EXHIBIT 2.2

                  DATED 11 JANUARY 2003


                  (1) BP EXPLORATION OPERATING COMPANY LIMITED

                  (2) APACHE NORTH SEA LIMITED



                           SALE AND PURCHASE AGREEMENT
                IN RESPECT OF CERTAIN INTERESTS IN UNITED KINGDOM
                 CONTINENTAL SHELF PETROLEUM PRODUCTION LICENCES




                               CMS CAMERON MCKENNA
                                   MITRE HOUSE
                              160 ALDERSGATE STREET
                                 LONDON EC1A 4DD

                              T +44(0)20 7367 3000
                              F +44(0)20 7367 2000

                                TABLE OF CONTENTS


                                                                            
1.    Definitions..........................................................      1
2.    Sale and Purchase of the Interests...................................      9
3.    Consideration........................................................      9
4.    Interim Period.......................................................     15
5.    Completion...........................................................     19
6.    Indemnities..........................................................     21
7.    Warranties...........................................................     23
8.    Ongoing obligations and liabilities..................................     30
9.    Confidentiality and Announcements....................................     31
10.   Notices..............................................................     33
11.   Costs and Expenses...................................................     34
12.   Taxation.............................................................     35
13.   Variation............................................................     42
14.   Assignment...........................................................     42
15.   Further Assurance....................................................     42
16.   General..............................................................     43
17.   Rights of Third Parties..............................................     43
18.   Governing Law........................................................     44

Schedule 1  Interests......................................................     45


Schedule 2  Allocation of Consideration....................................     59


Schedule 3  Working Capital................................................     60


Schedule 4  Interim and Final Completion Statement Formats.................     64


Schedule 5  Employees......................................................     65


Schedule 6  Pensions.......................................................     70




THIS AGREEMENT is made the 11th day of January 2003

BETWEEN

(1)      BP EXPLORATION OPERATING COMPANY LIMITED, a company incorporated in
         England (registered number 00305943) whose registered office is at
         Britannic House, 1 Finsbury Circus, London EC2M 7BA, England ("BPEOC");
         and

(2)      APACHE NORTH SEA LIMITED, a company incorporated in England (registered
         number 04614761) whose registered office is at Level 1, Exchange House,
         Primrose Street, London EC2A 2HS, England ("PURCHASER").


WHEREAS Seller wishes to sell and Purchaser wishes to buy the Interests on the
terms and conditions set out herein.


NOW THEREFORE IT IS HEREBY AGREED as follows:


1.       DEFINITIONS

1.1      In this Agreement (including the recital and Schedules hereto), the
         following expressions shall, except where the context otherwise
         requires, have the following respective meanings:

         "ADJUSTMENT": means any or all (as the context may require) of the
         Working Capital Adjustment, the Cash Calls Adjustment, the NPR
         Adjustment, the Petroleum Sales Adjustment and the Interim Period
         Adjustment;

         "ADJUSTMENT CLAUSES":  has the meaning given in clause 3.3;

         "AFE": means an authorisation for expenditure pursuant to an agreement
         relating to the Interests;

         "AFFILIATE": means in relation to any Party, a subsidiary or a holding
         company of that Party and includes the ultimate holding company of that
         Party and any subsidiary of that holding company and for the purposes
         of this definition "holding company" and "subsidiary" shall be
         construed in accordance with section 736 of the Companies Act 1985;

         "AGREED RATE":  means one percentage point above LIBOR;

         "BENEFITS":  has the meaning given in clause 6.2;


         "BLOCK": means a licence block on the United Kingdom Continental Shelf;

         "BUSINESS DAY": means a day (other than a Saturday, a Sunday or a bank
         or public holiday) on which banks are or, as the context may require,
         were generally open for business in England;


                                      -1-

         "CASH CALLS ADJUSTMENT":  has the meaning given in clause 3.5;

         "CHARGEABLE PERIOD": means a period of six months ending at the end of
         June or December;

         "COMPLETION": means the completion of the sale and purchase of the
         Interests in accordance with the provisions of this Agreement;

         "COMPLETION DOCUMENTS": means those documents referred to in Schedule 1
         Parts 1(g) and 2(g);

         "COMPLETION DATE":  means the date on which Completion takes place;

         "CONDENSATE": means a mixture of hydrocarbons of primarily C5+
         molecular weight which is produced from the processing of Raw Gas at
         the Terminal;

         "CONDITIONS PRECEDENT": means those conditions precedent listed in
         Schedule 1 Parts 1(f) and 2(f);

         "CONSIDERATION":  has the meaning given in clause 3.1;

         "CT": means Corporation Tax as charged under the Income and Corporation
         Taxes Act 1988 including, for the avoidance of doubt, the supplementary
         charge of 10% on the profits from United Kingdom and United Kingdom
         Continental Shelf oil and gas production (the "Supplementary Charge");

         "DATA": means in respect of the Interests all files, memoranda,
         reports, interpretations, documents and other data in the possession,
         custody or control of Seller (excluding Traded Data) relating directly
         to the Interests (and forming part of the property jointly owned by the
         Seller (or its Affiliates) and the other parties to the JOAs in
         accordance with the terms of such JOAs) whether in hard copy or in
         original form (where available) including geoscientific, seismic and
         engineering data and logs, but excluding internal memoranda, reports,
         interpretations and documents created for Seller's (or its Affiliates')
         own use and not forming part of the Interests;

         "DECOMMISSIONING LIABILITIES": means any claims, costs, charges,
         expenses, liabilities or obligations incurred in relation to
         decommissioning and/or removing and making safe all of the property
         related to the Interests (including but not limited to platforms,
         pipelines, plant, machinery, wells, facilities and all other offshore
         and onshore installations and structures) whether such liabilities are
         incurred under or pursuant to any of the Licensed Interest Documents or
         under statutory, common law or other obligation and including, without
         limitation, any residual liability for anticipated and/or necessary
         continuing insurance, maintenance and monitoring costs;

         "DISCLOSURE LETTER": means the letter of even date herewith delivered
         to Purchaser by Seller which sets out certain disclosures against the
         Warranties;

         "DOLLARS" or "$": means the lawful currency of the United States of
         America;


                                      -2-

         "DRY GAS": means natural gas produced from the processing of Raw Gas at
         the Terminal;

         "ECONOMIC DATE":  means 00:01 hours (London time) on 1 January 2003;

         "EMPLOYEES": means those persons employed wholly or mainly by BPEOC or
         its Affiliates in the Interests immediately prior to Completion whose
         presence as an employee is necessary for the efficient operation of the
         Interests;

         "ENCUMBRANCES": means all liens, charges, security interests royalties,
         pledges, options, net profit interests, royalty interests, deferred
         payments, carried interests, production payments, rights of
         pre-emption, mortgages and other third party rights, including claims
         relating to any of the foregoing;

         "ENVIRONMENT": means all or any of the following, alone or in
         combination, the air (including the air within buildings and the air
         within any other natural or man-made structures above or below ground
         or above or below water), water (including seawater inside or outside
         any territorial limits, freshwater and water under or within land or in
         pipes or sewerage systems), soil and land (including the seabed and
         land under water) and any ecological systems and living organisms
         supported by those media including man;

         "ENVIRONMENTAL LAW": means all European Community, international
         treaties, national, federal, provincial, state or local statutes, the
         common law, and any codes of law (having legal effect), in the form as
         existent and applied at the Economic Date in any relevant jurisdiction
         concerning:

         (a)     harm or damage to or protection of the Environment and/or the
                 provision of remedies in respect of or compensation for harm or
                 damage to the Environment; and/or

         (b)     emissions, discharges, releases or escapes into or the presence
                 in the Environment of Hazardous Substances or the production,
                 processing, management, treatment, storage, transport, handling
                 or disposal of Hazardous Substances or the disposal or
                 abandonment of any oil platform; and/or

         (c)     worker or public health and safety,

         and any bylaws, regulations or subordinate legislation, judgements,
         decisions, notices, orders, circulars, technical instructions, licences
         or permits and codes of practice from time to time issued or made
         thereunder at the Economic Date;

         "ENVIRONMENTAL LIABILITIES": means any claims, costs, charges,
         expenses, liabilities or obligations in respect of the Interests under
         any Environmental Law or in relation to cleaning up, decontamination
         of, removing and disposing of debris or any property (including, but
         not limited to, platforms, pipelines, plant, machinery, wells,
         facilities and all other offshore and onshore installations and
         structures) from and for reinstating any area of land, foreshore or
         seabed, wherever situated, whether such claims, costs, charges,
         expenses, liabilities or obligations are incurred under or pursuant to
         any of the Licensed Interest


                                      -3-

         Documents or under any Environmental Law or other obligation and
         including, without limitation, any residual liability for anticipated
         and/or necessary continuing insurance, maintenance and monitoring
         costs;

         "FIELD": means an oil or gas field which forms part of the Interests as
         described in Schedule 1;

         "FIELD FACILITIES": means the petroleum production, processing and
         transportation facilities and the interconnecting pipelines used in
         relation to a Field and wholly owned by the Field Group;

         "FIELD GROUP": means the parties to a JOA;

         "FINAL COMPLETION STATEMENT":  has the meaning given in clause 3.11;

         "FORTIES FIELD FACILITIES": means the Unit Facilities as defined in the
         Forties UOA at the date of this Agreement;

         "FORTIES UOA": means the Forties Field Unit Operating Agreement dated
         15 October 1985;

         "FPS": means certain facilities on the Forties C platform, the subsea
         pipeline from Forties C Platform to Cruden Bay via Unity, the BP Unity
         riser platform, the buried landline from Cruden Bay to the Terminal, an
         oil stabilisation plant at the Terminal, the onshore pipeline from the
         Terminal to the crude oil tankage at Dalmeny, the crude oil tankage at
         Dalmeny, the pipeline connecting Dalmeny to the Hound Point terminal
         and equipment at the Kerse of Kinneil and Grangemouth;

         "FPS PLATFORM SERVICES AGREEMENT": means the agreement of even date
         herewith between BPEOC (in its capacity as owner and operator of the
         FPS) and the Purchaser in respect of the continued operation of certain
         equipment relating to the FPS which is located on the Forties Field
         Facilities;

         "GLOBAL INSURANCE PROGRAM": means Purchaser's current insurance program
         and any renewal thereof which covers its assets and the liabilities for
         its operations throughout the world;

         "HAZARDOUS SUBSTANCES": means any wastes, pollutants, contaminants and
         any other natural or artificial substances (whether in the form of a
         solid, liquid, gas or vapour, and whether alone or in combination)
         which are capable of causing harm or damage to the Environment;

         "HISTORICAL DATA": means the information set out in the CD marked
         `Historical Data';

         "INTERESTS": means:

         (a)   BPEOC's undivided legal interest in the Licences;

         (b)   BPEOC's entire interest in and under:-


                                      -4-

                  (i)  each JOA;

                  (ii) the Licensed Interest Documents,

                  together in each case with all rights and obligations
                  attaching thereto and including but not limited to (i) the
                  right to take and receive a consequent share of all Petroleum
                  produced under the Licences on and after the Economic Date and
                  (subject to clauses 3.7 and 12) to receive the gross proceeds
                  from the sale or other disposition thereof; and (ii) a
                  consequent share of BPEOC's right, title and interest in and
                  to jointly-owned funds, jointly owned property and all other
                  assets which are or may be owned pursuant to or under any of
                  the Licensed Interest Documents but excluding the Retained
                  Assets;

         all as more particularly described in Schedule 1; and

         (c)   Data;

         "INTERIM COMPLETION STATEMENT":  has the meaning given in clause 3.9;

         "INTERIM PERIOD": means the period from and including the Economic Date
         up to and including the Completion Date;

         "INTERIM PERIOD ADJUSTMENT":  has the meaning given in clause 3.8;

         "JOAS": means those agreements, details of which are set out in
         Schedule 1 Parts 1(d) and 2(d) and, where the context so admits, any
         one or more of such agreements;

         "LIBOR": means the rate of interest per annum at which deposits of not
         less than $1,000,000 in Dollars are offered in the London Interbank
         offered interest rate market created by major London clearing banks for
         deposits in Dollars for a thirty day period as appearing on Telerate
         Page 3750 as of 11:00 a.m. (London time) on the first Business Day of
         the calendar month in which interest begins to accrue and thereafter on
         the first Business Day of each succeeding calendar month;

         "LICENCES": means the licences details of which are set out in Schedule
         1 Parts 1(b) and 2(b) and, where the context so admits, any one or more
         of such licences;

         "LICENCE OPERATOR": means the entity appointed operator pursuant to a
         JOA;

         "LICENCE ROYALTY": means royalty payable pursuant to the terms of the
         Licence, being the royalty abolished with effect from the Economic
         Date;

         "LICENSED INTEREST DOCUMENTS": means those documents referred to in
         Schedule 1 Parts 1(e) and 2(e) and, where the context so admits, any
         one or more of such documents;

         "LOSSES AND EXPENSES": means actions, proceedings, losses, damages,
         liabilities, claims, demands, costs and expenses including fines,
         penalties, clean-up


                                      -5-

         costs, legal and other professional fees and any VAT payable in
         relation to any such matter, circumstances or item;

         "NGLS": means hydrocarbons comprising primarily propane and butane
         which are produced from the processing of Raw Gas at the Terminal;

         "NOTIONAL CT": means an amount calculated in accordance with the
         principles of corporation tax as defined in Income and Corporation
         Taxes Act 1988 ("ICTA88"), including a basic rate of thirty per cent
         (30%) and an additional ten per cent (10%) supplementary charge in
         accordance with sections 91 to 93 of the Finance Act 2002 (sections
         501A to 501B ICTA88) arising in respect of profits from ring fence
         trades in accordance with Section 502 ICTA88;

         "NPR ADJUSTMENT": (being the Adjustment in respect of non-Petroleum
         receipts) has the meaning given in clause 3.6;

         "OBLIGATIONS":  has the meaning given in clause 6.2;

         "OIL": means crude oil which has been stabilised such that it is
         suitable for loading into tankships for sale;

         "OPERATOR": means where the context so admits any of or all of the
         following:

         (a)   a Licence Operator;

         (b)   a Pipeline Operator; and/or

         (c)   the Terminal Operator;

         "OTO":  the Oil Taxation Office of the Inland Revenue;

         "PARTY" or "PARTIES":  a party or parties to this Agreement;

         "PENSION SCHEME": means the BP Group pension scheme applicable to the
         Employees;

         "PETROLEUM":  shall have the meaning given in the Licences;

         "PETROLEUM SALES ADJUSTMENT":  has the meaning given in clause 3.7;

         "PIPELINE OPERATOR": the entity appointed operator in relation to a
         Pipeline System;

         "PIPELINE SYSTEM": a pipeline system through which Petroleum produced
         from a Field is transported;

         "POST COMPLETION DOCUMENTS": means those documents referred to in
         Schedule 1 Parts 1(h) and 2(h);

         "POUNDS", "L" or "STERLING":  pounds sterling of the United Kingdom;

         "PRT": Petroleum Revenue Tax as charged under the Oil Taxation Act
         1975;


                                      -6-

         "PURCHASER'S ACCOUNT": Bank One Chicago, Illinois, ABA No. 071000013,
         Account No. 5577446, Account Name: Apache Corporation Master;

         "PURCHASER'S GUARANTEE": means the deed entered into on or about the
         date of this agreement pursuant to which, inter alia, Apache
         Corporation guarantees in favour of the Seller, the obligations of the
         Purchaser hereunder;

         "PURCHASER'S SOLICITORS": means Herbert Smith, Exchange House, Primrose
         Street, London EC2A 2HS;

         "RAW GAS": means gas and interstage liquid hydrocarbons produced from
         the processing of pipeline liquids at the Terminal;

         "RAW GAS SALE AND PURCHASE AGREEMENT": means the agreement of even date
         herewith between Purchaser and BPEOC for the sale by Purchaser to BPEOC
         of Raw Gas produced from the Interests;

         "RELEVANT CLAIM": means any claim against Seller for breach of the
         Warranties;

         "RELEVANT THIRD PARTIES": means the parties, other than the Parties, to
         any or all of the Licensed Interest Documents;

         "RETAINED ASSETS": means the Brae, Buchan and MonArb risers and
         associated pig receivers, one 36" pig launcher, two drag reducing agent
         skids, eight drag reducing agent tanks, 1 corrosion inhibitor skid, 1
         corrosion inhibitor tank, the Forties Charlie export riser, and all
         valves, including subsea valves, pipework and control panels associated
         with the foregoing;

         "SECRETARY":  means the Secretary of State for Trade and Industry;

         "SECRETARY'S CONSENT": means the consent in writing of the Secretary to
         the transfer of the Interests to the Purchaser including the Licences;

         "SELLER": means BPEOC;

         "SELLER'S ACCOUNT": Citibank New York, Swift CITIUS33XXX; Account of BP
         International Limited, Account Number 40550445;

         "SELLER GROUP": means Seller, Seller's Affiliates and each of their
         officers, directors, agents, consultants and employees;

         "SOLE-CONTRACTORS": means those individuals, rather than corporate
         entities (save to the extent that such corporate entities are personal
         service companies), who have entered into contracts for services with
         BPEOC or its Affiliates as independent contractors for the supply of
         services in relation to the Interests or who have contracted with
         agencies who then supply the services of such individuals to BPEOC in
         relation to the Interests;

         "TERMINAL":  means the terminal at the Kerse of Kinneil;

         "TERMINAL OPERATOR": means the entity appointed operator of the
         Terminal;


                                      -7-

         "THE LONDON STOCK EXCHANGE":  means London Stock Exchange plc;

         "TRADED DATA": means, with respect to a Block comprised within the
         Interests, data which relates to an area outside such Block and which
         has been acquired by trade, purchase or otherwise by and on behalf of
         Seller (either alone or in conjunction with third parties) from a third
         party or parties, and/or data which relates to such a Block and has
         been acquired as aforesaid which in both cases cannot be provided to
         Purchaser because such transfer is prohibited by the agreement under
         which it was acquired;

         "UK LISTING AUTHORITY": means the Financial Services Authority acting
         in its capacity as the competent authority for the purposes of Part VI
         of the Financial Services and Markets Act 2000;

         "VAT": Value Added Tax as charged under the Value Added Tax Act 1994
         (as amended);

         "WARRANTIES": means the warranties given by Seller to Purchaser under
         clause 7.1 (including Parts 2 of Schedules 5 and 6); and

         "WORKING CAPITAL ADJUSTMENT": means the adjustment to the Consideration
         in respect of each Interest to be made pursuant to clause 3.4.

1.2      All references to clauses, recitals and Schedules are, unless otherwise
         expressly stated, references to clauses, recitals and schedules to this
         Agreement.

1.3      The headings in this Agreement are inserted for convenience only and
         shall be ignored in construing this Agreement. Unless the context
         otherwise requires in this Agreement the singular shall include the
         plural and vice versa.

1.4      Reference to statutory provisions shall be construed as reference to
         those provisions as amended, consolidated, extended or re-enacted from
         time to time.

1.5      Any document expressed to be "in the agreed form" means a document in a
         form approved by (and for the purpose of identification signed on
         behalf of) the Parties.

1.6      References in this Agreement to the words "include", "including" and
         "other" shall be construed without limitation.

1.7      References in this Agreement to any agreement shall be construed as a
         reference to any such agreement as the same may have been supplemented,
         amended and/or novated from time to time.

1.8      Where a warranty is qualified by the words "so far as Seller is aware",
         or any similar expression, such Warranty is given only to the extent
         that any of Mark Bly (Mid North Sea Business Unit Leader), David
         Campbell (Performance Unit Leader for Forties - Montrose - Arbroath),
         John Skipper (Assistant General Counsel), Bryan Tadeo (HSE Team Leader,
         Forties) and Graeme Young (Commercial Manager, Mid North Sea) are aware
         of the matters to which it refers


                                      -8-

         as at the date hereof and neither those persons nor Seller shall be
         required to make enquiries of any other person.


2.       SALE AND PURCHASE OF THE INTERESTS

         2.1.1    Subject to the terms of this Agreement, Seller hereby agrees
                  to sell with full title guarantee and free from all
                  Encumbrances (subject to the provisions of the Licensed
                  Interest Documents) to Purchaser and Purchaser hereby agrees
                  to acquire from Seller the Interests.

         2.1.2    The transfer referred to in clause 2.1.1 shall, as between the
                  Parties, be deemed for all purposes to be made with effect on
                  and from the Economic Date.

2.2      The obligations of the Parties to complete the sale and purchase of the
         Interests under this Agreement are conditional on fulfilment or waiver
         of the Conditions Precedent. If the Conditions Precedent have not been
         satisfied or waived on or before 30 September 2003 (the "Backstop
         Date") (or such later date as the Parties may agree) then, subject to
         clause 9, this Agreement shall automatically terminate. Following any
         such termination of this Agreement neither Party shall have any rights
         against the other Party in respect thereof, save for any pre-existing
         rights of any Party in respect of any prior breach hereunder or
         pursuant to Clause 9.

2.3      The Conditions Precedent consisting of necessary consents, approvals or
         waivers by Relevant Third Parties and governmental authorities shall be
         deemed satisfied upon receipt of such consents, approvals or waivers in
         form and substance reasonably satisfactory to Seller and Purchaser.

2.4      The Parties shall each use all reasonable endeavours to obtain
         fulfilment of the Conditions Precedent as soon as practicable and in
         any event by the Backstop Date. The Parties shall keep each other
         informed of the progress in satisfying these conditions and the date
         when they have been fulfilled.

2.5      Waiver of any of the Conditions Precedent shall require the mutual
         consent of Seller and Purchaser.


3.       CONSIDERATION

3.1      The consideration for the transfer of the Interests shall be the
         payment by Purchaser to Seller of the sum of $630,000,000 (six hundred
         and thirty million Dollars) (the "Consideration"), as adjusted pursuant
         to this Agreement.

3.2      Subject to clause 12, the Consideration shall be allocated as set out
         in Schedule 2. Seller and Purchaser agree that the said allocation is a
         just and reasonable apportionment of the Consideration.

3.3      Where any sums are taken into account in an Adjustment or are payable
         by Purchaser to Seller or by Seller to Purchaser pursuant to this
         clause 3, clause 6.4 or clause 12 (together the "Adjustment Clauses")
         or pursuant to a Relevant Claim


                                      -9-

         under clause 7, the same shall operate by way of increases or
         decreases, as the case may be, in the Consideration. The following
         principles shall apply in respect of the Adjustments and the
         Consideration:

         3.3.1    No item taken into account in calculating any one Adjustment
                  or other increases or decreases as the case may be under the
                  Adjustment Clauses or clause 7 shall be taken into account in
                  calculating any of the other Adjustments so as to result in a
                  Party making or receiving payment twice in respect thereof nor
                  will any Party be entitled under clause 6 to reimbursement of
                  any payment received from a third party to the extent such
                  payment has been taken into account (to the benefit of that
                  Party) in calculating any of the Adjustments.

         3.3.2    No adjustment to the Consideration shall be made in respect of
                  any matter to which clauses 6.6 or 6.7 apply.

3.4      WORKING CAPITAL ADJUSTMENT

         The Working Capital Adjustment, which if positive shall increase the
         Consideration and if negative shall reduce the Consideration, shall be
         the sum of all the amounts calculated separately in respect of the
         Interests as at the Economic Date by reference to the statements
         provided by the relevant Operators and otherwise in accordance with
         Schedule 3.

3.5      CASH CALLS ADJUSTMENT

         The Cash Calls Adjustment, which if positive shall increase the
         Consideration and if negative shall reduce the Consideration, shall be
         the net sum of the total amounts specified in clauses 3.5.1 and 3.5.2:

         3.5.1    the positive adjustments are the total amount of all cash
                  calls, billing invoices, claims, demands or statements paid
                  pursuant to the Licensed Interest Documents by the Seller or
                  on behalf of the Seller by the Operator, and which accrue or
                  relate to the period from the Economic Date until Completion;
                  and

         3.5.2    the negative adjustments are the total amount of all credits,
                  receipts, income, reimbursements or recoveries of any kind
                  (other than any credit, receipt, income, reimbursement or
                  recovery, which forms part of the Petroleum Sales Adjustment
                  under clause 3.7) received pursuant to the Licensed Interest
                  Documents by the Seller or on behalf of the Seller by the
                  Operator which accrue or relate to the period from the
                  Economic Date until Completion.

3.6      NPR ADJUSTMENT

         The NPR Adjustment, which shall decrease the Consideration, shall be
         the sum of all income and other receipts received by the Seller (other
         than those dealt with by the Petroleum Sales Adjustment under clause
         3.7 or otherwise dealt with in clause 3.5) in respect of the Interests
         during the Interim Period, provided that any such income or receipt
         which relates to any period prior to the Economic Date and


                                      -10-

         which has not been taken into account in the Working Capital Adjustment
         shall be for the benefit of the Seller and shall not result in any
         adjustment to the Consideration.

3.7      PETROLEUM SALES ADJUSTMENT

         3.7.1    The Petroleum Sales Adjustment, which shall decrease the
                  Consideration, shall be the sum of all receipts for the sale
                  and/or supply of Petroleum from and in relation to the
                  Interests that, on and from the Economic Date and in respect
                  of any Petroleum which (being Oil) is lifted or (being Raw
                  Gas) is delivered at any time on and after the Economic Date,
                  are received by or credited to the Seller.

         3.7.2    For the avoidance of doubt, the Parties agree that no
                  adjustment shall be made at Completion as part of the
                  Petroleum Sales Adjustment in respect of any receipts for the
                  sale and/or supply of Petroleum as aforesaid where such
                  receipts have not been received by or credited to the Seller
                  prior to the Completion Date. Instead, the Parties agree that
                  forthwith following each receipt by or crediting to the Seller
                  of any such receipts after Completion, the Seller shall pay
                  Purchaser the amount in Dollars or Sterling (as appropriate)
                  equal to such receipts. The Parties further agree that any
                  payments made by the Seller to Purchaser under this clause
                  3.7.2 shall be treated as a reduction in the Consideration
                  where any Petroleum (being Oil) is lifted or (being Raw Gas)
                  is delivered prior to the Completion Date and shall not be so
                  treated where such lifting or delivery takes place after the
                  Completion Date.

         3.7.3    Receipts attributed to Raw Gas in accordance with clause 3.7.1
                  shall be determined by reference to the price set out in the
                  Raw Gas Sale and Purchase Agreement. Receipts attributed to
                  Oil in accordance with clause 3.7.1 shall be determined by
                  reference to the arithmetic average of the Platts Crude Oil
                  Marketline quotations for each publication day for Forties
                  Blend f.o.b. Hound Point in Dollars per barrel for the month
                  of lifting in question.

3.8      INTERIM PERIOD ADJUSTMENT

         The Interim Period Adjustment, which shall increase the Consideration,
         shall be the sum of all expenditure incurred and paid in respect of the
         Interests by Seller including, without limitation, Licence Royalty,
         demurrage, brokers' fees (other than fees of stockbrokers and advisers
         engaged in relation to the matters referred to herein), employees
         salaries, rent, insurance premia and deductibles and all other costs
         and expenses incurred and paid by Seller in respect of the Interests
         during the Interim Period and which have not been met by cash calls or
         other payments taken into account under the foregoing provisions of
         this clause 3. Any such costs and expenses which relate to any period
         prior to the Economic Date and which have not been taken into account
         in the Working Capital Adjustment shall be for the cost of Seller and
         shall not result in any adjustment to the Consideration.


                                      -11-

         INTERIM COMPLETION STATEMENT/ESTIMATE OF ADJUSTMENTS

3.9      Seller shall provide Purchaser with a written statement (being a
         consolidation of separate statements prepared in respect of each
         Interest, with the separate statements attached), of the Consideration
         in Dollars, giving an estimate of the sum of all Adjustments
         (including, for the avoidance of doubt, the Working Capital Adjustment
         referred to under clause 3.4 and the Cash Calls Adjustment under clause
         3.5) which are expected to be required as at the Completion Date,
         together with amounts equivalent to interest in accordance with clause
         3.15 to be made hereunder in respect of the Interests. Such statement
         shall be provided no later than seven (7) Business Days prior to
         Completion. Seller may update the same and the Parties shall endeavour
         to agree the statement before Completion, failing which the matter
         shall be dealt with in accordance with clauses 3.11 and 3.12. This
         interim completion statement (the "Interim Completion Statement") shall
         be in the format set out in Schedule 4.

3.10     If any of the amounts or portions thereof contained in the Interim
         Completion Statement to be delivered pursuant to clause 3.9 have not
         been agreed or determined prior to Completion, the disputed amounts or
         portions of the Adjustments shall be left out of account and shall be
         dealt with as part of the Final Completion Statement in accordance with
         clauses 3.11 and 3.12, and the undisputed balances of the Adjustments
         shall be set off against each other. The resultant balance in relation
         to the Interests shall be added to or subtracted from (as the case may
         be) the amount of the Consideration stated in clause 3.1, and such
         amount so adjusted shall be payable at Completion.

3.11     FINAL COMPLETION STATEMENT/FINAL ADJUSTMENTS

         Within sixty days after Completion, and without prejudice to the
         provisions of clause 6, Seller shall provide Purchaser with a written
         statement (being a consolidation of separate statements prepared in
         respect of the Interests, with the separate statements attached),
         together with reasonably detailed supporting documentation, giving the
         final amount of the Consideration and all Adjustments to be made
         hereunder in respect of the Interests (including any amounts left out
         of account under clause 3.10) together with amounts equivalent to
         interest in accordance with clause 3.15. If the Parties shall fail to
         agree any such amounts in dispute (the "Disputed Amounts") within
         fifteen Business Days of receipt by Purchaser, the statement shall be
         referred for determination in accordance with the provisions of clause
         3.12. Any amounts so agreed within fifteen Business Days (the "Second
         Adjustment"), to the extent not already paid or taken into account on
         Completion, shall be paid by Purchaser or Seller within five Business
         Days following agreement of the relevant Parties. Payment of the
         Disputed Amounts or portions thereof shall be made within five Business
         Days following either agreement of the Parties or determination under
         clause 3.12 (as the case may be). This final completion statement (the
         "Final Completion Statement") shall be in the format set out in
         Schedule 4. For the avoidance of doubt, the provisions of this clause
         3.11 shall not apply to any tax adjustments pursuant to clause 12.


                                      -12-

3.12     INDEPENDENT DETERMINATION

         If the Parties cannot reach agreement on the contents of all or part of
         the statements referred to in clauses 3.9 and/or 3.11 within the time
         limit provided in clause 3.11, the Disputed Amounts may be referred by
         any Party for determination by an independent chartered accountant
         nominated by the Parties or, in the absence of agreement between the
         Parties within five Business Days of a Party notifying the other that
         it proposes to refer the dispute to an expert, by the President of the
         Institute of Chartered Accountants in England and Wales. Within ten
         Business Days after the appointment of such expert, each Party may
         submit to the expert a statement of the nature of the dispute, a
         description of the submitting Party's claims with respect thereto, and
         any other supporting documentation or materials with respect thereto
         that the submitting Party desires the expert to consider. The Party
         submitting such statement shall provide a copy thereof to the other
         Party, who shall have five Business Days from receipt thereof to submit
         an answering statement to the expert. The nominated chartered
         accountant shall be afforded such access to books, records, accounts
         and documents in the possession of the Parties as he may reasonably
         request, and he shall act as expert not as arbitrator. The said
         accountant's determination shall, in the absence of fraud or manifest
         error or bias, be final and binding on the Parties, his fees and
         disbursements shall be borne by Seller as to one half and Purchaser as
         to the other half and each Party shall bear its own costs in respect of
         such reference.

3.13     Seller shall provide Purchaser with copies of all Operator's reports,
         billing statements and correspondence and any and all other relevant
         documentation in its possession or under its control necessary to
         support the statements referred to in clauses 3.9 and 3.11. The Parties
         shall liaise on the compilation and agreement of the said statements.

3.14     FINANCIAL INFORMATION

         Both prior to and after Completion, Seller shall provide Purchaser with
         access to Seller's financial records for the Interests for the calendar
         years 2001 and 2002 which were previously made available to Seller's
         auditors for purposes of preparing Seller's annual audited and
         quarterly reviewed financial statements for those years and to Seller's
         corresponding financial records for any portion of 2003 prior to
         Completion, including in each case records with respect to direct
         operating costs with respect to each of the Interests and the net
         revenues from such Interests and such other information as may be
         required for Purchaser's Form 8-K filing with respect to the
         transactions contemplated by this Agreement. Seller shall cause
         Seller's and Seller's Affiliates' personnel to cooperate with Purchaser
         in providing such access and to reasonably assist Purchaser in locating
         and interpreting such records and Seller shall cause Seller's
         contractor Accenture to provide reasonable assistance to Purchaser in
         the preparation of certain supporting financial schedules and audit
         work papers. The cost incurred by Seller in providing the financial
         data to Purchaser and assisting Purchaser shall be borne by Purchaser.
         Purchaser releases Seller Group from and shall fully protect, defend,
         indemnify and hold Seller Group harmless from and against any and all
         claims relating to, arising out of, or connected with, directly or
         indirectly, Seller's


                                      -13-

         preparation or furnishing of any such records to Purchaser, any
         actions, representations or certifications of Seller's and its
         Affiliates' personnel or auditors with respect to the information
         contained in such records, or Purchaser's use of the information
         contained in such financial records, regardless of cause or of any
         negligent acts or omissions (including sole negligence, concurrent
         negligence or strict liability), breach of duty (statutory or
         otherwise), violation of law, or other fault of Seller Group, or any
         pre-existing defect.

3.15     TIME-VALUE ADJUSTMENTS

         3.15.1   An amount equivalent to simple interest (calculated on a daily
                  basis on the basis of a 365 day year) at the Agreed Rate shall
                  be payable to Seller on the amount of the Consideration stated
                  in clause 3.1 from the Economic Date up to and including the
                  Completion Date.

         3.15.2  In respect of the Adjustments:

                  (a)     an amount equivalent to simple interest (calculated on
                          a daily basis on the basis of a 365 day year) at the
                          Agreed Rate shall be payable on the Working Capital
                          Adjustment from the Economic Date up to and including
                          the Completion Date, and, in the case of that element
                          of the Second Adjustment attributable to it or
                          Disputed Amounts, thereafter up to and including the
                          date of settlement thereof;

                  (b)     an amount equivalent to simple interest (calculated on
                          a daily basis on the basis of a 365 day year) at the
                          Agreed Rate shall be payable on each cash call or
                          invoice, claim, demand or statement (adjusted in
                          accordance with clause 12) comprised in the Cash Calls
                          Adjustment from the date on which such cash call or
                          invoice, claim, demand or statement is paid by Seller
                          up to and including the date of settlement of such
                          element of the Cash Calls Adjustment;

                  (c)     an amount equivalent to simple interest (calculated on
                          a daily basis on the basis of a 365 day year) at the
                          Agreed Rate shall be payable on each receipt comprised
                          in the NPR Adjustment from the date such income is
                          received by the Seller up to and including the date of
                          settlement of such element of the NPR Adjustment;

                  (d)     an amount equivalent to simple interest (calculated on
                          a daily basis on the basis of a 365 day year) at the
                          Agreed Rate shall be payable on each receipt comprised
                          in the Petroleum Sales Adjustment from the date of
                          such receipt by or credit to the Seller up to and
                          including the date of settlement of such element of
                          the Petroleum Sales Adjustment; and

                  (e)     an amount equivalent to simple interest (calculated on
                          a daily basis on the basis of a 365 day year) at the
                          Agreed Rate shall be payable on each item of
                          expenditure comprised in the Interim


                                      -14-

                          Period Adjustment from the date such item of
                          expenditure is paid by the Seller up to and including
                          the date of settlement of such element of the Interim
                          Period Adjustment.

3.16     Where any sums payable by Purchaser to Seller or by Seller to Purchaser
         pursuant to clauses 3, 6 or 7 are expressed in currencies other than
         Dollars, the same shall be translated into Dollars at the arithmetical
         average of the spot closing midpoint rates quoted in the Financial
         Times for the currency concerned on each Business Day during the
         calendar month prior to the month in which the relevant payment is made
         or received (as the case may be) and shall be paid in Dollars.

3.17     Where this Agreement provides for any payment to the Seller's Account,
         the Seller irrevocably authorises and instructs the Purchaser to make
         that payment to the Seller's Account, delivery to which account shall
         be an effective discharge of the Purchaser's obligation to pay the
         amount concerned. The Purchaser shall not be concerned to see to the
         application of any such amounts so paid. Likewise, where this Agreement
         provides for any payment to the Purchaser's Account, the Purchaser
         irrevocably authorises and instructs the Seller to make that payment to
         the Purchaser's Account, delivery to which account shall be an
         effective discharge of the Seller's obligation to pay the amount
         concerned. The Seller shall not be concerned to see to the application
         of any such amounts so paid.


4.       INTERIM PERIOD

4.1      During the Interim Period (to the extent the same falls after the date
         hereof), Seller shall:

         4.1.1    to the extent practicable in the circumstances consult with
                  Purchaser in relation to any material decision in connection
                  with the Interests (in particular in respect of the
                  non-compliant X-10 oil cooler on the Forties Charlie platform)
                  and take reasonable account of Purchaser's reasonable
                  representations but so that nothing in this sub-clause shall
                  operate to fetter the discretion of the Seller in exercising
                  its votes in respect thereto;

         4.1.2    not approve any work programme, budget, expenditure or capital
                  commitment relating to any Licence involving expenditure in
                  excess of L1,000,000 (net Seller's share) in any case other
                  than:

                  (a)     any such expenditure covered by any budget approved
                          prior to the date of this Agreement; or

                  (b)     any such expenditure in respect of which Purchaser has
                          given its prior written approval (not to be
                          unreasonably withheld or delayed); or

                  (c)     any expenditure necessitated by any emergency (in
                          which case Seller shall consult with Purchaser to the
                          extent practicable in the circumstances);


                                      -15-

         4.1.3    continue to carry on their activities in relation to the
                  Interests in the ordinary and usual course (and in accordance
                  with the terms of the Licences and other Licensed Interest
                  Documents) so as to protect and maintain the same in
                  accordance with good oilfield practice;

         4.1.4    consult with the Purchaser with regard to the Interests and
                  co-operate with the Purchaser so as to ensure an efficient
                  handover of the Interests on Completion;

         4.1.5    generally keep the Purchaser in a timely manner informed of
                  matters (not of a routine or minor nature) relating to the
                  Interests;

         4.1.6    not, without the Purchaser's written consent (not to be
                  unreasonably withheld or delayed), waive, compromise or settle
                  any material right or claim with respect to the Interests
                  insofar as such right or claim relates or is capable of
                  relating to periods after the Economic Date;

         4.1.7    not, without the Purchaser's written consent (not to be
                  unreasonably withheld or delayed), encumber, sell, lease or
                  otherwise dispose of any of the Interests (excluding sales of
                  production therefrom in the ordinary course of business
                  consistent with past practices), or purport to do any of the
                  same;

         4.1.8    not, without the Purchaser's written consent (not to be
                  unreasonably withheld or delayed), terminate, amend, or
                  modify, or agree to terminate, amend or modify, any of the
                  Licensed Interest Documents or withdraw from the Licences (or
                  any of them);

         4.1.9    not, without the Purchaser's written consent (not to be
                  unreasonably withheld or delayed), and excluding any contract
                  or agreement covered by any budget approved prior to the date
                  hereof, enter into a contract or agreement relating to the
                  Interests and attributable to the period after the Economic
                  Date that is (i) a contract or agreement with an Affiliate of
                  Seller; or (ii) a contract or agreement for which Purchaser
                  shall have financial responsibility after Completion in an
                  amount in excess of L1,000,000; or (iii) a contract or
                  agreement which materially interferes with the operation of
                  the Interests in the manner in which they were operated as of
                  the Economic Date; or (iv) a joint operating agreement,
                  unitization agreement or co-operation agreement;

         4.1.10   provide the Purchaser with all reasonable information and
                  assistance requested by the Purchaser so as to enable the
                  Purchaser to include the Interests under its Global Insurance
                  Program.

4.2

         4.2.1    Notwithstanding any other provision of this Agreement, if
                  prior to Completion (but not thereafter), an event giving rise
                  to physical damage to the Forties Field Facilities occurs
                  which causes a total shutdown in production from the Interests
                  which total shutdown is estimated in good faith by both
                  Parties (as evidenced by written agreement to that effect) as


                                      -16-

                  likely to continue for not less than one year from the date of
                  such event, (or if for any reason the Parties are unable or
                  unwilling to agree upon such estimate within fifteen (15)
                  Business Days of a request to do so from either Party,
                  estimated as aforesaid by an independent expert appointed by
                  the Parties, or if the Parties are unable to agree on such
                  appointment within twenty-four (24) hours, as appointed by the
                  President of the Institute of Petroleum); then the Purchaser
                  shall have the right as prescribed in clause 4.2.2 to
                  terminate this Agreement by notice in writing to the Seller,
                  without either Party having any liability to the other. Save
                  in the event of fraud, the agreement of the Parties or the
                  expert's determination, as the case may be, shall be final and
                  binding on the Parties and the expert shall be deemed to be
                  acting as an expert and not as an arbitrator.

         4.2.2    If the Parties agree or the expert determines that a total
                  shutdown as provided in clause 4.2.1 is likely to continue for
                  not less than one (1) year from the date of such event, the
                  Purchaser shall be entitled at any time prior to the close of
                  business on the fifth (5th) Business Day after the Parties
                  reach agreement or receive the expert's determination to give
                  notice to the Seller to terminate this Agreement. If the
                  Purchaser does not give such a notice or is not entitled to
                  give such a notice by reason of the Parties reaching agreement
                  or the expert determining that a total shutdown is not likely
                  to continue for one year or longer, then the Parties shall
                  (subject to the fulfilment or waiver of the Conditions
                  Precedent) proceed to Completion or if the date of Completion
                  has been delayed pursuant to clause 4.2.3 then as soon as
                  reasonably practicable and in any event within ten (10)
                  Business Days of such agreement or the receipt of such
                  determination.

         4.2.3    If the Parties' estimate or expert's determination referred to
                  in clause 4.2.1 has not been agreed or received, as the case
                  may be, by the Purchaser prior to the date which is five (5)
                  Business Days prior to Completion then the Completion shall be
                  delayed until after receipt by the Purchaser of the Parties'
                  estimate or expert's determination (subject to the fulfilment
                  or waiver of the Conditions Precedent).

         4.2.4    If the Purchaser does not exercise any right it may have under
                  this clause 4.2 to terminate this Agreement and proceeds to
                  Completion, the Purchaser shall be deemed to have waived any
                  and all other rights it may have hereunder or otherwise in
                  relation to the event referred to in clause 4.2.1 it being
                  accepted by the Parties that the right of termination shall be
                  in lieu of any other right of the Purchaser in relation to
                  such event, including any right to claim damages, make any
                  claim in respect of the Warranties or seek any reduction in
                  the Consideration.

         4.2.5    The rights set out in this clause 4.2 shall not apply in
                  respect of any event giving rise to physical damage to the
                  Forties Field Facilities which occurs after Completion.


                                      -17-

4.3     INTERIM PERIOD RISK AND INSURANCE

        4.3.1  Subject to clause 4.2 and the other provisions of this Agreement,
               the Purchaser shall accept the assets comprising the Interests in
               the physical condition in which they exist at the date of this
               Agreement and, notwithstanding that title will not pass until
               Completion, shall assume the risk of damage thereto or the
               destruction thereof as from the date of this Agreement.

        4.3.2  The Purchaser shall with effect from the date of this Agreement
               until this Agreement is terminated or Completion takes place (as
               the case may be) ensure that the insurance coverage provided by
               its Global Insurance Program includes the Interests. The
               Purchaser will not vary such insurance coverage in respect of the
               Interests without the Seller's prior written consent (not to be
               unreasonably withheld or delayed). The Purchaser shall provide to
               the Seller evidence that the Interests have been included under
               the Global Insurance Program as soon as reasonably practicable
               after the date of this Agreement.

        4.3.3  If after the date of this Agreement the Interests sustain damage
               or are destroyed, the Seller shall cooperate with and provide all
               reasonable assistance and provide all such relevant information
               to the Purchaser or its insurers (including such insurers'
               representatives and contractors) as may be reasonably requested
               by the Purchaser or its insurers, so as to enable the Purchaser
               to effect recovery under the Global Insurance Program.

4.4     Without prejudice to clause 4.1, Seller shall (subject to any
        confidentiality obligations by which it is bound, from which obligations
        Seller shall use reasonable endeavours to procure its release) ensure
        that pending Completion the Purchaser is kept informed in a timely
        manner of all material matters in relation to the Interests, including,
        but not limited to:

         (a)     the making of any cash call;

         (b)     the approval of any AFE;

         (c)     the adoption or proposal of, or amendment to, any work
                 programmes and budgets;

         (d)     the receipt of Operators' billing statements and invoices; and

         (e)     the receipt of any Data.

4.5      After execution of this Agreement, Seller shall make available (during
         Seller's regular business hours and at their current location) for
         review by Purchaser and its representatives all Data. If Purchaser
         requests copies of any of the Data, Seller shall use reasonable efforts
         to provide the requested copy to Purchaser at Purchaser's expense.


                                      -18-

4.6      As soon as practicable after execution of this Agreement, Seller and
         Purchaser will create a transition team ("TRANSITION TEAM") consisting
         of approximately three (3) persons on each side for the purpose of:

         (a)      providing information and background to Purchaser and
                  Purchaser's personnel relating to the operation of the
                  Interests (including the provision of services under the FPS
                  Platform Services Agreement);

         (b)      providing liaison with the Employees and any other personnel
                  of the Seller who are responsible for such operations; and

         (c)      planning the anticipated transfer of operatorship of the
                  Interests to Purchaser.

         Seller will allow the Purchaser's representatives on the Transition
         Team reasonable access to Seller's premises at Dyce, Aberdeen and to
         sites on-shore and off-shore associated with the operation of the
         Interests which sites are under Seller's control all at Purchaser's
         sole risk and expense.


5.       COMPLETION

5.1      Completion under this Agreement shall take place at the offices of
         Herbert Smith, Brussels (or at such other location as the Parties may
         agree) on the Business Day which falls ten Business Days after the date
         on which the last of the Conditions Precedent have been fulfilled or
         waived (or at such other time as the Parties may agree). Promptly after
         receipt of a governmental or Relevant Third Party consent, approval or
         waiver which is a Condition Precedent, the receiving Party shall notify
         the other Party that such consent, approval or waiver has been
         obtained.

5.2      On the Completion Date all but not part only of the following business
         shall be transacted:

         5.2.1   Purchaser shall:

                  (a)     pay to Seller the Consideration, as adjusted in
                          accordance with clauses 3.3 to 3.10 inclusive together
                          with amounts equivalent to interest pursuant to clause
                          3.15, by means of telegraphic transfer in immediately
                          available funds to Seller's Account on such Completion
                          Date;

                  (b)     deliver to Seller (to the extent not already delivered
                          prior to Completion) a copy of the relevant consents,
                          approvals, confirmations or waivers, necessary to
                          satisfy the Conditions Precedent and obtained by or on
                          behalf of Purchaser;

                  (c)     deliver to Seller (to the extent not already delivered
                          prior to Completion) a copy, certified as a true copy
                          and in full force and effect by a director or the
                          secretary of Purchaser, of a resolution of the board
                          of directors of Purchaser authorising its entry into
                          the transactions contemplated by this Agreement and


                                      -19-

                          authorising a person or persons to sign the same and
                          the Completion Documents on behalf of Purchaser; and

                  (d)     execute and deliver those of the Completion Documents
                          to which it is a signatory.

         5.2.2    Seller shall deliver to Purchaser (to the extent not already
                  delivered prior to Completion):

                  (a)     the Completion Documents duly executed by all the
                          parties thereto other than Purchaser (and, in the case
                          of the Deeds of Licence Assignment, the Secretary);

                  (b)     a copy of other relevant consents, approvals,
                          confirmations or waivers, necessary to satisfy the
                          Conditions Precedent and obtained by or on behalf of
                          Seller; and

                  (c)     a copy, certified as a true copy and in full force and
                          effect by a director or the secretary of Seller, of a
                          power of attorney authorising the execution of this
                          Agreement and the Completion Documents on behalf of
                          Seller.

5.3      Seller and Purchaser undertake to each other and agree to use all
         reasonable endeavours to ensure the execution of each of the Post
         Completion Documents (to the extent not delivered at Completion) by all
         parties thereto as soon as possible after Completion.

5.4      Without prejudice to its obligations under clause 4, Seller shall
         ensure that (to the extent not delivered prior to Completion) the
         Licensed Interest Documents and all Data in the possession or control
         of Seller (or copies thereof, if originals are not in Seller's
         possession) are made available for collection by Purchaser at its own
         expense within normal business hours as soon as reasonably practicable
         after the Completion Date.

5.5      Purchaser acknowledges that Seller shall have the right to retain
         copies of any of the Licensed Interest Documents, subject to the same
         being maintained in confidence, and the provisions of clause 9 shall
         apply to Seller in the same way as they apply to Purchaser.

5.6      Purchaser undertakes that, following Completion, it shall not and it
         shall procure that its Affiliates shall not make use of any stationery,
         invoices, forms, seals, trade marks, logos and any other similar
         articles or symbols showing the expression "BP", "Amoco" or "BP Amoco"
         or any other expression likely to suggest a connection with the BP
         group of companies, provided that any signs, placards or other marks
         bearing such trade marks, logos and symbols of Seller or the BP group
         of companies shall be removed by Purchaser from the properties
         comprising the Interests within 45 Business Days after the Completion
         Date.

5.7      Notwithstanding Completion:


                                      -20-

         5.7.1    each provision of this Agreement (and any other document
                  referred to in it) not performed at or before Completion but
                  which remains capable of performance;

         5.7.2   the Warranties; and

         5.7.3    all covenants and other undertakings contained in or entered
                  into pursuant to this Agreement,

         will remain in full force and effect and (except as otherwise expressly
         provided) without limit in time.


6.       INDEMNITIES

6.1      The provisions of this clause 6 shall only take effect once Completion
         has occurred. All adjustments and reimbursements made and the
         ascertainment of all Obligations and Benefits under this clause 6 will
         be calculated using the accruals method of accounting.

6.2      Seller shall be liable for costs, charges, expenses, liabilities and
         obligations in connection with or arising out of the Interests (other
         than Environmental Liabilities and the Decommissioning Liabilities)
         (together "Obligations") which accrue in or relate to any period before
         the Economic Date and Seller shall be entitled to all income, receipts,
         rebates and other benefits in connection with or arising out of the
         Interests (together "Benefits") which accrue in or relate to any period
         before the Economic Date.

6.3      Purchaser shall be liable for all Obligations and entitled to all
         Benefits which accrue in or relate to any period on or after the
         Economic Date.

6.4      Subject to clause 6.9, save to the extent that the Consideration is
         adjusted to take account thereof under clause 3, and subject to clauses
         7 and 12:

         6.4.1    if any Obligations are incurred by Seller in respect of any
                  period on or after the Economic Date, Purchaser shall
                  reimburse and indemnify Seller in respect thereof;

         6.4.2    if any Obligations are incurred by Purchaser in respect of any
                  period prior to the Economic Date, Seller shall reimburse and
                  indemnify Purchaser in respect thereof;

         6.4.3    if any Benefits accrue to Seller in respect of any period on
                  or after the Economic Date, Seller shall account to and
                  reimburse Purchaser in respect thereof; and

         6.4.4    if any Benefits accrue to Purchaser in respect of any period
                  prior to the Economic Date, Purchaser shall account to and
                  reimburse Seller in respect thereof.


                                      -21-

6.5      Any amount to be paid or reimbursed in accordance with clause 6.4 or
         any other provision of this clause 6 shall (i) in the case of those
         amounts that arise prior to the Completion Date, be paid or reimbursed
         on Completion and (ii) in the case of those amounts that arise after
         the Completion Date be paid or reimbursed within ten Business Days of
         receipt thereof (or, in the case of Obligations, within ten Business
         Days of receipt of notification from the Party which has incurred such
         Obligations) in each case, to the Seller's Account or the Purchaser's
         Account (as the case may be).

6.6      For the avoidance of doubt and without prejudice to the generality of
         the foregoing provisions of this clause 6, as between Seller and
         Purchaser, Purchaser shall at its cost and expense be responsible for
         decommissioning and/or removing and/or making safe all plant, equipment
         and machinery, wells and other installations (including pipelines) and
         facilities relating to operations under the Licences and/or under each
         and any JOA or other Licensed Interest Document to the extent that such
         obligations are attributable to the Interests whether such Losses and
         Expenses are incurred under or pursuant to any of the Licence Documents
         or under statutory, common law or other obligation. The Purchaser
         covenants that it shall indemnify and hold Seller and its Affiliates
         harmless against any and all Losses and Expenses which Seller or any of
         its Affiliates may incur arising out of or in connection with the
         Decommissioning Liabilities regardless of whensoever such
         Decommissioning Liabilities may arise or may have arisen, regardless of
         whosoever is or was a licensee under the relevant Licence or a party to
         the relevant JOA or owned or leased the relevant property and
         regardless of whether such Losses and Expenses arise as a consequence
         of negligence on the part of Seller or any of its Affiliates, Provided
         that, for the avoidance of doubt, Purchaser shall not be required to
         reimburse Seller for amounts actually expended by Seller prior to the
         Economic Date in respect of Decommissioning Liabilities.

6.7      Purchaser covenants that it shall indemnify and hold Seller and its
         Affiliates harmless against any Losses and Expenses Seller or any of
         its Affiliates may incur arising out of or in connection with the
         Environmental Liabilities regardless of whensoever such Environmental
         Liabilities may arise or may have arisen, regardless of whosoever is or
         was a licensee under the relevant Licence or a party to the relevant
         JOA or owned or leased the relevant property and regardless of whether
         such Losses and Expenses arise as a consequence of negligence or breach
         of any Environmental Law on the part of Seller or any of its
         Affiliates.

6.8      Notwithstanding clauses 6.2 and 6.7, Seller shall indemnify and hold
         harmless the Purchaser and its Affiliates against all fines and
         financial penalties which are imposed under any Environmental Law in
         respect of the following events:

         6.8.1    the rupture of a gas pipeline on the Forties Alpha platform
                  which resulted in the release of an estimated amount of 1
                  tonne of gas in November 2002; and

         6.8.2    the escape of an estimated amount of 30-40 tonnes of diesel
                  from the Forties Alpha platform in December 2002.


                                      -22-

6.9      For the avoidance of doubt, and without prejudice to the provisions of
         clauses 6.2, 6.3 and 6.4, (i) any Benefits or Obligations (including
         the cost of any audit) accruing in respect of the Interests in the form
         of amounts receivable or payable resulting from an audit pursuant to a
         JOA or from any other subsequent adjustment in relation to the
         operation of, and expenditure attributable to, the Interests in the
         period prior to the Economic Date shall accrue to Seller, and (ii) any
         such Benefits or Obligations attributable to the Interests in the
         period from and after the Economic Date shall accrue to Purchaser.
         Where any such audit takes place after the Completion Date, Purchaser
         shall use all reasonable endeavours to enable Seller to make
         representations directly to any relevant Operator and shall in any
         event be obliged to take account of Seller's representations in
         connection with such audit and to notify the relevant Seller of any
         audit adjustment as soon as practicable after the results of such audit
         are known. If, as a result of any audit adjustment or otherwise, either
         Seller or Purchaser is, on the principles set out in clauses 6.2, 6.3
         and 6.4, so liable to pay any amount to the other, then, to the extent
         that the Consideration has not already been adjusted pursuant to the
         provisions of clause 3 in respect thereof, or the amount has not
         otherwise been paid in accordance with clause 6.4, such amount shall be
         paid to Seller's Account or the Purchaser's Account (as appropriate)
         within thirty Business Days after the amount receivable or payable as a
         result of such an audit or other subsequent adjustment has been taken
         into account by the relevant Operator in the Operator's billing
         statement.

6.10     Notwithstanding any provision of this clause 6, the Seller shall not be
         entitled to claim or reclaim under any of the indemnities in this
         clause, any amount payable or paid to the Purchaser for breach of
         warranty or other breach of this Agreement.


7.       WARRANTIES

7.1      Subject to the provisions of this clause 7 and save as fairly disclosed
         under the terms of the Disclosure Letter, Seller hereby warrants to
         Purchaser in the terms set out in Part 2 of Schedule 5 and Part 2 of
         Schedule 6 and as follows:

         7.1.1    it is a licensee of the Licences and the sole legal and
                  beneficial owner of the Interests and following fulfilment of
                  the Conditions Precedent, Seller will at Completion have the
                  right to transfer and assign full legal and beneficial
                  ownership of the Interests to Purchaser;

         7.1.2    subject to the provisions of the Licensed Interest Documents,
                  no Encumbrance is in existence and in force over the Interests
                  nor, subject as aforesaid, is there in effect any agreement or
                  commitment to create the same;

         7.1.3   it has not:

                  (a)     committed any material breach of the Licences or any
                          of the Licensed Interest Documents; nor


                                      -23-

                  (b)     received notice that any of the parties to any of the
                          Licences or Licensed Interest Documents is in breach
                          thereof,

                  which breach in either case, at the date of making this
                  statement, is of a material nature and is subsisting;

         7.1.4

                  (a)     the Licences and all rights and interests of it
                          thereunder or deriving therefrom are in full force and
                          effect;

                  (b)     no act or omission of it has occurred which would
                          entitle the Secretary to revoke, rescind, avoid,
                          repudiate or terminate any of the Licences;

                  (c)     so far as it is aware, no act or omission of any
                          licensee of the Licences (other than Seller) has
                          occurred which would entitle the Secretary to revoke,
                          rescind, avoid, repudiate or terminate any of the
                          Licences; and

                  (d)     no notice has been given to it by the Secretary or, so
                          far as it is aware, to any other licensee of the
                          Licences, notifying or indicating an intention on the
                          part of the Secretary to revoke, rescind, avoid,
                          repudiate or terminate any of the Licences;

         7.1.5    no Licence is in the course of being surrendered in whole or
                  in part;

         7.1.6    all accrued obligations and liabilities imposed by the
                  Licences on it, including without limitation the work
                  obligations arising from the Licences, have been duly
                  fulfilled and discharged and there is no outstanding work
                  obligation to be fulfilled by it under the Licences or any of
                  them;

         7.1.7

                  (a)     it is not a party to any litigation or arbitration or
                          administrative proceedings relating to the Interests
                          or any portion thereof in respect of which a writ or
                          summons or other formal pleading has been served or
                          judgement issued;

                  (b)     there are no claims (whether or not formulated within
                          a formal pleading as aforesaid) or disputes in
                          relation to, and which are likely materially to
                          prejudice or detrimentally affect in any material
                          manner, the Interests;

                  (c)     it is not aware that any such litigation, arbitration,
                          administrative proceedings claim or dispute are
                          threatened or pending either by or against it;


                                      -24-

                  (d)     there are no facts known to it which are likely to
                          give rise to any claim or dispute which is likely so
                          to prejudice or detrimentally affect in any material
                          manner the Interests; and

                  (e)     so far as it is aware, none of the other licensees of
                          the Licences or the parties to the Licensed Interest
                          Documents is a party to any litigation, arbitration or
                          administrative proceedings or any claim or dispute or
                          judgment in relation to, and which is likely to
                          prejudice or detrimentally affect in any material
                          manner, the Interests;

         7.1.8   the Licensed Interest Documents:

                  (a)     are the only material documents of which it is aware
                          which govern or relate to the creation, existence and
                          validity of the Interests, other than those which are
                          otherwise disclosed in the Disclosure Letter; and

                  (b)     are the only material agreements to which it is party
                          relating to the Interests;

         7.1.9    it is duly incorporated with limited liability and validly
                  existing under the laws of England and Wales;

         7.1.10   the documents which contain or establish its constitution
                  incorporate provisions which authorise, and all necessary
                  corporate action has been taken by it to authorise it to
                  execute and deliver this Agreement and perform the
                  transactions contemplated by this Agreement;

         7.1.11   the signing and delivery of this Agreement and, subject to
                  fulfilment of the Conditions Precedent, the performance of any
                  of the transactions contemplated by this Agreement will not
                  contravene or constitute a default under any provision
                  contained in any agreement, instrument, law, judgment, order,
                  licence, permit or consent by which it or any of its
                  Affiliates or their respective assets is bound or affected;

         7.1.12   it has not given to or received from any other party to any of
                  the Licensed Interest Documents any notice of withdrawal in
                  whole or in part from any or all of the Licences or of any
                  proposed assignment of any interest arising thereunder, which
                  notice is in either case still current;

         7.1.13   so far as it is aware, no event or incident has occurred in
                  respect of the Interests (other than pursuant to prevailing
                  oil and gas field practice conducted in accordance with any
                  legislation in force at the time of the relevant activity)
                  which has given rise to any Environmental Liability;

         7.1.14

                  (a)     the Interests have been owned and operated in
                          compliance in all material respects with all
                          applicable laws including any European Community,
                          international treaties, national, federal,


                                      -25-

                          provincial, state or local statutes, the common law,
                          and any codes of law applicable to the Interests; and

                  (b)     Seller has received no written notice that Seller's
                          ownership and operation of the Interests violates in
                          any material respects any applicable laws;

         7.1.15

                  (a)     all of the plant and equipment included in the
                          Interests complies in all material respects with all
                          applicable legal requirements;

                  (b)     the average daily production from the Interests
                          between 24 December 2002 and 7 January 2003 (both
                          dates inclusive) was 46,500 barrels per day of oil
                          equivalent volumes and the average daily production
                          from the Interests in the fourth quarter of 2002 was
                          40,400 barrels per day of oil equivalent volumes;

         7.1.16   Seller has all governmental licences, permits, authorisations,
                  consents and permissions necessary to own and operate the
                  Interests as presently owned and operated; such licences,
                  permits, authorisations, consents and permissions are in full
                  force and effect and no material violations exist with respect
                  to any of the same;

         7.1.17   Seller has furnished to Purchaser true, correct and complete
                  copies of the Licensed Interest Documents including the
                  Licences;

         7.1.18   with respect to periods from and after the Economic Date,
                  Seller has not cancelled, waived, released, or discounted any
                  rights or claims under the Licences or the other Licensed
                  Interest Documents;

         7.1.19   there are no pre-emptive or preferential purchase rights held
                  by third parties with respect to all or any portion of the
                  Interests; and

         7.1.20   so far as Seller is aware, the Historical Data is true and
                  accurate in all material respects to the extent that it is
                  historical and factual in content, and was produced in good
                  faith at the time that it was created.

         The warranties set out above shall be deemed to be repeated at
         Completion with the exception of the warranties set out in paragraph
         1.4 of Part 2 of Schedule 5 and paragraph 7 of Schedule 6 and in
         clauses 7.1.3(b), 7.1.4(c), 7.1.4(d), 7.1.6, 7.1.7, 7.1.8(b), 7.1.12,
         7.1.13, 7.1.14(b), 7.1.15 and 7.1.20.

         The only Warranty given by Seller in respect of Environmental
         Liabilities is that set out in clause 7.1.13 and none of the other
         Warranties shall be deemed given in relation to Environmental
         Liabilities.

7.2      Subject to the provisions of this clause 7 and save as otherwise
         expressly disclosed in writing to Seller, Purchaser hereby warrants to
         Seller as of the date hereof and as of the Completion Date as follows:


                                      -26-

         7.2.1    Purchaser is duly incorporated with limited liability and
                  validly existing under the laws of England and Wales;

         7.2.2    the documents which contain or establish Purchaser's
                  constitution incorporate provisions which authorise, and all
                  necessary corporate action has been taken to authorise,
                  Purchaser to execute and deliver this Agreement and perform
                  the transactions contemplated hereby;

         7.2.3    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 any provision
                  contained in any agreement, instrument, law, judgment, order,
                  licence, permit or consent by which Purchaser or any of its
                  Affiliates or any of its assets is bound or affected; and

         7.2.4    no litigation, arbitration, administrative proceeding, dispute
                  or judgment against Purchaser or to which Purchaser is a party
                  which might by itself or together with any such other
                  proceedings have a material adverse effect on its business,
                  assets or condition and which would materially and adversely
                  affect its ability to observe or perform its obligations under
                  this Agreement and the transactions contemplated hereby, is
                  subsisting or, so far as Purchaser is aware, threatened or
                  pending against Purchaser or any of its assets.

7.3      Each warranty set out in clauses 7.1 and 7.2 shall be construed as a
         separate warranty.

7.4      Seller shall not be liable for any Relevant Claim in relation to any
         breach of any Warranty unless it shall have received from Purchaser, as
         soon as practicable after Purchaser becomes aware of the same, written
         notice containing reasonable details of the Relevant Claim including
         Purchaser's provisional estimate of the amount of the Relevant Claim.
         The failure of Purchaser to give prompt notice of a Relevant Claim
         shall not relieve Seller of its obligations under this Agreement except
         to the extent such failure prejudices Seller's ability to defend
         against the Relevant Claim; provided always that unless such notice is
         received on or before 18 months after the Completion Date Seller shall
         have no liability for such Relevant Claim. Any Relevant Claim made
         shall be deemed to have been withdrawn unless proceedings in respect
         thereof have been both issued and served on Seller within 6 months of
         the giving of such notice.

7.5      Except as set out in clause 7.1, neither Seller nor any of its
         Affiliates nor any officer, shareholder, director, employee, agent,
         consultant or representative of Seller or any of its Affiliates
         (including, without limitation, their auditors) makes any
         representation, warranty, statement, opinion, information or advice
         (including without limitation any representation, warranty, statement,
         opinion, information or advice (a) communicated (orally or in writing)
         to Purchaser or any Affiliate of Purchaser or (b) made in any data,
         information or document communicated to Purchaser or any Affiliate of
         Purchaser or made by any officer, shareholder, director, employee,
         agent, consultant or representative of Seller or any Affiliate of
         Seller) and Purchaser acknowledges, affirms and warrants that it has
         not relied,


                                      -27-

         and will not rely, upon such representation, warranty, statement,
         opinion, information or advice of any person in entering into this
         Agreement or carrying out the transactions contemplated by this
         Agreement. Without limiting the generality of the foregoing, Seller
         does not make any representation or warranty as to: (i) the amounts,
         quality or deliverability of reserves of crude oil, natural gas or
         other hydrocarbons attributable to the Interests, (ii) any geological,
         geophysical, engineering, economic or other interpretations, forecasts
         or evaluations, (iii) any forecast of expenditures, budgets or
         financial projections, (iv) any geological formation, drilling prospect
         or hydrocarbon reserve, or (v) the state, condition or fitness for
         purpose of any of the physical assets, including installations,
         pipelines and plant and machinery, which comprise the Interests.

7.6      The liability of Seller in respect of any Relevant Claim shall be
         limited as follows:

         7.6.1    there shall be disregarded for all purposes, including for the
                  avoidance of doubt clause 7.6.2, any Relevant Claim in respect
                  of which claim the amount of the damages to which the
                  Purchaser would otherwise be entitled is less than $1,000,000
                  (one million Dollars);

         7.6.2    Seller shall not have any liability except and only to the
                  extent that the damages to which Purchaser is entitled in
                  aggregate exceed $15,000,000 (fifteen million Dollars); and

         7.6.3    the maximum aggregate liability of Seller in respect of all
                  claims for breach of the representations and warranties shall
                  not exceed an amount equal to one hundred and ten per cent. of
                  the Consideration.

7.7

         7.7.1    Without prejudice to Purchaser's rights under this Agreement
                  and subject always to clause 7.2.2, if Purchaser receives
                  written notice of any claim from a third party which may give
                  rise to Purchaser having a Relevant Claim against Seller and
                  Purchaser duly notifies Seller of such Relevant Claim pursuant
                  to clause 7.4, Purchaser shall as soon as practicable notify
                  Seller of that third party claim in writing (a "THIRD PARTY
                  CLAIM"). If requested by notice in writing by Seller within 20
                  Business Days of receipt by Seller of the notice from
                  Purchaser of the Third Party Claim, Purchaser shall:

                  (a)     use reasonable endeavours to defend such Third Party
                          Claim; and

                  (b)     keep Seller reasonably informed with respect to the
                          process of such Third Party Claim,

                 and Seller shall be entitled to take and/or require Purchaser
                 to take any reasonable action to resist such claim (but at
                 Seller's sole cost and expense) and Seller shall have the
                 conduct of any appeal, dispute, compromise or defence of such
                 Third Party Claim and Purchaser shall give Seller all
                 co-operation, access and assistance for the purposes of


                                      -28-

                 considering and resisting such Third Party Claim as Seller may
                 reasonably require.

         7.7.2    Notwithstanding clause 7.7.1, Seller shall not be entitled to
                  take any action or do anything in the name of Purchaser and
                  Purchaser shall not be obliged to take any action or do
                  anything requested of it by Seller:

                  (a)     if and to the extent that the:

                          (i)      Purchaser is or would be likely to be
                                   commercially prejudiced to a material extent
                                   in Purchaser's opinion (acting reasonably);

                          (ii)     reputation of Purchaser, or the reputation of
                                   any of its Affiliates may, in the opinion of
                                   Purchaser (or its relevant Affiliates),
                                   (acting reasonably), be likely to be damaged
                                   or impaired;

                  (b)     unless Purchaser is indemnified by Seller to
                          Purchaser's reasonable satisfaction for all
                          liabilities, damages or losses and for all costs and
                          expenses which Purchaser (or any of its Affiliates)
                          may incur or suffer in respect of the defence, action,
                          act, thing, co-operation, access and assistance
                          required or requested of Purchaser under clause 7.7.1.

7.8      If Seller pays to Purchaser an amount pursuant to a Relevant Claim and
         Purchaser is entitled to recover from some other person any sum to
         which it would not have been or become entitled but for the
         circumstances giving rise to such Relevant Claim, subject to being put
         in funds to the reasonable satisfaction of the Purchaser, Purchaser
         shall promptly undertake all appropriate steps to enforce such recovery
         and shall as soon as practicable following any such recovery repay to
         Seller the lesser of: (i) the amount paid to it by the relevant Seller
         pursuant to the Relevant Claim; and (ii) the amount recovered from the
         third party in each case less all costs, charges and expenses
         reasonably incurred by Purchaser in obtaining (or consequent upon
         obtaining) that payment and in recovering that amount from the third
         party.

7.9      The Seller shall not be liable for any Relevant Claim if and to the
         extent that such Relevant Claim:

         7.9.1    occurs or arises or, such Relevant Claim otherwise having
                  arisen, is increased as a result of any act, matter, omission,
                  transaction or circumstance which would not have occurred but
                  for, the passing of, or any change in, after the date hereof,
                  any law, rule, regulation, interpretation of the law or any
                  administrative practice of any government, governmental
                  department, agency or regulatory body, including any passing
                  of or change in any law, rule, regulation, interpretation of
                  the law or any administrative practice as aforesaid which
                  takes effect retrospectively, or any increase in the rates of
                  Tax or any imposition of Tax or any amendments to or the
                  withdrawal of any extra-statutory concession or other practice
                  previously made by or


                                      -29-

                  published by the Inland Revenue or other taxing authority (in
                  whatever jurisdiction) and in force at the date of this
                  Agreement;

         7.9.2    occurs or arises or, such Relevant Claim otherwise having
                  arisen, is increased as a result of anything voluntarily done
                  or omitted to be done between the date of this Agreement and
                  the Completion Date by Seller with the Purchaser's prior
                  written consent (provided that Seller shall have acted as a
                  reasonable and prudent operator and in accordance with
                  generally accepted oilfield practices in the UKCS), or at
                  Purchaser's prior written request;

         7.9.3    occurs or arises or, such Relevant Claim otherwise having
                  arisen, is increased as a result of any voluntary act,
                  default, omission, transaction or arrangement after Completion
                  by the Purchaser, in the ordinary course of its business as
                  now carried on.

7.10     Nothing in this Agreement shall relieve Purchaser of any duty, whether
         at common law or otherwise, to mitigate any loss or damage incurred by
         it in respect of any breach by the Seller of the representations,
         warranties, indemnities or any other term of this Agreement or in
         respect of its subject matter.

7.11     Purchaser shall not be entitled to recover from Seller the same sum or
         loss more than once in respect of any Relevant Claim.

7.12     Seller shall not be liable in respect of any Relevant Claim to the
         extent that a provision or reserve has been or will be made in
         calculating the Adjustments in respect of the matter or transaction
         giving rise to such Relevant Claim.


8.       ONGOING OBLIGATIONS AND LIABILITIES

8.1      Following the Completion Date, Purchaser shall assist and co-operate
         with Seller in endeavouring to obtain from the relevant authorities an
         irrevocable release of Seller from its obligations and liabilities
         under the Petroleum Act 1998 or other relevant statute, regulations,
         order from any competent authority or guidelines and all notices and
         regulations served and issued pursuant thereto, insofar as the same
         relate to the Interests. Without prejudice to the foregoing, if,
         following the Completion Date, the Secretary requires that Seller
         prepare and implement a programme or requirement for or in respect of
         any part of the Decommissioning Liabilities, whether pursuant to the
         terms of the Petroleum Act 1998 or other relevant statute, regulations,
         order from any competent authority or guidelines, Seller shall notify
         Purchaser, and Seller and Purchaser shall prepare and implement such
         programme or requirement in accordance with the requirements of the
         Petroleum Act 1998 or other relevant statute, regulation, order or
         guidelines, as the case may be, and all other relevant statutes,
         regulations, orders and guidelines and the indemnity in clause 6.6
         shall extend to all Losses and Expenses incurred by or on behalf of the
         Seller in the preparation and implementation of such programme.

8.2      Seller and Purchaser agree that the provisions of Parts 1 of Schedules
         5 and 6 shall have effect in relation to the Employees.


                                      -30-

8.3      Simultaneously with the execution of this Agreement the Purchaser shall
         procure the delivery to the Seller of the Purchaser's Guarantee. If
         following the date of this Agreement a company other than the parent
         company of the Purchaser which executes the Purchaser's Guarantee
         becomes the ultimate parent company of the Purchaser then the Purchaser
         will forthwith procure the delivery to the Seller of an additional
         parent company guarantee in the form of the Purchaser's Guarantee save
         for the designation of the parent company therein.

8.4      Following Completion, Seller agrees, if requested by Purchaser, to use
         reasonable endeavours to continue to provide office accommodation and
         ongoing office support services for the Employees and (if different)
         the Transition Team representatives of Purchaser, at the sole risk and
         cost of Purchaser for a period not exceeding two months.


9.       CONFIDENTIALITY AND ANNOUNCEMENTS

9.1      Without prejudice to the terms of the confidentiality agreement entered
         into between BP America Production Company and Apache Corporation dated
         5 December 2002 (as amended by a deed of variation dated 11 December
         2002), the terms of this Agreement and all information furnished or
         disclosed to Purchaser or any of its Affiliates in connection with the
         transactions contemplated by this Agreement ("Confidential
         Information") shall be held confidential by the Parties and shall not
         be divulged in any way by a Party to any third party without the prior
         written approval of each of the other Parties provided that any Party
         may, without such approval, disclose such Confidential Information to:

         9.1.1    any outside professional consultants, upon obtaining a similar
                  undertaking of confidentiality (but excluding this proviso)
                  from such consultants;

         9.1.2    any bank or financial institution from whom such Party is
                  seeking or obtaining finance, upon obtaining a similar
                  undertaking of confidentiality (but excluding this proviso)
                  from such bank or institution;

         9.1.3    the extent required by any applicable laws or the requirements
                  of any recognised stock exchange in compliance with its rules
                  and regulations;

         9.1.4    any department, authority, ministry or agency of any
                  government or other governmental authority lawfully requesting
                  such information;

         9.1.5    any Court or arbitral tribunal of competent jurisdiction
                  acting in pursuance of its powers;

         9.1.6   any of its Affiliates upon obtaining a similar undertaking of
                  confidentiality from such Affiliates;

         9.1.7    Standard & Poor's, Moody's or any other rating agency, but
                  only if the confidential nature of the Confidential
                  Information is disclosed to such rating agency;


                                      -31-

         9.1.8    in the case of Purchaser, to its lead and co-lead underwriters
                  formally engaged by it to serve as advisors (collectively, the
                  "Financial Advisers") in connection with the underwritten
                  public offering of securities being undertaken by Purchaser to
                  provide funding in connection with this Agreement and the
                  agreement between the Parties' Affiliates in the United States
                  in respect of certain oil and gas properties and leases in the
                  U.S. Gulf of Mexico Outer Continental Shelf ("Transactions").
                  Such Confidential Information may be disclosed to employees of
                  the Financial Advisers only if and to the extent that such
                  employees need to know such Confidential Information.
                  Purchaser shall inform each Financial Institution of the
                  confidential nature of the Confidential Information and the
                  requirement that it not be used for any purpose other than the
                  underwriting of the Transactions. Each Financial Institution
                  shall be required to execute a written undertaking of
                  confidentiality, as a condition of receiving Confidential
                  Information; or

         9.1.9    insurers (including insurance brokers) but only if the
                  confidential nature of the Confidential Information is
                  disclosed to such person.

9.2      However, the undertaking of confidentiality above shall not extend to
         any Confidential Information which is:

         9.2.1    generally available to the public other than as a result of a
                  wrongful disclosure by Purchaser;

         9.2.2    available to Purchaser as owner of, or where the Purchaser is
                  otherwise entitled to, such information without any
                  restriction or disclosure; or

         9.2.3    available to Purchaser on a non-confidential basis from a
                  source other than Seller if such source is entitled to
                  disclose such information.

9.3      No party or its Affiliate shall make any public announcement or
         statement about this Agreement or its contents containing new
         information without first having obtained the prior written consent of
         the other Party, such consent not to be unreasonably withheld or
         delayed. Notwithstanding the previous sentence and clause 9.1, no prior
         written approval of a Party shall be required for public announcements
         where it is necessary for the other Party or its Affiliate to make such
         public announcement or statement in order to comply with a statutory
         obligation, an obligation to include information in published or
         audited accounts, or with the requirement of a competent government
         agency, The London Stock Exchange, the UK Listing Authority or other
         regulatory body, or a recognised stock exchange on which that Party or
         such Affiliate has its shares or oil production or royalty stock
         listed, in which event the Party proposing to make such an announcement
         or statement shall, where reasonably practicable, issue a copy thereof
         to the other Party prior to its release.

9.4      If Completion does not take place for any reason provided for in this
         Agreement Purchaser shall remain bound by this clause 9,
         notwithstanding any termination of this Agreement, until the earlier of
         the fifth anniversary of such termination or such time as it has
         entered into a separate undertaking of confidentiality on the


                                      -32-

         same or similar terms in respect of such information (and this clause
         9.4 shall also survive until such time).

9.5      If this Agreement is terminated as aforesaid, Purchaser shall, at the
         request of the Seller, promptly return to Seller (and delete from
         Purchaser's systems, where electronically stored) all Confidential
         Information.

9.6      If Completion does take place, the undertaking of confidentiality
         contained herein shall be superseded by the confidentiality provisions
         in the Licensed Interest Documents and shall be of no further effect to
         the extent that the Confidential Information falls within the category
         of data and information which is the subject thereof.


10.      NOTICES

10.1     Except as otherwise provided in this Agreement any notice or other
         document to be given under this Agreement shall be in writing and shall
         be deemed to be duly given if it (or the envelope containing it)
         identifies the Party to whom it is intended to be given as the
         addressee and:

         10.1.1  it is delivered personally; or

         10.1.2   it is sent by (i) first class post or express or other fast
                  postal service or (ii) the recorded delivery service or (iii)
                  facsimile transmission to the respective addresses shown below
                  or to such other addresses and/or numbers as such Parties may
                  by notice to all other Parties hereto expressly substitute
                  therefor;

                  when in the ordinary course of the means of transmission it
                  would first be received by the addressee in normal business
                  hours. The respective addresses for service are:

                  Seller:

                  Address:        BP Exploration Operating Company Limited
                                  Burnside Road
                                  Farburn Industrial Estate
                                  Dyce
                                  Aberdeen AB21 7PB

                  Attention:      Business Unit Leader
                                  Mid North Sea Business Unit

                  Facsimile:      01224 834800

                  Purchaser:

                  Address:        c/o Herbert Smith
                                  Exchange House

                                      -33-

                                  Primrose Street
                                  London EC2A 2HS

                  Attention:      Henry Davey and Paul Griffin

                  Facsimile       020 7374 0888

                  With a copy to: Apache Corporation
                                  2000 Post Oak Boulevard
                                  Suite 100
                                  Houston
                                  Texas 77056-4400
                                  United States of America

                  Attention:      Lisa A. Stewart,
                                  Executive Vice-President,
                                  Business Development

                  Facsimile:      +(1) (713) 296 6459

10.2     In proving the giving of a notice it shall be sufficient to prove that
         the notice was left or that the envelope containing such notice was
         properly addressed and posted or that the applicable means of
         telecommunications was properly addressed and despatched (as the case
         may be).

10.3     Any notice duly given within the meaning of clause 10.1 shall be deemed
         to have been both given and received:

         10.3.1   if it is delivered in accordance with clause 10.1.1, on such
                  delivery;

         10.3.2   if it is duly posted or transmitted in accordance with clause
                  10.1.2 by any of the methods there specified, on the second
                  Business Day after the day of posting or (in the case of a
                  notice transmitted by facsimile transmission) upon receipt by
                  the sender of the correct transmission report.

10.4     For the purposes of this clause 10 "notice" shall include any request,
         demand, instructions or other document.


11.      COSTS AND EXPENSES

11.1     Save as stated in clause 11.3, Seller and Purchaser shall each pay its
         and its Affiliates' own costs, expenses, duties and, except as
         otherwise expressly agreed in writing, taxation in relation to the
         preparation and execution of this Agreement, the documents contemplated
         hereby or executed pursuant hereto.

11.2     Without prejudice to any other rights hereunder, if any amount payable
         hereunder is not paid when due, the defaulting Party shall pay interest
         on such amount from the due date of payment (after as well as before
         judgment) at a rate equal to three per cent (3%) above the Agreed Rate
         calculated on a compounded basis on the


                                      -34-

         accumulated daily balances. The Parties agree that this constitutes a
         substantial contractual remedy.

11.3     Subject to the terms of the stamp duty agreement between Seller and
         Purchaser of even date herewith, Purchaser shall be responsible for
         payment in a timely fashion of any and all stamp duties and charges
         payable on or in respect of this Agreement, the Completion Documents,
         any related agreements and in respect of its or their subject matter
         and any similar duties and charges wheresoever arising.


12.      TAXATION

12.1

         12.1.1   Purchaser warrants that prior to Completion it will be
                  registered for VAT in the United Kingdom and that it intends
                  to use the Interests for its own trade of
                  exploration/exploitation.

         12.1.2   Seller warrants that it is registered for VAT in the United
                  Kingdom.

12.2

         12.2.1   Seller has incurred qualifying expenditure and/or has an
                  amount of residue of expenditure in respect of mineral
                  exploration and access allocations (as defined for the
                  purposes of the Capital Allowances Act 2001) on each of (i)
                  plant and machinery relating to the Interests and (ii) mineral
                  exploration and access to which Consideration is allocated
                  under Schedule 2 of an amount in respect of each such item at
                  least equal to the amount so allocated to that item.

         12.2.2   Seller has complied in all material respects with obligations
                  relating to PAYE as they apply to the Employees.

         12.2.3   Seller has kept and maintained proper books and records in
                  respect of the Interests to the extent required by applicable
                  United Kingdom taxation laws (including those books and
                  records relevant to VAT and PRT) and to the extent necessary
                  to enable Purchaser to comply with its United Kingdom tax
                  obligations or to obtain tax rebates or other tax benefits in
                  respect of the Interests, has made available to Purchaser
                  copies of such books and records.

12.3     Purchaser undertakes that it will use the Interests acquired as part of
         its going concern for a sufficient period to comply with the
         requirements of Article 5 of the Value Added Tax (Special Provisions)
         Order 1995, so that the transfer thereof is neither a supply of goods
         nor a supply of services for VAT purposes.

12.4     The Parties believe that the transfer hereunder is a transaction which
         is outside the scope of VAT by virtue of Article 5 of the Value Added
         Tax (Special Provisions) Order 1995 and/or that the transfer
         contemplated hereby is of a right over land situated outside the United
         Kingdom and as such will be treated as outside the scope of Value Added
         Tax by virtue of Article 5 of the Value Added

                                      -35-

         Tax (Place of Supply of Services) Order 1995. However, if Seller is
         advised in writing by HM Customs and Excise that such transaction is
         subject to VAT, Seller shall promptly inform Purchaser and shall
         co-operate with Purchaser as Purchaser may reasonably request and at
         Purchaser's cost to persuade HM Customs and Excise that such
         transaction is not subject to VAT. In any event, Purchaser undertakes
         to pay to Seller, on delivery of a valid VAT invoice, any amounts due
         in respect of VAT within thirty (30) days of demand.

12.5     The Parties agree that Seller shall make application to the HM Customs
         and Excise under section 49(1)(b) of the Value Added Tax Act 1994 for a
         direction that the records relating to the Interests which under
         paragraph 6 Schedule 11 to the Value Added Tax Act 1994 have been
         maintained by Seller should be preserved by Seller notwithstanding the
         provisions of the said section. Seller shall forthwith upon receipt
         thereof provide the Purchaser with a copy of any such direction, and
         Purchaser shall retain access at all reasonable times during normal
         business hours to all books and records retained by Seller or its
         Affiliates in relation to VAT matters concerning the Interests, and
         Seller covenants to retain such records as required by paragraph 6
         Schedule 11 to the Value Added Tax Act 1994.

12.6     Seller confirms that no election has been made and that no election
         will be made prior to the Completion Date under paragraph 2, Schedule
         10 to the Value Added Tax Act 1994 in relation to any of the Interests.

12.7     Reimbursements pursuant to clause 3 (Adjustments) shall be exclusive of
         VAT which Seller may be required to charge and, if called upon to do so
         by Seller, Purchaser undertakes to pay Seller on presentation of a VAT
         invoice any amounts properly due in respect of VAT set out in such
         invoice within thirty (30) days of demand.

12.8     Subject to clause 12.4 above, any adjustments pursuant to clause 3,
         clause 6.4 or clause 7 in respect of any payment or receipt being an
         amount in respect of which VAT has been paid or received shall be made
         on a basis disregarding the VAT element where the VAT paid is fully
         deductible or is required to be accounted for in full to HM Customs &
         Excise, but otherwise shall be made on a basis which leaves Seller in
         no better and no worse a position (after taking account of VAT, and
         subject to the application of the other provisions of this clause 12)
         than had the payment or receipt not been made or received.

12.9     In relation to each part of the Interests being an interest in an oil
         field (within the meaning of Schedule 1 to the Oil Taxation Act 1975),
         Seller shall prepare and Purchaser and Seller shall deliver to the
         Board of Inland Revenue in a timely fashion a notice under paragraph 3
         of Schedule 17 Finance Act 1980, and shall not make application under
         paragraph 4 of the said Schedule for the provisions of Parts II and III
         of the Schedule not to apply.

12.10    The Parties acknowledge that in the periods up to Completion Seller may
         have incurred expenditure in relation to some or all of the Fields
         which can be claimed for PRT purposes under either Schedule 5 or 6 to
         the Oil Taxation Act 1975. Seller shall take all actions and do all
         things reasonably in its power to ensure that


                                      -36-

         any such expenditure is claimed and, in particular, Seller shall
         prepare and sign all Schedule 6 claims in respect of such expenditure
         and provide copies of the same to Purchaser on or before Completion.

12.11    Seller and Purchaser agree that the allocation with respect to the
         Interests set out in Schedule 2 is a just apportionment of the
         Consideration. Seller and Purchaser agree that they will each present
         their returns for tax purposes on the basis of said allocation and that
         they will use all reasonable endeavours to agree with the OTO the
         figures so presented.

12.12    Seller and Purchaser acknowledge that, except as provided in clause
         12.13 below, the Consideration represents expenditure incurred by the
         Purchaser in acquiring plant and machinery relating to the Interests
         only to the extent shown by the allocations set out in Schedule 2.
         Seller covenants that it will treat the said allocated expenditure on
         plant and machinery as disposal proceeds for the purposes of sections
         60 and 61 of the Capital Allowances Act 2001, and Purchaser covenants
         that it will treat such amount as capital expenditure incurred for the
         purposes of Part 2 of the Capital Allowances Act 2001.

12.13    Insofar as the Consideration is increased pursuant to clause 3, clause
         6.4 or clause 7 by reference to expenditure qualifying for capital
         allowances under Part 2 of the Capital Allowances Act 2001 incurred by
         Seller, the allocation of the Consideration to expenditure incurred by
         Purchaser in relation to the relevant part of the Interests in
         acquiring plant and machinery, as set out in Schedule 2, shall be
         increased by a corresponding amount.

12.14    Seller and Purchaser acknowledge that it is not just and reasonable to
         attribute any part of the Consideration to allowable scientific
         research expenditure of a capital nature or mineral exploration and
         access except to the extent of the amounts set out in Schedule 2, and
         Seller and Purchaser undertake to submit to the Inland Revenue
         computations of liability to CT on that basis and not on any basis
         which is inconsistent therewith; and for the purposes of this
         paragraph, the expression "mineral exploration and access" shall have
         the same meaning as in Part 5 of the Capital Allowances Act 2001.

12.15    Seller and Purchaser acknowledge that the Consideration is in respect
         of expenditure incurred by Purchaser on the construction of industrial
         buildings or structures within the meaning of Part 3 of the Capital
         Allowances Act 2001 only to the extent shown by the allocations set out
         in Schedule 2. Seller and Purchaser undertake to submit to the Inland
         Revenue computations of liability to CT on the basis that such
         allocations represent the sale moneys for the purposes of Part 3,
         Chapter 7 of the Capital Allowances Act 2001.

12.16    For the avoidance of doubt no part of the Consideration payable by
         Purchaser to Seller falls to be treated as intangible drilling costs on
         production wells qualifying for relief under Part 5 of the Capital
         Allowances Act 2001.

12.17    Seller shall be liable for any liabilities arising under Schedule 15 to
         the Finance Act 1973 in respect of the Interests for periods ending
         prior to the Economic Date, and Purchaser shall be liable for all
         periods thereafter.


                                      -37-

12.18    Subject to clause 12.24, if any liability for or right to repayment of
         PRT in connection with the Interests which relates to the period of
         ownership prior to the Economic Date of Seller arises after the
         Economic Date and the adjustment giving rise to such liability or right
         is in respect of income and expenditure of Seller during such period of
         ownership then the liability or repayment shall be the responsibility
         or entitlement of Seller. Any repayment of PRT in connection with the
         Interests arising otherwise than in respect of Seller's period of
         ownership prior to the Economic Date shall be the entitlement of the
         Purchaser.

12.19    Notwithstanding any other provision of this Agreement, Seller shall
         retain access to all books and records and operator information in
         relation to PRT income and expenditure claims under Schedules 5 and 6
         of the Oil Taxation Act 1975 in relation to the Interests for all
         periods ended prior to the Completion Date. Purchaser shall, as soon as
         reasonably practical, ensure that all documentation relating to any PRT
         assessments, returns or claims issued by the Inland Revenue or
         Operators in respect of such periods, is communicated to Seller without
         unreasonable delay.

12.20    The Parties agree that all adjustments to Licence Royalty whether
         increases or decreases will be payable or receivable by Seller.

12.21    PRT ADJUSTMENTS

         The following provisions of this clause 12.21 are subject to the
         provisions of clause 12.26.

         12.21.1  The Consideration shall be increased by Purchaser paying to
                  Seller the following sums:

                  (a)     a sum equal to the amount of any PRT instalment paid
                          by Seller in relation to the Interests under paragraph
                          2, Schedule 19 to the Finance Act 1982 which, by
                          virtue of paragraph 2(3) of the said Schedule, is
                          regarded as a payment of PRT in respect of any
                          Chargeable Period beginning on or after the Economic
                          Date. Seller undertakes to withhold payment of such
                          PRT instalments in accordance with paragraph 3 of said
                          Schedule if the relevant conditions are met;

                  (b)     a sum equal to any amount of PRT assessed on, and paid
                          by Seller in relation to the Interests, for any
                          Chargeable Period mentioned in (a) above less amounts
                          already paid by Purchaser under this paragraph (a)
                          above.

                  For the purpose of calculating any sums due under paragraph
                  (b) above, PRT assessed on, and paid by Seller for the
                  Chargeable Period including the Economic Date shall be
                  recalculated to exclude any amounts brought into the
                  assessment under section 2(4)(b) of the Oil Taxation Act 1975.

                  For the purposes of calculating any sums due under paragraph
                  (b) above the PRT assessed on, and paid by Seller for the
                  Chargeable Period including the Economic Date or any
                  subsequent Chargeable Period shall


                                      -38-

                  be recalculated to exclude any amounts brought into the
                  assessment under section 2(6)(b) of the Oil Taxation Act 1975.

                  (c)     a sum equal to any effective PRT relief received by
                          Purchaser, in relation to the Interests, either by way
                          of a refund of PRT or a reduction in PRT due, in
                          respect of any expenditure incurred by Seller prior to
                          the Economic Date; and

                  (d)     a sum equal to any effective PRT relief received by
                          Purchaser, in relation to the Interests, either by way
                          of a refund of PRT or a reduction in PRT due in
                          respect of expenditure incurred by Seller after the
                          Economic Date which does not relate to the Interests.

                  Seller and Purchaser shall use all reasonable endeavours to
                  persuade the OTO that PRT relief in respect of the expenditure
                  referred to in (d) above should be received by Seller and not
                  Purchaser.

                  Purchaser and Seller recognise that amendments of assessments
                  to PRT may arise and to the extent that any amendment gives
                  rise to overpayments having been paid by Purchaser to Seller
                  under this clause 12.21 Seller will promptly repay to
                  Purchaser, as a decrease in the Consideration on, any such
                  overpayment. Purchaser and Seller also recognise that sums
                  paid under paragraph (a) above may be in excess of the PRT
                  assessed on Seller in which case paragraph (b) above shall not
                  apply and Seller shall promptly pay to Purchaser, as a
                  decrease in the Consideration, any repayment made by the
                  Inland Revenue in respect of that excess.

         12.21.2  For the purposes of calculating any sums payable under clause
                  12.21.1, the calculation of PRT shall be modified as follows:
                  To the extent that clause 3.7.3 (Petroleum Sales Adjustment)
                  operates, such PRT calculation shall be based on the amounts
                  so amended by clause 3.7.3 and not the petroleum revenue
                  included in the PRT return for the relevant sales.

         12.21.3

                  (a)     Increases to the Consideration arising under clauses
                          12.21.1(a) and 12.21.1(b) above shall be due for
                          payment within thirty (30) days of Seller submitting
                          reasonable documentary evidence to Purchaser in
                          support of any request for payment.

                  (b)     Increases to the Consideration arising under clauses
                          12.21.1(c) and 12.21.1(d) above shall be due for
                          payment within thirty (30) days of Purchaser having
                          received effective PRT relief.

                  (c)     Decreases to the Consideration arising under the last
                          paragraph of clause 12.21.1 above shall be due for
                          payment within thirty (30) days of Seller receiving
                          any PRT refund or within thirty (30) days of Purchaser
                          having paid any PRT as the case may be.


                                      -39-

         12.21.4  To the extent that Seller has a PRT liability arising in
                  respect of a Chargeable Period within the Interim Period and
                  expenditure relief for that Chargeable Period has been
                  transferred to Purchaser under Paragraph 6 Schedule 17 Finance
                  Act 1980 then, at the request of Seller, Purchaser and Seller
                  shall jointly elect under Paragraph 14 Schedule 17 Finance Act
                  1980 to transfer the loss from Purchaser to Seller.

12.22    CT ADJUSTMENTS

         The provisions of this clause 12.22 are subject to the provisions of
clause 12.26.

         12.22.1  The Consideration shall be increased by Purchaser paying to
                  Seller an amount equal to Notional CT paid by Seller on any
                  income or other receipts taken into account for the purposes
                  of clause 3.

         12.22.2  The Consideration shall be decreased by Seller paying to
                  Purchaser an amount equal to:

                  (a)     Notional CT relief received by Seller on:

                          (i)      any cash calls paid and taken into account
                                   for the purposes of clause 3 (but excluding
                                   any expenditure which qualifies for capital
                                   allowances pursuant to clause 12.13);

                          (ii)     any expenditure taken into account for the
                                   purposes of clause 3 (but excluding any
                                   expenditure which qualifies for capital
                                   allowances pursuant to clause 12.13); and

                          (iii)    any PRT paid, net of any PRT repayments
                                   received by Seller and taken into account for
                                   the purposes of clauses 12.21.1(a) and
                                   12.21.1(b); and

                  (b)     Notional CT paid by Purchaser on, or arising from the
                          effective PRT relief received by Purchaser and
                          referred to under clauses 12.21.1(c) and (d).

         12.22.3  The Parties recognise that adjustments to the Consideration
                  under this clause 12.22 are notional adjustments, as opposed
                  to actual payments of, reliefs from or reductions in CT
                  liabilities. For the purpose of calculating the Notional CT it
                  shall be assumed that both Seller and Purchaser are single
                  companies with no brought forward losses who are paying CT at
                  the standard rate applicable for the period concerned and that
                  the Notional CT includes the Supplementary Charge to ring
                  fence trades. Such notional adjustments shall be effected by
                  deducting from each relevant payment a Notional CT charge.


                                      -40-

12.23    INTEREST ON LATE PAYMENT OF PRT

         12.23.1  The Consideration shall be increased by Purchaser paying to
                  Seller a sum equal to any interest charged to Seller under
                  paragraph 15 of Schedule 2 to the Oil Taxation Act 1975, in
                  respect of PRT in relation to the Interests for Chargeable
                  Periods beginning on or after the Economic Date provided that
                  the underpayment of PRT giving rise to the interest charge was
                  not caused by the wilful default or neglect of Seller.
         12.23.2  The Consideration shall be decreased by Seller paying to
                  Purchaser a sum equal to any interest received by Seller under
                  paragraph 16 of the Schedule 2 to the Oil Taxation Act 1975 in
                  respect of PRT in relation to the Interests for Chargeable
                  Periods beginning on or after the Economic Date.

                  Adjustments to Consideration under this clause 12.23 shall be
                  made within 30 days of Seller having received any PRT interest
                  or having paid any PRT interest, as the case may be.

12.24    Should Seller receive any PRT refund as a result of a loss incurred by
         Purchaser pursuant to the provisions of paragraph 15 of Schedule 17 to
         the Finance Act 1980, Seller shall within ten Business Days pay
         Purchaser an amount equal to the PRT refund together with any interest
         thereon less any CT payable by Seller on such refund and/or such
         interest and less any interest on such CT payable.

12.25    INFORMATION

         12.25.1  Seller shall provide Purchaser in a timely fashion with copies
                  of all records and tax returns relating to periods prior to
                  the Completion Date and relating wholly or partly to the
                  Interests which are reasonably required by Purchaser for the
                  purposes of completing and filing any tax return.

         12.25.2  Each Party shall use its reasonable endeavours to provide
                  written advice to the other Party of any event giving rise to
                  an adjustment under clause 6.4 within thirty (30) days of
                  becoming aware of such an event. This advice will include a
                  copy of such documentary evidence, as is reasonably deemed to
                  be necessary by the other Party, to verify the adjustment.

         12.25.3  Seller shall prepare and submit on a timely basis to the OTO
                  all claims reasonably possible under Schedule 6 to the Oil
                  Taxation Act 1975 in respect of qualifying expenditure
                  incurred by Seller from the Economic Date.

12.26    Seller and Purchaser agree that the overriding principle in respect of
         PRT adjustments and CT adjustments as provided for in clauses 12.21 and
         12.22 is to put the Parties in the same position as they would have
         been in had Completion taken place on the Economic Date.


                                      -41-

12.27    INDEPENDENT DETERMINATION

         If the Parties cannot reach agreement on the contents of all or part of
         the adjustments referred to in clauses 12.21 and/or 12.22 within thirty
         (30) Business Days of receipt by Purchaser from Seller of Seller's
         estimate of such adjustments, the adjustments in dispute may be
         referred by any Party for determination by an independent expert
         nominated by the Parties or, in the absence of agreement between the
         Parties within five (5) Business Days of a Party notifying the other
         that it proposes to refer the dispute to an expert, by the President of
         the Institute of Chartered Accountants in England and Wales. Within
         twenty (20) Business Days after the appointment of such expert, each
         Party may submit to the expert a statement of the nature of the
         dispute, a description of the submitting Party's claims with respect
         thereto, and any other supporting documentation or materials with
         respect thereto that the submitting Party desires the expert to
         consider. The Party submitting such statement shall provide a copy
         thereof to the other Party, who shall have ten (10) Business Days from
         receipt thereof to submit an answering statement to the expert. The
         nominated expert shall be afforded such access to books, records,
         accounts and documents in the possession of the Parties as he may
         reasonably request, and he shall act as expert not as arbitrator. The
         said expert's determination shall, in the absence of fraud or manifest
         error or bias, be final and binding on the Parties, his fees and
         disbursements shall be borne by Seller as to one half and Purchaser as
         to the other half and each Party shall bear its own costs in respect of
         such reference.


13.      VARIATION

         The terms and conditions of this Agreement shall only be varied by an
         agreement in writing signed by each of the Parties and specifically
         referring to this Agreement.


14.      ASSIGNMENT

         None of the rights or the obligations of a Party under this Agreement
         are assignable without the prior written consent of the other Party.


15.      FURTHER ASSURANCE

15.1     The Seller shall, from time to time on being required to do so by the
         Purchaser, promptly and at the cost and expense of the Seller do or
         procure the doing of all such acts (including using reasonable
         endeavours to obtain copies of any documents of title in respect of the
         Interests which Seller has not delivered to Purchaser at Completion)
         and/or execute or procure the execution of all such documents in a form
         satisfactory to the Purchaser as the Purchaser may reasonably consider
         necessary for giving full effect to this Agreement (or to such parts of
         it as remain operative after termination) and securing to the Purchaser
         the full benefit of the rights, powers and remedies conferred upon the
         Purchaser in this Agreement.


                                      -42-

15.2     The Purchaser shall, from time to time on being required to do so by
         the Seller, promptly and at the cost and expense of the Purchaser do or
         procure the doing of all such acts and/or execute or procure the
         execution of all such documents in a form satisfactory to the Seller as
         the Seller may reasonably consider necessary for giving full effect to
         this Agreement (or to such parts of it as remain operative after
         termination) and securing to the Seller the full benefit of the rights,
         powers and remedies conferred upon it in this Agreement.


16.      GENERAL

16.1     If there is any conflict between the provisions of this Agreement and
         the provisions of the Completion Documents and/or the Post Completion
         Documents, the provisions of this Agreement shall prevail.

16.2     So far as it remains to be performed, this Agreement shall remain in
         full force and effect notwithstanding Completion.

16.3     No waiver by the Seller or Purchaser of any breach of a provision of
         this Agreement shall be binding unless made expressly and in writing
         and any such waiver shall relate only to the matter to which it
         expressly relates and shall not apply to any subsequent or other
         matter.

16.4     This Agreement represents the entire understanding, and constitutes the
         whole agreement in relation to its subject matter and supersedes any
         previous agreement between the Parties (or any of them) with respect
         thereto and, to the fullest extent practicable under the relevant law,
         and without prejudice to the generality of the foregoing, excludes any
         warranty, condition or other undertaking implied at law or by custom.

16.5     This Agreement may be executed in any number of counterparts and by the
         parties on different counterparts but shall not be effective until each
         Party has executed at least one counterpart. Each counterpart shall
         constitute an original of this Agreement but all the counterparts
         together shall constitute one and the same agreement.

16.6     This Agreement shall inure to the benefit of and be binding upon the
         respective successors and permitted assigns of the Parties.

16.7     Nothing in this Agreement shall be read or construed as excluding any
         liability or remedy in respect of fraud.


17.      RIGHTS OF THIRD PARTIES

         With the exception of the rights of the Seller's Affiliates to enforce
         the terms of clauses 3.14, 6.6 and 6.7, nothing in this Agreement is
         intended to confer on any person any right to enforce any term of this
         Agreement which that person would not have had but for the Contracts
         (Rights of Third Parties) Act 1999. The Parties may by agreement
         rescind or vary any term of this Agreement without the consent of any
         of the Seller's Affiliates.


                                      -43-

18.      GOVERNING LAW

         The construction validity and performance of this Agreement and all
         agreements executed pursuant hereto shall be governed by English law
         (other than choice of law rules) and the Parties hereby irrevocably
         submit to the exclusive jurisdiction of the English Courts.

AS WITNESS whereof this Agreement has been signed by the duly authorised
representatives of the Parties on the day and year first above written.



SIGNED for and on behalf of )
BP EXPLORATION OPERATING    )
COMPANY LIMITED             )

/s/



SIGNED for and on behalf of )
APACHE NORTH SEA LIMITED    )

/s/
                                      -44-