<PAGE>
                                                                   EXHIBIT 10.85


                                                       Service Package No: 34007
                                                                 Amendment No: 0

                         GAS TRANSPORTATION AGREEMENT
                      (For Use under FT-A Rate Schedule)

       THIS AGREEMENT is made and entered into as of the 2 day of November,
2000, by and between TENNESSEE GAS PIPELINE COMPANY, a Delaware Corporation,
hereinafter referred to as "Transporter" and CHATTANOOGA GAS CO, a TENNESSEE
Corporation, hereinafter referred to as "Shipper."  Transporter and Shipper
shall collectively be referred to herein as the "Parties."

                            ARTICLE I - DEFINITIONS

1.1    TRANSPORTATION QUANTITY - shall mean the maximum daily quantity of gas
       which Transporter agrees to receive and transport on a firm basis,
       subject to Article II herein, for the account of Shipper hereunder on
       each day during each year during the term hereof, which shall be 39792
       dekatherms. Any limitations on the quantities to be received from each
       Point of Receipt and/or delivered to each Point of Delivery shall be as
       specified on Exhibit "A" attached hereto.

1.2    EQUIVALENT QUANTITY - shall be as defined in Article I of the General
       Terms and Conditions of Transporter's FERC Gas Tariff.

                          ARTICLE II - TRANSPORTATION

Transportation Service - Transporter agrees to accept and receive daily on a
firm basis, at the Point(s) of Receipt from Shipper or for Shipper's account
such quantity of gas as Shipper makes available up to the Transportation
Quantity, and to deliver to or for the account of Shipper to the Point(s) of
Delivery an Equivalent Quantity of gas.

                ARTICLE III - POINT(S) OF RECEIPT AND DELIVERY

The Primary Point(s) of Receipt and Delivery shall be those points specified on
Exhibit "A" attached hereto.

                                  ARTICLE IV

All facilities are in place to render the service provided for in this
Agreement.

       ARTICLE V - QUALITY SPECIFICATIONS AND STANDARDS FOR MEASUREMENT

For all gas received, transported and delivered hereunder the Parties agree to
the Quality Specifications and Standards for Measurement as specified in the
General Terms and Conditions of Transporter's FERC Gas Tariff Volume No. 1. To
the extent that no new measurement facilities are installed to provide service
hereunder, measurement operations will continue in the manner in which they have
previously been handled. In the event that such facilities are not operated by
Transporter or a downstream pipeline, then responsibility for operations shall
be deemed to be Shipper's.

              ARTICLE VI - RATES AND CHARGES FOR GAS TRANSPORTATION

6.1  TRANSPORTATION RATES - Commencing upon the effective date hereof, the
     rates, charges, and surcharges to be paid by Shipper to Transporter for the
     transportation service provided herein shall be in accordance with
     transporter's Rate Schedule FT-A and the General Terms and Conditions of
     Transporter's FERC Gas Tariff. Except as provided to the contrary in any
     written or electronic agreement(s) between Transporter and Shipper in
     effect during the term of this Agreement, Shipper shall pay Transporter the
     applicable maximum

<PAGE>

                                                       Service Package No: 34007
                                                                 Amendment No: 0


          rate(s) and all other applicable charges and surcharges specified in
          the Summary of Rates in Transporter's FERC Gas Tariff and in this Rate
          Schedule. Transporter and Shipper may agree that a specific discounted
          rate will apply only to certain volumes under the agreement.
          Transporter and Shipper may agree that a specified discounted rate
          will apply only to specified volumes (MDQ, TQ, commodity volumes,
          Extended Receipt and Delivery Service Volumes or Authorized Overrun
          volumes) under the Agreement; that a specified discounted rate will
          apply only if specified volumes are achieved (with the maximum rates
          applicable to volumes above the specified volumes or to all volumes if
          the specified volumes are never achieved); that a specified discounted
          rate will apply only during specified periods of the year or over a
          specifically defined period of time; and/or that a specified
          discounted rate will apply only to specified points, zones, markets or
          other defined geographical area. Transporter and Shipper may agree to
          a specified discounted rate pursuant to the provisions of this Section
          6.1 provided that the discounted rate is between the applicable
          maximum and minimum rates for this service.

     6.2  INCIDENTAL CHARGES - Shipper agrees to reimburse Transporter for any
          filing or similar fees, which have not been previously paid for by
          Shipper, which Transporter incurs in rendering service hereunder.

     6.3  CHANGES IN RATES AND CHARGES - Shipper agrees that Transporter shall
          have the unilateral right to file with the appropriate regulatory
          authority and make effective changes in (a) the rates and charges
          applicable to service pursuant to Transporter's Rate Schedule FT-A,
          (b) the rate schedule(s) pursuant to which service hereunder is
          rendered, or (c) any provision of the General Terms and Conditions
          applicable to those rate schedules. Transporter agrees that Shipper
          may protest or contest the aforementioned filings, or may seek
          authorization from duly constituted regulatory authorities for such
          adjustment of Transporter's existing FERC Gas Tariff as may be found
          necessary to assure Transporter just and reasonable rates.

                      ARTICLE VII - BILLINGS AND PAYMENTS

     Transporter shall bill and Shipper shall pay all rates and charges in
     accordance with Articles V and VI, respectively, of the General Terms and
     Conditions of the FERC Gas Tariff.

                  ARTICLE VIII - GENERAL TERMS AND CONDITIONS

     This Agreement shall be subject to the effective provisions of
     Transporter's Rate Schedule FT-A and to the General Terms and Conditions
     incorporated therein, as the same may be changed or superseded from time to
     time in accordance with the rules and regulations of the FERC.

                            ARTICLE IX - REGULATION

     9.1  This Agreement shall be subject to all applicable and lawful
          governmental statutes, orders, rules and regulations and is contingent
          upon the receipt and continuation of all necessary regulatory
          approvals or authorizations upon terms acceptable to Transporter. This
          Agreement shall be void and of no force and effect if any necessary
          regulatory approval is not so obtained or continued. All Parties
          hereto shall cooperate to obtain or continue all necessary approvals
          or authorizations, but no Party shall be liable to any other Party for
          failure to obtain or continue such approvals or authorizations.

     9.2  The transportation service described herein shall be provided subject
          to Subpart G, Part 284 of the FERC Regulations.

<PAGE>

                                                       Service Package No: 34007
                                                                 Amendment No: 0

               ARTICLE X - RESPONSIBILITY DURING TRANSPORTATION

Except as herein specified, the responsibility for gas during transportation
shall be as stated in the General Terms and Conditions of Transporter's FERC Gas
Tariff Volume No. 1.

                            ARTICLE XI - WARRANTIES

11.1  In addition to the warranties set forth in Article IX of the General Terms
      and Conditions of Transporter's FERC Gas Tariff, Shipper warrants the
      following:

      (a)  Shipper warrants that all upstream and downstream transportation
           arrangements are in place, or will be in place as of the requested
           effective date of service, and that it has advised the upstream and
           downstream transporters of the receipt and delivery points under this
           Agreement and any quantity limitations for each point as specified on
           Exhibit "A" attached hereto. Shipper agrees to indemnify and hold
           Transporter harmless for refusal to transport gas hereunder in the
           event any upstream or downstream transporter fails to receive or
           deliver gas as contemplated by this Agreement.

      (b)  Shipper agrees to indemnify and hold Transporter harmless from all
           suits, actions, debts, accounts, damages, costs, losses and expenses
           (including reasonable attorneys fees) arising from or out of breach
           of any warranty by Shipper herein.

11.2  Transporter shall not be obligated to provide or continue service
      hereunder in the event of any breach of warranty.

                              ARTICLE XII - TERM

12.1  This contract shall be effective as of 2 November, 2000 and shall remain
      in force and effect, unless modified as per Exhibit B, until 1 November,
      2005 ("Primary Term") and on a month to month basis thereafter unless
      terminated by either Party upon at least thirty (30) days prior written
      notice to the other Party; provided, however, that if the Primary Term is
      one year or more, then any rights to Shipper's extension of this Agreement
      after the Primary Term shall be governed by Article III, Section 10.4 of
      the General Terms and Conditions of Transporter's FERC Gas Tariff,
      provided further, if the FERC or other governmental body having
      jurisdiction over the service rendered pursuant to this Agreement
      authorizes abandonment of such service, this Agreement shall terminate on
      the abandonment date permitted by the FERC or such other governmental
      body.

12.2  Any portions of this Agreement necessary to resolve or cash out imbalances
      under this Agreement as required by the General Terms and Conditions of
      Transporter's Tariff shall survive the other parts of this Agreement until
      such time as such balancing has been accomplished; provided, however, that
      Transporter notifies Shipper of such imbalance not later than twelve
      months after the termination of this Agreement.

12.3  This Agreement will terminate automatically upon written notice from
      Transporter in the event Shipper fails to pay all of the amount of any
      bill for service rendered by Transporter hereunder in accord with the
      terms and conditions of Article VI of the General Terms and Conditions of
      Transporter's FERC Gas Tariff.

                             ARTICLE XIII - NOTICE

<PAGE>


                                                       Service Package No: 34007
                                                                 Amendment No: 0


Except as otherwise provided in the General Terms and Conditions applicable to
this Agreement, any notice under this Agreement shall be in writing and mailed
to the post office address of the Party intended to receive the same, as
follows:

             TRANSPORTER:    Tennessee Gas Pipeline Company
                             P.O. Box 2511
                             Houston, Texas 77252-2511

                             Attention: Director, Transportation Control

             SHIPPER:
                NOTICES:     CHATTANOOGA GAS CO
                             C/O ATLANTA GAS LIGHT COMPANY
                             P.O. BOX 4569
                             ATLANTA, GA, USA-303024569

                             Attention: DENISE DOTSON/GINA GUINN

                BILLING:     ATLANTA GAS LIGHT CO
                             1219 CAROLINE STREET, NE

                             ATLANTA, GA, USA-30307

                             Attention: ANDY HAMILTON

or to such other address as either Party shall designate by formal written
notice to the other.

                           ARTICLE XIV - ASSIGNMENTS

14.1    Either Party may assign or pledge this Agreement and all rights and
        obligations hereunder under the provisions of any mortgage, deed of
        trust, indenture, or other instrument which it has executed or may
        execute hereafter as security for indebtedness. Either Party may,
        without relieving itself of its obligation under this Agreement, assign
        any of its rights hereunder to a company with which it is affiliated.
        Otherwise, Shipper shall not assign this Agreement or any of its rights
        hereunder, except in accord with Article III, Section 11 of the General
        Terms and Conditions of Transporter's FERC Gas Tariff.

14.2    Any person which shall succeed by purchase, merger, or consolidation to
        the properties, substantially as an entirety, of either Party hereto
        shall be entitled to the rights and shall be subject to the obligations
        of its predecessor in interest under this Agreement.

                          ARTICLE XV - MISCELLANEOUS

15.1    THE INTERPRETATION AND PERFORMANCE OF THIS CONTRACT SHALL BE IN
        ACCORDANCE WITH AND CONTROLLED BY THE LAWS OF THE STATE OF TEXAS,
        WITHOUT REGARD TO THE DOCTRINES GOVERNING CHOICE OF LAW.

15.2    If any provision of this Agreement is declared null and void, or
        voidable, by a court of competent jurisdiction, then that provision will
        be considered severable at either Party's option; and if the
        severability option is exercised, the remaining provisions of the
        Agreement shall remain in full force and effect.

15.3    Unless otherwise expressly provided in this Agreement or Transporter's
        Gas Tariff, no modification of or supplement to the terms and provisions
        stated in this Agreement shall be


<PAGE>

                                                       Service Package No: 34007
                                                                 Amendment No: 0

     or become effective until Shipper has submitted a request for change
     through PASSKEY and Shipper has been notified through PASSKEY of
     Transporter's agreement to such change.


15.4 Exhibit "A" attached hereto is incorporated herein by reference and made a
     part hereof for all purposes.

     IN WITNESS WHEREOF, the Parties hereto have caused this Agreement to be
duly executed as of the date first hereinabove written.

                    TENNESSEE GAS PIPELINE COMPANY

                    BY: _________________________________
                           Agent and Attorney-in-Fact


                    CHATTANOOGA GAS CO

                    BY: _________________________________

                    TITLE:_______________________________

                    DATE:________________________________
<PAGE>

                                  EXHIBIT "A"
                        TO GAS TRANSPORTATION AGREEMENT
                            DATED November 2, 2000
                                    BETWEEN
                        TENNESSEE GAS PIPELINE COMPANY
                                      AND
                              CHATTANOOGA GAS CO

         CHATTANOOGA GAS CO
         EFFECTIVE DATE OF AMENDMENT: November 2, 2000
         RATE SCHEDULE: FT-A
         SERVICE PACKAGE: 34007
         SERVICE PACKAGE TQ: 39792 Dth

<TABLE>
<CAPTION>
METER    METER NAME                  INTERCONNECT PARTY NAME           COUNTY        ST    ZONE   R/D   LEG   TOTAL-TQ  BILLABLE-TQ
-----------------------------------------------------------------------------------------------------------------------------------
<S>      <C>                         <C>                               <C>           <C>   <C>    <C>   <C>   <C>       <C>
001437   BRAZOS BLOCK 397            TRANSCONTINENTAL GAS PIPE LINE    OFFSHORE-     OT    OO     R     100   1519      1519
                                     CORP                              FEDERAL 704

010503   NEWFIELD-E CAMERON BLK 62A  NEWFIELD EXPLORATION CO           OFFSHORE-     OL    OL     R     800   1034      1034
                                                                       FEDERAL 703

010671   TRIDENT - LOWRY PLT DEHYD   DYNEGY MIDSTREAM SERVICES         CAMERON       LA    OL     R     800   595       595
                                     L.P.

010932   SHIP SHOAL 154 E            DEVON ENERGY PRODUCTION           OFFSHORE-     OL    OL     R     500   6082      6082
                                     COMPANY, L.P.                     FEDERAL 711

011119   SOUTH MARSH ISLAND 61 C     CHEVRON USA INC                   OFFSHORE-     OL    OL     R     500   858       858
                                                                       FEDERAL 707

011220   EUGENE ISLAND 365 A         DEVON ENERGY PRODUCTION           OFFSHORE-     OL    OL     R     500   555       555
                                     COMPANY, L.P.                     FEDERAL 710

011422   SOUTH MARSH ISLAND 260      CALLON PETROLEUM OPERATING        OFFSHORE-     OL    OL     R     800   1403      1403
                                     COMPANY                           FEDERAL 707

011802   SHIP SHOAL 198-J            DEVON ENERGY PRODUCTION           OFFSHORE-     OL    OL     R     500   2363      2363
                                     COMPANY, L.P.                     FEDERAL 711

011911   WHARTON COUNTY TRANS        PG&E TEXAS PIPELINE, L.P.         WHARTON       TX    OO     R     100   2401      2401
         EXCHANGE

011971   CHEVRON - SOUTH MARSH       CHEVRON USA INC                   OFFSHORE-     OL    OL     R     500    556       556
         ISLAND 78-B                                                   FEDERAL 707
</TABLE>
<PAGE>

<TABLE>
<S>       <C>                                     <C>                                  <C>          <C>  <C> <C> <C>   <C>    <C>
012020    TRANSCO - FALFURRIAS TRANSPORT          TRANSCONTINENTAL GAS PIPELINE        JIM WELLS    TX   00  R   100      22     22
                                                  CORP

012024    SAMSON - PRAIRIE-EAST CAMERON BLK 17    SAMSON RESOURCES CO                  OFFSHORE-
                                                                                       FEDERAL 703  OL   0L  R   800    1858   1858

012088    VALERO - MONTE CHRISTO EXCHANGE         PG&E TEXAS PIPELINE, L.P.            HIDALGO      TX   00  R   100    7148   7148

020042    EAST LOBELVILLE TENNESSEE  (75-3201)    EAST TENNESSEE NATURAL GAS           PERRY        TN   01  D   100   20898  20898
                                                  COMPANY

020289    GREENBRIER TENNESSEE #2 (Dual 753101)   EAST TENNESSEE NATURAL GAS           ROBERTSON    TN   01  D   500   18894  18894
                                                  COMPANY

070017    TGP - BEAR CREEK STOR WITHDRAWAL                                             BIENVILLE    LA   01  R   100   13398  13398

                                                                                                  Total Receipt TQ     39792  39792
                                                                                                  Total Delivery TQ    39792  39792
</TABLE>

          NUMBER OF RECEIPT POINTS: 14
          NUMBER OF DELIVERY POINTS: 2

Note: Exhibit "A" is a reflection of the contract and all amendments as of the
amendment effective date.