
TESTIMONIUM....................................................................4
                                                                           
SIGNATURES.....................................................................4
                                                                           
ACKNOWLEDGEMENTS...............................................................6
                                                                           
EXHIBIT A     Form of Notice to Holders........................................1
                                                                         

                                        i
<PAGE>   3
                                     PARTIES

      THIS INSTRUMENT OF RESIGNATION, APPOINTMENT AND ACCEPTANCE, dated as of
March 1, 1999 (herein "this Agreement") among COLUMBIA ENERGY GROUP, a Delaware
corporation (formerly named "The Columbia Gas System, Inc. and hereinafter
called the Company), MARINE MIDLAND BANK, a banking corporation and trust
company organized and existing under the laws of the State of New York, as
trustee under the Indenture referred to in the first recital hereof (hereinafter
called the Trustee), and THE FIRST NATIONAL BANK OF CHICAGO, a national banking
association (hereinafter called the Successor Trustee).

                                    RECITALS

      WHEREAS, the Company has heretofore executed and delivered to the Trustee
its Indenture dated as of November 28, 1995 and seven Supplemental Indentures
thereto, each dated as of November 28, 1995 (said Indenture being hereinafter
called the Original Indenture, and the Original Indenture together with all
indentures stated to be supplemental thereto, being hereinafter called the
Indenture); and

      WHEREAS, the Company has issued, and there are outstanding under the
Indenture,
$310,876,000 in aggregate principal amount of 6.39% Debentures Due
November 2000,
$281,530,000 in aggregate principal amount of 6.61% Debentures Due
November 2002,
$281,530,000 in aggregate principal amount of 6.80% Debentures Due
November 2005,
$281,530,000 in aggregate principal amount of 7.05% Debentures Due
November 2007,
$281,530,000 in aggregate principal amount of 7.32% Debentures Due
November 2010, 
$281,530,000 in aggregate principal amount of 7.42% Debentures Due 
November 2015, 
$281,530,000 in aggregate principal amount of 7.62% Debentures Due
November 2025; and

      WHEREAS, the Trustee wishes to resign and the Company wishes to appoint
the Successor Trustee as the Trustee's replacement; and

      WHEREAS, pursuant to Section 6.08 of the Indenture, the Successor Trustee
must deliver a written acceptance of its appointment to the Trustee and to the
Company; and

      WHEREAS, upon the terms of this Agreement, the Company is willing to take
action to permit the succession of the Successor Trustee to the trusteeship
under the Indenture; and

      WHEREAS, each of the parties hereto confirms to the others that its
execution and delivery of this Agreement and other necessary actions have been
duly authorized by, or pursuant to authority granted by, its Board of Directors
and have been duly approved to the extent required by law by the appropriate
governmental authorities; and

      WHEREAS, all acts and things necessary to make this Agreement, when
executed and delivered by each of the parties, a valid, binding and legal
agreement of such party have been done and performed.

      NOW, THEREFORE, in consideration of the premises, and of other good and
valuable consideration, the receipt whereof is hereby acknowledged, the parties
hereby agree as follows:
<PAGE>   4
                                   ARTICLE I.

                               TRUSTEE SUCCESSION

      Section 1.01 Resignation of Trustee. Pursuant to Section 6.08 of the
Indenture, the Trustee hereby resigns as trustee under the Indenture, effective
at the opening of business on March 1, 1999. The Company acknowledges receipt of
the notice of resignation from the Trustee required under said Section 6.08. The
Trustee covenants to and with the Company that all actions which have been and
will be taken by the Trustee in connection with the succession of the
trusteeship under the Indenture (including, without limitation, transfers of any
funds or other property held in trust under the Indenture) have been and will be
proper under the Indenture and fully protective of the respective interests of
the Company and the holders of Securities issued and to be issued under the
Indenture.

      Section 1.02 Appointment of Successor Trustee. Pursuant to Section 6.08 of
the Indenture, and in reliance upon the agreements and assurances of the Trustee
and Successor Trustee contained in this Agreement, the Company hereby appoints
the Successor Trustee as the new trustee under the Indenture. This appointment
shall be effective upon the effectiveness of the resignation of the Trustee
under the Indenture at the opening of business on March 1, 1999, and fully vests
the Successor Trustee with all the estates, properties, rights, powers, trusts,
duties and obligations of its predecessor in trust under the Indenture, with
like effect as if originally named as trustee thereunder. The Successor Trustee
shall mail to Securityholders notice (in the form of Exhibit A attached hereto)
of such appointment in the manner provided in Section 6.08 of the Indenture.

      Section 1.03 Acceptance and Assurances by Successor Trustee. The Successor
Trustee hereby accepts appointment as Successor Trustee under the Indenture, and
assumes all rights, powers, duties and obligations of the trustee under the
Indenture. In connection therewith, the Successor Trustee confirms its
eligibility and qualification under Section 6.10 of the Indenture. All funds or
other property received by the Successor Trustee from the Trustee or the
Company, either in the Successor Trustee's capacity as agent of the Trustee or
by virtue of the Successor Trustee's acceptance of appointment hereunder and the
conveyance made to it under Section 6.08 hereof, have been received and are held
by the Successor Trustee in trust under the Indenture in full protection of the
respective interests of the Company and the holders of Securities issued and to
be issued under the Indenture.

      Section 1.04 Confirmatory Assignment. In order more certainly to vest and
confirm the same in the Successor Trustee, the Trustee by these presents does
give, grant, bargain, sell, transfer, assign, convey and confirm unto the
Successor Trustee all the estates, properties, rights, powers, trusts, duties
and obligations of the Trustee as trustee under the Indenture, effective at the
opening of business on March 1, 1999.

      Section 1.05 Costs and Expenses. As between the Trustee and the Company,
the Company hereby agrees to pay or reimburse the Trustee for payment of all
reasonable termination costs and expenses relating to or arising out of the
succession of the trusteeship under the Indenture, including, without
limitation, reasonable legal fees and expenses, and expenses of giving required
notice of, and documenting of, the succession, and any expenses incurred in the
event of Securityholder action to appoint a trustee to replace the Successor
<PAGE>   5
Trustee under Section 6.08 of the Indenture. Notwithstanding the foregoing, with
respect to fees not related to and not arising out of the succession of the
trusteeship under the Indenture, the Trustee's 1999 annual fee shall be pro
rated up to and including the date of succession. The Successor Trustee's annual
fee for 1999 will likewise be pro rated, commencing with the day after the
succession.

      Section 1.06 Y2K. Consistent with the recommendations of the Comptroller
of the Currency, all financial institutions were required to have their year
2000 conversions and unit testing associated with such conversions completed by
December 31, 1998, thereby allowing internal and external interface testing,
including testing with customers, during 1999 to ensure that all systems are
working properly and reliably. The Successor Trustee represents that it has
completed unit testing for major systems which support the services being
contemplated in this Agreement related to the year 2000 century date change.
This effort is part of a vigorous and comprehensive project to inventory,
assess, renovate or replace and test affected systems. The system(s) which
support the service being offered in this Agreement are part of that effort.


                                   ARTICLE II.

                            MISCELLANEOUS PROVISIONS

      Section 2.01 Definitions; Use of Terms in this Agreement. The use of terms
and expressions herein is in accordance with the definitions and constructions
contained in the Indenture.

      Section 2.02 Effect of Table of Contents and Headings. The Table of
Contents and headings of the different Articles and Sections of this Agreement
are inserted for convenience of reference, and are not to be taken to be any
part of those provisions, or to control or affect the meaning, construction or
effect of the same.

      Section 2.03 Trust Indenture Act to Control. If any provision of this
Agreement limits, qualifies or conflicts with the duties imposed by any of
Sections 310 to 317, inclusive, of the Trust Indenture Act of 1939, as amended
by the Trust Indenture Reform Act of 1990, through operation of Section 318(c),
such imposed duties shall control.

      Section 2.04 Counterparts. This Agreement may be executed in any number of
counterparts and on separate counterparts, each of which shall be deemed an
original; and all said counterparts executed and delivered, each as an original,
shall constitute but one and the same instrument, which shall for all purposes
be sufficiently evidenced by any such original counterpart.

      Section 2.05 Company Warranties and Representations. The Company hereby
represents and warrants to the Successor Trustee that:

      (a) This Agreement has been duly and validly authorized, executed, and
      delivered by the Company; and

      (b) The Company is unaware of any "Event of Default" (as defined in
      Section 5.01 of the Indenture).
<PAGE>   6
                                   TESTIMONIUM

      IN WITNESS WHEREOF, Columbia Energy Group has caused this Agreement 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 or one of its Assistant Treasurers,
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 Agreement 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, and The First National Bank of Chicago has
caused this Agreement 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 March 1, 1999.


                                   SIGNATURES


                                        COLUMBIA ENERGY GROUP



Attest:_____________________________    By:____________________________
       Secretary



[CORPORATE SEAL]





                                        MARINE MIDLAND BANK, as Trustee



Attest:_____________________________    By:____________________________



[CORPORATE SEAL]
<PAGE>   7
                                        THE FIRST NATIONAL BANK OF
                                        CHICAGO, as Successor Trustee



Attest:_____________________________    By:____________________________



[CORPORATE SEAL]
<PAGE>   8
                                ACKNOWLEDGEMENTS


COMMONWEALTH OF VIRGINIA            )
                                    )     ss:
CITY/COUNTY OF _____________        )

      On this _____ day of ___________________, ______, before me personally
came __________________, to me known, who, being by me duly sworn, did depose
and say that he resides at __________________________________________; that he
is _______________ of Columbia Energy Group, 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.


                                        ___________________________________
                                        Notary Public


                                        ___________________________________
                                        My commission expires


STATE OF NEW YORK                   )
                                    )     ss:
COUNTY OF NEW YORK                  )

      On the _____ day of ___________________, ______, before me personally came
__________________, to me known, who, being by me duly sworn, did depose and say
that he resides at __________________________________________; that he is
_______________ 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.


                                        ___________________________________
                                        Notary Public


                                        ___________________________________
                                        My commission expires
<PAGE>   9
STATE OF _____________________      )
                                    )     ss:
CITY/COUNTY OF ______________       )

      On the _____ day of ___________________, ______, before me personally came
__________________, to me known, who, being by me duly sworn, did depose and say
that he resides at __________________________________________; that he is
_______________ of The First National Bank of Chicago, 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.


                                        ___________________________________
                                        Notary Public


                                        ___________________________________
                                        My commission expires
<PAGE>   10
                                    EXHIBIT A

                               (Notice to Holders)

                            NOTICE TO THE HOLDERS OF

                              COLUMBIA ENERGY GROUP
                 (FORMERLY NAMED THE COLUMBIA GAS SYSTEM, INC.)
                        DEBENTURES DUE _________________
                                  CUSIP #______
                               (THE "DEBENTURES")

NOTE: THIS NOTICE CONTAINS IMPORTANT INFORMATION THAT IS OF INTEREST TO THE
BENEFICIAL OWNERS OF THE SUBJECT DEBENTURES. IF APPLICABLE, ALL DEPOSITORIES,
CUSTODIANS AND OTHER INTERMEDIARIES RECEIVING THIS NOTICE ARE REQUESTED TO
EXPEDITE RE-TRANSMITTAL TO SUCH BENEFICIAL OWNERS IN A TIMELY MANNER.

      The First National Bank of Chicago ("First Chicago"), on behalf of
Columbia Energy Group (formerly named The Columbia Gas System, Inc.) (the
"Company"), hereby notifies holders of the Debentures of the resignation of
Marine Midland Bank, as trustee (the "Resigning Trustee") under the Indenture
dated as of November 28, 1995, as supplemented by seven Supplemental Indentures
thereto dated as November 28, 1995 (collectively, the "Indenture") between the
Company and the Resigning Trustee, under which Indenture the Debentures were
issued.

      The Company has appointed The First National Bank of Chicago as successor
trustee (the "Successor Trustee") under the Indenture, whose corporate trust
office is located at One First National Plaza, Suite 0126, Chicago, Illinois
60670-0126, which appointment has been accepted and became effective at the
opening of business on March 1, 1999.

      The Successor Trustee, on behalf of the Company, also hereby notifies
holders of the Debentures of the resignation of the Resigning Trustee as
Registrar and Paying Agent effective at the opening of business on March 1,
1999, and the simultaneous appointment of the Successor Trustee as Registrar and
Paying Agent. Effective March 1, 1999, the address for the Registrar and Paying
Agent will be:

            The First National Bank of Chicago
            One First National Plaza
            Suite 0126
            Chicago, Illinois  60670-0126
            Attn:  Corporate Trust Services Division

      The above-referenced CUSIP number is for convenience only and neither the
Resigning Trustee, the Successor Trustee nor the Company shall be responsible
for any error of any nature relating to the CUSIP number.

            By: The First National Bank of Chicago,
                as Successor Trustee


                                        1

<PAGE>   1
                                                                    Exhibit 10CG



                                    AGREEMENT

                                       OF

                               LIMITED PARTNERSHIP

                                       OF

                        MILLENNIUM PIPELINE COMPANY, L.P.
<PAGE>   2
                                TABLE OF CONTENTS

                                                                        PAGE NO.

ARTICLE 1

      DEFINITIONS

      1.01  Defined Terms......................................................1
      (a)   "AAA"..............................................................1
      (b)   "Abstaining Partner"...............................................1
      (c)   "Act"..............................................................1
      (d)   "Additional Capital Contributions".................................2
      (e)   "Adjusted Capital Account Deficit".................................2
      (f)   "Affiliate"........................................................2
      (g)   "Affiliate Transaction"............................................2
      (h)   "Agreement"........................................................2
      (i)   "Allocation Year"..................................................2
      (j)   "Base Interest Rate"...............................................2
      (k)   "Budget"...........................................................3
      (l)   "Business Day".....................................................3
      (m)   "Capacity Lease and Exchange Agreement"............................3
      (n)   "Capital Account"..................................................3
      (o)   "Capital Contribution".............................................4
      (p)   "Change in Control"................................................4
      (q)   "Code".............................................................4
      (r)   "Columbia".........................................................4
      (s)   "Commitment Voting Date"...........................................5
      (t)   "Contribution Agreement"...........................................5
      (u)   "Contribution Date.................................................5
      (v)   "Credit Support Documents".........................................5
      (w)   "Debt".............................................................5
      (x)   "Delinquent Partner"...............................................5
      (y)   "Depreciation".....................................................5
      (z)   "Dispose," "Disposing" or "Disposition"............................6
      (aa)  "Dispute"..........................................................6
      (bb)  "Effective Date"...................................................6
      (cc)  "FERC".............................................................6
      (dd)  "General Interest Rate"............................................6
      (ee)  "General Partner"..................................................6
      (ff)  "Gross Asset Value"................................................6
      (gg)  "Initial Capital Contributions"....................................7
      (hh)  "In-Service Date"..................................................7
      (ii)  "Interest".........................................................7
      (jj)  "Lake Crossing Agreement"..........................................7


                                        i
<PAGE>   3
                                TABLE OF CONTENTS
                                   (CONTINUED)

                                                                        PAGE NO.


      (kk)  "Limited Partner"..................................................8
      (ll)  "Limited Partner Owner"............................................8
      (mm)  "Liquidator".......................................................8
      (nn)  "Losses"...........................................................8
      (oo)  "Millennium Pipeline System".......................................8
      (pp)  "MOU"..............................................................8
      (qq)  "Net Cash Flow"....................................................8
      (rr)  "Nonrecourse Deductions"...........................................8
      (ss)  "Nonrecourse Liability"............................................8
      (tt)  "O&M Agreement"....................................................8
      (uu)  "Partner Nonrecourse Debt".........................................8
      (vv)  "Partner Nonrecourse Debt Minimum Gain"............................9
      (ww)  "Partner Nonrecourse Deductions"...................................9
      (xx)  "Partners".........................................................9
      (yy)  "Partnership"......................................................9
      (zz)  "Partnership Property".............................................9
      (aaa) "Person"...........................................................9
      (bbb) "Precedent Agreements".............................................9
      (ccc) "Prime Rate".......................................................9
      (ddd) "Profits" and "Losses".............................................9
      (eee) "Project Agreements"..............................................10
      (fff) "Project Development Agreement"...................................10
      (ggg) "PUHCA"...........................................................11
      (hhh) "PUHCA Company"...................................................11
      (iii) "Regulatory Allocations"..........................................11
      (jjj) "Required Accounting Practices"...................................11
      (kkk) "Required Interest"...............................................11
      (lll) "Sale Notice......................................................11
      (mmm) "Scheduled Capital Contributions".................................11
      (nnn) "Substitute Limited Partner"......................................11
      (ooo) "System Modification".............................................11
      (ppp) "Treasury Regulations"............................................11
      (qqq) "UCC".............................................................11
      (rrr) "Unanimous Consent"...............................................11
      (sss) "Unit"............................................................12
      (ttt) "Withdrawal Effective Date".......................................12
      (uuu) "Withdrawal Notice"...............................................12
      (vvv) "Withdrawal Period"...............................................12
      (www) "Withdrawing Limited Partner".....................................12
      1.02  Construction......................................................12


                                       ii
<PAGE>   4
                                TABLE OF CONTENTS
                                   (CONTINUED)

                                                                        PAGE NO.

ARTICLE 2

      ORGANIZATION

      2.01  Formation.........................................................12
      2.02  Name..............................................................13
      2.03  Registered Agent and Registered Office............................13
      2.04  Location of Principal Place of Business...........................13
      2.05  Business and Purpose..............................................13
      2.06  Term..............................................................13
      2.07  Filing of Certificates............................................13
      2.08  General and Original Limited Partners' Units and Interests........13
      2.09  Additional Limited Partners.......................................14
      2.10  Organization Certificates.........................................14
      2.11  Power of Attorney.................................................14

ARTICLE 3

      CAPITALIZATION AND FINANCING

      3.01  Commencement of Operations........................................15
      3.02  Initial Capital Contributions.....................................15
      3.03  Scheduled and Additional Capital Contributions....................15
      3.04  Failure to Contribute.............................................16
      3.05  Partnership Borrowing.............................................16
      3.06  Additional Financing..............................................17
      3.07  Revenues..........................................................17
      3.08  Partnership Capital...............................................17
      3.09  Advances by Partners..............................................17
      3.10  Capital Accounts..................................................18
      3.11  Capital Contributions for System Modifications....................18

ARTICLE 4

      ALLOCATIONS AND DISTRIBUTIONS

      4.01  Profits...........................................................18
      4.02  Losses............................................................18
      4.03  Special Federal Income Tax Allocations............................19


                                       iii
<PAGE>   5
                                TABLE OF CONTENTS
                                   (CONTINUED)

                                                                        PAGE NO.

      (a)   Minimum Gain Chargeback...........................................19
      (b)   Partner Minimum Gain Chargeback...................................19
      (c)   Qualified Income Offset...........................................19
      (d)   Nonrecourse Deductions............................................20
      (e)   Partner Nonrecourse Deductions....................................20
      (f)   Section 754 Adjustments...........................................20
      4.04  Curative Allocations..............................................20
      4.05  Loss Limitation...................................................20
      4.06  Other Allocation Rules............................................21
      4.07  Contributed Property; Tax Allocations.............................21
      4.08  Distributions.....................................................22

ARTICLE 5

      RIGHTS AND DUTIES OF THE GENERAL PARTNER

      5.01  Management........................................................22
      5.02  Reliance by Public................................................22
      5.03  Restrictions on Authority of General Partner......................23
      5.04  Other Operations..................................................24
      5.05  Disposition of All or Substantially All of Partnership Property...24
      5.06  Contracts with the Partners or their Affiliates...................24
      5.07  Liabilities and Indemnification of the General Partner............24
      5.08  Title to Partnership Properties...................................25
      5.09  Transfer of Interest of General Partner...........................25
      5.10  Compensation......................................................25

ARTICLE 6

      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS

      6.01  Limitation of Liability...........................................26
      6.02  Management of Business............................................26
      6.03  Conflicts of Interest.............................................26
      6.04  Restrictions on Disposition of Limited Partner's Interest.........27
      6.05  Right of First Refusal............................................29
      6.06  Assignee's Rights.................................................29
      6.07  No Liability of General Partner for Distributions.................30
      6.08  Indemnification...................................................30
      6.09  No Dissolution Caused.............................................30


                                       iv
<PAGE>   6
                                TABLE OF CONTENTS
                                   (CONTINUED)

                                                                        PAGE NO.

      6.10  PUHCA.............................................................30
      6.11  Remedies..........................................................30

ARTICLE 7

      WITHDRAWAL OF THE GENERAL PARTNER AND LIMITED PARTNERS;
      ADMISSION OF ADDITIONAL GENERAL PARTNERS

      7.01  Withdrawal of the General Partner.................................31
      7.02  Admission of Additional General Partner...........................31
      7.03  Withdrawal of a Limited Partner and Effect of Withdrawal..........31

ARTICLE 8

      FISCAL YEAR; BOOKS OF ACCOUNT;
      BANK ACCOUNTS; AND REPORTS

      8.01  Books and Records.................................................33
      8.02  Bank Accounts.....................................................33
      8.03  Tax Elections.....................................................33
      8.04  Annual and Quarterly Reports......................................34
      8.05  Tax Reporting Information.........................................34
      8.06  Reporting Expenses................................................35

ARTICLE 9

      REPRESENTATIONS AND WARRANTIES OF LIMITED PARTNERS

      9.01  Representations and Warranties....................................35

ARTICLE 10

      DISSOLUTION, WINDING UP AND TERMINATION; CONTINUATION

      10.01 Events of Dissolution.............................................37
      10.02 Continuation of Business..........................................37
      10.03 Agreement of Successor General Partner............................38
      10.04 Liquidation.......................................................38
      10.05 Distributions in Kind.............................................39


                                        v
<PAGE>   7
                                TABLE OF CONTENTS
                                   (CONTINUED)

                                                                        PAGE NO.

ARTICLE 11

      AMENDMENT OF PARTNERSHIP AGREEMENT;
      MEETINGS; RECORD DATE

      11.01 Amendments to be Adopted Solely by General Partner................40
      11.02 Amendments to be Adopted with Consent of Limited Partners.........40
      11.03 Consent of General Partner Required...............................41
      11.04 Meetings..........................................................42
      11.05 Action Without a Meeting..........................................42
      11.06 Record Date.......................................................42

ARTICLE 12

      DISPUTE RESOLUTION

      12.01 Disputes..........................................................43
      12.02 Negotiations to Resolve Disputes..................................43
      12.03 Arbitration.......................................................43

ARTICLE 13

      GENERAL PROVISIONS

      13.01 Payments and Offset...............................................45
      13.02 Notices...........................................................45
      13.03 Ratification......................................................46
      13.04 Execution and Counterparts........................................46
      13.05 Waiver of Partition...............................................46
      13.06 Governing Law, Successors, Severability...........................46
      13.07 Entire  Agreement; Acknowledgment.................................47
      13.08 No Waiver.........................................................47
      13.09 Legends...........................................................47
      13.10 Presumptions......................................................47
      13.11 Time of Essence...................................................47

Exhibit A
Initial Partners, Units, Partnership Interest and Initial Capital
Contributions................................................................A-1


                                       vi
<PAGE>   8
                                TABLE OF CONTENTS
                                   (CONTINUED)

                                                                        PAGE NO.

Exhibit B
Limited Partner Owners.......................................................B-1


                                      vii
<PAGE>   9
                        AGREEMENT OF LIMITED PARTNERSHIP
                                       OF
                        MILLENNIUM PIPELINE COMPANY, L.P.


      THIS AGREEMENT OF LIMITED PARTNERSHIP, dated effective as of May 31, 1998,
by and among Millennium Pipeline Management Company, L.L.C., a Delaware limited
liability company (the "General Partner"), and those Persons signatory hereto
executing as "Limited Partners."

                                    PREAMBLE

      The General Partner and the Limited Partners have formed the Partnership
(defined below) to construct and own an interstate natural gas transmission
system (the "Millennium Pipeline System") extending from an interconnection with
a natural gas transmission system to be owned and operated by TransCanada
PipeLines Limited at the border between the United States and Canada in Lake
Erie to a terminus in Westchester County, New York. The Partners (defined below)
anticipate that the Millennium Pipeline System will be project financed and will
be in service by the end of 2000.

                                    ARTICLE 1

                                   DEFINITIONS

      1.01 Defined Terms. As used in this Agreement, the following terms shall
have the meanings set forth below when capitalized:

            (a) "AAA" shall have the meaning set forth in Section 12.03 hereof.

            (b) "Abstaining Partner" means any Partner that has elected to
      abstain from voting on any matter to be voted on by the Partners.

            (c) "Act" means the Delaware Revised Uniform Limited Partnership
      Act; Del. Code Ann. Title 6 Sections 17-101 to 17-1111, as amended
      from time to time.


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


UNITS IN MILLENNIUM PIPELINE COMPANY, L.P. HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS AND MAY
NOT BE OFFERED FOR SALE, SOLD OR OTHERWISE TRANSFERRED UNLESS SUBSEQUENTLY
REGISTERED UNDER SUCH ACTS OR UNLESS AN EXEMPTION FROM SUCH REGISTRATION IS
AVAILABLE. THIS AGREEMENT CONTAINS ADDITIONAL RESTRICTIONS ON SALES AND OTHER
TRANSFERS OF UNITS.
<PAGE>   10
            (d) "Additional Capital Contributions" means Capital Contributions
      made by the Partners in excess of the Initial Capital Contributions or the
      Scheduled Capital Contributions.

            (e) "Adjusted Capital Account Deficit" means, with respect to any
      Partner, the deficit balance, if any, in such Partner's Capital Account as
      of the end of the relevant Allocation Year, after giving effect to the
      following adjustments:

                  (i) Credit to such Capital Account any amounts which such
            Partner is deemed to be obligated to restore pursuant to the
            penultimate sentences in Sections 1.704-2(g)(1) and 1.704-2(i)(5) of
            the Treasury Regulations; and

                  (ii) Debit to such Capital Account the items described in
            Sections 1.704- 1(b)(2)(ii)(d)(4), 1.704-1(b)(2)(ii)(d)(5) and
            1.704-1(b)(2)(ii)(d)(6) of the Treasury Regulations.

            The foregoing definition of Adjusted Capital Account Deficit is
      intended to comply with the provisions of Section 1.704-1(b)(2)(ii)(d) of
      the Treasury Regulations and shall be interpreted consistently therewith.

            (f) "Affiliate" means, with respect to any Person, any other Person
      that directly or indirectly through one or more intermediaries controls or
      is controlled by or is under common control with the Person. The terms
      "controls," "controlled by" and "under common control with" shall each
      mean the possession, directly or indirectly or through one or more
      intermediaries, of more than fifty percent (50%) of the outstanding voting
      stock of, or the power to direct or cause the direction of the management
      policies of any Person, whether through ownership of stock, as a general
      partner or trustee, by contract or otherwise.

            (g) "Affiliate Transaction" means a business transaction between the
      Partnership and any Limited Partner or any Affiliate thereof; provided,
      however, that "Affiliate Transaction" shall not include the Project
      Agreements or any transaction between the Partnership and a Limited
      Partner or any Affiliate thereof for transportation of natural gas or
      other services offered by the Partnership relating to the Millennium
      Pipeline System.

            (h) "Agreement" means this Agreement of Limited Partnership as
      originally executed or as amended, modified, supplemented or restated from
      time to time.

            (i) "Allocation Year" means (i) the period commencing on the
      Effective Date and ending on December 31, 1998, (ii) any subsequent twelve
      (12) month period commencing on January 1 and ending on December 31 or
      (iii) any portion of the periods described in clauses (i) or (ii) for
      which the Partnership is required to allocate Profits, Losses and other
      items of Partnership income, gain, loss or deduction pursuant to Article 4
      hereof.

            (j) "Base Interest Rate" means a rate per annum equal to the lesser
      of (a) two percent (2%) plus the Prime Rate and (b) the maximum rate
      permitted by applicable law.


                                        2
<PAGE>   11
            (k) "Budget" means the annual operating budget or any other budget
      for the Partnership approved by the General Partner.

            (l) "Business Day" means any day other than a Saturday, Sunday or a
      holiday on which national banking associations in the State of New York
      are authorized to close.

            (m) "Capacity Lease and Exchange Agreement" means that certain
      Capacity Lease and Exchange Agreement to be entered into between the
      Partnership and Columbia for the lease of capacity on the Millennium
      Pipeline System on terms approved by the General Partner as the same may
      be amended or modified from time to time.

            (n) "Capital Account" means, with respect to any Partner, the
      Capital Account maintained for such Partner in accordance with the
      following provisions:

                  (i) To each Partner's Capital Account there shall be credited
            (A) such Partner's Capital Contributions, (B) that Partner's share
            of Profits and any items in the nature of income or gain which are
            specially allocated pursuant to Sections 4.01 and 4.03 hereof, and
            (C) the amount of any Partnership liabilities assumed by such
            Partner or which are secured by any Partnership Property distributed
            to such Partner; provided, however, that the principal amount of a
            promissory note which is not readily traded on an established
            securities market and which is contributed to the Partnership by the
            maker of the note (or a Partner related to the maker of the note
            within the meaning of Treasury Regulations Section
            1.704-1(b)(2)(ii)(c)) shall not be included in the Capital Account
            of any Partner until the Partnership makes a taxable disposition of
            the note or until (and to the extent) principal payments are made on
            the note, all in accordance with Treasury Regulations Section
            1.704-1(b)(2)(iv)(d)(2);

                  (ii) To each Partner's Capital Account there shall be debited
            (A) the amount of money and the Gross Asset Value of any Partnership
            Property distributed to such Partner pursuant to any provision of
            this Agreement, (B) such Partner's share of Losses and any items in
            the nature of expenses or losses which are specially allocated
            pursuant to Sections 4.02 or 4.03 hereof and (C) the amount of any
            liabilities of such Partner assumed by the Partnership or which are
            secured by any Partnership Property contributed by such Partner to
            the Partnership;

                  (iii) In the event Units are transferred in accordance with
            the terms of this Agreement, the transferee shall succeed to the
            Capital Account of the transferor in the same proportion as the
            Units so transferred; and

                  (iv) In determining the amount of any liability for purposes
            of subparagraphs (i) and (ii) above, there shall be taken into
            account Code Section 752(c) and any other applicable provisions of
            the Code and Treasury Regulations.


                                        3
<PAGE>   12
            The foregoing provisions and the other provisions of this Agreement
      relating to the maintenance of Capital Accounts are intended to comply
      with Treasury Regulations Section 1.704-1(b), and shall be interpreted and
      applied in a manner consistent with such Treasury Regulations. In the
      event the General Partner shall determine that it is prudent to modify the
      manner in which the Capital Accounts or any debits or credits thereto
      (including, without limitation, debits or credits relating to liabilities
      which are secured by contributed or distributed property or which are
      assumed by the Partnership or any Partner), are computed in order to
      comply with such Treasury Regulations, the General Partner may make such
      modification, provided that it is not likely to have a material effect on
      the amounts distributed to any Person pursuant to Article 10 hereof upon
      the dissolution of the Partnership. The General Partner also shall make
      (i) any adjustments that are necessary or appropriate to maintain equality
      between the Capital Accounts of the Partners and the amount of capital
      reflected on the Partnership's balance sheet, as computed for book
      purposes, in accordance with Treasury Regulations Section
      1.704-1(b)(2)(iv)(q), and (ii) any appropriate modifications in the event
      unanticipated events might otherwise cause this Agreement not to comply
      with Treasury Regulations Section 1.704-1(b).

            (o) "Capital Contribution" means the total amount of money and/or
      the initial Gross Asset Value of any property (net of any liabilities
      assumed or taken subject to) actually contributed to the Partnership by
      all of the Partners or any class of Partners or any one Partner, as the
      context requires. A Limited Partner's Capital Contribution includes its
      Initial Capital Contribution plus the amount of any Scheduled Capital
      Contributions or Additional Capital Contributions paid by the Limited
      Partner.

            (p) "Change in Control" means the Disposition of (i) a controlling
      interest in a Limited Partner to a Person that is not an Affiliate of the
      Limited Partner or Limited Partner Owner or (ii) a controlling interest in
      a Limited Partner Owner to a Person that is not an Affiliate of the
      Limited Partner Owner or the Limited Partner; provided, however, that
      Change in Control shall not include a Disposition of the interests of such
      Limited Partner Owner in the Millennium Pipeline System, held through the
      Limited Partner, which exceeds eighty percent (80%) of the value of such
      Limited Partner Owner. For purposes of this subsection 1.01(p)(ii), (A) a
      Disposition shall not include a mortgage, pledge, grant of a security
      interest or other disposition or encumbrance and (B) "controlling
      interest" shall mean possession, directly or indirectly, of power to
      direct or cause the direction of management or policies of a Person
      (whether through ownership of securities, partnership, limited liability
      company or other ownership interests by contract or otherwise).

            (q) "Code" means the Internal Revenue Code of 1986, as amended, or
      any successor statute thereto.

            (r) "Columbia" means Columbia Gas Transmission Corporation, a
      Delaware corporation.


                                       4
<PAGE>   13
            (s) "Commitment Voting Date" means the date on which the General
      Partner makes the determination to commit the Partnership to purchase all
      or substantially all of the pipe necessary to construct the Millennium
      Pipeline System or otherwise to commit to commence construction of the
      Millennium Pipeline System, taking into consideration factors established
      by the General Partner from time to time.

            (t) "Contribution Agreement" means that certain Contribution
      Agreement to be entered into between the Partnership and Columbia on terms
      and conditions approved by the General Partner pertaining to the
      contribution of assets by Columbia to the Partnership.

            (u) "Contribution Date" shall have the meaning set forth in
      subsection 3.03(c) hereof.

            (v) "Credit Support Documents" means documents executed by an
      Affiliate of a Limited Partner or other Person acceptable to the General
      Partner whereby the Affiliate or such other Person provides credit support
      for the obligations of such Limited Partner under this Agreement.

            (w) "Debt" means (i) any indebtedness for borrowed money or the
      deferred purchase price of property as evidenced by a note, bond or other
      instrument, (ii) obligations as lessee under capital leases, (iii)
      obligations secured by any mortgage, pledge, security interest,
      encumbrance, lien or charge of any kind existing on any asset owned or
      held by the Partnership whether or not the Partnership has assumed or
      become liable for the obligations secured thereby, (iv) any net obligation
      under any interest rate swap agreement, (v) accounts payable and (vi)
      obligations under direct or indirect guarantees of (including obligations
      (contingent or otherwise) to assure a creditor against loss in respect of)
      indebtedness or obligations of the kinds referred to in clauses (i), (ii),
      (iii), (iv) and (v), above, provided that Debt shall not include
      obligations in respect of any accounts payable that are incurred in the
      ordinary course of the Company's business and are either not delinquent or
      are being contested in good faith by appropriate proceedings.

            (x) "Delinquent Partner" shall have the meaning set forth in Section
      3.04 hereof.

            (y) "Depreciation" means, for each Allocation Year, an amount equal
      to the depreciation, amortization, or other cost recovery deduction
      allowable with respect to an asset for such Allocation Year, except that,
      if the Gross Asset Value of an asset differs from its adjusted basis for
      federal income tax purposes at the beginning of such Allocation Year,
      Depreciation shall be an amount which bears the same ratio to such
      beginning Gross Asset Value as the federal income tax depreciation,
      amortization or other cost recovery deduction for such Allocation Year
      bears to such beginning adjusted tax basis; provided, however, that if the
      adjusted basis for federal income tax purposes of an asset at the
      beginning of such Allocation Year is zero, Depreciation shall be
      determined with reference to such beginning Gross Asset Value using any
      reasonable method selected by the General Partner.


                                       5
<PAGE>   14
            (z) "Dispose," "Disposing" or "Disposition" shall each mean a sale,
      assignment, transfer, exchange, mortgage, pledge, grant of a security
      interest or other disposition or encumbrance (including without
      limitation, by operation of law).

            (aa) "Dispute" shall have the meaning set forth in Section 12.01
      hereof.

            (bb) "Effective Date" means the last to occur of (i) the date this
      Agreement is executed and adopted by all of the parties hereto and (ii)
      the date the Partnership's Certificate of Limited Partnership is filed
      with the Secretary of State of the State of Delaware.

            (cc) "FERC" means the Federal Energy Regulatory Commission or any
      commission, agency or other governmental body succeeding to the power of
      such commission under the Natural Gas Act.

            (dd) "General Interest Rate"means a rate per annum equal to the
      lesser of (i) one percent (1%) plus the Prime Rate and (ii) the maximum
      rate permitted by applicable law.

            (ee) "General Partner" means Millennium Pipeline Management Company,
      L.L.C., a Delaware limited liability company. The term "General Partner"
      also includes any other Person who is duly admitted to the Partnership as
      an additional or substitute general partner.

            (ff) "Gross Asset Value" means, with respect to any asset, the
      asset's adjusted basis for federal income tax purposes, except as follows:

                  (i) The initial Gross Asset Value of any asset contributed by
            a Partner to the Partnership shall be the gross fair market value of
            such asset as determined by the General Partner;

                  (ii) The Gross Asset Values of all Partnership assets shall be
            adjusted to equal their respective gross fair market values (taking
            Code Section 7701(g) into account on the date determined), as
            determined by the General Partner as of the following times: (A) the
            acquisition of an additional interest in the Partnership by any new
            or existing Partner in exchange for more than a de minimis Capital
            Contribution; (B) the distribution by the Partnership to a Partner
            of more than a de minimis amount of Partnership Property as
            consideration for an interest in the Partnership; provided that
            either or both adjustments described in clauses (A) and (B) of this
            paragraph shall be made only if the General Partner reasonably
            determine that such adjustment is necessary to reflect the relative
            economic interests of the Partners in the Partnership;

                  (iii) The Gross Asset Value of any item of Partnership assets
            distributed to any Partner shall be adjusted to equal the gross fair
            market value (taking Code Section 7701(g) into account) of such
            asset on the date of distribution as determined by the General
            Partner; and


                                       6
<PAGE>   15
                  (iv) The Gross Asset Values of Partnership assets shall be
            increased (or decreased) to reflect any adjustments to the adjusted
            basis of such assets pursuant to Code Sections 734(b) or 743(b), but
            only to the extent that such adjustments are taken into account in
            determining Capital Accounts pursuant to Treasury Regulations
            Section 1.704-1(b)(2)(iv)(m) and subparagraph (vi) of the definition
            of "Profits" and "Losses" or Section 4.02(c) hereof; provided,
            however, that Gross Asset Values shall not be adjusted pursuant to
            this subparagraph (iv) to the extent that an adjustment pursuant to
            subparagraph (ii) of this subsection (ff) is required in connection
            with a transaction that would otherwise result in an adjustment
            pursuant to this subparagraph (iv).

      If the Gross Asset Value of an asset has been determined or adjusted
      pursuant to subparagraph (ii) or (iv) above, such Gross Asset Value shall
      thereafter be adjusted by the Depreciation taken into account with respect
      to such asset for purposes of computing Profits and Losses.

            (gg) "Initial Capital Contributions" means the amount in cash to be
      contributed to the capital of the Partnership pursuant to Articles 2 and 3
      hereto by all the Partners, the Limited Partners, the General Partner, or
      any one Partner, as the context requires.

            (hh) "In-Service Date" shall have the meaning set forth in
      subsection 7.03(c) hereof.

            (ii) "Interest" means the entire ownership interest of a Partner in
      the Partnership at any particular time as a General Partner or a Limited
      Partner holding Units, including, but not limited to, the right of such
      Partner to any and all rights and benefits to which a Partner is entitled
      pursuant to the terms of this Agreement. The initial Interest of each
      Partner shall be as set forth on Exhibit A hereto. The Interest of each
      Partner shall be adjusted from time to time (i) based upon the Capital
      Contributions made by the Partners in accordance with Article 3 hereto,
      with the Interest of each Partner being equal to a fraction, the numerator
      of which is a Partner's cumulative Capital Contribution and the
      denominator of which is the cumulative total of all Partner's Capital
      Contributions; and (ii) upon the withdrawal of a Limited Partner, in which
      case the Interest of the Withdrawing Limited Partner shall, as of the
      Withdrawal Effective Date, be distributed pro rata among all of the
      non-withdrawing Partners in a portion equal to the ratio of (A) the
      pre-withdrawal Interest of such non-withdrawing Partner to (B) the sum of
      all pre-withdrawal Interests of all non-withdrawing Partners.

            (jj) "Lake Crossing Agreement" means that certain Lake Crossing
      Agreement to be entered into between TransCanada PipeLines Limited or an
      Affiliate thereof and Columbia in its capacity as the project developer
      under the Project Development Agreement, on terms approved by the General
      Partner, relating to the construction of the segment of the Millennium
      Pipeline System which will pass under Lake Erie.


                                       7
<PAGE>   16
            (kk) "Limited Partner" means any Person who is admitted to the
      Partnership as a limited partner pursuant to the terms of this Agreement,
      including the Persons executing this Agreement as "Limited Partners."

            (ll) "Limited Partner Owner" means the Person or Persons that own,
      of record or beneficially, all of the capital stock or equity interests in
      a Limited Partner.

            (mm) "Liquidator" shall have the meaning set forth in Section 10.04
      hereof.

            (nn) "Losses" shall have the meaning set forth in Section 1.01(ddd)
      hereof.

            (oo) "Millennium Pipeline System" shall have the meaning set forth
      in the Preamble to this Agreement.

            (pp) "MOU" means that certain Memorandum of Understanding dated as
      of December 1, 1997, among Columbia, Westcoast Energy (U.S.), Inc., MCN
      Investment Corporation and TransCanada PipeLines Limited, as amended,
      modified and extended.

            (qq) "Net Cash Flow" means the gross cash revenues of the
      Partnership less the portion thereof used to pay or establish working
      capital reserves for all Partnership expenses, debt payments, capital
      improvements, replacements and contingencies, all as determined by the
      General Partner; provided, however, that Net Cash Flow shall not be
      reduced by depreciation, amortization, cost recovery deductions or similar
      allowances, but shall be increased by any reductions of reserves
      previously established pursuant to the first clause of this definition.

            (rr) "Nonrecourse Deductions" shall have the meaning set forth in
      Section 1.704- 2(b)(1) of the Treasury Regulations.

            (ss) "Nonrecourse Liability" shall have the meaning set forth in
      Section 1.704- 2(b)(3) of the Treasury Regulations.

            (tt) "O&M Agreement" means that certain Operations, Maintenance and
      Management Services Agreement to be entered into between the Partnership
      and Columbia on terms and conditions acceptable to the General Partner
      relating to the operation, maintenance and management of the Millennium
      Pipeline System.

            (uu) "Partner Nonrecourse Debt" shall have the same meaning as the
      term "partner nonrecourse debt" set forth in Section 1.704-2(b)(4) of the
      Treasury Regulations.

            (vv) "Partner Nonrecourse Debt Minimum Gain" means an amount, with
      respect to each Partner Nonrecourse Debt, equal to the Partnership Minimum
      Gain that would result if such Partner Nonrecourse Debt were treated as
      nonrecourse as determined in accordance with Section 1.704-2(i)(3) of the
      Treasury Regulations.


                                       8
<PAGE>   17
            (ww) "Partner Nonrecourse Deductions" shall have the same meaning as
      the term "partner nonrecourse deductions" set forth in Sections
      1.704-2(i)(1) and 1.704-2(i)(2) of the Treasury Regulations.

            (xx) "Partners" means the General Partner and the Limited Partners
      who are admitted as partners in the Partnership, unless otherwise
      indicated.

            (yy) "Partnership" means Millennium Pipeline Company, L.P., a
      Delaware limited partnership, as the Partnership may be constituted from
      time to time.

            (zz) "Partnership Property" means all interests, properties and
      rights of any type, whether real, personal, tangible or intangible, owned
      by the Partnership.

            (aaa) "Person" means a natural person, partnership (whether general
      or limited and whether domestic or foreign), trust, estate, association,
      corporation, custodian, nominee or any other individual or entity in its
      own or any representative capacity.

            (bbb) "Precedent Agreements" means the Precedent Agreements entered
      into on behalf of the Partnership with proposed customers of the
      Partnership for the transmission of natural gas through the Millennium
      Pipeline System.

            (ccc) "Prime Rate" means the fluctuating per annum rate of interest
      announced from time to time by Citibank, N.A. as its "Prime Rate."

            (ddd) "Profits" and "Losses" mean, for each Allocation Year, an
      amount equal to the Partnership's taxable income or loss for such
      Allocation Year, determined in accordance with Code Section 703(a) (for
      purposes of such determination, all items of income, gain, loss or
      deduction required to be stated separately pursuant to Code Section
      703(a)(1) shall be included in taxable income or loss), with the following
      adjustments (without duplication):

                  (i) Any income of the Partnership exempt from federal income
            tax and not otherwise taken into account in computing Profits or
            Losses pursuant to this definition of "Profits" and "Losses" shall
            be added to such taxable income or loss;

                  (ii) Any expenditures of the Partnership described in Code
            Section 705(a)(2)(B) or treated as Code Section 705(a)(2)(B)
            expenditures pursuant to Treasury Regulations Section
            1.704-1(b)(2)(iv)(i) and not otherwise taken into account in
            computing Profits or Losses pursuant to this definition of "Profits"
            and "Losses" shall be subtracted from such taxable income or loss;

                  (iii) In the event the Gross Asset Value of any Partnership
            asset is adjusted pursuant to subparagraphs (ii) or (iii) of the
            definition of Gross Asset Value, the amount of such adjustment shall
            be treated as an item of gain (if the adjustment increases the Gross
            Asset Value of the asset) or an item of loss (if the adjustment


                                       9
<PAGE>   18
            decreases the Gross Asset Value of the asset) from the disposition
            of such asset and shall be taken into account for purposes of
            computing Profits or Losses;

                  (iv) Gain or loss resulting from any Disposition of
            Partnership Property with respect to which gain or loss is
            recognized for federal income tax purposes shall be computed by
            reference to the Gross Asset Value of the Partnership Property
            Disposed of, notwithstanding that the adjusted tax basis of such
            Partnership Property differs from its Gross Asset Value;

                  (v) In lieu of the depreciation, amortization and other cost
            recovery deductions taken into account in computing such taxable
            income or loss, there shall be taken into account Depreciation for
            such Allocation Year, computed in accordance with the definition of
            Depreciation;

                  (vi) To the extent an adjustment to the adjusted tax basis of
            any Partnership asset pursuant to Code Section 734(b) is required,
            pursuant to Treasury Regulations Section 1.704-1(b)(2)(iv)(m)(4), to
            be taken into account in determining Capital Accounts as a result of
            a distribution other than in liquidation of a Partner's Interest,
            the amount of such adjustment shall be treated as an item of gain
            (if the adjustment increases the basis of the asset) or loss (if the
            adjustment decreases such basis) from the disposition of such asset
            and shall be taken into account for purposes of computing Profits or
            Losses; and

                  (vii) Notwithstanding any other provision of this definition,
            any items which are specially allocated pursuant to Sections 4.02 or
            4.03 hereof shall not be taken into account in computing Profits or
            Losses.

            The amounts of the items of Partnership income, gain, loss or
      deduction available to be specially allocated pursuant to Sections 4.02
      and 4.03 hereof shall be determined by applying rules analogous to those
      set forth in subparagraphs (i) through (vi) above.

            (eee) "Project Agreements" means the Capacity Lease and Exchange
      Agreement, the Contribution Agreement, the Lake Crossing Agreement, the
      O&M Agreement, the Project Development Agreement, and the Precedent
      Agreements, as the same may be amended and modified from time to time.

            (fff) "Project Development Agreement" means that certain Project
      Development and Management Services Agreement to be entered into between
      the Partnership and Columbia on terms and conditions acceptable to the
      General Partner relating to the construction and development of the
      Millennium Pipeline System.

            (ggg) "PUHCA" means the Public Utility Holding Company Act of 1935,
      as amended.


                                       10
<PAGE>   19
            (hhh) "PUHCA Company" shall have the meaning set forth in Section
      6.10 hereof.

            (iii) "Regulatory Allocations" shall have the meaning set forth in
      Section 4.04 hereof.

            (jjj) "Required Accounting Practices" means generally accepted
      accounting principles as practiced in the United States at the time
      prevailing for companies engaged in a business similar to the Partnership
      or, if inconsistent therewith, the accounting rules and regulations, if
      any, at the time prescribed by the regulatory body or bodies under the
      jurisdiction of which the Partnership is at the time operating.

            (kkk) "Required Interest" means a majority of the Interests of
      Partners that are not Withdrawing Limited Partners or Abstaining Partners.

            (lll) "Sale Notice" shall have the meaning set forth in subsection
      6.05(a).

            (mmm) "Scheduled Capital Contributions" shall have the meaning set
      forth in Section 3.03 hereto.

            (nnn) "Substitute Limited Partner" means any Person admitted to the
      Partnership as a Limited Partner pursuant to the provisions of Section
      6.04(c) hereof.

            (ooo) "System Modification" shall mean any facilities to be
      installed or action to be taken costing in excess of One Million Dollars
      (US$1,000,000) to modify, improve, expand or increase the capacity of the
      Millennium Pipeline System or any portion thereof after the Commitment
      Voting Date (except in connection with customary maintenance and except
      for modifications which in the reasonable judgment of the General Partner
      (a) do not result in an expansion of the capacity or a change in the
      essential design of the Millennium Pipeline System or (b) are necessary to
      comply with applicable environmental or safety requirements).

            (ppp) "Treasury Regulations" means the Income Tax Regulations,
      including Temporary Regulations, promulgated under the Code, as such
      regulations are issued, supplemented and amended from time to time.

            (qqq) "UCC" means the Uniform Commercial Code of the State of
      Delaware, as amended from time to time.

            (rrr) "Unanimous Consent" means the consent of all Partners holding
      an Interest in the Partnership who are not Withdrawing Limited Partners or
      Abstaining Partners.

            (sss) "Unit" means any one of the general or limited partnership
      interests issued in the following classes:


                                       11
<PAGE>   20
                  (i) Limited Partner Units -- Nine thousand nine hundred
            (9,900) Units each issued in exchange for an Initial Capital
            Contribution as set forth in Section 2.08(b) hereof, each
            representing a 0.01% interest in the Partnership for an aggregate
            Partnership interest for all Limited Partner Units of ninety-nine
            percent (99%);

                  (ii) General Partner Units -- One hundred (100) General
            Partner Units issued in exchange for the General Partner's Capital
            Contribution as set forth in Section 2.08(c) hereof, each
            representing a 0.01% interest in the Partnership for an aggregate
            Partnership interest for all General Partner Units of one percent
            (1%).

            (ttt) "Withdrawal Effective Date" shall have the meaning set forth
      in subsection 7.03(a) hereof.

            (uuu) "Withdrawal Notice" shall have the meaning set forth in
      Section 7.03(a) hereof.

            (vvv) "Withdrawal Period" shall have the meaning set forth in
      Section 7.04 hereof.

            (www) "Withdrawing Limited Partner" shall have the meaning set forth
      in Section 7.03(a) hereof.

      Additional terms defined in other sections of this Agreement have the
meanings given them in such sections throughout this Agreement.

      1.02 Construction. The headings in this Agreement are inserted for
convenience of reference only and shall not affect interpretation of this
Agreement. Whenever the context requires, each term stated in either the
singular or the plural shall include the singular and the plural, and the gender
of all words used in this Agreement includes the masculine, the feminine and the
neuter. Except as otherwise noted, references to Articles and Sections refer to
articles and sections of this Agreement, and all references to Exhibits are to
exhibits attached hereto, each of which is made a part hereof for all purposes.
Use of the word "including" shall mean without limitation by reason of
enumeration.

                                  ARTICLE 2

                                 ORGANIZATION

      2.01 Formation. For and in consideration of the agreements contained
herein, the parties hereto agree to form and do hereby form a limited
partnership under the Act. The rights, duties and liabilities of the Partners
shall be as provided in the Act, except as otherwise provided herein.


                                       12
<PAGE>   21
      2.02 Name. The name of the Partnership shall be "Millennium Pipeline
Company, L.P.," or such other name or names as the General Partner may from time
to time deem necessary, appropriate or advisable.

      2.03 Registered Agent and Registered Office. The initial registered agent
of the Partnership in the State of Delaware shall be The Corporation Trust
Company and the initial registered office of the Partnership shall be located at
1209 Orange, Wilmington, Delaware 19801. The General Partner may from time to
time change the registered agent or registered office of the Partnership, or
both. The General Partner shall promptly notify all other Partners of any change
in the registered office or registered agent of the Partnership.

      2.04 Location of Principal Place of Business. The principal place of
business of the Partnership shall be 12801 Fair Lakes Parkway, Fairfax, Virginia
22030, or such other place as the General Partner may from time to time
designate in writing to the Limited Partners. The Partnership may maintain such
other offices at such other places as the General Partner deems advisable.

      2.05 Business and Purpose. The business and purpose of the Partnership
shall be to design, develop, construct, own and operate a natural gas
transmission system extending from an interconnection with a natural gas
transmission system to be owned and operated by TransCanada PipeLines Limited at
the border between the United States and Canada in Lake Erie to a terminus in
Westchester County, New York, and to engage in any other business or activity
that now or hereafter may be necessary, incidental, proper, advisable or
convenient to accomplish the foregoing purpose that is not forbidden by the law
of the jurisdiction in which the Partnership engages in that business. The
business and purpose of the Partnership shall additionally encompass any
activities contemplated by the rights and powers of the General Partner
described in this Agreement to the extent not specifically set forth in this
Section 2.05.

      2.06 Term. The Partnership's existence shall commence on the Effective
Date and shall continue until the Partnership terminates pursuant to Article 10
hereof, following dissolution.

      2.07 Filing of Certificates. The General Partner shall execute, file and
publish all such certificates, notices, statements or other instruments required
by law for the formation or operation of a limited partnership in all
jurisdictions where the Partnership may propose to do business. The General
Partner may amend the Certificate of Limited Partnership from time to time for
any proper purpose.

      2.08 General and Original Limited Partners' Units and Interests.

            (a) The General Partner has accepted Capital Contributions from the
      Limited Partners consisting of the total amount of money and/or property
      as set forth on Exhibit A hereto.

            (b) The original Limited Partners and the respective Units, Interest
      and the Initial Capital Contribution of each Limited Partner shall be as
      set forth on Exhibit A hereto.


                                       13
<PAGE>   22
            (c) Millennium Pipeline Management Company, L.L.C., shall be the
      initial sole General Partner and shall make the Initial Capital
      Contribution set out on Exhibit A hereto. The General Partner shall
      receive in exchange for such Initial Capital Contribution one hundred
      (100) General Partner Units representing an aggregate Interest in the
      Partnership of one percent (1%).

            (d) All Units in the aggregate shall have a one hundred percent
      (100%) interest in the Partnership.

      2.09 Additional Limited Partners. A Person other than the original Limited
Partners shall become a Limited Partner only if (a) such Person executes and
delivers to the General Partner an amendment to this Partnership Agreement
together with any other documentation that may be required of a prospective
Limited Partner by the General Partner, including, without limitation, Credit
Support Documents and (b) such amendment to this Partnership Agreement is
executed and accepted by the General Partner.

      2.10 Organization Certificates. Upon the request of the General Partner,
each Limited Partner agrees to execute and deliver from time to time all
certificates and other documents deemed necessary by the General Partner to
accomplish all filing, recording, publishing and other acts appropriate to
comply with all requirements for the formation, qualification and operation of
(a) a limited partnership under the Act and (b) a limited partnership, or a
partnership in which the limited partners have limited liability, in all other
jurisdictions where the Partnership shall propose to conduct business.

      2.11 Power of Attorney.

            (a) Each Limited Partner hereby irrevocably designates and appoints
      the General Partner, its successors and assigns, each with full power of
      substitution, his agent and attorney-in-fact in his name, place and stead
      to (i) do any acts necessary to qualify the Partnership to do business
      under the laws of any jurisdiction in which it is necessary or advisable
      to file any instrument in writing in connection with such qualification
      and (ii) consent to, make, execute, swear to and acknowledge, amend, file,
      record, deliver and publish: (1) any certificate of limited partnership or
      amended certificate of limited partnership under the Act and any other
      certificates, either original or amended, required or permitted to be
      filed or recorded under statutes relating to limited partnerships under
      the laws of any jurisdiction in which the Partnership shall engage or seek
      to engage in business; (2) a counterpart of or amendment to this Agreement
      for the purpose of substituting as a Limited Partner an assignee or
      successor to all or any portion of a Limited Partner's Interest pursuant
      to this Agreement; (3) a counterpart of this Agreement or of any amendment
      hereto for the purpose of filing or recording such counterpart in any
      jurisdiction in which the Partnership may own property or transact
      business; (4) all certificates and other instruments necessary to qualify
      or continue the Partnership as a limited partnership or partnership
      wherein the Limited Partners have limited liability in any jurisdiction
      where the Partnership may own property or be doing business; (5) any
      fictitious or assumed name certificate required or permitted to


                                       14
<PAGE>   23
      be filed by or on behalf of the Partnership; (6) any other instrument
      which is now or which may hereafter be required by law to be filed for or
      on behalf of the Partnership or its Partners with respect to Partnership
      business; (7) certificates or other instruments evidencing the dissolution
      or termination of the Partnership when such shall be appropriate in each
      jurisdiction in which the Partnership shall own property or do business;
      (8) any amendment to this Agreement adopted pursuant to the applicable
      provisions of this Agreement; and (9) a counterpart of or amendment to
      this Agreement for the purpose of admitting or removing a Person as a
      Partner pursuant to this Agreement (including, but not limited to, the
      provisions of Section 6.04 hereof).

            (b) Each Limited Partner hereby agrees to execute and deliver to the
      General Partner within ten (10) days after receipt of a written request
      therefor such other and further statements of interest and holdings,
      designations, powers of attorney and other instruments as the General
      Partner deems necessary or advisable to conduct the business of the
      Partnership. The power of attorney granted herein is hereby declared
      irrevocable and a power coupled with an interest, and shall (i) survive
      the bankruptcy, disability or death of a Limited Partner, if an
      individual, or the bankruptcy, dissolution or other termination of a
      Limited Partner, if a corporation, trust, partnership or unincorporated
      association, and (ii) extend to and be binding upon such Limited Partner's
      legal representatives, heirs, successors and assigns. Each Limited Partner
      hereby agrees to be bound by any representations made by the General
      Partner acting pursuant to such power of attorney, and each Limited
      Partner hereby waives any and all defenses which may be available to
      contest, negate or disaffirm any action of the General Partner except in
      cases of willful misconduct.


                                    ARTICLE 3

                          CAPITALIZATION AND FINANCING

      3.01 Commencement of Operations. The Partnership shall commence operations
on the Effective Date.

      3.02 Initial Capital Contributions. The Initial Capital Contributions of
the Partners shall be as set forth on Exhibit A attached hereto, which shall
include amounts contributed by the Limited Partners or their Affiliates for the
development of the Millennium Pipeline System pursuant to the terms of the MOU.

      3.03  Scheduled and Additional Capital Contributions.

            (a) The Partners agree to contribute to the Partnership, upon the
      request of the General Partner, the capital determined to be necessary
      from time to time by the General Partner to fund expenditures approved in
      any Budget (the "Scheduled Capital Contributions"). It is expressly
      acknowledged and agreed by the Partners that Columbia will be contributing
      certain assets to the Partnership as part of its Scheduled Capital
      Contributions, the value of which shall be determined by the General
      Partner. In addition,


                                       15
<PAGE>   24
      the General Partner may request Additional Capital Contributions that, in
      the judgment of the General Partner, are necessary to enable the
      Partnership to cause the assets of the Partnership to be properly
      developed, operated and maintained and to discharge its costs, expenses,
      obligations and liabilities. Additional Capital Contributions may be
      requested from time to time and at any time during the term of the
      Partnership in such amounts as estimated in good faith by the General
      Partner.

            (b) Additional Capital Contributions may be requested by the General
      Partner in one or more requests. Each Limited Partner shall cause payment
      for each respective Additional Capital Contribution to be actually
      received in hand, in cash, by the General Partner within twenty (20) days
      after the notice of the Additional Capital Contribution is deemed to have
      been given to the Limited Partner in accordance with Section 13.02 hereof.

            (c) Each request for a Scheduled Capital Contribution or an
      Additional Capital Contribution shall specify the Limited Partner's
      proportionate share of the amount required, a summary of the intended use
      of the proceeds and the date such Scheduled Capital Contribution or
      Additional Contribution is due (the "Contribution Date").

      3.04 Failure to Contribute. If a Limited Partner fails to contribute all
or any portion of a Capital Contribution that the Limited Partner is required to
make by the Contribution Date as provided in this Agreement (becoming a
"Delinquent Partner") and such failure continues for sixty (60) days from the
date such Capital Contribution is scheduled to be made, then the Delinquent
Partner shall be deemed to be a Withdrawing Limited Partner pursuant to Section
7.03 hereof, effective as of the end of such sixty (60) day period; provided,
however, a Delinquent Partner shall not be entitled to (i) a return of any
Capital Contribution (and shall forfeit the same) and (ii) the indemnification
provided pursuant to Section 7.04 hereof. Throughout any period during which a
Limited Partner is a Delinquent Partner, the delinquent Capital Contribution, or
any delinquent portion thereof, shall bear interest at a rate per annum equal to
the lesser of (x) the sum of the Prime Rate plus five percent (5%) and (y) the
maximum rate permitted by applicable law from the Contribution Date until the
date the Capital Contribution is received by the Partnership.

      3.05 Partnership Borrowing.

            (a) The General Partner may cause the Partnership to borrow money
      from time to time, from third parties or from the General Partner, and may
      mortgage or pledge Partnership Property to obtain and secure the repayment
      of such loans. The proceeds of Partnership loans may be used for any
      Partnership purpose, including the payment of the costs and expenses
      related to expenses of the Partnership, to refinance Partnership
      indebtedness, or to pay costs that would have otherwise been paid by
      Capital Contributions. The General Partner may cause the Partnership to
      mortgage or pledge Partnership Properties to secure loans the proceeds of
      which will be applied to benefit Partnership Properties.

            (b) The General Partner may cause the Partnership to borrow from
      third parties or the General Partner. The General Partner is not, however,
      obligated to lend funds to the


                                       16
<PAGE>   25
      Partnership. If the General Partner loans money to the Partnership, it
      will receive interest at the Base Interest Rate. The General Partner may
      secure loans made by it to the Partnership by mortgages or pledges of
      Partnership Property. Loans by the General Partner to the Partnership
      shall be treated as indebtedness to a non-Partner lender and will be
      payable prior to any distributions to the Limited Partners.

      3.06 Additional Financing. No Limited Partner shall be required to make
any contribution to the capital of the Partnership other than (a) its Initial
Capital Contribution, (b) its Scheduled Capital Contributions, (c) its share of
Additional Capital Contributions and (d) any amounts required to be paid to or
for the benefit of the Partnership pursuant to Section 13.01 hereof. This
provision shall not be deemed a limitation, however, on the General Partner's
right to cause the Partnership to borrow or to retain, use or pledge so much of
the undistributed revenues and other assets of the Partnership as in its opinion
may be required to provide for the Partnership's anticipated future cash needs
(including contingencies), or to repay amounts borrowed.

      3.07 Revenues. Any or all revenues received by the Partnership may be
accumulated and retained in the Partnership for any Partnership purpose
including, but not limited to, the costs of partnership expenses or the
repayment of borrowing by the Partnership. The extent to which the Partnership
accumulates or expends its revenues will be determined in the sole discretion of
the General Partner.

      3.08 Partnership Capital.

            (a) No interest shall be paid by the Partnership on any Capital
      Contributions or Capital Account balances, except as may be specifically
      provided in this Agreement.

            (b) No Partner shall have the right to withdraw any part of its
      Capital Contribution or Capital Account, or to receive any return of any
      portion of its Capital Contribution or its Capital Account, except as may
      be specifically provided in this Agreement.

            (c) Under circumstances involving a return of any Capital
      Contribution, no Partner shall have the right to receive property other
      than cash, except as may be specifically provided in this Agreement.

            (d) Loans from any Partner to the Partnership shall not be
      considered Capital Contributions.

            (e) A Partner shall not be required to contribute or to lend any
      cash or property to the Partnership to enable the Partnership to return
      any Partner's Capital Contributions.

      3.09 Advances by Partners. If the Partnership does not have sufficient
cash to pay its obligations, any Partner(s) that may agree to do so may advance
all or part of the needed funds to or on behalf of the Partnership (provided the
Partner has made its Capital Contribution). An advance


                                       17
<PAGE>   26
described in this Section 3.09 constitutes a loan from the Partner to the
Partnership, bears interest at the General Interest Rate from the date of the
advance until the date of payment and is not a Capital Contribution. Approval of
the terms of any loan to the Partnership by a Partner shall be determined by
majority vote of all Limited Partners that are not lenders in the transaction
under consideration plus the approval of the General Partner.

      3.10 Capital Accounts. Each Partner shall have a capital account with a
balance maintained in accordance with the definition of "Capital Account" in
Section 1.01(k) hereof.

      3.11 Capital Contributions for System Modifications. No Partner shall have
any obligation to make Additional Capital Contributions requested for the
purpose of funding the costs of a System Modification unless the Partner has
voted in favor of such System Modification. It is the intent of the Partners
that the Partners' Interests shall be adjusted to reflect the Interest of each
Partner immediately after Additional Capital Contributions are made relating to
the costs of any System Modifications. A Partner that votes against a System
Modification shall not be permitted to make Capital Contributions for such
System Modification unless the Partners voting in favor of the System
Modification unanimously consent to such contribution.

                                    ARTICLE 4

                          ALLOCATIONS AND DISTRIBUTIONS

      4.01 Profits. After giving effect to the special allocations set forth in
Sections 4.03 and 4.04 hereof, Profits for any Allocation Year shall be
allocated as follows:

            (a) First, to each Partner in an amount equal to the excess, if any,
      of (i) the cumulative Losses allocated to such Partner pursuant to Section
      4.02(a) hereof for all prior Allocation Years, over (ii) the cumulative
      Profits allocated to the Partners pursuant to this Section 4.01(a) for all
      prior Allocation Years; and

            (b) The balance, if any, to the Partners in proportion to their
      interests.

      All revenues used to repay any principal, interest or other amounts owing
with respect to Partnership borrowings or indebtedness shall be allocated to the
Partners in the same proportions that the costs paid with the proceeds of such
borrowings or indebtedness were allocated to the Partners and, with respect to
any indebtedness to which any property acquired by the Partnership was subject
at the time of its acquisition, in the same proportions as the costs of
acquisition of such property were allocated.

      4.02 Losses. After giving effect to the special allocations set forth in
Sections 4.03 and 4.04 hereof, Losses for any Allocation Year shall be allocated
as follows:

            (a) Among the Partners in proportion to their Interests, provided
      that Losses shall not be allocated pursuant to this Section 4.02(a) to the
      extent such allocation would cause


                                       18
<PAGE>   27
      any Partner to have an Adjusted Capital Account Deficit at the end of such
      Allocation Year; and

            (b) The balance, if any, to the General Partner.

      4.03 Special Federal Income Tax Allocations. The following special
allocations shall be made in the following order:

            (a) Minimum Gain Chargeback. Except as otherwise provided in Section
      1.704-2(f) of the Treasury Regulations, notwithstanding any other
      provisions of this Article 4, if there is a net decrease in Partnership
      Minimum Gain during any Allocation Year, each Partner shall be specially
      allocated items of Partnership income and gain for such Allocation Year
      (and, if necessary, subsequent Allocation Years) in an amount equal to
      such Partner's share of the net decrease in Partnership Minimum Gain,
      determined in accordance with Treasury Regulations Section 1.704-2(g).
      Allocations pursuant to the previous sentence shall be made in proportion
      to the respective amounts required to be allocated to each Partner
      pursuant thereto. The items to be so allocated shall be determined in
      accordance with Sections 1.704-2(f) (6) and 1.704-2(j)(2) of the Treasury
      Regulations. This Section 4.03(a) is intended to comply with the minimum
      gain chargeback requirement in Section 1.704-2(f) of the Treasury
      Regulations and shall be interpreted consistently therewith.

            (b) Partner Minimum Gain Chargeback. Except as otherwise provided in
      Section 1.704-2(i)(4) of the Treasury Regulations, notwithstanding any
      other provision of this Article 4, if there is a net decrease in Partner
      Nonrecourse Debt Minimum Gain attributable to a Partner Nonrecourse Debt
      during any Allocation Year, each Partner who has a share of the Partner
      Nonrecourse Debt Minimum Gain attributable to such Partner Nonrecourse
      Debt, determined in accordance with Section 1.704-2(i)(5) of the Treasury
      Regulations, shall be specially allocated items of Partnership income and
      gain for such Allocation Year (and, if necessary, subsequent Allocation
      Years) in an amount equal to such Partner's share of the net decrease in
      Partner Nonrecourse Debt, determined in accordance with Treasury
      Regulations Section 1.704-2(i)(4). Allocations pursuant to the previous
      sentence shall be made in proportion to the respective amounts required to
      be allocated to each Partner pursuant thereto. The items to be so
      allocated shall be determined in accordance with Sections 1.704-2(i)(4)
      and 1.704-2(j)(2) of the Treasury Regulations. This Section 4.03(b) is
      intended to comply with the minimum gain chargeback requirement in Section
      1.704-2(i)(4) of the Treasury Regulations and shall be interpreted
      consistently therewith.

            (c) Qualified Income Offset. In the event any Partner unexpectedly
      receives any adjustments, allocations or distributions described in
      Sections 1.704-1(b)(2)(ii)(d)(4), 1.704-1(b)(2)(ii)(d)(5) or
      1.704-1(b)(2)(ii)(d)(6) of the Treasury Regulations, items of Partnership
      income and gain shall be specially allocated to such Partner in an amount
      and manner sufficient to eliminate, to the extent required by the Treasury
      Regulations, the Adjusted Capital Account Deficit of the Partner as
      quickly as possible, provided that an


                                       19
<PAGE>   28
      allocation pursuant to this Section 4.03(c) shall be made only if and to
      the extent that the Partner would have an Adjusted Capital Account Deficit
      after all other allocations provided for in this Article 4 have been
      tentatively made as if this Section 4.03(c) were not in this Agreement.

            (d) Nonrecourse Deductions. Nonrecourse Deductions for any
      Allocation Year shall be specially allocated to the Partners in proportion
      to their respective Units.

            (e) Partner Nonrecourse Deductions. Any Partner Nonrecourse
      Deductions for any Allocation Year shall be specially allocated to the
      Partner(s) who bear the economic risk of loss with respect to the Partner
      Nonrecourse Debt to which such Partner Nonrecourse Deductions are
      attributable in accordance with Treasury Regulations Section 
      1.704-2(i)(1).

            (f) Section 754 Adjustments. To the extent an adjustment to the
      adjusted tax basis of any Partnership asset, pursuant to Code Section
      734(b) or Code Section 743(b) is required, pursuant to Treasury
      Regulations Section 1.704-1(b)(2)(iv)(m)(2) or 1.704-1(b)(2)(iv)(m)(4), to
      be taken into account in determining Capital Accounts as the result of a
      distribution to a Partner in complete liquidation of such Partner's
      Interest, the amount of such adjustment to Capital Accounts shall be
      treated as an item of gain (if the adjustment increases the basis of the
      asset) or loss (if the adjustment decreases such basis) and such gain or
      loss shall be specially allocated to the Partners in accordance with their
      interests in the Partnership in the event Treasury Regulations Section
      1.704-1(b)(2)(iv)(m)(2) applies, or to the Partner to whom such
      distribution was made in the event Treasury Regulations Section
      1.704-1(b)(2)(iv)(m)(4) applies.

      4.04 Curative Allocations. The allocations set forth in Sections 4.03(a),
4.03(b), 4.03(c), 4.03(d), 4.03(e), 4.03(f) and 4.05 hereof (the "Regulatory
Allocations") are intended to comply with certain requirements of the Treasury
Regulations. It is the intent of the Partners that, to the extent possible, all
Regulatory Allocations shall be offset either with other Regulatory Allocations
or with special allocations of other items of Partnership income, gain, loss or
deduction pursuant to this Section 4.04. Therefore, notwithstanding any other
provision of this Article 4 (other than the Regulatory Allocations), the General
Partner shall make such offsetting special allocations of Partnership income,
gain, loss or deduction in whatever manner it determines appropriate so that,
after such offsetting allocations are made, each Partner's Capital Account
balance is, to the extent possible, equal to the Capital Account balance such
Partner would have had if the Regulatory Allocations were not part of this
Agreement and all Partnership items were allocated pursuant to Sections 4.01,
4.02 and 4.03(h) hereof.

      4.05 Loss Limitation. Losses allocated pursuant to Section 4.02 hereof
shall not exceed the maximum amount of Losses that can be allocated without
causing any Partner to have an Adjusted Capital Account Deficit at the end of
any Allocation Year. In the event some but not all of the Partners would have
Adjusted Capital Account Deficits as a consequence of an allocation of Losses
pursuant to Section 4.02 hereof, the limitation set forth in this Section 4.05
shall be applied on a Partner-by-Partner basis and Losses not allocable to any
Partner as a result of such limitation


                                       20
<PAGE>   29
shall be allocated to the other Partners in accordance with the positive
balances in such Partners' Capital Accounts so as to allocate the maximum
permissible Losses to each Partner under Section 1.704-1(b)(2)(ii)(d) of the
Treasury Regulations.

      4.06 Other Allocation Rules.

            (a) For purposes of determining the Profits, Losses or any other
      items allocable to any period, Profits, Losses and any such other items
      shall be determined on a daily, monthly or other basis, as determined by
      the General Partner using any permissible method under Code Section 706
      and the Treasury Regulations thereunder.

            (b) The Partners are aware of the income tax consequences of the
      allocations made by this Article 4 and hereby agree to be bound by the
      provisions of this Article 4 in reporting their shares of Partnership
      income and loss for income tax purposes.

            (c) Solely for purposes of determining a Partner's proportionate
      share of the "excess nonrecourse liabilities" of the Partnership within
      the meaning of the Treasury Regulations Section 1.752-3(a)(3), the
      Partners' interests in Partnership profits are in proportion to their
      Units.

            To the extent permitted by Section 1.704-2(h)(3) of the Treasury
      Regulations, the General Partner shall endeavor to treat distributions of
      Net Cash Flow as having been made from the proceeds of a Nonrecourse
      Liability or a Partner Nonrecourse Debt only to the extent that such
      distributions would cause or increase an Adjusted Capital Account Deficit
      for any Partner.

      4.07 Contributed Property; Tax Allocations.

            (a) Code Section 704(c). In accordance with Code Section 704(c) and
      the Treasury Regulations thereunder, income, gain, loss and deduction with
      respect to any Property contributed to the capital of the Partnership
      shall, solely for tax purposes, be allocated among the Partners so as to
      take account of any variation between the adjusted basis of such Property
      to the Partnership for federal income tax purposes and its initial Gross
      Asset Value (computed in accordance with the definition of Gross Asset
      Value) using an acceptable allocation method pursuant to the Treasury
      Regulations under Section 704(c) as selected by the General Partner.

            (b) In the event the Gross Asset Value of any Partnership asset is
      adjusted pursuant to subparagraph (ii) of the definition of Gross Asset
      Value, subsequent allocations of income, gain, loss and deduction with
      respect to such asset shall take account of any variation between the
      adjusted basis of such asset for federal income tax purposes and its Gross
      Asset Value in the same manner as under Code Section 704(c) and the
      Regulations thereunder.


                                       21
<PAGE>   30
            (c) Any elections or other decisions relating to such allocations
      shall be made by the General Partner in any manner that reasonably
      reflects the purpose and intention of this Agreement. Allocations pursuant
      to this Section 4.07 are solely for purposes of federal, state and local
      taxes and shall not affect, or in any way be taken into account in
      computing, any Partner's Capital Account or share of Profits, Losses,
      other items or distributions pursuant to any provision of this Agreement.

      4.08 Distributions. The Partnership shall distribute cash to the Partners,
as determined in the sole and exclusive discretion of the General Partner. No
fees, salary, loans or other amounts paid to a Partner in connection with an
arm's-length transaction shall be considered a distribution, including, without
limitation, payments made pursuant to the Project Agreements. Distributions of
cash or property in respect of an Interest shall be made only to a Partner who,
according to the books and records of the Partnership, is the holder of such
Interest in respect of which such distribution is made on the date of such
distribution. The date for any distributions shall be determined by the General
Partner in its sole discretion. Except as provided in Section 7.03 hereof, all
distributions of cash or property (other than distributions in connection with
the dissolution and liquidation of the Partnership) shall be allocated among the
Partners in proportion to their Interests. Distributions among each class of
Unit shall be proportional by Unit, except as provided in Section 7.03 hereof.
Distributions in connection with the termination and liquidation of the
Partnership shall be allocated among the Partners as provided in Section 10.04
hereof.

                                    ARTICLE 5

                    RIGHTS AND DUTIES OF THE GENERAL PARTNER

      5.01 Management. The Partnership shall be managed by the General Partner
who shall have, subject to any restrictions imposed by applicable law or
expressly imposed by this Agreement, full, complete and exclusive authority to
(i) manage and control the business, affairs and properties of the Partnership,
(ii) make all decisions regarding those matters and (iii) perform any and all
other acts or activities customary or incident to the management of the
Partnership's business. In addition to the powers now or hereafter granted the
general partners of a limited partnership under the Act or that are granted the
General Partner under any provision of this Agreement, but subject to the
limitations described in Section 5.03 hereof and elsewhere in this Agreement,
the General Partner shall have the power, for and on behalf and in the name of
the Partnership, to carry out and implement the purpose of the Partnership set
forth in Section 2.05 hereof and to do all things necessary or desirable or
expedient in connection therewith or incidental thereto and to manage, conduct
and supervise the day-to-day business affairs of the Partnership.

      5.02 Reliance by Public.

            (a) In order to expedite the handling of the Partnership's business
      and affairs, it is understood and agreed that any action taken or document
      delivered by the General Partner while acting in the name and on behalf of
      the Partnership shall be deemed to be the action of the Partnership as to
      any third parties (including all Limited Partners or their assignees as


                                       22
<PAGE>   31
      third parties for such purpose). Any Person dealing with the Partnership
      or the General Partner shall be entitled to rely upon a certificate of the
      General Partner as to:

                  (i) the identity of the Partners;

                  (ii) the existence or nonexistence of any fact or facts that
            constitute conditions precedent to acts by the party delivering or
            receiving such certificate or which are in any other manner related
            to the affairs of the Partnership;

                  (iii) the Persons who are authorized to execute and deliver
            any instrument or document of the Partnership;

                  (iv) any act or failure to act by the Partnership; or

                  (v) any other matter whatsoever involving the Partnership or
            any Partner.

            (b) Notwithstanding any other provision of this Agreement to the
      contrary, no Person shall be required to look to the application of
      proceeds hereunder or to verify any representation by the General Partner.
      Any such Person shall be entitled to rely exclusively on the
      representations of the General Partner as to its authority to enter into
      such financing or sale arrangements and shall be entitled to deal with the
      General Partner as if it were the sole party in interest therein, both
      legally and beneficially.

      5.03 Restrictions on Authority of General Partner. Notwithstanding any
other provision of this Agreement to the contrary, the General Partner shall not
have the power or authority to, and shall not:

            (a) cause the Partnership to make any loans to the General Partner
      or any of its Affiliates unless approved by Unanimous Consent;

            (b) receive or cause any Affiliate to receive any brokerage
      commission or similar fee in connection with the sale or reinvestment of
      the proceeds of sale, exchange or refinancing of any Partnership Property,
      except as disclosed to the Partners and approved by Unanimous Consent;

            (c) accept any rebates in connection with Partnership operations or
      expenditures other than those received for the account of the Partnership
      or as are approved by Unanimous Consent;

            (d) sell, transfer or assign (other than collateral assignments and
      transfers which shall be governed by Section 3.05 hereof) all or any
      material portion of the assets of the Partnership unless approved by
      Unanimous Consent; or


                                       23
<PAGE>   32
            (e) approve any System Modification without the approval of the
      Required Interest plus the approval of the General Partner.

      5.04 Other Operations. The General Partner shall devote all of its time to
the Partnership to carry on the Partnership's business.

      5.05 Disposition of All or Substantially All of Partnership Property. The
General Partner shall be empowered to Dispose of all (being 80% or more of fair
market value) of the Partnership's Property (including its goodwill) to any of
its Affiliates or any other Person, and to receive for the Partnership
consideration consisting of cash, securities, other property, assumption of
Partnership debts, any other form of consideration or any combination thereof,
as it deems to be in the best interests of the Limited Partners; provided,
however, that no such Disposition shall be consummated unless prior Unanimous
Consent is received. The consent of Limited Partners shall not be required for
the General Partner to encumber or assign, as security for the payment of
Partnership indebtedness or obligations, all or substantially all Partnership
Property.

      5.06 Contracts with the Partners or their Affiliates. The General Partner,
in its sole and exclusive discretion, may cause the Partnership to enter into
other contracts and arrangements with the Partners and its Affiliates for the
rendering of services and the sale and lease of supplies and equipment;
provided, however, that the compensation, price, or rental and other terms to
the Partnership must be no less favorable to the Partnership, taken as a whole,
than that generally available from unrelated third parties in the area who are
engaged in the business of rendering comparable services or selling or leasing
comparable equipment and supplies which could reasonably be made available to
the Partnership. The Limited Partners, by their execution of this Agreement,
acknowledge and consent to the Partnership entering into the Project Agreements.
Employee expenses for all non-Columbia employees of the Partners or their
Affiliates that are approved by the General Partner shall be recoverable at the
rate of $400.00 per day plus all reasonable travel and travel related expenses
of such employees that are for the benefit of the Partnership provided that they
are submitted within forty-five (45) days of the end of the month in which the
expenses were incurred.

      5.07 Liabilities and Indemnification of the General Partner.

            (a) THE GENERAL PARTNER AND ITS AFFILIATES SHALL NOT BE LIABLE TO
      THE PARTNERSHIP OR THE PARTNERS FOR ANY LOSS OR DAMAGE INCURRED BY THE
      PARTNERSHIP OR ANY PARTNER BY REASON OF ANY ACT OR OMISSION (WHETHER
      NEGLIGENT OR NOT) PERFORMED OR OMITTED BY THE GENERAL PARTNER OR ITS
      AFFILIATES IN GOOD FAITH AND IN A MANNER REASONABLY BELIEVED BY THE
      GENERAL PARTNER TO BE WITHIN THE SCOPE OF THE AUTHORITY GRANTED TO THE
      GENERAL PARTNER BY THIS AGREEMENT. THE PARTNERSHIP SHALL INDEMNIFY AND
      SAVE HARMLESS THE GENERAL PARTNER AND ITS AFFILIATES TO THE FULLEST EXTENT
      NOW OR HEREAFTER PERMITTED BY THE ACT.


                                       24
<PAGE>   33
            (b) Legal expenses and other costs incurred by the General Partner
      and its Affiliates shall be reimbursed on a monthly basis by the
      Partnership in advance of the final disposition of claims for which the
      General Partner or its Affiliates may be entitled to be indemnified or
      held harmless, provided that each Person to whom reimbursement is to be
      made undertakes to repay funds so advanced if it is later determined by
      final, non-appealable judgment of a court of competent jurisdiction that
      such Person is not entitled to be indemnified or held harmless by the
      Partnership. The right of the General Partner and its Affiliates to be
      indemnified and held harmless under this Agreement shall continue after
      the General Partner ceases to be a Partner. All rights of the General
      Partner and its Affiliates under this Section 5.07 shall inure to their
      respective successors and assigns.

      5.08 Title to Partnership Properties. Title to all Partnership Property
shall be taken, held and recorded in the name of the Partnership.

      5.09 Transfer of Interest of General Partner.

            (a) The General Partner may assign its right or delegate its
      responsibility to manage the affairs of the Partnership as the General
      Partner deems reasonable and necessary, in its sole discretion. The
      General Partner may transfer its share of the profits and distributions
      from the Partnership without receiving the consent or approval of any
      Partner. The Limited Partners hereby consent and agree to the delegation
      of responsibilities of the General Partner pursuant to the Project
      Agreements as the General Partner deems reasonable and necessary in the
      sole discretion of the General Partner.

            (b) The General Partner may assign all or any portion of its
      Interest to any General Partner admitted to the Partnership pursuant to
      Article 7 hereof.

            (c) Notwithstanding the foregoing, nothing in this Agreement shall
      be deemed to prevent (and all Limited Partners hereby expressly consent
      to) the Disposition by the General Partner of its rights and Interest, and
      the delegation of all its obligations to the Partnership and the Partners
      to one or more Persons that have, as the result of a merger,
      consolidation, asset purchase, corporate reorganization or other
      transaction, acquired all or substantially all of the assets of the
      General Partner and have assumed the obligations of the General Partner
      hereunder.

      5.10 Compensation.

            (a) The General Partner shall be reimbursed by the Partnership for
      all pre-approved and budgeted expenses incurred for the direct benefit of
      the Partnership.

            (b) Any amounts due to the General Partner by the Partnership
      pursuant to subsection (a) of this Section which are not paid to the
      General Partner within thirty (30) days after such payment was due as the
      result of the Partnership having insufficient funds to


                                       25
<PAGE>   34
      pay such costs and meet other anticipated operating expenses shall,
      after such thirty (30) day period, bear interest until paid at the Base
      Interest Rate.

                                    ARTICLE 6

                   RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS

      6.01 Limitation of Liability. No Limited Partner shall be liable to the
Partnership for the debts, liabilities, contracts or any other obligations of
the Partnership, except to the extent of its Interest in the Partnership, and as
provided herein.

      6.02 Management of Business. No Limited Partner, in its capacity as a
Limited Partner, shall take part in the operation, management, or control of the
Partnership business, transact any business in the Partnership's name, or have
the power to sign documents for or otherwise bind the Partnership.

      6.03 Conflicts of Interest.

            (a) The Limited Partners and their Affiliates agree not to
      participate in the development of or invest in, directly or indirectly as
      an equity participant, any other greenfield project or venture into the
      U.S. Northeast which, if developed, would offer natural gas transportation
      services in competition with the Millennium Pipeline System until December
      31, 1998, unless a Partner discloses such interest in a potentially
      competing project and receives written consent to participate from all of
      the other Limited Partners. The Limited Partners and their Affiliates
      shall be free to pursue any complementary or non-competing ventures
      without the participation of any other Partner. The Limited Partners
      hereby agree that Columbia's service on its existing transmission system
      and Columbia's market expansion project authorized pursuant to FERC Docket
      No. CP96-213 will not be deemed as a violation of its covenant not to
      compete. The Limited Partners further acknowledge that Westcoast (or an
      Affiliate) is involved in the Maritimes and Northeast Pipeline Project,
      MCN (or an Affiliate) is involved in the Portland Natural Gas Transmission
      Project, and TransCanada (or an Affiliate) is involved in the
      TransMaritime Gas Transmission Project, Iroquois Gas Transmission and the
      Portland Natural Gas Transmission Project, as well as TransCanada
      PipeLines Limited "Canadian Mainline", and the Partners agree that
      participation or ownership in any of the aforementioned projects or
      pipelines, or any contemplated or future expansions thereof, will not be a
      violation of the covenant not to compete.

            (b) From and after December 31, 1998 (or such other date as may be
      determined by Unanimous Consent), each Limited Partner and its Affiliates
      at any time and from time to time may engage in and possess interests in
      other business ventures of any and every type and description,
      independently or with others, including ones in competition with the
      Partnership, with no obligation to offer to the Company, any other Limited
      Partner or any of their Affiliates the right to participate therein.
      Neither the Partnership nor any of the other


                                       26
<PAGE>   35
      Partners shall have any rights by virtue of this Agreement in and to such
      independent business ventures or to the income or profits derived
      therefrom.

            (c) The Partnership shall not engage in any Affiliate Transaction
      unless (i) the terms of each Affiliate Transaction are no less favorable
      than those the Partnership could obtain from unrelated third parties and
      (ii) each Affiliate Transaction involving in excess of US$10,000 in the
      aggregate is approved by the General Partner.

      6.04 Restrictions on Disposition of Limited Partner's Interest.

            (a) Except as specifically provided in this Section 6.04, a
      Disposition of a Limited Partner's Interest in the Partnership may not be
      affected without the consent of a Required Interest and approval by the
      General Partner. Any attempted Disposition by a Limited Partner of its
      Interest or other right in the Partnership other than in accordance with
      this Section 6.04 shall be, and it hereby is, declared null and void ab
      initio. A Change in Control of a Limited Partner or a Limited Partner
      Owner shall be considered a Disposition of a Limited Partner's Interest.

            (b) Notwithstanding the provisions of Section 6.04(a) hereof, the
      Interest of any Limited Partner may be Disposed of without the consent of
      the Required Interest and approval of the General Partner if (i) the
      Disposition is to an Affiliate and (ii) such Disposition does not violate
      any other provision of this Agreement.

            (c) Subject to the provisions of Sections 6.04(d), (e), (f) and (g)
      hereof, (i) a Person to whom a Limited Partner's Interest in the
      Partnership is transferred has the right to be admitted to the Partnership
      as a substitute limited partner ("Substitute Limited Partner"), entitled
      to all the rights and benefits under this Agreement of the Limited Partner
      effecting such Disposition in proportion to the Interest so transferred to
      such Person if (A) the General Partner and the Limited Partner making such
      transfer grant the transferee the right to be so admitted, and (B) such
      transfer is consented to in accordance with Section 6.04(a) hereof; and
      (ii) an Affiliate under the circumstances described in Section 6.04(b)
      hereof has the right to be admitted to the Partnership as a Limited
      Partner with the Interest so transferred to the Affiliate.

            (d) The Partnership may not recognize, for any purpose, any
      purported Disposition of all or part of a Limited Partner's Interest
      unless and until the other applicable provisions of this Section 6.04 have
      been satisfied, and the General Partner has received, on behalf of the
      Partnership, a document (i) executed by both the Limited Partner effecting
      the Disposition (or, if the Disposition is on account of the liquidation
      of the transferor, its representative) and the Person to which the Limited
      Partner's Interest or part thereof is Disposed, (ii) including the notice
      address of any Person to be admitted to the Partnership as a Substitute
      Limited Partner and its agreement in writing to be bound by this Agreement
      and all amendments hereto in respect of the Limited Partner's Interest or
      part thereof being obtained, (iii) setting forth the Interests after the
      Disposition of the Limited Partner effecting


                                       27
<PAGE>   36
      the Disposition and the Person to which the Limited Partner's Interest or
      part thereof is Disposed (which together must total the Interest of the
      Limited Partner effecting the Disposition before the Disposition), (iv)
      containing a representation and warranty that the Disposition was made in
      accordance with all applicable laws and regulations (including securities
      laws) and, if the Person to which the Limited Partner's Interest or part
      thereof is Disposed is to be admitted to the Partnership, its
      representation and warranty that the representations and warranties in
      Section 9.01 hereof are true and correct with respect to that Person, and
      (v) the Limited Partner effecting a Disposition executes a waiver of
      liability in favor of the other Limited Partners and the General Partner
      in form and substance acceptable to the General Partner. Each Disposition
      and, if applicable, admission complying with the provisions of this
      Section 6.04(d) shall be effective as of the first day of the calendar
      month immediately succeeding the month in which the General Partner
      receives the notification of Disposition and the other requirements of
      this Section 6.04 have been met.

            (e) For the right of a Limited Partner to Dispose of a Limited
      Partner's Interest or any part thereof or of any Person to be admitted to
      the Partnership in connection therewith to exist or to be exercised,
      either (A) the Limited Partner's Interest or part thereof subject to the
      Disposition or admission must be registered under the Securities Act of
      1933, as amended, and any applicable state securities laws or (B) the
      General Partner on behalf of the Partnership must receive a favorable
      opinion by the Partnership's legal counsel or by other legal counsel
      acceptable to the General Partner to the effect that the Disposition or
      admission is exempt from registration under those laws.

            (f) The Limited Partner effecting a Disposition, and any Person
      admitted to the Partnership in connection therewith, shall pay, or
      reimburse the Partnership for, all costs incurred by the Partnership in
      connection with the Disposition or admission (including, without
      limitation, the legal fees incurred in connection with the legal opinions
      referred to in Section 6.04(e) hereof, on or before the tenth (10th) day
      after the receipt by that Person of the Partnership's invoice for the
      amount due. If payment is not made by the date due, the Person owing that
      amount shall pay interest on the unpaid amount from the date due until
      paid, at a rate per annum equal to the Base Interest Rate.

            (g) Each Limited Partner agrees that he will, upon request of the
      General Partner, execute such certificates or other documents and perform
      such acts as the General Partner deems appropriate after a Disposition of
      Interest by that Limited Partner to preserve the limited liability status
      of the Partnership under the laws of the jurisdictions in which the
      Partnership is doing business or to otherwise comply with applicable laws.


                                       28
<PAGE>   37
      6.05 Right of First Refusal.

            (a) Subject to Section 6.10 hereof, at any time following the
      Effective Date, any Limited Partner desiring to Dispose of all or any part
      of its Interest to any Person other than an Affiliate (the "Disposing
      Partner") shall first have received a written offer from the prospective
      purchaser, and, as a condition precedent to its right to Dispose of the
      Interest, the Disposing Partner shall notify the General Partner and the
      other Limited Partners of its intention to Dispose of all or a specified
      part of its Interest. The notice shall be in writing setting forth in
      detail the name of the prospective purchaser and the terms and conditions
      of the proposed Disposition (the "Sale Notice") and shall offer to Dispose
      of such Partner's Interest at the same price and on the same terms and
      conditions ("Third Party Terms"). The Partners and their designated
      Affiliates (each an "Offeree Partner"), shall have the right to purchase
      the Interest on the Third Party Terms within thirty (30) days after the
      delivery of the Sale Notice to the Partnership (the "Notice Period"). In
      the event the Offeree Partners do not elect to purchase the Interest
      offered by the Disposing Partner on the Third Party Terms, then the
      Disposing Partner shall be free to Dispose of the Interest in accordance
      with the terms set out in the Sale Notice, subject to the other terms of
      this Agreement, including Section 6.04 hereof, which shall apply to any
      transferee. If such Disposition does not occur within thirty (30) days
      after termination of the Notice Period, the Disposing Partner shall be
      required to again comply with all the provisions of this Section 6.05.

            (b) If any Third Party Terms contemplate that all or any part of the
      purchase price for the proposed Disposition of an Interest will be paid in
      any form other than cash, the fair market value of the offer shall be an
      amount (in U.S. dollars) determined as follows: (i) cash payable at
      closing shall be valued at the amount thereof in U.S. dollars, (ii) a
      security trading on a public market and for which published trading prices
      are readily available shall be valued at its closing sales price (or if a
      sales price is not available at the average of its closing bid and asked
      prices) on the last Business Day preceding the date of the offer with
      respect to such offer, and (iii) a security not described in clause (ii)
      or other property, including cash payable in one or more installments,
      shall be valued at its fair market value on the last Business Day
      preceding the date of the offer, as determined by a majority vote of the
      Partners who are not Disposing Partners, which determination shall be
      binding upon the Partners for purposes of determining the fair market
      value of the offer. If the non-Disposing Partners, by majority vote, are
      unable or unwilling to agree on the fair market value of the offer, the
      General Partner shall select an independent appraiser to determine the
      fair market value of the offer, which determination shall be binding upon
      the Partners for purposes of determining the fair market value of the
      offer.

      6.06 Assignee's Rights. An assignee of all or any part of a Limited
Partner's Interest shall be entitled to receive distributions of cash or other
property from the Partnership attributable to such Interest after the effective
date of the Disposition. The effective date of an assignment of an Interest
under the provisions of this Article 6 for the purposes of Partnership
accounting shall be the first date of the calendar month following the date on
which all conditions precedent to such assignment provided for in this Agreement
are, in the opinion of the General Partner, fulfilled. An assignee of


                                       29
<PAGE>   38
all or any part of a Limited Partner's Interest who does not become a Substitute
Limited Partner in accordance with this Article 6 shall have no right to require
any information or account of the Partnership's transactions or to inspect the
Partnership's books.

      6.07 No Liability of General Partner for Distributions. Notwithstanding
anything herein to the contrary, both the Partnership and the General Partner
shall be entitled to treat the assignor of an Interest as the absolute owner
thereof in all respects, and shall incur no liability for distributions of cash
made to him, until such time as all conditions and requirements of this Article
6 have been, in the opinion of the General Partner, met.

      6.08 Indemnification. Each Limited Partner shall indemnify and hold
harmless the Partnership, the General Partner and every other Limited Partner
who was or is a party or is threatened to be made a party to any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative, by reason of or arising from (a) any actual or
alleged misrepresentation or misstatement of facts or omission to state facts
made by such Limited Partner in connection with any Disposition of all or any
part of an Interest, (b) the consent to or refusal of the General Partner to
consent to the Disposition of all or any part of such Limited Partner's Interest
to the fullest extent provided by the Act or (c) the admission of or refusal to
admit an assignee or transferee of all or any part of such Limited Partner's
Interest as a Substitute Limited Partner, from and against expenses actually and
reasonably incurred by it in connection with such action, suit or proceeding for
which the Partnership or such Partner has not otherwise been reimbursed
(including attorneys' fees, judgments, fines and amounts paid in settlement).

      6.09 No Dissolution Caused. The bankruptcy or withdrawal pursuant to this
Agreement of a Limited Partner shall not cause a dissolution of the Partnership.
The admission of any additional or substitute General or Limited Partner shall
not cause a dissolution of the Partnership.

      6.10 PUHCA. Notwithstanding anything to the contrary contained in this
Agreement, any Disposition of a Limited Partner Interest or the acquisition of a
Limited Partner Interest by a Partner permitted in this Agreement shall not be
so permitted, without Unanimous Consent, if the effect of such Disposition or
acquisition would cause the Company or the Partnership to become (i) a
"subsidiary company" of a "holding company;" (ii) an "affiliate" of a "holding
company;" or (iii) an "affiliate" of a "subsidiary company" of a "holding
company" (as such terms are defined in PUHCA) that are not exempt from the
obligations, duties and liabilities imposed by PUHCA (collectively, a "PUHCA
Company").

      6.11 Remedies. The Partnership and/or any Partner shall have the right to
enforce its rights under this Article 6 by specific performance.


                                       30
<PAGE>   39
                                    ARTICLE 7

             WITHDRAWAL OF THE GENERAL PARTNER AND LIMITED PARTNERS;
                    ADMISSION OF ADDITIONAL GENERAL PARTNERS

      7.01 Withdrawal of the General Partner. The General Partner does not have
the right to withdraw from the Partnership as the General Partner without
Unanimous Consent. The General Partner agrees that it will not voluntarily
withdraw from the Partnership as a general partner within the meaning of Section
17-602 of the Act, and any such withdrawal shall be a breach of this Agreement.

      7.02 Admission of Additional General Partner. The General Partner may
cause the Partnership to admit as an additional General Partner any Affiliate of
any of the Partners. The Limited Partners hereby consent in advance to such an
admission of an additional General Partner pursuant to this Section 7.02;
provided, however, that such admission shall not in any manner reduce the
Interests of the Limited Partners. Unless otherwise agreed by the General
Partner and the Person to be admitted as an additional General Partner, the
additional General Partner so admitted shall have the same rights and
responsibilities as the General Partner under this Agreement.

      7.03 Withdrawal of a Limited Partner and Effect of Withdrawal.

            (a) Prior to the Commitment Voting Date and subject to subsections
      7.03(b), (c) and (d) hereof, any Limited Partner may elect to withdraw as
      a Partner from the Partnership by delivering notice of such Limited
      Partner's intention to withdraw to the General Partner and the other
      Limited Partners on or prior to the Commitment Voting Date (the
      "Withdrawal Notice"). The Withdrawal Notice shall be invalid if the
      Limited Partner or the Limited Partner's Affiliate that is a Member of the
      General Partner does not also deliver a "Withdrawal Notice" pursuant to
      the Regulations of Millennium Pipeline Management Company, L.L.C. Any
      Limited Partner sending a valid Withdrawal Notice shall become a
      "Withdrawing Limited Partner." From and after the Commitment Voting Date,
      a Limited Partner shall have no right or power to withdraw as a Partner
      from the Partnership.

            (b) To the extent the withdrawal of any Partner would have the
      effect of causing the Partnership to become a PUHCA Company, the
      Withdrawal Notice shall not immediately affect the withdrawal of the
      Limited Partner and withdrawal shall not occur until the earlier of (i)
      the receipt of Unanimous Consent and (ii) two hundred seventy (270) days
      from the date of the Withdrawal Notice (in such circumstances, the date on
      which the earlier of the events described in clauses (i) and (ii) occurs
      being hereinafter referred to as the "Withdrawal Effective Date");
      provided, however, that the non-withdrawing Limited Partners shall
      endeavor to accommodate the Withdrawing Limited Partner's withdrawal to
      become effective prior to the expiration of the time period described in
      subsection 7.03(b)(ii). If the withdrawal of the Withdrawing Limited
      Partner would not have the effect of causing the Partnership to become a
      PUHCA Company and the Withdrawing Limited Partner delivers to the General
      Partner a legal opinion to such effect, the Withdrawal Effective Date
      shall be


                                       31
<PAGE>   40
      the tenth (10th) day following the Withdrawing Limited Partner's delivery
      of its Withdrawal Notice.

            (c) Upon delivery of the Withdrawal Notice, the Withdrawing Limited
      Partner shall not (i) be entitled to any distributions from the
      Partnership and (ii) have any obligation to make additional Capital
      Contributions to the Company except Capital Contributions relating to the
      expenditure of funds by the Partnership which was approved by the Partners
      prior to the delivery of the Withdrawal Notice and Scheduled Capital
      Contributions which are scheduled to be made prior to the delivery of the
      Withdrawal Notice. A Withdrawing Partner shall be entitled to a return of
      the cash equivalent of the value of its Capital Contributions; provided,
      that such return of Capital Contributions shall not begin until after the
      date on which the Millennium Pipeline System is fully operational and
      in-service (the "In-Service Date"). Capital Contributions shall be
      returned to a Withdrawing Partner if and when distributions are made to
      the non-Withdrawing Partners as provided in this Agreement and shall be
      paid to the Withdrawing Partner in one or more installments in amounts
      equal to the sum that the Withdrawing Partner would have received if it
      had not become a Withdrawing Partner (based upon the Withdrawing Partner's
      Interest at the time of becoming a Withdrawing Partner) until the
      Withdrawing Partner receives a sum equal to its aggregate Capital
      Contributions. Interest shall accrue on the undistributed sums to be
      distributed to a Withdrawing Partner at the General Interest Rate from a
      date which commences three (3) months from the In-Service Date.

            (d) Except as provided in Section 7.03(b), withdrawal by a Limited
      Partner may not occur without Unanimous Consent if the effect of the
      withdrawal would be to cause the Partnership, the General Partner or both
      to become a PUHCA Company.

            (e) A Withdrawing Limited Partner shall be treated as an Abstaining
      Partner for the purpose of any matter to be voted on by the Partners.

            (f)Notwithstanding any other provisions of this Section 7.03, a
      Withdrawing Limited Partner shall be entitled to receive a copy of each
      financial report prepared for and distributed to the non-withdrawing
      Limited Partners as required by Section 8.04 hereof until such time as the
      Withdrawing Limited Partner's Capital Contributions have been returned to
      such Withdrawing Member.

            (g) The non-Withdrawing Limited Partners shall have the right but
      not the obligation for a period of sixty (60) days from the date of the
      Withdrawal Notice to purchase the Interest of a Withdrawing Limited
      Partner for an amount equal to the aggregate Capital Contributions of the
      Withdrawing Limited Partner and such Interest shall be sold free and clear
      of all claims, liens and encumbrances. If more than one non-Withdrawing
      Limited Partner elects to purchase the Interest of the Withdrawing Limited
      Partner, such Limited Partners shall be entitled to purchase such Interest
      on a pro rata basis or in such other manner as they mutually agree.


                                       32
<PAGE>   41
      7.04 Indemnification of Withdrawing Limited Partner. If a Withdrawing
Limited Partner is made a party to or is threatened to be made a party to or is
involved in any threatened, pending or completed action, suit or proceeding,
whether civil, criminal, administrative, arbitrative or investigative
(hereinafter an "Action"), or any appeal of such an Action during the period
between the date of the Withdrawal Notice and the Withdrawal Effective Date (the
"Withdrawal Period") or if any Action is brought (whether during or after the
Withdrawal Period) in which the Withdrawing Limited Partner is made a Party
based upon events transpiring during the Withdrawal Period, such Withdrawing
Limited Partner shall be indemnified by the Partnership. The rights granted
pursuant to this Section 7.04 shall be deemed contract rights, and no amendment,
modification or repeal of this Section 7.04 after a Withdrawal Notice is
delivered shall have the effect of limiting or denying any such rights granted
hereunder to a Withdrawing Limited Partner.

                                    ARTICLE 8

                         FISCAL YEAR; BOOKS OF ACCOUNT;
                           BANK ACCOUNTS; AND REPORTS

      8.01 Books and Records.

            (a) The General Partner, at the expense of the Partnership, shall
      maintain for the Partnership adequate books and records of account which
      shall be maintained, except as otherwise required by law, on the accrual
      basis in accordance with the terms of this Agreement and Required
      Accounting Practices, consistently applied. Notwithstanding the foregoing,
      the Capital Accounts for each Partner shall also be maintained in
      accordance with Article 3 hereof. The Partnership shall adopt the calendar
      year as its fiscal year.

            (b) The Limited Partners and their agents may, at their own cost and
      expense, examine, audit and obtain copies of the books, records and
      accounts of the Partnership, including federal, state and local income tax
      returns for each year as and when they become available, inspect its
      Properties, or otherwise make reasonable inquiry as to Partnership
      affairs. Any such inspections shall be conducted during the normal
      business hours of the General Partner.

      8.02 Bank Accounts. All funds of the Partnership shall be deposited in its
name in such bank account or accounts as may be designated by the General
Partner. The General Partner and any Persons authorized in writing by it to do
so shall be authorized to draw checks on the bank accounts of the Partnership.
Each bank in which a Partnership account is maintained shall be relieved of any
responsibility to inquire into the authority of the General Partner to deal with
such funds.

      8.03 Tax Elections.

            (a) The General Partner shall make the following elections for the
      Partnership in the first and subsequent tax years:


                                       33
<PAGE>   42
                  (i) To elect December 31st as the end of the fiscal year of
            the Partnership; provided, however, that the fiscal year of the
            Partnership may be changed to any twelve (12) month period approved
            by the General Partner;

                  (ii) To elect to have the General Partner be the "tax matters
            partner" pursuant to Section 6231(a)(7)(A) of the Code;

                  (iii) To deduct expenses incurred in organizing the
            Partnership ratably over a sixty (60) month period as provided in
            Code Section 709;

                  (iv) If a distribution of Partnership property as described in
            Section 734 of the Code occurs or if a transfer of an Interest as
            described in Section 743 of the Code occurs, on written request of
            any Partner, to elect, pursuant to Section 754 of the Code, to
            adjust the basis of Partnership properties; and

                  (v) Subject to the other provisions of this Section 8.03, all
            other elections required or permitted to be made by the Partnership
            under the Code shall be made by the General Partner in its sole
            discretion.

            (b) No election shall be made by the Partnership or any Partner for
      the Partnership to be excluded from the application of any of the
      provisions of Subchapter K, Chapter 1 of Subtitle A of the Code, or from
      any similar provisions of any state tax laws.

            (c) The Partnership is intended to be classified as a partnership
      for federal and state income tax purposes. No election shall be made by
      the Partnership or any Partner to classify the Partnership as an
      association pursuant to regulations issued under Code Section 7701 or any
      similar provision of any state tax law.

      8.04 Annual and Quarterly Reports. The General Partner shall furnish to
the Limited Partners (a) within ninety (90) days after the Partnership's fiscal
year financial statements of the Partnership as at and for the period ending
December 31 of the preceding year, including a balance sheet, a statement of
income, a statement of changes in Partners' equity, and a statement of cash
flows and accompanying independent auditor's report, if any, all of which shall
be prepared in accordance with Required Accounting Practices, consistently
applied; and (b) within forty-five (45) days after the end of each calendar
quarter, a quarterly report as at and for such calendar quarter including a
balance sheet, a statement of income, a statement of Partners' equity, and a
statement of cash flows, all of which shall be prepared in accordance with
Required Accounting Practices, consistently applied. The General Partner shall
use its best efforts to furnish such other reports as reasonably requested by
the Limited Partners.

      8.05 Tax Reporting Information. The General Partner shall furnish the
Limited Partners a report within one hundred twenty (120) days after the close
of the Partnership's fiscal year containing all tax reporting information
reasonably necessary for federal income tax purposes.


                                       34
<PAGE>   43
      8.06 Reporting Expenses. The General Partner shall be reimbursed for all
expenses incurred by the General Partner in preparing (or causing to be
prepared) reports to Limited Partners.

                                    ARTICLE 9

               REPRESENTATIONS AND WARRANTIES OF LIMITED PARTNERS

      9.01 Representations and Warranties. Each Limited Partner further
represents and warrants that the following statements are true:

            (a) Such Limited Partner is a corporation duly organized or a
      partnership, limited liability company or other entity duly formed,
      validly existing and in good standing under the laws of the jurisdiction
      of its incorporation or formation and has the corporate, partnership or
      company power and authority to own its property and carry on its business
      as owned and carried on at the date hereof and as contemplated hereby.
      Such Limited Partner is duly licensed or qualified to do business and is
      in good standing in each of the jurisdictions in which the failure to be
      so licensed or qualified would have a material adverse effect on its
      financial condition or its ability to perform its obligations hereunder.
      Such Limited Partner has the corporate, partnership or company power and
      authority to execute and deliver this Agreement and to perform its
      obligations hereunder and the execution, delivery and performance of this
      Agreement has been duly authorized by all necessary corporate, partnership
      or company action. This Agreement constitutes the legal, valid and binding
      obligation of such Limited Partner.

            (b) Neither the execution, delivery and performance of this
      Agreement nor the consummation by such Limited Partner of the transactions
      contemplated hereby will (i) conflict with, violate or result in a breach
      of any of the terms, conditions or provisions of any law, regulation,
      order, writ, injunction, decree, determination or award of any court,
      governmental department, board, agency or instrumentality, domestic or
      foreign, or any arbitrator, applicable to such Limited Partner, (ii)
      conflict with, violate, result in a breach of or constitute a default
      under any of the terms, conditions or provisions of the articles or
      certificate of incorporation, bylaws, partnership agreement or operating
      agreement of such Limited Partner or of any material agreement or
      instrument to which such Limited Partner is a party or by which such
      Limited Partner is or may be bound or to which any of its material
      properties or assets is subject, (iii) conflict with, violate, result in a
      breach of, constitute a default under (whether with notice or lapse of
      time or both), accelerate or permit the acceleration of the performance
      required by, give to others any material interests or rights to require
      any consent, authorization or approval under any indenture, mortgage,
      lease agreement or instrument to which such Limited Partner is a party or
      by which such Limited Partner is or may be bound or (iv) result in the
      creation or imposition of any lien upon any of the material properties or
      assets of such Limited Partner.

            (c) Any registration, declaration or filing with, or consent,
      approval, license, permit or other authorization or order by, any
      governmental or regulatory authority, domestic


                                       35
<PAGE>   44
      or foreign, that is required in connection with the valid execution,
      delivery, acceptance and performance by such Limited Partner under this
      Agreement or the consummation by such Limited Partner of any transaction
      contemplated hereby has been completed, made or obtained on or before the
      date hereof.

            (d) There are no actions, suits, proceedings or investigations
      pending or, to the knowledge of such Limited Partner, threatened against
      or affecting such Limited Partner or any of its properties, assets or
      businesses in any court or before or by any governmental department,
      board, agency or instrumentality, domestic or foreign, or any arbitrator
      which could, if adversely determined (or, in the case of an investigation,
      could lead to any action, suit or proceeding, which if adversely
      determined) could reasonably be expected to materially impair such Limited
      Partner's ability to perform its obligations under this Agreement or to
      have a material adverse effect on the consolidated financial condition of
      such Limited Partner; and such Limited Partner has not received any
      currently effective notice of any default, and such Limited Partner is not
      in default, under any applicable order, writ, injunction, decree, permit,
      determination or award of any court, any governmental department, board,
      agency or instrumentality, domestic or foreign, or any arbitrator which
      could reasonably be expected to materially impair such Limited Partner's
      ability to perform its obligations under this Agreement or to have a
      material adverse effect on the consolidated financial condition of such
      Limited Partner.

            (e) Such Limited Partner is acquiring its Interest based upon its
      own investigation, and the exercise by such Limited Partner of its rights
      and the performance of its obligations under this Agreement will be based
      upon its own investigation, analysis and expertise. Such Limited Partner
      is the sole party in interest as to its participation in the Partnership
      and such Limited Partner's acquisition of its Interest is being made for
      its own account for investment and, in particular, such Limited Partner
      has no present agreement, understanding or arrangement to (a) subdivide
      its Interest, (b) hold its Interest in trust for any other Person or (c)
      Dispose of any portion thereof to any other Person except for the
      Disposition of any Partner's Interest to an Affiliate of such Partner.
      Such Limited Partner is a sophisticated investor possessing an expertise
      in analyzing the benefits and risks associated with acquiring investments
      that are similar to the acquisition of its Interest. Prior to the
      acquisition of its Interest, such Limited Partner and its representatives,
      if any, have had the opportunity to obtain ample information concerning
      the Partnership and its proposed activities.

            (f) Such Limited Partner is not, nor will the Partnership as a
      result of such Limited Partner holding an interest therein be, an
      "investment company" as defined in, or subject to regulation under, the
      Investment Company Act of 1940, as amended.

            (g) Exhibit B hereto identifies the Limited Partner Owner for such
      Limited Partner.


                                       36
<PAGE>   45
                                   ARTICLE 10

              DISSOLUTION, WINDING UP AND TERMINATION; CONTINUATION

      10.01 Events of Dissolution.

            (a) The Partnership shall be dissolved and its affairs wound up upon
      the first to occur of the following:

                  (i) the entry of a decree of judicial dissolution under the
            Act;

                  (ii) the Partners determine by Unanimous Consent that the
            Partnership should be dissolved;

                  (iii) an Event of Withdrawal occurs with respect to a General
            Partner;

                  (iv) the sale of all or substantially all of the Partnership's
            interest in the Partnership Property and the collection and
            distribution of all sales proceeds; or

                  (v) the occurrence of any other event which, under the Act,
            causes the dissolution of a limited partnership.

            (b) As used in this Agreement, an "Event of Withdrawal" shall have
      the meaning ascribed to that term in the Act.

            (c) Upon the occurrence of an Event of Withdrawal with respect to a
      General Partner, such General Partner shall cease to be a Partner of the
      Partnership. A General Partner who suffers an event that with the passage
      of the specified period becomes an Event of Withdrawal under the Act shall
      notify the other Partners of the event within thirty (30) days after the
      date of occurrence of the Event of Withdrawal.

            (d) Neither the dissolution nor bankruptcy of any Limited Partner
      nor the admission or substitution of a Person as a Limited Partner in
      accordance with the terms hereof shall dissolve, or be deemed to dissolve,
      the Partnership or cause any interruption in or affect the continued
      existence of the Partnership and its business.

      10.02 Continuation of Business.

            (a) Notwithstanding the provisions of Section 10.01(a) hereof, the
      Partnership shall not be dissolved and shall not be required to be wound
      up if:

                  (i) at the time an Event of Withdrawal occurs, there remains
            at least one (1) General Partner and that General Partner or those
            General Partners elect to


                                       37
<PAGE>   46
            continue the business of the Partnership by written notice to all
            Partners within ninety (90) days after the Event of Withdrawal; or

                  (ii) within ninety (90) days after the Event of Withdrawal,
            all remaining Partners agree in writing to continue the business of
            the Partnership and to the appointment, effective as of the date of
            the Event of Withdrawal, of one or more additional General Partners
            if necessary or desired.

            (b) In the event the Partnership is continued after an Event of
      Withdrawal with respect to a General Partner, the Partnership shall
      promptly after the Event of Withdrawal and as a condition precedent to the
      further continuation of the business of the Partnership after such Event
      of Withdrawal (i) pay to the withdrawing General Partner all sums due and
      owing to the General Partner through the date of withdrawal and (ii)
      assign by duly recordable instruments of assignment an undivided interest
      in the Partnership Property, whether tangible or intangible, real or
      personal, equal to the percentage interest that the withdrawing General
      Partner would share in revenues from the sale of such items of Partner
      ship Property if such items of Property were sold in the ordinary course
      of business on the date the Event of Withdrawal occurred.

      10.03 Agreement of Successor General Partner. A successor General Partner
shall, upon consent to his admission by all of the Limited Partners, be admitted
as a General Partner of the Partnership upon his agreeing to be bound by the
provisions of this Agreement to the same extent and on the same terms and
conditions as the then General Partner, if any, or, if none, as the General
Partner most recently withdrawn. Any such successor General Partner shall, as a
condition of receiving any Interest, also agree to be bound by any contracts,
leases, instruments or other documents theretofore executed and delivered on
behalf of the Partnership to the same extent and on the same terms and
conditions as specified in the preceding sentence.

      10.04 Liquidation. Upon dissolution of the Partnership, the General
Partner (or, if there shall not be any remaining General Partners, a special
liquidator [herein called the "Liquidator"] appointed by a Required Interest)
shall proceed with the winding up of the Partnership and shall distribute the
assets of the Partnership in the following order of priority:

            (a) To creditors, including Partners who are creditors, to the
      extent permitted by law, in satisfaction of liabilities of the Partnership
      (whether by payment or the making of reasonable provision for payment
      thereof) other than liabilities for which reasonable provision for payment
      has been made and other than liabilities to Partners for distributions;

            (b) To the setting up of any reserve which such General Partner (or
      the Liquidator, where applicable) shall reasonably deem advisable to
      provide for any contingent or unforeseen liabilities or obligations of the
      Partnership;

            (c) To the Partners and former Partners in satisfaction of
      liabilities for distributions; and


                                       38
<PAGE>   47
            (d) all remaining assets of the Partnership shall be distributed to
      the Partners as follows:

            (i) the liquidator may sell any or all Property, including to
      Partners, and any resulting gain or loss from each sale shall be computed
      and allocated to the capital accounts of the Partners;

            (ii) with respect to all Property that has not been sold, the fair
      market value of that Property shall be determined and the Capital Accounts
      of the Partners shall be adjusted to reflect the manner in which the
      unrealized income, gain, loss and deduction inherent in Property that has
      not been reflected in the Capital Accounts previously would be allocated
      among the Partners if there were a taxable disposition of that Property
      for the fair market value of that Property on the date of distribution;
      and

            (iii) Property, including cash, shall be distributed to the
      Partners, in proportion to their positive Capital Accounts as of the date
      of such distribution, after giving effect to all contributions,
      distributions and allocations for all periods.

      All distributions in kind to the Partners shall be made subject to the
liability of each distributee for costs, expenses and liabilities theretofore
incurred or for which the Company has committed prior to the date of termination
and those costs, expenses and liabilities shall be allocated to the distributee
pursuant to this Section 10.04. The distribution of cash and/or Property to a
Partner in accordance with the provisions of this Section 10.04 constitutes a
complete return to the Partner of its Capital Contributions and a complete
distribution to the Partner of its Interest and all the Partnership's Property.
To the extent that a Partner returns funds to the Partnership, it has no claim
against any other Partner for those funds.

At the expiration of such period of time as the General Partner (or, where
applicable, the Liquidator) shall deem advisable, the remaining balance of any
reserve established in accordance with subsection 10.04(b) shall be distributed
in the manner set forth in subsection 10.04(d).

      10.05 Distributions in Kind. In the event the General Partner (or, where
applicable, the Liquidator) determines that it is necessary or desirable upon
dissolution to make a distribution of any Property of the Partnership in kind,
such Property shall be transferred and conveyed on the basis of the fair market
value thereof to the Partners or their assignees, so as to vest in each of them
an undivided interest, as tenants-in-common, in the whole of such Property
proportionate to their positive Capital Account balances. Any Partnership
Property distributed in kind shall be subject to such liens, encumbrances and
restrictions that affect such Partnership Property on the date of distribution
and will be subject to and operated in accordance with any operating agreements
then in effect.


                                       39
<PAGE>   48
                                   ARTICLE 11

                       AMENDMENT OF PARTNERSHIP AGREEMENT;
                              MEETINGS; RECORD DATE

      11.01 Amendments to be Adopted Solely by General Partner. The General
Partner (pursuant to this Section 11.01 and its power of attorney from the
Limited Partners), without the consent of any Limited Partner, may amend any
provision of this Agreement and execute, swear to, acknowledge, deliver, file
and record whatever documents may be required in connection therewith, to
reflect:

            (a) a change in the name of the Partnership, the location of the
      principal place of business of the Partnership, the registered office of
      the Partnership or the registered agent of the Partnership;

            (b) the admission or removal of any Partner in accordance with this
      Agreement;

            (c) a change in any Limited Partner's Capital Contribution;

            (d) a change that is necessary to qualify the Partnership as a
      limited partnership under the laws of any state or any change that is
      necessary or advisable in the opinion of the General Partner to ensure
      that the Partnership will not be treated as an association taxable as a
      corporation for federal income tax purposes;

            (e) the cure of any ambiguity in this Agreement or to correct or
      supplement any provisions hereof which may be inconsistent with any other
      provision hereof;

            (f) amendments to the provisions of this Agreement in response to
      changes in the Code or regulations thereunder or other developments in the
      law applicable to the taxation of the Partnership or its Partners, if the
      General Partner concludes in good faith that such amendments are in the
      overall best interests of the Partners; provided, however, that the
      General Partner shall be under no obligation to make any such amendment;
      and

            (g) any other amendments similar to the foregoing.

      11.02 Amendments to be Adopted with Consent of Limited Partners. Except as
provided in Section 11.01 hereof, all amendments to this Agreement shall be made
in accordance with the following requirements:

            (a) Amendments to this Agreement may be proposed by the General
      Partner or by Limited Partners holding at least 10% of the Units.

            (b) Following any proposal of an amendment, the General Partner
      shall, within fifteen (15) days after receipt of such proposal, mail to
      all Partners a verbatim statement of


                                       40
<PAGE>   49
      the proposed amendment and any alternative or additional proposal by the
      General Partner. The General Partner may include in such submission its
      recommendation as to the proposed amendments and may (but shall not be
      required to) solicit the proxies of the Limited Partners to vote on such
      proposals or any other matter which may come before the meeting at which
      such proposal(s) will be voted upon. Such proposed amendment may be voted
      upon by the Limited Partners by written vote in lieu of a meeting or at a
      meeting in person or by proxy, as specified by the General Partner in such
      notice of proposed amendment. The General Partner must include in such
      submission the date on which the meeting will be held to vote on such
      proposed amendment or the date by which written votes must be received by
      the General Partner. Such date must be not less than thirty (30) days nor
      more than forty-five (45) days after the date of mailing of such
      submission to the Limited Partners; provided, however, if voting is by
      written consent, the General Partner may deem such proposed amendment to
      be approved or rejected before the expiration of such fifteen (15)
      day-period if the General Partner has received the unanimous consent of
      the Limited Partners to approve or reject the proposed amendment.

            (c) Except as otherwise provided in this Agreement, a Required
      Interest shall be required to approve or disapprove any proposal before
      the Partners. If the General Partner determines that voting on such
      proposal(s) shall be by written vote in lieu of a meeting, and the written
      vote of a Limited Partner in the form submitted to the Limited Partner by
      the General Partner is not actually received by the General Partner on or
      before the date such written vote is due, such Limited Partner shall be
      deemed to have voted on the proposal(s) in accordance with the
      recommendation(s), if any, of the General Partner. If no recommendation of
      the General Partner was submitted to the Limited Partners, the failure to
      timely vote in the form submitted to a Limited Partner shall constitute a
      vote against all proposals.

      11.03 Consent of General Partner Required. Notwithstanding the foregoing
provisions of this Article 11, the consent of the General Partner shall be
required for any amendment which would:

            (a) change the General Partner's sharing of costs and revenues or
      any item of income, gain, loss, deduction or credit;

            (b) increase or diminish the General Partner's duties under this
      Agreement or the General Partner's liabilities, whether fixed or
      contingent;

            (c) modify the provisions of this Agreement relating to removal or
      replacement of the General Partner;

            (d) have or is reasonably expected to have a materially adverse
      effect on the General Partner; or

            (e) amend this Section 11.03.


                                       41
<PAGE>   50
      11.04 Meetings. Meetings of the Partners may be called by the General
Partner or by Limited Partners owning at least 10% of the Units. Any call for a
meeting by Limited Partners shall be submitted in writing to the General Partner
and such call shall contain a reasonably detailed description of matters to be
brought before the Partners at such meeting. Within twenty (20) days after
receipt of such a call from Limited Partners, the General Partner shall mail a
notice of the meeting to the Limited Partners, which notice shall contain a
reasonably detailed description of matters to be brought before the Partners at
such meeting. The General Partner may (but shall not be required to) solicit the
proxies of Limited Partners in connection with any meetings. A meeting shall be
held at a reasonable time and convenient place on a date not less than fifteen
(15) nor more than sixty (60) days after the mailing of notice of the meeting.
The General Partner shall select the time and place of the meeting. For purposes
of this Section 11.04, any location in the continental United States shall be
deemed a convenient meeting place. Limited Partners may vote either in person or
by proxy at any meeting. Action at any such meeting shall be limited to those
matters specified in the notice of meeting. The presence, in person or by proxy,
of a Required Interest shall constitute a quorum, and, except as otherwise
provided in this Agreement, the affirmative vote, in person or by proxy, of a
Required Interest shall be required to approve any action duly proposed at such
meeting. The presence of a Limited Partner at any meeting, whether in person or
by proxy, shall constitute a waiver of any irregularity in the notice of meeting
or lack of notice, except where the Limited Partner attends a meeting for the
sole and expressed purpose of objecting to the transaction of any business on
the ground that the meeting is not lawfully called or convened. Any such
objection shall be submitted in writing to the General Partner at such meeting
and shall specifically state the grounds of objection.

      11.05 Action Without a Meeting. Any action that may be taken at a meeting
of the Limited Partners may be taken without a meeting, without prior notice and
without a vote, if a consent or consents in writing setting forth the action so
taken shall be signed and dated by the General Partner (if its consent to such
action is required) and each of the Limited Partners. The notice and voting
procedures of Section 11.02(b) hereof relating to submission of amendment
proposals and voting thereon by written consent in lieu of a meeting shall also
apply to the submission of and voting on proposals pursuant to this Section
11.05. No written consent shall be effective to take the action that is the
subject to the consent unless, within sixty (60) days after the date of the
earliest dated consent delivered to the General Partner in the manner required
by this Section 11.05, a consent or consents signed and dated by the General
Partner (if required) and each of the Limited Partners are delivered to the
General Partner by delivery to its registered office or its principal place of
business. A telegram, telex, cablegram or similar transmission by a Partner
shall be regarded as signed by the Partner for purposes of this Section.

      11.06 Record Date. For the purpose of determining Partners entitled to
notice of or to vote at any meeting of Partners or any reconvening thereof or by
consent, or the Partners and their assignees entitled to receive payment of any
distribution, or in order to make a determination of Partners and their
assignees for any other proper purpose, the General Partner may fix in advance a
date as the record date for any such determination of Partners and assignees,
such date in any case to be not more than sixty (60) days (and in case of a
meeting of Partners or solicitation of consents not less than ten (10) days)
prior to the date on which the particular action requiring such


                                       42
<PAGE>   51
determination of Partners and assignees is to be taken or the first solicitation
of consents in writing. If no record date is fixed for the determination of
Partners entitled to notice of or to vote at a meeting of Partners or by
consent, or of the Partners and assignees entitled to receive payment of a
distribution, the date on which the notice of the meeting is mailed, the date
of the first solicitation of consents in writing or the date on which the
General Partner declares such distribution, as the case may be, shall be the
record date for such determination of Partners or assignees.

                                   ARTICLE 12

                               DISPUTE RESOLUTION

      12.01 Disputes. This Article 12 shall apply to any dispute arising under
or related to this Agreement (whether arising in contract, tort or otherwise,
and whether arising at law or in equity), including (a) any dispute regarding
the construction, interpretation, performance, validity or enforceability of any
provision of this Agreement or whether any Person is in compliance with, or in
breach of, any provisions of this Agreement and (b) the applicability of this
Article 12 to a particular dispute (collectively, a "Dispute").

      12.02 Negotiations to Resolve Disputes. The Partners shall endeavor to
resolve any Dispute in a prompt and equitable manner. In the event a Dispute
arises which the Partners are unable to resolve, the Partners shall, prior to
the initiation of any claim or cause of action, each appoint an officer or
representative that has settlement authority to meet (in person or by telephone
conference) in an effort to resolve the Dispute equitably, in good faith and as
quickly as reasonably possible. No settlement shall be binding until reduced to
writing and signed by the Partners. The responsibility of these representatives
shall be to resolve the matter or propose a method of resolving the matter, if
possible. If the Dispute is not settled or resolved by the earlier of (a) sixty
(60) days following the first meeting of the representatives and (b) at such
time as the representatives unanimously agree that a resolution of the Dispute
is not possible, then the Partners may proceed as set forth in Section 12.03
hereof.

      12.03 Arbitration. Subject to the provisions of Section 12.02 hereof, any
Dispute shall be settled by binding arbitration administered by the American
Arbitration Association (the "AAA") under its Commercial Arbitration Rules, and
judgment on the award rendered by the arbitrator(s) may be entered in any court
of competent jurisdiction. All Partners further agree to waive the
fifty-thousand dollar ($50,000) maximum claim amount applicable to the Expedited
Procedures contained in the Commercial Arbitration Rules, and agree to submit to
such Expedited Procedures, along with the additional discovery-related rules
outlined below, in all disputes subject to arbitration hereunder. In no event
may the initiation of arbitration by written submission to the AAA be given more
than one (1) year after the date the Dispute was first asserted in writing to
the other Partner in accordance with Section 12.02 hereof. The Partners shall
adhere to the following schedule for exchange of information upon commencement
of arbitration under the Commercial Arbitration Rules:


                                       43
<PAGE>   52
            (a) Within seven (7) days of the service by the responding Partner
      of an answering statement upon the complaining Partner, the complaining
      Partner shall serve upon the responding Partner a copy of each document in
      possession of the complaining Partner and a list of any witnesses,
      excluding those documents and witnesses to be used for cross-examination
      or rebuttal, that the complaining Partner intends to rely upon at the
      arbitration;

            (b) Within thirty (30) days of the service by the responding Partner
      of an answering statement upon the complaining Partner, the responding
      Partner shall provide a list of any witnesses it intends to call at
      arbitration and a list of all documents it intends to rely on at
      arbitration, excluding those documents it intends to rely on at
      arbitration, excluding those documents and witnesses to be used for
      cross-examination or rebuttal;

            (c) Any Partner may serve written requests for information and
      documents (the "Information Request") upon another Partner within thirty
      (30) days of the filing of the answering statement, subject to the
      following limitations:

                  (i) Each Partner may serve not more than one (1) set of
            interrogatories limited to ten (10) items;

                  (ii) Each Partner may depose the other Partner's expert
            witnesses, if any, who will be called to testify at the hearing,
            plus four (4) fact witnesses without regard to whether they will be
            called to testify. Each Partner will be entitled to a total of not
            more than twenty-four (24) hours of depositions of the other
            Partner's witnesses, including, but not limited to, the witnesses
            referred to herein. All depositions to be taken by a Partner are to
            be scheduled and completed within one hundred twenty (120) days of
            the filing of the answering statement.

            (d) Information Requests, except as otherwise provided herein, shall
      be satisfied or objected to within twenty (20) days from the date of
      service of the Information Request;

            (e) Any response to objections to an Information Request shall be
      served within ten (10) days of receipt of the objection;

            (f) Upon the written request of a Partner whose information request
      is unsatisfied, the matter will be considered by the arbitrator(s) at a
      preliminary hearing held in accordance with the Commercial Arbitration
      Rules.


                                       44
<PAGE>   53
                                   ARTICLE 13

                               GENERAL PROVISIONS

      13.01 Payments and Offset. Whenever the Partnership is to pay any sum to
any Partner, any amounts that Partner owes the Partnership may be deducted from
that sum before payment. If any payment due hereunder, including any Capital
Contribution, is not made when due, it shall accrue interest at the Base
Interest Rate.

      13.02 Notices. Except as expressly set forth to the contrary in this
Agreement, all notices, requests, or consents provided for or permitted to be
given under this Agreement must be in writing and must be given either by
depositing that writing in the United States mail, addressed to the recipient,
postage paid, and registered or certified with return receipt requested or by
delivering that writing to the recipient in person, by courier or by facsimile
transmission; a notice request, or consent given under these Regulations is
effective on receipt by the Person who is to receive it. Whenever any notice is
required to be given by law or this Agreement, a written waiver thereof, signed
by the Person entitled to notice, whether before or after the time stated
therein, shall be deemed equivalent to the giving of such notice.

If to the General Partner
or the Partnership:                      Millennium Pipeline Management Company,
                                         L.L.C.
                                         12801 Fair Lakes Parkway
                                         P.O. Box 10146
                                         Fairfax, Virginia 22030
                                         Attn: Mr. David C. Pentzien, Chairman
                                         Telephone: (703) 227-3223
                                         Telecopy: (304) 227-3326

If to Columbia:                          Columbia Gas Transmission Corporation
                                         12801 Fair Lakes Parkway
                                         P.O. Box 10146
                                         Fairfax, Virginia 22030
                                         Attn: Mr. David C. Pentzien
                                         Telephone: (703) 227-3223
                                         Telecopy: (304) 227-3326

If to MCN:                               MCNIC Millennium Company
                                         City Place I
                                         185 Asylum Street, 32nd Floor
                                         Hartford, CT 06103
                                         Attn: Mr. Mike Feodorov
                                         Telephone: (860) 275-6460
                                         Telecopy: (860) 275-6245


                                       45
<PAGE>   54
If to TransCanada:                       TransCanada PipeLine USA Ltd.
                                         TransCanada PipeLines Tower
                                         511 5th Avenue, SW
                                         Calgary, Alberta
                                         Canada T2P 3Y6
                                         Attn: Mr. Brian Fowler
                                         Telephone: (403) 267-1908
                                         Telecopy: (403) 267-8573

If to Westcoast:                         Westcoast Energy (U.S.) Inc.
                                         50 Keil Drive North
                                         Chatham, Ontario
                                         Canada N7M 5M1
                                         Attn: Mr. John Wolnik
                                         Telephone: (519) 436-4567
                                         Telecopy: (519) 436-4521

      13.03 Ratification. The Limited Partners hereby ratify, approve, adopt and
confirm as an act of the Partnership, all lawful acts taken by and on behalf of
the Partnership prior to the date hereof (a) by the General Partner and (b)
pursuant to the MOU by the management committee or its members or chairman
established under the MOU, whether such action was taken in the name of the
Partnership or otherwise, including the filing of the documents pursuant to
which application was made on behalf of the Partnership for the regulatory
authorizations from the FERC for authority to construct, own, operate and
maintain the Millennium Pipeline System and for the authority to provide natural
gas transmission services using the Millennium Pipeline System.

      13.04 Execution and Counterparts. This Agreement may be executed in any
number of counterparts with the same effect as if all parties hereunder had
signed the same document. All counterparts shall be construed together and shall
constitute one agreement.

      13.05 Waiver of Partition. Each Partner hereby irrevocably waives during
the term of the Partnership any right that it or he may have to maintain any
action for partition with respect to any Partnership Property.

      13.06 Governing Law, Successors, Severability. The internal affairs of the
Partnership and the relative rights of the parties to this Agreement shall be
governed by the laws of the State of Delaware, as such laws are applied by
Delaware courts to agreements entered into and to be performed in Delaware by
and between residents of Delaware, and shall, subject to the restrictions on
transferability set forth herein, bind and inure to the benefit of the legal
representatives, successors and assigns of the parties hereto. All other rights
and remedies shall be governed by the laws of the State of Delaware. If any
provision of this Agreement shall be held to be invalid, the remainder of this
Agreement shall not be affected thereby.


                                       46
<PAGE>   55
      13.07 Entire  Agreement; Acknowledgment.

            (a) This Agreement constitutes the entire agreement of the Partners
      relating to the Partnership. This Agreement supersedes any prior agreement
      or understandings among them, oral or written, including the MOU.

            (b) The Limited Partners and the General Partner expressly
      acknowledge that, without limiting the effect of subsection 13.07(a), the
      obligations of each Limited Partner shall be limited to those expressly
      contained in this Agreement, the Regulations of Millennium Pipeline
      Management Company, L.L.C. and any Project Agreements to which such
      Limited Partner is a party, and there are no additional express or implied
      obligations or understandings of the said Limited Partner or any of its
      Affiliates in respect of the Millennium Pipeline System, fiduciary or
      otherwise.

      13.08 No Waiver. The failure of any Partner to seek redress for violation,
or to insist on strict performance, of any covenant or condition of this
Agreement shall not prevent a subsequent act which would have constituted a
violation from having the effect of an original violation.

      13.09 Legends. If certificates are issued evidencing a Limited Partner's
Interest in the Partnership, each such certificate shall bear such legends as
may be required by applicable federal and state laws, or as may be deemed
necessary or appropriate by the General Partner to reflect restrictions upon
transfer contemplated herein.

      13.10 Presumptions. Any act or omission performed or omitted by the
General Partner or an Affiliate of the General Partner on advice of legal
counsel or an independent consultant who has been employed or retained by the
Partnership shall be presumed to have been performed or omitted in good faith.
The termination of any action, suit or proceeding by judgment, order or
settlement shall not, of itself, create a presumption that any such party did
not act in good faith and in the best interests of the Partnership.

      13.11 Time of Essence. Time shall be of the essence in the performance of
this Agreement.

                            [SIGNATURE PAGES FOLLOW]


                                       47
<PAGE>   56
      IN WITNESS WHEREOF, this Agreement is executed as of the date first set
forth above.


                                 GENERAL PARTNER:

                                 Millennium Pipeline Management Company, L.L.C.,
                                 a Delaware limited liability company


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________










                   [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]


                         THIS IS A SIGNATURE PAGE TO THE
                       AGREEMENT OF LIMITED PARTNERSHIP OF
                        MILLENNIUM PIPELINE COMPANY, L.P.
<PAGE>   57
      IN WITNESS WHEREOF, this Agreement is executed as of the date first set
forth above.

                                 LIMITED PARTNERS:

                                 Columbia Gas Transmission Corporation,
                                 a Delaware corporation


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________










                   [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]


                         THIS IS A SIGNATURE PAGE TO THE
                       AGREEMENT OF LIMITED PARTNERSHIP OF
                        MILLENNIUM PIPELINE COMPANY, L.P.
<PAGE>   58
      IN WITNESS WHEREOF, this Agreement is executed as of the date first set
forth above.

                                 MCNIC Millennium Company,
                                 a Michigan corporation


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________










                   [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]


                         THIS IS A SIGNATURE PAGE TO THE
                       AGREEMENT OF LIMITED PARTNERSHIP OF
                        MILLENNIUM PIPELINE COMPANY, L.P.
<PAGE>   59
      IN WITNESS WHEREOF, this Agreement is executed as of the date first set
forth above.

                                 TransCanada PipeLine USA Ltd.,
                                 a Nevada corporation


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________










                   [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]


                         THIS IS A SIGNATURE PAGE TO THE
                       AGREEMENT OF LIMITED PARTNERSHIP OF
                        MILLENNIUM PIPELINE COMPANY, L.P.
<PAGE>   60
      IN WITNESS WHEREOF, this Agreement is executed as of the date first set
forth above.

                                 Westcoast Energy (U.S.) Inc.,
                                 a Delaware corporation


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________


                                 By:__________________________________________
                                 Printed Name:________________________________
                                 Title:_______________________________________










                         THIS IS A SIGNATURE PAGE TO THE
                       AGREEMENT OF LIMITED PARTNERSHIP OF
                        MILLENNIUM PIPELINE COMPANY, L.P.
<PAGE>   61
                                    EXHIBIT A

 INITIAL PARTNERS, UNITS, PARTNERSHIP INTEREST AND INITIAL CAPITAL CONTRIBUTION

                                LIMITED PARTNERS

<TABLE>
<CAPTION>
                              LIMITED        LIMITED
          LIMITED             PARTNER      PARTNERSHIP        INITIAL CAPITAL
          PARTNER              UNITS         INTEREST          CONTRIBUTION
          -------              -----         --------          ------------
<S>                           <C>          <C>                <C>
Columbia                      4702.5           47.5%           US$6,748,969

MCN                           1039.5           10.5%           US$1,491,877

TransCanada                     2079           21.0%           US$2,983,755

Westcoast                       2079           21.0%           US$2,983,755
                              ------         ------
                                9900          100.0%*
</TABLE>


                                 GENERAL PARTNER

<TABLE>
<CAPTION>
                              GENERAL        GENERAL
          GENERAL             PARTNER      PARTNERSHIP        INITIAL CAPITAL
          PARTNER              UNITS         INTEREST          CONTRIBUTION
          -------              -----         --------          ------------
<S>                           <C>          <C>                <C>
Millennium Pipeline             100           100.0%**           US$143,519
Management Company, L.L.C.
</TABLE>

- ----------
*     The Limited Partners, collectively, own 99.0% of the Partnership
      Interests.

**    As owner of 100% of the General Partnership Interest, the General Partner
      owns 1.0% of the Partnership Interests.
<PAGE>   62
                                    EXHIBIT B

                             LIMITED PARTNER OWNERS


<TABLE>
<CAPTION>
LIMITED PARTNER             LIMITED PARTNER OWNER(S)        OWNERSHIP PERCENTAGE
- ---------------             ------------------------        --------------------
<S>                <C>                                      <C>
Columbia           Columbia Energy Group,                          100%
                   a Delaware corporation

MCN                MCNIC Pipeline and Processing Company,          100%
                   a Michigan corporation

TransCanada        TransCanada Pipelines Limited,                  100%
                   a Canada corporation

Westcoast          Westcoast Energy, Inc.,                         100%
                   a Delaware corporation
</TABLE>

<PAGE>   1
                                                                  Exhibit 10CH





                            CONTRIBUTION AGREEMENT



                                    BETWEEN







                     COLUMBIA GAS TRANSMISSION CORPORATION



                                      AND



                       MILLENNIUM PIPELINE COMPANY, L.P.





                           DATED AS OF JULY 31, 1998
<PAGE>   2
                                     INDEX

<TABLE>
<S>                                                                            <C>
ARTICLE I
DEFINITIONS .............................................................      1

ARTICLE II
CONTRIBUTION OF ASSETS ..................................................      3

ARTICLE III
PROCEEDS, EXPENSES AND TAXES ............................................      4

ARTICLE IV
OPERATIONS AND FACILITIES ...............................................      5

ARTICLE V
DISCLAIMER OF ALL WARRANTIES ............................................      5

ARTICLE VI

ENVIRONMENTAL MATTERS ...................................................      6

ARTICLE VII
REPRESENTATIONS AND WARRANTIES ..........................................      8

ARTICLE VIII
INDEMNIFICATION .........................................................     10

ARTICLE IX
CONDITIONS PRECEDENT AND TERMINATION ....................................     11

ARTICLE X
TRANSFER DATE ...........................................................     13

ARTICLE XI
OBLIGATIONS AFTER THE TRANSFER DATE .....................................     14

ARTICLE XII
DOCUMENTATION ...........................................................     15

ARTICLE XIII
MISCELLANEOUS PROVISIONS ................................................     15
</TABLE>

Schedule I  -     Actions, Suits, Etc.


                                       -i-
<PAGE>   3
                             CONTRIBUTION AGREEMENT


      THIS CONTRIBUTION AGREEMENT (this "Agreement") dated as of the 31st day of
July, 1998, is by and between COLUMBIA GAS TRANSMISSION CORPORATION, a Delaware
corporation ("Columbia"), and Millennium Pipeline Company, L.P., a Delaware
limited partnership ("Millennium"). Columbia and Millennium may be referred to
herein individually as a "Party" or collectively as the "Parties".

                                    RECITALS:

      A. Columbia owns the Assets located in the State of New York and the
Commonwealth of Pennsylvania.

      B. Columbia is a limited partner in Millennium, and pursuant to the
Agreement of Limited Partnership of Millennium Pipeline Company, L.P. (the "LP
Agreement"), Columbia has the right to contribute the Assets to Millennium as
partial consideration for Columbia's limited partnership interest in Millennium.

      C. The Parties desire to set forth the terms and conditions pursuant to
which the Assets will be contributed by Columbia to Millennium.

      NOW THEREFORE, in consideration of the premises and of the respective
covenants, representations and warranties herein contained, and other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the Parties hereto, intending to be legally bound, do hereby
covenant and agree as follows:

                                  ARTICLE I.
                                  DEFINITIONS

      1.1 Capitalized terms used in this Agreement shall have the following
meanings:

            "Abandonment Application" shall mean Columbia's application filed
with the FERC in Docket No. CP 98-151-000 for authority, inter alia, to abandon
the Assets.

            "Agreement" shall have the meaning set forth in the introductory
paragraph hereof.

            "AOC" shall mean the Administrative Order on Consent for Removal
Actions, issued by the U.S. Environmental Protection Agency, Regions II, III, IV
and V to Columbia, EPA Docket No. III-94-35-DC, with an effective date of
February 23, 1995, as amended or supplemented.

            "Assessment Report" shall mean the report prepared by Columbia and
approved by EPA regarding the assessment and/or characterization of sites as
required by the AOC, including any remedial recommendations.
<PAGE>   4
            "Assets" shall mean (1) all of the pipeline segments, measuring
stations and compressor stations listed on pages 3, 4 and 5 of Exhibit Z-1 of
the Abandonment Application, as amended or supplemented (the "Facilities"); (2)
all appurtenant structures, facilities, equipment, supplies, machinery, fixtures
and other items of tangible personal property located at or used to operate,
maintain or manage the Facilities, including compression, measuring, regulating,
communications, data, computer, laboratory and other equipment, tools, furniture
and supplies; (3) all improvements to or replacements of the Facilities prior to
the Effective Time, including any overpressure protection facilities constructed
by Columbia at or adjacent to the Facilities pursuant to Section 2.55 of the
FERC's NGA regulations; (4) all of the real estate owned by Columbia on which
any of the Facilities are situated or which is necessary for the operation and
maintenance of the Facilities; (5) all of Columbia's right, title and interest
in any easements, rights-of-way, leases or other interests in real property on
which any Facilities are situated or which are necessary for the operation and
maintenance of the Facilities; (6) any and all assignable rights which Columbia
may have pursuant to any easements, rights-of-way, leases or other interests in
real property to construct, operate and maintain a natural gas pipeline and
related facilities on the route approved in the Certificate Approval, as it may
be amended; (7) all of the real estate owned by Columbia on which any of the
pipeline segments listed on pages 1 and 2 of Exhibit Z-1 of the Abandonment
Application, as amended or supplemented (the "Abandoned Facilities"), are
situated; (8) all of Columbia's right, title and interest in any easements,
rights-of-way, leases or other interests in real property on which any of the
Abandoned Facilities are situated; and (9) all assignable rights which Columbia
may have pursuant to any easements, rights-of-way, leases or other interests in
real property to construct, operate and maintain a natural gas pipeline and
related facilities adjacent to the Abandoned Facilities.

            "Certificate Approval" shall mean the Final Order by FERC on
Millennium's certificate application pursuant to Section 7(c) of the NGA
granting the application and containing terms acceptable to Millennium.

            "Columbia" shall have the meaning set forth in the introductory
paragraph hereof.

            "Corridor Assets" shall mean the Assets described in subsections
(7), (8) and (9) of the definition of Assets.

            "COWP" shall mean the Work Plan for Construction and Operations at
Work Scope List Facilities, revised March 3, 1995, or the then-current version
of the COWP as approved by EPA.

            "Effective Time" shall mean 11:59 p.m., Eastern Time, on the date
immediately preceding the date on which the Millennium Pipeline System commences
service.

            "Environmental Assessment" shall mean the assessment and/or
characterization of locations as required by the AOC.

            "EPA" shall mean the United States Environmental Protection Agency
and any successor agency.


                                        2
<PAGE>   5
            "FERC" shall mean the Federal Energy Regulatory Commission and any
successor agency.

            "Final Order" shall mean any order no longer subject to further
proceedings before the FERC. An order shall be deemed to be a Final Order as of
the date rehearing is denied or the date on which the right to seek rehearing
expires.

            "LP Agreement" shall have the meaning set forth in the recitals
hereof.

            "Millennium" shall have the meaning set forth in the introductory
paragraph hereof.

            "Millennium Pipeline System" shall mean the pipeline system and
facilities authorized in the Certificate Approval.

            "Net Book Value" shall mean with respect to the Assets the net book
value as determined in accordance with FERC accounting standards and
requirements, as the same are modified from time to time.

            "NGA" shall mean the Natural Gas Act, 15 U.S.C.A. Section717, et
seq.

            "Response Action" shall mean any action required by the EPA pursuant
to the AOC.

            "Response Action Completion Final Report" shall mean that document
and/or documents which verify Columbia's performance of Response Actions
required by the AOC and is/are approved by EPA.

            "Response Action Work Plan" shall mean that document and/or
documents that is/are approved by the EPA and which describe(s) the manner in
which Response Actions required by the AOC are to be carried out.

            "Transfer Date" shall have the meaning set forth in Section 10.1
hereof.

            "Work Scope List" or "WSL" shall mean the document titled "Work
Scope List," dated March 23, 1995, submitted by Columbia to EPA pursuant to the
AOC and conditionally approved by EPA on July 12, 1995, as amended or
supplemented.

                                   ARTICLE II.
                             CONTRIBUTION OF ASSETS

      2.1 Upon and subject to the terms, conditions, representations and
warranties set forth in this Agreement, and except as provided in Article VI
hereof, Columbia agrees to assign, transfer and convey the Assets to Millennium
and Millennium agrees to take delivery of and accept the assignment, conveyance
and transfer of the Assets on the Transfer Date but effective for all purposes
as of the Effective Time. Notwithstanding the foregoing, Columbia shall, if
requested by Millennium, assign, transfer and convey certain portions of the
Assets to Millennium prior to the


                                        3
<PAGE>   6
Transfer Date. In the event of an assignment, transfer and conveyance prior to
the Transfer Date, (a) the Net Book Value of that portion of the Assets
assigned, transferred and conveyed shall be determined as of the Effective Time
regardless of the actual date of the assignment, transfer and conveyance, (b)
Columbia shall have until the Transfer Date to be in compliance with
representations contained in Section 7.1(d) hereof, (c) the conditions precedent
set forth in Section 9.1(d) hereof shall have occurred and (d) the indemnities
of the Parties contained in Sections 6.1(b) and (c) and in Article 8 hereof with
respect to such Assets shall commence as of the actual date of the assignment,
conveyance and transfer of such Assets to Millennium.

      2.2 The assignment, transfer and conveyance of the Assets shall be subject
to the limitations and restrictions, if any, contained in such documents of
title, assignment and other similar documents necessary to assign, transfer and
convey the Assets to Millennium. The Assets shall be assigned, transferred and
conveyed to Millennium subject to the representations and warranties set forth
herein. The transfer documents shall reflect Columbia's exceptions to title and
reservation of rights as approved by Millennium.

      2.3 The value of the Assets for purposes of determining the consideration
for Columbia's contribution to Millennium pursuant to the LP Agreement shall be
the Net Book Value of the Assets as of the Effective Time.

      2.4 Anything in this Agreement to the contrary notwithstanding, Millennium
(a) shall, if requested by Columbia, assign, transfer and convey to Columbia the
Corridor Assets, at a mutually agreed value, which Columbia represents are
necessary for Columbia to maintain natural gas transportation services for its
shippers and (b) shall be entitled, at its sole discretion, to assign, transfer
and convey to Columbia at no charge or cost to Columbia at any time within two
years of the Effective Time any of the Corridor Assets which Millennium chooses
not to retain, in which event Columbia agrees to take delivery of and accept
such Corridor Assets.

                                 ARTICLE III.
                         PROCEEDS, EXPENSES AND TAXES

      3.1 Ownership, operation and risk of loss of the Assets shall, except to
the extent that rights have been retained by Columbia pursuant to Section 2.2
herein, pass from Columbia to Millennium as of the Effective Time. If Columbia,
at any time subsequent to the Effective Time, should receive any revenues or
other proceeds attributable to any service provided through or by or related to
the Assets occurring after the Effective Time, Columbia shall promptly remit all
such revenues or proceeds to Millennium. If Millennium at any time subsequent to
the Effective Time should receive any revenues or other proceeds attributable to
any service provided through or by or related to the Assets for periods prior to
the Effective Time, Millennium shall promptly remit all such revenues or
proceeds to Columbia.

      3.2 Except for Columbia's environmental obligations contemplated in
Article VI hereof, Millennium shall be responsible for the payment of all costs
and expenses, including expenses for all operating and capital expenses
attributable to the Assets from and after the Effective Time.


                                        4
<PAGE>   7
      3.3 Columbia shall be reimbursed by Millennium for any expenses paid by
Columbia with respect to the Assets for non-environmental matters relating to
the period of time on and after the Effective Time.

      3.4 Any and all excise or transfer taxes due and payable as a result of
the assignment, transfer and conveyance of the Assets and all sales taxes
relating to the assignment, transfer and conveyance of Assets and any recording
fees shall be paid by Millennium.

      3.5 All real estate, property and other use or ad valorem taxes assessed
against the Assets for the calendar year in which the Transfer Date occurs shall
be paid by Columbia when due and payable. Millennium shall reimburse Columbia
for Millennium's pro rata share of such taxes for the tax period which includes
the Transfer Date within thirty (30) days after receipt of a request from
Columbia. This provision shall survive the final settlement provisions of
Article XI hereof.

      3.6 For purposes of federal, state and local income and franchise taxes
and other similar taxes, it is the express intent of the Parties that all of
Columbia's right, title and interest in the Assets shall pass to Millennium as
of the Effective Time, that Millennium shall bear all such taxes attributable to
the Assets accruing on and after the Effective Time and that Columbia shall bear
all taxes attributable to the Assets accruing prior to the Effective Time.

                                  ARTICLE IV.
                          OPERATIONS AND FACILITIES

      4.1 Columbia agrees that until the Assets are assigned, transferred and
conveyed to Millennium it shall continue to maintain the Assets in their present
operating condition (reasonable wear and tear excepted) in accordance with
Columbia's standard maintenance practices.

      4.2 Columbia shall keep in full force and effect its existing property and
liability insurance on the Assets, subject to self-retention limits, until the
Transfer Date.

      4.3 Unless (a) this Agreement is terminated pursuant to Section 9.4 hereof
or (b) Millennium elects not to proceed with its proposed project, Columbia
shall not withdraw the Abandonment Application or amend the Abandonment
Application in any manner which could reasonably be expected to have an adverse
effect on Millennium.

                                  ARTICLE V.
                         DISCLAIMER OF ALL WARRANTIES

      SUBJECT TO THE PROVISIONS OF ARTICLE VI HEREOF, THE EXPRESS
REPRESENTATIONS OF COLUMBIA CONTAINED IN ARTICLE VII HEREOF AND IN THE DOCUMENTS
WHICH ASSIGN, TRANSFER AND CONVEY THE ASSETS TO MILLENNIUM ARE EXCLUSIVE, AND
COLUMBIA EXPRESSLY DISCLAIMS AND NEGATES, AND MILLENNIUM HEREBY WAIVES, ALL
OTHER REPRESENTATIONS AND WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, WITH
RESPECT TO ANY ITEMS OF EQUIPMENT, IMPROVEMENTS, FIXTURES AND APPURTENANCES
ASSIGNED, TRANSFERRED AND


                                        5
<PAGE>   8
CONVEYED AS PART OF THE ASSETS WHICH ARE ASSIGNED, TRANSFERRED AND CONVEYED, AND
MILLENNIUM ACCEPTS SUCH ITEMS "AS IS, WHERE IS, WITH ALL FAULTS" AND THERE ARE
NO WARRANTIES THAT EXTEND BEYOND THE FACE OF THIS AGREEMENT. MILLENNIUM FURTHER
ACKNOWLEDGES THAT THIS WAIVER IS CONSPICUOUS.

                                  ARTICLE VI.
                             ENVIRONMENTAL MATTERS

      6.1 Columbia shall have the following environmental obligations with
respect to the Assets:

            (a)   Columbia is obligated by the AOC to conduct an Environmental
                  Assessment and, if appropriate, to prepare a Response Action
                  Completion Final Report to address environmental conditions at
                  WSL locations, and Columbia and Millennium agree that such
                  work shall be at Columbia's cost and expense. Columbia's
                  obligations and liabilities under the AOC and this Agreement
                  in regard to the Assets which are at WSL locations shall
                  continue until such Environmental Assessment, as evidenced by
                  an Assessment Report, and, if necessary, a Response Action
                  Completion Final Report, are approved by EPA or until such
                  locations are removed from the WSL by EPA.

            (b)   Columbia shall conduct an Environmental Assessment of the
                  Assets as required by the AOC, the results of which shall be
                  set forth in an Assessment Report. Columbia shall furnish
                  Millennium with a copy of any such Assessment Report upon its
                  approval by EPA. Columbia shall obtain approval of the
                  Response Action Work Plan from EPA and shall furnish evidence
                  of that approval to Millennium. Following the completion of
                  the Response Actions required by EPA, Columbia shall furnish
                  Millennium a copy of the Response Action Completion Final
                  Report approved by EPA, including evidence of such approval.
                  Such approvals by EPA shall be binding on Millennium. Columbia
                  shall be responsible for and shall indemnify and hold
                  Millennium, its partners, employees, officers, agents,
                  representatives and, if applicable, their respective
                  shareholders, harmless from and against any and all losses,
                  liabilities, claims, demands, suits, judgments, fines,
                  penalties and costs of any kind or character with respect to
                  all environmental conditions related to the Assets to the
                  extent that the environmental conditions arose out of
                  Columbia's ownership, control or operation of the Assets prior
                  to the Effective Time.

            (c)   Millennium shall be responsible for and indemnify and hold
                  Columbia, its directors, employees, officers, agents,
                  representatives and shareholders harmless from and against any
                  and all losses, liabilities, claims, demands, suits,
                  judgments, fines, penalties and costs of any kind or character
                  with respect to all environmental conditions related to the
                  Assets: (i) caused by the


                                        6
<PAGE>   9
                  actions or omissions of Millennium or a third party after the
                  Effective Time, including subsequent transferees, whether or
                  not such conditions are located at WSL locations and (ii) to
                  the extent any environmental conditions arise after the
                  Effective Time. The scope of this indemnification shall
                  include, but not be limited to, claims by any governmental or
                  other third party for damages, study or cleanup of the Assets
                  beyond that required under the AOC, and statutory or common
                  law claims of third parties for bodily injury or property
                  damage based on or relating to environmental conditions at or
                  emanating from the Assets.

      6.2 Columbia represents that it has furnished Millennium with true and
correct copies of the AOC, the WSL and the COWP. Columbia, as soon as
practicable following EPA approval, shall provide Millennium a copy of any
changes to the AOC, WSL and COWP. Millennium hereby (a) acknowledges receipt of
said copies of the AOC, the WSL and the COWP and (b) accepts and acknowledges
that the Assets are subject to regulation under environmental laws of the states
in which they are located and of the United States of America.

      6.3 Millennium agrees (a) not to alter the Assets or to take any action
with regard to the Assets that would impede Columbia's compliance with the AOC
or COWP, and (b) that Millennium's activities and operations of the Assets will
be conducted in compliance with the AOC and the COWP.

      6.4 After the Effective Time, for the period required by Columbia to
discharge its obligations under this Article VI, upon reasonable notice,
Millennium shall provide Columbia, EPA, their employees, agents, representatives
and contractors, the right to enter onto and have access to the Assets in
accordance with Section 12 of the AOC. In providing such access, Millennium
shall not interfere with, delay or prohibit Columbia's compliance with or EPA's
exercise of authority under the AOC. Millennium shall cooperate with Columbia
and use all commercially reasonable means to provide Columbia and EPA access to
the Assets as promptly as possible upon notice.

      6.5 Millennium shall notify Columbia of proposed earth-disturbing
activities as defined in the COWP with respect to Assets which are at WSL
locations at a time and in a manner to be agreed upon by Columbia and
Millennium. Upon such notification, Columbia shall use reasonable efforts to
perform the necessary Environmental Assessment and, if necessary, to obtain a
Response Action Completion Final Report to address any environmental conditions
in accordance with the AOC and COWP prior to Millennium's proposed
earth-disturbing activities.

      6.6 Millennium shall notify Columbia at the earliest possible time of its
intent to transfer ownership or to delegate material or substantial operation of
Assets which are at WSL locations and for which Columbia has not performed an
Environmental Assessment and, if necessary, received a Response Action
Completion Final Report. Upon such notification, Columbia shall use reasonable
efforts to perform Environmental Assessments and remediation, if necessary,
prior to such transfer of ownership or operation by Millennium of such Assets.
Millennium agrees it shall not transfer ownership or delegate material or
substantial operation of Assets which are WSL locations until such time as
Columbia has received EPA approval of an Environmental Assessment and, if
necessary, a


                                        7
<PAGE>   10
Response Action Completion Final Report or until such locations are removed from
the WSL. In the event of any such delegation or transfer, Millennium shall
ensure that, as a condition to such transfer or delegation, the transferee or
party to whom the operation of the Assets has been delegated shall agree to be
bound by the obligations of Millennium under this Article VI. Notwithstanding
the preceding sentence, nothing contained herein shall relieve Millennium from
such obligations.

      6.7 In the event of a situation occurring at Assets which are at WSL
locations where immediate action is required for the protection of life, health
or maintenance of physical property, and earth disturbance as defined in the AOC
is required to remedy the situation, Millennium shall perform the
earth-disturbing activity in accordance with the AOC and the emergency
procedures specified in the COWP. Millennium shall immediately notify Columbia
of any such situation and shall cooperate with Columbia in regard to such
actions necessary to ensure compliance with the AOC and COWP.

      6.8 If Columbia, its employees, agents, representatives or contractors
enter upon Millennium's property in order to identify or address any obligations
imposed upon Columbia by this Article VI, Millennium shall indemnify Columbia
and hold Columbia harmless from any and all claims and liabilities resulting
from such claims, asserted by Millennium's employees, representatives,
contractors or agents arising from the presence of Columbia or its employees,
representatives, contractors or agents on the subject property to identify or
address any obligations imposed on Columbia by this Article VI, so long as such
claims do not arise from the gross negligence or willful misconduct of Columbia
and/or Columbia's employees, agents, representatives or contractors.

      6.9 Columbia reserves the right to negotiate such modifications,
amendments or supplements to the AOC, COWP and WSL as it in its sole discretion
deems necessary or advisable; provided, however, that Columbia shall not modify,
amend or supplement the AOC, COWP or WSL without consulting with Millennium if
such modifications, amendments or supplements could reasonably be expected to
have an adverse impact on Millennium or the Millennium Pipeline System. Nothing
in this Agreement shall be construed to impose a separate, contractual
obligation on the part of Columbia to take any action with respect to the Assets
that is not required by the AOC, COWP or WSL. With respect to Assets for which a
Response Action Completion Final Report has been received or which has been
removed from the WSL, nothing in this Agreement shall be construed to impose an
obligation upon Columbia to perform any work to comply with new or more
stringent environmental standards or requirements as may be incorporated into a
subsequent amendment or supplement to the AOC, COWP or WSL.

                                  ARTICLE VII.
                         REPRESENTATIONS AND WARRANTIES

      7.1 As of the Transfer Date, Columbia represents and warrants to
Millennium as follows:

            (a)   Columbia is a duly organized, validly existing corporation in
                  good standing under the laws of the State of Delaware, with
                  full corporate power and authority to engage in the business
                  in which it is now engaged.


                                        8
<PAGE>   11
            (b)   Columbia has the corporate authority to execute, deliver and
                  perform this Agreement. The execution, delivery and
                  performance of this Agreement by Columbia has been duly
                  authorized by all necessary corporate action and no additional
                  corporate or FERC approvals or authorizations are required in
                  connection with Columbia's execution, delivery and performance
                  of this Agreement. Neither the execution and delivery of this
                  Agreement nor the consummation of the transactions herein
                  contemplated will violate the articles of incorporation or
                  other governing documents of Columbia or will result in any
                  breach or default under any agreement or other instrument to
                  which Columbia is a party;

            (c)   Neither the execution and delivery of this Agreement nor
                  (assuming receipt of a Final Order approving the Abandonment
                  Application) the consummation of the transactions contemplated
                  by this Agreement will violate any statute or regulation
                  applicable to Columbia in any material respect, or any order
                  or decree of any court or governmental authority applicable to
                  Columbia;

            (d)   Other than as provided for in Schedule I attached hereto and
                  made a part hereof, as supplemented on the Transfer Date,
                  Columbia (i) has no actual knowledge of any actions, suits or
                  administrative proceedings or investigations pending or
                  threatened against Columbia that relate in any respect to the
                  Assets and is not in default with respect to any order,
                  injunction or decree of any court or governmental department,
                  commission, board or agency relating to the Assets; (ii) has
                  no actual knowledge of any outstanding claims or demands
                  relating to damage to property arising out of Columbia's
                  ownership, operation or maintenance of the Assets; and (iii)
                  has no actual knowledge of and has not received any notice
                  from any governmental body or official thereof of any material
                  violation of any law, order or regulation relating to the
                  ownership, maintenance and operation of the Assets;

            (e)   The Assets are owned by Columbia and are being assigned,
                  transferred and conveyed to Millennium free and clear of all
                  claims, mortgages, liens and encumbrances arising by, through
                  or under Columbia, but not further;

            (f)   That portion of the Assets consisting of tangible property has
                  been maintained in good repair and working condition, subject
                  to reasonable wear and tear;

            (g)   The financial statements used to determine the Net Book Value
                  are complete, true and correct in all material respects;

            (h)   That there have not been, except as may have been disclosed to
                  Millennium, any material adverse changes in the condition of
                  Assets between the effective date of this Agreement and the
                  Transfer Date; and


                                        9
<PAGE>   12
            (i)   Columbia has not made any regulatory applications, other than
                  the Abandonment Application, relating to the Assets.

      7.2 As of the Transfer Date, Millennium represents and warrants to
Columbia as follows:

            (a)   Millennium is a duly organized, validly existing limited
                  partnership in good standing under the laws of the State of
                  Delaware, with full partnership power and authority to engage
                  in the business in which it is now engaged.

            (b)   Millennium has the partnership authority to execute, deliver
                  and perform this Agreement. The execution, delivery and
                  performance of this Agreement by Millennium has been duly
                  authorized by all necessary partnership action and no
                  additional partnership or FERC approvals or authorizations are
                  required in connection with Millennium's execution, delivery
                  and performance of this Agreement. Neither the execution and
                  delivery of this Agreement nor the consummation of the
                  transactions herein contemplated will violate the LP Agreement
                  or other governing documents of Millennium or will result in
                  any breach or default under any agreement or other instrument
                  to which Millennium is a party.

            (c)   There are no pending or threatened legal actions or suits with
                  respect to Millennium or its properties and assets which in
                  any way affect consummation of the transactions contemplated
                  hereby and Millennium is not subject to any judgment, order,
                  decree, seizure or lien which would adversely affect the
                  transactions contemplated hereby.

            (d)   Except for the Abandonment Application, Millennium has
                  obtained or will be solely responsible for obtaining any
                  permits, licenses or consents required by any governmental
                  authority or other entity in connection with the use and
                  occupancy of the Assets, whether necessary due to the
                  non-transferability of any permit, license or consent
                  comprising the Assets or for any other reason.

            (e)   Neither the execution and delivery of this Agreement, nor the
                  consummation of the transactions herein contemplated, will
                  violate any statute or regulation applicable to Millennium, or
                  any order or decree of any court or governmental authority
                  applicable to Millennium.

                                 ARTICLE VIII.
                                INDEMNIFICATION

      8.1 Millennium shall indemnify, defend and hold Columbia, its employees,
directors, officers, agents and its shareholders harmless from and against any
and all losses, liabilities, claims, demands, suits, judgments, fines, penalties
and costs of any kind or character, whether groundless or not, (a) that accrue
or relate to any period of time after the Effective Time with respect to the
Assets, (b) that arise from Millennium's failure to comply with Millennium's
obligations as set forth


                                       10
<PAGE>   13
herein in Article VI hereof or (c) that result from any material breach by
Millennium of any representations, warranties, covenants or agreements which
survive the assignment, transfer and conveyance of the Assets to Millennium
pursuant to this Agreement. If a claim involves a claim by a third party against
Columbia for which Millennium has an indemnification obligation, Millennium may,
at its sole discretion and expense, assume the defense of such claim.

      8.2 Columbia shall indemnify, defend, and hold Millennium, its partners,
employees, officers, agents, representatives, and, if applicable, their
respective shareholders, harmless from and against any and all losses,
liabilities, claims, demands, suits, judgments, fines, penalties and costs of
any kind or character, whether groundless or not, (a) that accrue or relate to
any period of time prior to the Effective Time, (b) that arise from Columbia's
failure to comply with Columbia's obligations as set forth in Article VI hereof
or (c) that result from any material breach by Columbia of any representations,
warranties, covenants or agreements which survive the assignment, transfer and
conveyance of the Assets to Millennium pursuant to this Agreement. If a claim
involves a claim by a third party against Millennium for which Columbia has an
indemnification obligation, Columbia may, at its sole discretion and expense,
assume the defense of such claim. Columbia's obligations under this Section 8.2
shall terminate on the date that is two (2) years after the Effective Time,
except with respect to its obligations relating to matters arising under Article
VI hereof, if any, which shall terminate in accordance with the terms of that
section, and provided that Columbia's obligations, if any, under this Section
8.2 shall continue after the expiration of such two (2) year period with respect
to claims that were asserted during such two (2) year period and as to which
Millennium made a proper claim for indemnification by Columbia under this
Section 8.2 during such two (2) year period.

      8.3 The provisions of this Article VIII shall survive the Transfer Date.

      8.4 Nothing contained in this Article VIII is intended to limit the
indemnification obligations of the Parties pursuant to Section 6.1(b) and (c)
hereof which shall survive indefinitely.

                                  ARTICLE IX.
                     CONDITIONS PRECEDENT AND TERMINATION

      9.1 All obligations of Columbia under this Agreement are subject to
fulfillment of each of the following conditions precedent:

            (a)   All of the representations and warranties made by Millennium
                  under Section 7.2 hereof shall be true and correct as of the
                  Transfer Date;

            (b)   Millennium shall have performed and complied in all material
                  respects with all agreements, provisions and conditions
                  required by this Agreement to be performed or complied with by
                  Millennium prior to or at the Transfer Date;

            (c) The Certificate Approval shall have occurred;


                                       11
<PAGE>   14
            (d)   Prior to or on the Transfer Date, Columbia shall have: (i)
                  received a Final Order approving the Abandonment Application
                  on terms which are not materially different than those set
                  forth in the Abandonment Application and (ii) received all
                  other necessary regulatory approvals that are required in
                  order for Columbia to consummate the transactions contemplated
                  by this Agreement; and

            (e)   Subject to Section 9.3 hereof, there shall be no bona fide
                  suit, action or other proceeding or investigation before any
                  court or before any governmental agency or submission by any
                  governmental agency of information relating to the subject
                  matter of the transactions contemplated by this Agreement nor
                  any other bona fide material claim or demand pending in which
                  the consummation of this Agreement or the transactions
                  contemplated hereby may be restrained, prohibited,
                  invalidated, set aside or delayed in whole or in part.

      9.2 All obligations of Millennium under this Agreement are subject to
fulfillment of each of the following conditions precedent:

            (a)   All of the representations and warranties made by Columbia
                  under Section 7.1 hereof shall be true and correct as of the
                  Transfer Date;

            (b)   Columbia shall have performed and complied in all material
                  respects with all agreements, provisions and conditions
                  required by this Agreement to be performed or complied with by
                  Columbia prior to or on the Transfer Date;

            (c)   Prior to or on the Transfer Date, Columbia shall have received
                  (i) a Final Order approving the Abandonment Application and
                  (ii) all other necessary regulatory approvals that are
                  required in order for Columbia to consummate the transactions
                  contemplated by this Agreement;

            (d)   Prior to or on the Transfer Date, Columbia shall have obtained
                  a release of the Assets from Columbia's Wilmington Trust
                  Company mortgage;

            (e)   If necessary, Columbia shall have notified the EPA of the
                  transfer contemplated herein thirty (30) days prior to the
                  Transfer Date;

            (f)   There shall be no bona fide suit, action or other proceeding
                  or investigation before any court or governmental agency nor
                  any other bona fide material claim or demand, pending in which
                  the consummation of this Agreement or the transactions
                  contemplated hereby may be restrained, prohibited,
                  invalidated, set aside or delayed in whole or in part;

            (g)   Millennium has obtained satisfactory financing for the
                  construction of the Millennium Pipeline System; and


                                       12
<PAGE>   15
            (h)   Millennium has constructed all or substantially all of the
                  Millennium Pipeline System.

      9.3 Notwithstanding the provisions of Section 9.1(e) above, the resolution
of proceedings before the United States Court of Appeals with respect to one or
more petitions for review of a Final Order granting the Certificate Approval and
approving the Abandonment Application shall not constitute a condition precedent
of Columbia's obligations under this Agreement if Millennium (a) notifies
Columbia that all of the conditions precedent set forth in Section 9.2 hereof
have been satisfied or waived, (b) indemnifies and holds Columbia, its
directors, employees, officers, agents, representatives and shareholders
harmless from and against any and all losses, claims, demands, suits, judgments,
fines, penalties and costs of any kind or character arising from or relating to
the fact that Columbia transferred, conveyed and assigned the Assets to
Millennium while any such suit, action or proceeding was pending and (c)
provides Columbia with a guaranty or guarantees of the indemnification
obligations of Millennium pursuant to this Section 9.3 or other form of credit
support from an entity or entities with a rating of BBB or better by Standard &
Poor's (or an equivalent rating by another rating agency) acceptable to
Columbia.

      9.4 This Agreement may be terminated on the following terms and
conditions:

            (a)   By mutual agreement of the Parties;

            (b)   By either Party if the conditions set forth in Sections 9.1
                  and 9.2 hereof are not met or waived by December 31, 2000;

            (c)   By Millennium if Millennium elects not to proceed with the
                  construction of the proposed project; and

            (d)   By Columbia if Columbia receives a notice from Millennium that
                  Millennium has elected not to proceed with the construction of
                  the proposed project.

                                  ARTICLE X.
                                 TRANSFER DATE

      10.1 The assignment, transfer and conveyance of the Assets shall take
place on a date which is not more than ten (10) days after date on which
Millennium places the Millennium Pipeline System in service and shall take place
at a time and place to be mutually agreed upon between the Parties (the
"Transfer Date").

      10.2 On the Transfer Date the following events shall occur, each being a
condition precedent to the others and each being deemed to have occurred
simultaneously with the others:

            (a)   Columbia shall execute, acknowledge and deliver to Millennium
                  assignment, transfer and conveyance documents and such other
                  instruments as may be


                                       13
<PAGE>   16
                  necessary to assign, transfer and convey to Millennium the
                  Assets in the manner contemplated by this Agreement;

            (b)   Columbia shall deliver to Millennium possession of the Assets
                  and Millennium shall take possession of the Assets as of the
                  Effective Time; and

            (c)   Columbia and Millennium shall prepare a preliminary settlement
                  statement showing all known costs and expenses owed or due at
                  the Transfer Date, subject to the preparation of a final
                  settlement statement to be prepared in accordance with Section
                  11.2 hereof.

                                  ARTICLE XI.
                      OBLIGATIONS AFTER THE TRANSFER DATE

      11.1 Except for the Abandonment Application and as otherwise provided in
this Agreement, Millennium shall obtain any permits, licenses or consents
required by any governmental authority or other entity in connection with the
use and occupancy of the Assets, whether necessary due to the
non-transferability of any such permit, license or consent, or for any other
reason. The obtaining of any such permits, licenses or consents shall be the
sole responsibility and liability of Millennium.

      11.2 Within one hundred eighty (180) days after the Transfer Date, a final
settlement statement shall be prepared by Millennium and shall be agreed upon by
Millennium and Columbia.

      11.3 If the assignment, transfer and conveyance of the Assets occurs,
Millennium and Columbia shall be deemed to have waived, to the fullest extent
permitted under applicable law, any right to contribution, set-off or recoupment
against each other and any and all rights, claims and causes of action they may
have against each other arising under or based on any federal, state or local
statute, law, ordinance, rule or regulation or common law or otherwise;
provided, however, that nothing contained herein shall be deemed to constitute a
waiver of any rights, claims or causes of action that either Party may have
against the other Party for a breach of any of the covenants to be performed by
such other Party at any time after the Effective Time or any other provisions of
this Agreement that survive the Transfer Date in accordance with Article VIII
hereof.

      11.4 If the assignment, transfer and conveyance of the Assets occurs, the
sole and exclusive remedy of the Parties with respect to any claim arising out
of the assignment, transfer and conveyance of the Assets shall be pursuant to
the express provisions of this Agreement. Columbia and Millennium acknowledge
that the payment of money, as limited by the terms of this Agreement, shall be
adequate compensation for breach of any covenant or agreement contained herein
or for any other claim arising in connection with or with respect to the
transactions contemplated in this Agreement. As the payment of money shall be
adequate compensation, Millennium and Columbia waive any right to rescind this
Agreement or any of the transactions contemplated hereby. The Parties
acknowledge that prior to the Transfer Date there will be no adequate remedy at
law for Millennium for a breach of the covenants and agreements of Columbia
contained herein. It is accordingly agreed that, in addition to any other
remedies that may be available to Millennium upon


                                      14
<PAGE>   17
the breach by Columbia of such covenants and agreements, Millennium shall have
the right to obtain injunctive relief to restrain any breach or threatened
breach of the covenants or agreements or to otherwise obtain specific
performance of any such covenants and agreements.

                                 ARTICLE XII.
                                 DOCUMENTATION

      12.1 Prior to or on the Transfer Date, Columbia, at Millennium's request
and expense, shall furnish or make available for inspection and copying to
Millennium, its affiliates, partners and their representatives, the following
materials:

            (a)   Copies of all deeds, leases, easements, rights-of-way,
                  licenses, permits and other grants of rights or authority
                  utilized by Columbia in connection with the construction,
                  operation, repair and maintenance of the Assets;

            (b)   Copies of all maps and construction, design, engineering and
                  other data pertinent to the construction, operation, repair
                  and maintenance of the Assets. Such information shall include
                  any U.S. Department of Transportation, Office of Pipeline
                  Safety records and reports, all available records relating to
                  materials, supplies and maintenance work performed and all
                  reports relating to inspection of the Assets;

            (c)   All available records relating to assessment, appraisal, entry
                  and payment of taxes relating to the Assets;

            (d)   All notices, certificates, orders, fines and other
                  communications from any pertinent government regulatory
                  authority relating to construction, maintenance, repair or
                  operation of the Assets and to compliance with applicable law
                  or regulations; and

            (e)   All notices, claims or demands from any person, legal entity,
                  government authority or subdivision relating to the validity
                  of any easement, right-of-way, privilege, license or permit of
                  Columbia in connection with the Assets.

                                 ARTICLE XIII.
                           MISCELLANEOUS PROVISIONS

      13.1 It is the intent of Millennium to acquire and of Columbia to assign,
transfer and convey all of Columbia's interest in the Assets except as provided
in Article II hereof. In the event that any interest owned by Columbia in the
Assets are omitted or incorrectly described herein, the Parties agree to execute
the documents necessary to effect the intent stated herein.

      13.2 Except to the extent otherwise provided herein, each Party hereto
shall pay its own expenses incidental to the preparation of this Agreement, the
carrying out of the provisions of this Agreement and the consummation of the
transactions contemplated hereby.


                                       15
<PAGE>   18
      13.3 Each Party shall cooperate with the other Party in its efforts to
obtain any regulatory authorization necessary to consummate the transactions
contemplated under this Agreement.

      13.4 All notices, requests, demands, consents, waivers or other
communications hereunder shall be in writing and shall be deemed given when
delivered personally or upon receipt by the addressee if deposited in the United
States first-class mail or United States registered or certified mail, return
receipt requested, postage prepaid, as follows:

            If to Millennium to:

                  Millennium Pipeline Company, L.P.
                  c/o Millennium Pipeline Management Company, L.L.C.,
                        General Partner
                  12801 Fair Lakes Parkway
                  P. O. Box 10146
                  Fairfax, VA  22030-0146
                  Attn: Mr. David C. Pentzien
                  Telephone:  (703) 337-3200
                  Telecopy:   (703) 227-3225


            If to Columbia, to:

                  Columbia Gas Transmission Corporation
                  12801 Fair Lakes Parkway
                  Fairfax, VA  22030
                  Telephone:  (703) 227-3200
                  Telecopy:   (703) 227-3225

or to such other address or party at that address as may be designated by prior
written notice by the Party entitled to receive such written notice.

      13.5 All section headings are for convenience only and shall in no way
modify or restrict any of the provisions thereof.

      13.6 This Agreement shall be governed by and interpreted in accordance
with the laws of the State of New York (without reference to its conflict of
laws provisions).

      13.7 This Agreement shall be binding upon and inure to the benefit of and
be enforceable by the respective successors by law of the Parties; provided,
however, that no assignment shall be made without prior written consent of the
other Party which consent shall not be unreasonably withheld. This Agreement may
not be amended or terminated except by written instrument signed by the Parties
or as provided herein.


                                       16
<PAGE>   19
      13.8 This Agreement was drafted by the joint effort of the Parties and
neither Party shall be deemed to have predominated in or controlled the
drafting.

      13.9 Nothing in this Agreement shall entitle any person other than the
Parties or their respective successors and assigns permitted hereby to any
claim, cause of action, remedy or right of any kind. There are no intended
third-party beneficiaries to this Agreement.

      13.10 This Agreement and the exhibits and schedules hereto collectively
constitute the entire agreement between the Parties pertaining to the subject
matter hereof and supersede all prior agreements, understandings, negotiations
and discussions, whether oral or written, of the Parties relating to the subject
matter hereof except as specifically set forth in this Agreement, and neither of
the Parties shall be bound by or liable for any alleged representation, promise,
inducement or statements of intention not so set forth.

      13.11 This Agreement may be executed in several counterparts, each of
which shall be an original. This Agreement and any counterparts so executed
shall be deemed to be one and the same instrument. It shall not be necessary in
making proof of this Agreement or any counterpart hereof to produce or account
for any of the other counterparts.

      13.12 If any section or provision of this Agreement shall be held by any
court of competent jurisdiction to be illegal, void or unenforceable, such
section or provision shall survive to the extent enforceable as allowed by law,
but the illegality or unenforceability of any such section or provision shall
have no effect upon and shall not impair the enforceability of any other section
or provision of this Agreement.

      13.13 The obligations of Columbia under this Agreement shall remain in
full force and effect if Columbia becomes a "Withdrawing Limited Partner" as
that term is defined in the LP Agreement.





               [THE REMAINDER OF THIS PAGE INTENTIONALLY BLANK]


                                       17
<PAGE>   20
      IN WITNESS WHEREOF, Columbia and Millennium have caused this Agreement to
be executed as of July 31, 1998.

                             COLUMBIA GAS TRANSMISSION
                             CORPORATION

                             By:_________________________________________
                             Printed Name: ______________________________
                             Title: _____________________________________



                             MILLENNIUM PIPELINE COMPANY, L.P.,
                             a Delaware limited partnership

                             By:   Millennium Pipeline Management Company,
                                   L.L.C., a Delaware limited liability company,
                                   its General Partner


                             By: ________________________________________
                                 David C. Pentzien, Chairman




                                SIGNATURE PAGE TO
                             CONTRIBUTION AGREEMENT




                                       18
<PAGE>   21
                       SCHEDULE I - ACTIONS, SUITS, ETC.


1.    AOC
2.    Mortgage in favor of Wilmington Trust Company




<PAGE>   1
                                                                   Exhibit 10-CI

                                   REGULATIONS

                                       OF

                 MILLENNIUM PIPELINE MANAGEMENT COMPANY, L.L.C.

                      A DELAWARE LIMITED LIABILITY COMPANY
<PAGE>   2
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                 PAGE NO.
                                                                                 --------
<S>                                                                              <C>
                                  ARTICLE 1.
                                  DEFINITIONS
1.01  Definitions............................................................       2
      (a)   "AAA"............................................................       2
      (b)   "Abstaining Member"..............................................       2
      (c)   "Act"............................................................       2
      (d)   "Action".........................................................       2
      (e)   "Additional Capital Contributions"...............................       2
      (f)   "Adjusted Capital Account Deficit"...............................       2
      (g)   "Affiliate"......................................................       2
      (h)   "Affiliate Transaction"..........................................       3
      (i)   "Allocation Year"................................................       3
      (j)   "Available Cash".................................................       3
      (k)   "Bankrupt Member"................................................       3
      (l)   "Bankruptcy".....................................................       3
      (m)   "Base Interest Rate".............................................       4
      (n)   "Budget".........................................................       4
      (o)   "Business Day"...................................................       4
      (p)   "Capacity Lease and Exchange Agreement"..........................       4
      (q)   "Capital Account"................................................       4
      (r)   "Capital Contributions"..........................................       5
      (s)   "Certificate" or "Certificate of Formation"......................       5
      (t)   "Certificate of Dissolution".....................................       5
      (u)   "Change in Control"..............................................       5
      (v)   "Code"...........................................................       6
      (w)   "Columbia".......................................................       6
      (x)   "Commitment Voting Date".........................................       6
      (y)   "Company"........................................................       6
      (z)   "Contribution Agreement".........................................       6
      (aa)  "Contribution Date"..............................................       6
      (bb)  "Credit Support Documents".......................................       6
      (cc)  "Debt"...........................................................       6
      (dd)  "Delinquent Member"..............................................       7
      (ee)  "Depreciation"...................................................       7
      (ff)  "DGCL"...........................................................       7
      (gg)  "Dispose," "Disposing" or "Disposition"..........................       7
      (hh)  "Dispute"........................................................       7
      (ii)  "Dissolution Event"..............................................       7
</TABLE>


                                        i
<PAGE>   3
<TABLE>
<S>                                                                              <C>
      (jj)  "Effective Date"................................................       7
      (kk)  "Encumbrance"...................................................       7
      (ll)  "Excess Withholding Liability"..................................       7
      (mm)  "FERC"..........................................................       8
      (nn)  "General Interest Rate".........................................       8
      (oo)  "Gross Asset Value".............................................       8
      (pp)  "Information Request"...........................................       9
      (qq)  "Initial Capital Contributions".................................       9
      (rr)  "In-Service Date"...............................................       9
      (ss)  "Interested Matters Voting Procedures"..........................       9
      (tt)  "Lake Crossing Agreement".......................................       9
      (uu)  "Limited Partner"...............................................       9
      (vv)  "Losses"........................................................       9
      (ww)  "Majority Approval".............................................       9
      (xx)  "Management Committee"..........................................       9
      (yy)  "Market Value"..................................................       9
      (zz)  "MCN"...........................................................       9
      (aaa) "Member Agreement"..............................................       9
      (bbb) "Member Nonrecourse Debt".......................................       10
      (ccc) "Member Nonrecourse Debt Minimum Gain"..........................       10
      (ddd) "Member Nonrecourse Deductions".................................       10
      (eee) "Member Owner"..................................................       10
      (fff) "Members".......................................................       10
      (ggg) "Membership Interest"...........................................       10
      (hhh) "Millennium Pipeline System"....................................       10
      (iii) "Millennium Pipeline Company, L.P.".............................       10
      (jjj) "MOU"...........................................................       11
      (kkk) "Net Cash Flow".................................................       11
      (lll) "Nonrecourse Deductions"........................................       11
      (mmm) "Nonrecourse Liability".........................................       11
      (nnn) "Notice Period".................................................       11
      (ooo) "Offeree Member"................................................       11
      (ppp) "O&M Agreement".................................................       11
      (qqq) "Partnership"...................................................       11
      (rrr) "Partnership Agreement".........................................       11
      (sss) "Person"........................................................       11
      (ttt) "Precedent Agreements"..........................................       11
      (uuu) "Prime Rate"....................................................       11
      (vvv) "Profits" and "Losses"..........................................       11
      (www) "Project Agreements"............................................       13
      (xxx) "Project Development Agreement".................................       13
      (yyy) "Property"......................................................       13
      (zzz) "PUHCA".........................................................       13
</TABLE>


                                       ii
<PAGE>   4
<TABLE>
<S>                                                                              <C>
      (aaaa)"PUHCA Company".................................................       13
      (bbbb)"Reconstitution Period".........................................       13
      (cccc)"Regulations"...................................................       13
      (dddd)"Regulatory Allocations"........................................       13
      (eeee)"Required Accounting Practices".................................       13
      (ffff)"Required Interest".............................................       13
      (gggg)"Sale Notice"...................................................       13
      (hhhh)"Scheduled Capital Contributions"...............................       13
      (iiii)"Super Majority Approval".......................................       14
      (jjjj)"System Modification"...........................................       14
      (kkkk)"Third Party Terms".............................................       14
      (llll)"TransCanada"...................................................       14
      (mmmm)"Treasury Regulations"..........................................       14
      (nnnn)"UCC"...........................................................       14
      (oooo) "Unanimous Approval"...........................................       14
      (pppp)"Westcoast".....................................................       14
      (qqqq)"Withdrawal Effective Date" ....................................       14
      (rrrr)"Withdrawal Notice".............................................       14
      (ssss)"Withdrawal Period".............................................       14
      (tttt)"Withdrawing Member"............................................       15

1.02  Construction..........................................................       15

                                  ARTICLE 2.
                                 ORGANIZATION

2.01  Formation.............................................................       15
2.02  Name..................................................................       15
2.03  Registered Office; Registered Agent; Principal Office in the United
           States; Other Offices............................................       15
2.04  Purposes..............................................................       15
2.05  Foreign Qualification.................................................       16
2.06  Term..................................................................       16
2.07  Mergers and Exchanges.................................................       16
2.08  Tax Partnership; No State-Law Partnership.............................       16

                                  ARTICLE 3.
                     MEMBERSHIP; DISPOSITIONS OF INTERESTS

3.01  Initial Members.......................................................       16
3.02  Membership............................................................       16
3.03  Representations and Warranties........................................       17
      (a)   In General......................................................       17
      (b)   Representations and Warranties..................................       17
</TABLE>

                                       iii
<PAGE>   5
<TABLE>
<S>                                                                             <C>
3.04  Restrictions on the Disposition of Membership Interests...............       19
3.05  Additional Members....................................................       20
3.06  Membership Interests..................................................       20
3.07  Rights of First Refusal...............................................       20
3.08  Restrictions Applicable Upon Disposition..............................       21
3.09  PUHCA.................................................................       21
3.10  Remedies..............................................................       21
3.11  Information; Confidentiality..........................................       22
3.12  Legends...............................................................       22
3.13  Liability to Third Parties............................................       22
3.14  Withdrawal and Effect of Withdrawal...................................       22
3.15  Lack of Authority.....................................................       25

                                  ARTICLE 4.
                             CAPITAL CONTRIBUTIONS

4.01  Initial and Scheduled Capital Contributions...........................       25
4.02  Additional Capital Contributions......................................       25
4.03  Failure to Contribute.................................................       25
4.04  Return of Contributions...............................................       26
4.05  Advances by Members...................................................       26
4.06  Capital Account.......................................................       26
4.07  Capital Contributions for System Modifications........................       26

                                  ARTICLE 5.
                                  ALLOCATIONS

5.01  Profits...............................................................       26
5.02  Losses................................................................       27
5.03  Special Federal Income Tax Allocations................................       27
      (a)   Minimum Gain Chargeback.........................................       27
      (b)   Member Minimum Gain Chargeback..................................       27
      (c)   Qualified Income Offset.........................................       28
      (d)   Nonrecourse Deductions..........................................       28
      (e)   Member Nonrecourse Deductions...................................       28
      (f)   Section 754 Adjustments.........................................       28
5.04  Curative Allocations..................................................       28
5.05  Loss Limitation.......................................................       29
5.06  Other Allocation Rules................................................       29
5.07  Contributed Property, Tax Allocations.................................       29
</TABLE>


                                       iv
<PAGE>   6
<TABLE>
<S>                                                                             <C>
                                  ARTICLE 6.
                                 DISTRIBUTIONS

6.01  Distributions.........................................................       30
6.02  Tax Amounts Withheld..................................................       30
6.03  Limitations on Distributions..........................................       30

                                  ARTICLE 7.
                           MANAGEMENT OF THE COMPANY

7.01  Management by the Members.............................................       31
7.02  Actions by Member Committees; Delegation of Authority and Duties......       31
7.03  Conflicts of Interest and Affiliate Transactions......................       32
7.04  Officers..............................................................       33
      (a)   Qualifications, Duties and Term of Office.......................       33
      (b)   Resignation; Removal............................................       34
      (c)   Officers........................................................       34
      (d)   Initial Officers................................................       36
7.05  Insurance.............................................................       36

                                  ARTICLE 8.
                              MEETINGS OF MEMBERS

8.01  Meetings..............................................................       36
8.02  Voting List...........................................................       38
8.03  Proxies...............................................................       38
8.04  Conduct of Meetings...................................................       38
8.05  Action by Written Consent or Telephone Conference.....................       39

                                  ARTICLE 9.
                                INDEMNIFICATION

9.01  Right to Indemnification..............................................       39
9.02  Advance Payment.......................................................       40
9.03  Indemnification of Officers, Employees and Agents.....................       40
9.04  Appearance of Witness.................................................       40
9.05  Nonexclusivity of Rights..............................................       41
9.06  Insurance.............................................................       41
9.07  Member Notification...................................................       41
9.08  Saving Clause.........................................................       41
</TABLE>


                                        v
<PAGE>   7
<TABLE>
<S>                                                                             <C>
                                  ARTICLE 10.
                                     TAXES

10.01 Tax Returns...........................................................       41
10.02 Tax Elections.........................................................       42
10.03 Tax Matters Partner...................................................       42
10.04 Tax Reporting Information.............................................       43

                                  ARTICLE 11.
                  BOOKS, RECORDS, REPORTS, AND BANK ACCOUNTS

11.01 Maintenance of Books..................................................       43
11.02 Reports...............................................................       43
11.03 Accounts..............................................................       44

                                  ARTICLE 12.
                            BANKRUPTCY OF A MEMBER

12.01 Bankrupt Members......................................................       44

                                  ARTICLE 13.
           DISSOLUTION, LIQUIDATION, TERMINATION AND RECONSTITUTION

13.01 Dissolution...........................................................       44
13.02 Winding Up, Liquidation and Termination...............................       45
13.03 Deficit Capital Accounts..............................................       46
13.04 Certificate of Dissolution............................................       46
13.05 Reconstitution........................................................       46

                                  ARTICLE 14.
                              DISPUTE RESOLUTION

14.01 Disputes..............................................................       47
14.02 Negotiations to Resolve Disputes......................................       47
14.03 Arbitration...........................................................       47

                                  ARTICLE 15.
                              GENERAL PROVISIONS

15.01 Regulations Subordinate to Member Agreement...........................       49
15.02 Compliance with Partnership Agreement.................................       49
15.03 Payments and Offset...................................................       49
15.04 Notices...............................................................       49
</TABLE>


                                       vi
<PAGE>   8
<TABLE>
<S>                                                                             <C>
15.05 Ratification..........................................................       50
15.06 Entire Agreement; Acknowledgment......................................       51
15.07 Effect of Waiver or Consent...........................................       51
15.08 Amendment or Modification.............................................       51
15.09 Binding Effect........................................................       51
15.10 Governing Law.........................................................       52
15.11 Severability..........................................................       52
15.12 Further Assurances....................................................       52
15.13 Waiver of Certain Rights..............................................       52
15.14 Indemnification.......................................................       52
15.15 Notice to Members of Provisions of these Regulations..................       52
15.16 Counterparts..........................................................       52
</TABLE>


<TABLE>
<S>                                                                       <C>
Exhibit A
Initial Members, Membership Interest and Initial Capital Contribution...  A - 1

Exhibit B
Member Owners...........................................................  B - 1

Exhibit C
Initial Management Committee............................................  C - 1

Exhibit D
Initial Officers........................................................  D - 1
</TABLE>

Schedule 7.01(b) - Super Majority Approval
Schedule 7.01(c) - Unanimous Approval
Schedule 7.01(d) - Interested Matters Voting Procedures


                                       vii
<PAGE>   9
                                   REGULATIONS

                                       OF

                 MILLENNIUM PIPELINE MANAGEMENT COMPANY, L.L.C.

                      A Delaware Limited Liability Company

      These REGULATIONS OF MILLENNIUM PIPELINE MANAGEMENT COMPANY, L.L.C. (these
"Regulations"), dated effective as of May 31, 1998, are executed and agreed to
by the Members (as defined below).

                                    PREAMBLE

      The Members have formed the Company (defined below) to serve as the
general partner of Millennium Pipeline Company, L.P. (defined below) which is
being formed to construct and own an interstate natural gas transmission system
(the "Millennium Pipeline System") extending from an interconnection with a
natural gas transmission system to be owned and operated by TransCanada
PipeLines Limited at the border between the United States and Canada in Lake
Erie to a terminus in Westchester County, New York. The Members anticipate that
the Millennium Pipeline System will be project financed and will be in service
by the end of 2000.

      The Members currently own all of the issued and outstanding Membership
Interests (as defined below) in the Company, including, without limitation,
rights to distribution (liquidating or otherwise), allocations, information,
consent and approval. In order to maintain competent management of the Company,
to encourage and promote the business opportunities of the Members and the
Company, to provide for continuity of the present ownership of the Company and
to impose certain restrictions and obligations on the Membership Interests, the
Members desire to execute these Regulations upon the terms and conditions
contained herein.

      For and in consideration of the mutual covenants and agreements
hereinafter contained and for other good and valuable consideration, the full
receipt and sufficiency of which is hereby expressly acknowledged, the Members
agree as follows:

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


MEMBERSHIP INTERESTS IN MILLENNIUM PIPELINE MANAGEMENT COMPANY, L.L.C. HAVE NOT
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE
STATE SECURITIES LAWS AND MAY NOT BE OFFERED FOR SALE, SOLD OR OTHERWISE
TRANSFERRED UNLESS SUBSEQUENTLY REGISTERED UNDER SUCH ACTS OR UNLESS AN
EXEMPTION FROM SUCH REGISTRATION IS AVAILABLE. THIS AGREEMENT CONTAINS
ADDITIONAL RESTRICTIONS ON SALES AND OTHER TRANSFERS OF MEMBERSHIP INTERESTS.
<PAGE>   10
                                  ARTICLE 1.

                                  DEFINITIONS

      1.01 Definitions. As used in these Regulations, the following terms have
the following meanings throughout these Regulations when capitalized:

            (a) "AAA" shall have the meaning set forth in Section 14.03 hereof.

            (b) "Abstaining Member" means a Member that has elected to abstain
from voting on any matter put to a vote of the Members.

            (c) "Act" means the Delaware Limited Liability Company Act, 6 Del.
C. Section 18-101 et seq. and any successor statute, as amended from time to
time.

            (d) "Action" shall have the meaning set forth in Section 9.01 
hereof.

            (e) "Additional Capital Contributions" means an amount of cash which
a Member is committed to contribute to the Company pursuant to Section 4.02
hereof.

            (f) "Adjusted Capital Account Deficit" means, with respect to any
Member, the deficit balance, if any, in such Member's Capital Account as of the
end of the relevant Allocation Year, after giving effect to the following
adjustments:

                  (i) Credit to such Capital Account any amounts which such
      Member is deemed to be obligated to restore pursuant to the penultimate
      sentences in Sections 1.704-2(g)(1) and 1.704-2(i)(5) of the Treasury
      Regulations; and

                  (ii) Debit to such Capital Account the items described in
      Sections 1.704-1(b)(2)(ii)(d)(4), 1.704-1(b)(2)(ii)(d)(5) and
      1.704-1(b)(2)(ii)(d)(6) of the Treasury Regulations.

      The foregoing definition of Adjusted Capital Account Deficit is intended
to comply with the provisions of Section 1.704-1(b)(2)(ii)(d) of the Treasury
Regulations and shall be interpreted consistently therewith.

            (g) "Affiliate" means, with respect to any Person any other Person
that directly or indirectly through one or more intermediaries controls or is
controlled by or is under common control with the Person. The terms "controls",
"controlled by" and "under common control with" shall mean the possession,
directly or indirectly or through one or more intermediaries, of more than fifty
percent (50%) of the outstanding voting stock of, or the power to direct or
cause the direction


                                        2
<PAGE>   11
of the management policies of any Person, whether through ownership of stock, as
a general partner or trustee, by contract or otherwise.

            (h) "Affiliate Transaction" means a business transaction between the
Company or the Partnership and any Member, Limited Partner or any Affiliate
thereof; provided, however, that "Affiliate Transaction" shall not include the
Project Agreements or any transaction between the Partnership and a Member or a
Limited Partner or any Affiliate thereof for transmission of natural gas or
other services offered by the Partnership relating to the Millennium Pipeline
System.

            (i) "Allocation Year" means (i) the period commencing on the
Effective Date and ending on December 31, 1998, (ii) any subsequent twelve (12)
month period commencing on January 1 and ending on December 31 or (iii) any
portion of the periods described in clauses (i) or (ii) for which the Company is
required to allocate Profits, Losses and other items of Company income, gain,
loss or deduction pursuant to Article 5 hereof.

            (j) "Available Cash" means all cash funds of the Company on hand
from time to time (other than cash funds obtained as Capital Contributions and
cash funds obtained from loans to the Company) after (i) payment of all
operating expenses of the Company as of such time, (ii) provision for the
payment of all outstanding and unpaid current obligations of the Company as of
such time and (iii) provision for a working capital reserve in an amount to be
determined by the Members.

            (k) "Bankrupt Member" means a Member that becomes subject to a
Bankruptcy.

            (l) "Bankruptcy" means, with respect to any Person, a Voluntary
Bankruptcy or an Involuntary Bankruptcy. A "Voluntary Bankruptcy" means, with
respect to any Person (i) the inability of such Person generally to pay its
debts as such debts become due or an admission in writing by such Person of its
inability to pay its debts generally or a general assignment by such Person for
the benefit of creditors, (ii) the filing of any petition or answer by such
Person seeking to adjudicate itself as bankrupt or insolvent, or seeking for
itself any liquidation, winding up, reorganization, arrangement, adjustment,
protection, relief or composition of such Person or its debts under any law
relating to bankruptcy, insolvency, reorganization or relief of debtors, or
seeking, consenting to or acquiescing in the entry of an order for relief or the
appointment of a receiver, trustee, custodian or other similar official for such
Person or for any substantial part of its property or (iii) corporate action
taken by such Person to authorize any of the actions set forth above. An
"Involuntary Bankruptcy" means, with respect to any Person, without the consent
or acquiescence of such Person, the entering of an order for relief or approving
a petition for relief or reorganization or any other petition seeking any
reorganization, arrangement, composition, readjustment, liquidation, dissolution
or other similar relief under any present or future bankruptcy, insolvency or
similar statute, law or regulation, or the filing of any such petition against
such Person which petition shall not be dismissed within ninety (90) days, or,
without the consent or acquiescence of such Person, the entering of an order
appointing a trustee, custodian, receiver or liquidator of such Person


                                        3
<PAGE>   12
or of all or any substantial part of the property of such Person which order
shall not be dismissed within ninety (90) days.

            (m) "Base Interest Rate" means a rate per annum equal to the lesser
of (a) two percent (2%) plus the Prime Rate and (b) the maximum rate permitted
by applicable law.

            (n) "Budget" means the annual operating budget for the Company and
the Partnership prepared by the Management Committee and approved by the Members
as provided in these Regulations and any other budget approved by the Members.

            (o) "Business Day" means any day other than a Saturday, Sunday or a
holiday on which national banking associations in the State of New York are
closed.

            (p) "Capacity Lease and Exchange Agreement" means that certain
Capacity Lease and Exchange Agreement to be entered into between the Partnership
and Columbia relating to the lease of capacity by Columbia on the Millennium
Pipeline System.

            (q) "Capital Account" means, with respect to any Member, the Capital
Account maintained for such Member in accordance with the following provisions:

                  (i) To each Member's Capital Account there shall be credited
      (A) such Member's Capital Contributions, (B) such Member's distributive
      share of Profits and any items in the nature of income or gain which are
      specially allocated pursuant to Sections 5.03 or 5.04 hereof and (C) the
      amount of any Company liabilities assumed by such Member or which are
      secured by any Property distributed to such Member; provided, however,
      that the principal amount of a promissory note which is not readily traded
      on an established securities market and which is contributed to the
      Company by the maker of the note (or a Member related to the maker of the
      note within the meaning of Treasury Regulations Section
      1.704-1(b)(2)(ii)(c)) shall not be included in the Capital Account of any
      Member until the Company makes a taxable disposition of the note or until
      (and to the extent) principal payments are made on the note, all in
      accordance with Treasury Regulations Section 1.704-1(b)(2)(iv)(d)(2);

                  (ii) To each Member's Capital Account there shall be debited
      (A) the amount of money and the Gross Asset Value of any property
      distributed to such Member pursuant to any provision of these Regulations,
      (B) such Member's distributive share of Losses and any items in the nature
      of expenses or losses which are specially allocated pursuant to Sections
      5.03 or 5.04 hereof and (C) the amount of any liabilities of such Member
      assumed by the Company or which are secured by any property contributed by
      such Member to the Company;


                                        4
<PAGE>   13
                  (iii) In the event Membership Interests are transferred in
      accordance with the terms of these Regulations, the transferee shall
      succeed to the Capital Account of the transferor in proportion to the
      Membership Interest transferred; and

                  (iv) In determining the amount of any liability for purposes
      of subparagraphs (i) and (ii) above, there shall be taken into account
      Code Section 752(c) and any other applicable provisions of the Code and
      Treasury Regulations.

                  (v) The foregoing provisions and the other provisions of these
      Regulations relating to the maintenance of Capital Accounts are intended
      to comply with Treasury Regulations Section 1.704-1(b), and shall be
      interpreted and applied in a manner consistent with such Treasury
      Regulations. In the event the Members shall determine that it is prudent
      to modify the manner in which the Capital Accounts or any debits or
      credits thereto (including, without limitation, debits or credits relating
      to liabilities which are secured by contributed or distributed property or
      which are assumed by the Company or any Member), are computed in order to
      comply with such Treasury Regulations, the Members may make such
      modification, provided that it is not likely to have a material effect on
      the amounts distributed to any Person pursuant to Article 13 hereof upon
      the dissolution of the Company. The Members also shall make (i) any
      adjustments that are necessary or appropriate to maintain equality between
      the Capital Accounts of the Members and the amount of capital reflected on
      the Company's balance sheet, as computed for book purposes, in accordance
      with Treasury Regulations Section 1.704-1(b)(2)(iv)(q), and (ii) any
      appropriate modifications in the event unanticipated events might
      otherwise cause these Regulations not to comply with Treasury Regulations
      Section 1.704-1(b).

            (r) "Capital Contributions" means, with respect to any Member, the
amount of money and/or the initial Gross Asset Value of any property other than
money (net of any liabilities assumed or taken subject to) actually contributed
to the Company with respect to the Membership Interests held or purchased by
such Member, including, without limitation, Initial Capital Contributions,
Scheduled Capital Contributions and Additional Capital Contributions.

            (s) "Certificate" or "Certificate of Formation" means the
certificate of formation filed with the Secretary of State of the State of
Delaware pursuant to the Act to form the Company, as originally executed and
amended, modified, supplemented or restated from time to time, as the context
requires, and as described in Section 2.01 hereof.

            (t) "Certificate of Dissolution" means the certificate of
dissolution filed with the Secretary of State of the State of Delaware pursuant
to the Act to dissolve the Company, as described in Section 13.04 hereof.

            (u) "Change in Control" means the Disposition of (i) a controlling
interest in a Member to a Person that is not an Affiliate of the Member or (ii)
a controlling interest in a Member Owner to a Person that is not an Affiliate of
the Member Owner or the Member; provided, however,


                                        5
<PAGE>   14
that "Change in Control" shall not include a Disposition of the interests of
such Member Owner in the Millennium Pipeline System, held through the Member,
which exceeds eighty percent (80%) of the value of such Member Owner. For
purposes of this subsection 1.01(u)(ii), (A) a Disposition shall not include a
mortgage, pledge, grant of a security interest or other disposition or
encumbrance and (B) "controlling interest" shall mean possession, directly or
indirectly, of power to direct or cause the direction of management or policies
of a Person (whether through ownership of securities, partnership, limited
liability company or other ownership interests by contract or otherwise).

            (v) "Code" means the United States Internal Revenue Code of 1986, as
amended from time to time, and any successor statute.

            (w) "Columbia" means Columbia Gas Transmission Corporation, a
Delaware corporation.

            (x) "Commitment Voting Date" means the date on which the Members
make the determination to commit the Partnership to purchase all or
substantially all of the pipe necessary to construct the Millennium Pipeline
System or such other date as determined to be appropriate by the Members to
commit to commence construction of the Millennium Pipeline System, taking into
consideration criteria developed by the Management Committee from time to time;
provided, however, that any vote of the Members which is intended to establish
the Commitment Voting Date shall not occur earlier than thirty (30) days after
the date notice for such vote is sent to the Members pursuant to Section 15.04
hereof.

            (y) "Company" means Millennium Pipeline Management Company, L.L.C.,
a Delaware limited liability company.

            (z) "Contribution Agreement" means that certain Contribution
Agreement to be entered into between the Partnership and Columbia relating to
the contribution of Columbia of property as part of its Capital Contribution to
the Partnership.

            (aa) "Contribution Date" shall have the meaning set forth in Section
4.02 hereof.

            (bb) "Credit Support Documents" means (i) a guaranty or (ii) such
other form of credit support acceptable to the Members.

            (cc) "Debt" means (i) any indebtedness for borrowed money or the
deferred purchase price of property as evidenced by a note, bonds or other
instruments, (ii) obligations as lessee under capital leases, (iii) obligations
secured by any mortgage, pledge, security interest, encumbrance, lien or charge
of any kind existing on any asset owned or held by the Company whether or not
the Company has assumed or become liable for the obligations secured thereby,
(iv) any obligation under any interest rate swap agreement, (v) accounts payable
and (vi) obligations under direct or indirect guarantees of (including
obligations, contingent or otherwise, to assure a creditor against loss in
respect of) indebtedness or obligations of the kinds referred to in clauses (i),


                                        6
<PAGE>   15
(ii), (iii), (iv) and (v), above; provided that Debt shall not include
obligations in respect of any accounts payable that are incurred in the ordinary
course of the Company's business and are either not delinquent or are being
contested in good faith by appropriate proceedings.

            (dd) "Delinquent Member" shall have the meaning set forth in Section
4.03(a) hereof.

            (ee) "Depreciation" means, for each Allocation Year, an amount equal
to the depreciation, amortization or other cost recovery deduction allowable
with respect to an asset for such Allocation Year, except that if the Gross
Asset Value of an asset differs from its adjusted basis for federal income tax
purposes at the beginning of such Allocation Year, Depreciation shall be an
amount which bears the same ratio to such beginning Gross Asset Value as the
federal income tax depreciation, amortization or other cost recovery deduction
for such Allocation Year bears to such beginning adjusted tax basis; provided,
however, that, if the adjusted basis for federal income tax purposes of an asset
at the beginning of such Allocation Year is zero, Depreciation shall be
determined with reference to such beginning Gross Asset Value using any
reasonable method approved by the Members.

            (ff) "DGCL" means the Delaware General Corporation Law and any
successor statute, as amended from time to time.

            (gg) "Dispose," "Disposing" or "Disposition" shall each mean a sale,
assignment, transfer, exchange, mortgage, pledge, grant of a security interest
or other disposition or encumbrance (including, without limitation, by operation
of law).

            (hh) "Dispute" shall have the meaning set forth in Section 14.01
hereof.

            (ii) "Dissolution Event" shall have the meaning set forth in Section
13.01 hereof.

            (jj) "Effective Date" means the last to occur of (i) the date these
Regulations are executed by the initial Members and (ii) the date the
Certificate of Formation is filed with the Secretary of State of the State of
Delaware.

            (kk) "Encumbrance" means any security interest, mortgage, pledge,
claim, lien, charge, option, right of first refusal, preferential purchase
right, defect, encumbrance or other right or interest in the assets of a Person.

            (ll) "Excess Withholding Liability" means any amount of withholding
due from a foreign Member's share of allocable income in excess of the Available
Cash which, but for the withholding requirement, would have been distributed to
such Member during such Allocation Year.


                                        7
<PAGE>   16
            (mm) "FERC" means the Federal Energy Regulatory Commission or any
commission, agency or other governmental body succeeding to the power of such
commission under the Natural Gas Act.

            (nn) "General Interest Rate" means a rate per annum equal to the
lesser of (i) one percent (1%) plus the Prime Rate and (ii) the maximum rate
permitted by applicable law.

            (oo) "Gross Asset Value" means, with respect to any asset, the
asset's adjusted basis for federal income tax purposes, except as follows:

                  (i) The initial Gross Asset Value of any asset contributed by
      a Member to the Company shall be the gross fair market value of such
      asset, as determined by the Members;

                  (ii) The Gross Asset Values of all Company assets shall be
      adjusted to equal their respective gross fair market values (taking Code
      Section 7701(g) into account), as determined by the Members as of the
      following times: (A) the acquisition of an additional interest in the
      Company by any new or existing Member in exchange for more than a de
      minimis Capital Contribution; (B) the distribution by the Company to a
      Member of more than a de minimis amount of property as consideration for
      an interest in the Company; provided, that either or both of the
      adjustments described in clauses (A) and (B) of this paragraph shall be
      made only if the Members reasonably determine that such adjustment is
      necessary to reflect the relative economic interests of the Members;

                  (iii) The Gross Asset Value of any item of Company assets
      distributed to any Member shall be adjusted to equal the gross fair market
      value (taking Code Section 7701(g) into account) of such asset on the date
      of distribution as determined by the Members; and

                  (iv) The Gross Asset Values of Company assets shall be
      increased (or decreased) to reflect any adjustments to the adjusted basis
      of such assets pursuant to Code Sections 734(b) or 743(b), but only to the
      extent that such adjustments are taken into account in determining Capital
      Accounts pursuant to Treasury Regulations Section 1.704-1(b)(2)(iv)(m)
      and subparagraph (vi) of the definition of "Profits" and "Losses" or
      Section 5.3(c) hereof; provided, however, that Gross Asset Values shall
      not be adjusted pursuant to this subparagraph (iv) to the extent that an
      adjustment pursuant to subparagraph (ii) of this subsection (pp) is
      required in connection with a transaction that would otherwise result in
      an adjustment pursuant to this subparagraph (iv).

      If the Gross Asset Value of an asset has been determined or adjusted
      pursuant to subparagraph (ii) or (iv) above, such Gross Asset Value shall
      thereafter be adjusted by the Depreciation taken into account with respect
      to such asset for purposes of computing Profits and Losses.


                                        8
<PAGE>   17
            (pp) "Information Request" shall have the meaning set forth in
Section 14.03 hereof.

            (qq) "Initial Capital Contributions" means the amount in cash
contributed to the Company pursuant to Section 4.01 hereof by the Members.

            (rr) "In-Service Date" shall have the meaning set forth in
subsection 3.14(c) hereof.

            (ss) "Interested Matters Voting Procedures" shall have the meaning
set forth in Section 7.01(d) hereof.

            (tt) "Lake Crossing Agreement" means that certain Lake Crossing
Agreement to be entered into between TransCanada or an Affiliate of TransCanada
and Columbia in its capacity as the project developer under the Project
Development Agreement relating to the construction of the segment of the
Millennium Pipeline System which will pass under Lake Erie.

            (uu)  "Limited Partner" means a limited partner of the Partnership.

            (vv) "Losses" shall have the meaning set forth in Section 1.01 (vvv)
hereof.

            (ww) "Majority Approval" means the approval by one or more Members
having among them in excess of 50% of the Membership Interests of all Members
that are not Withdrawing Members.

            (xx) "Management Committee" shall have the meaning set forth in
Section 7.02(d) hereof.

            (yy) "Market Value" means that price that a willing and able buyer
would pay to a Member willing to sell its Membership Interest, or a portion
thereof, neither being under any compulsion to buy or to sell, and both having
reasonable knowledge of the relevant facts. The Market Value of a Membership
Interest shall be determined by a duly qualified and experienced appraiser
mutually acceptable to the Members. If the Members are unable to agree on such
an appraiser within fifteen (15) days of the event giving rise to the need for
an appraiser, each Member shall select an experienced and qualified appraiser
within five (5) days and these two appraisers shall select a third appraiser
within ten (10) days. This third appraiser shall then determine the Market Value
of the Membership Interests for which an appraisal is sought. The Market Value
so determined shall be binding on all Members.

            (zz) "MCN" means MCNIC LLC Millennium Company, a Michigan
corporation.

            (aaa) "Member Agreement" means any written agreement entered into
among all Members that are not Withdrawing Members.


                                        9
<PAGE>   18
            (bbb) "Member Nonrecourse Debt" shall have the same meaning as the
term "member nonrecourse debt" in Section 1.704-2(b)(4) of the Treasury
Regulations.

            (ccc) "Member Nonrecourse Debt Minimum Gain" means an amount, with
respect to each Member Nonrecourse Debt, equal to the Company Minimum Gain that
would result if such Member Nonrecourse Debt were treated as nonrecourse as
determined in accordance with Section 1.704-2(i)(3) of the Treasury Regulations.

            (ddd) "Member Nonrecourse Deductions" shall have the same meaning as
the term "member nonrecourse deductions" in Sections 1.704-2(i)(1) and
1.704-2(i)(2) of the Treasury Regulations.

            (eee) "Member Owner" means the Person or Persons that own, of record
or beneficially, all of the capital stock or equity interests in a Member.

            (fff) "Members" collectively means those Persons adopting and
executing these Regulations on the date hereof or any Person hereafter admitted
to the Company as a Member in accordance with these Regulations, but does not
include any Person who has ceased to be a Member as provided in these
Regulations.

            (ggg) "Membership Interest" means the percentage ownership interest
of a Member in the Company, including without limitation, rights to
distributions (liquidating or otherwise), allocations, information, and to
consent to or approve actions of the Company. The initial Membership Interest of
each Member shall be as set forth on Exhibit A hereof. The Membership Interest
of each Partner shall be adjusted from time to time (i) based upon the Capital
Contributions made by the Members in accordance with Article 4 hereof, with the
Membership Interest of each Member being equal to a fraction, the numerator of
which is a Member's cumulative Capital Contributions and the denominator of
which is the cumulative total of all Members' Capital Contributions; and (ii)
upon the withdrawal of a Member, in which case the Membership Interest of the
Withdrawing Member shall, as of the Withdrawal Effective Date, be distributed
pro rata among all of the non-withdrawing Members in a portion equal to the
ratio of (A) the pre-withdrawal Membership Interest of such non-withdrawing
Member to (B) the sum of all pre-withdrawal Membership Interests of all
non-withdrawing Members.

            (hhh) "Millennium Pipeline System" shall have the meaning set forth
in the Preamble to these Regulations.

            (iii) "Millennium Pipeline Company, L.P." means that certain
Delaware limited partnership with the Company, as general partner, and Columbia,
MCN, TransCanada and Westcoast, each as limited partners. This term may be used
interchangeably with "Partnership".


                                       10
<PAGE>   19
            (jjj) "MOU" means that certain Memorandum of Understanding dated as
of December 1, 1997, among Columbia, Westcoast Energy (U.S.) Inc., MCN
Investment Corporation and TransCanada PipeLines Limited, as amended, modified
and extended.

            (kkk) "Net Cash Flow" means the gross cash proceeds of the Company
less the portion thereof used to pay or establish working capital reserves for
all Company expenses, debt payments, capital improvements, replacements and
contingencies, all as determined by the Members. Net Cash Flow shall not be
reduced by depreciation, amortization, cost recovery deductions or similar
allowances, but shall be increased by any reductions of reserves previously
established pursuant to the first sentence of this definition.

            (lll) "Nonrecourse Deductions" shall have the same meaning as set
forth in Section 1.704-2(b)(1) of the Treasury Regulations.

            (mmm) "Nonrecourse Liability" shall have the same meaning as set
forth in Section 1.704-2(b)(3) of the Treasury Regulations.

            (nnn) "Notice Period" shall have the meaning set forth in Section
3.07 hereof.

            (ooo) "Offeree Member" shall have the meaning set forth in Section
3.07 hereof.

            (ppp) "O&M Agreement" means that certain Operations, Maintenance and
Management Services Agreement to be entered into by the Partnership and Columbia
pertaining to the operation and maintenance of the Millennium Pipeline.

            (qqq) "Partnership" means Millennium Pipeline Company, L.P.

            (rrr) "Partnership Agreement" means the Agreement of Limited
Partnership of Millennium Pipeline Company, L.P., as the same may be amended and
modified from time to time.

            (sss) "Person" shall have the meaning set forth in Section
18-101(12) of the Act.

            (ttt) "Precedent Agreements" means the Precedent Agreements entered
into on behalf of the Partnership with proposed customers of the Partnership for
the transmission of natural gas through the Millennium Pipeline System.

            (uuu) "Prime Rate" means the fluctuating per annum rate of interest
announced from time to time by Citibank, N.A. as its "Prime Rate".

            (vvv) "Profits" and "Losses" mean, for each Allocation Year, an
amount equal to the Company's taxable income or loss for such Allocation Year,
determined in accordance with Code Section 703(a) (for purposes of such
determination, all items of income, gain, loss, or


                                       11
<PAGE>   20
deduction required to be stated separately pursuant to Code Section 703(a)(1)
shall be included in taxable income or loss), with the following adjustments
(without duplication):

                  (i) Any income of the Company exempt from federal income tax
      and not otherwise taken into account in computing Profits or Losses
      pursuant to this definition of "Profits" and "Losses" shall be added to
      such taxable income or loss;

                  (ii) Any expenditures of the Company described in Code Section
      705(a)(2)(B) or treated as Code Section 705(a)(2)(B) expenditures pursuant
      to Treasury Regulations Section 1.704-1(b)(2)(iv)(i) and not otherwise
      taken into account in computing Profits or Losses pursuant to this
      definition of "Profits" and "Losses" shall be subtracted from such taxable
      income or loss;

                  (iii) In the event the Gross Asset Value of any Company asset
      is adjusted pursuant to subparagraphs (ii) or (iii) of the definition of
      Gross Asset Value, the amount of such adjustment shall be treated as an
      item of gain (if the adjustment increases the Gross Asset Value of the
      asset) or an item of loss (if the adjustment decreases the Gross Asset
      Value of the asset) from the disposition of such asset and shall be taken
      into account for purposes of computing Profits or Losses;

                  (iv) Gain or loss resulting from any Disposition of Property
      with respect to which gain or loss is recognized for federal income tax
      purposes shall be computed by reference to the Gross Asset Value of the
      Property Disposed of, notwithstanding that the adjusted tax basis of such
      Property differs from its Gross Asset Value;

                  (v) In lieu of the depreciation, amortization and other cost
      recovery deductions taken into account in computing such taxable income or
      loss, there shall be taken into account Depreciation for such Allocation
      Year, computed in accordance with the definition of Depreciation;

                  (vi) To the extent an adjustment to the adjusted tax basis of
      any Company asset pursuant to Code Section 734(b) is required, pursuant to
      Treasury Regulations Section 1.704-1(b)(2)(iv)(m)(4), to be taken into
      account in determining Capital Accounts as a result of a distribution
      other than in liquidation of a Membership Interest, the amount of such
      adjustment shall be treated as an item of gain (if the adjustment
      increases the basis of the asset) or loss (if the adjustment decreases
      such basis) from the Disposition of such asset and shall be taken into
      account for purposes of computing Profits or Losses; and

                  (vii) Notwithstanding any other provision of this definition,
      any items which are specially allocated pursuant to Sections 5.03 or 5.04
      hereof shall not be taken into account in computing Profits or Losses.


                                       12
<PAGE>   21
            The amounts of the items of Company income, gain, loss or deduction
      available to be specially allocated pursuant to Sections 5.03 and 5.04
      hereof shall be determined by applying rules analogous to those set forth
      in subparagraphs (i) through (vi) above.

            (www) "Project Agreements" means the Capacity Lease and Exchange
Agreement, the Contribution Agreement, the Lake Crossing Agreement, the O&M
Agreement, the Project Development Agreement and the Precedent Agreements, as
the same may be amended and modified from time to time.

            (xxx) "Project Development Agreement" means that certain Project
Development and Management Services Agreement to be entered into between the
Partnership and Columbia relating to the development and construction of the
Millennium Pipeline System.

            (yyy) "Property" means any property owned or leased by the Company.

            (zzz) "PUHCA" means the Public Utility Holding Company Act of 1935,
as amended.

            (aaaa)"PUHCA Company" shall have the meaning set forth in Section
3.09 hereof.

            (bbbb)"Reconstitution Period" shall have the meaning set forth in
Section 13.05 hereof.

            (cccc)"Regulations" shall have the meaning set forth in the
introductory paragraph hereof.

            (dddd)"Regulatory Allocations" shall have the meaning set forth in
Section 5.04 hereof.

            (eeee)"Required Accounting Practices" means generally accepted
accounting principles as practiced in the United States at the time prevailing
for companies engaged in a business similar to the Company or, if inconsistent
therewith, the accounting rules and regulations, if any, at the time prescribed
by the regulating body or bodies under the jurisdiction of which the Company is
at the time operating.

            (ffff)"Required Interest" means the affirmative vote of the Members
as required by Section 7.01 hereof.

            (gggg)"Sale Notice" shall have the meaning set forth in Section 3.07
hereof.

            (hhhh)"Scheduled Capital Contributions" shall have the meaning set
forth in Section 4.01 hereof.


                                       13
<PAGE>   22
            (iiii)"Super Majority Approval" means Majority Approval plus, if
there are four (4) Members that are not Withdrawing Members, the affirmative
vote of not fewer than three (3) Members. If there are fewer than four (4)
Members that are not Withdrawing Members or if the Interested Matters Voting
Procedures are applicable, "Super Majority Approval" means the approval by one
or more Members having among them in excess of 66-2/3% of the Membership
Interests of all Members that are not Withdrawing Members.

            (jjjj)"System Modification" shall mean any facilities to be
installed or action to be taken costing in excess of One Million Dollars
(US$1,000,000) to modify, improve, expand or increase the capacity of the
Millennium Pipeline System or any portion thereof after the Commitment Voting
Date (except in connection with customary maintenance and except for
modifications which in the reasonable judgment of the Chairman of the Management
Committee (a) do not result in an expansion of the capacity or a change in the
essential design of the Millennium Pipeline System or (b) are necessary to
comply with applicable environmental or safety requirements).

            (kkkk)"Third Party Terms" shall have the meaning set forth in
Section 3.07 hereof.

            (llll)"TransCanada" means TransCanada PipeLine USA Ltd., a Nevada
corporation.

            (mmmm) "Treasury Regulations" means the Income Tax Regulations,
including Temporary Regulations, promulgated under the Code, as such regulations
are issued, supplemented and amended from time to time.

            (nnnn)"UCC" means the Uniform Commercial Code of the State of
Delaware, as amended from time to time.

            (oooo) "Unanimous Approval" means the affirmative vote of the Member
or Members with all of the Membership Interests of all Members that are not
Withdrawing Members.

            (pppp)"Westcoast" means Westcoast Power Marketing Inc., a Delaware
corporation.

            (qqqq)"Withdrawal Effective Date" shall have the meaning set forth
in subsection 3.14(b) hereof.

            (rrrr)"Withdrawal Notice" shall have the meaning set forth in
Section 3.14(a) hereof.

            (ssss)"Withdrawal Period" shall have the meaning set forth in
Section 3.14(f) hereof.



                                       14
<PAGE>   23
            (tttt)"Withdrawing Member" shall have the meaning set forth in
Section 3.14(a) hereof.

      Other capitalized terms defined in other sections of these Regulations
have the meanings given them in such sections throughout the Regulations.

      1.02 Construction. The headings in these Regulations are inserted for
convenience of reference only and shall not affect the interpretation of these
Regulations. Whenever the context requires, each term stated in either the
singular or the plural shall include the singular and the plural, and the gender
of all words used in these Regulations includes the masculine, the feminine and
the neuter. Except as otherwise noted, references to Articles and Sections refer
to articles and sections of these Regulations and all references to Exhibits are
to exhibits attached hereto, each of which is made a part hereof for all
purposes. Use of the word "including" shall mean without limitation by reason of
enumeration.

                                  ARTICLE 2.

                                 ORGANIZATION

      2.01 Formation. The Company has been organized under the Act as a Delaware
limited liability company. The Secretary of State of Delaware issued a
Certificate of Formation on May 22, 1998 (the "Certificate"), upon the filing of
a Certificate of Formation for the Company by the organizer.

      2.02 Name. The name of the Company is "Millennium Pipeline Management
Company, L.L.C." and all Company business shall be conducted in that name or
such other names that comply with applicable law as the Members may select from
time to time.

      2.03 Registered Office; Registered Agent; Principal Office in the United
States; Other Offices. The registered office of the Company required by the Act
to be maintained in the State of Delaware shall be in the office of the initial
registered agent named in the Certificate or such other office (which need not
be a place of business of the Company) as the Members may designate from time to
time in the manner provided by law. The registered agent of the Company in the
State of Delaware shall be the initial registered agent named in the Certificate
or such other Person or Persons as the Members may designate from time to time
in the manner provided by law. The principal office of the Company in the United
States shall be at such place as the Members may designate from time to time,
which need not be in the State of Delaware, and the Company shall maintain
records there. The Company may have such other offices as the Members may
designate from time to time.

      2.04 Purposes. The purposes of the Company are those set forth in the
Certificate. Notwithstanding the provision in the Certificate relating to the
Company's purposes, the Members agree that, solely with respect to these
Regulations, the internal affairs of the Company and the


                                       15
<PAGE>   24
relationship of the Members, the purpose of the Company is to acquire and own a
general partnership interest in and to act as general partner of the Partnership
and to engage in any other business or activity that now or hereafter may be
necessary, incidental, proper, advisable or convenient to accomplish the
foregoing purpose that is not forbidden by the law of the jurisdiction in which
the Company engages in that business.

      2.05 Foreign Qualification. Prior to the Company's conducting business in
any jurisdiction other than Delaware, the Members shall cause the Company to
comply, to the extent procedures are available and those matters are reasonably
within the control of the Members, with all requirements necessary to qualify
the Company as a foreign limited liability company in that jurisdiction. At the
request of the Member(s), each Member shall execute, acknowledge, swear to and
deliver all certificates and other instruments conforming with these Regulations
that are necessary or appropriate to qualify, continue or terminate the Company
as a foreign limited liability company in all such jurisdictions in which the
Company may conduct business.

      2.06 Term. The Company commenced effective as of the Effective Date and
shall continue in existence for the period fixed in the Certificate for the
duration of the Company, or such earlier time as these Regulations may specify.

      2.07 Mergers and Exchanges. The Company may be a party to a merger or an
exchange or acquisition of the type described in Section 18-209 of the Act.

      2.08 Tax Partnership; No State-Law Partnership. The Members intend that
the Company be taxed as a partnership under the Code, but that the Company not
be a partnership (including, without limitation, a limited partnership) or joint
venture, and that no Member be a partner or joint venturer of any other Member,
for any purposes other than federal and state tax purposes, and these
Regulations shall not be construed to suggest otherwise.

                                  ARTICLE 3.

                     MEMBERSHIP; DISPOSITIONS OF INTERESTS

      3.01 Initial Members. The initial Members are the Persons executing these
Regulations as Members as of the date of these Regulations, each of which is
admitted as a Member effective contemporaneously with the execution of these
Regulations by such Member.

      3.02 Membership. The initial Members shall all be of the same class. Each
Member shall make the Initial Capital Contributions identified on Exhibit A and
the initial Membership Interests shall be as set forth on Exhibit A. Each Member
shall be entitled to one (1) vote for its Membership Interest in the Company on
all matters presented to the Members for a vote, and the vote of each Member
shall be determined on the basis of the Membership Interest of each Member.


                                       16
<PAGE>   25
      3.03  Representations and Warranties.

            (a) In General. As of the date hereof, each Member hereby makes each
of the representations and warranties applicable to such Member as set forth
below, and such warranties and representations shall survive the execution and
adoption of these Regulations.

            (b) Representations and Warranties. Each Member hereby represents
and warrants that:

                  (i) Due Incorporation or Formation; Authorization of
      Regulations. Such Member is a corporation duly organized or a partnership,
      limited liability company or other entity duly formed, validly existing
      and in good standing under the laws of the jurisdiction of its
      incorporation or formation and has the corporate, partnership or company
      power and authority to own its property and carry on its business as owned
      and carried on as of the date hereof and as contemplated hereby. Such
      Member is duly licensed or qualified to do business and is in good
      standing in each of the jurisdictions in which the failure to be so
      licensed or qualified would have a material adverse effect on its
      financial condition or its ability to perform its obligations hereunder.
      Such Member has the corporate, partnership or company power and authority
      to execute and deliver these Regulations and to perform its obligations
      hereunder, and the execution, delivery and performance of these
      Regulations has been duly authorized by all necessary corporate,
      partnership or company action. These Regulations constitute the legal,
      valid and binding obligation of such Member.

                  (ii) No Conflict with Restrictions; No Default. Neither the
      execution, delivery and performance of these Regulations nor the
      consummation by such Member of the transactions contemplated hereby will
      (i) conflict with, violate or result in a breach of any of the terms,
      conditions or provisions of any law, regulation, order, writ, injunction,
      decree, determination or award of any court, governmental department,
      board, agency or instrumentality, domestic or foreign, or any arbitrator,
      applicable to such Member, (ii) conflict with, violate, result in a breach
      of, or constitute a default under any of the terms, conditions or
      provisions of the articles or certificate of incorporation, bylaws,
      partnership agreement or operating agreement of such Member or of any
      material agreement or instrument to which such Member is a party or by
      which such Member is or may be bound or to which any of its material
      properties or assets is subject, (iii) conflict with, violate, result in a
      breach of, constitute a default under (whether with notice or lapse of
      time or both), accelerate or permit the acceleration of the performance
      required by, give to others any material interests or rights, or require
      any consent, authorization or approval under any indenture, mortgage,
      lease agreement or instrument to which such Member is a party or by which
      such Member is or may be bound or (iv) result in the creation or
      imposition of any lien upon any of the material properties or assets of
      such Member.

                  (iii) Governmental Authorizations. Any registration,
      declaration or filing with, or consent, approval, license, permit or other
      authorization or order by, any


                                       17
<PAGE>   26
      governmental or regulatory authority, domestic or foreign, that is
      required in connection with the valid execution, delivery, acceptance and
      performance by such Member under these Regulations or the consummation by
      such Member of any transaction contemplated hereby has been completed,
      made or obtained on or before the date hereof.

                  (iv) Litigation. There are no actions, suits, proceedings or
      investigations pending or, to the knowledge of such Member, threatened
      against or affecting such Member or any of its properties, assets or
      businesses in any court or before or by any governmental department,
      board, agency or instrumentality, domestic or foreign, or any arbitrator
      which could, if adversely determined (or, in the case of an investigation,
      could lead to any action, suit or proceeding, which if adversely
      determined) could reasonably be expected to materially impair such
      Member's ability to perform its obligations under these Regulations or to
      have a material adverse effect on the consolidated financial condition of
      such Member; and such Member has not received any currently effective
      notice of any default, nor is such Member in default, under any applicable
      order, writ, injunction, decree, permit, determination or award of any
      court, governmental department, board, agency, or instrumentality,
      domestic or foreign, or any arbitrator which could reasonably be expected
      to materially impair such Member's ability to perform its obligations
      under these Regulations or to have a material adverse effect on the
      consolidated financial condition of such Member.

                  (v) Investment Company Act. Such Member is not, nor will the
      Company as a result of such Member holding an interest therein be, an
      "investment company" as defined in, or subject to regulation under, the
      Investment Company Act of 1940.

                  (vi) Investigation. Such Member is acquiring its Membership
      Interest based upon its own investigation, and the exercise by such Member
      of its rights and the performance of its obligations under these
      Regulations will be based upon its own investigation, analysis and
      expertise. Such Member is the sole party in interest as to its
      participation in the Company and such Member's acquisition of its
      Membership Interest is being made for its own account for investment and,
      in particular, such Member has no present agreement, understanding or
      arrangement to (A) subdivide its Membership Interest, (B) hold its
      Membership Interest in trust for any other Person or (C) Dispose of any
      portion thereof to any other Person except for the disposition of any
      Member's Membership Interest to an Affiliate of such Member. Such Member
      is a sophisticated investor possessing an expertise in analyzing the
      benefits and risks associated with acquiring investments that are similar
      to the acquisition of its Membership Interest. Prior to the acquisition of
      its Membership Interest, such Member and its representatives, if any, have
      had the opportunity to obtain ample information concerning the Company and
      its proposed activities.

            (vii) Ownership. Exhibit B hereto identifies the Member Owner(s) for
      each Member.


                                       18
<PAGE>   27
      3.04  Restrictions on the Disposition of Membership Interests.

            (a) Except as specifically provided in this Section 3.04, a
Disposition of all or part of a Membership Interest may not be affected without
the approval of the Required Interest. Any attempted Disposition by a Person of
a Membership Interest or other right in the Company other than in accordance
with this Section 3.04 shall be, and it hereby is, declared null and void ab
initio. Notwithstanding the foregoing, the Membership Interest of any Member may
be Disposed of without the approval of the Required Interest if such Disposition
(i) is to an Affiliate and (ii) does not violate any provision of the
Partnership Agreement.

            (b) No Member shall have the right to Dispose of a Membership
Interest or any part thereof, nor shall any Person have the right to request
admission to the Company as a Member in connection with such Disposition, prior
to the occurrence of the following events:

                  (i)   either--

                        (A) the Membership Interest or part thereof subject to
                        the Disposition or admission must be registered under
                        the Securities Act of 1933, as amended, and any
                        applicable state securities laws, or

                        (B) the Company must receive a favorable opinion by the
                        Company's legal counsel or by other legal counsel
                        acceptable to the Members to the effect that the
                        Disposition or admission is exempt from registration
                        under those laws; and

                  (ii) the right of first refusal set forth in Section 3.07
                  hereof shall have lapsed;

provided, however, the Members may waive the requirements of this Section
3.04(b).

            (c) The Member effecting a Disposition of all or any part of a
Membership Interest, and any Person admitted as a Member in connection
therewith, shall pay or reimburse the Company for all costs incurred by the
Company in connection with such Disposition or admission (including, without
limitation, the legal fees incurred in connection with the legal opinions
referred to in Section 3.04(b) hereof)on or before the tenth (10th) day after
the receipt by the Member or that Person of the Company's invoice for the amount
due. If payment is not made by the due date, the Person owing that amount shall
pay interest on the unpaid amount from the date due until paid, at a rate per
annum equal to the Base Interest Rate.

            (d) Notwithstanding the provisions of this Section 3.04, any
purported Disposition of all or any part of a Membership Interest shall be both
ineffective and invalid if such Disposition is (i) in violation of any provision
of the Partnership Agreement or (ii) not completed


                                       19
<PAGE>   28
contemporaneously with the Disposition of an equivalent percentage of the
limited partnership interest of the Member or its Affiliate that is a limited
partner in the Partnership.

      3.05 Additional Members. Additional Persons may be admitted as Members,
and Membership Interests may be created and issued to those Persons and to
existing Members with the approval of the Required Interest, on such terms and
conditions as the Members may determine at the time of admission. Upon the
creation and issuance of Membership Interests to any Person as an additional
Member of the Company, the Members shall reexamine and, if necessary,
redetermine the meaning of "Super Majority Approval." The terms of admission or
issuance must specify the Membership Interests applicable thereto and may
provide for the creation of different classes or groups of Members having
different rights, powers and duties. The Members shall reflect the creation of
any new class or group in an amendment to these Regulations indicating the
different rights, powers and duties. Any such admission shall be effective only
after the new Member has executed and delivered to the Members a document
including such new Member's notice address, its agreement to be bound by these
Regulations, and its representation and warranty that the representations and
warranties in Section 3.03 hereof are true and correct with respect to the new
Member. The provisions of this Section 3.05 shall not apply to (i) Dispositions
of Membership Interests or (ii) the admission of new Persons in substitution of
any existing Member.

      3.06 Membership Interests. For purposes of this Article 3, a Change in
Control shall be deemed to be a Disposition of a Membership Interest, and, as
such, shall be subject to the restrictions on the Disposition of a Membership
Interest contained in Section 3.04 hereof.

      3.07  Rights of First Refusal.

            (a) Subject to Section 3.09 hereof, at any time following the
Effective Date, any Member desiring to Dispose of all or any part of its
Membership Interest to a Person other than an Affiliate shall first have
received a written offer from the prospective purchaser, and, as a condition
precedent to its right to sell the Membership Interest, the selling Member shall
notify the Company and the other Members of its intention to Dispose of all or a
specified part of its Membership Interest. The notice shall be in writing
setting forth in detail the name of the prospective purchaser and the terms and
conditions of the proposed Disposition (the "Sale Notice") and shall offer to
Dispose of such Member's Membership Interest in the Company at the same price
and on the same terms and conditions ("Third Party Terms"). The Members' wholly
owned subsidiaries and designated Affiliates (each an "Offeree Member") shall
have the right within thirty (30) days after the delivery of the Sale Notice
(the "Notice Period") to purchase the Membership Interest on the Third Party
Terms. If more than one Offeree Member desires to purchase the remaining
Membership Interest, such Membership Interest shall be purchased by Offeree
Members in the proportion that each Offeree Member's Membership Interest bears
to the sum of all Offeree Member's Membership Interests. In the event the
Offeree Members do not elect to purchase all of the Membership Interests offered
by the selling Member on the Third Party Terms, then the selling Member shall be
free to Dispose of the Membership Interests in accordance with the Sale Notice,
subject to the other terms of these Regulations including Section 3.04 which
shall apply to any transferee. If such Disposition


                                       20
<PAGE>   29
does not occur within thirty (30) days after termination of the Notice Period,
the selling Member shall be required to again comply with all the provisions of
this Section 3.07.

            (b) If any Third Party Terms contemplate that all or any part of the
purchase price for the proposed Disposition of a Membership Interest will be
paid in any form other than cash, the fair market value of the offer shall be an
amount (in U.S. dollars) determined as follows: (i) cash payable at closing
shall be valued at the amount thereof in U.S. dollars, (ii) a security trading
on a public market and for which published trading prices are readily available
shall be valued at its closing sales price (or if a sales price is not available
at the average of its closing bid and asked prices) on the last Business Day
preceding the date of the offer with respect to such offer, and (iii) a security
not described in clause (ii) or other property, including cash payable in one or
more installments, shall be valued at its fair market value on the last Business
Day preceding the date of the offer, as determined by a majority vote of the
Members who are not Disposing Members, which determination shall be binding upon
the Member for purposes of determining the fair market value of the offer. If
the non-disposing Members, by majority vote, are unable or unwilling to agree on
the fair market value of the offer, the Members shall select an independent
appraiser to determine the fair market value of the offer, which determination
shall be binding upon the Members for purposes of determining the fair market
value of the offer.

      3.08 Restrictions Applicable Upon Disposition. The restrictions of these
Regulations will continue to be applicable upon the Disposition of any
Membership Interest, and any Person acquiring a Membership Interest shall
execute and become a party to these Regulations and shall hold such Membership
Interest subject to all of the terms and conditions provided herein, and no
further Disposition of such Membership Interest shall be made except in
accordance with the terms and conditions provided herein.

      3.09 PUHCA. Notwithstanding anything to the contrary in these Regulations,
any Disposition or acquisition of a Membership Interest permitted in these
Regulations shall not be permitted without approval of the Required Interest if
the effect of such Disposition or acquisition would cause the Company or the
Partnership to become (i) a "subsidiary company" of a "holding company"; (ii) an
"affiliate" of a "holding company"; or (iii) an "affiliate" of a "subsidiary
company" of a "holding company" (as such terms are defined in PUHCA) that is not
exempt from the obligations, duties and liabilities imposed by PUHCA
(collectively, a "PUHCA Company").

      3.10 Remedies. The Company and/or any Member shall have the right to
enforce its rights under this Article 3 by specific performance.


                                       21
<PAGE>   30
      3.11  Information; Confidentiality.

            (a) In addition to the other rights specifically set forth in these
Regulations, each Member is entitled to all information to which that Member is
entitled to have access pursuant to Section 18-305 of the Act under the
circumstances and subject to the conditions therein stated. Such information
shall be available for review during normal business hours.

            (b) The Members acknowledge that, from time to time, they may
receive information from or regarding the Company in the nature of trade secrets
or that otherwise is confidential, the release of which may be damaging to the
Company or Persons with which it does business. Each Member shall hold in strict
confidence any information it receives regarding the Company that is identified
as being confidential (which includes oral and written information, provided
that information provided in writing, it shall be so marked) and may not
disclose it to any Person other than another Member, except for disclosures (i)
compelled by law (but the Member must notify the other Members promptly of any
request for that information before disclosing it, if practicable), (ii) to
advisers or representatives of the Member or Persons to which a Member's
Membership Interest may be Disposed as permitted by these Regulations, but only
if the recipients have agreed to be bound by the provisions of this Section
3.11(b) or (iii) of information that a Member also has received from a source
independent of the Company that the Member reasonably believes obtained that
information without breach of any obligation of confidentiality. The Members
acknowledge that breach of the provisions of this Section 3.11(b) may cause
irreparable injury to the Company for which monetary damages are inadequate,
difficult to compute, or both. Accordingly, the Members agree that the
provisions of this Section 3.11(b) may be enforced by specific performance.

      3.12 Legends. Any instrument representing a Membership Interest shall
conspicuously bear the following legend:

      THE SECURITIES REPRESENTED BY THIS INSTRUMENT ARE SUBJECT TO RESTRICTIONS
      ON TRANSFER AND CERTAIN OTHER AGREEMENTS SET FORTH IN THE REGULATIONS OF
      THE COMPANY DATED EFFECTIVE AS OF MAY 31, 1998, A COPY OF WHICH MAY BE
      OBTAINED BY THE REGISTERED HOLDER OF THIS INSTRUMENT AT THE COMPANY'S
      PRINCIPAL PLACE OF BUSINESS.

      3.13 Liability to Third Parties. No Member shall be liable for the debts,
obligations or liabilities of the Company, including under a judgment decree or
order of a court.

      3.14  Withdrawal and Effect of Withdrawal.

            (a)   Prior to the Commitment Voting Date and subject to subsections
                  3.14(b), (c) and (d) below, any Member may elect to withdraw
                  as a Member from the Company by delivering notice of such
                  Member's intention to withdraw to the Company and the other
                  Members on or prior to the Commitment Voting Date


                                       22
<PAGE>   31
                  (the "Withdrawal Notice"). The Withdrawal Notice shall be
                  invalid if the Member or the Member's Affiliate that is a
                  partner in the Partnership does not also deliver a "Withdrawal
                  Notice" pursuant to the Partnership Agreement. Any Member
                  sending a valid Withdrawal Notice shall become a "Withdrawing
                  Member." From and after the Commitment Voting Date, a Member
                  shall have no right or power to withdraw as a Member from the
                  Company.

            (b)   To the extent the withdrawal of any Member would have the
                  effect of causing the Company to become a PUHCA Company, the
                  Withdrawal Notice shall not immediately affect the withdrawal
                  of the Member and withdrawal shall not occur until the earlier
                  of (i) receipt of Unanimous Approval and (ii) two hundred
                  seventy (270) days from the date of the Withdrawal Notice;
                  provided, however, that the non-Withdrawing Members shall
                  endeavor to accommodate the Withdrawing Member's withdrawal to
                  become effective prior to the expiration of the time period
                  described in subsection 3.14(b)(ii). If the withdrawal of the
                  Withdrawing Member would not have the effect of causing the
                  Company to become a PUHCA Company and the Withdrawing Member
                  delivers to the Company and the non-Withdrawing Members a
                  legal opinion to such effect, the effective date of the
                  withdrawal shall be the tenth (10th) day following the
                  Withdrawing Member's delivery of its Withdrawal Notice and
                  such legal opinion. The effective date of withdrawal pursuant
                  to this subsection 3.14(b) shall be referred to as the
                  "Withdrawal Effective Date."

            (c)   Upon delivery of the Withdrawal Notice, the Withdrawing Member
                  shall not (i) be entitled to any distributions from the
                  Company, (ii) be entitled to have representation on any
                  committee established by the Members or the Management
                  Committee, or (iii) have any obligation to make additional
                  Capital Contributions to the Company except Capital
                  Contributions relating to the expenditure of funds by the
                  Company which was approved by the Members prior to the
                  delivery of the Withdrawal Notice and Scheduled Capital
                  Contributions which are scheduled to be made prior to the
                  delivery of the Withdrawal Notice. A Withdrawing Member shall
                  be entitled to a return of the cash equivalent of the value of
                  its Capital Contributions; provided, that such return of
                  Capital Contributions shall not begin until after the date on
                  which the Millennium Pipeline System is fully operational and
                  in-service (the "In-Service Date"). Capital Contributions
                  shall be returned to a Withdrawing Member if and when
                  distributions are made to the non- Withdrawing Members as
                  provided in these Regulations and shall be paid to the
                  Withdrawing Member in one or more installments in amounts
                  equal to the sum that the Withdrawing Member would have
                  received if it had not become a Withdrawing Member (based upon
                  the Withdrawing Member's Interest at


                                       23
<PAGE>   32
                  the time of becoming a Withdrawing Member) until the
                  Withdrawing Member receives a sum equal to its aggregate
                  Capital Contributions. The undistributed sums to be
                  distributed to such Withdrawing Member shall begin to accrue
                  interest at the General Interest Rate from a date which
                  commences three (3) months after the In-Service Date.

            (d)   Except as provided in Section 3.14(b) hereof, withdrawal by a
                  Member may not occur without Unanimous Approval if the effect
                  of the withdrawal would be to cause the Company or the
                  Partnership to become a PUHCA Company.

            (e)   Withdrawal under this Section 3.14 shall be treated for tax
                  purposes as the redemption of all the Member's Membership
                  Interest for one dollar ($1.00).

            (f)   If a Withdrawing Member is made a party to or is threatened to
                  be made a party to or is involved in any Action or any appeal
                  of an Action during the period between the date of the
                  Withdrawal Notice and the Withdrawal Effective Date (the
                  "Withdrawal Period") or if any Action is brought (whether
                  during or after the Withdrawal Period) in which the
                  Withdrawing Member is made a party based upon events
                  transpiring during the Withdrawal Period, such Withdrawing
                  Member shall be indemnified by the Company. The rights granted
                  pursuant to this Section 3.14(f) shall be deemed contract
                  rights, and no amendment, modification or repeal of this
                  Section 3.14(f) after a Withdrawal Notice is delivered shall
                  have the effect of limiting or denying any such rights granted
                  hereunder to a Withdrawing Member.

            (g)   Notwithstanding any other provision of this Section 3.14, a
                  Withdrawing Member shall be entitled to receive each financial
                  report prepared for and distributed to the non-Withdrawing
                  Members as required by Section 11.02 hereof until such time as
                  the Withdrawing Member's Capital Contributions have been
                  returned to such Withdrawing Member.

            (h)   The non-Withdrawing Members shall have the right but not the
                  obligation for a period of sixty (60) days from the date of
                  the Withdrawal Notice to purchase the Membership Interest of a
                  Withdrawing Member for an amount equal to the aggregate
                  Capital Contributions of the Withdrawing Member and such
                  Membership Interest shall be sold free and clear of all
                  claims, liens and encumbrances. If more than one
                  non-Withdrawing Member elects to purchase the Membership
                  Interest of the Withdrawing Member, such Members shall be
                  entitled to purchase such Interest on a pro rata basis or in
                  such other manner as they mutually agree.

      3.15 Lack of Authority. Except as expressly provided for in these
Regulations or with Unanimous Approval, no Member acting in its capacity as a
Member shall have the authority or


                                       24
<PAGE>   33
power to act alone for or on behalf of the Company, to do any act that would be
binding on the Company, or to incur any expenditures on behalf of the Company.

                                  ARTICLE 4.

                             CAPITAL CONTRIBUTIONS

      4.01 Initial and Scheduled Capital Contributions. Contemporaneously with
the execution of these Regulations, each Member shall make the Initial Capital
Contribution for that Member as designated on Exhibit A hereto. Each Member also
agrees to make all future Capital Contributions necessary to permit the Company
to make capital contributions to the Partnership required to be made by the
Company as General Partner of the Partnership as determined from time to time by
the Management Committee to fund expenditures approved in any Budget for the
Partnership (the "Scheduled Capital Contributions") as well as any Additional
Capital Contributions required to be made pursuant to these Regulations. No
interest shall be paid on any Capital Contribution made by any Member.

      4.02 Additional Capital Contributions. Without creating any rights in
favor of any third party, each Member shall contribute to the Company, in cash,
on or before the date specified as hereinafter described, its Membership
Interest of (a) all monies required to cover all Additional Capital
Contributions (as such term is defined in the Partnership Agreement) that may be
assessed against the Company pursuant to the Partnership Agreement and (b) all
monies required by the Budget or necessary in the judgment of the Members to
enable the Company to cause the assets of the Company to be properly operated
and maintained and to discharge its costs, expenses, obligations, and
liabilities. The chairman of the Management Committee shall notify each Member
of the need for Scheduled Capital Contributions or Capital Contributions
pursuant to this Section 4.02 when appropriate, which notice shall include a
statement in reasonable detail of the proposed uses of the Capital Contributions
and a date (which date may be not earlier than the fifteenth (15th) Business Day
following a Member's receipt of its notice) before which the Capital
Contributions must be made (the "Contribution Date").

      4.03 Failure to Contribute. If a Member fails to contribute all or any
portion of a Capital Contribution that the Member (the "Delinquent Member") is
required to make as provided in these Regulations and such failure continues for
sixty (60) days from the Contribution Date, then the Delinquent Member shall be
deemed to be a Withdrawing Member and shall be treated as a Withdrawing Member
pursuant to Section 3.14 hereof effective as of the end of such sixty (60) day
period; provided, however, a Delinquent Member shall not be entitled to (i) a
return of any Capital Contributions (and shall forfeit the same) and (ii) the
indemnification provided pursuant to Section 3.14(f) hereof. Throughout any
period during which a Member is a Delinquent Member, the delinquent Capital
Contribution, or any delinquent portion thereof, shall bear interest at a rate
per annum equal to the lesser of (x) the sum of the Prime Rate plus five percent
(5%) and (y) the maximum rate permitted by applicable law from the Contribution
Date until the date the Capital Contribution is received by the Company.


                                       25
<PAGE>   34
      4.04 Return of Contributions. Except as may be specifically provided in
these Regulations, a Member shall not be entitled to the return of any part of
its Capital Contributions or to be paid interest in respect of either its
Capital Account or its Capital Contributions. A Member shall not be required to
contribute or to lend any cash or property to the Company to enable the Company
to return any Member's Capital Contributions.

      4.05 Advances by Members. If the Company does not have sufficient cash to
pay its obligations, any Member(s) that may agree to do so may advance all or
part of the needed funds to or on behalf of the Company (provided the Member has
made its Capital Contribution). An advance described in this Section 4.05
constitutes a loan from the Member to the Company, bears interest at the General
Interest Rate from the date of the advance until the date of payment and is not
a Capital Contribution. Terms of any loan to the Company by a Member shall be
determined in accordance with the Interested Matters Voting Procedures.

      4.06 Capital Account. A Capital Account shall be established and
maintained for each Member.

      4.07 Capital Contributions for System Modifications. No Member shall have
any obligation to make Additional Capital Contributions requested for the
purpose of funding the costs of a System Modification unless the Member has
voted in favor of such System Modification. It is the intent of the Members that
the Members' Membership Interests shall be adjusted to reflect the Membership
Interest of each Member immediately after Additional Capital Contributions are
made relating to the costs of any System Modification. A Member that votes
against a System Modification shall not be permitted to make Capital
Contributions for such System Modification unless the Members voting in favor of
the System Modification unanimously consent to such contribution.

                                  ARTICLE 5.

                                  ALLOCATIONS

      5.01 Profits. After giving effect to the special allocations set forth in
Sections 5.03 and 5.04 hereof, Profits for any Allocation Year shall be
allocated as follows:

      (a) First, to each Member in an amount equal to the excess, if any, of (i)
the cumulative Losses allocated to such Member pursuant to Section 5.02(a)
hereof for all prior Allocation Years, over (ii) the cumulative Profits
allocated to such Member pursuant to this Section 5.01(a) for all prior
Allocation Years; and

      (b) The balance, if any, among the Members in accordance with their
Membership Interests.


                                       26
<PAGE>   35
      5.02 Losses. After giving effect to the special allocations set forth in
Sections 5.03 and 5.04 hereof, Losses for any Allocation Year shall be allocated
as follows:

      (a) First, among the Members in accordance with their Membership
Interests, provided that Losses shall not be allocated pursuant to this Section
5.02(a) to the extent such allocation would cause any Member to have an Adjusted
Capital Account Deficit at the end of such Allocation Year; and

      (b) The balance, if any, among the Members in accordance with their
positive Capital Account balances.

      5.03 Special Federal Income Tax Allocations. The following special
allocations shall be made in the following order:

      (a) Minimum Gain Chargeback. Except as otherwise provided in Section
1.704-2(f) of the Treasury Regulations, notwithstanding any other provisions of
this Article 5, if there is a net decrease in Company Minimum Gain during any
Allocation Year, each Member shall be specially allocated items of Company
income and gain for such Allocation Year (and, if necessary, subsequent
Allocation Years) in an amount equal to such Member's share of the net decrease
in Company Minimum Gain, determined in accordance with Treasury Regulations
Section 1.704-2(g). Allocations pursuant to the previous sentence shall be made
in proportion to the respective amounts required to be allocated to each Member
pursuant thereto. The items to be so allocated shall be determined in accordance
with Sections 1.704-2(f)(6) and 1.704-2(j)(2) of the Treasury Regulations. This
Section 5.03(a) is intended to comply with the minimum gain chargeback
requirement in Section 1.704-2(f) of the Treasury Regulations and shall be
interpreted consistently therewith.

      (b) Member Minimum Gain Chargeback. Except as otherwise provided in
Section 1.704-2(i)(4) of the Treasury Regulations, notwithstanding any other
provision of this Article 5, if there is a net decrease in Member Nonrecourse
Debt Minimum Gain attributable to a Member Nonrecourse Debt during any
Allocation Year, each Member which has a share of the Member Nonrecourse Debt
Minimum Gain attributable to such Member Nonrecourse Debt, determined in
accordance with Section 1.704-2(i)(5) of the Treasury Regulations, shall be
specially allocated items of Company income and gain for such Allocation Year
(and, if necessary, subsequent Allocation Years) in an amount equal to such
Member's share of the net decrease in Member Nonrecourse Debt, determined in
accordance with Treasury Regulations Section 1.704-2(i)(4). Allocations pursuant
to the previous sentence shall be made in proportion to the respective amounts
required to be allocated to each Member pursuant thereto. The items to be so
allocated shall be determined in accordance with Sections 1.704-2(i)(4) and
1.704-2(j)(2) of the Treasury Regulations. This Section 5.03(b) is intended to
comply with the minimum gain chargeback requirement in Section 1.704-2(i)(4) of
the Treasury Regulations and shall be interpreted consistently therewith.

      (c) Qualified Income Offset. In the event any Member unexpectedly receives
any adjustments, allocations or distributions described in Sections
1.704-1(b)(2)(ii)(d)(4),


                                       27
<PAGE>   36
1.704-1(b)(2)(ii)(d)(5) or 1.704-1(b)(2)(ii)(d)(6) of the Treasury Regulations,
items of Company income and gain shall be specially allocated to such Member in
an amount and manner sufficient to eliminate, to the extent required by the
Treasury Regulations, the Adjusted Capital Account Deficit of the Member as
quickly as possible, provided that an allocation pursuant to this Section
5.03(c) shall be made only if and to the extent that the Member would have an
Adjusted Capital Account Deficit after all other allocations provided for in
this Article 5 have been tentatively made as if this Section 5.03(c) were not in
these Regulations.

      (d) Nonrecourse Deductions. Nonrecourse Deductions for any Allocation Year
shall be specially allocated to the Members in proportion to their respective
Membership Interests.

      (e) Member Nonrecourse Deductions. Any Member Nonrecourse Deductions for
any Allocation Year shall be specially allocated to the Member(s) that bear the
economic risk of loss with respect to the Member Nonrecourse Debt to which such
Member Nonrecourse Deductions are attributable in accordance with Treasury
Regulations Section 1.704-2(i)(1).

      (f) Section 754 Adjustments. To the extent an adjustment to the adjusted
tax basis of any Company asset, pursuant to Code Section 734(b) or Code Section
743(b) is required, pursuant to Treasury Regulations Section
1.704-1(b)(2)(iv)(m)(2) or 1.704-1(b)(2)(iv)(m)(4), to be taken into account in
determining Capital Accounts as the result of a distribution to a Member in
complete liquidation of such Member's Membership Interest, the amount of such
adjustment to Capital Accounts shall be treated as an item of gain (if the
adjustment increases the basis of the asset) or loss (if the adjustment
decreases such basis) and such gain or loss shall be specially allocated to the
Members in accordance with their Membership Interests in the event Treasury
Regulations Section 1.704-1(b)(2)(iv)(m)(2) applies, or to the Member to which
such distribution was made in the event Treasury Regulations Section
1.704-1(b)(2)(iv)(m)(4) applies.

      5.04 Curative Allocations. The allocations set forth in Sections 5.03(a),
5.03(b), 5.03(c), 5.03(d), 5.03(e), 5.03(f) and 5.05 hereof (the "Regulatory
Allocations") are intended to comply with certain requirements of the Treasury
Regulations. It is the intent of the Members that, to the extent possible, all
Regulatory Allocations shall be offset either with other Regulatory Allocations
or with special allocations of other items of Company income, gain, loss or
deduction pursuant to this Section 5.04. Therefore, notwithstanding any other
provision of this Article 5 (other than the Regulatory Allocations), the Company
shall make such offsetting special allocations of Company income, gain, loss or
deduction in whatever manner it determines appropriate so that, after such
offsetting allocations are made, each Member's Capital Account balance is, to
the extent possible, equal to the Capital Account balance such Member would have
had if the Regulatory Allocations were not part of these Regulations and all
Company items were allocated pursuant to Sections 5.01, 5.02, and 5.03(g)
hereof.

      5.05 Loss Limitation. Losses allocated pursuant to Section 5.02 hereof
shall not exceed the maximum amount of Losses that can be allocated without
causing any Member to have an Adjusted Capital Account Deficit at the end of any
Allocation Year. In the event some but not all


                                       28
<PAGE>   37
of the Members would have Adjusted Capital Account Deficits as a consequence of
an allocation of Losses pursuant to Section 5.02 hereof, the limitation set
forth in this Section 5.05 shall be applied on a Member-by-Member basis and
Losses not allocable to any Member as a result of such limitation shall be
allocated to the other Members in accordance with the positive balances in such
Member's Capital Accounts so as to allocate the maximum permissible Losses to
each Member under Section 1.704-1(b)(2)(ii)(d) of the Treasury Regulations.

      5.06  Other Allocation Rules.

      (a) For purposes of determining the Profits, Losses or any other items
allocable to any period, Profits, Losses and any such other items shall be
determined on a daily, monthly or other basis, as determined by the Members
using any permissible method under Code Section 706 and the Treasury Regulations
thereunder.

      (b) The Members are aware of the income tax consequences of the
allocations made by this Article 5 and hereby agree to be bound by the
provisions of this Article 5 in reporting their shares of Company income and
loss for income tax purposes.

      (c) Solely for purposes of determining a Member's proportionate share of
the "excess nonrecourse liabilities" of the Company within the meaning of the
Treasury Regulations Section 1.752-3(a)(3), the Members' interests in Company
profits shall be in proportion to their Membership Interests.

      To the extent permitted by Section 1.704-2(h)(3) of the Treasury
Regulations, the Members shall endeavor to treat distributions of Net Cash Flow
as having been made from the proceeds of a Nonrecourse Liability or a Member
Nonrecourse Debt only to the extent that such distributions would cause or
increase an Adjusted Capital Account Deficit for any Member.

      5.07  Contributed Property, Tax Allocations.

      (a) Code Section 704(c). In accordance with Code Section 704(c) and the
Treasury Regulations thereunder, income, gain, loss and deduction with respect
to any property contributed to the capital of the Company shall, solely for tax
purposes, be allocated among the Members so as to take account of any variation
between the adjusted basis of such property to the Company for federal income
tax purposes and its initial Gross Asset Value (computed in accordance with the
definition of Gross Asset Value) using an acceptable allocation method pursuant
to the Treasury Regulations under Section 704(c) as selected by the Members.

      (b) In the event the Gross Asset Value of any Company asset is adjusted
pursuant to subparagraph (ii) of the definition of Gross Asset Value, subsequent
allocations of income, gain, loss and deduction with respect to such asset shall
take account of any variation between the adjusted basis of such asset for
federal income tax purposes and its Gross Asset Value in the same manner as
under Code Section 704(c) and the Regulations thereunder.


                                       29
<PAGE>   38
      (c) Any elections or other decisions relating to such allocations shall be
made by the Members in any manner that reasonably reflects the purpose and
intention of these Regulations. Allocations pursuant to this Section 5.07 are
solely for purposes of federal, state, and local taxes and shall not affect or
in any way be taken into account in computing any Member's Capital Account or
share of Profits, Losses, other items or distributions pursuant to any provision
of these Regulations.

                                  ARTICLE 6.

                                 DISTRIBUTIONS

      6.01 Distributions. From time to time the Members shall determine in their
reasonable judgment to what extent (if any) the Company's cash on hand exceeds
its current and anticipated needs, including, without limitation, its operating
expenses, debt service, acquisitions and a reasonable contingency reserve. If
such an excess exists, the Members shall vote in accordance with Article 7
hereof to determine the amount, if any, and the timing of any distributions.
Except as provided in Section 3.14 hereof, all Distributions to the Members
shall be in accordance with their respective Membership Interests.

      6.02 Tax Amounts Withheld. All amounts withheld pursuant to the Code or
any provision of any state, local or foreign tax law with respect to any
payment, distribution or allocation to the Company or the Members shall be
treated as amounts paid or distributed, as the case may be, to the Members with
respect to which such amount was withheld pursuant to this Section 6.02 for all
purposes under these Regulations. The Company is authorized to withhold from
payments and distributions, or with respect to allocations to the Members, and
to pay over to any federal, state and local government or any foreign
government, any amounts required to be so withheld pursuant to the Code or any
provisions of any other federal, state or local law or any foreign law, and
shall allocate any such amounts to the Members with respect to which such amount
was withheld. Since withholding is imposed with respect to any foreign Member's
allocable share of the income subject to withholding, regardless of whether any
distributions are made to the foreign Member, any Member with Excess Withholding
Liability must remit that amount to the Company within ten (10) days of notice
from the Company thereof.

      6.03 Limitations on Distributions. The Company shall make no distributions
to the Members except (i) as provided in this Article 6 hereof, or (ii) as
otherwise agreed to by the Required Interest.


                                       30
<PAGE>   39
                                  ARTICLE 7.

                           MANAGEMENT OF THE COMPANY

      7.01 Management by the Members.

      (a) Subject to nonwaivable provisions of applicable law and the provisions
of these Regulations, the powers of the Company shall be exercised by or under
the authority of, and the business and affairs of the Company shall be managed
under the direction of, the Members which shall conduct, direct and exercise
control over all activities of the Company and shall have full power and
authority on behalf of the Company to manage and administer the business and
affairs of the Company and to do or cause to be done any and all acts deemed
necessary by it to be necessary or appropriate to conduct the business of the
Company. Except as provided to the contrary in Sections 7.01(b), (c) and (d)
below and as otherwise specifically provided in this Agreement, all decisions by
the Members shall be by Majority Approval.

      (b) The Members may not cause the Company to do or perform any acts
specified in Schedule 7.01(b) hereto without Super Majority Approval.

      (c) The Members may not cause the Company to do or perform any acts
specified in Schedule 7.01(c) hereto without Unanimous Approval.

      (d) When, with respect to any matter to be voted on by the Members, a
conflict of interest exists such that a conflicted Member elects not to
participate in such vote (or such conflicted Member is asked not to participate
in such vote by any two (2) other Members), the remaining non-conflicted Members
shall proceed with the vote as if they collectively owned, in the aggregate, one
hundred percent (100%) of the Membership Interests. In such case, the quantity
of Membership Interests and number of votes required to approve the matter under
consideration, as specified in this Section 7.01, shall be calculated based only
on the Members and Membership Interests actually voting. The procedures
described in this subsection 7.01(d) shall be the "Interested Matters Voting
Procedures". Without limiting the actions which are subject to the Interested
Matters Voting Procedures, as described in this subsection 7.01(d), the actions
set forth in Schedule 7.01(d) shall be subject to the Interested Matters Voting
Procedures.

      7.02  Actions by Member Committees; Delegation of Authority and Duties.

      (a) In managing the business affairs of the Company and exercising its
powers, the Members shall act (i) collectively through meetings and written
consents pursuant to Article 8 hereof, (ii) through committees pursuant to
Sections 7.02(b) and (d) hereof and (iii) through a Member, officer or other
Person to whom authority and duties have been delegated pursuant to Section
7.02(c) hereof.


                                       31
<PAGE>   40
      (b) The Members may, from time to time, with the approval of the Required
Interest designate by resolutions to such effect one or more committees, each of
which shall be comprised of one or more of the Members. Any such committee, to
the extent provided in such resolution or Certificate or these Regulations and
subject to the approval of the Required Interest, shall have and may exercise
all of the authority of the Members, subject to the limitations set forth in the
Act. At every meeting of any such committee, the presence of a majority of all
the members thereof shall constitute a quorum, and the affirmative vote of a
majority of the members present shall be necessary for the adoption of any
resolution. The Members may dissolve any committee at any time, unless otherwise
provided in the Certificate or these Regulations.

      (c) The Members may, from time to time, with the approval of the Required
Interest delegate to one or more Members, designees of such Members, employees
of the Company or any Person such authority and duties as the Members may deem
advisable. In addition, the Member with the approval of a Required Interest, may
assign titles (including, without limitation, president, vice president,
secretary, assistant secretary, treasurer and assistant treasurer) to any such
Member, designee of such Members, employees of the Company or any Person. Any
number of titles may be held by such a Person designated by the Members. Any
delegation pursuant to this Section 7.02(c) may be revoked at any time by the
vote of the Required Interest.

      (d) The Members hereby establish a management committee (the "Management
Committee") whose Members shall be comprised of one (1) representative
designated by each Member. The initial Management Committee Members shall
consist of the individuals set forth on Exhibit C hereto. The Management
Committee shall be vested with all powers and duties to manage the affairs of
the Company to the full extent and in the same manner as the Members are
permitted by these Regulations, the Act or the DGCL. Any Member may change its
designated representative on the Management Committee by giving notice to the
Company and the other Members as provided in Section 15.04 hereof. All voting by
the Management Committee shall be undertaken on the same basis as voting by the
Members with each Member of the Management Committee being able to vote the
Membership Interest of the Member that such Management Committee Member
represents. All meetings of the Management Committee shall be held in accordance
with the provisions of Article 8 hereof applicable to the meetings of the
Members. The Management Committee shall have a chairman who shall serve for a
term of two (2) years. The chairmanship shall rotate every two (2) years to the
representative designated by the Member in the following order:

            (i)   Columbia (Initial Chairman)

            (ii)  TransCanada

            (iii) Westcoast

            (iv)  MCN

      7.03  Conflicts of Interest and Affiliate Transactions.

            (a) The Members and their Affiliates agree not to participate in the
development of or invest in, directly or indirectly as an equity participant,
any other greenfield project or venture


                                       32
<PAGE>   41
into the U.S. Northeast which, if developed, would offer natural gas
transportation services in competition with the Millennium Pipeline System until
December 31, 1998, unless a Member discloses such interest in a potentially
competing project and receives written consent to participate from all of the
other Members. The Members and their Affiliates shall be free to pursue any
complimentary or non-competing ventures without the participation of any other
Member. The Members hereby agree that Columbia's service on its existing
transmission system and Columbia's market expansion project authorized pursuant
to FERC Docket No. CP96-213 will not be deemed as a violation of its covenant
not to compete. The Members further acknowledge that Westcoast (or an Affiliate)
is involved in the Maritimes and Northeast Pipeline Project, MCN (or an
Affiliate) is involved in the Portland Natural Gas Transmission Project, and
TransCanada (or an Affiliate) is involved in the TransMaritime Gas Transmission
Project, Iroquois Gas Transmission and the Portland Natural Gas Transmission
Project, as well as the TransCanada PipeLines, Limited "Canadian Mainline" and
the Members agree that participation or ownership in any of the aforementioned
projects or pipelines, or any contemplated or future expansions thereof, will
not be a violation of the covenant not to compete.

            (b) From and after December 31, 1998 (or such other date as may be
determined by Unanimous Consent), each Member and its Affiliates at any time and
from time to time may engage in and possess interests in other business ventures
of any and every type and description, independently or with others, including
ones in competition with the Company, with no obligation to offer to the
Company, any other Member or any of their Affiliates the right to participate
therein. Neither the Company nor any of the other Members shall have any rights
by virtue of this Agreement in and to such independent business ventures or to
the income or profits derived therefrom.

            (c) The Company may not engage in an Affiliate Transaction or cause
the Partnership to engage in an Affiliate Transaction unless (i) the terms of
each Affiliate Transaction are no less favorable than those the Company or the
Partnership could obtain from unrelated third parties and (ii) each Affiliate
Transaction involving an amount in excess of US$10,000 in the aggregate has been
approved by the Required Interest.

      7.04  Officers.

      (a) Qualifications, Duties and Term of Office. The Members may, from time
to time and with the approval of a Required Interest, designate one or more
Persons to be officers of the Company. No officer need be a resident of the
State of Delaware or a Member. Any officers so designated shall have such
authority and perform such duties as the Members may, from time to time,
delegate to them. The Members may assign titles to particular officers. Unless
the Members decide otherwise, if the title is one commonly used for officers of
a business corporation formed under the DGCL, the assignment of such title shall
constitute the delegation to such officer of the authority and duties that are
normally associated with that office, subject to (i) specific delegation of
authority and duties made to such officer by the Members pursuant to the third
sentence of this Section 7.04(a), or (ii) any delegation of authority and duties
made to one or more Members pursuant to Section 7.02(a) hereof. Each officer
shall hold office until his successor shall be duly designated


                                       33
<PAGE>   42
and shall qualify or until his death or until he shall resign or shall have been
removed in the manner hereinafter provided. Any number of offices may be held by
the same Person. The salaries or other compensation, if any, of the officers and
agents of the Company shall be fixed from time to time by the Members.

      (b) Resignation; Removal. Any officer may resign as such at any time. Such
resignation shall be made in writing and shall take effect at the time specified
therein, or if no time be specified, at the time of its receipt by the Members.
The acceptance of a resignation shall not be necessary to make it effective,
unless expressly so provided in the resignation. Any officer may be removed as
such, either with or without cause, by the Required Interest whenever in their
judgment the best interests of the Company will be served thereby; provided,
however, that such removal shall be without prejudice to the contract rights, if
any, of the Person so removed. Designation of any officer shall not itself
create contract rights. Any vacancy occurring in any office of the Company may
be filled by the Members.

      (c) Officers. The powers and duties of the officers with the following
titles shall be as follows:

            (i) Chairman. The chairman, if one is elected, shall preside at all
      meetings of the Members, and shall have such other powers and duties as
      may from time to time be prescribed by the Members.

            (ii) Chief Executive Officer. The chief executive officer, if one is
      elected, shall be either the chairman or the president of the Company, as
      determined from time to time by duly adopted resolution of the Members.
      The chief executive officer, if one is elected, shall preside at all
      meetings of the Members if there is no chairman, shall have and may
      exercise the powers of the president of the Company, and shall have such
      other powers and duties as may from time to time be prescribed by the
      Members.

            (iii) President. The president shall, subject to the direction of
      Members, the Management Committee and, if any, the chairman and/or chief
      executive officer of the Company, have general executive charge,
      management and control of the Property and operations of the Company in
      the ordinary course of its business with all such powers with respect to
      such responsibilities including the powers of a general manager; the
      president shall preside at all meetings of the Members if there is no
      chairman or the chairman is absent or disabled from acting; the president
      shall be ex-officio a member of all standing committees; subject to
      approval by the Members, the president may agree upon and execute all
      division and transfer orders, bonds, contracts and other obligations in
      the name of the Company; the president may sign all certificates
      representing securities of the Company; and the president shall see that
      all orders and resolutions of the Members are carried into effect. The
      president shall have such other powers and duties as may from time to time
      be prescribed by the Members.


                                       34
<PAGE>   43
            (iv) Chief Operating Officer. The chief operating officer, if one is
      elected, shall be the same Person as the president of the Company and
      shall have such other powers and duties as may from time to time be
      prescribed by the Members.

            (v) Vice Presidents. Each vice president shall have such powers and
      duties as may from time to time be prescribed by duly adopted resolution
      of the Members or by the president. The vice presidents in the order of
      their seniority, unless otherwise determined by the Members, shall, if the
      president is absent or disabled from acting, have the authority, exercise
      the powers and perform the duties of the president during the president's
      absence or inability to act.

            (vi) Chief Financial Officer and/or Treasurer. If the Members
      determine to elect both a chief financial officer and a treasurer, both
      offices shall be held by the same Person. The chief financial officer, if
      one is elected, and/or the treasurer, if one is elected, shall have
      custody of all the funds and securities of the Company which come into his
      hands. When necessary or proper, he may, on behalf of the Company, endorse
      for collection checks, notes and other obligations, and shall deposit the
      same to the credit of the Company in such bank or banks or depositories as
      shall be designated in the manner prescribed by the Members; and he may
      sign all receipts and vouchers for payments made to the Company, either
      alone or jointly with such other office as is designated by the Members.
      Whenever required by the Members, he shall render a statement of his cash
      account; he shall enter or cause to be entered regularly in the books of
      the Company to be kept by him for that purpose full and accurate accounts
      of all moneys received and paid out on account of the Company; he shall
      perform all acts incident to the position of treasurer subject to the
      control of the Members, and he shall, if required by the Members, give
      such bond for the faithful discharge of his duties in such form as the
      Members may require. The chief financial officer and/or the treasurer
      shall have such other powers and duties as may from time to time be
      prescribed by the Members or by the president.

            (vii) Assistant Treasurers. Each assistant treasurer, if any is
      elected, shall have the usual powers and duties pertaining to his office,
      together with such other powers and duties as may from time to time be
      prescribed by the Members or by the president. The assistant treasurers in
      the order of their seniority, unless otherwise determined by the Members,
      shall, if the chief financial officer and/or treasurer is absent or
      disabled from acting, have the authority, exercise the powers and perform
      the duties of the chief financial officer and/or treasurer during that
      officer's absence or inability to act.

            (viii) Secretary. The secretary shall keep the minutes of all
      meetings of the Members in books provided for that purpose or in any other
      form capable of being converted into written form within a reasonable
      time; he shall attend to the giving and serving of all notices; he may
      sign with the president in the name of the Company all contracts of the
      Company and affix the seal of the Company thereto; he shall have charge of
      any such other books and papers as the Members may direct, all of which
      shall at all reasonable times be


                                       35
<PAGE>   44
      open to the inspection of any Member upon application at the office of the
      Company during business hours; and he shall in general perform all duties
      incident to the office of secretary, subject to the control of the
      Members.

            (ix) Assistant Secretaries. Each assistant secretary shall have the
      powers and duties pertaining to his office, together with such other
      powers and duties as may from time to time be prescribed by duly adopted
      resolution of the Members or by the president. The assistant secretaries
      in the order of their seniority, unless otherwise determined by the
      Members, shall, if the secretary is absent or disabled from acting, have
      the authority, exercise the powers and perform the duties of the secretary
      during the secretary's absence or inability to act.

      (d) Initial Officers. Those individuals listed on Exhibit D, shall be, and
they hereby are, appointed by the Members as the officers of the Company as
reflected on Exhibit D with those duties generally assigned such offices until
their resignation or removal in accordance with these Regulations. Subject to
the approval of the Members, the chairman shall identify the other officers to
serve in those offices identified in these Regulations or created by the
Members.

      7.05 Insurance. During the term of these Regulations, the Company shall at
all times carry and maintain in full force and effect such insurance as the
Members deem reasonably necessary for the operation of the business of the
Company, including but not limited to officer and director or equivalent
liability coverage pursuant to Section 9.06 hereof, if appropriate. The premiums
for any such insurance coverage shall be an expense borne by the Company. The
Members shall be named as additional insureds under such policies in such
business or individual capacities as may be deemed appropriate by the Company to
effectuate the intent of this provision.

                                  ARTICLE 8.

                              MEETINGS OF MEMBERS

      8.01 Meetings.

      (a) With respect to any matter (other than a matter for which the
affirmative vote of the holders of a specified portion of the Membership
Interests of all Members entitled to vote is required by the Act), the
affirmative vote of the Required Interest at a meeting of the Members shall be
the act of the Members. A Member who is present at a meeting of the Members at
which any action on any Company matter is taken shall be presumed to have
assented to the action unless such Member's dissent or election to abstain shall
be entered in the minutes of the meeting or unless he shall file his written
dissent to such action or abstention with respect to the matter being voted upon
with the Person acting as secretary of the meeting before the adjournment
thereof or shall deliver such dissent or notice of abstention to the Company
immediately after the adjournment of the meeting. Such right to dissent or
abstain from voting shall not apply to a Member that voted in favor of such
action. For voting purposes, if on any action voted on there are Abstaining
Members, the Abstaining Members


                                       36
<PAGE>   45
shall be treated as if a conflict exists with regard to the Abstaining Members
and the vote shall be determined in accordance with the Interested Matters
Voting Procedures.

      (b) All meetings of the Members shall be held at the principal place of
business of the Company or at such other place as shall be specified or fixed in
the notices or waivers of notice thereof; provided that any or all Members may
participate in any such meeting by means of conference telephone or similar
communications equipment pursuant to Section 8.05 hereof.

      (c) Notwithstanding any contrary provisions of the Certificate or these
Regulations, the chairman of the meeting or the holders of the Required Interest
shall have the power to adjourn such meeting from time to time, without any
notice other than announcement at the meeting of the time and place at which
such adjourned meeting shall be reconvened. If such meeting is adjourned by the
Members, such time and place shall be determined by a vote of the holders of the
Required Interest. Upon the resumption of such adjourned meeting, any business
may be transacted that might have been transacted at the meeting as originally
called.

      (d) An annual meeting of the Members shall be held at such place, within
or without the State of Delaware, on such date and at such time as the Members
shall fix and set forth in the notice of the meeting, which date shall be within
twelve (12) months subsequent to the Effective Date or the last annual meeting
of Members, whichever most recently occurred.

      (e) Special meetings of the Members for any proper purpose or purposes may
be called at any time by one or more Members holding at least ten percent (10%)
of the Membership Interests of all Members. If not otherwise stated in or fixed
in accordance with the remaining provisions hereof, the date any Member first
signs the notice of a meeting shall constitute the record date for determining
which Members are entitled to call a special meeting. Only business within the
purpose or purposes described in the notice (or waiver thereof) required by
these Regulations may be conducted at a special meeting of the Members.

      (f) Written or printed notice stating the place, day and hour of the
meeting, and in the case of a special meeting, the purpose or purposes for which
the meeting is called, shall be delivered not less than ten (10) nor more than
sixty (60) days before the date of the meeting pursuant to Section 15.04, to
each Member entitled to vote at such meeting.

      (g) The date on which notice of a meeting of the Members is faxed or
mailed, or the date on which the resolution of the Members declaring a
distribution is adopted, as the case may be, shall be the record date for the
determination of the Members entitled to notice or to vote at such meeting,
including any adjournment thereof or the Members entitled to receive such
distributions.

      (h) Attendance of a Member at a meeting shall constitute a waiver of
notice of such meeting, except where a Member attends a meeting for the express
purpose of objecting to the transaction of any business on the ground that the
meeting is not lawfully called or convened.


                                       37
<PAGE>   46
      (i) The right of Members to cumulative voting in the election of officers
of the Company is expressly prohibited.

      8.02 Voting List. At any time that the Company has in excess of four (4)
Members, the chairman of the Management Committee or other designated Member
shall make, at least ten (10) days before each meeting of Members, a complete
list of the Members entitled to vote at such meeting or any adjournment thereof,
arranged in alphabetical order, with the address of and the Membership Interest
held by each, which list, for a period of ten (10) days prior to such meeting,
shall be kept on file at the registered office or the principal place of
business of the Company and shall be subject to inspection by any Member at any
time on a Business Day during usual business hours. Such list shall also be
produced and kept open at the time and place of the meeting and shall be subject
to the inspection of any Member during the whole time of the meeting. The
original membership records shall be prima facie evidence as to who are the
Members entitled to examine such voting list or records or to vote at any
meeting of Members. Failure to comply with the requirements of this Section 8.02
shall not affect the validity of any action taken at the meeting.

      8.03 Proxies. A Member may vote either in person or by proxy executed in
writing by the Member. A telegram, telex, cablegram or similar transmission by
the Member, or a photographic, photostatic, facsimile or similar reproduction of
a writing executed by the Member shall be treated as an execution in writing for
purposes of this Section 8.03. Proxies for use at any meeting of Members or in
connection with the taking of any action by written consent shall be delivered
to Members, before or at the time of the meeting or execution of the written
consent, as the case may be. All proxies shall be received and taken charge of
and all ballots shall be received and canvassed by the Members, who shall decide
all questions touching upon the qualification of voters, the validity of the
proxies and the acceptance or the rejection of votes, unless an inspector or
inspectors shall have been appointed by the chairman of the meeting in which
event such inspector or inspectors shall decide all such questions. No proxy
shall be valid after eleven (11) months from the date of its execution unless
the proxy form conspicuously states that the proxy is irrevocable and the proxy
is coupled with any interest. If a proxy designates more than two (2) Persons to
act as proxies, unless that instrument shall provide to the contrary, a majority
of such Persons present at any meeting at which their powers thereunder are to
be exercised shall have and may exercise all the powers of voting or giving
consents thereby conferred, or, if only one (1) be present, such powers may be
exercised by that one; or, if an even number attend and a majority do not agree
on any particular issue, the Company shall not be required to recognize such
proxy with respect to such issue if such proxy does not specify how the
Membership Interest that is the subject of such proxy is to be voted with
respect to such issue.

      8.04 Conduct of Meetings. All meetings of the Members shall be presided
over by the chairman of the meeting, who shall be a Member (or representative
thereof) designated by a majority of the Members. The chairman of any meeting of
the Members shall determine the order of business and the procedure at the
meeting including such regulation of the manner of voting and the conduct of
discussion as seem to the chairman in order.


                                       38
<PAGE>   47
      8.05  Action by Written Consent or Telephone Conference.

      (a) Any action required or permitted to be taken at any annual or special
meeting of the Members may be taken without a meeting, without prior notice and
without a vote, if a consent or consents in writing, setting forth the action so
taken, shall be signed and dated by each of the Members. No written consent
shall be effective to take the action that is the subject to the consent unless,
within sixty (60) days after the date of the earliest dated consent delivered to
the Company in the manner required by this Section 8.05(a), a consent or
consents signed and dated by each of the Members are delivered to the Company by
delivery to its registered office, its principal place of business, or the
Members. Delivery shall be by hand or certified or registered mail, return
receipt requested. Delivery to the Company's principal place of business shall
be addressed to the Members. A telegram, telex, cablegram or similar
transmission by a Member shall be regarded as signed by the Member for purposes
of this Section.

      (b) The record date for determining Members entitled to consent to an
action in writing without a meeting shall be the first date on which a signed
written consent setting forth the action taken or proposed to be taken is
delivered to the Company by delivery to its registered office, its principal
place of business or a Member. Delivery shall be by hand or by certified or
registered mail, return receipt requested. Delivery to the Company's principal
place of business shall be addressed to the Members.

      (c) If any action by Members is taken by written consent, certificates or
documents filed with the Secretary of State of Delaware as a result of the
taking of the action shall state, in lieu of any statement required by the Act
concerning any vote of Members, that written consent has been given in
accordance with the provisions of the Act and that any written notice required
by the Act has been given.

      (d) Members may participate in and hold a meeting by means of telephone
conference or similar communications equipment by means of which all Persons
participating in the meeting can hear each other, and participation in such
meeting shall constitute attendance and presence in person at such meeting,
except when a Person who participates in the meeting objects to the transaction
of any business on the ground that the meeting is not lawfully called or
convened.

                                  ARTICLE 9.

                                INDEMNIFICATION

      9.01  Right to Indemnification. Subject to the limitations and conditions
as provided in this Article 9, each Person who was or is made a party to or is
threatened to be made a party to or is involved in any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative,
arbitrative or investigative (hereinafter an "Action"), or any appeal of such an
Action or any inquiry or investigation that could lead to such an Action, by
reason of the fact that he, or a Person of whom he is the legal representative,
is or was a Member of the Company, while a Member


                                       39
<PAGE>   48
of the Company is or was serving at the request of the Company as a director,
officer, partner, venturer, proprietor, trustee, employee, agent or similar
functionary of another foreign or domestic limited liability company,
corporation, partnership, joint venture, sole proprietorship, trust, employee
benefit plan or other enterprise shall be indemnified by the Company to the
fullest extent permitted by the Act, as the same exists or may hereafter be
amended (but, in the case of any such amendment, only to the extent that such
amendment permits the Company to provide broader indemnification rights than
said law permitted the Company to provide prior to such amendment) against
judgments, penalties (including excise and similar taxes and punitive damages),
fines, settlements and reasonable expenses (including, without limitation,
attorneys' fees) actually incurred by such Person in connection with such Action
and the indemnification under this Article 9 shall continue as to a Person who
has ceased to serve in the capacity which initially entitled such Person to
indemnity hereunder. The rights granted pursuant to this Article 9 shall be
deemed contract rights, and no amendment, modification or repeal of this Article
9 shall have the effect of limiting or denying any such rights with respect to
actions taken or Actions arising prior to any such amendment, modification or
repeal. It is expressly acknowledged that the indemnification provided for in
this Article 9 could involve indemnification for negligence or under theories of
strict liability.

      9.02 Advance Payment. The right to indemnification conferred in this
Article 9 shall include the right to be paid or reimbursed by the Company for
the reasonable expenses incurred by a Person of the type entitled to be
indemnified under Section 9.01 who was, is or is threatened to be made a named
defendant or respondent in an Action in advance of the final disposition of the
Action and without any determination as to the Person's ultimate entitlement to
indemnification; provided, however, that the payment of such expenses incurred
by any such Person in advance of the final disposition of an Action shall be
made only upon delivery to the Company of a written affirmation by such Person
of its good-faith belief that it has met the standard of conduct necessary for
indemnification under this Article 9 and a written undertaking, by or on behalf
of such Person, to repay all amounts so advanced if it shall ultimately be
determined that such indemnified Person is not entitled to be indemnified under
this Article 9 or otherwise.

      9.03 Indemnification of Officers, Employees and Agents. The Company, by
adoption of a resolution of the Members, may indemnify and advance expenses to
any officer, employee or agent of the Company to the same extent and subject to
the conditions under which it may indemnify and advance expenses to a Person
under this Article 9, and the Company may indemnify and advance expenses to
Persons who are not or were not officers, employees or agents of the Company but
who are or were serving at the request of the Company as director, officer,
partner, venturer, proprietor, trustee, employee, agent or similar functionary
of another foreign or domestic limited liability company, corporation,
partnership, joint venture, sole proprietorship, trust, employee benefit plan or
other enterprise against any liability asserted against him and incurred by him
in such a capacity or arising out of his status as such a Person to the same
extent that it may indemnify and advance expenses to officers under this Article
9.

      9.04 Appearance of Witness. Notwithstanding any other provision of this
Article 9, the Company may pay or reimburse expenses incurred by a Member,
officer or other Person in


                                       40
<PAGE>   49
connection with his appearance as a witness or other participation in an Action
at a time when he is not a named defendant or respondent in the Action.

      9.05 Nonexclusivity of Rights. The right to indemnification and the
advancement and payment of expenses conferred in this Article 9 shall not be
exclusive of any other right which a Member, officer or other Person indemnified
pursuant to Section 9.03 may have or hereinafter acquire under any law (common
or statutory), provision of the Certificate or these Regulations, agreement,
vote of Members, or otherwise.

      9.06 Insurance. The Company may purchase and maintain insurance, at its
expense, to protect itself and any Person who is or was serving as an officer,
employee or agent of the Company or is or was serving at the request of the
Company as a manager, director, officer, partner, venturer, proprietor, trustee,
employee, agent or similar functionary of another foreign or domestic limited
liability company, corporation, partnership, joint venture, sole proprietorship,
trust, employee benefit plan or other enterprise against any expense, liability
or loss, whether or not the Company would have the power to indemnify such
Person against such expense, liability or loss under this Article 9.

      9.07 Member Notification. To the extent required by law, any
indemnification of or advance of expenses to a Member, officer or other Person
in accordance with this Article 9 shall be reported in writing to the Members
with or before the notice or waiver of notice of the next Members' meeting or
with or before the next submission to Members of a consent to action without a
meeting and, in any case, within the twelve (12) month period immediately
following the date of the indemnification or advance.

      9.08 Saving Clause. If this Article 9 or any portion hereof shall be
invalidated on any ground by any court of competent jurisdiction, then the
Company shall nevertheless indemnify and hold harmless each Member, officer or
any other Person indemnified pursuant to this Article 9 as to costs, charges and
expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement with respect to any action, suit or proceeding, whether civil,
criminal, administrative or investigative to the full extent permitted by any
applicable portion of this Article 9 that shall not have been invalidated and to
the fullest extent permitted by applicable law.

                                  ARTICLE 10.

                                     TAXES

      10.01 Tax Returns. The Members shall cause to be prepared and filed all
necessary federal and state tax returns for the Company, including making the
elections described in Section 10.02 hereof. Each Member shall furnish to the
Company all pertinent information in its possession relating to Company
operations that is necessary to enable the Company's tax returns to be timely
prepared and filed.


                                       41
<PAGE>   50
      10.02 Tax Elections. The Company shall make the following elections on the
appropriate tax returns:

      (a) to adopt the calendar or such other fiscal year as elected by the
Partnership as the Company's fiscal year;

      (b) to adopt the accrual method of accounting and to keep the Company's
tax records in accordance with applicable tax accounting principles,
consistently applied except as (i) set forth herein or (ii) otherwise determined
by the Members;

      (c) if a distribution of Company property as described in Section 734 of
the Code occurs or if a transfer of a Membership Interest as described in
Section 743 of the Code occurs, on written request of any Member, to elect,
pursuant to Section 754 of the Code, to adjust the basis of Company properties;

      (d) to elect to amortize the organizational expenses of the Company and
the startup expenditures of the Company under Section 195 of the Code ratably
over a period of sixty (60) months as permitted by Section 709(b) of the Code;

      (e) any other election the Members may deem appropriate and in the best
interests of the Members;

      (f) neither the Company nor any Member may make an election for the
Company to be excluded from the application of the provisions of subchapter K of
chapter I of subtitle A of the Code or any similar provisions of applicable
state law, and no provision of these Regulations (including, without limitation,
Section 2.08) shall be construed to sanction or approve such an election; and

      (g) the Company is intended to be classified as a partnership for federal
and state income tax purposes; no election shall be made by the Company or any
Member to classify the Company as other than a partnership pursuant to
regulations issued under Code Section 7701, or any similar provision of any
state law.

      10.03 Tax Matters Partner. Columbia shall be designated as the "tax
matters partner" of the Company pursuant to Section 6231(a)(7) of the Code and
shall serve in such capacity until its resignation or removal by the Members.
Upon its resignation or removal, the Members shall designate one Member to be
the "tax matters partner." Any Member which is designated as "tax matters
partner" shall take such action as may be necessary to cause each other Member
to become a "notice partner" within the meaning of Section 6223 of the Code. Any
Member which is designated as "tax matters partner" shall inform each other
Member of all significant matters that may come to its attention in its capacity
as "tax matters partner" by giving notice thereof on or before the fifth (5th)
Business Day after becoming aware thereof and, within that time, shall forward
to each other Member copies of all significant written communications it may
receive in that capacity. Any


                                       42
<PAGE>   51
Member which is designated as "tax matters partner" may not take any action
contemplated by Sections 6222 through 6232 of the Code without the consent of a
Required Interest, but this sentence does not authorize the Member to take any
action left to the determination of an individual Member under Sections 6222
through 6232 of the Code.

      10.04 Tax Reporting Information. The Company shall use its best efforts to
furnish the Members a report within one hundred twenty (120) days after the
close of the Company's fiscal year containing all tax reporting information
reasonably necessary for federal and applicable state and local income tax
purposes.

                                  ARTICLE 11.

                  BOOKS, RECORDS, REPORTS, AND BANK ACCOUNTS

      11.01 Maintenance of Books.

      (a) The Company shall keep books and records of accounts and shall keep
minutes of the proceedings of its Members and each committee of the Members. The
books of account for the Company shall be maintained on the accrual basis in
accordance with Required Accounting Practices, consistently applied, and the
terms of these Regulations. Notwithstanding the foregoing, the Capital Accounts
of the Members shall also be maintained in accordance with the definition of
Capital Accounts. The calendar year shall be the fiscal year of the Company
unless otherwise decided by the Members.

      (b) The Members and their agents may, at their own cost and expense,
examine, audit and obtain copies of the books, records and accounts of the
Company, including federal, state, and local income tax returns for each year as
and when they become available, inspect its properties, or otherwise make
reasonable inquiry as to Company affairs. Any such inspections shall be
conducted during the normal business hours of the Company.

      11.02 Reports. On or before the ninetieth (90th) day following the end of
each fiscal year, the Members shall cause the Company to furnish each Member
with a balance sheet, an income statement, a statement of changes in Members'
Capital Accounts and a statement of cash flows and accompanying independent
auditors report for, or as of the end of, that year, all of which shall be
prepared in accordance with Required Accounting Practices, consistently applied.
On or before the forty-fifth (45th) day following the end of each calendar
quarter, the Members shall cause the Company to furnish each Member with a
balance sheet, an income statement, a statement of changes in Members' Capital
Accounts, and a statement of cash flows for, or as of the end of, such calendar
quarter, all of which shall be prepared in accordance with Required Accounting
Practices, consistently applied. The Members shall also cause the Company to
furnish such other reports as reasonably requested by the Members.


                                       43
<PAGE>   52
      11.03 Accounts. The Members shall establish and maintain one or more
separate bank and investment accounts and arrangements for Company funds in the
Company name with financial institutions and firms that the Members shall from
time to time determine. The Members shall not commingle the Company's funds with
the funds of any Member; Company funds may, however, be invested in a manner the
same as or similar to any Member's investment of its funds or investments by its
Affiliates.

                                  ARTICLE 12.

                            BANKRUPTCY OF A MEMBER

      12.01 Bankrupt Members. Subject to any Member Agreement and Section
13.01(d) hereof, if any Member becomes a Bankrupt Member, the Company shall have
the option, exercisable by notice from the Members to the Bankrupt Member (or
its representative) at any time within thirty (30) days after receipt of notice
of the occurrence of the event causing it to become a Bankrupt Member, to buy,
and on the exercise of this option the Bankrupt Member or its representative
shall sell, its Membership Interest. The purchase price shall be an amount equal
to the fair market value thereof determined by agreement by the Bankrupt Member
or its representative and the Members; however, if those Persons do not agree on
the fair market value on or before the thirtieth (30th) day following the
exercise of the option, either such Person, by notice to the other, may require
the determination of fair market value to be made by an independent appraiser
specified in that notice. If the Person receiving that notice objects on or
before the tenth (10th) day following receipt to the independent appraiser, each
such Person may petition the United States District Judge for the District of
Delaware then senior in service to designate an independent appraiser. The
determination of the independent appraiser, however designated, shall be final
and binding on all parties. The Bankrupt Member and the Company each shall pay
one-half (1/2) of the costs of the appraisal. The purchaser shall pay the fair
market value as so determined in four (4) equal cash installments, the first due
on closing and the remainder (together with accumulated interest on the amount
unpaid at the General Interest Rate) due on each of the first three (3)
anniversaries thereof. The amount may be prepaid at any time without penalty.
The payment to be made to the Bankrupt Member or its representative pursuant to
this Section 12.01 is in complete satisfaction of all the rights and interests
of the Bankrupt Member and its representative (and all Persons claiming by,
through or under the Bankrupt Member and its representative) in respect of the
Company, including, without limitation, any Membership Interest, any rights in
specific Company Property and any rights against the Company and (insofar as the
affairs of the Company are concerned) against the Members, and constitutes a
compromise to which all Members have agreed.

                                  ARTICLE 13.

           DISSOLUTION, LIQUIDATION, TERMINATION AND RECONSTITUTION

      13.01 Dissolution. The Company shall dissolve and shall commence winding
up and liquidating upon the first to occur of the following (each a "Dissolution
Event"):


                                       44
<PAGE>   53
      (a) the dissolution of the Partnership;

      (b) the unanimous written consent of all the Membership Interests of all
Members that are not Withdrawing Members to dissolve, wind up and liquidate the
Company;

      (c) the sale of all or substantially all of the Property;

      (d) a judicial determination that an event has occurred that makes it
unlawful, impossible or impracticable to carry on the business and the entry of
a decree of judicial dissolution of the Company under Section 18-802 of the Act;
or

      (e) any other event of dissolution of the Company under Section 18-801 of
the Act.

      13.02 Winding Up, Liquidation and Termination. On dissolution of the
Company, the Members shall act as liquidator or may appoint one or more Members
as liquidator. The liquidator shall proceed diligently to wind up the affairs of
the Company and make final distributions as provided herein and in the Act. The
costs of liquidation shall be borne as a Company expense. Until final
distribution, the liquidator shall continue to operate the Company Properties
with all of the power and authority of the Members. The steps to be accomplished
by the liquidator are as follows:

      (a) as promptly as possible after dissolution and again after final
liquidation, the liquidator shall cause a proper accounting to be made by a
recognized firm of certified public accountants of the Company's assets,
liabilities and operations through the last day of the calendar month in which
the dissolution occurs or the final liquidation is completed, where applicable;

      (b) the liquidator shall cause notice of dissolution to be mailed to each
known creditor and claimant against the Company;

      (c) the liquidator shall pay, satisfy or discharge all of the debts,
liabilities and obligations of the Company (including, without limitations, all
expenses incurred in liquidation and any advances described in Section 4.05)
from Company funds or otherwise make adequate provision for payment and
discharge thereof (including, without limitation, the establishment of a cash
escrow fund for contingent liabilities in such amount and for such term as the
liquidator may reasonably determine); and

      (d) all remaining assets of the Company shall be distributed to the
Members as follows:

            (i) the liquidator may sell any or all Property, including to
      Members, and any resulting gain or loss from each sale shall be computed
      and allocated to the capital accounts of the Members;

            (ii) with respect to all Property that has not been sold, the fair
      market value of that Property shall be determined and the Capital Accounts
      of the Members shall be adjusted to


                                       45
<PAGE>   54
      reflect the manner in which the unrealized income, gain, loss and
      deduction inherent in Property that has not been reflected in the Capital
      Accounts previously would be allocated among the Members if there were a
      taxable disposition of that Property for the fair market value of that
      Property on the date of distribution; and

            (iii) Property, including cash, shall be distributed to the Members,
      in proportion to their positive Capital Accounts as of the date of such
      distribution, after giving effect to all contributions, distributions and
      allocations for all periods.

      All distributions in kind to the Members shall be made subject to the
liability of each distributee for costs, expenses and liabilities theretofore
incurred or for which the Company has committed prior to the date of termination
and those costs, expenses and liabilities shall be allocated to the distributee
pursuant to this Section 13.02. The distribution of cash and/or Property to a
Member in accordance with the provisions of this Section 13.02 constitutes a
complete return to the Member of its Capital Contributions and a complete
distribution to the Member of its Membership Interest and all the Company's
Property. To the extent that a Member returns funds to the Company, it has no
claim against any other Member for those funds.

      13.03 Deficit Capital Accounts. Notwithstanding anything to the contrary
contained in these Regulations, and notwithstanding any custom or rule of law to
the contrary, to the extent that the deficit, if any, in the Capital Account of
any Member results from or is attributable to deductions and losses of the
Company (including non-cash items such as depreciation) or distributions of
money pursuant to these Regulations to all Members in proportion to their
respective Membership Interests, upon dissolution of the Company such deficit
shall not be an asset of the Company and such Members shall not be obligated to
contribute such amount to the Company to bring the balance of such Member's
Capital Account to zero.

      13.04 Certificate of Dissolution. On completion of the distribution of
Company assets as provided herein, the Company shall be terminated, and the
Members (or such other Person or Persons as the Act may require or permit) shall
file or cause to be filed a Certificate of Dissolution with the Secretary of
State of the State of Delaware, and cancel any other filings as may be necessary
to dissolve the Company.

      13.05 Reconstitution. If it is determined, by a court of competent
jurisdiction, that the Company has dissolved prior to the occurrence of a
Dissolution Event, then, within an additional ninety (90) days after such
determination (the "Reconstitution Period"), all of the Members may elect to
reconstitute the Company and continue its business on the same terms and
conditions set forth in these Regulations by forming a new limited liability
company on terms identical to those set forth in these Regulations. Unless such
an election is made within the Reconstitution Period, the Company shall
liquidate and wind up its affairs in accordance with Section 13.02 hereof. If
such an election is made within the Reconstitution Period, then:


                                       46
<PAGE>   55
      (a) the reconstituted limited liability company shall continue until the
occurrence of a Dissolution Event as provided in Section 13.01 hereof; and

      (b) unless otherwise agreed to by a Required Interest, the Certificate and
these Regulations shall automatically constitute the Certificate and Regulations
of such new Company. All of the assets and liabilities of the dissolved Company
shall be deemed to have been automatically assigned, assumed, conveyed and
transferred to the new Company. No bond, collateral, assumption or release of
any Member's or the Company's liabilities shall be required; provided, that the
right of the Members to select successor managers and to reconstitute and
continue the business shall not exist and may not be exercised unless the
Company has received an opinion of counsel that the exercise of the right would
not result in the loss of limited liability of any Member and neither the
Company nor the reconstituted limited liability company would cease to be
treated as a partnership for federal income tax purposes upon the exercise of
such right to continue.

                                  ARTICLE 14.

                              DISPUTE RESOLUTION

      14.01 Disputes. This Article 14 shall apply to any dispute arising under
or related to these Regulations (whether arising in contract, tort or otherwise,
and whether arising at law or in equity), including (a) any dispute regarding
the construction, interpretation, performance, validity or enforceability of any
provision of these Regulations or whether any Person is in compliance with, or
in breach of, any provisions of these Regulations, and (b) the applicability of
this Article 14 to a particular dispute (collectively, a "Dispute").

      14.02 Negotiations to Resolve Disputes. The Members shall endeavor to
resolve any Disputes in a prompt and equitable manner. In the event a Dispute
arises which the Members are unable to resolve, the Members shall, prior to the
initiation of any claim or cause of action, each appoint an officer or
representative that has settlement authority to meet (in person or by telephone
conference) in an effort to resolve the Dispute equitably, in good faith and as
quickly as is reasonably possible. No settlement shall be binding until reduced
to writing and signed by the Members. The responsibility of these
representatives shall be to resolve the matter or propose a method of resolving
the matter, if possible. If the Dispute is not settled or resolved by the
earlier of (a) sixty (60) days following the first meeting of the
representatives and (b) at such time as the representatives unanimously agree
that a resolution of the Dispute is not possible, then the Members may proceed
as set forth in Section 14.03.

      14.03 Arbitration. Subject to Section 14.02 hereof, any Dispute shall be
settled by binding arbitration administered by the American Arbitration
Association (the "AAA") under its Commercial Arbitration Rules, and judgment on
the award rendered by the arbitrator(s) may be entered in any court of competent
jurisdiction. All Members further agree to waive the fifty thousand dollar
($50,000) maximum claim amount applicable to the Expedited Procedures contained
in the Commercial Arbitration Rules, and agree to submit to such Expedited
Procedures, along with the


                                       47
<PAGE>   56
additional discovery-related rules outlined below, in all Disputes subject to
arbitration hereunder. In no event may the initiation of arbitration by written
submission to the AAA be given more than one (1) year after the date of the
claim, Dispute or controversy or other matter in question was first asserted in
writing to the other Member or Members in accordance with Section 14.02 above.
The Members shall adhere to the following schedule for exchange of information
upon commencement of arbitration under the Commercial Arbitration Rules:

      (a) Within seven (7) days of the service by the responding Member of an
answering statement upon the complaining Member, the complaining Member shall
serve upon the responding Member a copy of each document in possession of the
complaining Member and a list of any witnesses, excluding those documents and
witnesses to be used for cross-examination or rebuttal, that the complaining
Member intends to rely upon at the arbitration;

      (b) Within thirty (30) days of the service by the responding Member of an
answering statement upon the complaining Member, the responding Member shall
provide a list of any witnesses it intends to call at arbitration and a list of
all documents it intends to rely on at arbitration, excluding those documents
and witnesses to be used for cross-examination or rebuttal;

      (c) Any Member may serve written requests for information and documents
(the "Information Request") upon another Member within thirty (30) days of the
filing of the answering statement, subject to the following limitations:

            (i) Each Member may serve not more than one (1) set of
      interrogatories limited to ten (10) items;

            (ii) Each Member may depose the other Member's expert witnesses, if
      any, who will be called to testify at the hearing, plus four (4) fact
      witnesses without regard to whether they will be called to testify. Each
      Member will be entitled to a total of not more than twenty-four (24) hours
      of depositions of the other Member's witnesses, including, but not limited
      to, the witnesses referred to herein. All depositions to be taken by a
      Member are to be scheduled and completed within one hundred twenty (120)
      days of the filing of the answering statement.

      (d) Information Requests, except as otherwise provided herein, shall be
satisfied or objected to within twenty (20) days from the date of service of the
Information Request;

      (e) Any response to objections to an Information Request shall be served
within ten (10) days of receipt of the objection;

      (f) Upon the written request of a Member whose Information Request is
unsatisfied, the matter will be considered by the arbitrator(s) at a preliminary
hearing held in accordance with the Commercial Arbitration Rules.


                                       48
<PAGE>   57
                                  ARTICLE 15.

                              GENERAL PROVISIONS

      15.01 Regulations Subordinate to Member Agreement. Any term or provision
in any Member Agreement of even date herewith or later entered into between the
Members that conflicts with any term or provision in these Regulations shall
take precedence over any term or provision in these Regulations, and the
conflicting term or provision in these Regulations shall be modified or
interpreted in accordance with such Member Agreement.

      15.02 Compliance with Partnership Agreement. Notwithstanding anything
contained herein to the contrary, neither the Company nor any Member (nor any
Affiliate of the Company or any Member) shall take any action which is in
violation of or may cause a violation of the terms or conditions of the
Partnership Agreement.

      15.03 Payments and Offset. Whenever the Company is to pay any sum to any
Member, any amounts that Member owes the Company may be deducted from that sum
before payment. If any payment due hereunder (excluding a Capital Contribution)
is not made when due, it shall accrue interest at the Base Interest Rate.

      15.04 Notices. Except as expressly set forth to the contrary in these
Regulations, all notices, requests, or consents provided for or permitted to be
given under these Regulations must be in writing and must be given either by
depositing that writing in the United States mail, addressed to the recipient,
postage paid, and registered or certified with return receipt requested or by
delivering that writing to the recipient in person, by courier or by facsimile
transmission, a notice, request, or consent given under these Regulations is
effective on receipt by the Person who is to receive it. All notices, requests
and consents to be sent to a Member must be sent to or made at the addresses
given for that Member listed below or such other address as that Member may
specify by notice to the other Members. Whenever any notice is required to be
given by law, the Certificate or these Regulations, a written waiver thereof,
signed by the Person entitled to notice, whether before or after the time stated
therein, shall be deemed equivalent to the giving of such notice.

If to the Company:               Millennium Pipeline Management
                                 Company, L.L.C.
                                 12801 Fair Lakes Parkway
                                 P.O. Box 10146
                                 Fairfax, Virginia 22030
                                 Attn: Mr. David C. Pentzien, Chairman
                                 Telephone: (703) 227-3223
                                 Telecopy: (304) 227-3326


                                      49
<PAGE>   58
If to Columbia:                  Columbia Gas Transmission Corporation
                                 12801 Fair Lakes Parkway
                                 P.O. Box 10146
                                 Fairfax, Virginia 22030
                                 Attn: Mr. David C. Pentzien
                                 Telephone: (703) 227-3223
                                 Telecopy: (304) 227-3326

If to MCN:                       MCNIC LLC Millennium Company
                                 City Place I
                                 185 Asylum Street, 32nd Floor
                                 Hartford, CT 06103
                                 Attn: Mr. Mike Feodorov
                                 Telephone: (860) 275-6460
                                 Telecopy: (860) 275-6245

If to TransCanada:               TransCanada PipeLine USA Ltd.
                                 TransCanada PipeLines Tower
                                 511 5th Avenue, SW
                                 Calgary, Alberta
                                 Canada T2P 3Y6
                                 Attn: Mr. Brian Fowler
                                 Telephone: (403) 267-1908
                                 Telecopy: (403) 267-8573

If to Westcoast:                 Westcoast Power Marketing Inc.
                                 50 Keil Drive North
                                 Chatham, Ontario
                                 Canada N7M 5M1
                                 Attn: Mr. John Wolnik
                                 Telephone: (519) 436-4567
                                 Telecopy: (519) 436-4521

      15.05 Ratification. The Members hereby ratify, approve, adopt and confirm
as an act of the Company acting as General Partner of the Partnership all lawful
acts taken pursuant to the MOU by the management committee or its members or
chairman established under the MOU whether in the name of the Company, the
Partnership or otherwise, including the filing of the documents pursuant to
which application was made on behalf of the Partnership for the regulatory
authorizations from the FERC for authority to construct, own, operate and
maintain the Millennium Pipeline System and for the authority to provide natural
gas transportation using the Millennium Pipeline System.


                                       50
<PAGE>   59
      15.06 Entire Agreement; Acknowledgment.

      (a) These Regulations constitute the entire agreement of the Members and
their Affiliates relating to the Company and, subject to Section 15.01 hereof,
supersede all prior contracts or agreements with respect to the Company, whether
oral or written, including the MOU.

      (b) The Members expressly acknowledge that, without limiting the effect of
subsection 15.06(a), the obligations of each Member shall be limited to those
expressly contained in these Regulations, the Partnership Agreement and any
Project Agreements to which such Member is a party, and there are no additional
express or implied obligations or understandings of the said Member or any of
its Affiliates in respect of the Millennium Pipeline System, fiduciary or
otherwise.

      15.07 Effect of Waiver or Consent. A waiver or consent, express or
implied, to or of any breach or default by any Person in the performance by that
Person of its obligations with respect to the Company is not a consent or waiver
to or of any other breach or default in the performance by that Person of the
same or any other obligations of that Person with respect to the Company.
Failure of any Person to complain of any act of any other Person or to declare
such other Person in default with respect to the Company, irrespective of how
long that failure continues, does not constitute a waiver by the Company of its
rights with respect to that default until the applicable statute-of-limitations
period has run.

      15.08 Amendment or Modification. These Regulations may be amended or
modified from time to time only by a written instrument adopted by a majority of
the Members and executed and agreed to by a Required Interest; provided,
however, that (a) an amendment or modification reducing a Member's Membership
Interest (other than to reflect changes otherwise provided by these Regulations)
is effective only with that Member's consent, (b) an amendment or modification
reducing the required Membership Interest or other measure for any consent or
vote in these Regulations is effective only with the consent or vote of the
Members having the Membership Interest or other measure theretofore required and
(c) amendments of the type described in Section 3.05 hereof may be adopted as
therein provided.

      15.09 Binding Effect. Subject to the restrictions on Dispositions set
forth in these Regulations, these Regulations are binding on and inure to the
benefit of the Members and their respective heirs, legal representatives,
successors and assigns. The executors, administrators or personal
representatives of a Member shall execute and deliver any and all instruments
and documents and shall do any and all acts and things necessary and appropriate
to carry out the terms and provisions of these Resolutions.


                                       51
<PAGE>   60
      15.10 Governing Law. THESE REGULATIONS ARE GOVERNED AND SHALL BE CONSTRUED
IN ACCORDANCE WITH THE LAW OF THE STATE OF DELAWARE, EXCLUDING ANY
CONFLICT-OF-LAWS RULE OR PRINCIPLE THAT MIGHT REFER THE GOVERNANCE OR THE
CONSTRUCTION OF THESE REGULATIONS TO THE LAW OF ANOTHER JURISDICTION. In the
event of a direct conflict between the provisions of these Regulations and (a)
any provision of the Certificate or (b) any mandatory provision of the Act or
(to the extent such statutes are incorporated into the Act) the DGCL, the
applicable provision of the Certificate, the Act or the DGCL shall control.

      15.11 Severability. If any provision of these Regulations or the
application thereof to any Person or circumstance is held invalid or
unenforceable to any extent, the remainder of these Regulations and the
application of the provision to other Persons or circumstances is not affected
thereby and that provision shall be enforced to the greatest extent permitted by
law.

      15.12 Further Assurances. In connection with these Regulations and the
transactions contemplated hereby, each Member shall execute and deliver any
additional documents and instruments and perform any additional acts that may be
necessary or appropriate to effectuate and perform the provisions of these
Regulations and those transactions.

      15.13 Waiver of Certain Rights. Each Member irrevocably waives any right
it may have to maintain any action for dissolution of the Company or for
partition of the Property of the Company.

      15.14 Indemnification. To the fullest extent permitted by law, each Member
shall indemnify the Company and hold it harmless from and against all losses,
costs, liabilities, damages, and expenses (including, without limitation, costs
of suit and attorneys' fees) they may incur on account of any breach by that
Member of these Regulations.

      15.15 Notice to Members of Provisions of these Regulations. By executing
these Regulations, each Member acknowledges that it has actual notice of (a) all
of the provisions of these Regulations, including, without limitation, the
restrictions on the Disposition of Membership Interests, set forth in Article 3,
and (b) all of the provisions of the Certificate. Each Member hereby agrees that
these Regulations constitute adequate notice of all such provisions, including,
without limitation, any notice requirement under the Act and Article 8 of the
UCC, and each Member hereby waives any requirement that any further notice
thereunder be given.

      15.16 Counterparts. These Regulations may be executed in any number of
counterparts with the same effect as if all signing parties had signed the same
document. All counterparts shall be construed together and constitute the same
instrument.

                           [SIGNATURE PAGES FOLLOW]


                                       52
<PAGE>   61
      IN WITNESS WHEREOF, the Members have executed these Regulations as of the
date first set forth above.

                                          MEMBERS:

                                          Columbia Gas Transmission Corporation,
                                          a Delaware corporation

                                          By:__________________________________
                                          Printed Name:________________________
                                          Title:_______________________________


                  [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]

                THIS IS A SIGNATURE PAGE TO THE REGULATIONS OF
                  MILLENNIUM PIPELINE MANAGEMENT CO., L.L.C.
<PAGE>   62
      IN WITNESS WHEREOF, the Members have executed these Regulations as of the
date first set forth above.

                                          MCNIC LLC Millennium Company,
                                          a Michigan corporation

                                          By:__________________________________
                                          Printed Name:________________________
                                          Title:_______________________________



                  [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]

                THIS IS A SIGNATURE PAGE TO THE REGULATIONS OF
                  MILLENNIUM PIPELINE MANAGEMENT CO., L.L.C.
<PAGE>   63
      IN WITNESS WHEREOF, the Members have executed these Regulations as of the
date first set forth above.

                                          TransCanada PipeLine USA Ltd..
                                          a Nevada corporation

                                          By:__________________________________
                                          Printed Name:________________________
                                          Title:_______________________________

                                          By:__________________________________
                                          Printed Name:________________________
                                          Title:_______________________________



                  [SIGNATURES CONTINUE ON THE FOLLOWING PAGE]

                THIS IS A SIGNATURE PAGE TO THE REGULATIONS OF
                  MILLENNIUM PIPELINE MANAGEMENT CO., L.L.C.
<PAGE>   64
      IN WITNESS WHEREOF, the Members have executed these Regulations as of the
date first set forth above.

                                          Westcoast Power Marketing Inc.,
                                          a Delaware corporation

                                          By:__________________________________
                                          Printed Name:________________________
                                          Title:_______________________________

                                          By:__________________________________
                                          Printed Name:________________________
                                          Title:_______________________________



                THIS IS A SIGNATURE PAGE TO THE REGULATIONS OF
                  MILLENNIUM PIPELINE MANAGEMENT CO., L.L.C.
<PAGE>   65
                                    EXHIBIT A

      INITIAL MEMBERS, MEMBERSHIP INTEREST AND INITIAL CAPITAL CONTRIBUTION

<TABLE>
<CAPTION>
                                  MEMBERSHIP
         MEMBER                    INTEREST             INITIAL CAPITAL CONTRIBUTION
         ------                    --------             ----------------------------
<S>                               <C>                   <C>
Columbia                             47.5                        US$68,171
MCN                                  10.5%                       US$15,069
TransCanada                           21%                        US$30,139
Westcoast                             21%                        US$30,139
</TABLE>


                               [End of Exhibit A]
<PAGE>   66
                                    EXHIBIT B

                                  MEMBER OWNERS

<TABLE>
<CAPTION>
                                                        OWNERSHIP
  MEMBER              MEMBER OWNER(S)                   PERCENTAGE
  ------              ---------------                   ----------
<S>           <C>                                        <C>
Columbia      Columbia Energy Group,                      100%
              a Delaware corporation

Westcoast     Westcoast Energy, Inc.,                     100%
              a Delaware corporation

MCN           MCNIC Pipeline and Processing Company,      100%
              a Michigan corporation

TransCanada   TransCanada PipeLines Limited,              100%
              a Canada corporation
</TABLE>


                               [End of Exhibit B]
<PAGE>   67
                                   EXHIBIT C

                         INITIAL MANAGEMENT COMMITTEE

The initial Management Committee Members shall be as follows:

<TABLE>
<CAPTION>
        MEMBER               MANAGEMENT COMMITTEE
        ------                  REPRESENTATIVE
                                --------------
<S>                    <C>
Columbia               David C. Pentzien (Initial Chairman)
Westcoast              John Wolnik
MCN                    Mike Feodorov
TransCanada            Brian Fowler
</TABLE>


                               [End of Exhibit C]
<PAGE>   68
                                    EXHIBIT D

                                INITIAL OFFICERS

The initial officer(s) of the Company shall be as follows:

      David C. Pentzien -     Chairman



                              [End of Exhibit D]



<PAGE>   1
                                                                    Exhibit 10CK



                              AMENDED AND RESTATED
                            364-DAY CREDIT AGREEMENT

                                        Dated as of March 10, 1999

                  THIS AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT (this
"Amendment and Restatement") among COLUMBIA ENERGY GROUP, a Delaware corporation
(the "Borrower"), the banks, financial institutions and other institutional
lenders parties to the Credit Agreement referred to below (collectively, the
"Lenders"), and SALOMON SMITH BARNEY INC., as arranger and book manager
("Arranger and Book Manager"), and CITIBANK, N.A. ("Citibank"), as
administrative and syndication agent (the "Agent") for the Lenders, evidences
the agreement of the parties as follows:

                  PRELIMINARY STATEMENTS:

                  (1) The Borrower, the Lenders and the Agent have entered into
a 364-Day Credit Agreement originally dated as of March 11, 1998 (the "Credit
Agreement"). Capitalized terms not otherwise defined in this Amendment and
Restatement have the same meanings as specified in the Credit Agreement.

                  (2) The Borrower and the Lenders have agreed to amend the
Credit Agreement as hereinafter set forth and to restate the Credit Agreement in
its entirety to read as set forth in the Credit Agreement with the amendments
specified below.

                  SECTION 1. Amendments to Credit Agreement. The Credit
Agreement shall be effective as of the date hereof and, subject to the
satisfaction of the conditions precedent set forth in Section 3.02, is hereby
amended as follows:

                  (a) The following definitions appearing in Section 1.01 are
         amended in full to read as follows:

                           "Arranger and Book Manager" means Salomon Smith
                  Barney Inc., as arranger of the syndicate of Lenders
                  hereunder.

                           "Critical Third Parties" shall have the meaning
                  specified in Section 4.01(m).
<PAGE>   2
                                        2

                           "Information Memorandum" means the information
                  memorandum dated February 1999 used by the Arranger and Book
                  Manager in connection with the syndication of the Revolving
                  Credit Commitments.

                           "Termination Date" means the earlier of (a) March 8,
                  2000 or, if extended pursuant to Section 2.16(a), the date
                  that is 364 days after the Termination Date then in effect,
                  and (b) the date of termination in whole of the Revolving
                  Credit Commitments pursuant to Section 2.03 or 6.01.

                           "Year 2000 Problem" and "Year 2000 Compliant" shall
                  have the meanings specified in Section 4.01(m).

                           (b) The chart contained in the definition of
         "Applicable Margin" in Section 1.01 is amended to read in full as set
         forth on Exhibit A hereto.

                           (c) Section 2.07 is amended by adding a new Section
         2.07(e) which reads as follows:

                           "(e) Utilization Fee. With respect to every day on
                  which the sum of all outstanding Advances is greater than 25%
                  of the aggregate amount of the Revolving Credit Commitments,
                  the Borrower agrees to pay to the Agent for the account of
                  each Lender a utilization fee based on the daily aggregate
                  amount of such Lender's Revolving Credit Commitment,
                  calculated on a daily basis and payable quarterly in arrears
                  at a rate per annum equal at all times to either (i) the lower
                  percentage set forth in Column 6 of Exhibit A hereto during
                  such periods as the sum of all outstanding Advances is greater
                  than 25% but not more than 75% of the aggregate amount of the
                  Revolving Credit Commitments, or (ii) the higher percentage
                  set forth in Column 6 of Exhibit A hereto during such periods
                  as the sum of all outstanding Advances is greater than 75% of
                  the aggregate amount of the Revolving Credit Commitments."

                  (d) Section 2.12 is amended to delete the word "facility" in
         each place in which said word appears therein.

                  (e) Section 3.01(a) is amended by deleting the reference to
         "December 31, 1996" and substituting "December 31, 1997" therefor.

                  (f) Section 4.01(e) is amended by deleting the reference to
         "December 31, 1996" in each place in which it appears and substituting
         "December 31, 1997" therefor, and deleting the reference to "September
         30, 1997" in each place in which it appears and substituting "September
         30, 1998" therefor.
<PAGE>   3
                                        3

                  (g) Section 4.01 is amended by adding Section 4.01(m) which
         reads as follows:

                           "(m) The Borrower has (i) initiated a review and
                  assessment of all areas within its and each of its
                  Subsidiaries' business and operations (including those
                  affected by suppliers, vendors and customers that, in each
                  case, are material to the business and operations of the
                  Borrower and its Subsidiaries taken as a whole ("Critical
                  Third Parties")) that could be adversely affected by the
                  inability of computer applications used by the Borrower or any
                  of its Subsidiaries (or Critical Third Parties) to recognize
                  and perform properly date-sensitive functions involving dates
                  on or after January 1, 2000 (the "Year 2000 Problem"), (ii)
                  developed a plan and timetable for addressing the Year 2000
                  Problem on a timely basis and (iii) to date, implemented that
                  plan in accordance with such timetable. Based on the
                  foregoing, the Borrower believes that all computer
                  applications used by the Borrower or any of its Subsidiaries
                  that are material to the business and operations of the
                  Borrower and its Subsidiaries taken as a whole are reasonably
                  expected on a timely basis to be able to perform properly
                  date-sensitive functions for all dates on or after January 1,
                  2000 ("Year 2000 Compliant"), except to the extent that a
                  failure to do so could not reasonably be expected to have a
                  Material Adverse Effect."

                  (h) Section 5.01(i) is amended by deleting the word "and"
         following Section 5.01 (i)(xi), adding a new Section 5.01(i)(xii) which
         reads as set forth below, and re-designating Section 5.01(i)(xii) as
         Section 5.01(i)(xiii):

                           "(xii) promptly after the Borrower's discovery or
                  determination thereof, notice (in reasonable detail) that any
                  computer application (including those of Critical Third
                  Parties) that is material to the business and operations of
                  the Borrower and its Subsidiaries taken as a whole will not be
                  Year 2000 Compliant, except to the extent that such failure
                  could not reasonably be expected to have a Material Adverse
                  Effect."

                  (i) The Commitments are amended to read in full as set forth
         on Schedule I hereto.

                  SECTION 2. Conditions of Effectiveness. This Amendment and
Restatement shall become effective as of the date first above written when, and
only when, the Agent shall have received counterparts of this Amendment and
Restatement executed by the Borrower and all of the Lenders that have a
Commitment greater than $0 on Schedule I or, as to any of the Lenders, advice
satisfactory to the Agent that such Lender has executed this Amendment and
Restatement and when the Agent shall have additionally received all of the
following documents, each such document (unless otherwise specified) dated the
date of receipt thereof
<PAGE>   4
                                        4

by the Agent (unless otherwise specified) and (except for the Revolving Credit
Notes) in sufficient copies for each Lender, in form and substance satisfactory
to the Agent (unless otherwise specified):

                  (a) The new Revolving Credit Notes issued in connection with
         this Amendment and Restatement to the order of each of the Lenders
         which has a Commitment in a different amount from that with respect to
         the Credit Agreement.

                  (b) Certified copies of (i) the resolutions of the Board of
         Directors of the Borrower approving (or authorizing the transactions
         encompassed by) this Amendment and Restatement and (ii) all documents
         evidencing other necessary corporate action and governmental approvals,
         if any, with respect to this Amendment and Restatement.

                  (c) A certificate of the Secretary or an Assistant Secretary
         of the Borrower certifying the names and true signatures of the
         officers of the Borrower authorized to sign this Amendment and
         Restatement and the other documents to be delivered hereunder.

                  (d) A favorable opinion of LeBoeuf, Lamb, Greene & MacRae,
         L.L.P., counsel for the Borrower, in substantially the form of Exhibit
         B hereto.

                  (e) A favorable opinion of Shearman & Sterling, counsel for
         the Agent, in form and substance satisfactory to the Agent.

                  (f) A certificate signed by a duly authorized officer of the
         Borrower stating that:

                           (i) The representations and warranties contained in
                  Section 4.01 of the Credit Agreement and in Section 3 hereof
                  are correct on and as of the date of such certificate as
                  though made on and as of such date; and

                           (ii) No event has occurred and is continuing that
                  constitutes a Default.

                  SECTION 3. Representations and Warranties of the Borrower. The
Borrower represents and warrants as follows:

                  (a) The execution, delivery and performance by the Borrower of
         this Amendment and Restatement are within the Borrower's corporate
         powers, have been duly authorized by all necessary corporate action and
         do not contravene (i) the Borrower's charter or by-laws or (ii) any law
         or any contractual restriction binding on
<PAGE>   5
                                        5

         or affecting the Borrower, except where such contravention would not be
         reasonably likely to have a Material Adverse Effect.

                  (b) No authorization or approval or other action by, and no
         notice to or filing with, any governmental authority or regulatory body
         or any other third party is required for the due execution, delivery or
         performance by the Borrower of this Amendment and Restatement, except
         where the Borrower's failure to receive, take or make such
         authorization, approval, action, notice or filing would not have a
         Material Adverse Effect.

                  (c) This Amendment and Restatement has been duly executed and
         delivered by the Borrower. This Amendment and Restatement is a legal,
         valid and binding obligation of the Borrower, enforceable against the
         Borrower in accordance with its terms, subject to applicable
         bankruptcy, reorganization, insolvency, moratorium or similar laws
         affecting creditors' rights generally and general principles of equity.

                  SECTION 4. Reference to and Effect on the Credit Agreement.
(a) On and after the effectiveness of this Amendment and Restatement, each
reference in the Credit Agreement to "this Agreement", "hereunder", "hereof" or
words of like import referring to the Credit Agreement, shall mean and be a
reference to the Credit Agreement, as amended and restated by this Amendment and
Restatement; provided, however, that the word "hereafter" appearing in the
definition of "Material Subsidiaries" in Section 1.01 shall refer to the period
after March 11, 1998. Each Lender on Schedule I with a Commitment of "$0" shall
cease to be a party to the Credit Agreement.

                  (b) The Credit Agreement, as specifically amended and restated
by this Amendment and Restatement, is and shall continue to be in full force and
effect and is hereby in all respects ratified and confirmed.

                  (c) The execution, delivery and effectiveness of this
Amendment and Restatement shall not, except as expressly provided herein,
operate as a waiver of any right, power or remedy of any Lender or the Agent
under the Credit Agreement, nor constitute a waiver of any provision of the
Credit Agreement.

                  SECTION 5. Costs, Expenses, Etc. The Borrower agrees to pay on
demand all costs and expenses of the Agent in connection with the preparation,
execution, delivery and administration, modification and amendment of this
Amendment and Restatement and the other instruments and documents to be
delivered hereunder (including, without limitation, the reasonable fees and
expenses of counsel for the Agent) in accordance with the terms of Section 8.04
of the Credit Agreement. The Agent agrees to request as promptly as practicable
from (a) Lenders whose Revolving Credit Notes are being replaced pursuant to
this
<PAGE>   6
                                        6

Amendment and Restatement as of the date hereof, and (b) Lenders who shall have
ceased to be parties to the Credit Agreement as of the date hereof, the return
of their old Revolving Credit Notes. The Agent agrees to release any new
Revolving Credit Note payable to a Lender only upon the return of the old
Revolving Credit Note payable to such Lender.

                  SECTION 6. Execution in Counterparts. This Amendment and
Restatement may be executed in any number of counterparts and by different
parties hereto on separate counterparts, each of which when so executed shall be
deemed to be an original and all of which taken together shall constitute but
one and the same agreement. Delivery of an executed counterpart of a signature
page to this Amendment and Restatement by telecopier shall be effective as
delivery of a manually executed counterpart of this Amendment and Restatement.

                  SECTION 7. Governing Law. This Amendment and Restatement shall
be governed by, and construed in accordance with, the laws of the State of New
York.

                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment and Restatement to be executed by their respective officers thereunto
duly authorized, as of the date first above written.


                                  COLUMBIA ENERGY GROUP


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


                                  SALOMON SMITH BARNEY INC.,
                                    as Arranger and Book Manager


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


                                  CITIBANK, N.A.,
                                    as Administrative and Syndication Agent


                                  By
                                     ------------------------------------
                                     Title:
<PAGE>   7
                                        7

                              Lenders


                                  CITIBANK, N.A.


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


                                  THE CHASE MANHATTAN BANK


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


                                  PNC BANK, NATIONAL
                                  ASSOCIATION


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


                                  CANADIAN IMPERIAL BANK OF
                                  COMMERCE


                                  By
                                     ------------------------------------
                                     Name:
                                     Title:
<PAGE>   8
                                        8

                                  BANK OF MONTREAL


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


                                  FIRST UNION NATIONAL BANK


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


                                  THE BANK OF NOVA SCOTIA


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


                                  THE FIRST NATIONAL BANK OF
                                  CHICAGO


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


                                  BANKERS TRUST COMPANY


                                  By
                                     ------------------------------------
                                     Name:
                                     Title:
<PAGE>   9
                                        9


                                  CRESTAR BANK


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


                                  THE FIRST NATIONAL BANK OF
                                  MARYLAND, A DIVISION OF FMB
                                  BANK


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


                                  NATIONAL CITY BANK


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


                                  COMMERZBANK AG,
                                  NEW YORK BRANCH


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

                                  By
                                     ------------------------------------
                                     Name:
                                     Title:
<PAGE>   10
                                       10

                                  BANK OF TOKYO-MITSUBISHI
                                  TRUST COMPANY


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


                                  UNION BANK OF CALIFORNIA


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


                                  ARAB BANK, PLC


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


                                  BANCA MONTE DEI PASCHI DI
                                  SIENA S.p.A.


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


                                  By
                                     ------------------------------------
                                     Name:
                                     Title:
<PAGE>   11
                                       11

                                  BANK OF AMERICA N.T. & S.A.


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


                                  SOCIETE GENERALE


                                  By
                                     ------------------------------------
                                     Name:
                                     Title:
<PAGE>   12
                                       12


                                   SCHEDULE I

<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------------------------
    NAME OF INITIAL LENDER             DOMESTIC LENDING OFFICE             EURODOLLAR LENDING OFFICE        AMOUNT OF COMMITMENT
- -----------------------------------------------------------------------------------------------------------------------------------
<S>                                 <C>                                  <C>                                <C>
Citibank, N.A.                         2 Penn's Way, Suite 200              2 Penn's Way, Suite 200             $50,000,000
                                        New Castle, DE, 19720                New Castle, DE, 19720
                                          Patrice Williams                      Patrice Williams
                                          Fax: 302-894-6120                    Fax: 302-894-6120
- -----------------------------------------------------------------------------------------------------------------------------------
The Chase Manhattan Bank              1 Chase Manhattan Plaza-            1 Chase Manhattan Plaza- 8th          $50,000,000
                                              8th Floor                              Floor
                                         New York, NY 10081                    New York, NY 10081
                                            Lynette Lang                          Lynette Lang
                                          Tel: 212-552-7692                    Tel: 212-552-7692
                                          Fax: 212-552-5777                    Fax: 212-552-5777
- -----------------------------------------------------------------------------------------------------------------------------------
PNC Bank, National Association         249 Fifth Ave., 6th Fl.              249 Fifth Ave., 6th Fl.             $40,000,000
                                        Pittsburgh, PA 15222                  Pittsburgh, PA 15222
                                             Tina Lanuka                          Tina Lanuka
                                          Tel: 412-768-5876                    Tel: 412-768-5876
                                          Fax: 412-768-4586                    Fax: 412-768-4586
- -----------------------------------------------------------------------------------------------------------------------------------
Canadian Imperial Bank of            Two Paces West, Suite 1200            Two Paces West, Suite 1200           $38,000,000
Commerce                              2727 Paces Ferry Road, NW            2727 Paces Ferry Road, NW
                                          Atlanta, GA 30339                    Atlanta, GA 30339
                                          Tel: 770-319-4821                    Tel: 770-319-4821
                                          Fax: 770-319-4950                    Fax: 770-319-4950
- -----------------------------------------------------------------------------------------------------------------------------------
Bank of Montreal                   115 South LaSalle St., 11th Fl.      115 South LaSalle St., 11th Fl.         $33,333,333
                                          Chicago, IL 60603                    Chicago, IL 60603
                                           Client Services                      Client Services
                                          Tel: 312-750-3758                    Tel: 312-750-3758
                                          Fax: 312-750-4345                    Fax: 312-750-4345
- -----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   13
                                       13

<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------------------------
    NAME OF INITIAL LENDER             DOMESTIC LENDING OFFICE             EURODOLLAR LENDING OFFICE        AMOUNT OF COMMITMENT
- -----------------------------------------------------------------------------------------------------------------------------------
<S>                                    <C>                               <C>                                <C>
First Union National Bank            One First Union Center 301            One First Union Center 301           $33,333,333
                                        South College Street                  South College Street
                                         Charlotte, NC 28209                  Charlotte, NC 28209
                                            Dave Johnson                          Dave Johnson
                                          Tel: 704-383-7686                    Tel: 704-383-7686
                                          Fax: 704-383-6670                    Fax: 704-383-6670
- -----------------------------------------------------------------------------------------------------------------------------------
The Bank of Nova Scotia          600 Peachtree Street NE, Suite 2700        600 Peachtree Street NE,            $30,000,000
                                          Atlanta, GA 30308                        Suite 2700
                                            Cleve Buchey                       Atlanta, GA 30308
                                          Tel: 404-877-1500                       Cleve Buchey
                                           Telex: 00542319                      Tel: 404-877-1500
                                          Fax: 404-888-8998                     Telex: 00542319
                                                                               Fax: 404-888-8998
- -----------------------------------------------------------------------------------------------------------------------------------
The First National Bank of      One First National Plaza, Suite 0363       One First National Plaza,            $25,000,000
Chicago                                   Chicago, IL 60670                        Suite 0363
                                            Kenneth Bauer                      Chicago, IL 60670
                                          Tel: 312-732-6282                      Kenneth Bauer
                                          Fax: 312-732-3055                    Tel: 312-732-6282
                                                                               Fax: 312-732-3055
- -----------------------------------------------------------------------------------------------------------------------------------
Bankers Trust Company              130 Liberty Street, 14th Floor        130 Liberty Street, 14th Floor         $25,000,000
                                         New York, NY 10006                    New York, NY 10006
                                             Jim Cullen                            Jim Cullen
                                          Tel: 212-250-7343                    Tel: 212-250-7343
                                          Fax: 212-250-7351                    Fax: 212-250-7351
- -----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   14
                                       14

<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------------------------
    NAME OF INITIAL LENDER             DOMESTIC LENDING OFFICE             EURODOLLAR LENDING OFFICE        AMOUNT OF COMMITMENT
- -----------------------------------------------------------------------------------------------------------------------------------
<S>                             <C>                                      <C>                                <C>
Crestar Bank                       1445 New York Ave., NW 5th Fl.        1445 New York Ave., NW 5th Fl.         $17,000,000
                                       Washington, D.C. 20005                Washington, D.C. 20005
                                            Nancy Petrash                        Nancy Petrash
                                          Tel: 202-879-6432                    Tel: 202-879-6432
                                          Fax: 202-879-6137                    Fax: 202-879-6137
- -----------------------------------------------------------------------------------------------------------------------------------
The First National Bank of      601 13th St., N.W., Suite 1000 North     601 13th St., N.W., Suite 1000         $16,666,667
Maryland, a division of FMB               Washington, D.C.                           North
Bank                                        Shaun Murphy                        Washington, D.C.
                                          Tel: 202-661-7231                       Shaun Murphy
                                          Fax: 202-661-7238                    Tel: 202-661-7231
                                                                               Fax: 202-661-7238
- -----------------------------------------------------------------------------------------------------------------------------------
National City Bank                      155 East Broad Street                155 East Broad Street              $16,666,667
                                       Columbus, OH 43251-0034              Columbus, OH 43251-0034
                                        Gregory Miller, V.P.                  Gregory Miller, V.P.
                                          Tel: 614-463-8350                    Tel: 614-463-8350
                                          Fax: 614-463-6770                    Fax: 614-463-6770
- -----------------------------------------------------------------------------------------------------------------------------------
Commerzbank AG,                      Two World Financial Center            Two World Financial Center           $15,000,000
New York Branch                          New York, NY 10281                    New York, NY 10281
                                          Dempsey L. Gable                      Dempsey L. Gable
                                          Tel: 212-266-7560                    Tel: 212-266-7560
                                          Fax: 212-266-7530                    Fax: 212-266-7530
- -----------------------------------------------------------------------------------------------------------------------------------
Bank of Tokyo-Mitsubishi Trust       1251 Avenue of the Americas          1251 Avenue of the Americas           $10,000,000
Company                                New York, NY 10020-1104              New York, NY 10020-1104
                                             Rolando Uy                            Rolando Uy
                                          Tel: 212-782-5637                    Tel: 212-782-5637
                                          Fax: 201-413-8225                    Fax: 201-413-8225
- -----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   15
                                       15

<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------------------------
    NAME OF INITIAL LENDER             DOMESTIC LENDING OFFICE             EURODOLLAR LENDING OFFICE        AMOUNT OF COMMITMENT
- -----------------------------------------------------------------------------------------------------------------------------------
<S>                             <C>                                      <C>                                <C>
Union Bank of California               Energy Capital Services              Energy Capital Services             $10,000,000
                                    445 S. Figueroa St., 15th Fl.        445 S. Figueroa St., 15th Fl.
                                        Los Angeles, CA 90071                Los Angeles, CA 90071
                                         David Musicant, VP                    David Musicant, VP
                                          Tel: 213-236-5023                    Tel: 213-236-5023
                                          Fax: 213-236-4096                    Fax: 213-236-4096
- -----------------------------------------------------------------------------------------------------------------------------------
Arab Bank, PLC                            520 Madison Ave.                      520 Madison Ave.                $10,000,000
                                         New York, NY 10022                    New York, NY 10022
                                           John Adams, VP                        John Adams, VP
                                          Tel: 212-715-9765                    Tel: 212-715-9765
                                          Fax: 212-593-4632                    Fax: 212-593-4632
- -----------------------------------------------------------------------------------------------------------------------------------
Banca Monte dei Paschi di           55 East 59th Street- 9th Fl.          55 East 59th Street- 9th Fl.          $10,000,000
Siena S.p.A.                           New York, NY 10022-1112              New York, NY 10022-1112
                                        Nicolas Kanaris V.P.                  Nicolas Kanaris V.P.
                                          Tel: 212-891-3655                    Tel: 212-891-3655
                                          Fax: 212-891-3661                    Fax: 212-891-3661
- -----------------------------------------------------------------------------------------------------------------------------------
Bank of America N.T. & S.A.             700 Louisiana Street                  700 Louisiana Street              $10,000,000
                                              8th Floor                            8th Floor
                                          Houston, TX 77002                    Houston, TX 77002
                                          Tel: 713-247-7373                    Tel: 713-247-7373
                                          Fax: 713-247-6568                    Fax: 713-247-6568
- -----------------------------------------------------------------------------------------------------------------------------------
Societe Generale                         1221 Avenue of the Americas          1221 Avenue of the Americas       $10,000,000
                                             New York, NY 10020                    New York, NY 10020
                                                Gordon Eadon                          Gordon Eadon
                                              Tel: 212-278-6880                    Tel: 212-278-6880
                                              Fax: 212-278-6144                    Fax: 212-278-6144

- -----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   16
                                       16

<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------------------------
    NAME OF INITIAL LENDER             DOMESTIC LENDING OFFICE             EURODOLLAR LENDING OFFICE        AMOUNT OF COMMITMENT
- -----------------------------------------------------------------------------------------------------------------------------------
<S>                             <C>                                      <C>                                <C>
Morgan Guaranty Trust                            60 Wall St.                     Nassau Bahamas Office          $         0
Company of New York                          New York, NY 10260              c/o J.P. Morgan Services, Inc.
                                                  Jim Finch                     Euro-Loan Servicing Unit
                                              Fax: 212-648-5014               500 Stanton Christiana Road
                                                                                    Newark, DE 19713
                                                                                 Telex: 177425 MBDEL UT
                                                                                   Fax: 302-634-1094
- -----------------------------------------------------------------------------------------------------------------------------------
Credit Agricole Indosuez                600 Travis Street, Suite 2340        600 Travis Street, Suite 2340      $         0
                                              Houston, TX 77002                    Houston, TX 77002
                                                Brian Knezeak                        Brian Knezeak
                                              Tel: 713-223-7001                    Tel: 713-223-7001
                                              Fax: 713-223-7029                    Fax: 713-223-7029
- -----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   17
                                                        17

                                                     EXHIBIT A



<TABLE>
<CAPTION>
===================================================================================================================================
    Public Debt Rating     Applicable Margin for     Applicable Margin for     Applicable      Applicable    Applicable Margin for
        S&P/Moody's          Base Rate Advances    Eurodollar Rate Advances      Margin        Margin for       Utilization Fee
                                                                              for CD Rate     Facility Fee         (25%/75%)
                                                                                Advances
===================================================================================================================================
<S>                        <C>                      <C>                       <C>              <C>           <C>
Level 1                              0                         .13%               .255%            .05%            .25%/.375%
  AA-/AA3 or higher
- -----------------------------------------------------------------------------------------------------------------------------------
Level 2                              0                         .20%               .325%            .06%            .25%/.375%
  A+/A/A-/A1/A2/A3
- -----------------------------------------------------------------------------------------------------------------------------------
Level 3                              0                         .215%              .34%             .085%           .30%/.50%
  BBB+/Baa1
- -----------------------------------------------------------------------------------------------------------------------------------
Level 4                              0                         .26%               .385%            .105%           .375%/.625%
  BBB/Baa2
- -----------------------------------------------------------------------------------------------------------------------------------
Level 5                              0                         .31%               .45%             .125%           .50%/.75%
  BBB-/Baa3 or lower
- -----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   18

                                                                  EXECUTION COPY


                                U.S. $450,000,000

                  AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT

                           Dated as of March 10, 1999

                                      among

                             COLUMBIA ENERGY GROUP,

                                  as Borrower,

                                       and

                            THE LENDERS NAMED HEREIN,

                                   as Lenders,

                                       and

                           SALOMON SMITH BARNEY INC.,

                          as Arranger and Book Manager,

                                       and

                                 CITIBANK, N.A.,

                    as Administrative and Syndication Agent,

                                       and

                          THE CHASE MANHATTAN BANK AND
                         PNC BANK, NATIONAL ASSOCIATION,

                            as Documentation Agents,

                                       and

                       CANADIAN IMPERIAL BANK OF COMMERCE,
                   BANK OF MONTREAL, FIRST UNION NATIONAL BANK
                          AND THE BANK OF NOVA SCOTIA,

                           as Senior Managing Agents,

                                       and

                       THE FIRST NATIONAL BANK OF CHICAGO,
                      BANKERS TRUST COMPANY, CRESTAR BANK,
          THE FIRST NATIONAL BANK OF MARYLAND, A DIVISION OF FMB BANK,
              NATIONAL CITY BANK, COMMERZBANK AG, NEW YORK BRANCH,
                   BANK OF TOKYO-MITSUBISHI TRUST COMPANY AND
                            UNION BANK OF CALIFORNIA,

                                  as Co-Agents



<PAGE>   1

                                                                    Exhibit 12


                     COLUMBIA ENERGY GROUP AND SUBSIDIARIES
                     --------------------------------------
                Statements of Ratio of Earnings to Fixed Charges
                ------------------------------------------------
                                 ($ in millions)



<TABLE>
<CAPTION>
                                                                               Twelve Months
                                                                              Ended December 31,
                                                            ---------------------------------------------------------
                                                             1998         1997        1996          1995        1994      
                                                            ------       ------      ------        ------      ------
<S>                                                          <C>         <C>          <C>          <C>          <C>       
Consolidated Income (Loss) from Continuing Operations 
before Income Taxes                                          401.0       392.2        337.5        (643.0)      392.2     
                                                                                                                          
Adjustments:                                                                                                              
 Interest during construction                                 (2.1)       (3.0)        (1.1)        (20.2)         --     
 Distributed (Undistributed) equity income                    (0.4)        3.6          1.5          (7.9)       (0.9)    
 Fixed charges (*)                                           173.1       182.0        184.6       1,061.3        33.7     
                                                             -----       -----        -----       -------       -----     
 Earnings Available                                          571.6       574.8        522.5         390.2       425.0     
                                                             -----       -----        -----       -------       -----     
                                                                                                                          
Fixed Charges:                                                                                                            
 Interest on long-term and short-term debt                   145.4       145.6        150.8         987.2         0.7     
 Other interest                                                9.6        15.4         13.5          53.6        14.1     
 Portion of rentals representing interest                     18.1        21.0         20.3          20.5        18.9     
                                                             -----       -----        -----       -------       -----     
Total Fixed Charges (**), (***)                              173.1       182.0        184.6       1,061.3        33.7     
                                                             -----       -----        -----       -------       -----     

Ratio of Earnings to Fixed Charges                            3.30        3.16         2.83       N/A (a)       12.61    
                                                             =====       =====        =====       =======       =====     
</TABLE>



(a)  To achieve a one-to-one coverage, the Corporation would need an additional
     $671.1 million of earnings in 1995.

     (*)   Amounts for the twelve months ended December 31, 1994 through
           December 31, 1996 have been restated to conform to 1998 presentation.

     (**)  This amount excludes approximately $230 million and $210 million of
           interest expense not recorded for the twelve months ended December
           31, 1994. This amount includes interest expense of $982.9 million
           including the write-off of unamortized discounts on debentures
           recorded in 1995. Reference is made to the Statements of Consolidated
           Income for the twelve months ended December 31, 1995, as reported on
           Form 10-K and Note 2 of Notes to Consolidated Financial Statements of
           the Corporation's Annual Report on Form 10-K for the year ended
           December 31, 1995.

     (***) This amount excludes $8.6 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.

<PAGE>   1
                                                                      EXHIBIT 21


                    SUBSIDIARIES OF THE COLUMBIA ENERGY GROUP
                             as of December 31, 1998


                                                                    State of
        Segment / Subsidiary                                      Incorporation
        --------------------                                      -------------

Transmission and Storage Operations
   Columbia Gas Transmission Corporation                           Delaware
   Columbia Gulf Transmission Company                              Delaware
   Columbia Pipeline Corporation                                   Delaware

Distribution Operations
   Columbia Gas of Kentucky, Inc.                                  Kentucky
   Columbia Gas of Maryland, Inc.                                  Delaware
   Columbia Gas of Ohio, Inc.                                      Ohio
   Columbia Gas of Pennsylvania, Inc.                              Pennsylvania
   Columbia Gas of Virginia, Inc.                                  Virginia

Exploration and Production Operations
   Columbia Energy Resources, Inc.                                 Texas

Marketing Operations 
   Columbia Energy Services Corporation                            Kentucky

Propane, Power Generation and LNG Operations
   Columbia LNG Corporation                                        Delaware
   Columbia Atlantic Trading Corporation                           Delaware
   Columbia Propane Corporation                                    Delaware
   Columbia Electric Corporation                                   Delaware
   Columbia Energy Group Capital Corporation                       Delaware

Corporate
   Columbia Energy Group Service Corporation                       Delaware
   Columbia Insurance Corporation, Ltd                             Bermuda
   Columbia Network Services Corporation                           Delaware

<PAGE>   1
                                                                    EXHIBIT 23-A




                                     CONSENT


            As independent petroleum and natural gas consultants, we hereby
consent to the filing of this Letter Report dated January 22, 1999 in its
entirety as an Exhibit to the 1998 Annual Report of Columbia Energy Group, to
the Securities and Exchange Commission on Form 10-K, and any Registration
Statement of Columbia Energy Group, relating to the issue of securities to the
public during 1997; 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 1998
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 Columbia Energy Group, 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 Columbia Energy Group, or any affiliate
as a promoter, underwriter, voting trustee, director, officer, employee, or
affiliate.



                                        RYDER SCOTT COMPANY
                                        PETROLEUM ENGINEERS


Houston, Texas
January 22, 1999

<PAGE>   1
                                                                    EXHIBIT 23-B




                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


As independent public accountants, we hereby consent to the incorporation of our
report dated February 11, 1999, included in Columbia Energy Group's 1998 Annual
Report on Form 10-K, into the following previously filed registration
statements:

      1. Form S-8 of Columbia Energy Group (File No. 33-03869)
      2. Form S-8 of Columbia Energy Group (File No. 33-42776)





New York, New York
March 26, 1999

<PAGE>   1
                                                                EXHIBIT 23-C


                                                                February 2, 1999





RE:   EVALUATION OF THE P&NG RESERVES OF COLUMBIA NATURAL RESOURCES (AS OF
      DECEMBER 31, 1998) CONSTANT PRICE AND COST VERSION FOR U.S. SECURITIES
      REPORTING REQUIREMENTS

As independent petroleum and natural gas consultants, we hereby consent to the
filing of this Letter Report in its entirety as an Exhibit to the 1998 Annual
Report of Columbia Energy Group to the Securities and Exchange Commission on
Form 10-K, and any Registration Statement of Columbia Energy Group, relating to
the issue of securities to the public during 1999; to the quotation or
summarization of portions of this Letter Report, subject to our approval of the
related page(s) of the documents(s), in the 10-K, the Prospectus included in
said Registration Statement(s) or the 1998 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
Columbia Energy Group, 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 Columbia Energy Group or any affiliate as a promoter,
underwriter, voting trustee, director, officer, employee, or affiliate.


                                R. N. Johnson, P. Eng.
                                Senior Reservoir Engineer

                                /s/ K. H. Crowther
                                ------------------

                                K. H. Crowther, P. Eng.
                                Executive Vice-President


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