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                                                                   EXHIBIT 10.10

                                AMENDMENT NO. 1
                                       TO
                             VASTAR RESOURCES, INC.
                           CAPITAL ACCUMULATION PLAN
                           __________________________

Pursuant to the power of amendment reserved therein, the Vastar Resources, Inc.
Capital Accumulation Plan (the "Plan") is hereby amended effective as of the
date of the merger of a subsidiary of BP Amoco p.l.c. ("BPA") with and into
Atlantic Richfield Company.

1.  Paragraph 1.2 of the Plan is amended to read:

     "1.2  "Administrator" means Vastar Resources, Inc."

2.  Paragraph 1.4 of the Plan is amended to read:

     "1.4  Reserved."

3.  Paragraph 2.6 of the Plan is amended to read as follows:

     "2.6  Capital Accumulation Plan Assets

          "(a)  Upon the transfer of an Employee eligible to participate in the
               Plan from a Subsidiary or Affiliate, any assets maintained under
               a capital accumulation plan of such Subsidiary or Affiliate on
               behalf of such Employee will be transferred to the Plan in the
               same investment alternative under which held as of the transfer
               date, and such transferred assets will be subject to the
               investment provisions under Paragraph 6.4, except as provided
               herein:

               (i)   Any assets transferred on behalf of a Member which have
                     been invested in common stock of a Subsidiary or Affiliate
                     will remain so invested, with future dividends being
                     reinvested in such stock under the Member's Account, absent
                     the Member's direction to reinvest such assets pursuant to
                     Paragraph 6.4 of the Plan; provided, however, that any
                     assets converted from the common stock of a Subsidiary or
                     Affiliate to another investment alternative under the Plan
                     may not be reinvested in common stock of a Subsidiary or
                     Affiliate.

               (ii)  Vastar Resources, Inc. common stock attributable to Company
                     contributions shall be invested in accordance with
                     Paragraph 6.3 of the Plan.

               (iii) Common stock of a Subsidiary or Affiliate held by the Plan
                     shall be subject to the sale and voting provisions of
                     Section 6."

4.  A new Subparagraph (c) is added to Paragraph 6.2 of the Plan to read as
follows:

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     "(c)  In order to convert any Atlantic Richfield common stock into BPA
           American Depositary Receipts ("ADRs"), effective as of dates
           determined in writing by the Senior Vice President, Human Resources,
           Atlantic Richfield Company, trading in Atlantic Richfield common
           stock or BPA ADRs will not be allowed by the Plan. Shares of Atlantic
           Richfield common stock may not be converted into any shares that are
           not traded on the New York Stock Exchange."

5.  A new Paragraph 6.14 is added to the Plan to read as follows:

     "6.14 Conversion of Atlantic Richfield Company Common Stock

           Effective with the merger of Atlantic Richfield Company and a
           subsidiary of BPA, all shares and partial shares of Atlantic
           Richfield Company common stock shall be converted to BPA ADRs."

6.   Paragraph 9.3 of the Plan is amended to read as follows:

     "9.3  Loan Amount

          (a)  The maximum loan shall be the lesser of one half of the Member's
               Account or $50,000 (reduced by the highest balance, at any
               specific time, of any outstanding loan or loans during the
               preceding 12 months from this Plan).

          (b)  A loan must be in cash, in increments of $100 and in an amount
               not less than $1,000.

          (c)  The maximum loan amount shall be reduced to the extent necessary
               to prevent each installment of the loan payment, including
               principal and interest, when added to installments under any
               outstanding loan under the Plan, from exceeding 25 percent of a
               Member's biweekly earnings.

          (d)  The loan amount may not exceed the lesser of (i) the amount of
               the Member's Contributions, Elective Deferrals and Company
               Contributions under the Atlantic Richfield Savings Plans II and
               III made prior to July 1, 1988 (including assets which originated
               in the Atlantic Richfield Employee Stock Ownership Plan) and
               earnings thereon at the time the loan is made, or (ii) the amount
               of the security, as described hereafter, for the loan.

          (e)  For purposes of this Paragraph 9.3, the value of Common Stock, or
               any other investment alternative will be determined on the
               Valuation Date immediately preceding the date the loan
               application is received by the Administrator under rules
               established by the Administrator."

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7.  Paragraph 10.1 is amended to read as follows:

     "10.1  Capital Accumulation Plan Administrator

            The Plan shall be administered by the Company acting through one or
            more of its executive officers."

8.   All references in the Plan to the "Capital Accumulation Plan Administrative
     Committee" (or to "Committee" when referring to the Capital Accumulation
     Plan Administrative Committee) are amended to read "Administrator".


Executed effective as of April 18, 2000.

ATTEST:                                   VASTAR RESOURCES, INC.

/s/ A. Shawn Noonan                       By: /s/ Jeffrey M. Bender
_________________________________            ____________________________
A. Shawn Noonan                                   Jeffrey M. Bender
General Tax Officer                               Vice President
                                                  Human Resources


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