APACHE CORP
8-K, 1997-10-23
CRUDE PETROLEUM & NATURAL GAS
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<PAGE>   1
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549


                                   FORM  8-K


                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(D) OF THE

                        SECURITIES EXCHANGE ACT OF 1934




       Date of Report (Date of earliest event reported):  October 8, 1997




                               APACHE CORPORATION
               (Exact name of registrant as specified in Charter)


<TABLE>
     <S>                                           <C>                             <C>
               DELAWARE                               1-4300                             41-0747868
     (State or Other Jurisdiction                  (Commission                        (I.R.S. Employer
          of Incorporation)                        File Number)                    Identification Number)
</TABLE>


                            2000 POST OAK BOULEVARD
                                   SUITE 100
                           HOUSTON, TEXAS  77056-4400
                    (Address of Principal Executive Offices)

      Registrant's telephone number, including area code:  (713) 296-6000

================================================================================
<PAGE>   2

ITEM 2.          ACQUISITION OR DISPOSITION OF ASSETS

         Apache Corporation ("Apache"), either directly or through its
wholly-owned subsidiary, Apache Energy Limited ("AEL"), has entered into three
share sale agreements (the "Agreements") with subsidiaries of Mobil Exploration
& Producing Australia Pty Ltd ("MEPA") for the purchase of all of the capital
stock of Ampolex (A.O.E.) Pty Limited, Ampolex (Western Australia) Inc. and
Ampolex Varanus Pty Limited (together, the "Ampolex Companies") for a total of
approximately $310 million in cash, subject to certain adjustments.  Each of
the Agreements is dated October 8, 1997, effective as of July 1, 1997.  The
Agreements are listed under Item 7 as Exhibits 2.1, 2.2 and 2.3, respectively,
and are incorporated herein by reference.  Apache issued a press release, dated
October 8, 1997, which is listed under Item 7 as Exhibit 99.1 and incorporated
herein by reference.

         The consummation of the transactions represented by the Agreements,
which are subject to certain conditions including U.S. and Australian
government approvals, will increase (a) Apache's current 22.5-percent interest
to 47.5 percent in the Harriet area, which includes the Varanus Island
pipeline, processing and production complex and eight existing oil and gas
fields, and (b) Apache's current 20-percent interest to 55 percent in the East
Spar gas and condensate field, which produces through the Varanus Island
facilities.  The assets owned by the three companies being acquired by Apache
are used in producing, gathering and processing oil and natural gas, and Apache
intends to continue the use of such assets for the same purposes.

         Funds for the transaction will be obtained from one or more of
Apache's existing global credit facility or commercial paper program, and/or a
new bridge loan to AEL or a debt offering by AEL guaranteed by Apache.

         Other than the relationships mentioned above or provided for or
contemplated by the Agreements, there are no other material relationships among
MEPA, the Ampolex Companies and Apache or AEL or any of Apache's or AEL's
affiliates, officers or directors, or any associate of any officer of Apache or
AEL.



                                       1
<PAGE>   3

ITEM 7.  FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS


(c)      EXHIBITS.


<TABLE>
<CAPTION>
EXHIBIT NO.               DESCRIPTION
- -----------               -----------
<S>                       <C>
 2.1*                     Share Sale Agreement, Ampolex (A.O.E.) Pty Limited, between Ampolex Limited, as seller, and
                          Apache Energy Limited, as buyer, dated October 8, 1997.

 2.2*                     Share Sale Agreement, Ampolex (Western Australia) Inc., between Ampolex (PNG Holdings) Inc., as
                          seller, and Apache Corporation, as buyer, dated October 8, 1997.

 2.3*                     Share Sale Agreement, Ampolex Varanus Pty Limited, between Ampolex Limited, as seller, and
                          Apache Energy Limited, as buyer, dated October 8, 1997.

99.1*                     Press Release, dated October 8, 1997, "Apache to Acquire Australian Properties and Facilities
                          from Mobil for $310 Million".
</TABLE>

- --------------
*filed herewith



                                       2
<PAGE>   4

                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                             APACHE CORPORATION


Date:  October 23, 1997                      /s/ Z. S. Kobiashvili
                                             ----------------------------------
                                             Z. S. Kobiashvili
                                             Vice President and General Counsel


                                       3
<PAGE>   5
                                EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT NO.               DESCRIPTION
- -----------               -----------
<S>                       <C>
 2.1*                     Share Sale Agreement, Ampolex (A.O.E.) Pty Limited, between Ampolex Limited, as seller, and
                          Apache Energy Limited, as buyer, dated October 8, 1997.

 2.2*                     Share Sale Agreement, Ampolex (Western Australia) Inc., between Ampolex (PNG Holdings) Inc., as
                          seller, and Apache Corporation, as buyer, dated October 8, 1997.

 2.3*                     Share Sale Agreement, Ampolex Varanus Pty Limited, between Ampolex Limited, as seller, and
                          Apache Energy Limited, as buyer, dated October 8, 1997.

99.1*                     Press Release, dated October 8, 1997, "Apache to Acquire Australian Properties and Facilities
                          from Mobil for $310 Million".
</TABLE>

- --------------
*filed herewith




<PAGE>   1

                                  EXHIBIT 2.1


    SHARE SALE AGREEMENT
AMPOLEX (A.O.E.) PTY LIMITED

      AMPOLEX LIMITED
      ACN 000 113 217

            and

   APACHE ENERGY LIMITED
      ACN 009 301 964
<PAGE>   2

THIS AGREEMENT is made     8th     October     1997

BETWEEN

AMPOLEX LIMITED ACN 000 113 217 of Level 29, 250 St Georges Terrace, Perth,
Western Australia (SELLER)

AND

APACHE ENERGY LIMITED ACN 009 301 964 of Level 3, 256 St Georges Terrace,
Perth, Western Australia (BUYER)

RECITALS:

A.       The Company is engaged in the business of producing hydrocarbons in
         Western Australia.

B.       The Seller is the legal and beneficial owner of the Shares being the
         whole of the issued share capital of the Company.

C.       The Seller has agreed to sell the Shares to the Buyer, and the Buyer
         has agreed to purchase the Shares from the Seller on the terms and
         conditions set out in this Agreement.

The Parties AGREE:

1.       DEFINITIONS

1.1      Unless otherwise required by the context or subject matter:

         ADJUSTMENT AMOUNT is defined in clause 6.4;

         AGREED RATE means the THIRTY (30) day Bank Bill Swap Reference Rate
         (source Bloomberg) published in the Australian Financial Review in
         respect of the first Business Day of each month or part month for
         which interest is to be calculated;

         AGREEMENT means this agreement as amended, supplemented or varied from
         time to time;

         ASSETS means the interest of the Company as listed in Schedule One and
         in Schedule Five in and under:

         (a)     the Titles and all other rights, titles and interests in the
                 Titles subject to the terms and conditions of their grant;





                                       1.
<PAGE>   3
         (b)     the Joint Venture Contracts, including any joint venture
                 property held under those contracts;

         (c)     the Information; and

         (d)     all other miscellaneous assets, rights, property and interests
                 associated or employed in relation to the Assets, including
                 the right to produce Petroleum in accordance with that
                 interest;

         BALANCE SHEET means the balance sheet of the Company as audited by
         Ernst & Young annexed as Schedule 7 prepared on the basis set out in
         the notes to the Balance Sheet and on the basis that the Prior
         Properties and Prior Subsidiaries are no longer owned by the Company;

         BANK ACCOUNT means any bank account in the name of the Company;

         BUSINESS DAY means a day (during the hours of 9.00am to 5.00pm Perth
         time) on which trading banks are open for business in Perth, Western
         Australia;

         BUYER ACCOUNT means an account of amounts owed by the Buyer to the
         Seller determined under Schedule 4;

         BUYER'S SOLICITORS means Arthur Robinson & Hedderwicks of 530 Collins
         Street, Melbourne, Victoria;
        
         COMPANY means Ampolex (A.O.E.) Pty Limited (ACN 008 674 413);

         COMPLETION means completion of the sale and purchase of the Shares
         under Clause 9;

         COMPLETION DATE means the later of:

         (a)     14 November 1997; or

         (b)     the day falling FIVE (5) Business Days after the Conditions
                 are satisfied; or

         such other date as the Parties may agree in writing;

         CONDITION means any conditions specified in clauses 3 and 4 inclusive
         and CONDITIONS means all of them;

         DOLLARS or $ means Australian dollars unless otherwise stated;

         EFFECTIVE DATE means 00.01am, 1 July 1997 Perth time;

         ENCUMBRANCE means a mortgage, charge, whether fixed or floating, bill
         of sale, pledge, lien, charging order, stop order, writ of execution,
         title retention or conditional sales agreement, hire or hire purchase
         agreement, lease, licence to use or occupy, option, restriction as to
         transfer, use or possession,





                                       2.
<PAGE>   4
         easement, caveat and the claim stated in that caveat, equity interest
         and any other security interest or other third party right or
         interest;

         GOVERNMENTAL AGENCY means any government or governmental,
         semi-governmental, administrative, fiscal or judicial body,
         department, commission, authority, tribunal, agency or entity;

         INDEPENDENT ACCOUNTANT means the chartered accountant referred to in
         Schedule Six;

         INFORMATION means geological, geophysical or technical information
         within the custody or control of the Company being material
         information that relates to the presence, absence or extent of
         hydrocarbon deposits in the area of the Assets and has been obtained
         from the exploration and prospecting for or production of hydrocarbons
         within Assets including, without limitation, the books, records,
         seismic and interpretive data, notes, drawings, maps and other
         information (in various media) related to the Assets;

         INTER-COMPANY LOANS means any and all amounts outstanding on any
         inter-company loan account owed by the Company to the Seller or any
         Related Body Corporate of the Seller at the Effective Date which is
         irrevocably agreed to be an amount of ONE HUNDRED AND SIXTEEN MILLION
         SEVEN HUNDRED AND SEVEN THOUSAND FIVE HUNDRED AND TWENTY DOLLARS AND
         EIGHTY ONE CENTS ($116,707,520.81), plus interest at the Agreed Rate
         calculated daily and compounded monthly during the Interim Period;

         INTERIM PERIOD means the period between the Effective Date and the
         Completion Date;

         JOINT VENTURE means all or any of, as the context requires, the
         relationships established under the Joint Venture Contracts;

         JOINT VENTURE CONTRACTS means the contracts listed as such in Schedule
         Five;

         OPERATOR means Apache Oil Australia Pty Ltd;

         OTHER AGREEMENTS means:

         (a)     an agreement entered into on the date of this Agreement
                 between Ampolex (PNG Holdings) Inc and the Buyer or a Related
                 Body Corporate of the Buyer for the sale of the issued shares
                 in Ampolex (Western Australia) Inc.; and

         (b)     an agreement entered into on the date of this Agreement
                 between Ampolex Limited and the Buyer or a Related Body
                 Corporate of the Buyer for the sale of the issued shares in
                 Ampolex Varanus Pty Limited;

         PARTY means the Seller or the Buyer according to the context and
         PARTIES means both the Seller and the Buyer;





                                       3.
<PAGE>   5
         PETROLEUM has the meaning given in the Petroleum (Submerged Lands) Act
         (WA) 1982;

         PETROLEUM LEGISLATION means the Petroleum Act (WA) 1967, the Petroleum
         (Submerged Lands) Act (Cth) 1967, the Petroleum (Submerged Lands) Act
         (WA) 1982, the Petroleum Pipelines Act (WA) 1969 any other Act of
         Parliament with which each Act is incorporated, as well as all
         regulations, administrative directions and determinations made under
         any of those Acts;

         PRIOR PROPERTIES means the interest of the Company in:

         (a)     Exploration Permit for Petroleum No. WA-214-P and the related
                 joint operating agreement to be assigned to Ampolex AE Pty
                 Limited effective 31 July 1997;

         (b)     the Perth Basin including production licences Nos. L1 and L2
                 and pipeline licences Nos. PL1, PL2, PL3, PL5 and PL23 sold to
                 CMS Gas Transmission of Australia; and

         (c)     the Tunisian permits El Jem and Anaguid assigned to Ampolex
                 (Tunisia) Pty Ltd.

         PRIOR SUBSIDIARIES means Ampolex Indonesia Pty Ltd (ACN 073 659 211),
         Ampolex (USA) Inc. and Ampolex (New Zealand) Ltd and any wholly owned
         subsidiary of these corporations;

         PURCHASE PRICE means the cash consideration of ONE HUNDRED AND SIXTY
         EIGHT MILLION SIX HUNDRED AND TWENTY FIVE THOUSAND TWO HUNDRED AND
         TWENTY FOUR DOLLARS AND SEVENTY SEVEN CENTS ($168,625,224.77) (which
         amount includes working capital as at the Effective Date) as adjusted
         in accordance with Clause 6 and Schedule Four, plus interest at the
         Agreed Rate calculated daily and compounded monthly during the Interim
         Period;

         RELATED BODY CORPORATE has the meaning given to that expression in the
         Corporations Law;

         SALE means the sale and purchase of the Shares in accordance with the
         terms of this Agreement;

         SALES CONTRACTS means the contracts listed as such in Schedule 5;

         SCHEDULE means a schedule to this Agreement;

         SELLER ACCOUNT means an account of amounts owed by the Seller to the
         Buyer determined under Schedule 4;

         SELLER'S SOLICITORS means Freehill, Hollingdale & Page of 140 St
         Georges Terrace, Perth, Western Australia;





                                       4.
<PAGE>   6
         SHARES means the 11,222,789 shares in the Company having a par value
         of $0.50 being all the issued shares in the capital of the Company;

         SPECIFIED ENCUMBRANCES means the encumbrances specified in Schedule
         One;

         TAX means all federal, state, local or foreign taxes and charges
         including but not limited to income, gross receipts, windfall profits,
         goods and services, value added, transfer, property, sales,
         production, use, license, excise, franchise, withholding or similar
         taxes, together with any interest, additions or penalties and any
         interest in respect of such additions or penalties;

         TITLES means the petroleum titles and licences specified in Schedule
         One; and

         WARRANTIES mean the warranties and representations set out in:-

         (a)     Schedule Two in the case of the Seller; and

         (b)     Schedule Three in the case of the Buyer.

2.       SALE SUBJECT TO CONDITIONS

         The Sale is conditional on satisfaction of each and every Condition.

3.       HART-SCOTT-RODINO CONDITION

         This Agreement is subject in all respects to and conditional upon
         compliance by the Parties with the Hart- Scott-Rodino Antitrust
         Improvements Act of 1976, and rules and regulations promulgated
         pursuant thereto in respect of the transactions contemplated by this
         Agreement and the Other Agreements.

4.       FIRB CONDITION

4.1      DEFINITION

         In this subclause:

         ACT means the Foreign Acquisitions and Takeovers Act (Cth) 1975; and

         TREASURER means the Treasurer of Australia.

4.2      SALE SUBJECT TO APPROVAL

         The Sale is conditional on the Treasurer either:

         (a)     advising the Buyer that the Treasurer has no objection to the
                 acquisition of the Shares by the Buyer and the transactions
                 contemplated by the Other Agreements either:

                 (i)      unconditionally; or





                                       5.
<PAGE>   7
                 (ii)     subject to conditions with which the Buyer (or its
                          Related Body Corporate, as the case may be) is
                          willing to comply; or

         (b)     ceasing to be empowered under the Act to make an order
                 prohibiting the acquisition of the Shares by the Buyer and the
                 transactions contemplated by the Other Agreements;

         whichever occurs first.

4.3      NOTICE TO BE GIVEN TO TREASURER

         The Buyer must:

         (a)     give notice to the Treasurer under section 25 of the Act in
                 the prescribed form; and

         (b)     comply with all directions on that form;

         within TEN (10) Business Days from the date of this Agreement.

4.4      PARTIES' OBLIGATIONS

         (a)     The Buyer must use all reasonable endeavours to obtain the
                 approval of the Treasurer to the Sale under the Act.

         (b)     The Parties must (and the Seller must ensure that the Company
                 will) do all things and provide all information and documents
                 required by the Treasurer or the Foreign Investment Review
                 Board in connection with the application for approval of the
                 Sale under the Act as soon as reasonably practicable after
                 being notified of the required things, information or
                 documents.

4.5      BENEFIT OF CONDITION

         This Condition:

         (a)     is for the benefit of the Seller and the Buyer; and

         (b)     may not be waived.

4.6      CONDITION NOT FULFILLED

         If approval of the Treasurer is denied, then:

         (a)     the Sale will terminate automatically without notice; and

         (b)     subject to the rights of either Party in respect of any
                 antecedent breach of the provisions of this Agreement:

                 (i)      neither the Seller nor the Buyer will have any claim
                          against the other; and





                                       6.
<PAGE>   8
                 (ii)     this Agreement, other than this subclause, will have
                          no further effect.

5.       SALE AND PURCHASE

         At Completion, the Seller agrees to sell and transfer to the Buyer,
         and the Buyer agrees to purchase from the Seller the Shares free from
         Encumbrances for the Purchase Price on the terms and conditions of
         this Agreement.

6.       CONSIDERATION

6.1      PURCHASE PRICE

         The Buyer shall pay the Seller the Purchase Price subject to any
         adjustments required by this Agreement.

6.2      BUYER ACCOUNT

         The Buyer must pay to the Seller in addition to the Purchase Price the
         amount charged to the Buyer Account plus interest at the Agreed Rate
         calculated daily and compounded monthly.

6.3      SELLER ACCOUNT

         The Seller must pay by way of a deduction to the Purchase Price the
         amount charged to the Seller Account plus interest at the Agreed Rate
         calculated daily and compounded monthly.

6.4      PAYMENT

         Other than in respect of the amounts agreed or determined under
         Schedule Four, the payments under this Clause shall be paid at
         Completion and the Buyer Account and the Seller Account may be offset
         so that only one payment is made as between the Buyer and the Seller
         (ADJUSTMENT AMOUNT).

6.5      INTER-COMPANY LOANS

         In addition to the amounts payable by the Buyer to the Seller under
         this clause, the Buyer must make sufficient funds available to the
         Company to enable the Company to discharge the Inter-company Loans at
         Completion.

6.6      POST COMPLETION/FINAL ADJUSTMENT

         Any matters not finally determined by and paid on the Completion Date
         will be resolved and payment made pursuant to the procedure described
         in Schedule Four.

6.7      FURTHER ADJUSTMENT

         If at any time during the period of THREE (3) years following the
         Completion Date the:





                                       7.
<PAGE>   9
         (a)     Buyer becomes:

                 (i)      entitled to or receives funds, revenues, refunds,
                          credits or payments; or

                 (ii)     liable to pay (and subject to this clause, does or
                          agrees to pay) costs, expenses and expenditure;

                 which are attributable to the Assets and relate to the period
                 before the Effective Date; or


         (b)     Seller becomes:

                 (i)      entitled to or receives funds, revenues, refunds,
                          credits or payments; or

                 (ii)     liable to pay (and subject to this clause, does or
                          agrees to pay) costs, expenses and expenditure;

                 which are attributable to the Assets and relate to the period
                 after the Effective Date;

         (in all cases, which amounts or liabilities were not otherwise
         specifically adjusted for in this Agreement), in an amount or amounts
         aggregating or exceeding not less than TEN THOUSAND DOLLARS
         ($10,000.00), then

         (c)     the Buyer shall account to the Seller within THIRTY (30) days
                 of such adjustments in respect of paragraphs 6.7(a)(i) and
                 6.7(b)(ii); and

         (d)     the Seller shall account to the Buyer within THIRTY (30) days
                 of such adjustments in respect of paragraphs 6.7(a)(ii) and
                 6.7(b)(i),

         for such funds, revenues, liabilities, costs, expenses, refunds,
         credits or payments and, where an amount relates partially to periods
         before and after the Effective Date, then the amount shall be
         equitably apportioned between the Seller and the Buyer. A Party shall
         be entitled to set off amounts payable by the other Party in making
         account to that other Party. A reference to the Buyer and the Seller
         in paragraphs (a) and (b) of this Clause includes a reference to the
         Company, where the Company receives an amount or incurs a liability to
         be adjusted under this Clause.

7.       ACCESS TO COMPANY RECORDS

         From the date of this Agreement, the Seller shall and shall cause the
         Company to allow reasonable access by the Buyer to all of the
         Company's books, accounts and documents in connection with the Company
         and the Shares, and information concerning the Company relevant to the
         Sale.





                                       8.
<PAGE>   10
8.       PERIOD BEFORE COMPLETION

8.1      CARRYING ON OF BUSINESS

         The Seller shall cause that between the date of execution of this
         Agreement and the Completion Date:

         (a)     the Company informs and consults with the Buyer on all
                 material matters relating to the conduct of the business of
                 the Company and will procure that such business is conducted
                 in a diligent and ordinary and usual manner. In particular,
                 but without prejudice to the generality of the foregoing, the
                 Seller will procure that the Company consults with the Buyer
                 before the Company:

                 (i)      approves any new or varied programme and budget of
                          operations;

                 (ii)     approves any drilling operations which are not at the
                          date of this Agreement approved or identified in an
                          approved programme and budget;

                 (iii)    approves any other matter likely to affect in any
                          material respect the nature or extent of expenditure
                          obligations of the Company;

                 (iv)     in any other respect, exercises any voting right
                          under any Joint Venture Contract;

         (b)     the Company does not acquire or dispose of any Asset, other
                 than acquisitions or disposals of Petroleum, stocks or
                 receivables in the ordinary course of business without the
                 prior written consent of the Buyer;

         (c)     the Company does not create any Encumbrances over any of the
                 Assets without the prior written consent of the Buyer;

         (d)     the Company pays when due all cash calls under the Joint
                 Venture Contracts;

         (e)     the Company does not vary the terms of sale of its share of
                 Petroleum derived from the Assets pursuant to the Sale
                 Contracts;

         (f)     without the prior written approval of the Buyer (which
                 approval shall not be unreasonably withheld), the Company will
                 not:-

                 (i)      give notice of or otherwise institute in any sole
                          risk or non-consent operation;

                 (ii)     farm-out the Assets;

                 (iii)    surrender or relinquish of any part of the Assets; or





                                       9.
<PAGE>   11
                 (iv)     execute any instrument amending, waiving or
                          cancelling any provision of the Joint Venture
                          Contracts;

         (g)     the Company provides to the Buyer copies of all material
                 notices issued by the Operator in respect of the Assets;

         (h)     the Company does not issue any shares, options or securities
                 which are convertible into shares in the Company;

         (i)     the Company does not engage any employees;

         (j)     the Company does not alter its memorandum or Articles of
                 Association without the prior written consent of the Buyer;

         (k)     the Company does not incur any liabilities, enter into any
                 contract or commitment or engage in any activity other than in
                 the ordinary course of business; and

         (l)     the business of the Company is conducted so as to comply in
                 all material respects with all applicable laws and regulations

         PROVIDED THAT the Seller will not be liable to the Buyer for any
         breach of an obligation imposed in this Clause 8.1 which arises from a
         course of action, to the extent that the Seller has consulted with the
         Deputy Managing Director of the Buyer prior to undertaking such course
         of action and the Buyer has not objected in writing as soon as
         practicable after such consultation.

8.2      ACCESS TO INFORMATION

         (a)     In addition to its obligations under Clause 8.1, the Seller
                 will procure that the Company will, subject to any
                 confidentiality restrictions contained in the Joint Venture
                 Contracts and this Agreement and subject to reasonable notice,
                 give the Buyer reasonable access to the Information and any
                 other matters relating to the Assets during normal working
                 hours and provide copies thereof, at the Buyer's cost.

         (b)     In exercising its rights under Clause 8.2(a), the Buyer will
                 not unreasonably interfere with the business or operations of
                 the Seller or the Company.

         (c)     If this Agreement is terminated for whatever reason, the Buyer
                 must promptly return all Information to the Seller.

8.3      INSURANCE

         During the Interim Period, the Seller will ensure that the Company
         maintains the insurances taken out in respect of the Assets as at the
         Effective Date. These insurances will be at the cost of the Buyer and
         adjusted for under Schedule 4.





                                      10.
<PAGE>   12
9.       COMPLETION

9.1      COMPLETION LOCATION

         Completion will take place at the Seller's Solicitors' office.

9.2      COMPLETION DATE

         The Parties must effect Completion on the Completion Date at a time
         agreed by the Buyer and the Seller.

9.3      SELLER'S OBLIGATIONS

         At Completion, the Seller must deliver to the Buyer:

         (a)     a duly executed but unstamped transfer of the Shares, together
                 with the relevant share certificates;

         (b)     (i)      the common seal and any duplicate or official seals;

                 (ii)     any Memorandum and Articles of Association of the
                          Company in the possession of the Seller;

                 (iii)    all minutes of meetings of directors and shareholders
                          of the Company;

                 (iv)     all registers of the Company;

                 (v)      copies of all income tax returns lodged by the
                          Company before the Completion Date and supporting tax
                          return work papers in possession of the Company;

                 (vi)     all books, ledgers, records and other documents and
                          data of the Company in either written or electronic
                          form; and

                 (vii)    a signed notice to each Purchaser under the Sale
                          Contracts nominating a new Bank Account into which
                          proceeds of sale of Petroleum can be made;

         (c)     a release and discharge in favour of the Company in respect of
                 the Inter-company Loans;

         (d)     a legal opinion by the Seller's Solicitors in a form
                 reasonably satisfactory to the Buyer and the Buyer's
                 Solicitors stating that this Agreement is, and will be,
                 enforceable against the Seller in all respects in accordance
                 with its terms;

         (e)     a certificate signed on behalf of the Seller by two authorised
                 officers (AUTHORISED OFFICERS) stating that all the
                 representations and warranties given by the Seller in this
                 Agreement are true and correct as at Completion and that the
                 Seller is not in breach of any of its obligations under this
                 Agreement;





                                      11.
<PAGE>   13
         (f)     copies of board resolutions certified as true and correct by
                 an Authorised Officer in which the directors of the Seller
                 authorise the execution of this Agreement and the performance
                 of the Seller of the transactions contemplated by this
                 Agreement;

         (g)     certificates of incumbency in respect of each Authorised
                 Officer confirming the authority of each of them to sign the
                 certificate referred to in Clause 9.3(e) on behalf of the
                 Seller; and

         (h)     the Adjustment Amount, if the Seller Account plus interest at
                 the Agreed Rate calculated daily and compounded monthly is
                 greater than the Buyer Account plus interest at the Agreed
                 Rate calculated daily and compounded monthly.

9.4      OTHER OBLIGATIONS OF SELLER ON COMPLETION

         As part of Completion, on payment of the Purchase Price and, subject
         to Clause 9.5(a), payment of the Adjustment Amount to the Seller and
         the Inter-company Loans to Company, the Seller shall cause the
         directors of the Company to hold a meeting with effect at Completion
         at which the directors, in accordance with the Company's articles of
         association:

         (a)     appoint the Buyer's nominees as additional directors of the
                 Company;

         (b)     appoint the Buyer's nominee as an additional secretary of the
                 Company;

         (c)     approve for registration, subject to payment of stamp duty,
                 the transfer of the Shares to the Buyer;

         (d)     (i)      authorise the signature of all authorities necessary
                          to revoke all existing authorities to bankers in
                          relation to the operation of the Bank Accounts; and

                 (ii)     appoint, in the manner the Buyer directs, the Buyer's
                          nominees as the persons authorised to operate the
                          Bank Accounts.

         (e)     table and accept resignations of:

                 (i)      the public officer;

                 (ii)     the secretary, other than the secretary nominated by
                          the Buyer; and

                 (iii)    the directors, other than the directors nominated by
                          the Buyer;

                 to take effect on and from the close of business of the
                 meeting; and





                                      12.
<PAGE>   14
         (f)     sign all forms required to be signed by the outgoing directors
                 and secretary under the Corporations Law.

9.5      THE BUYER'S OBLIGATIONS AT COMPLETION

         At Completion, the Buyer must:

         (a)     by means of confirmed electronic funds transfer to a bank
                 account in the name of the Seller as nominated by the Seller
                 to the Buyer for value at Completion in Australian dollars:

                 (i)      pay to the Seller the Purchase Price and, if the
                          Buyer Account plus interest at the Agreed Rate
                          calculated daily and compounded monthly is greater
                          than the Seller Account plus interest at the Agreed
                          Rate calculated daily and compounded monthly, the
                          Adjustment Amount; and

                 (ii)     procure that the Company pays to the Seller the
                          agreed sum in respect of the Inter-company Loans on
                          Completion;

         (b)     deliver to the Seller:

                 (i)      a legal opinion by the Buyer's Solicitors in a form
                          reasonably satisfactory to the Seller and the
                          Seller's Solicitors, stating that this Agreement is,
                          and will be, enforceable against the Buyer in all
                          respects in accordance with its terms;

                 (ii)     a certificate signed on behalf of the Buyer by two
                          authorised officers (AUTHORISED OFFICERS) stating
                          that all the representations and warranties given by
                          the Buyer in this Agreement are true and correct as
                          at Completion and that the Buyer is not in breach of
                          any of its obligations under this Agreement;

                 (iii)    copies of board resolutions certified as true and
                          correct by an Authorised Officer in which the
                          directors of the Buyer authorise the execution of
                          this Agreement and the performance of the Buyer of
                          the transactions contemplated by this Agreement; and

                 (iv)     certificates of incumbency in respect of each
                          Authorised Officer confirming the authority of each
                          of them to sign the certificate referred to in
                          paragraph (ii) on behalf of the Buyer.
9.6      COMPLIANCE

         Neither the Buyer nor the Seller will be obliged to proceed to
         Completion unless:

         (a)     there is no material breach of Clause 8 which remains
                 unremedied; and

         (b)     the other of them complies with all of its obligations under
                 this Clause 9.





                                      13.
<PAGE>   15
9.7      OTHER DOCUMENTS

         As soon as possible after Completion, the Seller will cause to be
         delivered at the Buyer's cost to the Buyer:

         (a)     all technical and other data, books, records, accounts,
                 contracts, maps, notes, drawings and other information
                 (regardless of form) constituting the Information in the
                 possession and the control of the Seller requested by the
                 Buyer; and

         (b)     all original Joint Venture Contracts and Sales Contracts (to
                 the extent that they are in the possession of or under the
                 control of the Seller) or otherwise copies thereof and any
                 other document that evidences the Company's title to Assets.

10.      POST COMPLETION

10.1     EXERCISE OF RIGHTS

         From Completion and until the Shares are registered in the name of the
         Buyer, the Seller agrees, in relation to the Shares, at the cost of
         the Buyer, to act in accordance with the directions of the persons
         appointed under Clause 9.4(a).

10.2     CHANGE OF NAME

         The Buyer shall cause the Company to change its name to a name not
         associated with the Seller or any Related Body Corporate of the Seller
         and register the proposed change of name with the appropriate
         regulatory authority for approval within TEN (10) Business Days of
         Completion.

10.3     INDEMNITY

         The Buyer indemnifies and holds harmless the Seller from any and all
         liability whatsoever arising out of the implementation of any
         direction given under Clause 10.1.

10.4     POST COMPLETION AUDIT OF OPERATOR'S ACCOUNTS

         (a)     The Buyer acknowledges that for a period of THREE (3) years
                 after the Completion Date the Seller retains its rights to
                 participate in the audits of the Operator's books to be
                 conducted under the terms of the Joint Venture Contracts
                 (subject to any confidentiality restrictions contained in the
                 Joint Venture Contracts and the Buyer agrees to use its
                 reasonable endeavours to enable the Seller to so participate)
                 in respect of the period prior to the Effective Date (and may
                 nominate a representative to attend as a representative of the
                 Buyer at its own cost) and will be entitled to and responsible
                 for any adjustment made to any account maintained under the
                 Joint Venture Contracts arising as a result of any such audit
                 in respect of the period prior to the Effective Date.





                                      14.
<PAGE>   16
         (b)     If as a consequence of such audit, adjustments are made to any
                 of the entries in the Working Capital Statement referred to in
                 Schedule Four, a further adjustment will be paid to the Party
                 entitled within THIRTY (30) Business Days of the results of
                 that audit, provided that no claim can be made under this
                 Clause unless the net balance due is greater than TEN THOUSAND
                 DOLLARS ($10,000).

10.5     PRESERVATION OF RECORDS

         (a)     The Buyer must, at its own expense, preserve and keep the
                 records held by it or the Company relating to the business of
                 the Company for a period of SIX (6) years from the Completion
                 Date and shall make such records and personnel available to
                 Seller as may be reasonably required by Seller in connection
                 with, among other things, any insurance claim, legal
                 proceedings, the tax affairs of the Seller or any governmental
                 investigation (including investigation and audits by any
                 taxing authority) relating to the business of the Company
                 prior to the Completion Date.

         (b)     The Buyer consents to the Seller retaining copies of all
                 corporate and Tax records relating to the Company or the
                 Assets provided that the Seller shall not use or disclose them
                 for any purpose other than as contemplated under Clause
                 10.5(a).

11.      TAX REQUIREMENTS

11.1     INFORMATION

         The Seller agrees to make available to the Buyer all information in
         its custody or control relating to the Company or relating to the
         Assets in respect of any period before the Completion Date which the
         Buyer needs to know to enable it to cause the Company to complete any
         Tax return or to make any claim for the undeducted allowable
         expenditure and the undeducted allowable capital expenditure.

11.2     REASONABLE ASSISTANCE

         The Seller agrees to give to the Buyer all reasonable assistance in
         connection with any tax audit of the Company after the Completion Date
         in respect of any period before the Completion Date, provided that the
         Seller's obligation under this clause terminates THREE (3) years after
         the Completion Date.

11.3     TAX RETURNS

         Any income tax return and supporting schedules submitted in relation
         to the Company will be consistent with the rollover notices given by
         the Company in connection with the divestment of the Prior
         Subsidiaries and Prior Properties and copies will be provided to the
         Seller.

11.4     BUYER OBLIGATIONS

         The Buyer will not:





                                      15.
<PAGE>   17
         (a)     in relation to any Tax, amend any declaration, election or
                 selection, the giving of a notice or the exercise of an option
                 by the Company in respect of the period ending before the
                 Completion Date without the Seller's prior written consent,
                 which consent shall not be unreasonably withheld;

         (b)     fail to submit any income tax return in relation to the
                 Company for any period which includes the period commencing on
                 the day following the Completion Date and ending at the end of
                 the tax year in which the Completion Date occurs; or

         (c)     amend any income tax return of the Company for any tax year
                 ending at or prior to the end of the tax year in which the
                 Completion Date occurs without the Seller's prior written
                 consent, which consent shall not be unreasonably withheld.

         In this clause, "tax year" means a year ending on 30 June or, where
         the company has a substituted accounting period (within Section 18 of
         the Income Tax Assessment Act 1936, as amended) ending on some date
         other than 30 June, that date.

11.5     SELLER OBLIGATIONS

         The Seller will not submit any income tax return in relation to the
         Company for any period ending before the Completion Date without the
         Buyer's prior written consent, which consent must not be unreasonably
         withheld.

11.6     U.S. INCOME TAX STATUS

         The Buyer acknowledges that the Company has or will have status as a
         branch of the Seller for United States income tax purposes and agrees
         that the Seller may take all such actions as it deems appropriate for
         the Company to qualify as a branch of the Seller for United States
         income tax purposes in respect of the period prior to and ending on
         the Completion Date.

12.      WARRANTIES

12.1     SELLER

         The Seller makes the Warranties in favour of the Buyer as at the
         Effective Date and as at the Completion Date.  The Warranties are made
         subject to the qualifications made in this Agreement and in the
         Schedules and subject to any disclosures made by the Seller in writing
         on or prior to the date of this Agreement.

12.2     BUYER

         The Buyer makes the Warranties in favour of the Seller as at the
         Effective Date and as at the Completion Date.  The Warranties are made
         subject to the qualifications made in this Agreement and in the
         Schedules.





                                      16.
<PAGE>   18
12.3     NO WARRANTY UNLESS EXPRESSLY INCLUDED

         (a)     Save as and only to the extent set forth in Clause 12.1, the
                 Seller makes no representations or warranties in respect of
                 any matter or thing and disclaims all liability and
                 responsibility for any representation, warranty, statement,
                 opinion or information made or communicated (orally or in
                 writing) to the Buyer (including, without limiting the
                 generality of the foregoing, any representation, warranty,
                 statement, opinion, information or advice made and
                 communicated to the Buyer by any officer, stockholder,
                 director, employee, agent, consultant, counsel or adviser of
                 the Seller or a tender document) and the Buyer acknowledges
                 and affirms that it has not relied upon any such
                 representation, warranty, statement, opinion or information in
                 entering into or carrying out the transactions contemplated by
                 this Agreement.

         (b)     Subject to the Warranties, the Buyer acknowledges and affirms
                 that it has made its own independent investigation, analysis
                 and evaluation of the geological, geophysical and engineering
                 interpretations, economic valuations and assessment of tax
                 allowances and prospects for development of the Assets and
                 acknowledges and affirms that in making the decision to
                 purchase the Assets, it has relied to that extent upon its
                 independent investigation and those of its representatives,
                 including professional, legal, tax, economic, financial,
                 business and other advisers.

         (c)     The Buyer acknowledges that subject in all respects to the
                 Warranties:

                 (i)      it has made its own enquiries and has undertaken
                          assessments and due diligence with respect to the
                          Company, the Assets and the business conducted by the
                          Company and has satisfied itself as to the Company's
                          interest in the Titles as set out in Schedule 1 and
                          the Joint Venture Contracts set out in Schedule 5,
                          prior to entering into this Agreement;

                 (ii)     it and its advisers have completed a review of the
                          financial records of the Company for the purpose of
                          verifying the accounts of the Company;

                 (iii)    it has not relied on any representation made by or on
                          behalf of the Seller in making its decision to enter
                          into this Agreement other than the Warranties;

                 (iv)     the Seller gives no representation or warranty in
                          respect of the existence or absence of common law or
                          statutory native title rights in respect of the
                          Assets or whether any claim for native title rights
                          exists or will arise in respect of the Assets and the
                          Buyer acknowledges that it has conducted its own
                          enquiries with respect to native title matters;

                 (v)      the Seller is induced to enter into this Agreement in
                          consequence of these acknowledgments; and





                                      17.
<PAGE>   19
                 (vi)     the Seller gives no representation or warranty as to
                          any Tax balances of the Company, and to the extent
                          Tax balances can be calculated from or derived from
                          the Balance Sheet, any warranty and representation in
                          respect of such balances, their calculation or
                          derivation is denied and the Buyer shall have no
                          claim whatsoever against the Seller in respect
                          thereof.

         (d)     The Buyer agrees that it has actual or constructive knowledge
                 of some of the subject matter of the Warranties and any breach
                 of Warranty will not be enforceable against the Seller to the
                 extent it is shown that the inaccuracy, error or omission
                 underlying the alleged breach was known or was constructively
                 known by the Buyer at or prior to the time the Buyer entered
                 into this Agreement.

         (e)     Without prejudice to the generality of the foregoing, the
                 Seller makes no representations or warranties as to:

                 (i)      the amounts of reserves attributable to and the field
                          life of the Assets;

                 (ii)     any geological, geophysical, engineering, economic or
                          other interpretations, forecasts or evaluations; or

                 (iii)    whether any Tax allowances will in fact be deductible
                          in the hands of the Company.

12.4     REASONABLE ENQUIRY

         Where any Warranty is qualified by any reference to the knowledge or
         awareness or belief of any Party, there shall be implied in that
         warranty or representation a warranty that such Party has made
         reasonable enquiries concerning the subject matter of that warranty or
         representation, save that it shall not be deemed to have made
         enquiries of any third party.

12.5     WARRANTIES - DURATION

         The Warranties shall survive the Completion Date for a period of ONE
         (1) year.

12.6     CONSEQUENTIAL LOSS

         Notwithstanding any other provision of the Agreement, a Party shall
         not under any circumstances be liable to the other under, arising out
         of or in any way connected with this Agreement for any consequential
         loss or damage whether arising in contract or tort (including
         negligence or breach of any statutory duty). For the purposes of this
         clause, consequential loss includes but is not limited to, any
         obligation or inability to produce Petroleum, lost production or loss
         of profits howsoever arising.





                                      18.
<PAGE>   20
12.7     LIMITATION ON CLAIMS

         The Buyer's right to claim for and seek indemnity in respect of any
         claim (whether relating to a breach of the Warranties or otherwise
         relating to the subject matter of this Agreement) is limited as
         follows:

         (a)     the Buyer must give written notice to the Seller of the
                 specific claim in question with reasonable details of the
                 relevant claim, including, if possible, the Buyer's estimate
                 of the amount of the claim, on or before the first anniversary
                 of the Completion Date;

         (b)     the Buyer can only bring a claim for breach of a Warranty or
                 otherwise relating to the subject matter of this Agreement if
                 the amount reasonably claimed exceeds (or where there is more
                 than one claim they exceed the aggregate) ONE HUNDRED THOUSAND
                 DOLLARS ($100,000.00);

         (c)     the maximum aggregate amount which the Buyer may recover from
                 the Seller for breach of the Warranties and the indemnities
                 under Clause 12.11 is the aggregate of the Purchase Price and
                 the amount paid by the Buyer in respect of Inter-Company
                 Loans.

12.8     CONDUCT OF CLAIMS

         If the Buyer receives a claim from a third party which may give rise
         to a claim against the Seller under this Agreement, the Buyer must
         within TEN (10) Business Days of receipt, notify the Seller of the
         claim giving full details so far as practicable and, if the Seller
         indemnifies the Buyer and the Company to their reasonable satisfaction
         against all and any costs, charges and expenses which may be incurred
         or for which they may become liable, the Buyer must take such action
         as the Seller reasonably instructs to avoid, dispute, resist, appeal,
         compromise or defend any such claim and any adjudication in respect of
         it.

12.9     BUYER'S REMEDIES

         (a)     Prior to the Completion Date, the Buyer may only rescind this
                 Agreement in accordance with Clause 12.9(b).

         (b)     If not less than THREE (3) Business Days before the Completion
                 Date, the Buyer becomes aware that the Seller is in breach of
                 any of the Warranties of the Seller or any other material
                 provision of this Agreement that has a material adverse effect
                 on the value of the Shares as at the Effective Date, the Buyer
                 shall promptly provide the Seller with written notice
                 containing reasonable details of the said breach in which case
                 the Completion Date shall be automatically extended for a
                 period of TEN (10) Business Days. The Parties will use all
                 reasonable efforts to resolve the matter, failing which the
                 Buyer may not less than THREE (3) Business Days prior to the
                 extended Completion Date, by notice in writing to the Seller
                 elect to:





                                      19.
<PAGE>   21
                 (i)      proceed to Completion on the extended Completion
                          Date, whereupon no Party shall have any further
                          liabilities or obligations to the other whatsoever in
                          respect of the breach notified; or

                 (ii)     (without prejudice to any other right or other remedy
                          it may have and subject always to Clause 12.7)
                          rescind this Agreement.

12.10    NON-MERGER OF WARRANTIES

         No Warranties merge on Completion.

12.11    PRIOR PROPERTIES AND PRIOR SUBSIDIARIES

         (a)     The Seller indemnifies the Buyer against any liability that
                 the Buyer or the Company incurs in connection with:

                 (i)      the business carried on by the Company prior to the
                          Completion Date in respect of the Prior Properties;

                 (ii)     the business carried on by the Prior Subsidiaries
                          during the period when the Company owned the shares
                          or stock in such corporations; and

                 (iii)    the divestment by the Company of the Prior Properties
                          or the Prior Subsidiaries.

         (b)     The indemnity contained in Clause 12.11(a):

                 (i)      shall expire and shall not be enforceable against the
                          Seller unless a claim is notified to the Seller in
                          the manner set out in Clause 12.7 within ONE (1) year
                          of the Completion Date and

                 (ii)     does not extend to any matter relating to Tax whether
                          arising from the Prior Properties, the Prior
                          Subsidiaries, the business of the Company or
                          otherwise and the Buyer releases the Seller in
                          respect to all such matters.

         (c)     The Seller indemnifies the Buyer against any liability (other
                 than a liability for Tax) that the Company incurs in
                 connection with the Perth Basin production licences Nos. L1
                 and L2 and pipeline licences Nos. PL1, PL2, PL3, PL5 and PL23
                 sold to CMS Gas Transmission of Australia provided that the
                 indemnity contained in this Clause 12.11(c) shall expire and
                 not be enforceable against the Seller unless a claim is
                 notified to the Seller in the manner set out in Clause 12.7 on
                 or prior to 30 June 2002.

12.12    RECLAMATION OBLIGATIONS

         All costs, expenses, risks, liabilities and obligations respecting the
         abandonment of any wells which are part of the Assets, closure,





                                      20.
<PAGE>   22
         decommissioning and dismantling the facilities of the Company and any
         reclamation and restoration of all sites shall be borne and paid for
         solely by the Buyer, its successors or assigns, and the Buyer, its
         successors or assigns shall indemnify, defend and save harmless the
         Seller from and against any claims or demands (including breach of
         statutory duty) by any person for or resulting in expense, liability,
         loss, costs, claims or damages direct or indirect (including the
         effects of, and the costs of complying with any order direction, or
         claim of any government or agency having jurisdiction) pertaining to
         the foregoing operations conducted or failed to be conducted by the
         Buyer, its successors or assigns after Completion.

12.13    BUYER'S INDEMNITY-ENVIRONMENTAL DAMAGE

         (a)     The Buyer, its successors or assigns, shall, after Completion,
                 be liable to the Seller for all loss, costs, damages or
                 expenses which the Seller may suffer and, in addition, shall
                 indemnify, defend and save harmless the Seller from and
                 against any claims or demands (including breach of statutory
                 duty) or damages, direct or indirect, before, on and after
                 Completion (including the effects of, and the costs of
                 complying with, any order, direction, or claim of any
                 government or agency having jurisdiction) arising out of or
                 resulting from Environmental Damage caused or alleged to have
                 been caused in respect of the Assets.

         (b)     For the purpose of this clause:

                 ENVIRONMENTAL DAMAGE means any one or more of:

                 (i)      ground water, surface water or aquifer contamination;

                 (ii)     soil contamination;

                 (iii)    corrosion or deterioration of structures, equipment,
                          fences and other property;

                 (iv)     toxic or hazardous substance releases or emissions;

                 (v)      death or injury to human beings caused in whole or in
                          part by any of items (i) through (iv) above;

                 (vi)     death or injury to plants and animals caused in whole
                          or in part by any of items (i) through (iv) above;
                          and

                 (vii)    natural resource damages.

13.      TERMINATION AND DAMAGES

13.1     RIGHT TO TERMINATE

         If not less than THREE (3) Business Days before the Completion Date,
         the Buyer is in breach of any of the Warranties of the Buyer or any
         other material provision of this Agreement such that the interest of
         the Seller under this Agreement is materially adversely affected, then
         the Seller shall promptly





                                      21.
<PAGE>   23
         provide the Buyer with written notice containing reasonable details of
         the said breach in which case the Completion Date shall be
         automatically extended for a period of TEN (10) Business Days. The
         Parties will use all reasonable endeavours to resolve the matter,
         failing which the Seller may not less than THREE (3) Business Days
         prior to the extended Completion Date, by notice in writing to the
         Buyerelect to:

         (a)     complete this Agreement on the extended Completion Date,
                 whereupon no Party shall have any further liabilities or
                 obligations to the other whatsoever in respect of the breach
                 notified; or

         (b)     terminate its obligations under this Agreement, without
                 prejudice to any right or other remedy it may have against the
                 Buyer.

13.2     REMEDY

         The Seller may not give a notice under Clause 13.1(a) or (b) to the
         Buyer where the breach is capable of remedy and has been remedied by
         not less than THREE (3) Business Days before the extended Completion
         Date.

13.3     OTHER TERMINATION RIGHTS

         Either the Buyer or the Seller may terminate this Agreement by written
         notice to the other of them where:

         (a)     the other of them convenes a meeting of its creditors or
                 proposes or enters into a scheme of arrangement or composition
                 with its creditors;

         (b)     there is a liquidation of the other of them;

         (c)     a receiver or receiver and manager is appointed to the other
                 of them;

         (d)     a person holding a security interest over the assets of the
                 other of them takes or attempts to take possession of those
                 assets;

         (e)     an administrator is appointed to the other of them under Part
                 5.3A of the Corporations Law; or

         (f)     the other Party repudiates its obligations under this
                 Agreement.

14.      COSTS, EXPENSES AND DELAYED PAYMENT

14.1     STAMP DUTY

         (a)     The Buyer must pay any stamp duty in respect of the execution,
                 delivery and performance of this Agreement and any agreement
                 or document entered into or signed in contemplation of this
                 Agreement.

         (b)     The Buyer must pay any fine, penalty or other cost in respect
                 of a failure to pay any stamp duty for which it is responsible
                 under Clause 14.1(a), except to the extent that the fine,
                 penalty or other cost is caused by an act or default on the
                 part of the Seller.





                                      22.
<PAGE>   24
         (c)     The Buyer must within FIFTEEN (15) Business Days of the date
                 of this Agreement submit this Agreement for an assessment of
                 stamp duty and use its reasonable endeavours to secure and pay
                 an assessment in respect of this Agreement as soon as
                 practicable and will keep the Seller appraised of progress.
                 The Seller agrees to assist the Buyer when requested and, in
                 particular, to respond to requisitions (if any) for further
                 information.

14.2     COSTS AND EXPENSES

         Subject to Clause 14.1, each Party must pay its own costs and expenses
         in respect of the negotiation, preparation, execution, delivery and
         registration of this Agreement or other Agreement or document entered
         into or signed in connection with the subject matter of this
         Agreement.

14.3     LATE INTEREST

         Without prejudice to any other rights under this Agreement, if any
         amount payable under this Agreement is not paid when due, the
         defaulting Party shall pay interest on a daily basis on such amount
         from the due date of payment (after as well as before judgment) at a
         rate equal to SIX PER CENT (6%) over the Agreed Rate.

15.      CONFIDENTIALITY AND ANNOUNCEMENTS

15.1     AGREED ANNOUNCEMENTS

         No Party shall, without the written consent of the other Party (which
         consent shall not be unreasonably withheld), issue or make any public
         announcement relating to, or disclose anything regarding, this
         Agreement.

15.2     LEGAL REQUIREMENTS

         (a)     If a Party is required to disclose anything in respect of this
                 Agreement in order to comply with:

                 (i)      applicable law; or

                 (ii)     the requirements of any recognised stock exchange on
                          which a Parties' or its Related Body Corporates'
                          shares are listed;

                 then the Parties shall agree on the form and substance of such
                 disclosure and a copy of the same shall be furnished to the 
                 other Parties prior to publication or release.

         (b)     A Party will be deemed to have agreed to the terms of any
                 disclosure if it has not objected to the form or substance of
                 such release within ONE (1) Business Day of it being received
                 by the Party. Each Party agrees to use its best endeavours to
                 approve releases as soon as possible so that Parties are able
                 to comply with statutory or stock exchange requirements.





                                      23.
<PAGE>   25
16.      ASSIGNMENT

         Neither Party may assign the rights under, or the benefit or the
         burden of, this Agreement.

17.      NOTICE

         A notice, demand, consent or authority given or made to a person:

         (a)     must be in writing;

         (b)     may be given or made by:

                 (i)      delivering it to that person personally;

                 (ii)     addressing it to that person and either leaving it
                          at, or posting it to, the address of that person
                          appearing in this Agreement or any other address
                          nominated by that person by notice to the person
                          giving the notice; or

                 (iii)    sending a facsimile copy of the notice to the
                          facsimile copier number nominated by that person by
                          notice to the person giving the notice; and

         (c)     will be deemed to be given or made:

                 (i)      if by leaving it at the address of that person, when
                          left at that address;

                 (ii)     if by post, on the second Business Day after the date
                          of posting (if posted to an address in the same
                          country) or on the seventh Business Day after the
                          date of posting (if posted to an address in another
                          country);

                 (iii)    if by facsimile, on receipt by the sender of a
                          transmission control report from the despatching
                          machine showing the relevant number of pages and the
                          correct destination facsimile machine number and
                          indicating that the transmission had been made
                          without error,

                 but if the result is that a notice would be taken to be given
                 or made on a day which is not a Business Day in the place to
                 which the notice is sent or is later than 4.00pm (local time)
                 it will be taken to have been duly given or made at the
                 commencement of business on the next Business Day in that
                 place.

18.      PROPER LAW

         This Agreement is governed by, and to be interpreted in accordance
         with, the laws of Western Australia and where applicable the laws of
         the Commonwealth of Australia.





                                      24.
<PAGE>   26
19.      JURISDICTION

         The Parties agree to submit to the jurisdiction of the courts of
         Western Australia and if applicable the Commonwealth of Australia.

20.      COUNTERPARTS

         This Agreement may be executed in any number of counterparts each of
         which is an original instrument and all of which constitute one and
         the same instrument.

21.      ENTIRE AGREEMENT

21.1     AGREEMENT CONSTITUTES ENTIRE AGREEMENT

         This Agreement constitutes the entire agreement between the Parties
         with respect to the subject matter of this Agreement and contains all
         of the representations, warranties, covenants and agreements of the
         Parties and supersedes all prior agreements and understandings in
         relation to the subject matter of the Agreement as at the date of this
         Agreement, other than the confidentiality agreement entered into by
         the Parties prior to execution of this Agreement which remains in
         force until Completion.

21.2     NO RELIANCE ON ORAL REPRESENTATIONS

         Each Party acknowledges that it has not relied on any oral statement,
         representation, undertaking, covenant or agreement made before the
         date of this Agreement relating to the subject matter of this
         Agreement and not contained in this Agreement.

22.      MORATORIUM NOT TO APPLY

         To the fullest extent permitted by law, the provisions of a statute
         which would, but for this clause:

         (a)     extend or postpone the date of payment of money; or

         (b)     abrogate, nullify, postpone or otherwise affect any condition;

         under this Agreement do not apply to limit or affect the terms of this
         Agreement.

23.      SEVERANCE

         (a)     If any part of this Agreement is, or becomes, void or
                 unenforceable, that part is, or will be, severed from this
                 Agreement so that all parts that are not, or do not become,
                 void or unenforceable remain in full force and effect and are
                 unaffected by that severance.

         (b)     If any provision of this Agreement, or the application thereof
                 to any person or any circumstance, is invalid or
                 unenforceable, a suitable and equitable provision shall be
                 substituted therefor in order to carry out, so far as may be
                 valid and enforceable, the intent and purpose of such





                                      25.
<PAGE>   27
                 invalid or unenforceable provision and the remainder of this
                 Agreement and the application of such provision to other
                 persons or circumstances shall not be affected by such
                 invalidity or unenforceability, nor shall such invalidity or
                 unenforceability affect the validity or enforceability of such
                 provision, or the application thereof, in any other
                 jurisdiction.

24.      WAIVERS

24.1     FAILURE OR DELAY IS NOT WAIVER

         Failure to exercise or delay in exercising any right, power or
         privilege by a Party does not operate as a waiver of that right, power
         or privilege.

24.2     PARTIAL EXERCISE DOES NOT PRECLUDE FURTHER EXERCISE

         A single or partial exercise of any right, power or privilege by a
         Party does not preclude:

         (a)     any other or further exercise of that right, power or
                 privilege; or

         (b)     the exercise of any other right, power or privilege.

25.      VARIATION

         This Agreement may be varied only by agreement in writing signed by
         the Parties.

26.      FURTHER ASSURANCES

         Each Party must execute and do all acts and things necessary or
         desirable to implement and give full effect to the provisions and
         purpose of this Agreement.

27.      MERGER

         The rights and obligations of the Parties will not merge on the
         completion of any transaction contemplated by this Agreement. They
         will survive the execution and delivery of any assignment or other
         document entered into for the purpose of implementing any such
         transaction.

28.      INTERPRETATION

28.1     REFERENCE TO A STATUTE

         A reference to a statute includes a regulation, by-law, requisition
         and order made under that statute and any amendment to or re-enactment
         of that statute, regulation, by-law, requisition or order for the time
         being in force.

28.2     JOINT AND SEVERAL COVENANTS

         If the Buyer comprises two or more persons, the covenants and
         agreements on their part bind and must be observed and performed by
         them jointly and





                                      26.
<PAGE>   28
         each of them severally and may be enforced against any one or any two
         or more of them.

28.3     LAST DAY NOT A BUSINESS DAY

         When the day or last day for doing an act is not a Business Day in the
         place where that act is to be done, the day or last day for doing the
         act will be the next following Business Day in the place where that
         act is to be done.

28.4     HEADINGS

         Except in the Schedule, headings in this Agreement are for convenience
         and identification of clauses only and do not otherwise affect its
         interpretation.

28.5     REFERENCE TO OTHER DOCUMENT

         Subject to any contrary provision in this Agreement, a reference to
         any other deed, agreement, instrument or contract (including the Joint
         Venture Contracts and the Sales Contracts) includes a reference to
         that other deed, agreement, instrument or contract as amended,
         supplemented or varied from time to time.

28.6     REFERENCE TO A PARTY

         Unless contrary to the sense or context, a reference to a Party
         includes that Party's administrators, personal representatives,
         successors and assigns, and if the Buyer comprises two or more
         persons, administrators, personal representatives, successors and
         assigns of each of those persons.

28.7     SINGULAR, PLURAL AND GENDER

         Where applicable:

         (a)     words denoting the singular include the plural;

         (b)     words denoting the plural include the singular; and

         (c)     words denoting a gender include each gender.

28.8     REFERENCE TO A PERSON AND A BODY CORPORATE

         Where applicable:

         (a)     a reference to a body corporate includes a natural person; and

         (b)     a reference to a person includes a body corporate.

28.9     PROFESSIONAL BODY

         A reference to a professional body includes a successor to or
         substitute for that body.





                                      27.
<PAGE>   29
28.10    PARTIES IN INTEREST

         This Agreement shall inure to the benefit of and be binding upon the
         Parties and their respective successors and permitted assigns. Nothing
         in this Agreement, express or implied, is intended to confer upon any
         person other than the Buyer, the Seller or their respective successors
         or permitted assigns, any rights or remedies under or by reason of
         this Agreement.


EXECUTED BY THE PARTIES

THE COMMON SEAL of AMPOLEX          )
LIMITED ACN 000 113 217 is affixed  )                              [SEAL]
in accordance with its articles of  )
association in the presence of:     )

/s/ Dan P. Haworth                         /s/ Graeme K. Alexander
- ------------------------------             ------------------------------
Signature Director                         Signature Secretary*
                                           
Dan P. Haworth                             Graeme K. Alexander
- ------------------------------             ------------------------------
Print full name of signatory               Print full name of signatory
                                           
*  Delete if not applicable                
                                           
                                           
                                           
SIGNED for and on behalf of         )        
APACHE ENERGY LIMITED               )        
ACN 009 301 964 by                  )        
LISA A FLOYD as duly authorised     )      /s/ Lisa A. Floyd
corporate representative            )      ------------------------------
in the presence of:                 )      Lisa A Floyd
                                           
                                           
/s/ Eve A. Howell                          
- ------------------------------
Witness                                    
                                           




                                      28.
<PAGE>   30
                                  SCHEDULE ONE


1.       TITLES

         Production Licence WA-13-L
         Pipeline Licence WA-5-PL
         Pipeline Licence TPL/12
         Pipeline Licence PL/29
         Pipeline Licence PL/30

2.       INTEREST

         35% interest in the Assets.

3.       SPECIFIED ENCUMBRANCES

         None.





                                      29.
<PAGE>   31
                                  SCHEDULE TWO
                              SELLER'S WARRANTIES


1.       SHARES

1.1      The Seller is the registered holder and beneficial owner of the Shares
         and has power to transfer title to the Shares being the only shares
         issued in the capital of the Company.

1.2      The Shares have been validly issued, are fully paid and are free from
         all Encumbrances.

1.3      There are no restrictions known to the Seller on the transfer of the
         Shares, save that the approval of the board of directors of the
         Company may be required in order to register the transfers.

1.4      The Company has not granted to any person a right to subscribe for or
         acquire or convert any security into any of the Company's unissued
         shares.

1.5      No person has any pre-emptive right with respect to any of the Shares.

1.6      The Company is not under an obligation to issue further shares.

1.7      There are no dividends declared by the Company which are not paid or
         credited to a loan account of a shareholder of the Company.

2.       STATUS OF THE COMPANY

2.1      The copy of the Memorandum and Articles of Association of the Company
         initialled for identification by an officer of the Company and
         produced prior to executing this Agreement is a true copy and includes
         all amendments made up to the date of this Agreement.

2.2      No resolution to alter the Company's Memorandum or Articles of
         Association as produced has been passed since the Effective Date, save
         that Company has converted to a proprietary limited company.

2.3      The Company is not:

         (a)     wound up, no resolution for its winding up has been passed and
                 no meeting of members or creditors has been convened for that
                 purpose;

         (b)     the subject of a winding up application which has been made to
                 a Court, and no event has occurred which would entitle any
                 person to apply to a Court to wind up the Company;

         (c)     a party to a composition or arrangement with any of its
                 creditors;

         (d)     the recipient of a statutory demand under sections 459A-461 of
                 the Corporations Law;





                                      30.
<PAGE>   32
         (e)     in receivership and none of its assets is in the possession of
                 or under the control of a mortgagee or chargee; or

         (f)     subject to administration under Part 5.3A of the Corporations
                 Law,

         and the Seller is not aware of any facts or circumstances which would,
         or are likely to, result in any of the above.

2.4      The Company has not received from the Australian Securities Commission
         any notice or warning of possible cancellation of registration of the
         Company.

3.       BALANCE SHEET

         The Balance Sheet, to the best of the knowledge of the Seller and
         subject to the notes to the accounts and other matters noted:

         (a)     presents a true and fair view of the financial position of the
                 Company as at the Effective Date; and

         (b)     has been prepared and audited in accordance with the relevant
                 accounting standards and generally accepted accounting
                 principles consistently applied.

4.       TITLE TO ASSETS

         The Company has good title to the Assets.

5.       POWER OF ATTORNEY

         The Company has not granted any power of attorney which will be
         effective at or after Completion.

6.       PROCEEDINGS PENDING

6.1      The Company is not engaged in any litigation, arbitration, prosecution
         or other legal proceedings, or any proceedings or hearings before any
         statutory or governmental body, department, board or agency.

6.2      To the Seller's best knowledge and belief there are no facts which are
         likely to give rise to any litigation, arbitration, prosecution or
         other legal proceedings, or any proceedings or hearings before any
         statutory or governmental body, department, board or agency.

6.3      To the Seller's best knowledge and belief there are no facts
         concerning the Prior Properties, Prior Subsidiaries or other assets
         (other than the Assets) owned by the Company prior to the Effective
         Date which are likely to give rise to any claim, litigation,
         arbitration, prosecution or other legal proceeding or proceedings
         which would materially and adversely affect the Company and its
         Assets.





                                      31.
<PAGE>   33
6.4      The Seller gives no warranties and makes no representations whatsoever
         in relation to the existence or absence of any claim, litigation,
         arbitration, prosecution or other legal proceeding or proceedings or
         hearings before any statutory or governmental body, department, board
         or agency relating to any Tax and this Agreement is subject to this
         paragraph.

7.       BUSINESS SINCE EFFECTIVE DATE

         Since the Effective Date:

         (a)     the Company has carried on business and dealt with its
                 property and assets only as a consequence of trading in the
                 ordinary course of business, save as disclosed by the Seller;

         (b)     no alteration has been made to the share capital of the
                 Company;

         (c)     the Company has not declared or paid any dividend or any
                 amount which may be deemed to be a dividend or passed any
                 special resolution;

         (d)     the Company has not granted any Encumbrance over or any part
                 of the Assets other than under the Joint Venture Contracts and
                 the Specified Encumbrances; and

         (e)     the Company has no employees.

8.       CONTRACTS

8.1      To the best of the Seller's knowledge, all agreements binding on the
         Company not entered into in the ordinary course of business of the
         Company have been disclosed to the Buyer.

8.2      To the best of the Seller's knowledge, the Company is not party to any
         agreement which may be terminated by any other party by reason of a
         change in the ownership of the Shares by reason of the change being
         subject to the consent of the other party, which consent has not been
         obtained.

8.3      All material agreements entered into by the Company have been executed
         in accordance with the Company's Articles of Association, are within
         the authority of the Company and are valid and binding on the Company
         and, to the best of the Seller's knowledge and belief, on the other
         parties to those agreements.

9.       SUBSIDIARIES

         The Company has no subsidiaries at the Completion Date.

10.      AUTHORITY

10.1     The Seller is duly incorporated with limited liability and validly
         existing under the laws of its country and state of incorporation.





                                      32.
<PAGE>   34
10.2     The documents which contain or establish the Sellers' constitution
         incorporate provisions which authorise, and all necessary corporate
         action has been taken to authorise, the Seller to execute and deliver
         this Agreement and this Agreement does, and the further documents to
         be executed by the Seller hereunder will, constitute legal, valid and
         binding obligations of the Seller enforceable against them in
         accordance with their respective terms.

10.3     The signing and delivery of this Agreement and the performance of the
         transaction contemplated by this Agreement will not contravene or
         constitute a default under a provision contained in any agreement,
         instrument, law, judgment, order, licence, permit or consent by which
         the Seller is bound.

10.4     The Seller has not incurred any obligation or liability, contingent or
         otherwise, for brokers' or finders' fees in respect of the transaction
         under this Agreement for which the Buyer will have any obligation.

11.      COMPLETENESS OF INFORMATION

         The Seller has provided to the Buyer all information within its
         knowledge which could reasonably be considered to be material in
         relation to the Company, the Shares and the Assets or to their value.

12.      ASSETS

12.1     The Company's legal and beneficial ownership of the Assets is as set
         out in Schedule One, free and clear of all Encumbrances, other than as
         there set out or in the Joint Venture Contracts, Specified
         Encumbrances, the terms of grant of the Titles or under the Petroleum
         Legislation.

12.2     The Joint Venture Contracts are to the best of the knowledge and
         belief of the Seller, a complete list of all material agreements
         constituting or regulating the interests of the Seller in the Titles.

12.3     The Seller has not received any notice of any material breach of its
         obligations under the Joint Venture Contracts or the Sale Contracts.

12.4     The Seller is not in material default under the Joint Venture
         Contracts or the Sale Contracts.

13.      OPERATIONS

         To the best of the knowledge and belief of the Seller:

         (a)     all material conditions and obligations to which the Assets
                 are subject have been complied with and performed; and

         (b)     all Petroleum operations with respect to the Assets have been
                 and are now conducted in accordance with applicable laws and
                 good oilfield practice.





                                      33.
<PAGE>   35
14.      DEFAULT OF OTHER VENTURERS

         The Company has not in the last TWELVE (12) months received any notice
         of default in respect of any other party to the Joint Venture
         Contracts.

15.      COMPLIANCE

         Except in relation to Tax matters:

         (a)     to the best knowledge and belief of the Seller there are no
                 material notices of any public or statutory authority
                 outstanding against the Company; and.

         (b)     the Company has complied in all material respects with the
                 provisions of all laws and regulations and all orders,
                 notices, awards and determinations made by any statutory or
                 other competent authority in any way relating to or binding on
                 the Company or the Assets.





                                      34.
<PAGE>   36
                                 SCHEDULE THREE
                               BUYER'S WARRANTIES


WARRANTIES OF THE BUYER

(a)      The Buyer is duly incorporated with limited liability and validly
         existing under the laws of its country of incorporation.

(b)      The signing and delivery of this Agreement and the performance of the
         transactions contemplated by this Agreement will not contravene or
         constitute a default under the provision contained in any agreement,
         instrument, law, judgment, order, license, permit or consent by which
         the Buyer is bound.

(c)      The Buyer has not incurred any obligation or liability, contingent or
         otherwise, for brokers' or finders' fees in respect of the transaction
         herein provided for which the Sellers will have any obligation.

(d)      The Shares are being purchased by the Buyer for its own account for
         investment and not for purpose of, or with a view to, the resale or
         distribution thereof.

(e)      The documents which contain or establish the Buyer's constitution
         incorporate provisions which authorise, and all necessary corporate
         action has been taken to authorise, the Buyer to execute and deliver
         this Agreement and this Agreement does, and the further documents to
         be executed by the Buyer hereunder will, constitute legal, valid and
         binding obligations of the Buyer enforceable against it in accordance
         with their respective terms.

(f)      The signing and delivery of this Agreement and the performance of the
         transaction contemplated by this Agreement will not contravene or
         constitute a default under a provision contained in any agreement,
         instrument, law, judgment, order, licence, permit or consent by which
         the Buyer is bound.

(g)      The Buyer, on the Completion Date, will have sufficient funds to
         effect Completion and all other transactions contemplated by this
         Agreement.

(h)      Except as specifically set forth in this Agreement, to the best
         knowledge and belief of the Buyer no consent, approval, waiver or
         authorisation is required to be obtained by the Buyer and no notice or
         filing is required to be given by the Buyer with any federal, state,
         local or other governmental authority in connection with the
         execution, delivery and performance by the Buyer of this Agreement.

(i)      The Buyer is not:

         (i)     wound up, no resolution for its winding up has been passed and
                 no meeting of members or creditors has been convened for that
                 purpose;

         (ii)    the subject of a winding up application which has been made to
                 a Court, and no event has occurred which would entitle any
                 person to apply to a Court to wind up the Buyer;





                                      35.
<PAGE>   37
         (iii)   a party to a composition or arrangement with any of its
                 creditors;

         (iv)    the recipient of a statutory demand under sections 459A-461 of
                 the Corporations Law;

         (v)     in receivership and none of its assets is in the possession of
                 or under the control of a mortgagee or chargee; or

         (vi)    subject to administration under Part 5.3A of the Corporations
                 Law.

(j)      The Buyer has not received from the Australian Securities Commission
         any notice or warning of possible cancellation of registration of the
         Company.

(k)      The Buyer is not engaged in any litigation, arbitration, prosecution
         or other legal proceedings, or any proceedings or hearings before any
         statutory or governmental body, department, board or agency which
         would be likely to prejudice the Buyer's performance of its
         obligations under this Agreement.

(l)      There are no facts known to the Buyer which are likely to give rise to
         any litigation, arbitration, prosecution or other legal proceedings,
         or any proceedings or hearings before any statutory or governmental
         body, department, board or agency involving the Buyer which would be
         likely to prejudice the Buyer's performance of its obligations under
         this Agreement.





                                      36.
<PAGE>   38
                                 SCHEDULE FOUR
                                    ACCOUNTS


1.       PREPARATION

         (a)     The initial working capital statement at 30 June 1997 which is
                 based on the Balance Sheet is attached as Schedule Eight.

         (b)     The Seller shall procure that the Company prepares a statement
                 of Working Capital of the Company taking into account the
                 adjustments under Part 2 of this Schedule (WORKING CAPITAL
                 STATEMENT) not less than SEVEN (7) days prior to the
                 Completion Date;

         (c)     The Seller shall prepare the following statements of account:

                 (i)      a profit and loss account in respect of the Assets
                          for the period from the Effective Date to the end of
                          the month immediately prior to the Completion Date
                          (ADJUSTMENT DATE) (PROFIT AND LOSS ACCOUNT); and

                 (ii)     a statement of capital expenditure in respect of the
                          Assets from the Effective Date to the Adjustment Date
                          (CAPITAL STATEMENT).

         (d)     All amounts in US dollars are to be converted to Australian
                 dollars based on the transaction settlement date converted at
                 the Wholesale Market Hedge rate published in the Australian
                 Financial Review.

         (e)     The Working Capital Statement, the Profit & Loss Account and
                 the Capital Statement are referred to as the ACCOUNTS.

2.       WORKING CAPITAL

         (a)     The working capital figure in the Working Capital Statement
                 will take into account the matters set out in this Part in
                 respect of the Assets, the Joint Venture Documents and the
                 hydrocarbons produced from the Assets.

         (b)     For the purpose of the Working Capital Statement, the working
                 capital figure will be based on, but not limited to, the
                 initial items taken from the  initial Working Capital
                 Statement in Schedule Eight, but will be varied, to the extent
                 that any variation is necessary, to take into account:

                 (i)      the purchase price of the hydrocarbons on hand as at
                          00:01 on the Effective Date determined in accordance
                          with paragraphs (c) and (d) (such amounts to be
                          treated as a current asset);





                                      37.
<PAGE>   39
                 (ii)     the amount of any calls payable in respect of the
                          Assets after 00:01 on the Effective Date, which were
                          paid on or before the Effective Date (such amounts to
                          be treated as a current asset);

                 (iii)    the amount of any calls payable in respect of the
                          Assets on or before 00:01 on the Effective Date,
                          which were unpaid on or before the Effective Date
                          (such amounts to be treated as a current liability);

                 (iv)     any other outstanding amount by or to the Company in
                          respect of the Assets that relate to operations of
                          the Company on or before the Effective Date; and

                 (v)      any over contribution or under contribution in
                          respect of the Company recorded in the books of the
                          Operator at the Effective Date.

         (c)     The Company's interest in the stock of hydrocarbons
                 attributable to the Assets on hand as at 00:01 on the
                 Effective Date comprises:

                 (i)      liquids downstream of the wellheads as estimated by
                          the Operator; and

                 (ii)     gas downstream of the low temperature separation
                          plant as estimated by the Operator.

         (d)     The purchase price of the hydrocarbons on hand will be:

                 (i)      for all of such hydrocarbons, the actual proceeds of
                          sale; less

                 (ii)     for all of such hydrocarbons, actual or (where no
                          actual is available) estimated transportation,
                          wharfage and royalty costs incurred through to the
                          point of sale, where estimates are based on the
                          average per barrel implied from actual payments over
                          the preceding three months.

3.       PROFIT & LOSS ACCOUNT

         (a)     The Profit and Loss Account shall take into account:

                 (i)      the amount of operating costs included in any calls
                          paid in respect of the Assets from the Effective Date
                          to the Adjustment Date and the costs of insurances
                          under Clause 8.3 (such amounts to be treated as
                          expenses); and

                 (ii)     the amount of any cash received or entitled to be
                          received in respect of sales of hydrocarbons made
                          pursuant to the Sales Contracts and invoiced in the
                          period from the Effective Date to the Adjustment Date
                          and any other income received in respect of the
                          Assets (such amounts to be treated as revenue).





                                      38.
<PAGE>   40
         (b)     In this Part, if the total of revenue exceeds the total of
                 expenses, then the amount of the difference shall be charged
                 to the Seller Account, otherwise the amount of the difference
                 shall be charged to the Buyer Account.

4.       CAPITAL STATEMENT

         (a)     The Capital Statement shall take into account the amount of
                 any capital cost or receipt comprised or adjusted for in any
                 call paid or received in respect of the Assets from the
                 Effective Date to the Adjustment Date (such amounts to be
                 treated as property, plant and equipment).

         (b)     In this Part, if the total of capital costs under paragraph
                 (a) exceeds the total of capital receipts, then the amount of
                 the difference shall be charged to the Buyer Account,
                 otherwise the amount of the difference shall be charged to the
                 Seller Account.

5.       PROCEDURE TO AGREE ACCOUNTS

         (a)     Not less than SEVEN (7) Business Days prior to the projected
                 Completion Date, the Seller agrees to submit the Accounts to
                 the Buyer. The Seller will provide supporting documentation.

         (b)     Within FOUR (4) Business Days of the date on which the Seller
                 provides the Accounts (or such shorter time as the parties
                 agree), the Buyer agrees to advise the Seller in writing as to
                 any amounts it does not agree to, including its reasons.

         (c)     The Parties will in good faith seek to reach agreement without
                 delay on any amounts not agreed to between them.

         (d)     If no notice is given by the Buyer under paragraph (b) of this
                 Part, then the Accounts will be treated as the Accounts for
                 the purposes of determining the amounts to be paid or allowed
                 at Completion.

         (e)     If a notice is given by any Party under paragraph (b) of this
                 Part and the Parties do not resolve the matter within THREE
                 (3) Business Days prior to Completion, then the Parties will
                 pay at Completion the amounts in the Buyer Account and the
                 Seller Account not in dispute under clause 4 of the Agreement.

         (f)     If any amount is not agreed nor paid or allowed at Completion,
                 then either Party may give notice to the other that the matter
                 be referred to an Independent Accountant. The notice must
                 suggest a person to be the Independent Accountant and process
                 set out in Schedule 6 must be followed.

         (g)     If a reference is made to the Independent Accountant under
                 paragraph (f) of this Part, the terms of reference must be to
                 resolve the matters in dispute in accordance with the
                 principles set out in Parts 1, 2, 3 and 4 of this Schedule as
                 soon as possible. The Buyer and Seller must co-





                                      39.
<PAGE>   41
                 operate and make information available as requested by the
                 Independent Accountant. The Buyer and the Seller must ensure
                 that the Company promptly makes available such information as
                 the Independent Accountant may request in relation to the
                 matters in dispute. All correspondence between the Independent
                 Accountant and any Party must be promptly copied to the other
                 Party.

         (h)     The Independent Accountant must issue a certificate as to his
                 determination of the matters referred to him and of the
                 Accounts, adjusted (if necessary) to take account of his
                 determinations. The Buyer and Seller agree that in carrying
                 out this role, the Independent Accountant acts as expert and
                 not arbitrator and that, in the absence of fraud or mistake or
                 manifest error, the certificate issued by the Independent
                 Accountant will be final and binding on them.

         (i)     The Buyer and the Seller will bear equally the costs of the
                 Independent Accountant.

6.       POST COMPLETION ADJUSTMENTS FOR PERIOD BETWEEN ADJUSTMENT DATE AND
         COMPLETION

         (a)     Within THIRTY (30) days after the end of the month in which
                 Completion occurs the Seller will prepare the Accounts and
                 submit them to the Buyer, in each case made up to the
                 Completion Date.

         (b)     The Parties will follow the procedures set out in Part 5 of
                 this Schedule to determine the Buyer Account and the Seller
                 Account as at the Completion Date.

         (c)     Any difference between the Buyer Account and the Seller
                 Account at the Adjustment Date and at the Completion Date will
                 be paid to the Party entitled by the other Party within FIVE
                 (5) Business Days of determination of those Accounts.





                                      40.
<PAGE>   42
                                 SCHEDULE FIVE

JOINT VENTURE CONTRACTS

Interim Joint Operating Agreement - Production Licence WA-13-L dated 30 May
1996 between the Company, Apache Oil Australia Pty Ltd, Santos (BOL) Pty Ltd
(formerly Parker & Parsley Australasia Limited) and Western Mining Corporation
Limited;

Harriet Joint Venture and East Spar Joint Venture Access Agreement (Varanus
Island) dated 12 December 1996 between Ampolex (Western Australia) Inc.,
Ampolex Varanus Pty Ltd, Apache Northwest Pty Ltd, Hardy Petroleum Limited,
Kufpec Australia Pty Ltd, Tap (Harriet) Pty Ltd, Novus UK (Harriet) Limited,
New World Oil & Developments Pty Ltd, the Company, Apache Oil Australia Pty
Ltd, Santos (BOL) Pty Ltd, WMC Resources Ltd and Apache Energy Limited;

Assignment, Farmin/Farmout, Assumption, novation and covenant documentation
registered as dealings against the Titles, or any predecessor title thereof,
and instruments of transfer of title registered against the Titles, or any
predecessor title thereof, in the Registers maintained under the Petroleum
Legislation.

SALES CONTRACTS

Grant of Full-Haul Capacity dated 16 August 1995 between the Company, Apache
Oil Australia Pty Ltd, Western Mining Corporation Limited, Parker & Parsley
Australasia Limited and Gas Corporation (trading as AlintaGas);

Interim Gas Agreement dated on or about 19 February 1996 between the Company,
Apache Oil Australia Pty Ltd, Western Mining Corporation Limited, Parker &
Parsley Australasia Limited, Ampolex (Western Australia), Inc., Ampolex Varanus
Pty Limited, Apache Northwest Pty Ltd, Hardy Petroleum Limited, Kufpec
Australia Pty Limited, Marubeni Oil Australia Pty Limited, Novus UK (Harriet)
Limited and New World Oil and Developments Pty Limited;

Gas Sale Agreement - Kwinana Nickel Refinery dated on or about 11 June 1996
among WMC Resources Ltd, the Company, Apache Oil Australia Pty Ltd (the
Contract was not executed by Santos (BOL) Pty Ltd);

Gas Sale Agreement - Goldfields Operations between WMC Resources Ltd, the
Company, Apache Oil Australia Pty Ltd and Santos (BOL) Pty Ltd;

Westlime Dongara Lime Project - Gas Supply Heads of Agreement dated 30 October
1996 between AGL Gas Trading Pty Limited, WMC Resources Ltd, the Company,
Apache Oil Australia Pty Ltd and Santos (BOL) Pty Ltd;

Gas Sale Agreement dated 29 August 1997 between Western Power and the Company,
Apache Oil Australia Pty Ltd and Santos (BOL) Pty Ltd;

Gas Sale Agreement dated 3 September 1997 between Western Power and Fletcher
Challenge Southwest Cogeneration Pty Ltd and the Company, Apache Oil Australia
Pty Ltd and Santos (BOL) Pty Ltd; 

Condensate Sale Agreement dated 23 December 1996 between Glencore International
AG and the Company.





                                      41.
<PAGE>   43
                                  SCHEDULE SIX
                           PROCEDURES FOR INDEPENDENT
                            ACCOUNTANT DETERMINATION


1.       REFERRALS TO EXPERT

         Wherever in this Agreement any matter is to be referred to the
         Independent Accountant, then the terms of this Schedule shall apply.

2.       APPOINTMENT

         The procedure for appointing the Independent Accountant is as follows:

2.1      The disputing Party must give written notice including details of the
         matter to be resolved by the Independent Accountant to the other
         Party.

2.2      If the matter is not resolved within FOURTEEN (14) days from the date
         of the notice, the Parties shall agree on a single accountant to
         determine the dispute or, if no agreement is reached within FIVE (5)
         Business Days, a chartered accountant nominated by the President of
         the Institute of Chartered Accountants in Australia being a person who
         is not a partner, consultant or employee of the Buyer's accountants or
         the Seller's accountants and at which time is not or which firm for he
         or she works is not retained by the Buyer, the Seller or any of their
         Related Bodies Corporate in any capacity whatsoever.

2.3      DUTY OF DISCLOSURE

         Any person appointed as the Independent Accountant shall fully
         disclose any interest which may conflict with the appointment before
         accepting such appointment and, with the agreement of both Parties,
         shall be entitled to act as such expert, notwithstanding that he or
         she has, or may have, some interest which conflicts with such
         appointment.

2.4      POWERS AND DUTIES

         An Independent Accountant shall, within TEN (10) days of his or her
         acceptance of the appointment, fix a reasonable time and place for
         receiving submissions or information from the Parties or any other
         persons that he or she may think fit and may make further enquiries
         and require such other evidence as he or she considers necessary and
         shall determine the matter with all due diligence.

2.5      NOT ARBITRATOR

         The Independent Accountant shall not be an arbitrator but shall give
         his or her decision as an expert and the provisions of the Commercial
         Arbitration Act 1985 shall not apply to the expert, the determination
         or the determination procedure.





                                      42.
<PAGE>   44
2.6      DETERMINATION BINDING

         The Independent Accountant's determination shall be final and binding
         upon the Parties except for fraud, mistake or manifest error.

2.7      COSTS

         Each Party shall bear the costs and expenses of any consultants,
         witnesses and employees retained by it in connection with the matter,
         but the costs and expenses of the Independent Accountant shall be
         apportioned equally between the Parties.

2.8      REMOVAL OF INDEPENDENT ACCOUNTANT

         If the Independent Accountant has not made a determination within
         SIXTY (60) days of his appointment, either Party may, by notice,
         terminate such appointment.

2.9      APPOINTMENT OF REPLACEMENT

         In the event of such termination, a new Independent Accountant shall
         be appointed within TEN (10) days and the matter determined in
         accordance with this Schedule.

2.10     CONTINUED PERFORMANCE OF OBLIGATIONS

         The referral of a matter to the Independent Accountant shall not
         affect the obligations of the Parties to perform or pay any amount
         otherwise due in accordance with the terms and conditions of the
         Agreement.





                                      43.
<PAGE>   45
                                 SCHEDULE SEVEN
                SPECIAL PURPOSE FINANCIAL REPORT OF THE COMPANY
                               AS AT 30 JUNE 1997





                                   [OMITTED]





                                      44.
<PAGE>   46
                                 SCHEDULE EIGHT
                           WORKING CAPITAL STATEMENT





                                   [OMITTED]





                                      45.

<PAGE>   1





                                  EXHIBIT 2.2










                              SHARE SALE AGREEMENT
                        AMPOLEX (WESTERN AUSTRALIA) INC

                           AMPOLEX (PNG HOLDINGS) INC
                                Acn 000 113 217

                                      and

                               APACHE CORPORATION





<PAGE>   2





THIS AGREEMENT is made        8th        October                            1997

BETWEEN

AMPOLEX (PNG HOLDINGS) INC a company incorporated in Delaware having its
registered office at 1013 Center Road, City of Wilmington, County of New
Castle, Delaware, United States of America (Seller)

AND

APACHE CORPORATION (a corporation incorporated under the laws of Delaware,
United States of America) of 2000 Post Oak Boulevard, Suite 100, Houston, Texas
77056 (Buyer)

RECITALS:

A.        The Company is engaged in the business of producing oil and gas in
          Western Australia.

B.        The Seller is the legal and beneficial owner of the Shares being the
          whole of the issued share capital of the Company.

C.        The Seller has agreed to sell the Shares to the Buyer, and the Buyer
          has agreed to purchase the Shares from the Seller on the terms and
          conditions set out in this Agreement.

The Parties AGREE:

1.        DEFINITIONS

1.1       Unless otherwise required by the context or subject matter:
          
          ADJUSTMENT AMOUNT is defined in clause 6.4;

          AGREED RATE means the THIRTY (30) day Bank Bill Swap Reference Rate
          (source Bloomberg) published in the Australian Financial Review in
          respect of the first Business Day of each month or part month for
          which interest is to be calculated;

          AGREEMENT means this agreement as amended, supplemented or varied
          from time to time;

          ASSETS means the interest of the Company as listed in Schedule One
          and in Schedule Five in and under:



                                      1.
<PAGE>   3
          (a)    the Titles and all other rights, titles and interests in the
                 Titles subject to the terms and conditions of their grant;

          (b)    the Joint Venture Contracts, including any joint venture
                 property held under those contracts;

          (c)    the Information; and

          (d)    all other miscellaneous assets, rights, property and interests
                 associated or employed in relation to the Assets, including
                 the right to produce Petroleum in accordance with that
                 interest;

          BALANCE SHEET means the balance sheet of the Company as audited by
          Ernst & Young annexed as Schedule 7 prepared on the basis set out in
          the notes to the Balance Sheet;

          BANK ACCOUNT means any bank account in the name of the Company;

          BUSINESS DAY means a day (during the hours of 9.00am to 5.00pm Perth
          time) on which trading banks are open for business in Perth, Western
          Australia;

          BUYER ACCOUNT means an account of amounts owed by the Buyer to the
          Seller determined under Schedule 4;

          BUYER'S SOLICITORS means Arthur, Robinson & Hedderwicks of 530
          Collins Street, Melbourne, Victoria;

          COMPANY means Ampolex (Western Australia) Inc (ARBN 009 473 241);

          COMPLETION means completion of the sale and purchase of the Shares
          under Clause 9;

          COMPLETION DATE means the later of:

          (a)    14 November 1997; or

          (b)    the day falling FIVE (5) Business Days after the Conditions
                 are satisfied; or

          such other date as the Parties may agree in writing;

          CONDITION means any conditions specified in clauses 3 and 4 inclusive
          and CONDITIONS means all of them;
        
          DOLLARS or $ means Australian dollars unless otherwise stated;

          EFFECTIVE DATE means 00.01am, 1 July 1997 (Perth time);





                                       2.

<PAGE>   4
          ENCUMBRANCE means a mortgage, charge, whether fixed or floating, bill
          of sale, pledge, lien, charging order, stop order, writ of execution,
          title retention or conditional sales agreement, hire or hire purchase
          agreement, lease, licence to use or occupy, option, restriction as to
          transfer, use or possession, easement, caveat and the claim stated in
          that caveat, equity interest and any other security interest or other
          third party right or interest;

          GOVERNMENTAL AGENCY means any government or governmental,
          semi-governmental, administrative, fiscal or judicial body,
          department, commission, authority, tribunal, agency or entity;

          INDEPENDENT ACCOUNTANT means the chartered accountant referred to in
          Schedule Six;

          INFORMATION means geological, geophysical or technical information
          within the custody or control of the Company being material
          information that relates to the presence, absence or extent of
          hydrocarbon deposits in the area of the Assets and has been obtained
          from the exploration and prospecting for or production of
          hydrocarbons within Assets including, without limitation, the books,
          records, seismic and interpretive data, notes, drawings, maps and
          other information (in various media) related to the Assets;

          INTERIM PERIOD means the period between the Effective Date and the
          Completion Date;

          JOINT VENTURE means all or any of, as the context requires, the
          relationships established under the Joint Venture Contracts;

          JOINT VENTURE CONTRACTS means the contracts listed as such in
          Schedule Five;

          OPERATOR means Apache North West Pty Ltd except in relation to
          Exploration Licence WA-192-P, in respect of which Tap (Harriet) Pty
          Ltd has been appointed the Operator;
                   
          OTHER AGREEMENTS means:

          (a)    an agreement entered into on the date of this Agreement
                 between Ampolex Limited and the Buyer or a Related Body
                 Corporate of the Buyer for the sale of the issued shares in
                 Ampolex (A.O.E.) Pty Limited;

          (b)    an agreement entered into on the date of this Agreement
                 between Ampolex Limited and the Buyer or a Related Body
                 Corporate of the Buyer for the sale of the issued shares in
                 Ampolex Varanus Pty Limited;

          PARTY means the Seller or the Buyer according to the context and
          Parties means both the Seller and the Buyer;





                                       3.

<PAGE>   5
          PETROLEUM has the meaning given in the Petroleum (Submerged Lands)
          Act (WA) 1982;

          PETROLEUM LEGISLATION means the Petroleum Act (WA) 1967, the
          Petroleum (Submerged Lands) Act (Cth) 1967, the Petroleum (Submerged
          Lands) Act (WA) 1982, the Petroleum Pipelines Act (WA) 1969 any other
          Act of Parliament with which each Act is incorporated, as well as all
          regulations, administrative directions and determinations made under
          any of those Acts;

          PURCHASE PRICE means the cash consideration of ONE HUNDRED AND THIRTY
          TWO MILLION NINE HUNDRED AND SEVEN THOUSAND SIX HUNDRED AND EIGHTEEN
          DOLLARS AND FIFTY NINE CENTS ($132,907,618.59) (which amount includes
          working capital as at the Effective Date) as adjusted in accordance
          with Clause 6 and Schedule Four, plus interest at the Agreed Rate
          calculated daily and compounded monthly during the Interim Period;

          RELATED BODY CORPORATE has the meaning given to that expression in
          the Corporations Law;
                
          SALE means the sale and purchase of the Shares in accordance with the
          terms of this Agreement;

          SALES CONTRACTS means the contracts listed as such in Schedule 5;

          SCHEDULE means a schedule to this Agreement;

          SELLER ACCOUNT means an account of amounts owed by the Seller to the
          Buyer determined under Schedule 4;

          SELLER'S SOLICITORS means Freehill Hollingdale & Page of 140 St
          Georges Terrace, Perth, Western Australia;

          SHARES means the 10,000 partly paid shares in the Company having a
          par value of US$2,500.00 being all the issued shares in the capital
          of the Company;

          SPECIFIED ENCUMBRANCES means the encumbrances specified in Schedule
          One;

          TAX means all federal, state, local or foreign taxes and charges
          including but not limited to income, gross receipts, windfall
          profits, goods and services, value added, transfer, property, sales,
          production, use, license, excise, franchise, withholding or similar
          taxes, together with any interest, additions or penalties and any
          interest in respect of such additions or penalties;

          TITLES means the petroleum titles and licences specified in Schedule
          One; and





                                       4.

<PAGE>   6
          WARRANTIES mean the warranties and representations set out in:-

          (a)    Schedule Two in the case of the Seller; and

          (b)    Schedule Three in the case of the Buyer.

2.        SALE SUBJECT TO CONDITIONS

          The Sale is conditional on satisfaction of each and every Condition.

3.        HART-SCOTT-RODINO CONDITION

          This Agreement is subject in all respects to and conditional upon
          compliance by the Parties with the Hart- Scott-Rodino Antitrust
          Improvements Act of 1976 (HSR Act), and rules and regulations
          promulgated pursuant thereto, to the extent the HSR Act, rules and
          regulations are applicable to the transactions contemplated by this
          Agreement and the Other Agreements. The Parties shall make such
          filings with and provide such information to the Federal Trade
          Commission as are required in connection with the HSR Act as soon as
          practicable after the date of this Agreement.

4.        FIRB CONDITION

4.1       DEFINITION

          In this subclause:

          ACT means the Foreign Acquisitions and Takeovers Act 1975; and

          TREASURER means the Treasurer of Australia.

4.2       SALE SUBJECT TO APPROVAL

          The Sale is conditional on the Treasurer either:

          (a)    advising the Buyer that the Treasurer has no objection to the
                 acquisition of the Shares by the Buyer and the transactions
                 contemplated by the Other Agreements either:

                 (i)       unconditionally; or

                 (ii)      subject to conditions with which the Buyer (or its
                           Related Body Corporate, as the case may be) is
                           willing to comply; or

          (b)    ceasing to be empowered under the Act to make an order
                 prohibiting the acquisition of the Shares by the Buyer and the
                 transactions contemplated by the Other Agreements;

          whichever occurs first.





                                       5.

<PAGE>   7
4.3       NOTICE TO BE GIVEN TO TREASURER

          The Buyer must:

          (a)    give notice to the Treasurer under section 25 of the Act in
                 the prescribed form; and

          (b)    comply with all directions on that form;

          within TEN (10) Business Days from the date of this Agreement.

4.4       PARTIES' OBLIGATIONS

          (a)    The Buyer must use  all reasonable endeavours to obtain the
                 approval of the Treasurer to the Sale under the Act.

          (b)    The Parties must (and the Seller must ensure that the Company
                 will) do all things and provide all information and documents
                 required by the Treasurer or the Foreign Investment Review
                 Board in connection with the application for approval of the
                 Sale under the Act as soon as reasonably practicable after
                 being notified of the required things, information or
                 documents.

4.5       BENEFIT OF CONDITION

          This Condition:

          (a)    is for the benefit of the Seller and the Buyer; and

          (b)    may not be waived.

4.6       CONDITION NOT FULFILLED

          If approval of the Treasurer is denied,  then:

          (a)    the Sale will terminate automatically without notice; and

          (b)    subject to the rights of either Party in respect of any
                 antecedent breach of the provisions of this Agreement:

                  (i)      neither the Seller nor the Buyer will have any claim
                           against the other; and

                 (ii)      this Agreement, other than this subclause, will have
                           no further effect.





                                       6.

<PAGE>   8
5.        SALE AND PURCHASE

          At Completion, the Seller agrees to sell and transfer to the Buyer,
          and the Buyer agrees to purchase from the Seller the Shares free from
          Encumbrances for the Purchase Price on the terms and conditions of
          this Agreement.

6.        CONSIDERATION

6.1       PURCHASE PRICE

          The Buyer shall pay the Seller the Purchase Price subject to any
          adjustments required by this Agreement.

6.2       BUYER ACCOUNT

          The Buyer must pay to the Seller in addition to the Purchase Price
          the amount charged to the Buyer Account plus interest at the Agreed
          Rate calculated daily and compounded monthly.

6.3       SELLER ACCOUNT

          The Seller must pay by way of a deduction to the Purchase Price the
          amount charged to the Seller Account plus interest at the Agreed Rate
          calculated daily and compounded monthly.

6.4       PAYMENT

          Other than in respect of the amounts agreed or determined under
          Schedule Four, the payments under this Clause shall be paid at
          Completion and the Buyer Account and the Seller Account may be offset
          so that only one payment is made as between the Buyer and the Seller
          (Adjustment Amount).

6.5       POST COMPLETION/FINAL ADJUSTMENT

          Any matters not finally determined by and paid on the Completion Date
          will be resolved and payment made pursuant to the procedure described
          in Schedule Four.

6.6       FURTHER ADJUSTMENT

          If at any time during the period of THREE (3) years following the
          Completion Date the:

          (a)    Buyer becomes:

                 (i)       entitled to or receives funds, revenues, refunds,
                           credits or payments; or

                 (ii)      liable to pay (and subject to this clause, does or
                           agrees to pay) costs, expenses and expenditure;





                                       7.

<PAGE>   9
                 which are attributable to the Assets and relate to the period
                 before the Effective Date; or

          (b)    Seller becomes:

                 (i)       entitled to or receives funds, revenues, refunds,
                           credits or payments; or

                 (ii)      liable to pay (and subject to this clause, does or
                           agrees to pay) costs, expenses and expenditure;

                 which are attributable to the Assets and relate to the period
                 after the Effective Date;

          (in all cases, which amounts or liabilities were not otherwise
          specifically adjusted for in this Agreement), in an amount or amounts
          aggregating or exceeding not less than TEN THOUSAND DOLLARS
          ($10,000.00), then

          (c)    the Buyer shall account to the Seller within THIRTY (30) days
                 of such adjustments in respect of paragraphs 6.6(a)(i) and
                 6.6(b)(ii); and

          (d)    the Seller shall account to the Buyer within THIRTY (30) days
                 of such adjustments in respect of paragraphs 6.6(a)(ii) and
                 6.6(b)(i),

          for such funds, revenues, liabilities, costs, expenses, refunds,
          credits or payments and, where an amount relates partially to periods
          before and after the Effective Date, then the amount shall be
          equitably apportioned between the Seller and the Buyer. A Party shall
          be entitled to set off amounts payable by the other Party in making
          account to that other Party. A reference to the Buyer and the Seller
          in paragraphs (a) and (b) of this Clause includes a reference to the
          Company, where the Company receives an amount or incurs a liability
          to be adjusted under this clause.

7.        ACCESS TO COMPANY RECORDS

          From the date of this Agreement, the Seller shall and shall cause the
          Company to allow reasonable access by the Buyer to all of the
          Company's books, accounts and documents in connection with the
          Company and the Shares, and information concerning the Company
          relevant to the Sale.

8.        PERIOD BEFORE COMPLETION

8.1       CARRYING ON OF BUSINESS

          The Seller shall cause that between the date of execution of this
          Agreement and the Completion Date:





                                       8.

<PAGE>   10
          (a)    the Company informs and consults with the Buyer on all
                 material matters relating to the conduct of the business of
                 the Company and will procure that such business is conducted
                 in a diligent and ordinary and usual manner. In particular,
                 but without prejudice to the generality of the foregoing, the
                 Seller will procure that the Company consults with the Buyer
                 before the Company:

                 (i)       approves any new or varied programme and budget of
                           operations;

                 (ii)      approves any drilling operations which are not at
                           the date of this Agreement approved or identified in
                           an approved programme and budget;

                 (iii)     approves any other matter likely to affect in any
                           material respect the nature or extent of expenditure
                           obligations of the Company;

                 (iv)      in any other respect, exercises any voting right
                           under any Joint Venture Contract;

          (b)    the Company does not acquire or dispose of any Asset, other
                 than acquisitions or disposals of Petroleum, stocks or
                 receivables in the ordinary course of business without the
                 prior written consent of the Buyer;

          (c)    the Company does not create any Encumbrances over any of the
                 Assets without the prior written consent of the Buyer;

          (d)    the Company pays when due all cash calls under the Joint
                 Venture Contracts;

          (e)    the Company does not vary the terms of sale of its share of
                 Petroleum derived from the Assets pursuant to the Sale
                 Contracts;

          (f)    without the prior written approval of the Buyer (which
                 approval shall not be unreasonably withheld), the Company will
                 not:

                 (i)       give notice of or otherwise institute in any sole
                           risk or non-consent operation;

                 (ii)      farm-out the Assets;

                 (iii)     surrender or relinquish of any part of the Assets;
                           or

                 (iv)      execute any instrument amending, waiving or
                           cancelling any provision of the Joint Venture
                           Contracts;

          (g)    the Company provides to the Buyer copies of all material
                 notices issued by the Operator in respect of the Assets;

          (h)    the Company does not issue any shares, options or securities
                 which are convertible into shares in the Company;





                                       9.

<PAGE>   11
          (i)    the Company does not engage any employees;

          (j)    the Company does not alter its memorandum or Articles of
                 Association without the prior written consent of the Buyer;

          (k)    the Company does not incur any liabilities, enter into any
                 contract or commitment or engage in any activity other than in
                 the ordinary course of business; and

          (l)    the business of the Company is conducted so as to comply in
                 all material respects with all applicable laws and regulations

          PROVIDED THAT the Seller will not be liable to the Buyer for any
          breach of an obligation imposed in this Clause 8.1 which arises from
          any course of action, to the extent that the Seller has consulted
          with the Deputy Managing Director of Apache Energy Limited prior to
          undertaking such course of action and she has not objected in writing
          as soon as practicable after such consultation.

8.2       ACCESS TO INFORMATION

          (a)    In addition to its obligations under Clause 8.1, the Seller
                 will procure that the Company will, subject to any
                 confidentiality restrictions contained in the Joint Venture
                 Contracts and this Agreement and subject to reasonable notice,
                 give the Buyer reasonable access to the Information and any
                 other matters relating to the Assets during normal working
                 hours and provide copies thereof, at the Buyer's cost.

          (b)    In exercising its rights under Clause 8.2(a), the Buyer will
                 not unreasonably interfere with the business or operations of
                 the Seller or the Company.

          (c)    If this Agreement is terminated for whatever reason, the Buyer
                 must promptly return all Information to the Seller.


8.3       INSURANCE

          During the Interim Period, the Seller will ensure that the Company
          maintains the insurances taken out in respect of the Assets as at the
          Effective Date. These insurances will be at the cost of the Buyer and
          adjusted for under Schedule 4.

9.        COMPLETION

9.1       COMPLETION LOCATION

          Completion will take place at the Seller's Solicitors' office.

9.2       COMPLETION DATE

          The Parties must effect Completion on the Completion Date at a time
          agreed by





                                      10.

<PAGE>   12
          the Buyer and the Seller.

9.3       SELLER'S OBLIGATIONS

          At Completion, the Seller must deliver to the Buyer:

          (a)    a duly executed but unstamped transfer of the Shares, together
                 with the relevant share certificates;

          (b)    (i)       the common seal and any duplicate or official seals;

                 (ii)      any Memorandum and Articles of Association of the
                           Company in the possession of the Seller;

                 (iii)     all minutes of meetings of directors and
                           shareholders of the Company;

                 (iv)      all registers of the Company;

                 (v)       copies of all income tax returns lodged by the
                           Company before the Completion Date and supporting
                           tax return work papers in possession of the Company;

                 (vi)      all books, ledgers, records and other documents and
                           data of the Company in either written or electronic
                           form; and

                 (vii)     a signed notice to each Purchaser under the Sale
                           Contracts nominating a new Bank Account into which
                           proceeds of sale of Petroleum can be made;

          (c)    a legal opinion by the Seller's Solicitors (or by an attorney
                 qualified to give such an opinion in the jurisdiction in which
                 the Seller is incorporated) in a form reasonably satisfactory
                 to the Buyer and the Buyer's Solicitors stating that this
                 Agreement is, and will be, enforceable against the Seller in
                 all respects in accordance with its terms;

          (d)    a certificate signed on behalf of the Seller by two authorised
                 officers (AUTHORISED OFFICERS) stating that all the
                 representations and warranties given by the Seller in this
                 Agreement are true and correct as at Completion and that the
                 Seller is not in breach of any of its obligations under this
                 Agreement;

          (e)    copies of board resolutions certified as true and correct by
                 an Authorised Officer in which the directors of the Seller
                 authorise the execution of this Agreement and the performance
                 of the Seller of the transactions contemplated by this
                 Agreement;





                                      11.

<PAGE>   13
          (f)    certificates of incumbency in respect of each Authorised
                 Officer confirming the authority of each of them to sign the
                 certificate referred to in Clause 9.3(e) on behalf of the
                 Seller; and

          (g)    the Adjustment Amount, if the Seller Account plus interest at
                 the Agreed Rate calculated daily and compounded monthly is
                 greater than the Buyer Account plus interest at the Agreed
                 Rate calculated daily and compounded monthly.

9.4       OTHER OBLIGATIONS OF SELLER ON COMPLETION

          As part of Completion, on payment of the Purchase Price and subject
          to Clause 9.5(a), payment of the Adjustment Amount to the Seller, the
          Seller shall cause the directors of the Company to hold a meeting
          with effect at Completion at which the directors, in accordance with
          the Company's articles of association:

          (a)    appoint the Buyer's nominees as additional directors of the
                 Company;

          (b)    appoint the Buyer's nominee as an additional secretary of the
                 Company;

          (c)    approve for registration, subject to payment of stamp duty,
                 the transfer of the Shares to the Buyer;

          (d)    (i)       authorise the signature of all authorities necessary
                           to revoke all existing authorities to bankers in
                           relation to the operation of the Bank Accounts; and

                 (ii)      appoint, in the manner the Buyer directs, the
                           Buyer's nominees as the persons authorised to
                           operate the Bank Accounts.

          (e)    table and accept resignations of:

                 (i)       the public officer;

                 (ii)      the secretary, other than the secretary nominated by
                           the Buyer; and

                 (iii)     the directors, other than the directors nominated by
                           the Buyer;

                 to take effect on and from the close of business of the
                 meeting; and

          (f)    sign all forms required to be signed by the outgoing directors
                 and secretary under the Corporations Law.

9.5       THE BUYER'S OBLIGATIONS AT COMPLETION

          At Completion, the Buyer must:





                                      12.

<PAGE>   14
          (a)    by means of confirmed electronic funds transfer to a bank
                 account in the name of the Seller as nominated by the Seller
                 to the Buyer for value at Completion in Australian dollars pay
                 to the Seller the Purchase Price and, if the Buyer Account
                 plus interest at the Agreed Rate calculated daily and
                 compounded monthly is greater than the Seller Account plus
                 interest at the Agreed Rate calculated daily and compounded
                 monthly, the Adjustment Amount; and

          (b)    deliver to the Seller:

                 (i)       a legal opinion by the Buyer's Solicitors (or by an
                           attorney qualified to give such an opinion in the
                           jurisdiction in which the Buyer is incorporated) in
                           a form reasonably satisfactory to the Seller and the
                           Seller's Solicitors, stating that this Agreement is,
                           and will be, enforceable against the Buyer in all
                           respects in accordance with its terms;

                 (ii)      a certificate signed on behalf of the Buyer by two
                           authorised officers (AUTHORISED OFFICERS) stating
                           that all the representations and warranties given by
                           the Buyer in this Agreement are true and correct as
                           at Completion and that the Buyer is not in breach of
                           any of its obligations under this Agreement;

                 (iii)     copies of board resolutions certified as true and
                           correct by an Authorised Officer in which the
                           directors of the Buyer authorise the execution of
                           this Agreement and the performance of the Buyer of
                           the transactions contemplated by this Agreement; and

                 (iv)      certificates of incumbency in respect of each
                           Authorised Officer confirming the authority of each
                           of them to sign the certificate referred to in
                           paragraph (ii) on behalf of the Buyer.

9.6       COMPLIANCE

          Neither the Buyer nor the Seller will be obliged to proceed to
          Completion unless:

          (a)    there is no material breach of Clause 8 which remains
                 unremedied; and

          (b)    the other of them complies with all of its obligations under
                 this Clause 9.

9.7       OTHER DOCUMENTS

          As soon as possible after Completion, the Seller will cause to be
          delivered at the Buyer's cost to the Buyer:

          (a)    all technical and other data, books, records, accounts,
                 contracts, maps, notes, drawings and other information
                 (regardless of form) constituting the





                                      13.

<PAGE>   15
                      Information in the possession and the control of the
                      Seller requested by the Buyer; and

            (b)       all original Joint Venture Contracts and Sales Contracts
                      (to the extent that they are in the possession of or
                      under the control of the Seller) or otherwise copies
                      thereof and any other document that evidences the
                      Company's title to Assets.

10.         POST COMPLETION

10.1        EXERCISE OF RIGHTS

            From Completion and until the Shares are registered in the name of
            the Buyer, the Seller agrees, in relation to the Shares, at the
            cost of the Buyer, to act in accordance with the directions of the
            persons appointed under clause 9.4(a).

10.2        CHANGE OF NAME

            The Buyer shall cause the Company to change its name to a name not
            associated with the Seller or any Related Body Corporate of the
            Seller and register the proposed change of name with the
            appropriate regulatory authority for approval within ten (10)
            Business Days of Completion.

10.3        INDEMNITY

            The Buyer indemnifies and holds harmless the Seller from any and
            all liability whatsoever arising out of the implementation of any
            direction given under Clause 10.1.

10.4        POST COMPLETION AUDIT OF OPERATOR'S ACCOUNTS

            (a)    The Buyer acknowledges that for a period of THREE (3) years
                   after the Completion Date the Seller retains its rights to
                   participate in the audits of the Operator's books to be
                   conducted under the terms of the Joint Venture Contracts
                   (subject to any confidentiality restrictions contained in
                   the Joint Venture Contracts and the Buyer agrees to use its
                   reasonable endeavours to enable the Seller to so
                   participate) in respect of the period prior to the Effective
                   Date (and may nominate a representative to attend as a
                   representative of the Buyer at its own cost) and will be
                   entitled to and responsible for any adjustment made to any
                   account maintained under the Joint Venture Contracts arising
                   as a result of any such audit in respect of the period prior
                   to the Effective Date.

            (b)    If as a consequence of such audit, adjustments are made to
                   any of the entries in the Working Capital Statement referred
                   to in Schedule Four, a further adjustment will be paid to
                   the Party entitled within THIRTY (30) Business Days of the
                   results of that audit, provided that no claim can be made
                   under this clause unless the net balance due is greater than
                   TEN THOUSAND DOLLARS ($10,000).





                                      14.

<PAGE>   16
10.5      PRESERVATION OF RECORDS

          (a)    The Buyer must, at its own expense, preserve and keep the
                 records held by it or the Company relating to the business of
                 the Company for a period of SIX (6) years from the Completion
                 Date and shall make such records and personnel available to
                 Seller as may be reasonably required by Seller in connection
                 with, among other things, any insurance claim, legal
                 proceedings, the tax affairs of the Seller or any governmental
                 investigation (including investigation and audits by any
                 taxing authority) relating to the business of the Company
                 prior to the Completion Date.

          (b)    The Buyer consents to the Seller retaining copies of all
                 corporate and Tax records relating to the Company or the
                 Assets provided that the Seller shall not use or disclose them
                 for any purpose other than as contemplated under Clause
                 10.5(a).

11.       TAX REQUIREMENTS

11.1      INFORMATION

          The Seller agrees to make available to the Buyer all information in
          its custody or control relating to the Company or relating to the
          Assets in respect of any period before the Completion Date which the
          Buyer needs to know to enable it to cause the Company to complete any
          Tax return or to make any claim for the undeducted allowable
          expenditure and the undeducted allowable capital expenditure.

11.2      REASONABLE ASSISTANCE

          The Seller agrees to give to the Buyer all reasonable assistance in
          connection with any tax audit of the Company after the Completion
          Date in respect of any period before the Completion Date, provided
          that the Seller's obligation under this clause terminates THREE (3)
          years after the Completion Date.

11.3      BUYER OBLIGATIONS

          The Buyer will not:

          (a)    in relation to any Tax, amend any declaration, election or
                 selection, the giving of a notice or the exercise of an option
                 by the Company in respect of the period ending before the
                 Completion Date without the Seller's prior written consent,
                 which consent shall not be unreasonably withheld;

          (b)    fail to submit any income tax return in relation to the
                 Company for any period which includes the period commencing on
                 the day following the Completion Date and ending at the end of
                 the tax year in which the Completion Date occurs; or





                                      15.

<PAGE>   17
          (c)    amend any income tax return of the Company for any tax year
                 ending at or prior to the end of the tax year in which the
                 Completion Date occurs without the Seller's prior written
                 consent, which consent shall not be unreasonably withheld.

          In this clause, "tax year" means a year ending on 30 June or, where
          the company has a substituted accounting period (within Section 18 of
          the Income Tax Assessment Act 1936, as amended) ending on some date
          other than 30 June, that date.

11.4      SELLER OBLIGATIONS

          The Seller will not submit any income tax return in relation to the
          Company for any period ending before the Completion Date without the
          Buyer's prior written consent, which consent must not be unreasonably
          withheld.

11A.      US TAX PROVISIONS

11A.1     DEFINITIONS:
           
          (a)    UNITED STATES INCOME TAX means any and all Tax arising under
                 or relation to provisions of Subtitles A and F of Title 26 of
                 the Code;

          (b)    OTHER TAXES means any Tax other than United States Income Tax;
                 and

          (c)    CODE means the United States Code (the Internal Revenue Code
                 of 1986, as amended).

11A.2     TAXES

          (a)    The Company is a member of an affiliated group of corporations
                 filing consolidated United States federal income tax returns
                 of which the Seller is the common parent (the U.S. GROUP). The
                 taxable income or loss and any tax credits realised or
                 generated by the Company from July 1, 1997 through to
                 Completion (the SHORT PERIOD) shall be included in the
                 consolidated United States federal income tax return of the
                 U.S. Group.

          (b)    All United States Income Tax returns required to be filed for
                 the Company for all periods prior to and including Completion
                 will be filed in a timely manner (taking into account all
                 extensions of due dates), and each return will be complete and
                 accurate in all material respects. All United States Income
                 Tax imposed upon or payable by the Company for all periods
                 prior to and including Completion will be duly paid by the
                 Seller.

          (c)    Buyer shall bear and pay any sales, use, transfer or other
                 taxes of a similar nature assessed on this Agreement and the
                 transfer of the Shares by Seller to Buyer.





                                      16.

<PAGE>   18
11A.3     SECTION 338

          Neither the Buyer nor the Seller shall make, nor shall either of them
          permit any Related Body Corporate to make, an election under Sec.
          338(a), (g) or (h)(10) of the Code with respect to the sale of the
          Shares of the Company pursuant to this Agreement.

11A.4     SECTION 341(f) CONSENT

          The Company has not filed a consent pursuant to the collapsible
          corporation provisions of Sec. 341(f) of the Code (or any
          corresponding provision of state, local, or foreign income tax law)
          or agreed to have Sec.  341(f)(2) of the Code (or any corresponding
          provision of state, local, or foreign income tax) apply to any
          disposition of any asset owned by it.

11A.5     COOPERATION

          (a)       After the Completion and for as long thereafter as is
                    appropriate, the Buyer shall cause the Company or any such
                    entity to make available to Seller, at the request of
                    Seller and during normal business hours and in a manner
                    which will not unreasonably interfere with its business,
                    the personnel of the Company involved with the preparation
                    and review of the Tax returns and schedules thereto for all
                    taxable periods prior to Completion. Such personnel shall
                    advise or assist with Seller as to the preparation and
                    manner of the inclusion of the items in such returns and
                    schedules and shall provide all other reasonable assistance
                    as Seller shall request relating thereto including, without
                    limitation, furnishing to, or permitting the copying by
                    Seller of any records, returns, schedules, documents,
                    workpapers, or other relevant materials which might
                    reasonably be expected to be of use in connection with any
                    return, examination or proceeding whether ongoing or
                    anticipated.

          (b)       The Buyer and Seller will provide each other with such
                    assistance as may reasonably be requested by either of them
                    in connection with the preparation of any return of Tax,
                    any audit (financial or tax) or other examination by any
                    taxing authority, or any judicial or administrative
                    proceedings relating to liability for Taxes, and each will
                    retain and, upon the request of the other, provide the
                    other with any records or information which may be relevant
                    to such return, audit, examination or proceedings. Such
                    assistance shall include making employees available on a
                    mutually convenient basis to prove additional information
                    and explanation of any material provided hereunder and
                    shall include, without limitation, furnishing to or
                    permitting the copying by the requesting party of any
                    records, returns, schedules, documents, workpapers or other
                    relevant materials which might reasonably be expected to be
                    of use in connection with such return, audit, examination
                    or proceeding. The Party requesting assistance hereunder
                    shall reimburse the Party whose assistance is requested for
                    reasonable out of pocket expenses incurred by it in
                    providing such assistance.





                                      17.

<PAGE>   19
12.       WARRANTIES

12.1      SELLER

          The Seller makes the Warranties in favour of the Buyer as at the
          Effective Date and as at the Completion Date.  The Warranties are
          made subject to the qualifications made in this Agreement and in the
          Schedules and subject to any disclosures made by the Seller in
          writing on or prior to the date of this Agreement.

12.2      BUYER

          The Buyer makes the Warranties in favour of the Seller as at the
          Effective Date and as at the Completion Date.  The Warranties are
          made subject to the qualifications made in this Agreement and in the
          Schedules.

12.3      NO WARRANTY UNLESS EXPRESSLY INCLUDED

          (a)    Save as and only to the extent set forth in Clause 12.1, the
                 Seller makes no representations or warranties in respect of
                 any matter or thing and disclaims all liability and
                 responsibility for any representation, warranty, statement,
                 opinion or information made or communicated (orally or in
                 writing) to the Buyer (including, without limiting the
                 generality of the foregoing, any representation, warranty,
                 statement, opinion, information or advice made and
                 communicated to the Buyer by any officer, stockholder,
                 director, employee, agent, consultant, counsel or adviser of
                 the Seller or a tender document) and the Buyer acknowledges
                 and affirms that it has not relied upon any such
                 representation, warranty, statement, opinion or information in
                 entering into or carrying out the transactions contemplated by
                 this Agreement.

          (b)    Subject to the Warranties, the Buyer acknowledges and affirms
                 that it has made its own independent investigation, analysis
                 and evaluation of the geological, geophysical and engineering
                 interpretations, economic valuations and assessment of tax
                 allowances and prospects for development of the Assets and
                 acknowledges and affirms that in making the decision to
                 purchase the Assets, it has relied to that extent upon its
                 independent investigation and those of its representatives,
                 including professional, legal, tax, economic, financial,
                 business and other advisers.

          (c)    The Buyer acknowledges that subject in all respects to the
                 Warranties:

                 (i)       it has made its own enquiries and has undertaken
                           assessments and due diligence with respect to the
                           Company, the Assets and the business conducted by
                           the Company and has satisfied itself as to the
                           Company's interest in the Titles as set out in
                           Schedule 1 and the Joint Venture Contracts set out
                           in Schedule 5, prior to entering into this
                           Agreement;

                 (ii)      it and its advisers have completed a review of the
                           financial records of the Company for the purpose of
                           verifying the accounts of the Company;





                                      18.

<PAGE>   20
                 (iii)     it has not relied on any representation made by or
                           on behalf of the Seller in making its decision to
                           enter into this Agreement other than the Warranties;

                 (iv)      the Seller gives no representation or warranty in
                           respect of the existence or absence of common law or
                           statutory native title rights in respect of the
                           Assets or whether any claim for native title rights
                           exists or will arise in respect of the Assets and
                           the Buyer acknowledges that it has conducted its own
                           enquiries with respect to native title matters;

                 (v)       the Seller is induced to enter into this Agreement
                           in consequence of these acknowledgments; and

                 (vi)      the Seller gives no representation or warranty as to
                           any Tax balances of the Company, and to the extent
                           Tax balances can be calculated from or derived from
                           the Balance Sheet, any warranty and representation
                           in respect of such balances, their calculation or
                           derivation is denied and the Buyer shall have no
                           claim whatsoever against the Seller in respect
                           thereof.

          (d)    The Buyer agrees that it has actual or constructive knowledge
                 of some of the subject matter of the Warranties and any breach
                 of Warranty will not be enforceable against the Seller to the
                 extent it is shown that the inaccuracy, error or omission
                 underlying the alleged breach was known or was constructively
                 known by the Buyer at or prior to the time the Buyer entered
                 into this Agreement.

          (e)    Without prejudice to the generality of the foregoing, the
                 Seller makes no representations or warranties as to:

                 (i)       the amounts of reserves attributable to and the
                           field life of the Assets;

                 (ii)      any geological, geophysical, engineering, economic
                           or other interpretations, forecasts or evaluations;
                           or

                 (iii)     whether any Tax allowances will in fact be
                           deductible in the hands of the Company.

12.4      REASONABLE ENQUIRY

          Where any Warranty is qualified by any reference to the knowledge or
          awareness or belief of any Party, there shall be implied in that
          warranty or representation a warranty that such Party has made
          reasonable enquiries concerning the subject





                                      19.

<PAGE>   21
          matter of that warranty or representation, save that it shall not be
          deemed to have made enquiries of any third party.

12.5      WARRANTIES - DURATION

          The Warranties shall survive the Completion Date for a period of ONE
          (1) year.

12.6      CONSEQUENTIAL LOSS

          Notwithstanding any other provision of the Agreement, a Party shall
          not under any circumstances be liable to the other under, arising out
          of or in any way connected with this Agreement for any consequential
          loss or damage whether arising in contract or tort (including
          negligence or breach of any statutory duty). For the purposes of this
          clause, consequential loss includes but is not limited to, any
          obligation or inability to produce Petroleum, lost production or loss
          of profits howsoever arising.

12.7      LIMITATION ON CLAIMS

          The Buyer's right to claim for and seek indemnity in respect of any
          claim (whether relating to a breach of the Warranties or otherwise
          relating to the subject matter of this Agreement) is limited as
          follows:

          (a)    the Buyer must give written notice to the Seller of the
                 specific claim in question with reasonable details of the
                 relevant claim, including, if possible, the Buyer's estimate
                 of the amount of the claim, on or before the first anniversary
                 of the Completion Date;

          (b)    the Buyer can only bring a claim for breach of a Warranty or
                 otherwise relating to the subject matter of this Agreement if
                 the amount reasonably claimed exceeds (or where there is more
                 than one claim they exceed the aggregate) ONE HUNDRED THOUSAND
                 DOLLARS ($100,000.00);

          (c)    the maximum aggregate amount which the Buyer may recover from
                 the Seller for breach of the Warranties is the Purchase Price.


12.8      CONDUCT OF CLAIMS

          If the Buyer receives a claim from a third party which may give rise
          to a claim against the Seller under this Agreement, the Buyer must
          within TEN (10) Business Days of receipt, notify the Seller of the
          claim giving full details so far as practicable and, if the Seller
          indemnifies the Buyer and the Company to their reasonable
          satisfaction against all and any costs, charges and expenses which
          may be incurred or for which they may become liable, the Buyer must
          take such action as the Seller reasonably instructs to avoid,
          dispute, resist, appeal, compromise or defend any such claim and any
          adjudication in respect of it.





                                      20.

<PAGE>   22
12.9      BUYER'S REMEDIES

          (a)    Prior to the Completion Date, the Buyer may only rescind this
                 Agreement in accordance with Clause 12.9(b).

          (b)    If not less than THREE (3) Business Days before the Completion
                 Date, the Buyer becomes aware that the Seller is in breach of
                 any of the Warranties of the Seller or any other material
                 provision of this Agreement that has a material adverse effect
                 on the value of the Shares as at the Effective Date, the Buyer
                 shall promptly provide the Seller with written notice
                 containing reasonable details of the said breach in which case
                 the Completion Date shall be automatically extended for a
                 period of TEN (10) Business Days. The Parties will use all
                 reasonable efforts to resolve the matter, failing which the
                 Buyer may not less than THREE (3) Business Days prior to the
                 extended Completion Date, by notice in writing to the Seller:

                 (i)       elect to proceed to Completion on the Completion
                           Date, whereupon no Party shall have any further
                           liabilities or obligations to the other whatsoever
                           in respect of the breach notified; or

                 (ii)      at its option (without prejudice to any other right
                           or other remedy it may have and subject always to
                           Clause 12.7) rescind this Agreement.

12.10     NON-MERGER OF WARRANTIES

          No Warranties merge on Completion.

12.11     RECLAMATION OBLIGATIONS

          All costs, expenses, risks, liabilities and obligations respecting
          the abandonment of any wells which are part of the Assets, closure,
          decommissioning and dismantling the facilities of the Company and any
          reclamation and restoration of all sites shall be borne and paid for
          solely by the Buyer, its successors or assigns, and the Buyer, its
          successors or assigns shall indemnify, defend and save harmless the
          Seller from and against any claims or demands (including breach of
          statutory duty) by any person for or resulting in expense, liability,
          loss, costs, claims or damages direct or indirect (including the
          effects of, and the costs of complying with any order direction, or
          claim of any government or agency having jurisdiction) pertaining to
          the foregoing operations conducted or failed to be conducted by the
          Buyer, its successors or assigns after Completion.
          
12.12     BUYER'S INDEMNITY-ENVIRONMENTAL DAMAGE
          
          (a)       The Buyer, its successors or assigns, shall, after
                    Completion, be liable to the Seller for all loss, costs,
                    damages or expenses which the Seller may suffer and, in
                    addition, shall indemnify, defend and save harmless the
                    Seller from and against any claims or demands (including
                    breach of statutory duty) or damages, direct or indirect,
                    before, on and after Completion (including the
          




                                      21.

<PAGE>   23
                           effects of, and the costs of complying with, any
                           order, direction, or claim of any government or
                           agency having jurisdiction) arising out of or
                           resulting from Environmental Damage caused or
                           alleged to have been caused in respect of the
                           Assets.

                 (b)       For the purpose of this clause:


                           ENVIRONMENTAL DAMAGE means any one or more of:


                           (i)   ground water, surface water or aquifer
                                 contamination;

                           (ii)  soil contamination;

                           (iii) corrosion or deterioration of structures,
                                 equipment, fences and other property;

                           (iv)  toxic or hazardous substance releases or
                                 emissions;

                           (v)   death or injury to human beings caused in
                                 whole or in part by any of items (i) through 
                                 (iv) above;

                           (vi)  death or injury to plants and animals caused
                                 in whole or in part by any of items (i) through
                                 (iv) above; and

                           (vii) natural resource damages.

13.       TERMINATION AND DAMAGES

13.1      RIGHT TO TERMINATE

          If not less than THREE (3) Business Days before the Completion Date,
          the Buyer is in breach of any of the Warranties of the Buyer or any
          other material provision of this Agreement such that the interest of
          the Seller under this Agreement is materially adversely affected,
          then the Seller shall promptly provide the Buyer with written notice
          containing reasonable details of the said breach in which case the
          Completion Date shall be automatically extended for a period of TEN
          (10) Business Days. The Parties will use all reasonable endeavours to
          resolve the matter, failing which the Seller may not less than THREE
          (3) Business Days prior to the extended Completion Date, by notice in
          writing to the Buyer elect to:

          (a)    complete this Agreement on the extended Completion Date,
                 whereupon no Party shall have any further liabilities or
                 obligations to the other whatsoever in respect of the breach
                 notified; or

          (b)    terminate its obligations under this Agreement, without
                 prejudice to any right or other remedy it may have against the
                 Buyer.





                                      22.

<PAGE>   24
13.2      REMEDY

          The Seller may not give a notice under Clause 13.1(a) or (b) to the
          Buyer where the breach is capable of remedy and has been remedied by
          not less than THREE (3) Business Days before the extended Completion
          Date.

13.3      OTHER TERMINATION RIGHTS

          Either the Buyer or the Seller may terminate this Agreement by
          written notice to the other of them where:

          (a)    the other of them convenes a meeting of its creditors or
                 proposes or enters into a scheme of arrangement or composition
                 with its creditors;

          (b)    there is a liquidation of the other of them;

          (c)    a receiver or receiver and manager is appointed to the other
                 of them;

          (d)    a person holding a security interest over the assets of the
                 other of them takes or attempts to take possession of those
                 assets;

          (e)    an administrator is appointed to the other of them under Part
                 5.3A of the Corporations Law; or

          (f)    the other Party repudiates its obligations under this
                 Agreement.

14.       COSTS, EXPENSES AND DELAYED PAYMENT

14.1      STAMP DUTY

          (a)    The Buyer must pay any stamp duty in respect of the execution,
                 delivery and performance of this Agreement and any agreement
                 or document entered into or signed in contemplation of this
                 Agreement.

          (b)    The Buyer must pay any fine, penalty or other cost in respect
                 of a failure to pay any stamp duty for which it is responsible
                 under Clause 14.1(a), except to the extent that the fine,
                 penalty or other cost is caused by an act or default on the
                 part of the Seller.

          (c)    The Buyer must within FIFTEEN (15) Business Days of the date
                 of this Agreement submit this Agreement for an assessment of
                 stamp duty and use its reasonable endeavours to secure and pay
                 an assessment in respect of this Agreement as soon as
                 practicable and will keep the Seller appraised of progress.
                 The Seller agrees to assist the Buyer when requested and, in
                 particular, to respond to requisitions (if any) for further
                 information.

14.2      COSTS AND EXPENSES

          Subject to Clause 14.1, each Party must pay its own costs and
          expenses in respect





                                      23.

<PAGE>   25
          of the negotiation, preparation, execution, delivery and registration
          of this Agreement or other Agreement or document entered into or
          signed in connection with the subject matter of this Agreement.

14.3      LATE INTEREST

          Without prejudice to any other rights under this Agreement, if any
          amount payable under this Agreement is not paid when due, the
          defaulting Party shall pay interest on a daily basis on such amount
          from the due date of payment (after as well as before judgment) at a
          rate equal to SIX PER CENT (6%) over the Agreed Rate.

15.       CONFIDENTIALITY AND ANNOUNCEMENTS

15.1      AGREED ANNOUNCEMENTS

          No Party shall, without the written consent of the other Party (which
          consent shall not be unreasonably withheld), issue or make any public
          announcement relating to, or disclose anything regarding, this
          Agreement.

15.2      LEGAL REQUIREMENTS

          (a)    If a Party is required to disclose anything in respect of this
                 Agreement in order to comply with:

                 (i)       applicable law; or

                 (ii)      the requirements of any recognised stock exchange on
                           which a Parties' or its Related Body Corporates'
                           shares are listed;

                 then the Parties shall agree on the form and substance of such
                 disclosure and a copy of the same shall be furnished to the
                 other Parties prior to publication or release.

          (b)    A Party will be deemed to have agreed to the terms of any
                 disclosure if it has not objected to the form or substance of
                 such release within ONE (1) Business Day of it being received
                 by the Party. Each Party agrees to use its best endeavours to
                 approve releases as soon as possible so that Parties are able
                 to comply with statutory or stock exchange requirements.

16.       ASSIGNMENT

          Neither Party may assign the rights under, or the benefit or the
          burden of, this Agreement.

17.       NOTICE

          A notice, demand, consent or authority given or made to a person:

          (a)    must be in writing;





                                      24.

<PAGE>   26
          (b)    may be given or made by:

                 (i)       delivering it to that person personally;

                 (ii)      addressing it to that person and either leaving it
                           at, or posting it to, the address of that person
                           appearing in this Agreement or any other address
                           nominated by that person by notice to the person
                           giving the notice; or

                 (iii)     sending a facsimile copy of the notice to the
                           facsimile copier number nominated by that person by
                           notice to the person giving the notice; and

          (c)    will be deemed to be given or made:

                 (i)       if by leaving it at the address of that person, when
                           left at that address;

                 (ii)      if by post, on the second Business Day after the
                           date of posting (if posted to an address in the same
                           country) or on the seventh Business Day after the
                           date of posting (if posted to an address in another
                           country);

                 (iii)     if by facsimile, on receipt by the sender of a
                           transmission control report from the despatching
                           machine showing the relevant number of pages and the
                           correct destination facsimile machine number and
                           indicating that the transmission had been made
                           without error,

                 but if the result is that a notice would be taken to be given
                 or made on a day which is not a Business Day in the place to
                 which the notice is sent or is later than 4.00pm (local time)
                 it will be taken to have been duly given or made at the
                 commencement of business on the next Business Day in that
                 place.

18.       PROPER LAW

          This Agreement is governed by, and to be interpreted in accordance
          with, the laws of Western Australia and where applicable the laws of
          the Commonwealth of Australia.

19.       JURISDICTION

          The Parties agree to submit to the jurisdiction of the courts of
          Western Australia and if applicable the Commonwealth of Australia.

20.       COUNTERPARTS

          This Agreement may be executed in any number of counterparts each of
          which is





                                      25.

<PAGE>   27
          an original instrument and all of which constitute one and the same
          instrument.

21.       ENTIRE AGREEMENT

21.1      AGREEMENT CONSTITUTES ENTIRE AGREEMENT

          This Agreement constitutes the entire agreement between the Parties
          with respect to the subject matter of this Agreement and contains all
          of the representations, warranties, covenants and agreements of the
          Parties and supersedes all prior agreements and understandings in
          relation to the subject matter of the Agreement as at the date of
          this Agreement, other than the confidentiality agreement entered into
          by the Parties prior to execution of this Agreement which remains in
          force until Completion.

21.2      NO RELIANCE ON ORAL REPRESENTATIONS

          Each Party acknowledges that it has not relied on any oral statement,
          representation, undertaking, covenant or agreement made before the
          date of this Agreement relating to the subject matter of this
          Agreement and not contained in this Agreement.

22.       MORATORIUM NOT TO APPLY

          To the fullest extent permitted by law, the provisions of a statute
          which would, but for this clause:

          (a)    extend or postpone the date of payment of money; or

          (b)    abrogate, nullify, postpone or otherwise affect any condition;

          under this Agreement do not apply to limit or affect the terms of
          this Agreement.

23.       SEVERANCE

          (a)    If any part of this Agreement is, or becomes, void or
                 unenforceable, that part is, or will be, severed from this
                 Agreement so that all parts that are not, or do not become,
                 void or unenforceable remain in full force and effect and are
                 unaffected by that severance.

          (b)    If any provision of this Agreement, or the application thereof
                 to any person or any circumstance, is invalid or
                 unenforceable, a suitable and equitable provision shall be
                 substituted therefor in order to carry out, so far as may be
                 valid and enforceable, the intent and purpose of such invalid
                 or unenforceable provision and the remainder of this Agreement
                 and the application of such provision to other persons or
                 circumstances shall not be affected by such invalidity or
                 unenforceability, nor shall such invalidity or
                 unenforceability affect the validity or enforceability of such
                 provision, or the application thereof, in any other
                 jurisdiction.





                                      26.

<PAGE>   28
24.       WAIVERS

24.1      FAILURE OR DELAY IS NOT WAIVER

          Failure to exercise or delay in exercising any right, power or
          privilege by a Party does not operate as a waiver of that right,
          power or privilege.

24.2      PARTIAL EXERCISE DOES NOT PRECLUDE FURTHER EXERCISE

          A single or partial exercise of any right, power or privilege by a
          Party does not preclude:

          (a)    any other or further exercise of that right, power or
                 privilege; or

          (b)    the exercise of any other right, power or privilege.

25.       VARIATION

          This Agreement may be varied only by agreement in writing signed by
          the Parties.
        
26.       FURTHER ASSURANCES

          Each Party must execute and do all acts and things necessary or
          desirable to implement and give full effect to the provisions and
          purpose of this Agreement.

27.       MERGER

          The rights and obligations of the Parties will not merge on the
          completion of any transaction contemplated by this Agreement. They
          will survive the execution and delivery of any assignment or other
          document entered into for the purpose of implementing any such
          transaction.

28.       INTERPRETATION

28.1      REFERENCE TO A STATUTE

          A reference to a statute includes a regulation, by-law, requisition
          and order made under that statute and any amendment to or
          re-enactment of that statute, regulation, by-law, requisition or
          order for the time being in force.

28.2      JOINT AND SEVERAL COVENANTS

          If the Buyer comprises two or more persons, the covenants and
          agreements on their part bind and must be observed and performed by
          them jointly and each of them severally and may be enforced against
          any one or any two or more of them.

28.3      LAST DAY NOT A BUSINESS DAY

          When the day or last day for doing an act is not a Business Day in
          the place where





                                      27.

<PAGE>   29
          that act is to be done, the day or last day for doing the act will be
          the next following Business Day in the place where that act is to be
          done.

28.4      HEADINGS

          Except in the Schedule, headings in this Agreement are for
          convenience and identification of clauses only and do not otherwise
          affect its interpretation.

28.5      REFERENCE TO OTHER DOCUMENT

          Subject to any contrary provision in this Agreement, a reference to
          any other deed, agreement, instrument or contract (including the
          Joint Venture Contracts and the Sales Contracts) includes a reference
          to that other deed, agreement, instrument or contract as amended,
          supplemented or varied from time to time.

28.6      REFERENCE TO A PARTY

          Unless contrary to the sense or context, a reference to a Party
          includes that Party's administrators, personal representatives,
          successors and assigns, and if the Buyer comprises two or more
          persons, administrators, personal representatives, successors and
          assigns of each of those persons.

28.7      SINGULAR, PLURAL AND GENDER

          Where applicable:

          (a)    words denoting the singular include the plural;

          (b)    words denoting the plural include the singular; and

          (c)    words denoting a gender include each gender.

28.8      REFERENCE TO A PERSON AND A BODY CORPORATE

          Where applicable:

          (a)    a reference to a body corporate includes a natural person; and

          (b)    a reference to a person includes a body corporate.

28.9      PROFESSIONAL BODY

          A reference to a professional body includes a successor to or
          substitute for that body.

28.10     PARTIES IN INTEREST

          This Agreement shall inure to the benefit of and be binding upon the
          Parties and their respective successors and permitted assigns.
          Nothing in this Agreement,





                                      28.

<PAGE>   30
          express or implied, is intended to confer upon any person other than
          the Buyer, the Seller or their respective successors or permitted
          assigns, any rights or remedies under or by reason of this Agreement.



EXECUTED BY THE PARTIES

                                 
THE COMMON SEAL of AMPOLEX          )
(PNG HOLDINGS) INC is affixed in    )                     [SEAL]
accordance with its articles of     )
association in the presence of:     )
                                 
/s/ Dan P. Haworth                      /s/ Graeme K. Alexander              
- ------------------------------------    ----------------------------------------
Signature Director                      Signature Secretary*
                                 
Dan P. Haworth                          Graeme K. Alexander                 
- ------------------------------------    ----------------------------------------
Print full name of signatory            Print full name of signatory
                                   
*  Delete if not applicable        


SIGNED for and on behalf of         )
APACHE CORPORATION by               )
LISA A FLOYD as duly authorised     )   /s/ Lisa A. Floyd     
                                        ----------------------------------------
corporate representative            )   Lisa A Floyd
in the presence of:                 )
                                    
                                    
/s/ Eve A. Howell                   
- -----------------------------------
Witness                             
                                    


                                      29.

<PAGE>   31
                                  SCHEDULE ONE

1.        TITLES

          Exploration Permit WA-192-P
          Exploration Permit EP 307
          Exploration Permit EP 358
          Exploration Permit TP/8
          Production Licence TL/1
          Production Licence TL/5
          Production Licence TL/6
          Pipeline Licence PL/12
          Pipeline Licence PL/17
          Pipeline Licence TPL/1
          Pipeline Licence TPL/2
          Pipeline Licence TPL/5
          Pipeline Licence TPL/8

2.        INTERESTS

          24% interest in the Assets.

3.        SPECIFIED ENCUMBRANCES

          1.     Charge No. 225400 registered on 19/01/1990 given by the
                 Company pursuant to Section 16.3 of the Joint Operating
                 Agreement for Exploration and Appraisal of WA-192-P and EP 307
                 dated 5 August 1985;

          2.     Charge No. 225386 registered on 19/01/1990 given by the
                 Company pursuant to Section 16.3 of the Joint Operating
                 Agreement for Exploration and Appraisal of Production Licences
                 dated 5 August 1985;

          3.     Charge No. 225411 registered on 19/01/1990 given by the
                 Company pursuant to Section 12.4 of an Approved Field Joint
                 Operating Agreement (WA-192-P Development and Production)
                 dated 5 August 1985.





                                      30.

<PAGE>   32
                                  SCHEDULE TWO
                              SELLER'S WARRANTIES


1.        SHARES

1.1       The Seller is the registered holder and beneficial owner of the
          Shares and has power to transfer title to the Shares being the only
          shares issued in the capital of the Company.

1.2       The Shares have been validly issued and are free from all
          Encumbrances.

1.3       There are no restrictions known to the Seller on the transfer of the
          Shares, save that the approval of the board of directors of the
          Company may be required in order to register the transfers.

1.4       The Company has not granted to any person a right to subscribe for or
          acquire or convert any security into any of the Company's unissued
          shares.

1.5       No person has any pre-emptive right with respect to any of the
          Shares.

1.6       The Company is not under an obligation to issue further shares.

1.7       There are no dividends declared by the Company which are not paid or
          credited to a loan account of a shareholder of the Company.

2.        STATUS OF THE COMPANY

2.1       The copy of the By Laws of the Company initialled for identification
          by an officer of the Company and produced prior to executing this
          Agreement is a true copy and includes all amendments made up to the
          date of this Agreement.

2.2       No resolution to alter the Company's By Laws has been passed since
          the Effective Date.

2.3       The Company is not:

          (a)    wound up, no resolution for its winding up has been passed and
                 no meeting of members or creditors has been convened for that
                 purpose;

          (b)    the subject of a winding up application which has been made to
                 a Court, and no event has occurred which would entitle any
                 person to apply to a Court to wind up the Company;

          (c)    a party to a composition or arrangement with any of its
                 creditors;

          (d)    the recipient of a statutory demand;





                                      31.

<PAGE>   33
          (e)    in receivership and none of its assets is in the possession of
                 or under the control of a mortgagee or chargee; or

          (f)    subject to administration,

          and the Seller is not aware of any facts or circumstances which
          would, or are likely to, result in any of the above.

2.4       The Company has not received any notice or warning of possible
          cancellation of registration of the Company.

3.        BALANCE SHEET

          The Balance Sheet, to the best of the knowledge of the Seller and
          subject to the notes to the accounts and other matters noted:

          (a)    presents a true and fair view of the financial position of the
                 Company as at the Effective Date; and

          (b)    has been prepared and audited in accordance with the relevant
                 accounting standards and generally accepted accounting
                 principles consistently applied.

4.        TITLE TO ASSETS

          The Company has good title to the Assets.

5.        POWER OF ATTORNEY

          The Company has not granted any power of attorney which will be
          effective at or after Completion.

6.        PROCEEDINGS PENDING

6.1       The Company is not engaged in any litigation, arbitration,
          prosecution or other legal proceedings, or any proceedings or
          hearings before any statutory or governmental body, department, board
          or agency.

6.2       To the Seller's best knowledge and belief there are no facts which
          are likely to give rise to any litigation, arbitration, prosecution
          or other legal proceedings, or any proceedings or hearings before any
          statutory or governmental body, department, board or agency.

7.        BUSINESS SINCE EFFECTIVE DATE

          Since the Effective Date:





                                      32.

<PAGE>   34
          (a)    the Company has carried on business and dealt with its
                 property and assets only as a consequence of trading in the
                 ordinary course of business, save as disclosed by the Seller;

          (b)    no alteration has been made to the share capital of the
                 Company;

          (c)    the Company has not declared or paid any dividend or any
                 amount which may be deemed to be a dividend or passed any
                 special resolution;

          (d)    the Company has not granted any Encumbrance over or any part
                 of the Assets other than under the Joint Venture Contracts and
                 the Specified Encumbrances; and

          (e)    the Company has no employees.

8.        CONTRACTS

8.1       To the best of the Seller's knowledge, all agreements binding on the
          Company not entered into in the ordinary course of Business of the
          Company have been disclosed to the Buyer.

8.2       To the best of the Seller's knowledge, the Company is not party to
          any agreement which may be terminated by any other party by reason of
          a change in the ownership of the Shares by reason of the change being
          subject to the consent of the other party, which consent has not been
          obtained.

8.3       All material agreements entered into by the Company have been
          executed in accordance with the Company's Articles of Association,
          are within the authority of the Company and are valid and binding on
          the Company and, to the best of the Seller's knowledge and belief, on
          the other parties to those agreements.

9.        SUBSIDIARIES

          The Company has no subsidiaries at the Completion Date.

10.       AUTHORITY

10.1      The Seller is duly incorporated with limited liability and validly
          existing under the laws of its country of incorporation.

10.2      The documents which contain or establish the Sellers' constitution
          incorporate provisions which authorise, and all necessary corporate
          action has been taken to authorise, the Seller to execute and deliver
          this Agreement and this Agreement does, and the further documents to
          be executed by the Seller hereunder will, constitute legal, valid and
          binding obligations of the Seller enforceable against them in
          accordance with their respective terms.





                                      33.

<PAGE>   35
10.3      The signing and delivery of this Agreement and the performance of the
          transaction contemplated by this Agreement will not contravene or
          constitute a default under a provision contained in any agreement,
          instrument, law, judgment, order, licence, permit or consent by which
          the Seller is bound.

10.4      The Seller has not incurred any obligation or liability, contingent
          or otherwise, for brokers' or finders' fees in respect of the
          transaction under this Agreement for which the Buyer will have any
          obligation.

11.       COMPLETENESS OF INFORMATION

          The Seller has provided to the Buyer all information within its
          knowledge which could reasonably be considered to be material in
          relation to the Company, the Shares and the Assets or to their value.

12.       ASSETS

12.1      The Company's legal and beneficial ownership of the Assets is as set
          out in Schedule One, free and clear of all Encumbrances, other than
          as there set out or in the Joint Venture Contracts, Specified
          Encumbrances, the terms of grant of the Titles or under the Petroleum
          Legislation.

12.2      The Joint Venture Contracts are to the best of the knowledge and
          belief of the Seller, a complete list of all material agreements
          constituting or regulating the interests of the Seller in the Titles.

12.3      The Seller has not received any notice of any material breach of its
          obligations under the Joint Venture Contracts or the Sale Contracts.

12.4      The Seller is not in material default under the Joint Venture
          Contracts or the Sale Contracts.

13.       OPERATIONS

          To the best of the knowledge and belief of the Seller:

          (a)    all material conditions and obligations to which the Assets
                 are subject have been complied with and performed; and

          (b)    all Petroleum operations with respect to the Assets have been
                 and are now conducted in accordance with applicable laws and
                 good oilfield practice.

14.       DEFAULT OF OTHER VENTURERS

          The Company has not in the last TWELVE (12) months received any
          notice of default in respect of any other party to the Joint Venture
          Contracts.





                                      34.

<PAGE>   36
15.       COMPLIANCE

          Except in relation to Tax matters:

          (a)    to the best knowledge and belief of the Seller there are no
                 material notices of any public or statutory authority
                 outstanding against the Company; and.

          (b)    the Company has complied in all material respects with the
                 provisions of all laws and regulations and all orders, notices,
                 awards and determinations made by any statutory or other 
                 competent authority in any way relating to or binding on the 
                 Company or the Assets.





                                      35.

<PAGE>   37
                                 SCHEDULE THREE
                               BUYER'S WARRANTIES

          WARRANTIES OF THE BUYER

          (a)    The Buyer is duly incorporated with limited liability and
                 validly existing under the laws of its country of
                 incorporation.

          (b)    The signing and delivery of this Agreement and the performance
                 of the transactions contemplated by this Agreement will not
                 contravene or constitute a default under the provision
                 contained in any agreement, instrument, law, judgment, order,
                 license, permit or consent by which the Buyer is bound.

          (c)    The Buyer has not incurred any obligation or liability,
                 contingent or otherwise, for brokers' or finders' fees in
                 respect of the transaction herein provided for which the
                 Sellers will have any obligation.

          (d)    The Shares are being purchased by the Buyer for its own
                 account for investment and not for the purpose of, or with a
                 view to, the resale or distribution thereof. The Buyer
                 acknowledges that the sale or resale of the Shares under this
                 Agreement has not been registered under the U.S. Securities
                 Act 1933, as amended, and that no further sales of the Shares
                 can be made unless registration or exemption from registration
                 under such Act is available.

          (e)    The documents which contain or establish the Buyer's
                 constitution incorporate provisions which authorise, and all
                 necessary corporate action has been taken to authorise, the
                 Buyer to execute and deliver this Agreement and this Agreement
                 does, and the further documents to be executed by the Buyer
                 hereunder will, constitute legal, valid and binding
                 obligations of the Buyer enforceable against them in
                 accordance with their respective terms.

          (f)    The signing and delivery of this Agreement and the performance
                 of the transaction contemplated by this Agreement will not
                 contravene or constitute a default under a provision contained
                 in any agreement, instrument, law, judgment, order, licence,
                 permit or consent by which the Buyer is bound.

          (g)    The Buyer, on the Completion Date, will have sufficient funds
                 to effect Completion and all other transactions contemplated
                 by this Agreement.

          (h)    Except as specifically set forth in this Agreement, no
                 consent, approval, waiver or authorisation is required to be
                 obtained by the Buyer and no notice or filing is required to
                 be given by the Buyer with any federal, state, local or other
                 governmental authority in connection with the execution,
                 delivery and performance by the Buyer of this Agreement.

          (i)    The Buyer is not:





                                      36.

<PAGE>   38
                 (i)       wound up, no resolution for its winding up has been
                           passed and no meeting of members or creditors has
                           been convened for that purpose;

                 (ii)      the subject of a winding up application which has
                           been made to a Court, and no event has occurred
                           which would entitle any person to apply to a Court
                           to wind up the Buyer;

                 (iii)     a party to a composition or arrangement with any of
                           its creditors;

                 (iv)      the recipient of a statutory demand under sections
                           459A-461 of the Corporations Law or any equivalent
                           or analagous legislation in any jurisdiction
                           relevant to the Buyer;

                 (v)       in receivership and none of its assets is in the
                           possession of or under the control of a mortgagee or
                           chargee; or

                 (vi)      subject to administration under Part 5.3A of the
                           Corporations Law or any equivalent or analagous
                           legislation in any jurisdiction relevant to the
                           Buyer.

          (j)    The Buyer has not received from any relevant authority any
                 notice or warning of possible cancellation of registration of
                 the Company.

          (k)    The Buyer is not engaged in any litigation, arbitration,
                 prosecution or other legal proceedings, or any proceedings or
                 hearings before any statutory or governmental body,
                 department, board or agency which would be likely to prejudice
                 the Buyer's performance of its obligations under this
                 Agreement.

          (l)    There are no facts known to the Buyer which are likely to give
                 rise to any litigation, arbitration, prosecution or other
                 legal proceedings, or any proceedings or hearings before any
                 statutory or governmental body, department, board or agency
                 involving the Buyer which would be likely to prejudice the
                 Buyer's performance of its obligations under this Agreement.





                                      37.

<PAGE>   39
                                 SCHEDULE FOUR
                                   ACCOUNTS

1.        PREPARATION

          (a)    The initial working capital statement at 30 June 1997 which is
                 based on the Balance Sheet is attached as Schedule Eight.


          (b)    The Seller shall procure that the Company prepares a statement
                 of Working Capital of the Company taking into account the
                 adjustments under Part 2 of this Schedule (WORKING CAPITAL
                 STATEMENT) not less than SEVEN (7) days prior to the
                 Completion Date;

          (c)    The Seller shall prepare the following statements of account:

                 (i)       a profit and loss account in respect of the Assets
                           for the period from the Effective Date to the end of
                           the month immediately prior to the Completion Date
                           (ADJUSTMENT DATE) (PROFIT AND LOSS ACCOUNT); and

                 (ii)      a statement of capital expenditure in respect of the
                           Assets from the Effective Date to the Adjustment
                           Date (CAPITAL STATEMENT).

          (d)    All amounts in US dollars are to be converted to Australian
                 dollars based on the transaction settlement date converted at
                 the Wholesale Market Hedge rate published in the Australian
                 Financial Review.

          (e)    The Working Capital Statement, the Profit & Loss Account and
                 the Capital Statement are referred to as the ACCOUNTS.

2.        WORKING CAPITAL

          (a)    The working capital figure in the Working Capital Statement
                 will take into account the matters set out in this Part in
                 respect of the Assets, the Joint Venture Documents and the
                 hydrocarbons produced from the Assets.

          (b)    For the purpose of the Working Capital Statement, the working
                 capital figure will be based on, but not limited to, the
                 initial items taken from the  initial Working Capital
                 Statement in Schedule Eight, but will be varied, to the extent
                 that any variation is necessary, to take into account:

                 (i)       the purchase price of the hydrocarbons on hand as at
                           00:01 on the Effective Date determined in accordance
                           with paragraphs (c) and (d) (such amounts to be
                           treated as a current asset);





                                      38.

<PAGE>   40
                 (ii)      the amount of any calls payable in respect of the
                           Assets after 00:01 on the Effective Date, which were
                           paid on or before the Effective Date (such amounts
                           to be treated as a current asset);

                 (iii)     the amount of any calls payable in respect of the
                           Assets on or before 00:01 on the Effective Date,
                           which were unpaid on or before the Effective Date
                           (such amounts to be treated as a current liability);

                 (iv)      any other outstanding amount by or to the Company in
                           respect of the Assets that relate to operations of
                           the Company on or before the Effective Date; and

                 (v)       any over contribution or under contribution in
                           respect of the Company recorded in the books of the
                           Operator at the Effective Date.

          (c)    The Company's interest in the stock of hydrocarbons
                 attributable to the Assets on hand as at 00:01 on the
                 Effective Date comprises:

                 (i)       liquids downstream of the wellheads as estimated by
                           the Operator; and

                 (ii)      gas downsteam of the low temperature separation
                           plant as estimated by the Operator.

          (d)    The purchase price of the hydrocarbons on hand will be:

                 (i)       for all of such hydrocarbons, the actual proceeds of
                           sale; less

                 (ii)      for all of such hydrocarbons, actual or (where no
                           actual is available) estimated transportation,
                           wharfage and royalty costs incurred through to the
                           point of sale, where estimates are based on the
                           average per barrel implied from actual payments over
                           the preceding three months.

3.        PROFIT & LOSS ACCOUNT

          (a)    The Profit and Loss Account shall take into account:

                 (i)       the amount of operating costs included in any calls
                           paid in respect of the Assets from the Effective
                           Date to the Adjustment Date and the costs of
                           insurances under Clause 8.3 (such amounts to be
                           treated as expenses); and

                 (ii)      the amount of any cash received or entitled to be
                           received in respect of sales of hydrocarbons made
                           pursuant to the Sales Contracts and invoiced in the
                           period from the Effective Date to the Adjustment





                                      39.

<PAGE>   41
                           Date and any other income otherwise received in
                           respect of the Assets (such amounts to be treated as
                           revenue).

          (b)    In this Part, if the total of revenue exceeds the total of
                 expenses, then the amount of the difference shall be charged
                 to the Seller Account, otherwise the amount of the difference
                 shall be charged to the Buyer Account.

          (c)    The United States income tax payable with respect to the
                 Interim Period profits of the Company shall be charged to the
                 Buyer Account.

4.        CAPITAL STATEMENT

          (a)    The Capital Statement shall take into account the amount of
                 any capital cost or receipt comprised or adjusted for in any
                 call paid or received in respect of the Assets from the
                 Effective Date to the Adjustment Date (such amounts to be
                 treated as property, plant and equipment).

          (b)    In this Part, if the total of capital costs under paragraph
                 (a) exceeds the total of capital receipts, then the amount of
                 the difference shall be charged to the Buyer Account,
                 otherwise the amount of the difference shall be charged to the
                 Seller Account.

5.        PROCEDURE TO AGREE ACCOUNTS

          (a)    Not less than SEVEN (7) Business Days prior to the projected
                 Completion Date, the Seller agrees to submit the Accounts to
                 the Buyer. The Seller will provide supporting documentation.

          (b)    Within FOUR (4) Business Days of the date on which the Seller
                 provides the Accounts (or such shorter time as the parties
                 agree), the Buyer agrees to advise the Seller in writing as to
                 any amounts it does not agree to, including its reasons.

          (c)    The Parties will in good faith seek to reach agreement without
                 delay on any amounts not agreed to between them.

          (d)    If no notice is given by the Buyer under paragraph (b) of this
                 Part, then the Accounts will be treated as the Accounts for
                 the purposes of determining the amounts to be paid or allowed
                 at Completion.

          (e)    If a notice is given by any Party under paragraph (b) of this
                 Part and the Parties do not resolve the matter within THREE
                 (3) Business Days prior to Completion, then the Parties will
                 pay at Completion the amounts in the Buyer Account and the
                 Seller Account not in dispute under clause 4 of the Agreement.

          (f)    If any amount is not agreed nor paid or allowed at Completion,
                 then either Party may give notice to the other that the matter
                 be referred to an





                                      40.

<PAGE>   42
                 Independent Accountant. The notice must suggest a person to be
                 the Independent Accountant and process set out in Schedule 6
                 must be followed.

          (g)    If a reference is made to the Independent Accountant under
                 paragraph (f) of this Part, the terms of reference must be to
                 resolve the matters in dispute in accordance with the
                 principles set out in Parts 1, 2, 3 and 4 of this Schedule as
                 soon as possible. The Buyer and Seller must co-operate and
                 make information available as requested by the Independent
                 Accountant. The Buyer and the Seller must ensure that the
                 Company promptly makes available such information as the
                 Independent Accountant may request in relation to the matters
                 in dispute. All correspondence between the Independent
                 Accountant and any Party must be promptly copied to the other
                 Party.

          (h)    The Independent Accountant must issue a certificate as to his
                 determination of the matters referred to him and of the
                 Accounts, adjusted (if necessary) to take account of his
                 determinations. The Buyer and Seller agree that in carrying
                 out this role, the Independent Accountant acts as expert and
                 not arbitrator and that, in the absence of fraud or mistake or
                 manifest error, the certificate issues by the Independent
                 Accountant will be final and binding on them.

          (i)    The Buyer and the Seller will bear equally the costs of the
                 Independent Accountant.

6.        POST COMPLETION ADJUSTMENTS FOR PERIOD BETWEEN ADJUSTMENT DATE AND
          COMPLETION

          (a)    Within THIRTY (30) days after the end of the month in which
                 Completion occurs the Seller will prepare the Accounts and
                 submit them to the Buyer, in each case made up to the
                 Completion Date.

          (b)    The Parties will follow the procedures set out in Part 5 of
                 this Schedule to determine the Buyer Account and the Seller
                 Account as at the Completion Date.

          (c)    Any difference between the Buyer Account and the Seller
                 Account at the Adjustment Date and at the Completion Date will
                 be paid to the Party entitled by the other Party within FIVE
                 (5) Business Days of determination of those Accounts.





                                      41.

<PAGE>   43
                                 SCHEDULE FIVE

JOINT VENTURE CONTRACTS

Approved Field Joint Operating Agreement (WA-192-P Development and Production)
("Production JOA") dated 5 August 1985 between Bond Corporation Pty Ltd, Texas
Eastern Australia, Inc., Reading & Bates Australia Petroleum Co., Petro Energy
Limited, Pontoon Oil & Minerals NL, Pelsart Oil NL, Swan Television & Radio
Broadcasters Limited and New World Oil & Developments Pty Ltd;

Joint Operating Agreement for Exploration and Appraisal of WA-192-P and EP307
("Permit Exploration JOA") dated 5 August 1985 between Bond Corporation Pty
Ltd, Texas Eastern Australia, Inc., Reading & Bates Australia Petroleum Co.,
Petro Energy Limited, Pontoon Oil & Minerals NL, Pelsart Oil NL, Swan
Television & Radio Broadcasters Limited and New World Oil & Developments Pty
Ltd;

Joint Operating Agreement for Exploration and Appraisal of Production Licence
("Production Licence Exploration JOA") dated 5 August 1985 between Bond
Corporation Pty Ltd, Texas Eastern Australia, Inc., Reading & Bates Australia
Petroleum Co., Petro Energy Limited, Pontoon Oil & Minerals NL, Pelsart Oil NL,
Swan Television & Radio Broadcasters Limited and New World Oil & Developments
Pty Ltd;

Production - Exploration Co-Ordination Deed (WA-192-P and Production Licence)
dated 5 August 1985 between Bond Corporation Pty Ltd, Texas Eastern Australia,
Inc., Reading & Bates Australia Petroleum Co., Petro Energy Limited, Pontoon
Oil & Minerals NL, Pelsart Oil NL, Swan Television & Radio Broadcasters Limited
and New World Oil & Developments Pty Ltd;

Seller's Representative Agreement WA-192-P New Production Licence - Produced
Petroleum dated 5 August 1985 between Bond Corporation Pty Ltd, Texas Eastern
Australia, Inc., Reading & Bates Australia Petroleum Co., Petro Energy Limited,
Pontoon Oil & Minerals NL, Pelsart Oil NL, Swan Television & Radio Broadcasters
Limited and New World Oil & Developments Pty Ltd;

Deed of Cross Charge given by the Company (No. 225400) pursuant to Permit
Exploration JOA created 18 January 1990 and other charges given by New World
Oil & Developments Pty Ltd, Ampolex Varanus Pty Ltd, Apache Northwest Pty Ltd,
Hardy Petroleum Limited, Novus UK (Harriet) Limited, Tap (Harriet) Pty Ltd and
Kufpec Australia Pty Ltd in favour of the Company pursuant to that JOA;

Deed of Cross Charge given by the Company (No. 225386) pursuant to Production
Licence Exploration JOA created 18 January 1990 and other charges given by New
World Oil & Developments Pty Ltd, Ampolex Varanus Pty Ltd, Apache Northwest Pty
Ltd, Hardy Petroleum Limited, Novus UK (Harriet) Limited, Tap (Harriet) Pty Ltd
and Kufpec Australia Pty Ltd in favour of the Company pursuant to that JOA;





                                      42.

<PAGE>   44
Deed of Cross Charge given by the Company (No. 225411) pursuant to Production
JOA created 18 January 1990 and other charges given by New World Oil &
Developments Pty Ltd, Ampolex Varanus Pty Ltd, Apache Northwest Pty Ltd, Hardy
Petroleum Limited, Novus UK (Harriet) Limited, Tap (Harriet) Pty Ltd and Kufpec
Australia Pty Ltd in favour of the Company pursuant to that JOA;

Harriet Joint Venture and East Spar Joint Venture Access Agreement (Varanus
Island) dated 12 December 1996 between the Company, Ampolex Varanus Pty Ltd,
Apache Northwest Pty Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd,
Tap (Harriet) Pty Ltd, Novus UK (Harriet) Limited, New World Oil & Developments
Pty Ltd, Ampolex (A.O.E.) Limited, Apache Oil Australia Pty Ltd, Santos (BOL)
Pty Ltd, WMC Resources Ltd and Apache Energy Limited;

Assignment, Farm-in/Farm-out, Assumption, novation and covenant documentation
registered as dealings against the Titles, or any predecessor title thereof in
the Registers maintained under the Petroleum Legislation.

SALES CONTRACTS

GAS

Heads of Agreement for the Purchase of Natural Gas from the Harriet Area dated
12 December 1990 between SECWA, Hadson Australia Development Pty Ltd, Hardy
Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni Oil Australia Pty Ltd,
Petro Energy Limited, the Company, Ampolex Varanus Pty Ltd, Swedish Exploration
Consortium AB and New World Oil & Developments Pty Ltd;

Heads of Agreement for Gas Supply and Purchase (Normandy Power) dated 24
October 1994 between Normandy Power Pty Ltd, the Company, Ampolex Varanus Pty
Limited, Hadson Australia Development Pty Ltd, Hardy Petroleum Limited, Kufpec
Australia Pty Ltd, Marubeni Oil Australia Pty Ltd, Monument Oil (Australia)
Limited, New World Oil & Developments Pty Ltd and Petro Energy Limited;


Gas Supply and Purchase Agreement dated 21 July 1995 between Apache Northwest
Pty Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni Oil
Australia Pty Ltd, Monument Oil (Australia) Limited, New World Oil &
Developments Pty Ltd, the Company, Ampolex Varanus Pty Ltd, Doral Resources NL,
Pan Pacific Petroleum NL, Haoma Petroleum Pty Ltd, Strata Petroleum Pty Ltd,
Carnarvon Oil & Gas NL and Roy Antony Radford;

Interim Gas Agreement dated on or about 19 February 1996 between the Company,
Ampolex Varanus Pty Limited, Apache North West Pty Ltd, Hardy Petroleum
Limited, Kufpec Australia Pty Limited, Marubeni Oil Australia Pty Limited,
Novus UK (Harriet) Limited, New World Oil & Developments Pty Limited, Ampolex
(A.O.E.) Limited, Apache Oil Australia Pty Limited, Parker & Parsley
Australasia Limited and Western Mining Corporation Limited;

       
       
                                             43.

<PAGE>   45
Gas Supply and Purchase Agreement (Alcoa) dated 5 June 1996 between Alcoa of
Australia Limited, the Company, Ampolex Varanus Pty Limited, Apache North West
Pty Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni Oil
Australia Pty Ltd, New World Oil & Developments Pty Ltd and Novus UK (Harriet)
Limited;

Wiluna Gas Sales Agreement dated 8 April 1997 between Apache Northwest Pty Ltd,
Hardy Petroleum Limited, Kufpec Australia Pty Ltd, TAP (Harriet) Pty Ltd, Novus
UK (Harriet) Limited, New World Oil & Developments Pty Limited, the Company,
Ampolex Varanus Pty Ltd and Wiluna Gold Pty Limited;

Gas Sale Agreement (Boral) dated 17 June 1997 between Boral Gas (WA) Pty
Limited, the Company, Ampolex Varanus Pty Ltd, Apache Northwest Pty Ltd, Hardy
Petroleum Limited, Kufpec Australia Pty Ltd, TAP (Harriet) Pty Ltd, Novus UK
(Harriet) Limited and New World Oil & Developments Pty Ltd.

CRUDE

Harriet Oilfield Royalty Agreement dated 20 September 1989 between Jeffrey Carr
(Minister for Administration of PSLA (W.A.)), Bond Corporation Pty Ltd, Hadson
Australia Development Pty Ltd, Varanus Pty Ltd, TEA Australia Inc., Petro
Energy Limited and New World Oil & Developments Pty Ltd;

Terms and Conditions of Sale of Varanus Crude dated 18 December 1996 between
Ampolex Varanus Pty Limited and Glencore International AG.





                                     44.

<PAGE>   46
                                  SCHEDULE SIX
                           PROCEDURES FOR INDEPENDENT
                            ACCOUNTANT DETERMINATION


1.        REFERRALS TO EXPERT

          Wherever in this Agreement any matter is to be referred to the
          Independent Accountant, then the terms of this Schedule shall apply.

2.        APPOINTMENT

          The procedure for appointing the Independent Accountant is as
          follows:

2.1       The disputing Party must give written notice including details of the
          matter to be resolved by the Independent Accountant to the other
          Party.

2.2       If the matter is not resolved within FOURTEEN (14) days from the date
          of the notice, the Parties shall agree on a single accountant to
          determine the dispute or, if no agreement is reached within FIVE (5)
          Business Days, a chartered accountant nominated by the President of
          the Institute of Chartered Accountants in Australia being a person
          who is not a partner, consultant or employee of the Buyer's
          accountants or the Seller's accountants and at which time is not or
          which firm for he or she works is not retained by the Buyer, the
          Seller or any of their Related Bodies Corporate in any capacity
          whatsoever.

2.3       DUTY OF DISCLOSURE

          Any person appointed as the Independent Accountant shall fully
          disclose any interest which may conflict with the appointment before
          accepting such appointment and, with the agreement of both Parties,
          shall be entitled to act as such expert, notwithstanding that he or
          she has, or may have, some interest which conflicts with such
          appointment.

2.4       POWERS AND DUTIES

          An Independent Accountant shall, within TEN (10) days of his or her
          acceptance of the appointment, fix a reasonable time and place for
          receiving submissions or information from the Parties or any other
          persons that he or she may think fit and may make further enquiries
          and require such other evidence as he or she considers necessary and
          shall determine the matter with all due diligence.

2.5       NOT ARBITRATOR

          The Independent Accountant shall not be an arbitrator but shall give
          his or her decision as an expert and the provisions of the Commercial
          Arbitration Act 1985 shall not apply to the expert, the determination
          or the determination procedure.





                                      45.

<PAGE>   47
2.6       DETERMINATION BINDING

          The Independent Accountant's determination shall be final and binding
          upon the Parties except for fraud, mistake or manifest error.

2.7       COSTS

          Each Party shall bear the costs and expenses of any consultants,
          witnesses and employees retained by it in connection with the matter,
          but the costs and expenses of the Independent Accountant shall be
          apportioned equally between the Parties.

2.8       REMOVAL OF INDEPENDENT ACCOUNTANT

          If the Independent Accountant has not made a determination within
          SIXTY (60) days of his appointment, either Party may, by notice,
          terminate such appointment.

2.9       APPOINTMENT OF REPLACEMENT

          In the event of such termination, a new Independent Accountant shall
          be appointed within TEN (10) days and the matter determined in
          accordance with this Schedule.


2.10      CONTINUED PERFORMANCE OF OBLIGATIONS

          The referral of a matter to the Independent Accountant shall not
          affect the obligations of the Parties to perform or pay any amount
          otherwise due in accordance with the terms and conditions of the
          Agreement.





                                      46.

<PAGE>   48
                                 SCHEDULE SEVEN
       SPECIAL PURPOSE FINANCIAL REPORT OF THE COMPANY AS AT 30 JUNE 1997





                                   [OMITTED]





                                      47.

<PAGE>   49
                                 SCHEDULE EIGHT
                           WORKING CAPITAL STATEMENT





                                   [OMITTED]





                                      48.


<PAGE>   1
                                                                    EXHIBIT 2.3



                              SHARE SALE AGREEMENT
                          AMPOLEX VARANUS PTY LIMITED


                                AMPOLEX LIMITED
                                ACN 000 113 217

                                      and

                             APACHE ENERGY LIMITED
                                ACN 009 301 964











<PAGE>   2




THIS AGREEMENT is made 8th October 1997

BETWEEN

AMPOLEX LIMITED ACN 000 113 217 of Level 29, 250 St Georges Terrace, Perth,
Western Australia (SELLER)

AND

APACHE ENERGY LIMITED ACN 009 301 964 of Level 3, 256 St Georges Terrace,
Perth, Western Australia (BUYER)

RECITALS:

A.   The Company is engaged in the business of producing oil and gas in Western
     Australia.

B.   The Seller is the legal and beneficial owner of the Shares being the whole
     of the issued share capital of the Company.

C.   The Seller has agreed to sell the Shares to the Buyer, and the Buyer has
     agreed to purchase the Shares from the Seller on the terms and conditions
     set out in this Agreement.

The Parties AGREE:

1.   DEFINITIONS

1.1  Unless otherwise required by the context or subject matter:

     ADJUSTMENT AMOUNT is defined in clause 6.4;

     AGREED RATE means the THIRTY (30) day Bank Bill Swap Reference Rate
     (source Bloomberg) published in the Australian Financial Review in respect
     of the first Business Day of each month or part month for which interest
     is to be calculated;

     AGREEMENT means this agreement as amended, supplemented or varied from
     time to time;

     ASSETS means the interest of the Company as listed in Schedule One and in
     Schedule Five in and under:

     (a)    the Titles and all other rights, titles and interests in the Titles
            subject to the terms and conditions of their grant;



                                      1.
<PAGE>   3

     (b)    the Joint Venture Contracts, including any joint venture property
            held under those contracts;

     (c)    the Information; and

     (d)    all other miscellaneous assets, rights, property and interests
            associated or employed in relation to the Assets, including the
            right to produce Petroleum in accordance with that interest;

     BALANCE SHEET means the balance sheet of the Company as audited by Ernst &
     Young annexed as Schedule 7 prepared on the basis set out in the notes to
     the Balance Sheet;

     BANK ACCOUNT means any bank account in the name of the Company;

     BUSINESS DAY means a day (during the hours of 9.00am to 5.00pm Perth time)
     on which trading banks are open for business in Perth, Western Australia;

     BUYER ACCOUNT means an account of amounts owed by the Buyer to the Seller
     determined under Schedule 4;

     BUYER'S SOLICITORS means Arthur, Robinson & Hedderwicks of 530 Collins
     Street, Melbourne, Victoria;

     COMPANY means Ampolex Varanus Pty Limited (ACN 009 708 089);

     COMPLETION means completion of the sale and purchase of the Shares under
     Clause 9;

     COMPLETION DATE means the later of:

     (a)    14 November 1997; or

     (b)    the day falling FIVE (5) Business Days after the Conditions are
            satisfied; or

     such other date as the Parties may agree in writing;

     CONDITION means any conditions specified in clauses 3 and 4 inclusive and
     CONDITIONS means all of them;

     DOLLARS or $ means Australian dollars unless otherwise stated;

     EFFECTIVE DATE means 00.01am, 1 July 1997 (Perth time);

     ENCUMBRANCE means a mortgage, charge, whether fixed or floating, bill of
     sale, pledge, lien, charging order, stop order, writ of execution, title
     retention or conditional sales agreement, hire or hire purchase agreement,
     lease, licence to use



                                      2.
<PAGE>   4


     or occupy, option, restriction as to transfer, use or possession,
     easement, caveat and the claim stated in that caveat, equity interest and
     any other security interest or other third party right or interest;

     GOVERNMENTAL AGENCY means any government or governmental,
     semi-governmental, administrative, fiscal or judicial body, department,
     commission, authority, tribunal, agency or entity;

     INDEPENDENT ACCOUNTANT means the chartered accountant referred to in
     Schedule Six;

     INFORMATION means geological, geophysical or technical information within
     the custody or control of the Company being material information that
     relates to the presence, absence or extent of hydrocarbon deposits in the
     area of the Assets and has been obtained from the exploration and
     prospecting for or production of hydrocarbons within Assets including,
     without limitation, the books, records, seismic and interpretive data,
     notes, drawings, maps and other information (in various media) related to
     the Assets;

     INTERIM PERIOD means the period between the Effective Date and the
     Completion Date;

     JOINT VENTURE means all or any of, as the context requires, the
     relationships established under the Joint Venture Contracts;

     JOINT VENTURE CONTRACTS means the contracts listed as such in Schedule
     Five;

     OPERATOR means Apache North West Pty Ltd except in relation to Exploration
     Licence WA-192-P in respect of which Tap (Harriet) Pty Ltd has been
     appointed Operator;

     OTHER AGREEMENTS means:

     (a)    an agreement entered into on the date of this Agreement between
            Ampolex (PNG Holdings) Inc and the Buyer or a Related Body
            Corporate of the Buyer for the sale of the issued shares in Ampolex
            (Western Australia) Inc.; and

     (b)    an agreement entered into on the date of this Agreement between
            Ampolex Limited and the Buyer or a Related Body Corporate of the
            Buyer for the sale of the issued shares in Ampolex (A.O.E.) Pty
            Limited;

     PARTY means the Seller or the Buyer according to the context and PARTIES
     means both the Seller and the Buyer;

     PETROLEUM has the meaning given in the Petroleum (Submerged Lands) Act
     (WA) 1982;


                                      3.
<PAGE>   5


     PETROLEUM LEGISLATION means the Petroleum Act (WA) 1967, the Petroleum
     (Submerged Lands) Act (Cth) 1967, the Petroleum (Submerged Lands) Act (WA)
     1982, the Petroleum Pipelines Act (WA) 1969 any other Act of Parliament
     with which each Act is incorporated, as well as all regulations,
     administrative directions and determinations made under any of those Acts;

     PURCHASE PRICE means the cash consideration of SEVEN MILLION AND FIVE
     THOUSAND THREE HUNDRED AND SEVENTY TWO DOLLARS AND SIXTY FOUR CENTS
     ($7,005,372.64) (which amount includes working capital as at the Effective
     Date) as adjusted in accordance with Clause 6 and Schedule Four, plus
     interest at the Agreed Rate calculated daily and compounded monthly during
     the Interim Period;

     RELATED BODY CORPORATE has the meaning given to that expression in the
     Corporations Law;

     SALE means the sale and purchase of the Shares in accordance with the
     terms of this Agreement;

     SALES CONTRACTS means the contracts listed as such in Schedule 5;

     SCHEDULE means a schedule to this Agreement;

     SELLER ACCOUNT means an account of amounts owed by the Seller to the Buyer
     determined under Schedule 4;

     SELLER'S SOLICITORS means Freehill, Hollingdale & Page of 140 St Georges
     Terrace, Perth, Western Australia;

     SHARES means the 7,102 shares in the Company having a par value of $0.50
     being all the issued shares in the capital of the Company;

     SPECIFIED ENCUMBRANCES means the encumbrances specified in Schedule One;

     TAX means all federal, state, local or foreign taxes and charges including
     but not limited to income, gross receipts, windfall profits, goods and
     services, value added, transfer, property, sales, production, use,
     license, excise, franchise, withholding or similar taxes, together with
     any interest, additions or penalties and any interest in respect of such
     additions or penalties;

     TITLES means the petroleum titles and licences specified in Schedule One;
     and

     WARRANTIES mean the warranties and representations set out in:-

     (a)    Schedule Two in the case of the Seller; and


                                      4.
<PAGE>   6


     (b)    Schedule Three in the case of the Buyer.

2.   SALE SUBJECT TO CONDITIONS

     The Sale is conditional on satisfaction of each and every Condition.

3.   HART-SCOTT-RODINO CONDITION

     This Agreement is subject in all respects to and conditional upon
     compliance by the Parties with the Hart-Scott-Rodino Antitrust
     Improvements Act of 1976, and rules and regulations promulgated pursuant
     thereto in respect of the transactions contemplated by this Agreement and
     the Other Agreements.

4.   FIRB CONDITION

4.1  DEFINITION

     In this subclause:

     ACT means the Foreign Acquisitions and Takeovers Act 1975; and

     TREASURER means the Treasurer of Australia.

4.2  SALE SUBJECT TO APPROVAL

     The Sale is conditional on the Treasurer either:

     (a)    advising the Buyer that the Treasurer has no objection to the
            acquisition of the Shares by the Buyer and the transactions
            contemplated by the Other Agreements either:

            (i)    unconditionally; or

            (ii)   subject to conditions with which the Buyer (or its Related 
                   Body Corporate, as the case may be) is willing to comply;
                   or

     (b)    ceasing to be empowered under the Act to make an order prohibiting
            the acquisition of the Shares by the Buyer and the transactions
            contemplated by the Other Agreements;

     whichever occurs first.

4.3  NOTICE TO BE GIVEN TO TREASURER

     The Buyer must:

     (a)    give notice to the Treasurer under section 25 of the Act in the
            prescribed form; and


                                      5.
<PAGE>   7

     (b)    comply with all directions on that form;

     within TEN (10) Business Days from the date of this Agreement.

4.4  PARTIES' OBLIGATIONS


     (a)    The Buyer must use all reasonable endeavours to obtain the approval
            of the Treasurer to the Sale under the Act.

     (b)    The Parties' must (and the Seller must ensure that the Company
            will) do all things and provide all information and documents
            required by the Treasurer or the Foreign Investment Review Board in
            connection with the application for approval of the Sale under the
            Act as soon as reasonably practicable after being notified of the
            required things, information or documents.

4.5  BENEFIT OF CONDITION

     This Condition:

     (a)    is for the benefit of the Seller and the Buyer; and

     (b)    may not be waived.

4.6  CONDITION NOT FULFILLED

     If approval of the Treasurer is denied then:

     (a)    the Sale will terminate automatically without notice; and

     (b)    subject to the rights of either Party in respect of any antecedent
            breach of the provisions of this Agreement:

            (i)     neither the Seller nor the Buyer will have any claim 
                    against the other; and

            (ii)    this Agreement, other than this subclause, will have no 
                    further effect.

5.   SALE AND PURCHASE

     At Completion, the Seller agrees to sell and transfer to the Buyer, and
     the Buyer agrees to purchase from the Seller the Shares free from
     Encumbrances for the Purchase Price on the terms and conditions of this
     Agreement.


                                      6.
<PAGE>   8


6.   CONSIDERATION

6.1  PURCHASE PRICE

     The Buyer shall pay the Seller the Purchase Price subject to any
     adjustments required by this Agreement.

6.2  BUYER ACCOUNT

     The Buyer must pay to the Seller in addition to the Purchase Price the
     amount charged to the Buyer Account plus interest at the Agreed Rate
     calculated daily and compounded monthly.

6.3  SELLER ACCOUNT

     The Seller must pay by way of a deduction to the Purchase Price the amount
     charged to the Seller Account plus interest at the Agreed Rate calculated
     daily and compounded monthly.

6.4  PAYMENT

     Other than in respect of the amounts agreed or determined under Schedule
     Four, the payments under this Clause shall be paid at Completion and the
     Buyer Account and the Seller Account may be offset so that only one
     payment is made as between the Buyer and the Seller (ADJUSTMENT AMOUNT).

6.5  POST COMPLETION/FINAL ADJUSTMENT

     Any matters not finally determined by and paid on the Completion Date will
     be resolved and payment made pursuant to the procedure described in
     Schedule Four.

6.6  FURTHER ADJUSTMENT

     If at any time during the period of THREE (3) years following the
     Completion Date the:

     (a)    Buyer becomes:

            (i)     entitled to or receives funds, revenues, refunds, credits 
                    or payments; or

            (ii)    liable to pay (and subject to this clause, does or agrees 
                    to pay) costs, expenses and expenditure;

            which are attributable to the Assets and relate to the period 
            before the Effective Date; or


                                      7.
<PAGE>   9


     (b)    Seller becomes:

            (i)     entitled to or receives funds, revenues, refunds, credits 
                    or payments; or

            (ii)    liable to pay (and subject to this clause, does or agrees 
                    to pay) costs, expenses and expenditure;

            which are attributable to the Assets and relate to the period
            after the Effective Date;

     (in all cases, which amounts or liabilities were not otherwise
     specifically adjusted for in this Agreement), in an amount or amounts
     aggregating or exceeding not less than TEN THOUSAND DOLLARS ($10,000.00)
     then

     (c)    the Buyer shall account to the Seller within THIRTY (30) days of
            such adjustments in respect of paragraphs 6.6(a)(i) and 6.6(b)(ii);
            and

     (d)    the Seller shall account to the Buyer within THIRTY (30) days of
            such adjustments in respect of paragraphs 6.6(a)(ii) and 6.6(b)(i),

     for such funds, revenues, liabilities, costs, expenses, refunds, credits
     or payments and, where an amount relates partially to periods before and
     after the Effective Date, then the amount shall be equitably apportioned
     between the Seller and the Buyer. A Party shall be entitled to set off
     amounts payable by the other Party in making account to that other Party.
     A reference to the Buyer and the Seller in paragraphs (a) and (b) of this
     Clause includes a reference to the Company, where the Company receives an
     amount or incurs a liability to be adjusted under this clause.

7.   ACCESS TO COMPANY RECORDS

     From the date of this Agreement, the Seller shall and shall cause the
     Company to allow reasonable access by the Buyer to all of the Company's
     books, accounts and documents in connection with the Company and the
     Shares, and information concerning the Company relevant to the Sale.

8.   PERIOD BEFORE COMPLETION

8.1  CARRYING ON OF BUSINESS

     The Seller shall cause that between the date of execution of this
     Agreement and the Completion Date:

     (a)    the Company informs and consults with the Buyer on all material
            matters relating to the conduct of the business of the Company and
            will procure that such business is conducted in a diligent and
            ordinary and usual manner. In particular, but without prejudice to
            the generality of the foregoing, the Seller



                                      8.
<PAGE>   10


            will procure that the Company consults with the Buyer before the
            Company:

            (i)     approves any new or varied programme and budget of 
                    operations;

            (ii)    approves any drilling operations which are not at the date 
                    of this Agreement approved or identified in an approved 
                    programme and budget;

            (iii)   approves any other matter likely to affect in any material
                    respect the nature or extent of expenditure obligations of
                    the Company;

            (iv)    in any other respect, exercises any voting right under any 
                    Joint Venture Contract;

     (b)    the Company does not acquire or dispose of any Asset, other than
            acquisitions or disposals of Petroleum, stocks or receivables in
            the ordinary course of business without the prior written consent
            of the Buyer;

     (c)    the Company does not create any Encumbrances over any of the Assets
            without the prior written consent of the Buyer;

     (d)    the Company pays when due all cash calls under the Joint Venture
            Contracts;

     (e)    the Company does not vary the terms of sale of its share of
            Petroleum derived from the Assets pursuant to the Sale Contracts;

     (f)    without the prior written approval of the Buyer (which approval
            shall not be unreasonably withheld), the Company will not:-

            (i)     give notice of or otherwise institute in any sole risk or
                    non-consent operation;

            (ii)    farm-out the Assets;

            (iii)   surrender or relinquish of any part of the Assets; or

            (iv)    execute any instrument amending, waiving or cancelling any
                    provision of the Joint Venture Contracts;

     (g)    the Company provides to the Buyer copies of all material notices
            issued by the Operator in respect of the Assets;

     (h)    the Company does not issue any shares, options or securities which
            are convertible into shares in the Company;

     (i)    the Company does not engage any employees;


                                      9.
<PAGE>   11


     (j)    the Company does not alter its memorandum or Articles of
            Association without the prior written consent of the Buyer;

     (k)    the Company does not incur any liabilities, enter into any contract
            or commitment or engage in any activity other than in the ordinary
            course of business; and

     (l)    the business of the Company is conducted so as to comply in all
            material respects with all applicable laws and regulations

     PROVIDED THAT the Seller will not be liable to the Buyer for any breach of
     an obligation imposed in this Clause 8.1 which arises from any course of
     action, to the extent that the Seller has consulted with the Deputy
     Managing Director of the Buyer prior to undertaking such course of action
     and the Buyer has not objected in writing as soon as practicable after
     such consultation.

8.2  ACCESS TO INFORMATION

     (a)    In addition to its obligations under Clause 8.1, the Seller will
            procure that the Company will, subject to any confidentiality
            restrictions contained in the Joint Venture Contracts and this
            Agreement and subject to reasonable notice, give the Buyer
            reasonable access to the Information and any other matters relating
            to the Assets during normal working hours and provide copies
            thereof, at the Buyer's cost.

     (b)    In exercising its rights under Clause 8.2(a), the Buyer will not
            unreasonably interfere with the business or operations of the
            Seller or the Company.

     (c)    If this Agreement is terminated for whatever reason, the Buyer must
            promptly return all Information to the Seller.

8.3  INSURANCE

     During the Interim Period, the Seller will ensure that the Company
     maintains the insurances taken out in respect of the Assets as at the
     Effective Date. These insurances will be at the cost of the Buyer and
     adjusted for under Schedule 4.

9.   COMPLETION

9.1  COMPLETION LOCATION

     Completion will take place at the Seller's Solicitors' office.

9.2  COMPLETION DATE

     The Parties must effect Completion on the Completion Date at a time agreed
     by the Buyer and the Seller.



                                      10.
<PAGE>   12


9.3  SELLER'S OBLIGATIONS

     At Completion, the Seller must deliver to the Buyer:

     (a)    a duly executed but unstamped transfer of the Shares, together with
            the relevant share certificates;

     (b)    (i)     the common seal and any duplicate or official seals;

            (ii)    any Memorandum and Articles of Association of the Company 
                    in the possession of the Seller;

            (iii)   all minutes of meetings of directors and shareholders of 
                    the Company;

            (iv)    all registers of the Company;

            (v)     copies of all income tax returns lodged by the Company  
                    before the Completion Date and supporting tax return work
                    papers in possession of the Company;

            (vi)    all books, ledgers, records and other documents and data of
                    the Company in either written or electronic form; and

            (vii)   a signed notice to each Purchaser under the Sale Contracts 
                    nominating a new Bank Account into which proceeds of sale
                    of Petroleum can be made;

     (c)    a legal opinion by the Seller's Solicitors in a form reasonably
            satisfactory to the Buyer and the Buyer's Solicitors stating that
            this Agreement is, and will be, enforceable against the Seller in
            all respects in accordance with its terms;

     (d)    a certificate signed on behalf of the Seller by two authorised
            officers (AUTHORISED OFFICERS) stating that all the representations
            and warranties given by the Seller in this Agreement are true and
            correct as at Completion and that the Seller is not in breach of
            any of its obligations under this Agreement;

     (e)    copies of board resolutions certified as true and correct by an
            Authorised Officer in which the directors of the Seller authorise
            the execution of this Agreement and the performance of the Seller
            of the transactions contemplated by this Agreement;

     (f)    certificates of incumbency in respect of each Authorised Officer
            confirming the authority of each of them to sign the certificate
            referred to in Clause 9.3(e) on behalf of the Seller; and



                                      11.
<PAGE>   13

     (g)    the Adjustment Amount, if the Seller Account plus interest at the
            Agreed Rate calculated daily and compounded monthly is greater than
            the Buyer Account plus interest at the Agreed Rate calculated daily
            and compounded monthly.

9.4  OTHER OBLIGATIONS OF SELLER ON COMPLETION

     As part of Completion, on payment of the Purchase Price and subject to
     Clause 9.5(a), payment of the Adjustment Amount to the Seller, the Seller
     shall cause the directors of the Company to hold a meeting with effect at
     Completion at which the directors, in accordance with the Company's
     articles of association:

     (a)    appoint the Buyer's nominees as additional directors of the
            Company;

     (b)    appoint the Buyer's nominee as an additional secretary of the
            Company;

     (c)    approve for registration, subject to payment of stamp duty, the
            transfer of the Shares to the Buyer;

     (d)    (i)     authorise the signature of all authorities necessary to 
                    revoke all existing authorities to bankers in relation to
                    the operation of the Bank Accounts; and

            (ii)    appoint, in the manner the Buyer directs, the Buyer's
                    nominees as the persons authorised to operate the Bank
                    Accounts.

     (e)    table and accept resignations of:

            (i)     the public officer;

            (ii)    the secretary, other than the secretary nominated by the 
                    Buyer; and

            (iii)   the directors, other than the directors nominated by the 
                    Buyer;

            to take effect on and from the close of business of the meeting; 
            and

     (f)    sign all forms required to be signed by the outgoing directors and
            secretary under the Corporations Law.

9.5  THE BUYER'S OBLIGATIONS AT COMPLETION

     At Completion, the Buyer must:

     (a)    by means of confirmed electronic funds transfer to a bank account
            in the name of the Seller as nominated by the Seller to the Buyer
            for value at Completion in Australian dollars pay to the Seller the
            Purchase Price and, if the Buyer Account plus interest at the
            Agreed Rate calculated daily and compounded monthly is greater than
            the Seller Account plus interest at the 


                                      12.
<PAGE>   14

            Agreed Rate calculated daily and compounded monthly, the Adjustment
            Amount; and

     (b)    deliver to the Seller:

            (i)     a legal opinion by the Buyer's Solicitors in a form 
                    reasonably satisfactory to the Seller and the Seller's
                    Solicitors, stating that this Agreement is, and will be,
                    enforceable against the Buyer in all respects in accordance
                    with its terms;

            (ii)    a certificate signed on behalf of the Buyer by two 
                    authorised officers (AUTHORISED OFFICERS) stating that all
                    the representations and warranties given by the Buyer in
                    this Agreement are true and correct as at Completion and
                    that the Buyer is not in breach of any of its obligations
                    under this Agreement;

            (iii)   copies of board resolutions certified as true and correct 
                    by an Authorised Officer in which the directors of the
                    Buyer authorise the execution of this Agreement and the
                    performance of the Buyer of the transactions contemplated
                    by this Agreement; and

            (iv)    certificates of incumbency in respect of each Authorised 
                    Officer confirming the authority of each of them to sign
                    the certificate referred to in paragraph (ii) on behalf of
                    the Buyer. 

9.6  COMPLIANCE

     Neither the Buyer nor the Seller will be obliged to proceed to Completion
     unless:

     (a)    there is no material breach of Clause 8 which remains unremedied;
            and

     (b)    the other of them complies with all of its obligations under this
            Clause 9.

9.7  OTHER DOCUMENTS

     As soon as possible after Completion, the Seller will cause to be
     delivered at the Buyer's cost to the Buyer:

     (a)    all technical and other data, books, records, accounts, contracts,
            maps, notes, drawings and other information (regardless of form)
            constituting the Information in the possession and the control of
            the Seller requested by the Buyer; and

     (b)    all original Joint Venture Contracts and Sales Contracts (to the
            extent that they are in the possession of or under the control of
            the Seller) or otherwise copies thereof and any other document that
            evidences the Company's title to Assets.


                                      13.
<PAGE>   15


10.  POST COMPLETION

10.1 EXERCISE OF RIGHTS

     From Completion and until the Shares are registered in the name of the
     Buyer, the Seller agrees, in relation to the Shares, at the cost of the
     Buyer, to act in accordance with the directions of the persons appointed
     under clause 9.4(a).

10.2 CHANGE OF NAME

     The Buyer shall cause the Company to change its name to a name not
     associated with the Seller or any Related Body Corporate of the Seller and
     register the proposed change of name with the appropriate regulatory
     authority for approval within ten (10) Business Days of Completion.

10.3 INDEMNITY

     The Buyer indemnifies and holds harmless the Seller from any and all
     liability whatsoever arising out of the implementation of any direction
     given under Clause 10.1.

10.4 POST COMPLETION AUDIT OF OPERATOR'S ACCOUNTS

     (a)    The Buyer acknowledges that for a period of THREE (3) years after
            the Completion Date the Seller retains its rights to participate in
            the audits of the Operator's books to be conducted under the terms
            of the Joint Venture Contracts (subject to any confidentiality
            restrictions contained in the Joint Venture Contracts and the Buyer
            agrees to use its reasonable endeavours to enable the Seller to so
            participate) in respect of the period prior to the Effective Date
            (and may nominate a representative to attend as a representative of
            the Buyer at its own cost) and will be entitled to and responsible
            for any adjustment made to any account maintained under the Joint
            Venture Contracts arising as a result of any such audit in respect
            of the period prior to the Effective Date.

     (b)    If as a consequence of such audit, adjustments are made to any of
            the entries in the Working Capital Statement referred to in
            Schedule Four, a further adjustment will be paid to the Party
            entitled within THIRTY (30) Business Days of the results of that
            audit, provided that no claim can be made under this clause unless
            the net balance due is greater than TEN THOUSAND DOLLARS ($10,000).

10.5 PRESERVATION OF RECORDS

     (a)    The Buyer must, at its own expense, preserve and keep the records
            held by it or the Company relating to the business of the Company
            for a period of SIX (6) years from the Completion Date and shall
            make such records and personnel available to Seller as may be
            reasonably required by Seller in connection with, among other
            things, any insurance claim, legal proceedings,


                                      14.
<PAGE>   16


            the tax affairs of the Seller or any governmental investigation
            (including investigation and audits by any taxing authority)
            relating to the business of the Company prior to the Completion
            Date.

     (b)    The Buyer consents to the Seller retaining copies of all corporate
            and Tax records relating to the Company or the Assets provided that
            the Seller shall not use or disclose them for any purpose other
            than as contemplated under Clause 10.5(a).

11.  TAX REQUIREMENTS

11.1 INFORMATION

     The Seller agrees to make available to the Buyer all information in its
     custody or control relating to the Company or relating to the Assets in
     respect of any period before the Completion Date which the Buyer needs to
     know to enable it to cause the Company to complete any Tax return or to
     make any claim for the undeducted allowable expenditure and the undeducted
     allowable capital expenditure.

11.2 REASONABLE ASSISTANCE

     The Seller agrees to give to the Buyer all reasonable assistance in
     connection with any tax audit of the Company after the Completion Date in
     respect of any period before the Completion Date, provided that the
     Seller's obligation under this clause terminates THREE (3) years after the
     Completion Date.

11.3 BUYER OBLIGATIONS

     The Buyer will not:

     (a)    in relation to any Tax, amend any declaration, election or
            selection, the giving of a notice or the exercise of an option by
            the Company in respect of the period ending before the Completion
            Date without the Seller's prior written consent, which consent
            shall not be unreasonably withheld;

     (b)    fail to submit any income tax return in relation to the Company for
            any period which includes the period commencing on the day
            following the Completion Date and ending at the end of the tax year
            in which the Completion Date occurs; or

     (c)    amend any income tax return of the Company for any tax year ending
            at or prior to the end of the tax year in which the Completion Date
            occurs without the Seller's prior written consent, which consent
            shall not be unreasonably withheld.

     In this clause, "tax year" means a year ending on 30 June or, where the
     company has a substituted accounting period (within Section 18 of the
     Income Tax Assessment Act 1936, as amended) ending on some date other than
     30 June, that date.


                                      15.
<PAGE>   17

11.4 SELLER OBLIGATIONS

     The Seller will not submit any income tax return in relation to the
     Company for any period ending before the Completion Date without the
     Buyer's prior written consent, which consent must not be unreasonably
     withheld.

11.5 U.S. INCOME TAX STATUS

     The Buyer acknowledges that the Company has or will have status as a
     branch of the Seller for United States income tax purposes and agrees that
     the Seller may take all such actions as it deems appropriate for the
     Company to qualify as a branch of the Seller for United States income tax
     purposes in respect of the period prior to and ending on the Completion
     Date.

12.  WARRANTIES

12.1 SELLER

     The Seller makes the Warranties in favour of the Buyer as at the Effective
     Date and as at the Completion Date. The Warranties are made subject to the
     qualifications made in this Agreement and in the Schedules and subject to
     any disclosures made by the Seller in writing on or prior to the date of
     this Agreement.

12.2 BUYER

     The Buyer makes the Warranties in favour of the Seller as at the Effective
     Date and as at the Completion Date. The Warranties are made subject to the
     qualifications made in this Agreement and in the Schedules.

12.3 NO WARRANTY UNLESS EXPRESSLY INCLUDED

     (a)    Save as and only to the extent set forth in Clause 12.1, the Seller
            makes no representations or warranties in respect of any matter or
            thing and disclaims all liability and responsibility for any
            representation, warranty, statement, opinion or information made or
            communicated (orally or in writing) to the Buyer (including,
            without limiting the generality of the foregoing, any
            representation, warranty, statement, opinion, information or advice
            made and communicated to the Buyer by any officer, stockholder,
            director, employee, agent, consultant, counsel or adviser of the
            Seller or a tender document) and the Buyer acknowledges and affirms
            that it has not relied upon any such representation, warranty,
            statement, opinion or information in entering into or carrying out
            the transactions contemplated by this Agreement.

     (b)    Subject to the Warranties, the Buyer acknowledges and affirms that
            it has made its own independent investigation, analysis and
            evaluation of the geological, geophysical and engineering
            interpretations, economic valuations and assessment of tax
            allowances and prospects for development of the Assets and
            acknowledges and affirms that in making the decision to purchase


                                      16.
<PAGE>   18


            the Assets, it has relied to that extent upon its independent
            investigation and those of its representatives, including
            professional, legal, tax, economic, financial, business and other
            advisers.

     (c)    The Buyer acknowledges that subject in all respects to the
            Warranties:

            (i)     it has made its own enquiries and has undertaken 
                    assessments and due diligence with respect to the Company,
                    the Assets and the business conducted by the Company and
                    has satisfied itself as to the Company's interest in the
                    Titles as set out in Schedule 1 and the Joint Venture
                    Contracts set out in Schedule 5, prior to entering into
                    this Agreement;

            (ii)    it and its advisers have completed a review of the
                    financial records of the Company for the purpose of
                    verifying the accounts of the Company;

            (iii)   it has not relied on any representation made by or on
                    behalf of the Seller in making its decision to enter into
                    this Agreement other than the Warranties;

            (iv)    the Seller gives no representation or warranty in respect 
                    of the existence or absence of common law or statutory
                    native title rights in respect of the Assets or whether any
                    claim for native title rights exists or will arise in
                    respect of the Assets and the Buyer acknowledges that it
                    has conducted its own enquiries with respect to native
                    title matters;

            (v)     the Seller is induced to enter into this Agreement in 
                    consequence of these acknowledgments; and

            (vi)    the Seller gives no representation or warranty as to any 
                    Tax balances of the Company, and to the extent Tax balances
                    can be calculated from or derived from the Balance Sheet,
                    any warranty and representation in respect of such
                    balances, their calculation or derivation is denied and the
                    Buyer shall have no claim whatsoever against the Seller in
                    respect thereof.

     (d)    The Buyer agrees that it has actual or constructive knowledge of
            some of the subject matter of the Warranties and any breach of
            Warranty will not be enforceable against the Seller to the extent
            it is shown that the inaccuracy, error or omission underlying the
            alleged breach was known or was constructively known by the Buyer
            at or prior to the time the Buyer entered into this Agreement.

     (e)    Without prejudice to the generality of the foregoing, the Seller
            makes no representations or warranties as to:


                                      17.
<PAGE>   19



            (i)     the amounts of reserves attributable to and the field life 
                    of the Assets;

            (ii)    any geological, geophysical, engineering, economic or other
                    interpretations, forecasts or evaluations; or

            (iii)   whether any Tax allowances will in fact be deductible in
                    the hands of the Company.

12.4 REASONABLE ENQUIRY

     Where any Warranty is qualified by any reference to the knowledge or
     awareness or belief of any Party, there shall be implied in that warranty
     or representation a warranty that such Party has made reasonable enquiries
     concerning the subject matter of that warranty or representation, save
     that it shall not be deemed to have made enquiries of any third party.

12.5 WARRANTIES - DURATION

     The Warranties shall survive the Completion Date for a period of ONE (1)
     year.

12.6 CONSEQUENTIAL LOSS

     Notwithstanding any other provision of the Agreement, a Party shall not
     under any circumstances be liable to the other under, arising out of or in
     any way connected with this Agreement for any consequential loss or damage
     whether arising in contract or tort (including negligence or breach of any
     statutory duty). For the purposes of this clause, consequential loss
     includes but is not limited to, any obligation or inability to produce
     Petroleum, lost production or loss of profits howsoever arising.

12.7 LIMITATION ON CLAIMS

     The Buyer's right to claim for and seek indemnity in respect of any claim
     (whether relating to a breach of the Warranties or otherwise relating to
     the subject matter of this Agreement) is limited as follows:

     (a)    the Buyer must give written notice to the Seller of the specific
            claim in question with reasonable details of the relevant claim,
            including, if possible, the Buyer's estimate of the amount of the
            claim, on or before the first anniversary of the Completion Date;

     (b)    the Buyer can only bring a claim for breach of a Warranty or
            otherwise relating to the subject matter of this Agreement if the
            amount reasonably claimed exceeds (or where there is more than one
            claim they exceed the aggregate) ONE HUNDRED THOUSAND DOLLARS
            ($100,000.00);

     (c)    the maximum aggregate amount which the Buyer may recover from the
            Seller for breach of the Warranties is the Purchase Price.



                                      18.
<PAGE>   20

12.8 CONDUCT OF CLAIMS

     If the Buyer receives a claim from a third party which may give rise to a
     claim against the Seller under this Agreement, the Buyer must within TEN
     (10) Business Days of receipt, notify the Seller of the claim giving full
     details so far as practicable and, if the Seller indemnifies the Buyer and
     the Company to their reasonable satisfaction against all and any costs,
     charges and expenses which may be incurred or for which they may become
     liable, the Buyer must take such action as the Seller reasonably instructs
     to avoid, dispute, resist, appeal, compromise or defend any such claim and
     any adjudication in respect of it.

12.9 BUYER'S REMEDIES

     (a)    Prior to the Completion Date, the Buyer may only rescind this
            Agreement in accordance with Clause 12.9(b).

     (b)    If not less than THREE (3) Business Days before the Completion
            Date, the Buyer becomes aware that the Seller is in breach of any
            of the Warranties of the Seller or any other material provision of
            this Agreement that has a material adverse effect on the value of
            the Shares as at the Effective Date, the Buyer shall promptly
            provide the Seller with written notice containing reasonable
            details of the said breach in which case the Completion Date shall
            be automatically extended for a period of TEN (10) Business Days.
            The Parties will use all reasonable efforts to resolve the matter,
            failing which the Buyer may not less than THREE (3) Business Days
            prior to the extended Completion Date, by notice in writing to the
            Seller elect to:

            (i)     proceed to Completion on the extended Completion Date, 
                    whereupon no Party shall have any further liabilities or
                    obligations to the other whatsoever in respect of the
                    breach notified; or

            (ii)    (without prejudice to any other right or other remedy it 
                    may have and subject always to Clause 12.7) rescind this
                    Agreement.

12.10 NON-MERGER OF WARRANTIES

      No Warranties merge on Completion.

12.11 RECLAMATION OBLIGATIONS

      All costs, expenses, risks, liabilities and obligations respecting the
      abandonment of any wells which are part of the Assets, closure,
      decommissioning and dismantling the facilities of the Company and any
      reclamation and restoration of all sites shall be borne and paid for
      solely by the Buyer, its successors or assigns, and the Buyer, its
      successors or assigns, shall indemnify, defend and save harmless the
      Seller from and against any claims or demands (including breach of
      statutory duty) by any person for or resulting in expense, liability,
      loss, costs, claims or damages direct or indirect (including the effects
      of, and the costs of complying with any order


                                      19.
<PAGE>   21


      direction, or claim of any government or agency having jurisdiction)
      pertaining to the foregoing operations conducted or failed to be
      conducted by the Buyer, its successors or assigns after Completion.

12.12 BUYER'S INDEMNITY-ENVIRONMENTAL DAMAGE

      (a)    The Buyer, its successors or assigns, shall, after Completion, be
             liable to the Seller for all loss, costs, damages or expenses
             which the Seller may suffer and, in addition, shall indemnify,
             defend and save harmless the Seller from and against any claims or
             demands (including breach of statutory duty) or damages, direct or
             indirect, before, on and after Completion (including the effects
             of, and the costs of complying with, any order, direction, or
             claim of any government or agency having jurisdiction) arising out
             of or resulting from Environmental Damage caused or alleged to
             have been caused in respect of the Assets.

      (b)    For the purpose of this clause:

             ENVIRONMENTAL DAMAGE means any one or more of:

             (i)    ground water, surface water or aquifer contamination;

             (ii)   soil contamination;

             (iii)  corrosion or deterioration of structures, equipment, fences
                    and other property;

             (iv)   toxic or hazardous substance releases or emissions;

             (v)    death or injury to human beings caused in whole or in part 
                    by any of items (i) through (iv) above;

             (vi)   death or injury to plants and animals  caused in whole or 
                    in part by any of items (i) through (iv) above; and

             (vii)  natural resource damages.

13.   TERMINATION AND DAMAGES

13.1  RIGHT TO TERMINATE

      If not less than THREE (3) Business Days before the Completion Date, the
      Buyer is in breach of any of the Warranties of the Buyer or any other
      material provision of this Agreement such that the interest of the Seller
      under this Agreement is materially adversely affected, then the Seller
      shall promptly provide the Buyer with written notice containing
      reasonable details of the said breach in which case the Completion Date
      shall be automatically extended for a period of TEN (10) Business Days.
      The Parties will use all reasonable endeavours to resolve the


                                      20.
<PAGE>   22

      matter, failing which the Seller may not less than THREE (3) Business
      Days prior to the extended Completion Date, by notice in writing to the
      Buyer elect to:

      (a)    complete this Agreement on the extended Completion Date, whereupon
             no Party shall have any further liabilities or obligations to the
             other whatsoever in respect of the breach notified; or

      (b)    terminate its obligations under this Agreement, without prejudice
             to any right or other remedy it may have against the Buyer.

13.2  REMEDY

      The Seller may not give a notice under Clause 13.1(a) or (b) to the Buyer
      where the breach is capable of remedy and has been remedied by not less
      than THREE (3) Business Days before the extended Completion Date.

13.3  OTHER TERMINATION RIGHTS

      Either the Buyer or the Seller may terminate this Agreement by written
      notice to the other of them where:

      (a)    the other of them convenes a meeting of its creditors or proposes
             or enters into a scheme of arrangement or composition with its
             creditors;

      (b)    there is a liquidation of the other of them;

      (c)    a receiver or receiver and manager is appointed to the other of
             them;

      (d)    a person holding a security interest over the assets of the other
             of them takes or attempts to take possession of those assets;

      (e)    an administrator is appointed to the other of them under Part 5.3A
             of the Corporations Law; or

      (f)    the other Party repudiates its obligations under this Agreement.

14.   COSTS, EXPENSES AND DELAYED PAYMENT

14.1  STAMP DUTY

      (a)    The Buyer must pay any stamp duty in respect of the execution,
             delivery and performance of this Agreement and any agreement or
             document entered into or signed in contemplation of this
             Agreement.

      (b)    The Buyer must pay any fine, penalty or other cost in respect of a
             failure to pay any stamp duty for which it is responsible under
             Clause 14.1(a), except to the extent that the fine, penalty or
             other cost is caused by an act or default on the part of the
             Seller.


                                      21.
<PAGE>   23

      (c)    The Buyer must within FIFTEEN (15) Business Days of the date of
             this Agreement submit this Agreement for an assessment of stamp
             duty and use its reasonable endeavours to secure and pay an
             assessment in respect of this Agreement as soon as practicable and
             will keep the Seller appraised of progress. The Seller agrees to
             assist the Buyer when requested and, in particular, to respond to
             requisitions (if any) for further information.

14.2  COSTS AND EXPENSES

      Subject to Clause 14.1, each Party must pay its own costs and expenses in
      respect of the negotiation, preparation, execution, delivery and
      registration of this Agreement or other Agreement or document entered
      into or signed in connection with the subject matter of this Agreement.

14.3  LATE INTEREST

      Without prejudice to any other rights under this Agreement, if any amount
      payable under this Agreement is not paid when due, the defaulting Party
      shall pay interest on a daily basis on such amount from the due date of
      payment (after as well as before judgment) at a rate equal to SIX PER
      CENT (6%) over the Agreed Rate.

15.   CONFIDENTIALITY AND ANNOUNCEMENTS

15.1  AGREED ANNOUNCEMENTS

      No Party shall, without the written consent of the other Party (which
      consent shall not be unreasonably withheld), issue or make any public
      announcement relating to, or disclose anything regarding, this Agreement.

15.2  LEGAL REQUIREMENTS

      (a)    If a Party is required to disclose anything in respect of this
             Agreement in order to comply with:

             (i)    applicable law; or

             (ii)   the requirements of any recognised stock exchange on which 
                    a Parties' or its Related Body Corporates' shares are 
                    listed;

             then the Parties shall agree on the form and substance of such
             disclosure and a copy of the same shall be furnished to the other
             Parties prior to publication or release.

      (b)    A Party will be deemed to have agreed to the terms of any
             disclosure if it has not objected to the form or substance of such
             release within ONE (1) Business Day of it being received by the
             Party. Each Party agrees to use its best endeavours to approve
             releases as soon as possible so that Parties are able to comply
             with statutory or stock exchange requirements.



                                      22.

<PAGE>   24


16.   ASSIGNMENT

      Neither Party may assign the rights under, or the benefit or the burden
      of, this Agreement.

17.   NOTICE

      A notice, demand, consent or authority given or made to a person:

      (a)    must be in writing;

      (b)    may be given or made by:

             (i)    delivering it to that person personally;

             (ii)   addressing it to that person and either leaving it at, or 
                    posting it to, the address of that person appearing in this
                    Agreement or any other address nominated by that person by
                    notice to the person giving the notice; or

             (iii)  sending a facsimile copy of the notice to the facsimile  
                    copier number nominated by that person by notice to the
                    person giving the notice; and

      (c)    will be deemed to be given or made:

             (i)    if by leaving it at the address of that person, when left 
                    at that address;

             (ii)   if by post, on the second Business Day after the date of 
                    posting (if posted to an address in the same country) or on 
                    the seventh Business Day after the date of posting (if 
                    posted to an address in another country);

             (iii)  if by facsimile, on receipt by the sender of a transmission 
                    control report from the despatching machine showing the 
                    relevant number of pages and the correct destination 
                    facsimile machine number and indicating that the 
                    transmission had been made without error,

             but if the result is that a notice would be taken to be given or
             made on a day which is not a Business Day in the place to which 
             the notice is sent or is later than 4.00pm (local time) it will be
             taken to have been duly given or made at the commencement of
             business on the next Business Day in that place.

18.   PROPER LAW

      This Agreement is governed by, and to be interpreted in accordance with,
      the laws of Western Australia and where applicable the laws of the
      Commonwealth of Australia.


                                      23.

<PAGE>   25


19.   JURISDICTION

      The Parties agree to submit to the jurisdiction of the courts of Western
      Australia and if applicable the Commonwealth of Australia.

20.   COUNTERPARTS

      This Agreement may be executed in any number of counterparts each of
      which is an original instrument and all of which constitute one and the
      same instrument.

21.   ENTIRE AGREEMENT

21.1  AGREEMENT CONSTITUTES ENTIRE AGREEMENT

      This Agreement constitutes the entire agreement between the Parties with
      respect to the subject matter of this Agreement and contains all of the
      representations, warranties, covenants and agreements of the Parties and
      supersedes all prior agreements and understandings in relation to the
      subject matter of the Agreement as at the date of this Agreement, other
      than the confidentiality agreement entered into by the Parties prior to
      execution of this Agreement which remains in force until Completion.

21.2  NO RELIANCE ON ORAL REPRESENTATIONS

      Each Party acknowledges that it has not relied on any oral statement,
      representation, undertaking, covenant or agreement made before the date
      of this Agreement relating to the subject matter of this Agreement and
      not contained in this Agreement.

22.   MORATORIUM NOT TO APPLY

      To the fullest extent permitted by law, the provisions of a statute which
      would, but for this clause:

      (a)    extend or postpone the date of payment of money; or

      (b)    abrogate, nullify, postpone or otherwise affect any condition;

      under this Agreement do not apply to limit or affect the terms of this 
      Agreement.

23.   SEVERANCE

      (a)    If any part of this Agreement is, or becomes, void or
             unenforceable, that part is, or will be, severed from this
             Agreement so that all parts that are not, or do not become, void
             or unenforceable remain in full force and effect and are
             unaffected by that severance.


                                      24.
<PAGE>   26

      (b)    If any provision of this Agreement, or the application thereof to
             any person or any circumstance, is invalid or unenforceable, a
             suitable and equitable provision shall be substituted therefor in
             order to carry out, so far as may be valid and enforceable, the
             intent and purpose of such invalid or unenforceable provision and
             the remainder of this Agreement and the application of such
             provision to other persons or circumstances shall not be affected
             by such invalidity or unenforceability, nor shall such invalidity
             or unenforceability affect the validity or enforceability of such
             provision, or the application thereof, in any other jurisdiction.

24.   WAIVERS

24.1  FAILURE OR DELAY IS NOT WAIVER

      Failure to exercise or delay in exercising any right, power or privilege
      by a Party does not operate as a waiver of that right, power or
      privilege.

24.2  PARTIAL EXERCISE DOES NOT PRECLUDE FURTHER EXERCISE

      A single or partial exercise of any right, power or privilege by a Party
      does not preclude:

      (a)    any other or further exercise of that right, power or privilege;
             or

      (b)    the exercise of any other right, power or privilege.

25.   VARIATION

      This Agreement may be varied only by agreement in writing signed by the
      Parties.

26.   FURTHER ASSURANCES

      Each Party must execute and do all acts and things necessary or desirable
      to implement and give full effect to the provisions and purpose of this
      Agreement.

27.   MERGER

      The rights and obligations of the Parties will not merge on the
      completion of any transaction contemplated by this Agreement. They will
      survive the execution and delivery of any assignment or other document
      entered into for the purpose of implementing any such transaction.


                                      25.
<PAGE>   27


28.   INTERPRETATION

28.1  REFERENCE TO A STATUTE

      A reference to a statute includes a regulation, by-law, requisition and
      order made under that statute and any amendment to or re-enactment of
      that statute, regulation, by-law, requisition or order for the time being
      in force.

28.2  JOINT AND SEVERAL COVENANTS

      If the Buyer comprises two or more persons, the covenants and agreements
      on their part bind and must be observed and performed by them jointly and
      each of them severally and may be enforced against any one or any two or
      more of them.

28.3  LAST DAY NOT A BUSINESS DAY

      When the day or last day for doing an act is not a Business Day in the
      place where that act is to be done, the day or last day for doing the act
      will be the next following Business Day in the place where that act is to
      be done.

28.4  HEADINGS

      Except in the Schedule, headings in this Agreement are for convenience
      and identification of clauses only and do not otherwise affect its
      interpretation.

28.5  REFERENCE TO OTHER DOCUMENT

      Subject to any contrary provision in this Agreement, a reference to any
      other deed, agreement, instrument or contract (including the Joint
      Venture Contracts and the Sales Contracts) includes a reference to that
      other deed, agreement, instrument or contract as amended, supplemented or
      varied from time to time.

28.6  REFERENCE TO A PARTY

      Unless contrary to the sense or context, a reference to a Party includes
      that Party's administrators, personal representatives, successors and
      assigns, and if the Buyer comprises two or more persons, administrators,
      personal representatives, successors and assigns of each of those
      persons.

28.7  SINGULAR, PLURAL AND GENDER

      Where applicable:

      (a)    words denoting the singular include the plural;

      (b)    words denoting the plural include the singular; and

      (c)    words denoting a gender include each gender.


                                      26.
<PAGE>   28

28.8  REFERENCE TO A PERSON AND A BODY CORPORATE

      Where applicable:

      (a)    a reference to a body corporate includes a natural person; and

      (b)    a reference to a person includes a body corporate.

28.9  PROFESSIONAL BODY

      A reference to a professional body includes a successor to or substitute
      for that body.

28.10 PARTIES IN INTEREST

      This Agreement shall inure to the benefit of and be binding upon the
      Parties and their respective successors and permitted assigns. Nothing in
      this Agreement, express or implied, is intended to confer upon any person
      other than the Buyer, the Seller or their respective successors or
      permitted assigns, any rights or remedies under or by reason of this
      Agreement.

EXECUTED BY THE PARTIES

THE COMMON SEAL of AMPOLEX          )
LIMITED ACN 000 113 217 is affixed  )                              [SEAL]
in accordance with its articles of  )
association in the presence of:     )

/s/ Dan P. Haworth                            /s/ Graeme K. Alexander
- ------------------------------------          ---------------------------------
Signature Director                            Signature Secretary*

Dan P. Haworth                                Graeme K. Alexander
- ------------------------------------          ---------------------------------
Print full name of signatory                  Print full name of signatory

*  Delete if not applicable


SIGNED for and on behalf of         )
APACHE ENERGY LIMITED               )
ACN 009 301 964 by                  )
LISA A FLOYD as duly authorised     )         /s/ Lisa A. Floyd
corporate representative            )         ---------------------------------
in the presence of:                 )         Lisa A Floyd



/s/ Eve A. Howell
- ------------------------------------
Witness



                                      27.
<PAGE>   29


                                  SCHEDULE ONE


1.    TITLES

      Exploration Permit WA-192-P 
      Exploration Permit EP 307 
      Exploration Permit EP 358 
      Exploration Permit TP/8 
      Production Licence TL/1 
      Production Licence TL/5 
      Production Licence TL/6 
      Pipeline Licence PL/12  
      Pipeline Licence PL/17  
      Pipeline Licence TPL/1  
      Pipeline Licence TPL/2  
      Pipeline Licence TPL/5  
      Pipeline Licence TPL/8  

2.    INTERESTS

      1% interest in the Assets.

3.    SPECIFIED ENCUMBRANCES

      1.     Charge No. 277793 registered on 24/01/1990 given by the Company
             pursuant to Section 16.3 of the Joint Operating Agreement for
             Exploration and Appraisal of WA-192-P and EP 307 dated 5 August
             1985;

      2.     Charge No. 277801 registered on 24/01/1990 given by the Company
             pursuant to Section 16.3 of the Joint Operating Agreement for
             Exploration and Appraisal of Production Licences dated 5 August
             1985;

      3.     Charge No. 277813 registered on 24/01/1990 given by the Company
             pursuant to Section 12.4 of an Approved Field Joint Operating
             Agreement (WA-192-P Development and Production) dated 5 August
             1985.


                                      28.
<PAGE>   30


                                  SCHEDULE TWO
                              SELLER'S WARRANTIES


1.    SHARES

1.1   The Seller is the registered holder and beneficial owner of the
      Shares and has power to transfer title to the Shares being the only
      shares issued in the capital of the Company.

1.2   The Shares have been validly issued, are fully paid and are free from all
      Encumbrances.

1.3   There are no restrictions known to the Seller on the transfer of the
      Shares, save that the approval of the board of directors of the Company
      may be required in order to register the transfers.

1.4   The Company has not granted to any person a right to subscribe for or 
      acquire or convert any security into any of the Company's unissued
      shares.

1.5   No person has any pre-emptive right with respect to any of the Shares.

1.6   The Company is not under an obligation to issue further shares.

1.7   There are no dividends declared by the Company which are not paid or 
      credited to a loan account of a shareholder of the Company.

2.    STATUS OF THE COMPANY

2.1   The copy of the Memorandum and Articles of Association of the
      Company initialled for identification by an officer of the Company and
      produced prior to executing this Agreement is a true copy and includes
      all amendments made up to the date of this Agreement.

2.2   No resolution to alter the Company's Memorandum or Articles of 
      Association as produced has been passed since the Effective Date.

2.3   The Company is not:

      (a)    wound up, no resolution for its winding up has been passed and no
             meeting of members or creditors has been convened for that
             purpose;

      (b)    the subject of a winding up application which has been made to a
             Court, and no event has occurred which would entitle any person to
             apply to a Court to wind up the Company;

      (c)    a party to a composition or arrangement with any of its creditors;


                                      29.
<PAGE>   31


      (d)    the recipient of a statutory demand under sections 459A-461 of the
             Corporations Law;

      (e)    in receivership and none of its assets is in the possession of or
             under the control of a mortgagee or chargee; or

      (f)    subject to administration under Part 5.3A of the Corporations Law.

      and the Seller is not aware of any facts or circumstances which would, or
      are likely to, result in any of the above.

2.4   The Company has not received from the Australian Securities Commission 
      any notice or warning of possible cancellation of registration of the
      Company.

3.    BALANCE SHEET

      The Balance Sheet, to the best of the knowledge of the Seller and subject
      to the notes to the accounts and other matters noted:

      (a)    presents a true and fair view of the financial position of the
             Company as at the Effective Date; and

      (b)    has been prepared and audited in accordance with the relevant
             accounting standards and generally accepted accounting principles
             consistently applied.

4.    TITLE TO ASSETS

      The Company has good title to the Assets.

5.    POWER OF ATTORNEY

      The Company has not granted any power of attorney which will be effective
      at or after Completion.

6.    PROCEEDINGS PENDING

6.1   The Company is not engaged in any litigation, arbitration, prosecution or
      other legal proceedings, or any proceedings or hearings before any
      statutory or governmental body, department, board or agency.

6.2   To the Seller's best knowledge and belief there are no facts which are 
      likely to give rise to any litigation, arbitration, prosecution or other
      legal proceedings, or any proceedings or hearings before any statutory or
      governmental body, department, board or agency.

7.    BUSINESS SINCE EFFECTIVE DATE

      Since the Effective Date:


                                      30.
<PAGE>   32

      (a)    the Company has carried on business and dealt with its property
             and assets only as a consequence of trading in the ordinary course
             of business, save as disclosed by the Seller;

      (b)    no alteration has been made to the share capital of the Company;

      (c)    the Company has not declared or paid any dividend or any amount
             which may be deemed to be a dividend or passed any special
             resolution;

      (d)    the Company has not granted any Encumbrance over or any part of
             the Assets other than under the Joint Venture Contracts and the
             Specified Encumbrances; and

      (e)    the Company has no employees.

8.    CONTRACTS

8.1   To the best of the Seller's knowledge, all agreements binding on the
      Company not entered into in the ordinary course of Business of the
      Company have been disclosed to the Buyer.

8.2   To the best of the Seller's knowledge, the Company is not party to any 
      agreement which may be terminated by any other party by reason of a
      change in the ownership of the Shares by reason of the change being
      subject to the consent of the other party, which consent has not been
      obtained.

8.3   All material agreements entered into by the Company have been executed in
      accordance with the Company's Articles of Association, are within the
      authority of the Company and are valid and binding on the Company and, to
      the best of the Seller's knowledge and belief, on the other parties to
      those agreements.

9.    SUBSIDIARIES

      The Company has no subsidiaries at the Completion Date.

10.   AUTHORITY

10.1  The Seller is duly incorporated with limited liability and validly 
      existing under the laws of its country of incorporation.

10.2  The documents which contain or establish the Sellers' constitution
      incorporate provisions which authorise, and all necessary corporate
      action has been taken to authorise, the Seller to execute and deliver
      this Agreement and this Agreement does, and the further documents to be
      executed by the Seller hereunder will, constitute legal, valid and
      binding obligations of the Seller enforceable against them in accordance
      with their respective terms.


                                      31.
<PAGE>   33


10.3  The signing and delivery of this Agreement and the performance of the 
      transaction contemplated by this Agreement will not contravene or
      constitute a default under a provision contained in any agreement,
      instrument, law, judgment, order, licence, permit or consent by which the
      Seller is bound.

10.4  The Seller has not incurred any obligation or liability, contingent or 
      otherwise, for brokers' or finders' fees in respect of the transaction
      under this Agreement for which the Buyer will have any obligation.

11.   COMPLETENESS OF INFORMATION

      The Seller has provided to the Buyer all information within its knowledge
      which could reasonably be considered to be material in relation to the
      Company, the Shares and the Assets or to their value.

12.   ASSETS

12.1  The Company's legal and beneficial ownership of the Assets is as set out 
      in Schedule One, free and clear of all Encumbrances, other than as there
      set out or in the Joint Venture Contracts, Specified Encumbrances, the
      terms of grant of the Titles or under the Petroleum Legislation.

12.2  The Joint Venture Contracts are to the best of the knowledge and belief 
      of the Seller, a complete list of all material agreements constituting or
      regulating the interests of the Seller in the Titles.

12.3  The Seller has not received any notice of any material breach of its 
      obligations under the Joint Venture Contracts or the Sale Contracts.

12.4  The Seller is not in material default under the Joint Venture Contracts 
      or the Sale Contracts.

13.   OPERATIONS

      To the best of the knowledge and belief of the Seller:

      (a)    all material conditions and obligations to which the Assets are
             subject have been complied with and performed; and

      (b)    all Petroleum operations with respect to the Assets have been and
             are now conducted in accordance with applicable laws and good
             oilfield practice.

14.   DEFAULT OF OTHER VENTURERS

      The Company has not in the last TWELVE (12) months received any notice of
      default in respect of any other party to the Joint Venture Contracts.


                                      32.
<PAGE>   34


15.   COMPLIANCE

      Except in relation to Tax matters:

      (a)    to the best knowledge and belief of the Seller there are no
             material notices of any public or statutory authority outstanding
             against the Company; and.

      (b)    the Company has complied in all material respects with the
             provisions of all laws and regulations and all orders, notices,
             awards and determinations made by any statutory or other competent
             authority in any way relating to or binding on the Company or the
             Assets.


                                      33.
<PAGE>   35

                                 SCHEDULE THREE
                               BUYER'S WARRANTIES


      WARRANTIES OF THE BUYER

      (a)    The Buyer is duly incorporated with limited liability and validly
             existing under the laws of its country of incorporation.

      (b)    The signing and delivery of this Agreement and the performance of
             the transactions contemplated by this Agreement will not
             contravene or constitute a default under the provision contained
             in any agreement, instrument, law, judgment, order, license,
             permit or consent by which the Buyer is bound.

      (c)    The Buyer has not incurred any obligation or liability, contingent
             or otherwise, for brokers' or finders' fees in respect of the
             transaction herein provided for which the Sellers will have any
             obligation.

      (d)    The Shares are being purchased by the Buyer for its own account
             for investment and not for purpose of, or with a view to, the
             resale or distribution thereof.

      (e)    The documents which contain or establish the Buyer's constitution
             incorporate provisions which authorise, and all necessary
             corporate action has been taken to authorise, the Buyer to execute
             and deliver this Agreement and this Agreement does, and the
             further documents to be executed by the Buyer hereunder will,
             constitute legal, valid and binding obligations of the Buyer
             enforceable against them in accordance with their respective
             terms.

      (f)    The signing and delivery of this Agreement and the performance of
             the transaction contemplated by this Agreement will not contravene
             or constitute a default under a provision contained in any
             agreement, instrument, law, judgment, order, licence, permit or
             consent by which the Buyer is bound.

      (g)    The Buyer, on the Completion Date, will have sufficient funds to
             effect Completion and all other transactions contemplated by this
             Agreement.

      (h)    Except as specifically set forth in this Agreement, no consent,
             approval, waiver or authorisation is required to be obtained by
             the Buyer and no notice or filing is required to be given by the
             Buyer with any federal, state, local or other governmental
             authority in connection with the execution, delivery and
             performance by the Buyer of this Agreement.


                                      34.

<PAGE>   36

      (i)    The Buyer is not:

             (i)    wound up, no resolution for its winding up has been passed 
                    and no meeting of members or creditors has been convened 
                    for that purpose;

             (ii)   the subject of a winding up application which has been made
                    to a Court, and no event has occurred which would entitle 
                    any person to apply to a Court to wind up the Buyer;

             (iii)  a party to a composition or arrangement with any of its 
                    creditors;

             (iv)   the recipient of a statutory demand under sections 459A-461
                    of the Corporations Law;

             (v)    in receivership and none of its assets is in the possession
                    of or under the control of a mortgagee or chargee; or

             (vi)   subject to administration under Part 5.3A of the 
                    Corporations Law.

      (j)    The Buyer has not received from the Australian Securities
             Commission any notice or warning of possible cancellation of
             registration of the Company.

      (k)    The Buyer is not engaged in any litigation, arbitration,
             prosecution or other legal proceedings, or any proceedings or
             hearings before any statutory or governmental body, department,
             board or agency which would be likely to prejudice the Buyer's
             performance of its obligations under this Agreement.

      (l)    There are no facts known to the Buyer which are likely to give
             rise to any litigation, arbitration, prosecution or other legal
             proceedings, or any proceedings or hearings before any statutory
             or governmental body, department, board or agency involving the
             Buyer which would be likely to prejudice the Buyer's performance
             of its obligations under this Agreement.


                                      35.
<PAGE>   37

                                 SCHEDULE FOUR
                                    ACCOUNTS


1.    PREPARATION

      (a)    The initial working capital statement at 30 June 1997 which is
             based on the Balance Sheet is attached as Schedule Eight.

      (b)    The Seller shall procure that the Company prepares a statement of
             Working Capital of the Company taking into account the adjustments
             under Part 2 of this Schedule (WORKING CAPITAL STATEMENT) not less
             than SEVEN (7) days prior to the Completion Date;

      (c)    The Seller shall prepare the following statements of account:

             (i)    a profit and loss account in respect of the Assets
                    for the period from the Effective Date to the end of the
                    month immediately prior to the Completion Date (ADJUSTMENT
                    DATE) (PROFIT AND LOSS ACCOUNT); and

             (ii)   a statement of capital expenditure in respect of
                    the Assets from the Effective Date to the Adjustment Date
                    (CAPITAL STATEMENT).

      (d)    All amounts in US dollars are to be converted to Australian
             dollars based on the transaction settlement date converted at the
             Wholesale Market Hedge rate published in the Australian Financial
             Review.

      (e)    The Working Capital Statement, the Profit & Loss Account and the
             Capital Statement are referred to as the ACCOUNTS.

2.    WORKING CAPITAL

      (a)    The working capital figure in the Working Capital Statement will
             take into account the matters set out in this Part in respect of
             the Assets, the Joint Venture Documents and the hydrocarbons
             produced from the Assets.

      (b)    For the purpose of the Working Capital Statement, the working
             capital figure will be based on, but not limited to, the initial
             items taken from the initial Working Capital Statement in Schedule
             Eight, but will be varied, to the extent that any variation is
             necessary, to take into account:

             (i)    the purchase price of the hydrocarbons on hand as at 00:01 
                    on the Effective Date determined in accordance with
                    paragraphs (c) and (d) (such amounts to be treated as a
                    current asset);


                                      36.
<PAGE>   38

             (ii)   the amount of any calls payable in respect of the Assets 
                    after 00:01 on the Effective Date, which were paid on or
                    before the Effective Date (such amounts to be treated as a 
                    current asset);

             (iii)  the amount of any calls payable in respect of the Assets on
                    or before 00:01 on the Effective Date, which were unpaid on
                    or before the Effective Date (such amounts to be treated as
                    a current liability);

             (iv)   any other outstanding amount by or to the Company in 
                    respect of the Assets that relate to operations of the
                    Company on or before the Effective Date; and

             (v)    any over contribution or under contribution in respect of 
                    the Company recorded in the books of the Operator at the
                    Effective Date.

      (c)    The Company's interest in the stock of hydrocarbons attributable
             to the Assets on hand as at 00:01 on the Effective Date comprises:

             (i)    liquids downstream of the wellheads as estimated by the 
                    Operator; and

             (ii)   gas downsteam of the low temperature separation plant as 
                    estimated by the Operator.

      (d)    The purchase price of the hydrocarbons on hand will be:

             (i)    for all of such hydrocarbons, the actual proceeds of sale; 
                    less

             (ii)   for all of such hydrocarbons, actual or (where no actual is
                    available) estimated transportation, wharfage and royalty 
                    costs incurred through to the point of sale, where 
                    estimates are based on the average per barrel implied from
                    actual payments over the preceding three months.

3.    PROFIT & LOSS ACCOUNT

      (a)    The Profit and Loss Account shall take into account:

             (i)    the amount of operating costs included in any calls paid in
                    respect of the Assets from the Effective Date to the
                    Adjustment Date and the costs of insurances under Clause 
                    8.3 (such amounts to be treated as expenses); and

             (ii)   the amount of any cash received or entitled to be received 
                    in respect of sales of hydrocarbons made pursuant to the 
                    Sales Contracts and invoiced in the period from the 
                    Effective Date to the Adjustment Date and any other income 
                    received in respect of the Assets (such amounts to be 
                    treated as revenue).


                                      37.
<PAGE>   39


      (b)    In this Part, if the total of revenue exceeds the total of
             expenses, then the amount of the difference shall be charged to
             the Seller Account, otherwise the amount of the difference shall
             be charged to the Buyer Account.

4.    CAPITAL STATEMENT

      (a)    The Capital Statement shall take into account the amount of any
             capital cost or receipt comprised or adjusted for in any call paid
             or received in respect of the Assets from the Effective Date to
             the Adjustment Date (such amounts to be treated as property, plant
             and equipment).

      (b)    In this Part, if the total of capital costs under paragraph (a)
             exceeds the total of capital receipts, then the amount of the
             difference shall be charged to the Buyer Account, otherwise the
             amount of the difference shall be charged to the Seller Account.

5.    PROCEDURE TO AGREE ACCOUNTS

      (a)    Not less than SEVEN (7) Business Days prior to the projected
             Completion Date, the Seller agrees to submit the Accounts to the
             Buyer. The Seller will provide supporting documentation.

      (b)    Within FOUR (4) Business Days of the date on which the Seller
             provides the Accounts (or such shorter time as the parties agree),
             the Buyer agrees to advise the Seller in writing as to any amounts
             it does not agree to, including its reasons.

      (c)    The Parties will in good faith seek to reach agreement without
             delay on any amounts not agreed to between them.

      (d)    If no notice is given by the Buyer under paragraph (b) of this
             Part, then the Accounts will be treated as the Accounts for the
             purposes of determining the amounts to be paid or allowed at
             Completion.

      (e)    If a notice is given by any Party under paragraph (b) of this Part
             and the Parties do not resolve the matter within THREE (3)
             Business Days prior to Completion, then the Parties will pay at
             Completion the amounts in the Buyer Account and the Seller Account
             not in dispute under clause 4 of the Agreement.

      (f)    If any amount is not agreed nor paid or allowed at Completion,
             then either Party may give notice to the other that the matter be
             referred to an Independent Accountant. The notice must suggest a
             person to be the Independent Accountant and process set out in
             Schedule 6 must be followed.


                                      38.

<PAGE>   40

      (g)    If a reference is made to the Independent Accountant under
             paragraph (f) of this Part, the terms of reference must be to
             resolve the matters in dispute in accordance with the principles
             set out in Parts 1, 2, 3 and 4 of this Schedule as soon as
             possible. The Buyer and Seller must co-operate and make
             information available as requested by the Independent Accountant.
             The Buyer and the Seller must ensure that the Company promptly
             makes available such information as the Independent Accountant may
             request in relation to the matters in dispute. All correspondence
             between the Independent Accountant and any Party must be promptly
             copied to the other Party.

      (h)    The Independent Accountant must issue a certificate as to his
             determination of the matters referred to him and of the Accounts,
             adjusted (if necessary) to take account of his determinations. The
             Buyer and Seller agree that in carrying out this role, the
             Independent Accountant acts as expert and not arbitrator and that,
             in the absence of fraud or mistake or manifest error, the
             certificate issues by the Independent Accountant will be final and
             binding on them.

      (i)    The Buyer and the Seller will bear equally the costs of the
             Independent Accountant.

6.    POST COMPLETION ADJUSTMENTS FOR PERIOD BETWEEN ADJUSTMENT DATE AND 
      COMPLETION

      (a)    Within THIRTY (30) days after the end of the month in which
             Completion occurs the Seller will prepare the Accounts and submit
             them to the Buyer, in each case made up to the Completion Date.

      (b)    The Parties will follow the procedures set out in Part 5 of this
             Schedule to determine the Buyer Account and the Seller Account as
             at the Completion Date.

      (c)    Any difference between the Buyer Account and the Seller Account at
             the Adjustment Date and at the Completion Date will be paid to the
             Party entitled by the other Party within FIVE (5) Business Days of
             determination of those Accounts.


                                      39.
<PAGE>   41

                                 SCHEDULE FIVE

JOINT VENTURE CONTRACTS

Approved Field Joint Operating Agreement (WA-192-P Development and Production)
("Production JOA") dated 5 August 1985 between Bond Corporation Pty Ltd, Texas
Eastern Australia, Inc., Reading & Bates Australia Petroleum Co., Petro Energy
Limited, Pontoon Oil & Minerals NL, Pelsart Oil NL, Swan Television & Radio
Broadcasters Limited and New World Oil & Developments Pty Ltd;

Joint Operating Agreement for Exploration and Appraisal of WA-192-P and EP307
("Permit Exploration JOA") dated 5 August 1985 between Bond Corporation Pty
Ltd, Texas Eastern Australia, Inc., Reading & Bates Australia Petroleum Co.,
Petro Energy Limited, Pontoon Oil & Minerals NL, Pelsart Oil NL, Swan
Television & Radio Broadcasters Limited and New World Oil & Developments Pty
Ltd;

Joint Operating Agreement for Exploration and Appraisal of Production Licence
("Production Licence Exploration JOA") dated 5 August 1985 between Bond
Corporation Pty Ltd, Texas Eastern Australia, Inc., Reading & Bates Australia
Petroleum Co., Petro Energy Limited, Pontoon Oil & Minerals NL, Pelsart Oil NL,
Swan Television & Radio Broadcasters Limited and New World Oil & Developments
Pty Ltd;

Production - Exploration Co-Ordination Deed (WA-192-P and Production Licence)
dated 5 August 1985 between Bond Corporation Pty Ltd, Texas Eastern Australia,
Inc., Reading & Bates Australia Petroleum Co., Petro Energy Limited, Pontoon
Oil & Minerals NL, Pelsart Oil NL, Swan Television & Radio Broadcasters Limited
and New World Oil & Developments Pty Ltd;

Seller's Representative Agreement WA-192-P New Production Licence - Produced
Petroleum dated 5 August 1985 between Bond Corporation Pty Ltd, Texas Eastern
Australia, Inc., Reading & Bates Australia Petroleum Co., Petro Energy Limited,
Pontoon Oil & Minerals NL, Pelsart Oil NL, Swan Television & Radio Broadcasters
Limited and New World Oil & Developments Pty Ltd;

Deed of Cross Charge given by the Company (No. 277793) pursuant to Permit
Exploration JOA created 18 January 1990 and other charges given by New World
Oil & Developments Pty Ltd, Hardy Petroleum Limited, Marubeni Oil Australia Pty
Ltd, Novus (Harriet) Limited, Ampolex (Western Australia), Inc., Apache
Northwest Pty Ltd and Kufpec Australia Pty Ltd;

Deed of Cross Charge given by the Company (No. 277801) pursuant to Production
Licence Exploration JOA created 18 January 1990 and other charges given by New
World Oil & Developments Pty Ltd, Hardy Petroleum Limited, Marubeni Oil
Australia Pty Ltd, Novus (Harriet) Limited, Ampolex (Western Australia), Inc.,
Apache Northwest Pty Ltd and Kufpec Australia Pty Ltd;


                                      40.
<PAGE>   42

Deed of Cross Charge given by the Company (No. 277813) pursuant to Production
JOA created 18 January 1990 and other charges given by New World Oil &
Developments Pty Ltd, Hardy Petroleum Limited, Marubeni Oil Australia Pty Ltd,
Novus (Harriet) Limited, Ampolex (Western Australia), Inc., Apache Northwest
Pty Ltd and Kufpec Australia Pty Ltd;

Harriet Joint Venture and East Spar Joint Venture Access Agreement (Varanus
Island) dated 12 December 1996 between Ampolex (Western Australia) Inc., the
Company, Apache Northwest Pty Ltd, Hardy Petroleum Limited, Kufpec Australia
Pty Ltd, Tap (Harriet) Pty Ltd, Novus UK (Harriet) Limited, New World Oil &
Developments Pty Ltd, Ampolex (A.O.E.) Limited, Apache Oil Australia Pty Ltd,
Santos (BOL) Pty Ltd, WMC Resources Ltd and Apache Energy Limited;

Assignment, Farm-in/Farm-out, Assumption, novation and covenant documentation
registered as dealings against the Titles, or any predecessor title thereof in
the Registers maintained under the Petroleum Legislation.

SALES CONTRACTS

GAS

Heads of Agreement for the Purchase of Natural Gas from the Harriet Area dated
12 December 1990 between SECWA, Hadson Australia Development Pty Ltd, Hardy
Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni Oil Australia Pty Ltd,
Petro Energy Limited, Ampolex (Western Australia), Inc., the Company, Swedish
Exploration Consortium AB and New World Oil & Developments Pty Ltd;

Heads of Agreement for Gas Supply and Purchase (Normandy Power) dated 24
October 1994 between Normandy Power Pty Ltd, Ampolex (Western Australia), Inc.,
the Company, Hadson Australia Development Pty Ltd, Hardy Petroleum Limited,
Kufpec Australia Pty Ltd, Marubeni Oil Australia Pty Ltd, Monument Oil
(Australia) Limited, New World Oil & Developments Pty Ltd and Petro Energy
Limited;

Gas Supply and Purchase Agreement dated 21 July 1995 between Apache Northwest
Pty Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni Oil
Australia Pty Ltd, Monument Oil (Australia) Limited, New World Oil &
Developments Pty Ltd, Ampolex (Western Australia), Inc., the Company, Doral
Resources NL, Pan Pacific Petroleum NL, Haoma Petroleum Pty Ltd, Strata
Petroleum Pty Ltd, Carnarvon Oil & Gas NL and Roy Antony Radford;

Deed of Assumption - Apache Gas Sale Agreement dated 19 December 1995 between
Doral Resources NL, Haoma Petroleum Pty Ltd, Strata Petroleum Pty Ltd, Sagasco
South East Inc., Boral Energy Petroleum Limited, Boral Energy Amadeus NL, Pan
Pacific Petroleum NL, Carnarvon Oil & Gas NL, Roy Antony Radford, Apache
Northwest Pty Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni
Oil Australia Pty Ltd, Monument Oil (Australia) Limited, New World Oil &
Developments Pty Ltd, Ampolex (Western Australia), Inc. and the Company;


                                      41.
<PAGE>   43

Interim Gas Agreement dated on or about 19 February 1996 between Ampolex
(Western Australia), Inc., the Company, Apache North West Pty Ltd, Hardy
Petroleum Limited, Kufpec Australia Pty Limited, Marubeni Oil Australia Pty
Limited, Novus UK (Harriet) Limited, New World Oil & Developments Pty Limited,
Ampolex (A.O.E.) Limited, Apache Oil Australia Pty Limited, Parker & Parsley
Australasia Limited and Western Mining Corporation Limited;

Gas Supply and Purchase Agreement (Alcoa) dated 5 June 1996 between Alcoa of
Australia Limited, Ampolex (Western Australia), Inc., the Company, Apache North
West Pty Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd, Marubeni Oil
Australia Pty Ltd, New World Oil & Developments Pty Ltd and Novus UK (Harriet)
Limited;

Wiluna Gas Sales Agreement dated 8 April 1997 between Apache Northwest Pty Ltd,
Hardy Petroleum Limited, Kufpec Australia Pty Ltd, TAP (Harriet) Pty Ltd, Novus
UK (Harriet) Limited, New World Oil & Developments Pty Limited, Ampolex
(Western Australia), Inc., the Company and Wiluna Gold Pty Limited;

Gas Sale Agreement (Boral) dated 17 June 1997 between Boral Gas (WA) Pty
Limited, Ampolex (Western Australia), Inc., the Company, Apache Northwest Pty
Ltd, Hardy Petroleum Limited, Kufpec Australia Pty Ltd, TAP (Harriet) Pty Ltd,
Novus UK (Harriet) Limited and New World Oil & Developments Pty Ltd.

CRUDE

Harriet Oilfield Royalty Agreement dated 20 September 1989 between Jeffrey Carr
(Minister for Administration of PSLA (W.A.)), Bond Corporation Pty Ltd, Hadson
Australia Development Pty Ltd, Varanus Pty Ltd, TEA Australia Inc., Petro
Energy Limited and New World Oil & Developments Pty Ltd;

Terms and Conditions of Sale of Varanus Crude dated 18 December 1996 between
Ampolex Varanus Pty Limited and Glencore International AG.


                                      42.
<PAGE>   44

                                  SCHEDULE SIX
                           PROCEDURES FOR INDEPENDENT
                            ACCOUNTANT DETERMINATION


1.    REFERRALS TO EXPERT

      Wherever in this Agreement any matter is to be referred to the
      Independent Accountant, then the terms of this Schedule shall apply.

2.    APPOINTMENT

      The procedure for appointing the Independent Accountant is as follows:

2.1   The disputing Party must give written notice including details of the 
      matter to be resolved by the Independent Accountant to the other Party.

2.2   If the matter is not resolved within FOURTEEN (14) days from the date of 
      the notice, the Parties shall agree on a single accountant to determine
      the dispute or, if no agreement is reached within FIVE (5) Business Days,
      a chartered accountant nominated by the President of the Institute of
      Chartered Accountants in Australia being a person who is not a partner,
      consultant or employee of the Buyer's accountants or the Seller's
      accountants and at which time is not or which firm for he or she works is
      not retained by the Buyer, the Seller or any of their Related Bodies
      Corporate in any capacity whatsoever.

2.3   DUTY OF DISCLOSURE

      Any person appointed as the Independent Accountant shall fully disclose
      any interest which may conflict with the appointment before accepting
      such appointment and, with the agreement of both Parties, shall be
      entitled to act as such expert, notwithstanding that he or she has, or
      may have, some interest which conflicts with such appointment.

2.4   POWERS AND DUTIES

      An Independent Accountant shall, within TEN (10) days of his or her
      acceptance of the appointment, fix a reasonable time and place for
      receiving submissions or information from the Parties or any other
      persons that he or she may think fit and may make further enquiries and
      require such other evidence as he or she considers necessary and shall
      determine the matter with all due diligence.

2.5   NOT ARBITRATOR

      The Independent Accountant shall not be an arbitrator but shall give his
      or her decision as an expert and the provisions of the Commercial
      Arbitration Act 1985 shall not apply to the expert, the determination or
      the determination procedure.


                                      43.
<PAGE>   45



2.6   DETERMINATION BINDING

      The Independent Accountant's determination shall be final and binding
      upon the Parties except for fraud, mistake or manifest error.

2.7   COSTS

      Each Party shall bear the costs and expenses of any consultants,
      witnesses and employees retained by it in connection with the matter, but
      the costs and expenses of the Independent Accountant shall be apportioned
      equally between the Parties.

2.8   REMOVAL OF INDEPENDENT ACCOUNTANT

      If the Independent Accountant has not made a determination within SIXTY
      (60) days of his appointment, either Party may, by notice, terminate such
      appointment.

2.9   APPOINTMENT OF REPLACEMENT

      In the event of such termination, a new Independent Accountant shall be
      appointed within TEN (10) days and the matter determined in accordance
      with this Schedule.

2.10  CONTINUED PERFORMANCE OF OBLIGATIONS

      The referral of a matter to the Independent Accountant shall not affect
      the obligations of the Parties to perform or pay any amount otherwise due
      in accordance with the terms and conditions of the Agreement.


                                      44.

<PAGE>   46


                                 SCHEDULE SEVEN
               SPECIAL PURPOSE FINANCIAL REPORT OF THE COMPANY AS
                                AT 30 JUNE 1997











                                   [OMITTED]




                                      45.

<PAGE>   47




                                 SCHEDULE EIGHT
                           WORKING CAPITAL STATEMENT











                                   [OMITTED]






                                      46.

<PAGE>   1

                                                                    EXHIBIT 99.1

                                [Press Release]
                              [Apache Letterhead]

CONTACTS:

(MEDIA):     JOHN KELSO               (713) 296-6155
(INVESTOR):  MELISSA REYNOLDS         (713) 296-6153

(WEB SITE):  WWW.APACHECORP.COM

                                                           FOR IMMEDIATE RELEASE

             APACHE TO ACQUIRE AUSTRALIAN PROPERTIES AND FACILITIES
                          FROM MOBIL FOR $310 MILLION


        Houston (October 8, 1997) -- Apache Corporation (NYSE: APA) today 
announced that it has entered into an agreement with a subsidiary of Mobil
Corporation under which Apache will acquire three companies that own interests
in certain oil and gas properties and production facilities offshore Western
Australia for approximately $310 million in cash ($425 million Australian),
effective July 1, 1997.  The companies are currently owned by Mobil's wholly
owned Ampolex Group. The transaction is subject to government approvals and is
expected to close in mid-November.
        
        Of the total purchase price, approximately $216 million (A$296 million)
is for certain oil and gas properties that contain net proved reserves of an
estimated 41.2 million barrels of oil equivalent (MMboe).  Approximately $85
million (A$116 million) of the purchase price is for existing gathering,
transportation and marketing facilities.  Apache's cost for proved reserves
only is $5.24 per barrel of oil equivalent (A$7.18 per barrel).  An additional
7.4 MMboe of probable reserves have been identified.  The remaining $9 million
(A$13 million) represents the aggregate working capital of the three companies.
The acquisition will be debt financed (within Apache's targeted leverage
ratios) and additive to both earnings and cash flow per share.

        Apache operates all of the properties to be acquired.  The transaction
will increase Apache's interest to 47.5 percent from 22.5 percent in the
Carnarvon Basin's Harriet area, which includes the Varanus Island pipeline,
processing and production complex and eight existing oil and gas fields.  It
also raises the company's interest in the nearby East Spar field, which
produces through the Varanus Island facilities, to 55 percent from 20 percent.

                                     -more-

<PAGE>   2
        Average daily production net to the acquired interests in 1998 is 
projected at 4,250 barrels of liquid hydrocarbons and 38 million cubic feet
(MMcf) of gas. Approximately 80 percent of the gas production is under
long-term, take-or-pay contracts.  By the year 2000, gas volumes under existing
take-or-pay contracts are scheduled to reach 60 MMcf per day.
        
        Apache President and Chief Operating Officer G. Steven Farris said,
"This transaction culminates a 20-month pursuit to solidify Apache's position
in the Carnarvon Basin.  The acquisition underscores our commitment to Western
Australia as a core operating area."

        Farris likened the basin to the Gulf of Mexico in the 1950s.  "It is
roughly the size of the Gulf of Mexico but significantly under-explored with
tremendous potential," he said.  "The 255,000 net acres to be acquired include
10 prospects scheduled for drilling by year-end 1998, and a recent 3-D seismic
survey is already generating new exploratory leads in proximity to our
strategically located Varanus Island complex," Farris said.

        Apache Corporation is a large oil and gas independent with operations
in North America, Egypt, Western Australia, Poland, People's Republic of China,
Indonesia and Cote d'Ivoire.  The company's shares are traded on the New York
and Chicago stock exchanges.

                                     -end-


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