FIRST AMENDMENT TO AMENDED AND
                    RESTATED AGREEMENT OF LIMITED PARTNERSHIP
                                       OF
                   NOARK PIPELINE SYSTEM, LIMITED PARTNERSHIP


         This FIRST  AMENDMENT  TO AMENDED  AND  RESTATED  AGREEMENT  OF LIMITED
PARTNERSHIP  OF  NOARK  PIPELINE  SYSTEM,   LIMITED   PARTNERSHIP  (this  "First
Amendment")  dated as of June 18,  1998 amends that certain Amended and Restated
Agreement of Limited  Partnership of NOARK Pipeline System,  Limited Partnership
dated as of January 12,  1998 (the "Partnership Agreement") between Southwestern
Energy Pipeline  Company,  as a general  partner,  and Enogex Arkansas  Pipeline
Corporation, as a general partner and a limited partner.  Capitalized terms used
herein and not defined  herein shall have the meanings  assigned  thereto in the
Partnership Agreement.

         In consideration of the mutual promises made herein, and for other good
and  valuable  consideration  the  receipt and  sufficiency  of which are hereby
acknowledged, the Partners hereby agree as follows:

         1. The definition of "Existing Loans" in Section 1.1 of the Partnership
Agreement is hereby amended in its entirety to read as follows:

         " "Existing  Loans" means the NOARK Debt, and any  subsequent  loans to
         the Partnership or any NOARK Related Entity replacing the then existing
         principal  balance of the NOARK Debt,  or the then  existing  principal
         balance of such subsequent loans, as applicable."

         2. The  definition  of "NOARK  Debt" in Section 1.1 of the  Partnership
Agreement is hereby amended by inserting at the end thereof, the following:

         "; provided,  however,  that from and after June 18,  1998 "NOARK Debt"
         shall mean the Finance  Notes,  and shall  exclude for all  purposes of
         this  Agreement  the debt incurred by the  Partnership  pursuant to the
         terms of that certain Loan Agreement  dated as of June 1,  1998 between
         the Partnership and NOARK Pipeline Finance, L.L.C., an Oklahoma limited
         liability company."

         3.  Section  1.1 of the  Partnership  Agreement  is hereby  amended  by
inserting the following definitions:

         "Defaulting  Guarantor"  shall have the meaning assigned thereto in the
         Indenture.

         "EAPC  Allocated   Existing  Loans"  shall  mean,  at  any  time  after
         indebtedness  is  incurred  pursuant  to the last  sentence  of Section
         3.5(b) hereof,  (i) 40% of the Existing Loans  immediately prior to the
         incurrence of such  indebtedness  and the  application  of the 



         proceeds thereof;  less, if and only if Southwestern  Energy Company is
         the Defaulting  Guarantor (as defined in the Indenture),  the principal
         amount of Finance Notes  redeemed upon  application  of the proceeds of
         such  indebtedness and (ii) if and only if Southwestern  Energy Company
         is the Defaulting Guarantor,  the indebtedness incurred pursuant to the
         last sentence of Section 3.5(b) hereof, and any subsequent loans to the
         Partnership  replacing the principal  balance  thereof at the time such
         subsequent loans are made.

         "Enogex  Guaranty"  shall  have the  meaning  assigned  thereto  in the
         Indenture.

         "Finance  Notes"  shall mean the 7.15%  Notes Due 2018  issued by NOARK
         Pipeline Finance,  L.L.C. in the original aggregate principal amount of
         $80,000,000 pursuant to the Indenture.

         "Indenture"  shall mean the Indenture dated as of June 1,  1998 between
         the  NOARK  Pipeline  Finance,  L.L.C.  and The  Bank of New  York,  as
         trustee, as it may be amended or supplemented from time to time.

         "Non-Defaulting  Guarantor"  shall have the meaning assigned thereto in
         the Indenture.

         "Southwestern  Guaranty" shall have the meaning assigned thereto in the
         Indenture.

         "SWPL  Allocated   Existing  Loans"  shall  mean,  at  any  time  after
         indebtedness  is  incurred  pursuant  to the last  sentence  of Section
         3.5(b)  hereof,  the sum of (i) 60% of the Existing  Loans  immediately
         prior to the incurrence of such indebtedness and the application of the
         proceeds  thereof,  less, if and only if Enogex Inc. is the  Defaulting
         Guarantor  (as  defined  in the  Indenture),  the  principal  amount of
         Finance  Notes  redeemed  upon  application  of the  proceeds  of  such
         indebtedness  and (ii) if and only if  Enogex  Inc.  is the  Defaulting
         Guarantor,  the indebtedness  incurred pursuant to the last sentence of
         Section 3.5(b)  hereof,  and any  subsequent  loans to the  Partnership
         replacing the  principal  balance  thereof at the time such  subsequent
         loans are made.

         4. Subsection (b) of Section 3.5 of the Partnership Agreement is hereby
amended as follows:

         (i) by inserting  the words "by the  Partnership  (including  any NOARK
Related Entity)"  immediately after the words  "indebtedness for borrowed money"
in the first line thereof; and

         (ii) by inserting  at the end of said  subsection  (b),  the  following
sentence:

         "Notwithstanding  the  foregoing,  (i) if  Southwestern  Energy Company
         shall  be  a  Defaulting   Guarantor   and  Enogex  Inc.   shall  be  a
         Non-Defaulting  Guarantor,  the Partnership,  at the direction of EAPC,
         may incur  indebtedness  for borrowed  money (x) upon a declaration  of
         acceleration  of the Finance  Notes  pursuant to Section  6.1(b) of the
         Indenture,  in a principal  amount  equal to the  Guaranteed  Principal
         Amount (as  defined  in the Enogex  Guaranty)  or (y)  otherwise,  in a
         principal  amount  equal to the  Redemption

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         Price (as defined in the  Indenture)  applicable  to the  redemption of
         Finance Notes in an aggregate  principal amount equal to the Guaranteed
         Principal  Amount (as  defined in the  Enogex  Guaranty),  in each case
         without the consent of the  SuperMajority in Interest of Partners,  and
         the proceeds of such indebtedness  shall be applied on behalf of Enogex
         Inc. to the payment of the Finance Notes upon  acceleration  thereof or
         to the  redemption of Finance Notes  pursuant to Section  3.1(b) of the
         Indenture, as applicable, and (ii) if Enogex Inc. shall be a Defaulting
         Guarantor and  Southwestern  Energy  Company shall be a  Non-Defaulting
         Guarantor,  the  Partnership  may,  at the  direction  of  SWPL,  incur
         indebtedness  for borrowed money (x) upon a declaration of acceleration
         of the Finance Notes pursuant to Section 6.1(b) of the Indenture,  in a
         principal  amount equal to the Guaranteed  Principal Amount (as defined
         in the Southwestern  Guaranty) or (y) otherwise,  in a principal amount
         equal to the Redemption Price (as defined in the Indenture)  applicable
         to the  redemption  of Finance Notes in an aggregate  principal  amount
         equal  to  the   Guaranteed   Principal   Amount  (as  defined  in  the
         Southwestern  Guaranty),  in  each  case  without  the  consent  of the
         SuperMajority  in  Interest  of  Partners,  and  the  proceeds  of such
         indebtedness shall be applied on behalf of Southwestern  Energy Company
         to the payment of the Finance Notes upon acceleration thereof or to the
         redemption  of  Finance  Notes   pursuant  to  Section  3.1(b)  of  the
         Indenture;  provided that any  indebtedness  incurred  pursuant to this
         sentence  without  the  consent of the  SuperMajority  in  Interest  of
         Partners  shall  be  unsecured,  shall be  non-recourse  to each of the
         Partners  (unless with respect to either  Partner,  such Partner  shall
         otherwise  consent in writing)  and shall not  contain  any  covenants,
         agreements  or provisions  which would in any material  respect be more
         restrictive on the Partnership and the NOARK Related Entities and their
         respective  businesses  and affairs than the  covenants,  agreements or
         provisions of the Indenture  and the Finance  Notes.  In the event that
         EAPC directs the Partnership to incur  indebtedness as described in the
         preceding  sentence,  (i) EAPC,  on behalf of the Partnership,  and the
         Partnership  are  hereby  authorized  to  take  such  action  as may be
         reasonably  required  in  order  for  the  Partnership  to  incur  such
         indebtedness  in  conformity  with the  requirements  of the  preceding
         sentence,  without any further action by the Partners or the Management
         Committee and (ii) SWPL shall take all such actions and execute any and
         all  documents  reasonably  required by it as a general  partner of the
         Partnership to facilitate the  incurrence of such  indebtedness  by the
         Partnership;  provided  that SWPL  shall not  incur  any  liability  in
         respect  thereof.  In the event that SWPL  directs the  Partnership  to
         incur indebtedness as described in the preceding sentence, (i) SWPL, on
         behalf of the Partnership, and the Partnership are hereby authorized to
         take  such  action  as may be  reasonably  required  in  order  for the
         Partnership  to  incur  such   indebtedness   in  conformity  with  the
         requirements  of the second  preceding  sentence,  without  any further
         action by the Partners or the Management  Committee and (ii) EAPC shall
         take all such  actions  and execute  any and all  documents  reasonably
         required by it as a general  partner of the  Partnership  to facilitate
         the incurrence of such  indebtedness by the Partnership;  provided that
         EAPC shall not incur any liability in respect thereof.

         5. Section 4.2(c) of the Partnership Agreement is hereby amended in its
entirety to read as follows:

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         (c)  The  Partners  agree  that  (i)  prior  to the  incurrence  of any
         indebtedness  pursuant  to the last  sentence  of Section  3.5(b),  the
         Existing  Loans,  including  applicable  interest,  shall be  repaid as
         follows:  (x) sixty  percent  (60%) of the  Existing  Loans,  including
         applicable  interest,  shall be  repaid  out of any  amounts  otherwise
         distributable  to SWPL,  before taking into account debt service on the
         Existing Loans, under this Agreement and (y) forty percent (40%) of the
         Existing Loans,  including applicable interest,  shall be repaid out of
         any amounts otherwise distributable to EAPC, before taking into account
         debt service on the Existing Loans, under this Agreement, and (ii) from
         and after  the  incurrence  of any  indebtedness  pursuant  to the last
         sentence of Section 3.5(b),  the Existing Loans,  including  applicable
         interest,  shall be repaid as follows:  (x) the SWPL Allocated Existing
         Loans,  including  applicable  interest,  shall  be  repaid  out of any
         amounts  otherwise  distributable  to SWPL,  before taking into account
         debt service on the Existing  Loans,  under this  Agreement and (y) the
         EAPC Allocated Existing Loans, including applicable interest,  shall be
         repaid  out of any  amounts  otherwise  distributable  to EAPC,  before
         taking into  account debt  service on the  Existing  Loans,  under this
         Agreement.  If such amounts  referred to in clause (i) of the preceding
         sentence are insufficient to pay a Partner's percentage share (i.e. 60%
         or 40% as set forth above) of the debt  service on the Existing  Loans,
         including  applicable  interest,  in accordance with their terms,  then
         such Partner shall be  responsible  to contribute to the capital of the
         Partnership amounts sufficient to pay its percentage share (i.e. 60% or
         40% as set forth  above) of the debt  service  on the  Existing  Loans,
         including  applicable  interest,  and shall do so upon  notice from the
         Project  Leader.  If such  amounts  referred  to in clause  (ii) of the
         preceding sentence are insufficient to pay the debt service on the SWPL
         Allocated  Existing Loans or the EAPC Allocated Existing Loans, in each
         case including applicable  interest,  in accordance with its respective
         terms,  then SWPL or EAPC, as the case may be, shall be  responsible to
         contribute to the capital of the Partnership  amounts sufficient to pay
         the debt  service  on the  SWPL  Allocated  Existing  Loans or the EAPC
         Allocated  Existing  Loans,  as  applicable,  including  in  each  case
         interest thereon,  and shall do so upon notice from the Project Leader.
         Notwithstanding the foregoing, if either SWPL or EAPC obtains knowledge
         that it is responsible to contribute to the capital of the  Partnership
         pursuant to this Section  4.2(c),  then such Partner shall be obligated
         to make such  contribution  of capital to the  Partnership  on a timely
         basis  notwithstanding  the fact that the Project  Leader has not given
         notice to such Partner as contemplated hereby. Capital Contributions by
         the  Partners  pursuant  to this  Section  4.2(c)  shall  not alter the
         Partnership  Percentages  of the Partners.  Default by a Partner in the
         making  of such  Capital  Contributions  shall  cause it to be deemed a
         Delinquent Partner subject to the provisions of Section 4.3 hereof.

         6. Section 4.2(d) of the Partnership Agreement is hereby amended in its
entirety to read as follows:

         (d) Notwithstanding anything to the contrary in Section 4.2(c) above or
         elsewhere in this Agreement, it is understood and agreed that the terms
         of any Existing Loans may in the future (but do not currently)  provide
         that the amortization of the principal amount thereof shall be borne or
         allocated  in a manner  different  from the  percentages  set  forth in

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         Section  4.2(c) or any Partner  may direct the Project  Leader to apply
         amounts of  Partnership  cash otherwise  distributable  to such Partner
         (except  amounts  to be paid to other  Partners  pursuant  to the other
         provisions  of this  Agreement)  to the  repayment or prepayment of the
         principal  amount  of the  Existing  Loans  in  excess  of the  amounts
         required to be repaid under the terms of the Existing  Loans,  provided
         such  Partner  bears all costs and  penalties of doing so. In addition,
         either  Partner  may elect to redeem  from such  Partner's  own funds a
         portion of the Finance Notes  pursuant to Section 3.1 of the Indenture.
         Consequently,  a  Partner  may  thereby  pay  or  bear  more  than  its
         attributable  percentage of the principal  amount of the Existing Loans
         to be repaid.  In such event,  the percentages of the then  outstanding
         principal amount of the Existing Loans payable out of the distributable
         amounts  attributable to the Partners set forth in Section 4.2(c) shall
         be adjusted as appropriate  to reflect the resulting  percentage of the
         aggregate  outstanding  principal  amount of the  Existing  Loans  then
         attributable to each Partner.

         7. Section 5.3 of the  Partnership  Agreement is hereby  amended in its
entirety to read as follows:

                  5.3.  Special  Interest  Expense.   The  Partnership  interest
         expense  deductions  incurred with regard to the Existing Loans and the
         Finance Notes as referenced in Section 4.2(c) shall be allocated to the
         Partners as follows:

                  (i) prior to the  incurrence of any  indebtedness  pursuant to
                  the last  sentence of Section  3.5(b),  60% to SWPL and 40% to
                  EAPC; and

                  (ii) following the incurrence of any indebtedness  pursuant to
                  the last sentence of Section 3.5(b), the Partnership  interest
                  expense deductions  incurred with regard to the SWPL Allocated
                  Existing Loans shall be allocated to SWPL and the  Partnership
                  interest expense  deductions  incurred with regard to the EAPC
                  Allocated Existing Loans shall be allocated to EAPC.

         In the event the  percentages of the outstanding  principal  amounts of
         the  Existing   Loans   payable  out  of  the   distributable   amounts
         attributable  to each Partner are adjusted  pursuant to Section 4.2(d),
         the foregoing percentages shall be subject to adjustment to reflect the
         same  percentages as the  percentages  established  pursuant to Section
         4.2(d).

         8. The Partnership  Agreement,  as amended hereby, shall remain in full
force and effect and is hereby ratified, approved and confirmed in all respects.

         9. From and after the date hereof,  each  reference in the  Partnership
Agreement to "this Agreement," "hereof," or "hereunder" or words of like import,
and all  references  to the  Partnership  Agreement  in any and all  agreements,
instruments, documents, notes, certificates and other writings of every kind and
nature  shall be deemed  to mean the  Partnership  Agreement,  as  modified  and
amended by this First Amendment.

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         10. THE  PROVISIONS  OF THIS FIRST  AMENDMENT  SHALL BE GOVERNED BY AND
CONSTRUED  AND  ENFORCED  IN  ACCORDANCE  WITH THE LAWS OF THE STATE OF ARKANSAS
(EXCLUDING ANY  CONFLICTS-OF-LAW  RULE OR PRINCIPLE THAT MIGHT REFER SAME TO THE
LAWS OF ANOTHER  JURISDICTION),  EXCEPT TO THE EXTENT THAT SAME ARE  MANDATORILY
SUBJECT TO THE LAWS OF ANOTHER  JURISDICTION  PURSUANT TO THE LAWS OF SUCH OTHER
JURISDICTION.

         11. This First Amendment may be executed in multiple counterparts, each
of  which  shall  be  deemed  an  original  agreement,  and all of  which  shall
constitute  one  agreement,   by  each  of  the  parties  hereto  on  the  dates
respectively  indicated in the signatures of said parties,  notwithstanding that
all  of  the  parties  are  not  signatories  to the  original  or to  the  same
counterpart, to be effective as of the day and year hereinabove set forth.

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        IN WITNESS WHEREOF,  the Partners have executed this First Amendment on
the date first set forth above.

                                       GENERAL PARTNERS:

                                       ENOGEX ARKANSAS PIPELINE CORPORATION


                                       By:                                     
                                       Name:    E. Keith Mitchell
                                       Title:   Vice President


                                       SOUTHWESTERN ENERGY PIPELINE COMPANY


                                       By:                                      
                                       Name:    Stanley D. Green
                                       Title:   Executive Vice President-Finance
                                                & Corporate Development


                                       LIMITED PARTNER:

                                       ENOGEX ARKANSAS PIPELINE CORPORATION


                                       By:                                     
                                       Name:    E. Keith Mitchell
                                       Title:   Vice President





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