Document:

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                                                                   EXHIBIT 10.40

                          SOFTWARE LICENSE AGREEMENT

     This Agreement (the "Agreement") is entered into effective as of October
27, 1999, by and between Atlantic Richfield Company, a Delaware corporation
("Licensor"), and Vastar Resources, Inc., a Delaware corporation ("Licensee"),
each being individually a "Party" and collectively the "Parties."

W I T N E S S E T H:

WHEREAS, Licensor and Licensee are both engaged in the business of oil and gas
exploration. Licensor formed Licensee in 1993 (corporate entity) and currently
has greater than an 80% ownership interest in Licensee. On October 1, 1993,
Licensor assigned and conveyed to Licensee, certain assets for use in Licensee's
independent operations. In addition to the assets which were conveyed to
Licensee, Licensor and Licensee also entered into various agreements on October
1, 1993, and from time to time since then, in which Licensor licensed certain
software and other intellectual property rights to Licensee, and Licensor agreed
to provide certain services and support to Licensee; and

WHEREAS, since October 1, 1993, Licensee has been in possession of or had access
to, or has subsequently been in possession of or had access to, certain software
relative to accounting, administration, marketing, and personnel, all as
described in greater detail in the attached Exhibit "A" ("Nontechnical
Software") and certain software relative to exploration and engineering, all as
described in greater detail in the attached Exhibit "B" ("Technical Software").
Nontechnical Software and Technical Software are together hereinafter referred
to as the "Software." The Software which is the subject of this Agreement was
originally paid for in whole or part by Licensee. Since October 1, 1993,
Licensee has utilized said funded Software for Licensee's internal operating
purposes with Licensor's knowledge and consent, and with Licensor providing
maintenance and support of some of the Software; and

WHEREAS, Licensee desires to continue utilizing the Software for its own
internal operating purposes and both Licensor and Licensee believe it is in
their respective best interests to enter into an agreement which specifies
Licensee's right to use the Software and have possession of the corresponding
source code.

NOW, THEREFORE, in consideration of the premises and mutual covenants of this
Agreement, the Parties agree as follows:

1. LICENSE

With regard to the nontechnical software listed in Exhibit "A," Licensor hereby
grants to Licensee, a perpetual, irrevocable, nonexclusive, nonassignable,
license to use the software for the benefit of Licensee's business.  Said
license to use the software includes a perpetual, irrevocable right to modify
the software and thereby make derivative works and/or other improvements to the
software.  Licensor acknowledges that Licensee shall exclusively own all rights
in any such improvements including all copyrights therein.  The Parties further
agree that the subject license does not include any right of the Licensee to
sell or sublicense the software.

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With regard to the technical software listed in Exhibit "B," Licensor hereby
grants to Licensee, a perpetual, nonexclusive, nonassignable, license to use the
software for the benefit of Licensee's business. Said license to use the
software includes a perpetual right to modify the software and thereby make
derivative works and/or other improvements to the software for the benefit of
Licensee's business. Licensor acknowledges that Licensee shall exclusively own
all rights in any such improvements, including all copyrights therein. The
license does not include any right of the Licensee to sell or sublicense the
software. The Parties further agree that the license to make modifications and
to use the corresponding source code may be revoked if Licensor, or its
successor, reduces its ownership in Licensee to less than fifty percent (50%).
Any such revocation must be specific, in writing, and provided to Licensee with
ninety (90) days advance notice. Licensee will either return all source code or
verify the source code will not be used and has been deleted.

All ownership of all intellectual property in the Software is retained by
Licensor. The licenses granted herein are subject to any and all third party
obligations. Third party obligations are obligations imposed on Licensor under
pre-existing licenses with parties other than Licensee.

2. SOURCE CODE

Licensor agrees to provide Licensee with the source code to the Software and all
corresponding documentation within ninety (90) days of the effective date of
this Agreement. Licensor further agrees to provide reasonable assistance to
Licensee regarding the implementation and use of the subject source code.

3. TERM

This Agreement shall be effective as of the date first above written and shall
extend in perpetuity.

4. COMPENSATION

In consideration for the license granted hereunder, Licensee agrees to pay to
Licensor five hundred thousand dollars ($500,000.00) payable to Licensor within
thirty (30) days of Licensee's acceptance of the subject source code. Licensee
further agrees to pay to Licensor all reasonable costs incurred by Licensor in
transferring the source code to Licensee within the period described above. The
reasonable costs billed to Licensee will be consistent with the accounting and
cost reimbursement formuli in the Corporate Services Agreement dated January 1,
1994 and the AEPT Technical Services Agreement dated October 1, 1993 between the
Parties as applicable to the various source codes covered hereby. Acceptance of
the source code shall occur when Licensee has received the source code and
determined it to be compilable. Licensee is responsible for third party software
needed to complete the compilation.

5. CONFIDENTIALITY

To the extent any Software is protected as a trade secret, Vastar agrees on
behalf of itself and its directors, officers and employees, (i) to keep such
trade secrets confidential, and (ii) not to

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disclose such trade secrets to others except as expressly otherwise authorized
in this Agreement and then to do so only after such others have first agreed in
writing to maintain the confidentiality of such trade secrets and not to
disclose same to any third party, provided, however, disclosures may be made to
third party agents of Vastar under appropriate secrecy and limited use terms and
conditions reasonably acceptable to ARCO, which approval will not be
unreasonably withheld, as is or may become necessary for the continuance of
Vastar's commercial operations, including, but not limited to, construction,
operations, maintenance, or repair of Vastar's wholly or partly owned
facilities.

The obligations of secrecy and limited use imposed on Vastar, its directors,
officers, employees, and authorized third party agents pursuant to this
Agreement shall not apply to written information or data which, as of the
Effective Date, (i) is or thereafter becomes through no fault of Vastar or its
directors, officers, employees or agents part of the public knowledge or (ii)
was subsequently received without binder of secrecy by Vastar or a director,
officer, employee or agent thereof from another source who owed no secrecy
obligation to ARCO or another.

Vastar shall not use the name of ARCO or any of its divisions or other
affiliates, nor make publicity releases regarding this Agreement or the Software
without obtaining the prior written consent of ARCO, which consent will not be
unreasonably withheld.

Vastar shall have its directors, officers, employees, and agents of any tier,
e.g., contractors or subcontractors, legally bound to the provisions of this
Section.

The terms and conditions of this Section shall survive any termination of this
Agreement.

6. WARRANTIES

Licensor represents and warrants that it has no actual knowledge that the
Software infringes any valid rights of any third party.

Except for the above warranty, the Software is furnished to Licensee on an "as
is" basis.  Licensor makes no other express warranties and disclaims all implied
warranties as to any matter whatsoever, including, without limitation, the
condition of the Software, its merchantability, or its fitness for any
particular purpose, or the correctness of output produced by the Software, or
the delivery, installation, furnishing, maintaining, or supporting of the
product by Licensor.  In no event will Licensor be liable for any damages,
including, without limitation, special, incidental, and consequential damages or
damages for lost data or profits, arising out of the use, or inability to use,
the Software.

7. INDEMNITY

Licensor agrees to defend, indemnify, and hold Licensee, and its officers,
directors, agents, and employees, harmless against all costs, expenses, and
losses (including reasonable attorney fees

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and costs) incurred through claims of third parties against Licensee based on a
breach by Licensor of any representation and warranty made in this Agreement.

Licensee shall use and/or otherwise rely upon the Software and shall allow its
authorized agents to use, and/or rely upon same in its sole discretion and at
its sole risk and expense, and Licensee shall indemnify, defend, and hold
Licensor harmless from any and all losses, claims, damages, judgments, costs,
expenses, and liabilities for such use, and/or reliance.

8. EXPORT COMPLIANCE

Licensee shall comply with all governmental laws, rules, and regulations in
respect of the export from the United States of any Software or related
technical information or data.

9. NOTICES

Any notice required to be given pursuant to this Agreement shall be in writing
and mailed by certified or registered mail, return receipt requested, or
delivered by a national overnight express service. Licensor's and Licensee's
addresses for notice purposes will be as follows:

To Licensor:  Atlantic Richfield Company
              2300 West Plano Parkway
              Plano, Texas 75075
              Attention: __________________

To Licensee:  Vastar Resources, Inc.
              15375 Memorial Drive
              Houston, Texas 77079
              Attention: Jo Preston

Either Party may change the address to which notice or payment is to be sent by
written notice to the other Party pursuant to the provisions of this paragraph.

10. JURISDICTION AND DISPUTES

This Agreement shall be governed by the laws of the state of Texas. All disputes
hereunder shall be resolved in the applicable state or federal courts of Texas.
The Parties consent to the exclusive jurisdiction of such courts, agree to
accept service of process by mail, and waive any jurisdictional or venue
defenses otherwise available.

11. AGREEMENT BINDING ON SUCCESSORS

This Agreement shall be binding on and shall inure to the benefit of the Parties
hereto, and their successors.

12. SEVERABILITY

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If any provision hereof is held invalid or unenforceable by a court of competent
jurisdiction, such invalidity shall not affect the validity or operation of any
other provision and such invalid provision shall be deemed to be severed from
the Agreement.

13. ASSIGNABILITY

The license granted hereunder is personal to Licensee and may not be assigned by
any act of Licensee unless in connection with a transfer of substantially all
the assets of Licensee to an assignee or a successor, or with the written
consent of Licensor.

14. INTEGRATION

This Agreement constitutes the entire understanding of the Parties, and revokes
and supersedes all prior agreements between the Parties pertinent to the matters
covered hereby and is intended as a final expression of their Agreement. This
Agreement shall not be modified or amended except in writing signed by the
Parties hereto and specifically referring to this Agreement. This Agreement
shall control over any other precedent document that may be in conflict
herewith.

IN WITNESS WHEREOF, the Parties hereto, intending to be legally bound hereby,
have each executed this Agreement effective as of the date first above written.

ATLANTIC RICHFIELD COMPANY           VASTAR RESOURCES, INC.

By: /s/ Stephen G. Suellentrop       By: /s/ Joseph P. McCoy
   -----------------------------        -----------------------------------

Title: Vice President                Title: Vice President and Controller
      --------------------------            -------------------------------

Date: 10/28/99                       Date: 10/26/99
     ---------------------------          ---------------------------------

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                       Exhibit A - Nontechnical Software

                          [DESCRIPTION APPEARS HERE]

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                         Exhibit B - Technical Software

                          [DESCRIPTION APPEARS HERE]

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                                                                   EXHIBIT 10.41

                             THROUGHPUT AGREEMENT
                             --------------------

  THIS THROUGHPUT AGREEMENT (the "Agreement") dated October 29, 1999 between
ARCO Pipe Line Company, a Delaware corporation ("Carrier"), and Vastar
Resources, Inc., a Delaware corporation ("Shipper"). Carrier and Shipper may
hereinafter be singularly referred to as "Party" and collectively referred to as
"Parties".

                                 WITNESSETH  THAT:

  In consideration of the mutual covenants herein contained and other good and
valuable consideration, receipt of which is hereby expressly acknowledge, the
Parties agree as follows:

  1.  TERM.  This Agreement shall become effective November 1, 1999 (the
      ----
"Effective Date") and shall continue for an initial term of five (5) consecutive
years thereafter (the "Term"). Each calendar year during the Term shall be
hereinafter referred to as an "Annual Period".

  2.  THROUGHPUT OBLIGATION.  The transportation performed by Carrier for
      ---------------------
Shipper hereunder shall be at the rates set forth herein and shall otherwise be
subject to the rules and regulations in Carrier's applicable tariffs in effect
during the Term of this Agreement (which tariffs are incorporated herein by
reference for all purposes).  If there is a conflict between the terms of this
Agreement and the terms of Carrier's published tariffs, the terms of this
Agreement shall be deemed controlling.

During the Term commencing November 1, 1999, Shipper shall tender and deliver to
Carrier one hundred percent (100%) of Shipper's equity Crude plus any third
party Crude controlled by the Shipper. The amount of Crude tendered by Shipper
to Carrier for transportation during each Annual Term shall hereinafter be
referred to as the "Throughput Obligation". Carrier agrees to transport the
volumes of Crude represented by the Throughput Obligation from Vastar Resources,
Inc.'s South Pass Platforms to Equilon Pipeline Company's Facilities, Main Pass
Block 69, Plaquemines Parish, Louisiana (the "Qualifying Movement"). Carrier
shall charge Shipper Forty-two Cents ($0.42) for each barrel of Crude
transported hereunder during the period from the Effective Date through and
including December 31, 1999. Carrier shall charge Shipper Thirty-four Cents
($0.34) for each barrel of Crude transported hereunder during the period
commencing January 1, 2000 and continuing thereafter for the remainder of the
Term.
  The Parties acknowledge and agree that the third party Crude potentially
controlled by the Shipper, comprised of Apache and Ocean Energy production in
the South Pass area, is an important component of this Agreement as is Shipper's
SP 60 area production.  Shipper covenants and agrees to use its reasonable
efforts to maintain and preserve its relationship and business arrangements with
Apache and Ocean Energy and companies marketing their production in order that
Apache/Ocean's Crude production from the South Pass area remain on Carrier's
pipeline

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destined to Main Pass Block 69.

  3.  DEFICIENCY PAYMENTS. Subject to Section 4 hereof, if, for any reason,
      -------------------
Shipper fails to fully perform its Throughput Obligation (as such Throughput
Obligations may be reduced in accordance with Section 2 above), Shipper shall
pay Carrier a Deficiency Payment (in cash) in an amount equal to the applicable
rate multiplied times the difference between: (a) the Throughput Obligation (as
applicable); and (b) the volume of Crude actually transported for Shipper on the
Qualifying Movement during such the Annual Term when the deficiency occurred.
This deficiency payment, if any, shall be made to Carrier not later than thirty
(30) days following Shipper's receipt of Carrier's invoice.

  Shipper shall also pay interest at the lower of: (i) the maximum lawful
interest rate; or (ii) the rate equivalent to One Hundred Ten Percent (110%) of
the prime rate (as announced from time to time by Citibank N.A. of New York, New
York on 90-day loans to substantial and responsible commercial borrowers) on all
amounts due and payable by Shipper hereunder which are not paid when due, such
interest calculated from the due date of such payment until payment thereof.

  4.  INTERRUPTION OF SERVICE.  Shipper shall be excused from performance of any
      -----------------------
Throughput Obligation to the extent caused by failure of pipeline facilities to
operate or the non-availability of space in pipeline facilities; provided
however, at Carrier's option, the Term shall be extended for a like period.

  5.  FORCE MAJEURE.  Neither Party shall be liable for discoloration,
      --------------
contamination, damage to or destruction of the Crude or property, and neither
Party shall be liable for any delay or nonperformance of its obligations under
this Agreement when any of the foregoing is caused in whole or in part by any
act of God or the public enemy or by labor troubles, strikes, lockouts, non-
availability of labor, riots, fires, storms, lightning, floods, hurricanes,
washouts, tornadoes, explosions, breakdown or failure of or accident to storage
tanks, docks, pipelines, machinery or equipment, transportation embargoes or
congestions, governmental embargoes or interventions, failure or delay of
manufacturers or person from whom the Party is obtaining Crude, machinery,
equipment, materials or supplies to deliver the same or from any law,
proclamation, regulation (including environmental protection regulations) or
order of any government, governmental agency or court having or claiming to have
jurisdiction over any part of facilities of either Party, or affiliates of
either Party,  cancellation or withdrawal of permits by government, governmental
agencies or any other cause beyond the Party's reasonable control, whether such
other causes be of the class herein specifically provided for or not and whether
the cause is or is not existing on the date of this Agreement; provided,
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however, at the  option of the Party not claiming force majeure, the term of
-------
this Agreement may be extended for a like period of time.

  6.  LIABILITY AND DAMAGES.  (a)  EXCEPT AS EXPRESSLY PROVIDED HEREIN, THERE
      ----------------------
ARE NO GUARANTEES OR WARRANTIES OR REPRESENTATIONS OF THE PARTIES OF ANY KIND,
EXPRESS OR IMPLIED,

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INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR
A PARTICULAR PURPOSE, WHETHER ARISING BY OPERATION OF LAW OR OTHERWISE.

  (b) Neither Party shall be liable to the other Party for loss or damage
related to or arising from special or consequential damages, no matter how or by
whom such loss or damage shall have occurred or been caused.

  7.  RATE. The rate for the Qualifying Movement shall be Forty-two Cents
      ----
($0.42) per barrel for the period from November 1, 1999 until December 31, 1999.
The rate for the Qualifying Movement shall be Thirty-four Cents ($0.34) per
barrel for the period January 1, 2000 until October 31, 2004. Shipper
acknowledges and agrees that such rates are just and reasonable.  If these rates
are ever determined by a judicial or regulatory authority to be inconsistent
with a lawful rate, the tariff rates shall be changed to the highest lawful rate
such judicial or regulatory authority shall permit; however, Shipper shall in no
event pay any higher than Forty-two Cents ($0.42) per barrel for Qualifying
Movements of the Throughput Obligation for the period November 1, 1999 through
December 31, 1999, nor shall Shipper in any event pay any higher than Thirty-
four Cents ($0.34) per barrel for Qualifying Movements of the Throughput
Obligation for the period January 1, 2000 through October 31, 2004.
   Should the volumes tendered to Carrier for transportation exceed the capacity
of the pipeline facilities, Carrier will prorate such volumes.

  8   COMPLIANCE.  Carrier shall comply, at its own cost and expense, with all
      ----------
applicable laws, rules and regulations of any federal, state or local
governmental agencies having jurisdiction over the pipeline facilities.

  9.  RIGHT OF FIRST REFUSAL.  If, during the Term, Carrier decides to sell to
      ----------------------
an unrelated third party all or any portion of the pipeline system on which the
Qualifying Movement is made, Carrier shall notify Shipper of the terms of the
offer for such purchase (including a copy of the proposed Sales Agreement, if
available), and Shipper shall have the right of first refusal to purchase the
pipeline system on the same terms as such offer, provided Shipper notifies
Carrier of its intent to do so within thirty (30) days after Carrier first
notifies Shipper of such offer.

  10. ENTIRE AGREEMENT.  This Agreement constitutes the entire agreement
      ----------------
between Carrier and Shipper and supersedes any prior written or oral agreements
or contemporaneous communications with respect to this subject matter, including
the Throughput Agreement dated April 4, 1994. The terms of this Amendment may
only be amended by a separate instrument executed by the Parties hereto.

  11.  NOTICES.  Notices and other communications provided for herein shall be
       -------
in  writing (which shall include notice by telex or facsimile machine with
answer back capability) and shall be delivered or mailed (or if by telex,
graphic scanning or other facsimile communications equipment of the sending
Party hereto, delivered by such equipment), addressed as follows:

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                    If to Carrier:

                    ARCO Pipe Line Company
                    15600 John F. Kennedy Boulevard, Suite 300
                    Houston, Texas 77032
                    Fax No.:  (281) 986-5486
                    Attention:  Ted Vacek, Business Development Consultant

               If to Shipper:

                    Vastar Resources, Inc.
                    15375 Memorial Drive
                    Houston, Texas 77079
                    Fax No.:  (713) 584-6515
                    Attention:  D. L. Stover, Area Manager, Offshore Gulf of
                                 Mexico

or to such other address as a Party may from time to time designate in writing
in accordance with this section. All notices and other communications given to
any Party hereto in accordance with the provisions of this Agreement shall be
deemed to have been given on the date of receipt.

     12.  GOVERNING LAWS.  THE INTERPRETATION, CONSTRUCTION AND PERFORMANCE OF
          --------------
THIS AGREEMENT AND THE RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE
GOVERNED BY THE LAW OF THE STATE OF TEXAS WITHOUT REGARD TO THE APPLICATION OF
CONFLICT OF LAWS PRINCIPLES.

     13.  CHANGE OF CONTROL.  In the event of the acquisition of the majority of
          -----------------
the issued and outstanding shares of either Party by a third party, the Parties
acknowledge and agree that the terms and conditions of this Agreement shall
remain in full force and effect and shall be fully binding upon the respective
successor(s)-in-interest of the Party (-ies).

     14.  ASSIGNMENT.
          -----------

     A.   Carrier may, without the consent of Shipper, assign all or a part of
its rights and/or obligations under this Agreement: (i) as collateral security
for a loan or loans for funds, or (ii) to a parent, subsidiary or related entity
of Carrier but the performance obligations under this Agreement of Carrier to
Shipper shall remain the responsibility of Carrier; otherwise, this Agreement
may not be assigned by Carrier without the prior written consent of Shipper,
which consent shall not be unreasonably withheld by Shipper.

     B.  Shipper may, without the consent of Carrier, assign all or a part of
its rights and obligations under this Agreement to a parent, subsidiary or
related entity of Shipper; otherwise, Shipper may assign its right under this
Agreement to a third party only with the prior written consent of Carrier, which
consent shall not be unreasonably withheld by Carrier.

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     C.  Subject to the foregoing, this Agreement shall inure to the benefit of
and be binding upon its successors and permitted assigns of the Parties hereto.
In the event of any assignment by either Party hereto (whether with or without
the consent of the non-assigning Party) the assigning Party shall remain
permanently liable to the other Party for all obligations now contained herein
regardless of whether such obligations were part of or covered by the
assignment.

     15.  SECTION AND PARAGRAPH HEADINGS.  The section and paragraph headings of
          ------------------------------
this Agreement are inserted for convenience only and are in no way to be
construed as part of this Agreement or as a limitation or enlargement of the
scope or meaning of the particular sections or paragraphs to which they refer
and shall not affect the interpretation of any provisions of this Agreement.

     16.  SEVERABILITY.  If any provisions of this Agreement shall be invalid or
          ------------
unenforceable to any extent, the remainder of this Agreement shall not be
affected thereby and shall be enforced to the greatest extent permitted by the
law.

     17.  WAIVER.  The waiver by or the failure of either Party to take action
          ------
with respect to any breach of any term, covenant or condition of this Agreement
shall not be deemed to constitute a waiver of such term, covenant or condition
on any subsequent breach of the term, covenant or condition.  The subsequent
acceptance of payments by Carrier under this Agreement shall not be deemed a
waiver of any preceding breach of any term, covenant or condition of this
Agreement other than the failure by Shipper  to pay the particular payment.

     18.  DUPLICATE ORIGINALS.  This Agreement is executed in duplicate
          -------------------
originals, with one original to be retained by each Party, but which together
shall constitute a single Agreement

     19.  ARBITRATION.  Any controversy, dispute, or claim of whatever nature
          ------------
rising out of, in connection with, or in relation to the interpretation,
performance or breach of this Agreement, including any claim based on contract,
tort, or statute, shall be settled, at the request of either Party, by final and
binding arbitration conducted at a location determined by the arbitrator(s) in
Houston, Harris County, Texas, administered by and in accordance with the
Commercial Arbitration Rules of the American Arbitration Association, and
judgment upon any award rendered by the arbitrator(s) may be entered by any
state or federal court having jurisdiction.

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          IN WITNESS WHEREOF, the Parties hereto have executed this Agreement as
of the date first above written.
                                                             -------------------
                                                             Approved as to Form
                                                             -------------------
                                                                      JAF
                                                             -------------------
                                                               Legal Department
                                                             -------------------

Attest:                                  ARCO Pipe Line Company

/s/ Ted Vacek    13/OCT/99               By /s/ Larry Shakley
--------------------------------------     --------------------------------
Name: Ted Vacek                          Name: Larry Shakley
Title: Business Development Consultant   Title: PRESIDENT

                                         - Carrier

Attest:                                  Vastar Resources, Inc.

/s/ Patrick L. McKern                    By /s/ Clay Bretches
--------------------------------------     ----------------------------------
Name: PATRICK L. MCKERN                  Name:  Clay Bretches
Title: DIR OFFSHORE CRUDE MARKETING      Title: Crude Oil Marketing Manager

                                         - Shipper

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