AMENDATORY AGREEMENT NO. 3
                  TO THE AGREEMENT FOR THE SALE AND PURCHASE OF
                               NATURAL GAS BETWEEN
                          CHUGACH ELECTRIC ASSOCIATION
                                       AND
                             SHELL WESTERN E&P INC.

THIS  AGREEMENT is made and entered into this 14th day of October,  1996, by and
between Shell Western E&P Inc., a  corporation  organized  under the laws of the
State of Delaware ("SWEPI"),  and Chugach Electric Association,  Inc., an Alaska
nonprofit electric cooperative membership corporation ("Chugach").

WHEREAS,  SWEPI owns a one-third  working  interest in the natural gas  reserves
underlying the Beluga River Unit, Cook Inlet, Alaska; and

WHEREAS, SWEPI, as Seller, and Chugach, as Buyer, have entered into an Agreement
for the Sale and  Purchase of Natural Gas dated  April 25,  1989,  as amended on
October 1, 1989 and June 20,  1990,  and as  supplemented  on  November  2, 1990
("Natural Gas Agreement"); and

WHEREAS,  SWEPI  has  entered  into a  Purchase  and  Sale  Agreement  with  the
Municipality  of Anchorage d/b/a Municipal Light & Power ("ML&P") dated April 9,
1996 ("PSA"), as amended by the Supplemental Agreement dated September 24, 1996,
whereby  SWEPI  has  agreed  to sell and ML&P has  agreed  to  purchase  SWEPI's
one-third working interest in the Beluga River Unit effective September 1, 1996;
and

WHEREAS,  by letter dated  December 4, 1989,  the Alaska  Department  of Natural
Resources  ("ADNR")  agreed  to use the  price  for the gas  established  in the
Natural  Gas  Agreement  as the royalty  value for the State's  share of royalty
production pursuant to AS 38.05.180(aa); and

WHEREAS, SWEPI desires to assign the Natural Gas Agreement to ML&P; and

WHEREAS,  Chugach desires to reduce future commercial interaction between itself
and ML&P with  respect to the rights and  obligations  of the parties  under the
Natural Gas Agreement; and

WHEREAS,  SWEPI and  Chugach  desire to amend  the terms and  conditions  of the
Natural Gas Agreement in order to permit the assignment of such amended  Natural
Gas Agreement to ML&P with the consent of Chugach.

NOW,  THEREFORE,  SWEPI and Chugach, in consideration of the mutual promises set
forth herein, agree as follows:







1.       All references  hereunder to Sections,  Subsections,  or Exhibits shall
         mean such Section,  Subsection, or Exhibit contained in the Natural Gas
         Agreement.

2.       This  Agreement  amending the terms and  conditions  of the Natural Gas
         Agreement  shall become  effective only upon the Closing of the PSA, as
         such term is  defined  in the PSA or any  amendment  thereto,  and upon
         approval of this  Agreement by the Alaska Public  Utilities  Commission
         ("APUC").  In the event the Closing  does not occur under the terms and
         conditions of the PSA, the Natural Gas  Agreement  will not be assigned
         by SWEPI to ML&P and this  Agreement  amending the terms of the Natural
         Gas Agreement shall be void, ab initio.

3.       Chugach may continue  its status as an  intervenor  in Docket  U-96-36
         which is  pending  before  the APUC,  but shall not take any  position
         before  the APUC  which  would  oppose  the  proposed  sale of SWEPI's
         one-third  interest  in the  Beluga  River  Unit to ML&P or any  other
         position which would cause the APUC to condition the terms of the PSA.
         Chugach shall be free to argue to the APUC in Docket  U-96-36 that the
         APUC should establish a separate docket to investigate the appropriate
         limitations  and  requirements,  if any,  that  should  govern  ML&P's
         internal  accounting for and pricing of gas used to generate  electric
         power.

4.       Chugach  shall give its  consent to the  assignment  of the Natural Gas
         Agreement,  as  amended  herein  to ML&P,  pursuant  to  Section  10.6.
         Assignment of the Natural Gas Agreement,  as amended by this Agreement,
         will be without a release of SWEPI's  obligations under the Natural Gas
         Agreement,  and shall not relieve SWEPI of its  obligations  to Chugach
         under the Natural Gas Agreement.

5.       In Section 1.15,  delete the reference to  "Administrator of the Rural
         Electrification  Administration,   an  agency  of  the  United  States
         Department of Agriculture, and Spokane Bank for Cooperatives."

6.       In Section 4.4, SWEPI  acknowledges that gas committed to Chugach under
         the Natural Gas Agreement enjoys a priority over any gas that ML&P will
         acquire from SWEPI, to the extent that ML&P uses or otherwise  disposes
         of  such  gas  for  sale  or  to  generate   electric  power.   Chugach
         acknowledges  that SWEPI retains the rights  specified in Article II of
         the  Natural  Gas  Agreement  and that the  priority  for the  contract
         specified in Exhibit A of the Natural Gas  Agreement is not affected by
         this Agreement.

7.       SWEPI  shall be deemed to decline  any offer by  Chugach,  pursuant  to
         Section 5.5, to sell any volume of gas not previously  committed  under
         the Natural Gas Agreement.

8.       Under Section 5.5(C), if ARCO Alaska,  Inc. ("ARCO") either declines or
         does not  decline to permit  Chugach  the right to take as Third  Party
         Replacement  Gas any gas then  committed to Chugach  under the Sale and
         Purchase of Natural Gas  Agreement  dated April 21, 1989,  between ARCO
         and Chugach ("ARCO  Contract"),  SWEPI shall be deemed to have acted in
         the same manner as ARCO. In this respect, Chugach shall






         provide to SWEPI on a timely basis a copy of the communications between
         ARCO and Chugach pertaining to this Third Party Replacement gas matter.
         Notwithstanding  the above, SWEPI may decline to permit Chugach to take
         Third  Party  Replacement  gas to the  extent  that ML&P  requires  the
         necessary  deliverability  to  satisfy  ML&P's  actual  and  verifiable
         requirements  for  deliverability   necessary  for  the  generation  of
         electric power by ML&P.

9.       Except for differences in excess deliverability  provided by producers
         for gas supplied under Sections 5.5(C), 5.7(B) or 5.7(C),  pursuant to
         Section 5.6,  Chugach shall have met its obligation to SWEPI and SWEPI
         shall have met its  obligation  to Chugach  if Chugach  purchases  and
         takes from SWEPI and SWEPI sells and  delivers to Chugach  exactly the
         same volumes as Chugach  purchases  and takes from ARCO and ARCO sells
         and  delivers to Chugach  under the ARCO  Contract.  In this  respect,
         Chugach  shall  provide  to  SWEPI  on a  timely  basis  a copy of the
         communications  between  Chugach and ARCO  pertaining to the volume of
         gas purchased and taken under the ARCO Contract.

10.      Under Sections 5.7(B) and 5.7(C), if ARCO declines or does not decline
         to  permit  Chugach  to take  gas in  excess  of the  then  applicable
         deliverability requirement ("excess delivery gas") under its Contract,
         then SWEPI  shall be deemed to have acted in the same  manner as ARCO.
         In this  respect,  Chugach  shall provide to SWEPI on a timely basis a
         copy of the  communications  between  ARCO and Chugach  pertaining  to
         excess delivery gas.  Notwithstanding  the above, SWEPI may decline to
         permit  Chugach to take  excess  delivery  gas to the extent that ML&P
         requires such gas to satisfy ML&P's actual and verifiable requirements
         for  deliverability  necessary for the generation of electric power by
         ML&P.

11.      The reference in Section 5.5(C) to "then  existing other  commitments",
         the reference in Section 5.7(B) to "the deliverability is not committed
         to the performance of any other contract", and the reference in Section
         5.7(C) to "within  the  operational  and  contractual  limitations  and
         constraints to which SWEPI is subject" shall, subject to the provisions
         of Section 4.4, as described  in Section 6 of this  Agreement,  include
         satisfaction   of  ML&P's  actual  and  verifiable   requirements   for
         deliverability necessary for the generation of electric power by ML&P.

12.      Under  Section  6.1,  SWEPI  shall be deemed to have  acted in the same
         manner as ARCO reacts under the ARCO  Contract as to whether the annual
         Forecast is  unreasonably  high or low.  "Va" in Section 6.1 under this
         Agreement  shall be equal to "Va" under the ARCO Contract,  as the same
         shall be  determined  and  resolved by ARCO and Chugach  under the ARCO
         Contract.

13.      In  complying  with  Section 6.1,  any records  which  Chugach,  in the
         ordinary course of doing business,  would not make public or provide to
         a  competitor  shall not be required to be furnished to SWEPI under the
         terms of the Natural Gas Agreement.  Further, SWEPI shall not knowingly
         obtain or seek to obtain such information from ARCO, Chevron, Marathon,
         or their respective successors or assigns of their respective contracts
         with






         Chugach.

14.      Under  Sections  6.2 and 6.3,  SWEPI  shall be deemed to have given its
         consent for Chugach to take the actions referenced in such Sections, if
         ARCO has given its consent  for Chugach to take the actions  referenced
         in such Sections under the ARCO  Contract.  SWEPI may elect to give its
         consent for Chugach to take the actions referenced in such Sections.

15.      In  Section  6.5,  substitute  "Chugach  shall  not take any  action to
         displace  gas  provided  by SWEPI which it has not taken under the ARCO
         Contract or under the Sale and Purchase of Natural Gas Agreement  dated
         April 27, 1989,  between  Chevron and Chugach  ("Chevron  Contract") to
         displace gas provided by ARCO or Chevron, respectively" for the proviso
         in the last three lines of Section 6.5.

16.      In Section 7.3, add the following  sentence at the end of the Section:
         "Any Period 2 Volume remaining to be taken on December 31, 2013, shall
         be taken by no later than December 31, 2015."

17.      Any adjustment to the price of gas delivered by SWEPI under the Natural
         Gas  Agreement  due to Btu  adjustment  under Section 7.10 or Exhibit D
         shall be identical to the price  adjustment,  if any, as the same shall
         be determined and resolved by ARCO under the ARCO Contract.

18.      As long as ARCO is the Operator of the Beluga River Unit, ARCO shall be
         the  dispatching  agent for SWEPI under the Natural Gas Agreement,  and
         shall  be  responsible  for  complying  with  dispatching  requests  of
         Chugach.  Neither  SWEPI nor ML&P nor  Chugach or their  successors  or
         assigns will become  Operator of the Beluga River Unit,  nor will SWEPI
         or ML&P become the  dispatching  agent  responsible  for complying with
         dispatching requests of Chugach.

19.      In Section  10.1,  add the words  "except in the case of bad faith" to
         the end of the second sentence.

20.      For purposes of Section 10.2, the  Municipality of Anchorage shall not
         be considered as a governmental agency of competent jurisdiction.

21.      Under Section 10.9,  the right of access to property of the other shall
         be limited to access by Chugach to the Beluga River Unit, and shall not
         give either Chugach or SWEPI the right to access of the property of the
         other.

22.      In Section  10.11,  the  access to the  records of a Party by the other
         Party  shall be limited to  records of the  Operator/Dispatcher  of gas
         from the Beluga River Unit.

23.      In Section 10.13,  substitute "Alaska Public Utilities Commission" for
         "approved by each entity whose approval is a Necessary Approval".





24.      With respect to Exhibit D,  Paragraph B. III (b), SWEPI shall be deemed
         to have agreed to any substitute  indices and/or  commodities  required
         under  Paragraph  B as ARCO and  Chevron  shall agree to under the ARCO
         Contract and the Chevron Contract,  respectively. In the event ARCO and
         Chevron  do not act in the  same  manner  with  respect  to  substitute
         indicies and/or commodities,  SWEPI may elect to act in the same manner
         as either ARCO or Chevron.

25.      Nothing in this Agreement  shall affect SWEPI's rights and  obligations
         under the Beluga River Unit Joint  Operating  Agreement  dated April 1,
         1962, as amended.  SWEPI  represents that there is nothing in the Joint
         Operating   Agreement   which  prevents   SWEPI  from   performing  its
         obligations under this Agreement.

26.      Exhibit E shall be deleted in its entirety and the attached  Exhibit E
         shall be substituted therefor.

27.      Except for the foregoing  amendments to the Natural Gas Agreement,  all
         other terms and conditions of the Natural Gas Agreement shall remain in
         full force and effect.

28.      In Section 7.6, add the following as  subsection  (F): "(F) SWEPI shall
         notify  Chugach  of any  notice  or  demand  received  from the  Alaska
         Department of Revenue, or successor agency, which assesses Reimbursable
         Tax or Taxes  with  respect  to the gas  delivered  to Chugach by SWEPI
         under the Natural Gas  Agreement as amended  herein.  At the request of
         Chugach, SWEPI shall pay such assessment under protest.

IN WITNESS  WHEREOF,  the parties  hereto have executed this Agreement as of the
date first above written.


CHUGACH ELECTRIC ASSOCIATION,                            SHELL WESTERN E&P INC.
INC.


By:  /s/ Eugene N. Bjornstad                             By:  /s/ Steve Merritt
Its:  General Manager                                     Its: Attorney-in-Fact