<PAGE>
 
                                                                     EXHIBIT 2.6


                 HER MAJESTY THE QUEEN IN RIGHT OF NEW ZEALAND

                                   as Vendor


                                    - and -


                     EDISON MISSION ENERGY TAUPO LIMITED 

                                 as Purchaser


                                    - and -


                             EDISON MISSION ENERGY

                                  as Guarantor


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                      AGREEMENT FOR THE SALE AND PURCHASE
                      OF SHARES IN CONTACT ENERGY LIMITED

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                    [LOGO OF SIMPSON GRIERSON APPEARS HERE]
<PAGE>
 
                               CONTENTS


  Clause      Heading

  l.          Interpretation                                    
  2.          Sale of the Shares                                
  3.          Purchase Price                                    
  4           Purchaser's Obligations                           
  5.          Settlement and Payment of the Purchase Price      
  6.          Conditions of Settlement                          
  7.          Warranties                                        
  8.          Pending Settlement                                
  9.          Restrictions                                      
  10.         Purchaser's Covenants                             
  11.         No Greater Rights                                 
  12          Guarantee and Indemnity                           
  13.         Expenses                                          
  14.         Delay in Exercise of Rights                       
  15.         Further Assurances and Post Settlement            
  16.         Amendments                                        
  17.         Assignment                                        
  18.         Notices                                           
  19.         Counterparts                                      
  20.         Governing Law                                     
  21.         Process Agent                                      


  SCHEDULE

  l.          Registered Holders             
                                             
  2.          Form of Letter of Credit       
                                             
  3.          Form of Indemnity              
                                             
  4.          Bidding Rules                  
                                             
  5.          Capital Expenditure Details    
                                             
  6.          Purchaser and Guarantor Details 
<PAGE>
 
     THIS AGREEMENT is dated                            1999

     BETWEEN:


     (1)  HER MAJESTY THE QUEEN IN RIGHT OF NEW ZEALAND acting by and through
          her MINISTER OF FINANCE and her MINISTER RESPONSIBLE FOR CONTACT
          ENERGY LIMITED (the "Vendor" or the "Crown"); and


     (2)  THE PURCHASER SPECIFIED IN SCHEDULE 6 (the "Purchaser");

     (3)  THE GUARANTOR SPECIFIED IN SCHEDULE 6 (the "Guarantor").

     RECITALS:


     A.  Contact Energy Limited (the "COMPANY") is a company registered under
         the Companies Act 1993 and has an issued share capital of 603,950,000
         ordinary shares each ranking pari passu in all respects (such shares
         representing the consolidated number of shares after a two for one
         consolidation occurring on or about 10 March 1999).

     B.  The Vendor is the beneficial owner of all of the issued shares in the
         Company, which are registered in the names of certain persons as set
         out in Schedule l.

     C.  The Vendor is willing to sell 241,580,000 of the shares in the Company,
         being 40.0% of the issued shares in the Company, and being the shares
         expressed to be subject to this Agreement in Schedule 1 (the "SHARES"),
         and the Purchaser is willing to purchase the Shares, in accordance with
         the provisions of this Agreement.

     D.  The Vendor intends to sell the remaining 362,370,000 shares in the
         Company by means of an initial public offering of the shares involving
         a combined global offering to members of the public and institutional
         and professional investors in New Zealand and to institutional and
         professional investors in Australia (the "AUSTRALASIAN OFFERING") and
         to institutional and professional investors in the United States and
         other countries (the "INTERNATIONAL OFFERING").

     E.  It is intended that the International Offering will be fully
         underwritten on a basis which is consistent with usual practice in
         international financial markets pursuant to a purchase agreement
         ("PURCHASE AGREEMENT"). The Purchase Agreement is intended to be
         conditional on settlement of the sale of the Shares pursuant to this
         Agreement. Settlement of the sale of the Shares pursuant to this
         Agreement is intended to occur contemporaneously with settlement under
         the Purchase Agreement.
<PAGE>
 
                                    -2-


     F.   The Purchaser and the Guarantor acknowledge that:

          (a) the Vendor has incurred, and will incur, significant costs in
              relation to the Contact IPO;

          (b) those costs have been incurred in reliance on the Shares being
              sold contemporaneously with the sale of the shares the subject of
              the Contact IPO; and

          (c) failure by the Purchaser and Guarantor to satisfy their
              obligations under this Agreement may result in settlement under
              the Contact IPO being delayed or cancelled resulting in loss to
              the Vendor.

     G.   The Guarantor is willing to guarantee the performance by the Purchaser
          of its obligations under this Agreement.


     IT IS AGREED:

     1.   INTERPRETATION

     1.1  Definitions: In this Agreement (including in the Recitals), unless the
          context otherwise requires:

          "ACCEPTABLE BANK" means an internationally recognised bank with a
          credit rating for long term debt of AA- or better, as issued by
          Standard & Poor's (or a comparable credit rating issued by another
          internationally recognised rating agency);

          "AGREEMENT" means this Agreement, together with the Schedules;

          "AUSTRALASIAN OFFERING" is defined in Recital D;

          "BASE RATE" means for any period:

          (a) the mid or "FRA" "settlement" rate for bank accepted bills of
              exchange having a tenor equivalent to the term of the relevant
              period as quoted on the Reuters page BKBM (or any successor page)
              at or about 10:45 a.m. on the date on which such rate is to be
              determined (expressed as a percentage); or

          (b) if such rate is not available then such rate reasonably determined
              by a bank, nominated for that purpose by the Governor of the
              Reserve Bank of New Zealand, to be the nearest practicable
              equivalent;

          "BID BOND" means the bid bond in the amount of $25 million issued by
          an Acceptable Bank in favour of the Vendor in connection with the
          Purchaser's bid, as required by section 3 of the Bidding Rules;
<PAGE>
 
                                    -3-


          "BIDDING RULES" means the bidding rules dated January 1999 issued by
          the Vendor relating to the sale of the Shares by international tender
          as the same may have been amended from time to time, the operative
          version of which as at the Final Bid Date is attached as Schedule 4;

          "BUSINESS" means the businesses carried on by the Group as at the
          Final Bid Date;

          "BUSINESS DAY" means a day (other than a Saturday or Sunday) on which
          registered banks (within the meaning of the Reserve Bank of New
          Zealand Act 1989) are open for the transaction of normal banking
          business in Wellington;

          "COMPANY" is defined in Recital A;

          "CONDITION DATE" means 29 October 1999;

          "CONFIDENTIAL INFORMATION" is defined in clause 9.3;

          "CONTACT IPO" means the intended initial public offering of up to
          362,370,000 shares in the Company to be effected by means of the
          Australasian Offering and the International Offering;

          "DEFAULT INTEREST" is defined in clause 5.5;

          "DOLLARS" and the sign "$" means New Zealand dollars;

          "ECNZ" means Electricity Corporation of New Zealand Limited;

          "ENCUMBRANCE" or "ENCUMBRANCE" includes a debenture, mortgage, charge
          (whether fixed or floating), pledge, lien, hypothecation, title
          retention, equity, deferred purchase, option and any other security
          interest or third party right whether legal or equitable (and
          references to "ENCUMBER" are to be construed accordingly);

          "EXECUTION DATE" means the date of execution of this Agreement by the
          Crown, being a date no later than 21 days after the Final Bid Date;

          "FINAL BID DATE" means the final date for delivery of final bids under
          the Bidding Rules, as set out in clause 3.5 of the Bidding Rules and
          as amended, if at all, by the Vendor in accordance with the Bidding
          Rules;

          "GOVERNMENT DOCUMENTS" means any New Zealand Government cabinet papers
          or ministerial papers;

          "GROUP" means the Company and the Subsidiaries;

          "INTERNATIONAL OFFERING" is defined in Recital D;

          "LETTER OF CREDIT" means the irrevocable standby letter or letters of
          credit, as required by section 3 of the Bidding Rules, in favour of
          the Vendor issued by an
<PAGE>
 
                                    -4-


          Acceptable Bank or Acceptable Banks for, in aggregate, the full amount
          of the Purchase Price and otherwise in the form set out in Schedule 2,
          or in such other form as agreed by the Vendor in writing;

          "OFFERING DOCUMENTS" means the documents that are, or are intended to
          be, made available to potential investors in the Company in relation
          to the Contact IPO, whether in New Zealand or elsewhere;

          "ORDERS IN COUNCIL" means the Order or Orders in Council which bring
          into force sections 3(1) and 3(7) of the State-Owned Enterprises
          (Contact Energy Limited) Amendment Act 1998;

          "PURCHASE AGREEMENT" is defined in Recital E;

          "PURCHASE PRICE" means the sum specified in Schedule 6;

          "RELATED BODY CORPORATE" bears the same meaning as in the Securities
          Amendment Act 1988;

          "SCHEDULE" means a schedule to this Agreement;

          "SETTLEMENT" means the performance by the parties of their respective
          obligations under clauses 5.2 and 5.4;

          "SETTLEMENT DATE" means the date by and upon which the condition in.
          clause 6.1 is satisfied or waived (which date is intended to be the
          same as the date of settlement and completion under the Purchase
          Agreement), or such later date as the Vendor and the Purchaser agree
          in writing;

          "SHARES" is defined in Recital C;

          "SHAREHOLDING MINISTERS" means the Minister of Finance and the
          Minister Responsible for Contact Energy Limited;

          "STANDSTILL DEED" means the deed titled "Standstill Deed" entered into
          by the Purchaser and the Guarantor and in favour of the Vendor, the
          Company, the New Zealand Stock Exchange and each member of the
          Syndicate;

          "SUBSIDIARIES" means Contact United Energy Limited, Javelin Limited,
          Hawkes Bay Power Limited, Contact Australia Pty Limited and their
          respective subsidiaries (if any);

          "SYNDICATE" means ABN AMRO Rothschild (the equity capital markets
          joint venture of the Rothschild and ABN AMRO groups of companies), NM
          Rothschild & Sons Limited, Rothschild Australia Securities Limited,
          ABN AMRO Bank NV, ABN AMRO Corporate Finance Australia Limited, and
          every Related Body Corporate of any such company, and every other
          person identified in any of the
<PAGE>
 
                                    -5-

         Offering Documents as a manager and/or co-lead manager of the
         International Offering and/or the Australasian Offering;

         "VERIFICATION CERTIFICATE" means the certificate as defined in the
         Bidding Rules; and

         "WARRANTY" means a warranty in terms of clause 7.

     1.2 PARTIES: In this Agreement, a reference to any party is to a party to
         this Agreement and includes, as far as is consistent with the
         provisions of this Agreement, that party's successors in title and
         permitted assigns.

     1.3 STATUTES: In this Agreement, any reference to a statute or statutory
         provision, or order or regulation made under it, includes:


         (a) that statute, provision, order or regulation, as amended, modified,
             re-enacted or replaced from time to time (whether before or after
             the Execution Date); and

         (b) any previous statute, statutory provision, order or regulation
             amended, modified, re-enacted or replaced by that statute,
             provision, order or regulation.

     1.4 GENERAL REFERENCES: In this Agreement, any reference to:

         (a) a "PERSON" includes an individual, body corporate, an association
             of persons (whether corporate or not), a trust, estate and agency
             of a state (in each case, whether or not having separate legal
             personality and whether incorporated or existing in New Zealand or
             elsewhere);

         (b) a "SUBSIDIARY" is to a subsidiary as defined in the Companies Act
             1993 or the Corporations Law (Australia);

         (c) one gender includes each other gender;

         (d) the singular includes the plural and vice versa;

         (e) an agreement includes that agreement as modified, supplemented,
             novated or substituted from time to time; and

         (f) time is to New Zealand standard time.

     1.5 HEADINGS: Headings and the table of contents are to be ignored in
         construing this Agreement.

     1.6 JOINT AND SEVERAL - PURCHASER: Where two or more persons are named as
         "the Purchaser" the expression "the Purchaser" shall be a reference to
         each of the said persons severally as well as any two or greater number
         of them jointly, and the
<PAGE>
 
                                    -6-


          obligations and agreements of the Purchaser in this Agreement shall
          bind each of them and every two or greater number of them jointly and
          each of them severally provided however that the delivery by or on
          behalf of the Vendor of any notice, document or information to any one
          or more of them shall be deemed to be delivery to all of them.


     1.7  JOINT AND SEVERAL - GUARANTOR: Where two or more persons are named as
          "the Guarantor" the expression "the Guarantor" shall be a reference to
          each of the said persons severally as well as any two or greater
          number of them jointly, and the obligations and agreements of the
          Guarantor in this Agreement shall bind each of them and every two or
          greater number of them jointly and each of them severally provided
          however that the delivery by or on behalf of the Vendor of any notice,
          document or information to any one or more of them shall be deemed to
          be delivery to all of them.


     2.   SALE OF THE SHARES

     2.1  AGREEMENT TO SELL: The Vendor will sell, as beneficial owner, and the
          Purchaser will purchase, the Shares on and with effect from the
          Settlement Date.

     2.2  CONDITION OF THE SHARES: The Shares will, on transfer to the
          Purchaser, be free from Encumbrances and have the benefit of all
          rights attaching to them including the right to receive all dividends
          declared or paid, or distributions (as that term is defined in the
          Companies Act 1993) made, on the Shares after the Settlement Date.

     3.   PURCHASE PRICE

     3.1  PURCHASE PRICE: The Purchaser shall pay the Purchase Price to the
          Vendor before 2:00 p.m. on the Settlement Date. Until the whole of the
          Purchase Price is finally received by the Vendor no right, title or
          interest in the Shares shall pass to the Purchaser.

     3.2  PAYMENTS: All payments to be made by a party under this Agreement will
          be made free of any deduction, withholding, set-off, counterclaim,
          restriction or condition.

     3.3  CORE ACQUISITION PRICE: The Purchase Price does not include any
          capitalised interest. In addition, the parties agree that the "lowest
          price" for the purposes of the definition of "core acquisition price"
          in section OB 1 of the Income Tax Act 1994 is equal to the Purchase
          Price.

     4.   PURCHASER'S OBLIGATIONS

     4.1  LETTER OF CREDIT: Within seven days following the Execution Date the
          Purchaser will establish, or will procure the establishment of, the
          Letter of Credit and deliver the same to the Vendor. Upon receipt of
          the Letter of Credit, the Vendor will return
<PAGE>
 
                                    -7-


          the Bid Bond to the Purchaser, (subject to compliance by the Purchaser
          with all obligations secured thereby), undrawn and uncalled, and shall
          advise the provider of the Bid Bond in writing that the Bid Bond is no
          longer required by it. The Letter of Credit may be drawn upon by the
          Vendor in or towards satisfaction of payment of the Purchase Price if
          the Vendor fails to pay the Purchase Price or any portion of it in
          accordance with clause 3.

     4.2  REMEDIES OF THE VENDOR ON DEFAULT: If the Purchaser fails to comply
          with clause 4.1 in any respect then, without prejudice to any other
          rights or remedies available to the Vendor at law or in equity,
          including making demand under the Bid Bond, the Vendor may cancel this
          Agreement by notice to the Purchaser and sue the Purchaser for
          damages. Where the Vendor is entitled to cancel this Agreement, the
          entry by the Vendor into a conditional or unconditional contract for
          the sale of the Shares by the Vendor will take effect as a
          cancellation of this Agreement by the Vendor if this Agreement has not
          previously been cancelled and such resale will be deemed to have
          occurred after cancellation. The damages claimable by the Vendor under
          this clause 4.2 will include the damages specified in clause 5.7.


     5.   SETTLEMENT AND PAYMENT OF THE PURCHASE PRICE

     5.1  TIME AND PLACE: Settlement will take place before 2:00 p.m. on the
          Settlement Date at the offices of Simpson Grierson at Unisys House,
          44-52 The Terrace, Wellington, New Zealand or at such other time or
          place as the Vendor and the Purchaser may agree.

     5.2  DOCUMENTS FOR DELIVERY BY VENDOR ON SETTLEMENT: On Settlement, and
          against compliance with clause 5.4, the Vendor will deliver to the
          Purchaser:

          (a) registrable transfers of the Shares, executed by the Shareholding
              Ministers, in favour of the Purchaser, together with the relevant
              share certificates (if any) or a certificate from an authorised
              officer of the Company certifying that no share certificates have
              been issued;

          (b) evidence that the Purchaser's name has been entered on the
              Company's share register as the holder of the Shares; and

          (c) a certified copy of each of the resolutions referred to in 
              clause 5.3.

     5.3  RESOLUTIONS: Prior to Settlement, the Vendor will procure the passing
          of the necessary resolutions of the shareholders or directors of the
          Company sanctioning the registration of the transfers of the Shares
          and appointing three Purchaser's nominees as directors to the board of
          the Company (notified to the Vendor just prior to Settlement) with
          effect from Settlement.
<PAGE>
 
                                      -8-


     5.4  REQUIREMENTS OF PURCHASER ON SETTLEMENT: On Settlement, the Purchaser
          will make or procure payment of the Purchase Price in accordance with
          clause 3.

     5.5  DEFAULT INTEREST:

          (a) If the Purchaser does not pay, or the Vendor does not receive,
              under the Letter of Credit or otherwise, any sum payable under or
              in terms of this Agreement as and when due the Purchaser will, on
              demand by the Vendor, pay interest on that unpaid sum ("DEFAULT
              INTEREST").

          (b) Default Interest will accrue without the necessity for demand or
              notice on any unpaid sum from day to day from the due date up to
              the date of actual payment, before and after judgment, in
              accordance with this clause. Default Interest shall be calculated
              and payable by reference to successive periods. Each such period
              shall be of one month or such shorter period as the Vendor may
              from time to time select and the rate of interest applicable to
              the unpaid amount for a particular period shall be the rate which
              is two per cent above the Base Rate determined on the first day of
              the relevant period or if such date is not a Business Day on the
              next following Business Day. Default Interest payable under this
              clause shall be due and payable at the end of each period by
              reference to which it is calculated, or at the time of payment of
              the relevant unpaid amount if prior to the end of such a period
              (at the applicable rate but calculated daily for such part-
              period), and if not paid shall be capitalised and itself bear
              interest accordingly.

     5.6  REMEDIES OF THE VENDOR ON DEFAULT: If the Vendor has complied, or is
          in a position to comply, with its obligations under clause 5.2 and
          clause 5.3 and the Purchaser does not pay, or the Vendor does not
          receive, under the Letter of Credit or otherwise, the Purchase Price
          or the Purchaser does not meet all of the Purchaser's other
          obligations to be performed on the Settlement Date then:

          (a) without prejudice to any other rights or remedies available to the
              Vendor at law or in equity, the Vendor may:

              (i)  sue the Purchaser for specific performance; or

              (ii) cancel this Agreement by notice to the Purchaser and sue the
                   Purchaser and/or Guarantor for damages (provided that any
                   such cancellation shall not affect clause 12 or clause 15.3,
                   each of which shall remain in effect subject to and in
                   accordance with its terms); and

          (b) where the Vendor is entitled to cancel this Agreement, the entry
              by the Vendor into a conditional or unconditional contract for the
              sale of the Shares by the Vendor will take effect as a
              cancellation of this Agreement by the Vendor if this Agreement has
              not previously been cancelled and such resale will be deemed to
              have occurred after cancellation.
<PAGE>
 
                                    -9-


5.7  DAMAGES CLAIMABLE BY THE VENDOR: The damages claimable by the Vendor
     under clause 5.6 (a)(ii) and clause 4.2 will include all damages
     claimable at common law or in equity and will also include (but will
     not be limited to):


     (a)  in the event that the Contact IPO is cancelled as a consequence of
          cancellation of this Agreement, all costs incurred by the Vendor in
          respect of or in relation to the Contact IPO and/or its cancellation
          including, without limitation, all fees and disbursements paid or
          payable by the Vendor to the Syndicate or any other advisers;


     (b)  in the event that the Contact IPO is delayed as a consequence of
          cancellation of this Agreement, all costs incurred by the Vendor in
          respect or in relation to the delay of the Contact IPO including,
          without limitation, the costs involved in preparing new or amended
          Offer Documents, and all fees and disbursements paid or payable by the
          Vendor to the Syndicate or any other advisers in respect of the same;
          and


     (c)  any loss incurred by the Vendor on any bona fide resale or attempted
          resale of the Shares or the shares the subject of the Contact IPO. The
          amount of that loss may include:

          (i)  in the case of cancellation under clause 5.6(a)(ii), interest on
               the Purchase Price at the Default Interest rate described in
               clause 5.5(b) from the Settlement Date to the settlement of such
               resale; and

          (ii) all costs and expenses reasonably incurred in any resale or
               attempted resale,


          together, in the case of cancellation under clause 5.6(a)(ii), with
          interest at the Default Interest rate described in clause 5.5(b) on
          any such loss from the date of settlement of the resale until payment
          of the loss (and the interest thereon).


5.8  THIRD PARTY CONSENTS: The Vendor will, in its capacity as the beneficial
     owner of the Company, use all reasonable endeavours to procure that the
     Company co-operates with the Purchaser to seek, prior to the Settlement
     Date, the consents of all parties who are parties to leases and other
     contracts with the Company under which consent is necessary as a
     consequence of a change in shareholding of the Company and which the
     Purchaser desires to obtain.

6.   CONDITIONS OF SETTLEMENT

6.1  CONDITION PRECEDENT: Settlement is conditional on the Purchase Agreement
     being executed and the obligations of the parties to the Purchase Agreement
     being unconditional, save in respect of any condition relating to
     settlement or completion under this Agreement.
<PAGE>
 
                                    -10-


6.2  WAIVER OF CONDITION: The condition in clause 6.1 has been inserted for the
     benefit of both the Vendor and the Purchaser and may be waived only by
     written agreement between them.

6.3  CONSEQUENCES OF NON-FULFILMENT: Should the condition in clause 6.1 not be
     satisfied or waived by 1.00 p.m. on the Condition Date, then this Agreement
     may be cancelled by written notice given by the Vendor to the Purchaser or
     the Purchaser to the Vendor.

6.4  NOTIFICATION BY VENDOR: The Vendor undertakes to notify the Purchaser of
     the date on which it is expected the condition in clause 6.1 will be
     satisfied (being the intended date of settlement and completion under the
     Purchase Agreement), and of any changes in that date, as soon as it is
     aware of the same. In any event, the Vendor will give no less than three
     Business Days' notice to the Purchaser of the date on which the condition
     in clause 6.1 is expected to be satisfied.

6.5  CONDITION SUBSEQUENT: If, after Settlement has been completed, settlement
     and completion under the Purchase Agreement does not occur on the
     Settlement Date for any reason, then Settlement shall be reversed, the
     transfers delivered by the Vendor under clause 5.2(a) shall be of no
     further force and effect, the Purchaser shall return to the Vendor all such
     transfers and any other documents delivered by the Vendor under clause 5.2
     and, against such return, the Vendor shall refund the Purchase Price paid
     by the Purchaser in accordance with clause 3, to the extent so paid. Upon a
     refund of the Purchase Price to the Purchaser under this clause 6.5 this
     Agreement shall be deemed cancelled.

6.6  EFFECT OF CANCELLATION: Upon cancellation of this Agreement under clause
     6.3 or clause 6.5 all parties will be released from all of their
     obligations under this Agreement provided that any such cancellation and
     release:

     (a)  shall not discharge or otherwise affect any liability which any party
          may have to any other party in respect of any breach of or failure to
          comply with this Agreement prior to the time of cancellation;

     (b)  shall be without prejudice to any claim which any party has against
          any other party in relation to any such liability; and

     (c)  shall not affect clause 12, or clause 15.3, each of which shall
          remain in effect subject to and in accordance with its terms.

7.   WARRANTIES


7.1  VENDOR'S WARRANTIES: The Vendor hereby represents and warrants in favour of
     the Purchaser (which Warranties will be deemed to be repeated on each day
     up to and including the Settlement Date) that:

     (a)  the Shares, together with the shares being offered by the Vendor
          pursuant to the Contact IPO and any shares included in any over-
          allotment option that
<PAGE>
 
                                    -11-


          may be granted to the Syndicate under the Purchase Agreement, comprise
          all of the issued shares in the Company;


     (b)  the Shares are fully paid;

     (c)  the Shares are beneficially owned by the Vendor and the Vendor has
          full power, right and authority to sell and procure the transfer of
          the Shares;

     (d)  there are no agreements or restrictions, whether arising out of
          legislation, regulations, agreement or otherwise, preventing or
          restricting or inhibiting the Vendor from carrying out or procuring
          such sale and transfer in the manner provided by this Agreement;

     (e)  on the transfer of the Shares to the Purchaser, property in the Shares
          will pass to the Purchaser free from any Encumbrances;

     (f)  the Vendor has full power and authority to enter into this Agreement
          and to carry out the transactions provided for in this Agreement, and
          this Agreement has been duly executed and delivered by the Vendor and
          is a valid and binding document of the Vendor;


     (g)  the Company has not declared or paid any dividend, or made any
          distribution (as that term is defined in the Companies Act 1993), and
          will not declare or pay any dividend or make any such distribution
          (as the case may be), during the period beginning on 30 September 1998
          and ending on (and including) the Settlement Date, other than as
          disclosed in writing to the Purchaser before the Final Bid Date; and

     (h)  neither the Vendor nor the Company is a party to, nor will it prior to
          Settlement enter into, any agreement or arrangement providing for a
          right, entitlement or option for any person to take shares or
          convertible securities in the Company, other than for the purposes of
          the Contact IPO or as disclosed in writing to the Purchaser before the
          Final Bid Date.


7.2  WARRANTIES OF THE PURCHASER AND GUARANTOR: Each of the Purchaser and the
     Guarantor hereby represents and warrants in favour of the Vendor (which
     Warranties will be deemed to be repeated on each day up to and including
     the Settlement Date) that:

     (a)  it has full power and authority to enter into this Agreement and the
          Standstill Deed and to carry out the transactions provided for in this
          Agreement and the Standstill Deed;

     (b)  the execution, delivery and performance of this Agreement and the
          Standstill Deed and the consummation of the transactions provided for
          in this Agreement and the Standstill Deed by it has been duly
          authorised by all requisite corporate action and no director of the
          Purchaser or the Guarantor is
<PAGE>
 
                                    -12-


          interested in any transaction evidenced by this Agreement other than
          as a director of the Purchaser or the Guarantor (as the case may be);

     (c)  this Agreement and the Standstill Deed have been duly executed and
          delivered by it and are valid and binding upon it;

     (d)  it has obtained all requisite or necessary clearances, authorisations
          or consents from such regulatory authorities as may be necessary,
          whether in New Zealand or overseas, for the implementation of this
          Agreement and the Standstill Deed including, but not limited to,
          clearances or authorisations under the Commerce Act 1986 and consents
          under the Oversees Investment Regulations 1995, which clearances,
          authorisations or consents are valid on the Execution Date and will
          remain valid up to the Settlement Date;

     (e)  it has obtained all requisite or necessary approvals under or waivers
          from the requirements of the Listing Rules of the New Zealand Stock
          Exchange or any similar rules of a recognised stock exchange for the
          implementation of this Agreement and the Standstill Deed; and

     (f)  there was, and is, no error, misstatement or omission in respect of
          the written information and confirmations provided by or on behalf of
          the Purchaser to the Vendor and the Company in the Verification
          Certificate in connection with the Contact IPO, as contemplated by
          section 4 of the Bidding Rules.

7.3  ACKNOWLEDGEMENT: Each of the Purchaser and the Guarantor acknowledges and
     agrees that, except for the Warranties of the Vendor specified in clause
     7.1:

     (a)  it has entered into this Agreement in reliance solely on its own
          judgment and not in reliance on any representations of the Vendor, the
          Company, the Subsidiaries, the Company's associated companies or their
          respective advisers, directors, employees, officers or agents;

     (b)  it has made its own independent enquiry and investigations into the
          affairs of the Company, the Subsidiaries and all of the Company's
          associated companies (including, without limitation, the business,
          operations, financial condition, prospects, creditworthiness and
          status of them) and though various information or statements of fact
          or opinion may have been supplied or made to the Purchaser by the
          Vendor, the Company, the Subsidiaries, the Company's associated
          companies or their respective advisers, directors, employees, officers
          or agents, the Purchaser unconditionally waives, and agrees not to
          facilitate, assist or encourage the taking or making of, any claim
          against the Vendor, the Company, the Subsidiaries, the Company's
          associated companies or their respective advisers, directors,
          employees, officers or agents (whether arising in tort, in contract,
          by operation of law or otherwise) in respect of any such matters;

     (c)  all express or implied or other representations or warranties of the
          Vendor, the Company, the Subsidiaries or their respective advisers,
          directors,
<PAGE>
 
                                    -13-


          employees, officers or agents in relation to the sale of the Shares
          are hereby expressly excluded;

     (d)  neither the Vendor, the Company, the Subsidiaries, the Company's
          associated companies nor their respective advisers, directors,
          employees, officers or agents have made or make any representation or
          have given or give any warranty (express or implied) as to the
          accuracy, content, completeness, value or otherwise of, nor have or
          accept any liability (whether arising in tort, in contract, by
          operation of law or otherwise) in respect of, any information or
          statements of fact or opinion (written, oral or otherwise) directly or
          indirectly provided or available to or used by the Purchaser in
          connection with the transactions evidenced by this Agreement and the
          Purchaser unconditionally waives, and agrees not to facilitate, assist
          or encourage the taking or making of, any claim against any of them in
          respect of any such matters;

     (e)  neither the Vendor, the Company, the Subsidiaries, the Company's
          associated companies nor their respective advisers, directors,
          employees, officers or agents has given, or will give, any
          representation or warranty as to the future prospects of the Group
          including, for the avoidance of doubt, the Business; and

     (f)  the references in this paragraph and in the previous paragraphs of
          this clause to "advisers" include references to ABN AMRO Rothschild
          (the equity capital markets joint venture of the Rothschild and ABN
          AMRO groups of companies), NM Rothschild & Sons Limited, Rothschild
          Australia Securities Limited, NM Rothschild & Sons (Singapore)
          Limited, ABN AMRO Bank NV, ABN AMRO Corporate Finance Australia
          Limited, ABN AMRO Equities NZ Limited, ABN AMRO New Zealand Limited
          and every Related Body Corporate of any such company and their
          respective directors, officers, employees and agents and that the
          acknowledgements and agreements given in the foregoing paragraphs of
          this clause 7.3 are promises which confer, and are intended to confer,
          a benefit upon the Vendor, the Company, the Subsidiaries, the
          Company's associated companies and their respective advisers,
          directors, employees, officers and agents and are intended to be
          enforceable against the Purchaser and the Guarantor at the suit of
          each such person pursuant to the Contracts (Privity) Act 1982.

7.4  ENTIRE AGREEMENT: This Agreement together with the Bid Bond, the Letter of
     Credit, the deed of indemnity (in the form set out in Schedule 3), the
     Standstill Deed and the confidentiality deed entered into by the party
     named in Schedule 6 and dated as specified in Schedule 6 in favour of the
     Vendor and other named beneficiaries:

     (a)  constitutes the entire understanding and agreement of the parties
          relating to the sale and purchase of the Shares; and
<PAGE>
 
                                    -14-


     (b)  supersedes and extinguishes all other agreements and understandings
          between the parties relating to that sale and purchase prior to the
          date of this Agreement.


8.   PENDING SETTLEMENT


8.1  CONDUCT OF BUSINESS: Pending Settlement, and notwithstanding that the
     Vendor executes this Agreement on the Execution Date, the Vendor will use,
     or undertakes that it has used, in its capacity as beneficial owner of the
     Shares, all reasonable endeavours to procure that, from the Final Bid Date:

     (a)  each member of the Group will:

          (i)   subject to paragraph (b) of this clause 8.1, operate and
                conduct the Business in the normal course of business in
                accordance with the business practices employed by the Group as
                at the Final Bid Date;

          (ii)  properly keep and maintain all necessary books of account
                (reflecting in a true and fair manner, in accordance with the
                accounting policies of the Group as at the Final Bid Date, all
                transactions effected by the Group or to which it has been a
                party, in so far as they relate to the Business), minute books,
                records, the share register and other statutory registers and
                books;


          (iii) maintain its assets in as good a state of operating condition
                and repair as they are on the Final Bid Date, except for
                ordinary depreciation and fair wear and tear;


          (iv)  maintain in full force and effect all existing insurances in
                respect of the Business and the assets of the Business;


          (v)   promptly notify the Purchaser (other than in respect of normal
                debt collection) of any law suits, claims, proceedings,
                investigations or adverse events which may occur, be threatened,
                brought, asserted or commenced against it, its officers or
                directors, involving in any way the Business or the assets of
                the Business; and

          (vi)  use its best efforts to preserve intact its good name and
                reputation, and its existing relationships with suppliers of
                goods and services, employees, governmental authorities and
                customers; and

     (b)  each member of the Group will not, without the prior written consent
          of the Purchaser (such consent not to be unreasonably withheld):

          (i)  make any alterations to its existing constitution or name, or
               take any steps towards altering its capital structure, other than
               as disclosed in writing to the Purchaser before the Final Bid
               Date;
<PAGE>
 
                                    - 15 -


          (ii)  declare or pay, or approve the declaration or payment of, any
                dividend or otherwise make any distribution (as that term is
                defined in the Companies Act 1993), other than as disclosed in
                writing to the Purchaser before the Final Bid Date;


          (iii) alter, or agree to alter, the remuneration or any of the
                conditions of employment of its directors, officers or employees
                in force as at the Final Bid Date provided however that changes
                of remuneration or conditions may be made consistent with the
                business practices employed by it as at the Final Bid Date;

          (iv)  make, or enter into a legal commitment in respect of, or draw
                down or use any borrowing or other facilities for, any item of
                capital expenditure not consistent with the capital expenditure
                projections attached as Schedule 5;

          (v)   give any guarantee of or indemnity in respect of the liabilities
                of any other person other than to any party to the Purchase
                Agreement or in the ordinary course of business;

          (vi)  create or allow any Encumbrance to arise over the Business or
                assets of the Business (other than any title retention arising
                in the ordinary course of business or any Encumbrance arising by
                operation of law); or


          (vii) dispose of any of the assets or undertakings of the Business,
                other than disposals in the ordinary course of business, for a
                cash consideration payable in full at the time of disposal equal
                to or greater than book value, or disposals of redundant or
                other non-material assets;

     and in any case of action taken or omitted to be taken in accordance with
     either clauses 8.1(a) or 8.1(b), that action is taken or not taken (as the
     case may be) having regard to, and in such a manner so as not to be
     inconsistent with the contents of the Offering Documents in the forms of
     the drafts of such documents as at the Final Bid Date, subject to any
     amendments required to be made in order to ensure the Offering Documents
     meet the requirements of all relevant laws.

8.2  EVENTS PENDING SETTLEMENT: If any event, matter or thing (other than a
     breach of the Vendor's Warranties, or other agreement of the Vendor to be
     performed by it under this Agreement, in either case as a result solely of
     the Vendor's actions) occurs pending Settlement that affects the value of
     the Shares, or if anything comes to the Purchaser's attention that may
     influence the decision of it or a purchaser to complete the purchase of the
     Shares and whether material or not, and whether or not amounting to force
     majeure, the Purchaser will not be able to re-negotiate the Purchase Price
     nor claim any deduction, set-off or counterclaim in respect thereof nor
     refuse to settle.
<PAGE>
 
                                    -16-


8.3  ORDERS IN COUNCIL: The Vendor will use all reasonable endeavours to
     promulgate the Orders in Council as soon as is reasonably practicable after
     the Settlement Date.


9.   RESTRICTIONS


     This clause 9 shall have no force or effect prior to Settlement, but shall
     come into full force and effect as from Settlement.


9.1  DISCLOSURE OF INFORMATION: As further consideration for the Purchaser
     agreeing to purchase the Shares, the Vendor hereby undertakes with the
     Purchaser that it will not, except with the written consent of the
     Purchaser, or as required by law, at any time after Settlement itself make
     use of or disclose to any person any information of a secret or
     confidential nature supplied to it by the Company and relating to the
     Business.


9.2  GOVERNMENT DOCUMENTS:

     (a)  The Purchaser hereby undertakes with the Vendor that if any Government
          Documents are in or come into the possession of any member of the
          Group, any company associated to the Company or the Purchaser, the
          Purchaser will (or will procure that the relevant member of the Group,
          or, to the extent that it is able, any company associated to the
          Company, will) promptly deliver them to the State Services Commission
          or any other person nominated for this purpose by the Vendor.

     (b)  The Vendor will, at the request of the Purchaser, formulate and agree
          procedures with the Purchaser and/or any one or more members of the
          Group for its reasonable access to any Government Documents the
          Purchaser or the relevant member or members of the Group need or needs
          for the purposes of any legal action or proceedings or the carrying on
          of the Business or its other activities.


9.3  CONFIDENTIAL INFORMATION;

     (a)  All confidential information (including Government Documents) in the
          possession of a member of the Group or any company associated to the
          Company relating to the business or activities carried on or out prior
          to the Settlement Date by any government department or ministry
          ("CONFIDENTIAL INFORMATION") but excluding such confidential
          information (other than Government Documents) which is the property of
          a member of the Group, will be kept confidential by the Purchaser, the
          Group and its employees, and, to the extent the Purchaser can procure
          the same (using best endeavours), any company associated to the
          Company, unless:

          (i)  the Purchaser, any member of the Group, any company associated to
               the Company or any employee is required by law or the listing
<PAGE>
 
                                    -17-


               requirements of a recognised stock exchange to disclose that
               Confidential Information; or

          (ii) the Vendor agrees in writing that that Confidential Information
               may be disclosed.

     (b)  Furthermore, upon any termination of this Agreement, or upon demand by
          the Vendor or its advisers, the Purchaser will:

          (i)  either return to such person as they may direct or destroy, at
               the option of the Vendor or its advisers (as the case may be),
               all of the Confidential Information (including copies thereof) in
               the possession or control of the Purchaser or its directors,
               officers, employees, related companies or its legal, accounting,
               taxation or financial advisers; and

          (ii) destroy all copies of any analyses, compilations, studies or
               other documents prepared by the Purchaser or for the Purchaser's
               use containing or reflecting any Confidential Information
               excluding, in the case of advisers to the Purchaser:

               (A)  particular documents and materials held on solicitors' files
                    and which continue to be held on such files; and

               (B)  those documents and materials that may reasonably be
                    required for internal audit purposes or as a justification
                    for any advice that may have been provided by any such
                    adviser to the Purchaser regarding the acquisition of the
                    Shares under this Agreement.


     (c)  Upon the return or destruction (as the case may be), as specified in
          paragraph (b), of all such Confidential Information, the Purchaser
          will provide to the Vendor a certificate from an authorised officer of
          the Purchaser stating that the Purchaser has complied with its
          obligations under this clause.


9.4  DISCLOSURE: If the Purchaser, any member of the Group, any company
     associated to the Company, that associated company or any employee is
     required by law to disclose any Confidential Information the Purchaser
     will, subject to its legal obligations:

     (a)  consult with the Vendor prior to the Purchaser, that member of the
          Group, that associated company or that employee making such
          disclosure; and


     (b)  procure (or, in the case of such an associated company, use best
          endeavours to procure) that all reasonable requirements of the Vendor
          in relation to the disclosure of that Confidential Information are
          followed strictly.


9.5  CLAUSE 9 TO SURVIVE TERMINATION: The obligations of the Purchaser under
     this clause 9 will survive termination of this Agreement.
<PAGE>
 
                                    -18-


10.   PURCHASER'S COVENANTS


10.1  INDEMNITY: The Purchaser will indemnify and keep indemnified the Vendor in
      respect of, and to the extent of, any costs, losses, damages, claims,
      liabilities and expenses incurred or suffered by the Vendor, or which may
      be made against it, as a result of or attributable to:

      (a)  any matter or thing at any time being found to be other than as
           warranted or agreed by the Purchaser under any provision of this
           Agreement; or

      (b)  any failure by the Purchaser to perform its obligations under this
           Agreement.


10.2  NO ACTION AGAINST OFFICERS: The Purchaser and the Guarantor, at all times
      after Settlement, agree not to take, institute or make, or facilitate,
      assist or encourage the taking, instituting or making of, and will, to the
      extent they can do so, procure, and will otherwise use all reasonable
      endeavours to procure that, no member of the Group or the Company's
      associated companies takes, institutes or makes any action, proceeding,
      claim or demand against:

      (a)  any present or former director or officer of the Company or the
           Subsidiaries or the Company's associated companies (in such person's
           capacity as a director or officer of the Company or the Subsidiaries,
           or the Company's associated companies, or purporting to act as such,
           or in any other capacity acting or purporting to act on behalf of the
           Company or the Subsidiaries, or the Company's associated companies,
           or arising out of such person's association with, or wish to assist,
           the Company or the Subsidiaries or the Company's associated
           companies) in respect of any act, omission, matter or thing arising
           or occurring on or prior to the Settlement Date except in so far as
           such act, omission, matter or thing is the result of a lack of good
           faith by such director or officer; or

      (b)  any present or former shareholder of (or beneficial owner of shares
           in the capital of) the Company or the Subsidiaries or the Company's
           associated companies (in such person's capacity as shareholder) in
           respect of any act, omission, matter or thing arising or occurring
           prior to the Settlement Date except in so far as such act, omission,
           matter or thing may give rise to a claim against the Vendor under an
           express provision of this Agreement.


      The undertaking contained in this clause is given for the benefit of each
      present or former director, officer or shareholder of (or beneficial owner
      of shares in the capital of) the Company and the Subsidiaries and the
      Company's associated companies and is intended to be enforceable against
      the Purchaser at the suit of each such person pursuant to the Contracts
      (Privity) Act 1982.
<PAGE>
 
                                    -19-

     10.3 INDEMNITY FOR ERRORS ETC. IN INFORMATION FOR CONTACT IPO: On the
          Execution Date the Purchaser and the Guarantor will enter into the
          indemnity in the form set out in Schedule 3. The undertaking contained
          in this clause is given for the benefit of each of the Vendor, the
          Company, its directors and former directors and each member of the
          Syndicate and is intended to be enforceable against the Purchaser at
          the suit of each such person pursuant to the Contracts (Privity) Act
          1982.

     11.  NO GREATER RIGHTS

          Notwithstanding any other provision of this Agreement, the Purchaser:

          (a) acknowledges that the Company and the Subsidiaries and the
              Company's associated companies have no better title to any asset
              transferred, or purportedly transferred, by ECNZ to the Company
              pursuant to the sale and purchase agreement dated 13 November 1995
              between ECNZ and the Company than that title which ECNZ had in
              respect of that asset as at the date of settlement of such
              agreement; and


          (b) agrees to waive, release and discharge forever, and to use
              reasonable endeavours to procure that, as soon as is practicable
              after Settlement, the Company and each Subsidiary and each company
              associated to the Company will waive, release and discharge
              forever, all past, present and future actions, claims, rights,
              suits, demands and proceedings of every kind whatever available to
              it against ECNZ in respect of any such asset that has not been
              validly transferred to the Company under that sale and purchase
              agreement as a result of ECNZ not having had good title to that
              asset as at the date of settlement of such agreement, each of
              those waivers to be in a form satisfactory to the Vendor.


     12.  GUARANTEE AND INDEMNITY


     12.1 GUARANTEE: The Guarantor unconditionally and irrevocably guarantees to
          the Vendor:

          (a) the due and punctual payment by the Purchaser of all moneys which:

              (i) from time to time become due from the Purchaser to the Vendor
                  under this Agreement; or

             (ii) arise out of or are payable in relation to any breach by the
                  Purchaser of or failure by the Purchaser to comply with any of
                  its obligations under this Agreement; and

          (b) the due, punctual and proper performance and observance by the
              Purchaser of all of its other obligations under this Agreement.
<PAGE>
 
                                    - 20 -

     12.2  NO DISCHARGE: The liability of the Guarantor under this guarantee
           will constitute a principal obligation of the Guarantor and will not
           be discharged, released or otherwise affected:


           (a) by any delay, grant of time, release or compromise granted by the
               Vendor to the Purchaser or any other person;

           (b) by cancellation or termination of this Agreement;


           (c) by the Vendor exercising or refraining from exercising any rights
               against the Purchaser or any other person; or

           (d) by any other act, omission, matter, circumstance or law whereby
               the Guarantor would, but for the provisions of this clause, have
               been released from liability under this Agreement.

     12.3  CONTINUING GUARANTEE: This guarantee will remain in full force and
           effect until all liabilities and obligations of the Purchaser under
           this Agreement (including, without limitation, any liability of a
           type referred to in clause 6.6) have been fully discharged and all
           moneys payable to the Vendor under this Agreement have been fully
           paid, including moneys the payment or satisfaction of which is
           subsequently avoided or affected in any way, whether under any
           statutory provision or otherwise, so as to deprive the Vendor of the
           full benefit of such payment or satisfaction.

     12.4  INDEMNITY: As a separate and independent obligation, the Guarantor
           will be liable, and agrees to indemnify the Vendor, for all costs,
           losses, damages, claims, liabilities and expenses incurred or
           suffered by the Vendor, or that may be made against it, as a result
           of:

           (a) the failure on the part of the Purchaser to pay all moneys that
               from time to time become due from the Purchaser to the Vendor
               under this Agreement; or

           (b) any breach of any other obligation of the Purchaser under this
               Agreement.


     12.5  PAYMENT: The Guarantor will pay to the Vendor on demand all amounts
           payable pursuant to the guarantee and the indemnity contained in this
           clause 12.

     12.6  ABILITY TO ENFORCE: The Vendor may enforce the guarantee and the
           indemnity contained in this clause 12 against the Guarantor without
           first taking any steps or proceedings against the Purchaser.
<PAGE>
 
                                    -21-


     13.  EXPENSES


          Whether or not any of the transactions contemplated by this Agreement
          are consummated, each of the parties will (unless otherwise specified
          in this Agreement) bear its own legal and accountancy costs and other
          expenses of and incidental to the preparation, negotiation, execution
          of this Agreement and Settlement.


     14.  DELAY IN EXERCISE OF RIGHTS


     14.1 NO DELAY: No delay, grant of time, release, compromise, forbearance
          (whether partial or otherwise) or other indulgence by one party in
          respect of any breach of any other party's obligations under this
          Agreement is to:

          (a) operate as a waiver of or prevent the subsequent enforcement of
              that obligation; or

          (b) be deemed a delay, grant of time, release, compromise, forbearance
              (whether partial or otherwise) or other indulgence in respect of,
              or a waiver of, any subsequent or other breach.

     14.2 EXERCISE OF RIGHTS AND WAIVERS:

          (a) Time is of the essence in this Agreement but no failure to
              exercise, and no delay in exercising, a right by a party will
              operate as a waiver of that right, nor will a single or partial
              exercise of a right preclude another or further exercise of that
              right or the exercise of another right.

          (b) No waiver by a party of its rights under this Agreement will be
              effective unless it is in writing signed by that party.

     14.3 PARTIAL INVALIDITY: The illegality, invalidity or unenforceability of
          a provision of this Agreement under any law will not affect the
          legality, validity or enforceability of that provision under another
          law or the legality, validity or enforceability of another provision.

     15.  FURTHER ASSURANCES AND POST SETTLEMENT

     15.1 FURTHER ASSURANCES: The parties will sign, execute and do all deeds,
          schedules, acts, documents and things as may reasonably be required by
          any other party, effectively to carry out and give effect to the terms
          and intentions of this Agreement, whether before or after Settlement.
          Without limiting the generality of the foregoing the Purchaser and the
          Guarantor will not take any steps that might adversely affect the
          success of the Contact IPO.
<PAGE>
 
                                    - 22 -


     15.2 POST SETTLEMENT: Notwithstanding Settlement, and to the extent that
          any provision of this Agreement is not performed or fulfilled at
          Settlement, that provision will not merge on Settlement and will
          continue in full force and effect.

     15.3 PUBLIC ANNOUNCEMENTS: The Purchaser agrees that it will not make any
          public statement or announcement with respect to this Agreement or any
          matter which is provided for in this Agreement or the Contact IPO,
          including without limitation the signing of this Agreement and
          Settlement nor will it enter into any discussion or correspondence, or
          otherwise have any communications of any nature, with any financial
          institution, analyst, broker or any other person in respect of the
          Contact IP0 (other than its financial adviser engaged prior to the
          date of this Agreement to assist it solely in respect of its
          acquisition of the shares), except in the case of a public
          announcement or statement where and to the extent that any such public
          statement or announcement is required by law, the listing requirements
          of a recognised stock exchange or the constitution (or its equivalent)
          of the Purchaser or the (Guarantor and then only in strict accordance
          with the Securities Act 1978, the Securities Regulations 1983 and the
          securities laws of any other relevant jurisdiction, having regard to
          the Contact IPO, and not without the Purchaser:

          (a) having provided the Vendor with a reasonable opportunity to
              comment on the proposed public statement or announcement prior to
              the making of the same; and

          (b) having considered, and having not declined (other than on
              reasonable grounds) to take account of, any comments which the
              Vendor may make.

     16.  AMENDMENTS

          No amendment to this Agreement will be effective unless it is in
          writing and signed by all the parties.

     17.  ASSIGNMENT

     17.1 SUCCESSORS: This Agreement will be binding on and enure for the
          benefit of the parties and their respective successors and, in the
          case of the Purchaser, its permitted assignees or transferees.

     17.2 ASSIGNMENT:

          (a) The Purchaser may not assign or transfer all or any part of its
              rights or obligations under this Agreement without the prior
              written consent of the Vendor, which may be given or withheld by
              the Vendor at its absolute discretion and, if given, given on such
              terms as it thinks fit.
              
<PAGE>
 
                                    -23-


          (b) Each permitted assignee or transferee of the Purchaser will have
              the same rights against the Vendor under this Agreement as if
              named in this Agreement as Purchaser.

     18.  NOTICES

     18.1 FORM OF NOTICE: Any notice or other communication to be made or
          delivered to any party under this Agreement is to be:

          (a) in writing;

          (b) signed by a person authorised by the sender; and

          (c) sent by facsimile, personal delivery or post to the facsimile
              number or address, and marked for the attention of the person or
              office holder (if any), from time to time designated by that party
              to the other parties for the purposes of this Agreement.

          The initial facsimile number, address and relevant person or office
          holder of the Vendor is set out under its name at the end of this
          Agreement, and for the Purchaser and the Guarantor is set out in
          Schedule 6.

     18.2 NOTICE EFFECTIVE: No communication is to be effective until received.
          A communication will, however, be deemed to be received by the
          addressee:


          (a) in the case of a facsimile, on the Business Day on which it is
              despatched or, if despatched after 5:00 p.m. (in the place of
              receipt) on a Business Day or, if despatched on a non-Business
              Day, on the next Business Day after the date of dispatch, in each
              case evidenced by the receipt of a transmission report from the
              machine on which the facsimile was transmitted;

          (b) in the case of personal delivery, when delivered;


          (c) in the case of a letter, if posted to an overseas address, on the
              third Business Day after posting by airmail, and if posted to a
              postal address in New Zealand, on the first Business Day after
              posting by fastpost; and

          (d) in the case of a communication to the Purchaser or Guarantor
              where the Purchaser or Guarantor comprises two or more persons,
              by receipt or deemed receipt by any one or more of such persons.

      19. COUNTERPARTS

          (a) This Agreement may be executed in two or more counterparts
              (including facsimile copies) each of which will be deemed an
              original, but all of which together will constitute one and the
              same instrument.
<PAGE>
 
                                     - 24 -

          (b) A party may enter into this Agreement by executing any
              counterpart.

     20.  GOVERNING LAW

     20.1 NEW ZEALAND LAW: This Agreement is to be governed by and construed in
          accordance with the laws of New Zealand.

     20.2 SUBMISSION TO JURISDICTION: Each of the parties irrevocably and
          unconditionally agrees that the Courts of New Zealand have non-
          exclusive jurisdiction to hear and determine every matter that may
          arise out of or in connection with this Agreement.

     20.3 WAIVER OF IMMUNITY: The Vendor acknowledges that its obligations under
          this Agreement are private and commercial acts and, to the maximum
          extent permissible by law, irrevocably waives any rights to claim
          sovereign or other immunity from suit or action or process in respect
          of its obligations under this Agreement.

     21. PROCESS AGENT

          (a) The Purchaser and the Guarantor severally appoint the person
              specified in Schedule 6 (registered office of which at the
              Execution Date is set out in Schedule 6) in New Zealand to
              receive, for it and on its behalf, service of process of any legal
              action or proceedings in New Zealand arising out of or in
              connection with this Agreement and warrants that such person has
              agreed to so act (and that appointment will only be revocable if,
              contemporaneously with that revocation, the Purchaser or the
              Guarantor (as the case may be) appoints a substitute process agent
              in New Zealand acceptable to the Vendor and warrants that such
              person has agreed to so act).

          (b) Such service will be deemed completed on delivery to that process
              agent (whether or not it is forwarded to and received by the
              Purchaser or the Guarantor (as the case may be)).

      EXECUTED as an agreement.
<PAGE>
 
                                    -25-


     SIGNED on behalf of                        )
     HER MAJESTY THE QUEEN                      ) /s/ BILL ENGLISH
     IN RIGHT OF NEW ZEALAND                    ) ----------------
     acting through her Minister of             )
     Finance BILL ENGLISH                       )
     in the presence of:                        )



      /s/  ILLEGIBLE SIGNATURE       Signature of Witness
     ----------------------------- 
           Solicitor                 Occupation
     -----------------------------
           Wellington                Address
     -----------------------------

     Address: Commercial and Financial Branch, The Treasury, 1 the Terrace,
              Wellington

     Facsimile No.:499 0437

     Attention: Branch Manager

     SIGNED on behalf of                        )
     HER MAJESTY THE QUEEN                      ) /s/ A. L. SMITH 
     IN RIGHT OF NEW ZEALAND                    ) ---------------
     acting through her Minister                ) 
     Responsible for Contact Energy             )
     Limited A. LOCKWOOD SMITH                  )
     in the presence of:                        )

      /s/   ILLEGIBLE SIGNATURE      Signature of Witness
     -----------------------------
      /s/  Solicitor                 Occupation
     -----------------------------

      /s/  Wellington                Address
     -----------------------------

     Address: Commercial and Financial Branch, The Treasury, 1 the Terrace,
              Wellington

     Facsimile No.:499 0437

     Attention: Branch Manager
<PAGE>
 
                                    - 26 -


     SIGNED as a deed by    )         /s/  GERRY LOUGHMAN
     EDISON MISSION ENERGY  )        --------------------------------
     TAUPO LIMITED in the   )        Authorised Signatory
     presence of:           )
                            )         /s/  MICHAEL KELLAND
                            )        ---------------------------------  
                            )        Authorised Signatory

Witness:

 /s/  THOMAS ROBERT FAIL
---------------------------
Signature of witness                 of

 /s/  Thomas Robert Fail
---------------------------
Full name of witness

      Solicitor
---------------------------
Occupation of witness

      Wellington
---------------------------
Address of witness


     SIGNED as a deed by        )     /s/  GERRY LOUGHMAN
     EDISON MISSION ENERGY      )    ---------------------------------
     in the presence of:        )    Authorised Signatory
                                )
                                )     /s/  MICHAEL KELLAND
                                )    ---------------------------------
                                )    Authorised Signatory

Witness:

 /s/  THOMAS ROBERT FAIL
---------------------------
Signature of witness

      Thomas Robert Fail
---------------------------
Full name of witness

      Solicitor
---------------------------
Occupation of witness

      Wellington
---------------------------
Address of witness
<PAGE>
 
<TABLE> 
<CAPTION> 
                                   SCHEDULE 1

                               REGISTERED HOLDERS
-----------------------------------------------------------------------------------------
<S>                             <C>                           <C> 
     Name and Address           Holding of Shares             Shares Subject to This
                                                                     Agreement
-----------------------------------------------------------------------------------------
Minister of Finance             301,975,000 ordinary shares   120,790,000 ordinary shares
Parliament Buildings
Wellington
-----------------------------------------------------------------------------------------
Minister Responsible for        301,975,000 ordinary shares   120,790,000 ordinary shares
Contact Energy Limited
Parliament Buildings
Wellington                                                         
-----------------------------------------------------------------------------------------
</TABLE> 
<PAGE>
 
                                  SCHEDULE 2

                           FORM OF LETTER OF CREDIT


                              [Issuer Letterhead]


                             IRREVOCABLE STANDBY 
                           LETTER OF CREDIT NO. [ ]
                              DATED: [          ]


     To: [Crown]
          [address]


     [Acceptable Bank] (the "Issuer") hereby issues this irrevocable standby
     Letter of Credit No. [ ] in favour of [Crown] (the "Beneficiary") at the
     request of [Purchaser/Other party] (the "Account Party") [on behalf of
     [Purchaser] (the "Purchaser").

     This Letter of Credit is issued in connection with the [Account
     Party's/Purchaser's] obligations to pay certain amounts pursuant to an
     Agreement for the Sale and Purchase of Shares in Contact Energy Limited
     dated [       ] 1999 between the Beneficiary and the [Account
     Party/Purchaser] [and other/s] (the "Agreement") for the sum of [Purchase
     Price (or part thereof, if more than one letter of credit)] New Zealand
     Dollars (NZ$[Purchase Price (or part thereof, if more than one letter of
     credit)]) (the "Maximum Amount") and shall expire on the date of receipt by
     the Beneficiary of the Maximum Amount in accordance with this Letter of
     Credit or 7 November 1999 whichever is the earlier (the "Expiry Date").

     This Letter of Credit is available for payment up to, in aggregate, the
     Maximum Amount immediately on presentation at [New Zealand Address] no
     later than 3pm on a business day on or before the Expiry Date of a
     communication purporting to be from the Beneficiary to the Issuer quoting
     "Drawing under [Issuer] Standby Letter of Credit No. [ ] dated 
     [           ]" and containing the following statement: "We certify on
     behalf of the
<PAGE>
 
                                    -2-


      Beneficiary that the [Account Party/Purchaser] has failed to pay NZ$[    ]
      being [the whole/part] of the Purchase Price under the Agreement. We
      therefore make demand on you under the above referenced letter of credit
      in the amount of NZ$[        ]. Please pay this amount to [nominated
      account details]. Terms used in this communication have the same meaning
      as in the above referenced Letter of Credit."


      Partial drawings are permitted.


      The Issuer undertakes to the Beneficiary that demands made in compliance
      with the terms of this Letter of Credit will be duly honoured on
      presentation without reference to the Account Party and agrees to pay the
      funds demanded telegraphically, with same day value to the Beneficiary's
      nominated account referred to in the demand without any discount,
      deduction, set-off or counterclaim whatsoever.

      Except as otherwise stated herein this Letter of Credit is subject to the
      Uniform Customs and Practice for Documentary Credits 1993 Revision
      International Chamber of Commerce Publication No. 500 and, subject to
      that, is governed by, and is to be construed in accordance with the
      provisions of, the laws of New Zealand. The Issuer irrevocably submits to
      the nonexclusive jurisdiction of the courts of New Zealand in respect of
      any matter arising in relation to this Letter of Credit.


      SIGNED by 
      [Issuer]
      by:


      in the presence of:


      ------------------------

      ------------------------

      ------------------------
<PAGE>
 
                                   SCHEDULE 3

                               FORM OF INDEMNITY


--------------------------------------------------------------------------------

                               DEED OF INDEMNITY


THIS DEED dated the                     day of                              1999


BETWEEN    HER MAJESTY THE QUEEN IN RIGHT OF NEW ZEALAND acting by and through
           her MINISTER OF FINANCE and her MINISTER RESPONSIBLE FOR CONTACT
           ENERGY LIMITED (the "CROWN")


AND        EDISON MISSION ENERGY TAUPO LIMITED (the "PURCHASER")


AND        EDISON MISSION ENERGY (the "GUARANTOR")


RECITALS:

A.   The Purchaser has, contemporaneously with this deed, entered into an
     agreement for sale and purchase (the "AGREEMENT FOR SALE AND PURCHASE")
     with the Crown pursuant to which it will acquire from the Crown 241,580,000
     of the shares in Contact Energy Limited (the "COMPANY"), being 40.0% of the
     issued shares in the Company.

B.   The Crown intends to sell the remaining 362,370,000 shares in the Company
     by means of an initial public offering of the shares involving a combined
     global offering to members of the public and institutional and professional
     investors in New Zealand and to institutional and professional investors in
     Australia (the "AUSTRALASIAN OFFERING"), and to institutional and
     professional investors in the United States and other countries (the
     "INTERNATIONAL OFFERING").

C.   The Purchaser has provided certain written information to the Crown and the
     Company for inclusion in offering documents relating to the Contact IPO.

D.   Such information includes information relating to the Purchaser's
     operations and differences in strategic vision in relation to the Company
     from that outlined in the offering documents.
<PAGE>
 
                                     -2-


E.   In terms of the Agreement for Sale and Purchase, the Purchaser has agreed
     to indemnify the Crown, the Company, its directors and former directors and
     each member of the Syndicate against, amongst other things, any loss or
     liability arising as a result of, or attributable to, any error, or
     misstatement or omission in respect of such information.

F.   The parties wish to record the terms of the indemnity as set out below.


WITNESSES AS FOLLOWS: 

1.   INTERPRETATION

     1.1    DEFINITIONS: In this deed (including in the Recitals), unless the
            context otherwise requires:

            "AGREEMENT FOR SALE AND PURCHASE" is defined in Recital A;

            "AUSTRALASIAN OFFERING" is defined in Recital D of the Agreement for
            Sale and Purchase;

            "BIDDING RULES" means the bidding rules dated January 1999 issued by
            the Crown relating to the sale of shares in the Company by
            international tender, as the same may have been amended from time
            to time, the operative version of which as at the Final Bid Date is
            attached as the schedule to this deed;

            "BUSINESS DAY" means a day (other than a Saturday or Sunday) on
            which registered banks (within the meaning of the Reserve Bank of
            New Zealand Act 1989) are open for the transaction of normal banking
            business in Wellington;

            "COMPANY" is defined in Recital A;

            "CONTACT IPO" means the intended initial public offering of up to
            362,370,000 shares in the Company to be effected by means of the
            Australasian Offering and the International Offering;

            "FINAL BID DATE" means the final date for delivery of final bids
            under the Bidding Rules, as set out in clause 3.5 of the Bidding
            Rules and as amended, if at all, by the Crown in accordance with the
            Bidding Rules;

            "INDEMNIFIED PARTIES" means the Crown, the Company, the directors
            and former directors of the Company and every member of the
            Syndicate;
<PAGE>
 
                                     -3-


            "INFORMATION" means any and all written information and
            confirmations in the Verification Certificate;

            "INTERNATIONAL OFFERING" is defined in Recital D of the Agreement
            for Sale and Purchase;

            "LIABILITIES" includes, but is not limited to, all claims, losses,
            costs (including legal costs), damages, charges and expenses which
            the Indemnified Parties, or any of them, may suffer or incur in
            respect of any action or claim, including all proceedings, suits,
            enquiries or investigations, which may be brought or threatened to
            be brought against the Indemnified Parties, or any of them, and
            whether or not such proceedings are successful, compromised or
            settled and however the liabilities are suffered or properly and
            reasonably incurred in disputing any such proceedings;

            "OFFERING DOCUMENTS" means the documents that are, or are intended
            to be, made available to potential investors in the Company in
            relation to the Contact IPO, whether in New Zealand or elsewhere;

            "RELATED BODY CORPORATE" bears the same meaning as in the Securities
            Amendment Act 1988;

            "SYNDICATE" means ABN AMRO Rothschild (the equity capital markets
            joint venture of the Rothschild and ABN AMRO groups of companies),
            NM Rothschild & Sons Limited, Rothschild Australia Securities
            Limited, ABN AMRO Bank NV, ABN AMRO Corporate Finance Australia
            Limited, and every Related Body Corporate of any such company, and
            every other person identified in any of the Offering Documents as a
            manager and/or co-lead manager of the International Offering and/or
            the Australasian Offering;

            "VERIFICATION CERTIFICATE" means the certificate referred to in
            section 4 of the Bidding Rules;


     1.2    PARTIES: In this deed, a reference to any party is to a party to
            this deed and includes, as far as is consistent with the provisions
            of this deed, that party's successors in title and permitted
            assigns.

     1.3    STATUTES: In this deed, any reference to a statute or statutory
            provision, or order or regulation made under it, includes:

            (a)   that statute, provision, order or regulation, as amended,
                  modified, re-enacted or replaced from time to time; and
<PAGE>
 
                                      -4-


            (b)   any previous statute, statutory provision, order or regulation
                  amended, modified, re-enacted or replaced by that statute,
                  provision, order or regulation.


     1.4    GENERAL REFERENCES: In this deed, any reference to:

            (a)   a "PERSON" includes an individual, body corporate, an
                  association of persons (whether corporate or not), a trust,
                  estate and agency of a state (in each case, whether or not
                  having separate legal personality and whether incorporated or
                  existing in New Zealand or elsewhere);

            (b)   a "SUBSIDIARY" is to a subsidiary as defined in the Companies
                  Act 1993 or the Corporations Law (Australia);

            (c)   one gender includes each other gender;

            (d)   the singular includes the plural and vice versa;

            (e)   an agreement includes that agreement as modified,
                  supplemented, novated or substituted from time to time; and

            (f)   time is to New Zealand standard time.


     1.5    HEADINGS: Headings are to be ignored in construing this deed.


     1.6    JOINT AND SEVERAL - PURCHASER: Where two or more persons are named
            as "the Purchaser" the expression "the Purchaser" shall be a
            reference to each of the said persons severally as well as any two
            or greater number of them jointly, and the obligations and
            agreements of the Purchaser in this deed shall bind each of them and
            every two or greater number of them jointly and each of them
            severally provided however that the delivery by or on behalf of the
            Crown of any notice, document or information to any one or more of
            them shall be deemed to be delivery to all of them.


     1.7    JOINT AND SEVERAL - GUARANTOR: Where two or more persons are named
            as "the Guarantor" the expression "the Guarantor" shall be a
            reference to each of the said persons severally as well as any two
            or greater number of them jointly, and the obligations and
            agreements of the Guarantor in this deed shall bind each of them and
            every two or greater number of them jointly and each of them
            severally provided however that the delivery by or on behalf of the
            Crown of any notice, document or information to any one or more of
            them shall be deemed to be delivery to all of them.
<PAGE>
 
                                      -5-
 
 
     1.8    JOINT AND SEVERAL - GENERAL: The obligations and agreements of the
            Purchaser and the Guarantor in this deed shall bind each of them and
            every two or greater number of them jointly and each of them
            severally.

 
2.   WARRANTY AS TO INFORMATION

     The Purchaser and the Guarantor represent and warrant to the Indemnified
     Parties that:

     2.1    STATEMENTS OF FACT: all statements of fact contained in the
            Information are true and accurate in all material respects and not
            misleading in any material respect;

 
     2.2    STATEMENTS OF OPINION: all statements of opinion and all statements
            of intention and expectation in the Information are honestly held by
            it after careful consideration and such expressions of opinion and
            statements of intention and expectation are fair and reasonable; and
 
 
     2.3    NO OMISSIONS: the Information does not omit any particular which is
            material in the context of the Contact IP0.


3.   INDEMNITY
 
 
     3.1    INDEMNIFICATION BY PURCHASER AND GUARANTOR: The Purchaser and the
            Guarantor hereby indemnifies and saves harmless each of the
            Indemnified Parties from and against any and all Liabilities, and
            any other claims, losses, costs (including legal costs), damages,
            charges and expenses which the Indemnified Parties, or any of them,
            may suffer or incur, in each case arising out of or attributable to
            any breach of the representations and warranties set out in clause 2
            where the Information in respect of which the breach arises is
            included in or referred to, in any way, (provided such is not
            materially different to the form in which it was provided) in all or
            any of the Offering Documents or relied upon by any of the
            Indemnified Parties in the compilation of all or any of the Offering
            Documents.

 
     3.2    LIABILITIES: Without limiting the generality of clause 3.1, the
            indemnity contained in that clause shall extend to, and for the
            purposes of this deed be read to include any liabilities arising:

 
            (a)   by virtue of the terms of, or by the reference to, any
                  document by which the Contact IP0 is made;
 
 
            (b)   by virtue of the communication, disclosure or use of any of
                  the Information (materially in the form in which it was
<PAGE>
 
                                  -6-


                  provided) which has been disclosed by or on behalf of the
                  Purchaser for the purposes of the formulation, preparation and
                  implementation of the Contact IPO or all or any of the
                  Offering Documents;


            (c)   whether or not the liabilities arise in tort, contract, by
                  statute, by operation of law or otherwise howsoever; and


            (d)   wherever and whenever the liabilities are suffered, incurred
                  or brought.


     3.3    DEFENCE OF CLAIMS: If any legal proceeding shall be instituted, or
            any claim or demand made, against any Indemnified Party in respect
            of which the Purchaser and/or Guarantor may be liable hereunder,
            such Indemnified Party shall give prompt written notice thereof to
            the Purchaser and Guarantor, and if they accept liability hereunder,
            the Purchaser and/or Guarantor shall have the right to defend any
            such litigation, action, suit, demand or claim for which such
            Indemnified Party may seek indemnification, provided that:


            (a)   the Purchaser and/or Guarantor obtains an opinion from counsel
                  nominated by the Crown that they have a better than even
                  prospect of success;


            (b)   the reputation of the Indemnified Parties is not unduly
                  harmed; and


            (c)   the insurers of the Indemnified Party do not object to the
                  defence of the litigation, action, suit, demand or claim by
                  the Purchaser and/or Guarantor;


            unless the legal proceeding instituted, or the claim or demand made,
            relates solely and exclusively to the Information, in which case the
            Purchaser and the Guarantor shall have an unconditional right to
            defend any such litigation, action, suit, demand or claim but only
            insofar as the relevant legal proceedings, claim or demand continues
            at all times thereafter to be related solely and exclusively to the
            Information. The Crown shall extend reasonable co-operation in
            connection with and such defence, which shall be at the expense of
            the Purchaser and Guarantor.


     3.4    DEFENCE BY CROWN: If the Purchaser or Guarantor shall not have the
            right to assume the defence of any litigation, action, suit, demand
            or claim in accordance with clause 3.3, the Indemnified Parties
            shall have the absolute right to control the defence of and to
            settle, in their sole discretion and without the consent of the
            Purchaser or Guarantor, such litigation, action, suit, demand or
            claim.
<PAGE>
 
                                      -7-

 
4.   CONTRACTS (PRIVITY) ACT
 
     The warranties, covenants and agreements given by the Purchaser and the
     Guarantor in this deed are given for the benefit of each of the Indemnified
     Parties and are intended to be enforceable at the suit of each of them
     pursuant to the Contracts (Privity) Act 1982.

 
5.   ASSIGNMENT
 
     Neither the Purchaser nor the Guarantor may assign or transfer all or any
     part of its rights or obligations under this deed without the prior written
     consent of the Crown, which such consent may be given or withheld by the
     Crown at in absolute discretion and, if given, given on such terms and
     conditions as it thinks fit.

 
6.   DELAY AND EXERCISE OF RIGHTS
 
     6.1   NO DELAY: No delay, grant of time, release, compromise, forbearance
           (whether partial or otherwise) or other indulgence by one party in
           respect of any breach of any other party's obligations under this
           deed is to:

           (a)   operate as a waiver of or prevent the subsequent enforcement of
                 that obligation; or

 
           (b)   be deemed a delay, grant of time, release, compromise,
                 forbearance (whether partial or otherwise) or other indulgence
                 in respect of, or a waiver of, any subsequent or other breach.

 
     6.2   EXERCISE OF RIGHTS AND WAIVERS: Time is of the essence in this deed
           but no failure to exercise, and no delay in exercising, a right by a
           party will operate as a waiver of that right, nor will a single or
           partial exercise of a right preclude another or further exercise of
           that right or the exercise of another right. No waiver by a party of
           its rights under this deed will be effective unless it is in writing
           signed by that party.

 
7.   FURTHER ASSURANCES
 
     The parties will sign, execute and do all deeds, schedules, acts, documents
     and things as may reasonably be required by any other party, effectively to
     carry out and give effect to the terms and intentions of this deed.
<PAGE>
 
                                      -8-

 
8.   NOTICES
 
     8.1   FORM OF NOTICE: Any notice or other communication to be made or
           delivered to any party under this deed is to be:

           (a)   in writing;
 
           (b)   signed by a person authorised by the sender; and

           (c)   sent by facsimile, personal delivery or post to the facsimile
                 number or address, and marked for the attention of the person
                 or office holder (if any), from time to time designated by that
                 party to the other parties for the purposes of this deed.
 
           The initial facsimile number, address and relevant person or office
           holder of each party is set out under its name at the end of the
           Agreement for Sale and Purchase.

     8.2   NOTICE EFFECTIVE: No communication is to be effective until received.
           A communication will, however, be deemed to be received by the
           addressee:

           (a)   in the case of a facsimile, on the Business Day on which it is
                 despatched or, if despatched after 5:00 p.m. (in the place of
                 receipt) on a Business Day or, if despatched on a non-Business
                 Day, on the next Business Day after the date of dispatch, in
                 each case evidenced by the receipt of a transmission report
                 from the machine on which the facsimile was transmitted;

           (b)   in the case of personal delivery, when delivered;
 
           (c)   in the case of a letter, if posted to an overseas address, on
                 the third Business Day after posting by airmail, and if posted
                 to a postal address in New Zealand, on the first Business Day
                 after posting by fastpost; and

           (d)   in the case of a communication to the Purchaser or Guarantor
                 where the Purchaser or Guarantor comprises two or more persons,
                 by receipt or deemed receipt by any one or more of such
                 persons.

 
9.   COUNTERPARTS
 
     This deed may be executed in two or more counterparts (including facsimile
     copies) each of which will be deemed an original, but all of which together
<PAGE>
 
                                      -9-


     will constitute one and the same instrument. A party may enter into this
     deed by executing any counterpart.

 
10.  GOVERNING LAW

     10.1   NEW ZEALAND LAW: This deed is to be governed by and construed in
            accordance with the laws of New Zealand.

     10.2   SUBMISSION TO JURISDICTION: Each of the parties irrevocably and
            unconditionally agrees that the Courts of New Zealand have non-
            exclusive jurisdiction to hear and determine every matter that may
            arise out of or in connection with this deed.

     10.3   WAIVER OF IMMUNITY: The Crown, to the maximum extent permissible by
            law, irrevocably waives any rights to claim sovereign or other
            immunity from suit or action or process in respect of this Deed
            and/or its subject matter.
<PAGE>
 
                                  - 10 -


     In witness of which this deed has been executed.

     SIGNED on behalf of                     )
     HER MAJESTY THE QUEEN                   )
     IN RIGHT OF NEW ZEALAND                 )
     acting through her Minister of          )
     Finance BILL ENGLISH                    )
     in the presence of:                     )


     _______________________________         Signature of Witness

     _______________________________         Occupation

     _______________________________         Address


     Address:        Commercial and Financial Branch, The Treasury, 1 the 
                     Terrace, Wellington

     Facsimile No.:  499 0437

     Attention:      Branch Manager

     SIGNED on behalf of                     )
     HER MAJESTY THE QUEEN                   )
     IN RIGHT OF NEW ZEALAND                 )
     acting through her Minister for         )
     Responsible For Contact Energy          )
     Limited A. LOCKWOOD SMITH               )
     in the presence of:                     )


     _______________________________         Signature of Witness

     _______________________________         Occupation

     _______________________________         Address          


     Address:        Commercial and Financial Branch, The Treasury, 1 the
                     Terrace, Wellington

     Facsimile No.:  499 0437

     Attention:      Branch Manager
<PAGE>
 
                                     -11-


     SIGNED as a deed by                     )
     EDISON MISSION ENERGY                   )  ______________________________
     TAUPO LIMITED in the                    )  Authorised Signatory
     presence of:                            )
                                             )
                                             )  ______________________________
                                             )  Authorised Signatory


     Witness:

     ____________________________________
     Signature of witness

     ____________________________________
     Full name of witness

     ____________________________________
     Occupation of witness

     ____________________________________
     Address of witness


     SIGNED as a deed by                     )
     EDISON MISSION ENERGY                   )  ______________________________
     in the presence of:                     )  Authorised Signatory
                                             )
                                             )
                                             )  ______________________________
                                             )  Authorised Signatory


     Witness:

     ____________________________________
     Signature of witness

     ____________________________________
     Full name of witness

     ____________________________________
     Occupation of witness

     ____________________________________
     Address of witness


                                   SCHEDULE

                                 BIDDING RULES

                               [To be attached.]
<PAGE>
 
                                  SCHEDULE 4

                                 BIDDING RULES

--------------------------------------------------------------------------------

                                 BIDDING RULES

                          FOR THE SALE OF 40 PER CENT

                                OF THE SHARES IN

                             CONTACT ENERGY LIMITED

                                   ISSUED BY


                           HER MAJESTY THE QUEEN IN
                             RIGHT OF NEW ZEALAND


                                   ADVISED BY


                              ABN AMRO ROTHSCHILD



                                                January 1999

--------------------------------------------------------------------------------
<PAGE>
 
    TABLE OF CONTENTS


    1. Offer for Sale and summary of Bidding Rules.......................... 1
    2. Indicative Bids...................................................... 3
    3. Final Bid Process.................................................... 5
    4. Initial Public Offering.............................................. 8
    5. General.............................................................. 9


    ENCLOSURES


    I.     Indicative Timetable
    II.    Letter of Application
    III.   Form of Bid Bond


    These Bidding Rules have been distributed and should be read in conjunction
    with an Information Memorandum in relation to Contact Energy Limited
    compiled by ABN AMRO Rothschild and dated January 1999 and the covering
    letter sent by ABN AMRO Rothschild dated 15 January 1999. Particular
    attention with respect to the sale process is drawn to paragraphs 1.5 and 15
    in the Information Memorandum as these Bidding Rules are not intended to be
    definitive as to every aspect of the sale process.
<PAGE>

--------------------------------------------------------------------------------
    DEFINITIONS


    "ABN AMRO ROTHSCHILD" means the Equity Capital Markets joint venture of the
    Rothschild and ABN AMRO Groups, which has been appointed to advise the Crown
    on the sale of its shareholding in Contact.

    "AWARDEE" means the successful Bidder.

    "BID" means the unilateral and irrevocable offer of the Bidder to acquire
    the Shareholding made pursuant to and in accordance with these Bidding
    Rules.

    "BID BOND" means the bond required to be submitted by each Bidder in
    accordance with and as further described in section 3.6.

    "BIDDER" means the persons referred to in section 1.3 and any parties named
    as purchaser or guarantor under the Sale and Purchase Agreement in that
    document as submitted on the Final Bid Date in accordance with section
    3.6(a).

    "BIDDING GROUP" means a group of investors that jointly participates in the
    Final Bid Process as a single Bidder.

    "BIDDING RULES" means these rules as approved by the Crown, as these may be
    amended, supplemented or clarified in accordance with section 5.1.

    "CONTACT" means Contact Energy Limited, a state enterprise within the
    meaning ascribed to that term by the State-Owned Enterprises Act 1986.

    "CD-ROMS" means the CD-Roms containing information relevant to Contact that
    will be provided to Bidders who are invited to participate in the Final Bid
    Process.

    "CROWN" means Her Majesty the Queen in right of New Zealand acting through
    and by her Minister of Finance and her Minister for State-Owned Enterprises.

    "DATA ROOM" means the data room or rooms each containing documents and other
    information relevant to Contact which will be open to Bidders who are
    invited to participate in the Final Bid Process.

    "FINAL BID PROCESS" means the process involving the submission of final Bids
    by the small number of Bidders and as outlined in Section 3.

    "GOVERNING LAWS" means the laws of New Zealand.

    "INFORMATION MEMORANDUM" means the information memorandum issued by the
    Crown in relation to the sale of the Shareholding dated January 1999.

    "IPO" means initial public offering within the meaning generally ascribed to
    that term by the financial services industry.
--------------------------------------------------------------------------------
<PAGE>
 
                                     - ii -

--------------------------------------------------------------------------------
    "OFFERING DOCUMENTS" means the prospectus, investment statement and Rule
    144A documentation pursuant to which shares in Contact are to be offered for
    sale by the Crown in an IPO.

    "SALE AND PURCHASE AGREEMENT" means the agreement to be executed by the
    Crown and the Awardee setting forth the terms upon which the Awardee shall
    acquire the Shareholding.

    "SECTION" refers to a section of these Bidding Rules.

    "SHAREHOLDING" in relation to Contact, means the 40 per cent of the ordinary
    shares of Contact being offered for sale by the Crown pursuant to the
    process outlined in these Bidding Rules.

    "STANDSTILL AGREEMENT" means the agreement between the Awardee and the Crown
    whereby for a specified period the Awardee will agree:

    (i)   not to sell or dispose of the Shareholding; and

    (ii)  not to acquire an interest in any other securities of Contact.

    "VERIFICATION CERTIFICATE" means the certificate in the form attached as
    Attachment IV.

    References to "party" or "interested party" are references to persons who
    may become Bidders whether alone or as a member of a Bidding Group.
--------------------------------------------------------------------------------
<PAGE>
 
    BIDDING RULES

    l.  OFFER FOR SALE AND SUMMARY OF BIDDING RULES

        1.1  The Crown is offering to sell the Shareholding by international
             tender. This sale will be made in conjunction with an IPO of
             Contact by which the Crown proposes to dispose of the balance of
             its shareholding in Contact. Following the IPO, it is intended that
             the ordinary shares of Contact offered for sale in the IPO will be
             listed on the New Zealand Stock Exchange, and possibly also on the
             Australian Stock Exchange.

        1.2  The sale process for the Shareholding will be governed by these
             Bidding Rules, as may be amended as outlined in section 5, and by
             the Governing Laws. Parties should note that amendments and any
             changes to the process will be notified through the website
             established by ABN AMRO Rothschild. The website should be regularly
             checked as interested parties will be deemed to have notice of any
             amendments or changes placed on the website.


        1.3  The sale process for the Shareholding will be a two-stage process:

             (i)  interested parties who have received a copy of the Information
                  Memorandum must submit indicative non-binding bids and meet
                  the other requirements set out in Section 2;

             (ii) the Crown will then select from those parties who have
                  submitted indicative non-binding bids and met the other
                  requirements set out in section 2, a small number of parties
                  who will be invited to undertake due diligence and participate
                  in the Final Bid Process (each such party, inter alia,
                  constituting a "Bidder"), as outlined in section 3.

        1.4  An indicative timetable outlining the key milestone dates (which as
             noted may be subject to change) is annexed as Attachment l.
             Interested parties and Bidders must adhere strictly to the
             timetable.

        1.5  By submitting indicative non-binding bids parties will be agreeing
             to be bound by these Bidding Rules.

        1.6  Parties should note that:

             (i)   aside from entering into the Sale and Purchase Agreement, the
                   Awardee will be expected to enter into the Standstill
                   Agreement (signed by all members of a Bidding Group where
                   relevant);

             (ii)  the sale of the Shareholding will be conditional upon the IPO
                   of Contact being successfully concluded; and
<PAGE>
 
                                   -2-


             (iii)   Bidders will be expected to provide certain information to
                     the Crown as part of the Contact IPO process and, if
                     successful, will be expected to indemnify the Crown,
                     Contact and its directors in relation to errors, omissions
                     and mis-statements relating to that information.
<PAGE>
 
                                   -3-


2.   INDICATIVE BIDS


     2.1  Interested parties wishing to participate in the Final Bid Process
          should submit an indicative non-binding bid (in the form annexed as
          Attachment II), together with the other information outlined in
          section 2.3.

     2.2  The indicative price should be a specified price rather than being
          expressed as a range of prices.

     2.3  The Crown wishes interested parties to provide documentary evidence of
          the following matters:

          (i)    existing ownership or significant operational experience in the
                 energy sector (parties intending to bid as a Bidding Group
                 should ensure that at least one member can meet this
                 requirement);

          (ii)   how their Bid will contribute to the success of the Contact IPO
                 (parties should include a brief indicative outline of their
                 broad intentions relating to Contact and indicate any
                 significant differences in strategic vision to that outlined by
                 Contact in the Information Memorandum);

          (iii)  their capacity to complete the process in the time required,
                 including financial capacity to fund the likely cost of the
                 Shareholding (details of financial accounts and any credit
                 ratings should be provided where appropriate);

          (iv)   clearance or authorisation granted under the Commerce Act 1986
                 or an explanation satisfactory to the Crown as to why
                 application for such is not necessary or evidence that they
                 have submitted an application for Commerce Commission clearance
                 that was registered by the Commerce Commission on or before 3
                 February 1999 (note: where a party or parties may directly or
                 indirectly have any local operations in the New Zealand energy
                 sector, the Crown will expect such party to seek and obtain
                 clearance or authorisation);

          (v)    that application for consent from the Overseas Investment
                 Commission has been made;

          (vi)   that any other regulatory consents required in New Zealand or
                 elsewhere have been obtained; and

          (vii)  evidence that a relevant senior employee representative of the
                 Bidder has the requisite corporate authority to investigate and
                 negotiate a purchase of the Shareholding.
<PAGE>
 
                                    -4-


     2.4  Indicative non-binding bids, together with the other information
          required as per section 2.3, should be delivered in a sealed envelope
          to the offices of ABN AMRO Rothschild at Level 11, Castrol House, 36
          Customhouse Quay, Wellington no later than 5:00pm on 3 February 1999,
          New Zealand time. Any late indicative bids will not be accepted.
<PAGE>
 
                                      -5-

3.   FINAL BID PROCESS


     3.1   A small number of interested parties who have complied with section 2
           will be invited to participate in the Final Bid Process, provided
           that in respect of any interested party who had applied for, and the
           Commerce Commission had registered, on or before 3 February 1999, an
           application for Commerce Commission clearance, if the Commerce
           Commission does not grant them clearance by 12 February 1999, their
           involvement in the Final Bid Process, including, without limiting the
           generality of the foregoing, the due diligence review referred to in
           section 2, shall cease forthwith.

     3.2   Bidders will be permitted to undertake a due diligence review of
           Contact in accordance with the procedures outlined by ABN AMRO
           Rothschild on behalf of the Crown.

     3.3   Bidders will be given the opportunity to comment on drafts of the
           Sale and Purchase Agreement and Standstill Agreement prior to the
           deadline for submission of final Bids. Drafts will be provided on 5
           February 1999. These documents will be able to be accessed through
           the website established by ABN AMRO Rothschild. Bidders' comments
           must be provided to the Crown, through ABN AMRO Rothschild, no later
           than 22 February 1999. The Crown, in its sole discretion, may accept
           or reject any comments. Final versions of these documents will be
           provided to Bidders on 5 March 1999. No further changes to these
           documents will be accepted.

     3.4   Reference to Bidders' involvement in relation to the IPO process is
           outlined in section 4.

     3.4A  All Bidders will be required to submit the identity and details of
           the proposed purchaser entity to ABN AMRO Rothschild no later than 22
           February 1999. Purchaser entities which are not the shortlisted
           Bidder notified by ABN AMRO Rothschild will be required to provide an
           acceptable Guarantor of their obligations under the Sale and Purchase
           Agreement. Parties intending to bid as a Bidding Group should note
           that they will be required to advise ABN AMRO Rothschild of the
           proposed consortium no later than 22 February 1999, and to submit to
           ABN AMRO Rothschild on that date the following information:

           (i)   details and the identity of the consortium members and all
                 relevant arrangements among them;

           (ii)  details and the identity of the proposed purchaser entity.

           The shortlisted Bidder, directly or through a wholly owned subsidiary
           will be required to own at least an effective 75% equity interest in
           the relevant
<PAGE>
 
                                      -6-


           Bidding Group and will be required to guarantee the obligations of
           the Bidding Group.

     3.5   Each final Bid for a Shareholding must be expressed to be an
           irrevocable and unconditional offer (executed as a deed) capable of
           acceptance within 21 days and must be delivered, in a sealed
           envelope, together with the documents referred to in section 3.6, to
           the offices of ABN AMRO Rothschild at Level 11, Castrol House, 36
           Customhouse Quay, Wellington by 5:00pm on 20 March 1999, New Zealand
           time. Any late Bids will not be accepted.

     3.6   The following documents or information must accompany final Bids:

           (i)   the Sale and Purchase Agreement (including the purchase price
                 for the Shareholding) and Standstill Agreement duly executed by
                 the Bidder (signed by all members of the Bidding Group, where
                 relevant);

           (ii)  a Bid Bond in the amount of NZ$25 million (in the form annexed
                 as Attachment III) from an internationally recognised bank with
                 a credit rating for long term debt of AA- or better, as issued
                 by Standard & Poors (or a comparable credit rating issued by
                 another internationally recognised rating agency);

           (iii) the Verification Certificate, duly executed by a senior
                 representative of the Bidder, for and on behalf of the Bidder;

           (iv)  evidence of due execution of all documents and of all
                 corporate, regulatory, governmental and other consents; and

           (v)   where the Bidder is a Bidding Group, executed copies of all
                 agreements, arrangements and understandings between the
                 members.

     3.7   The Sale and Purchase Agreement will be expressed to be conditional
           upon successful completion of the Contact IPO, such condition to be
           satisfied no later than 29 October 1999.

     3.8   The Bid Bond must secure a Bidder's obligations under these Bidding
           Rules, the Bid of the Bidder and the Sale and Purchase Agreement. The
           Bid Bond will be returned to the Bidder (undrawn and uncalled): (a)
           where the Bidder is the Awardee, in accordance with clause 4.1 of the
           Sale and Purchase Agreement; or (b) where the Bidder is not the
           Awardee, upon the Crown receiving a letter or letters of credit in
           accordance with clause 4.1 of the Sale and Purchase Agreement entered
           into with the Awardee.

     3.9   The successful Bidder, on being so notified by the Crown, shall be
           required to lodge, or procure the lodgement of, within 7 days
           thereafter, an
<PAGE>
 
                                      -7-

           irrevocable letter or letters of credit, in favour of the Crown,
           issued by an internationally recognised bank or banks having a credit
           rating for long term debt of AA- or better, as issued by Standard &
           Poors (or a comparable credit rating issued by another
           internationally recognised rating agency), for (in aggregate) the
           full purchase price of the Shareholding as recorded in the Sale and
           Purchase Agreement between the Crown and the Bidder.

     3.10  The Crown has sole and complete discretion to accept or reject any or
           all Bids of any or all Bidders, to cancel the sale process and to run
           the process generally as it deems fit.

     3.11  The Crown reserves the right to consider any factor when determining
           the successful Bid and to deal with any Bidder individually or
           simultaneously with others, or to revert back to other Bidders.

     3.12  The Crown shall have no obligation to accept any Bid whether or not
           such Bid represents the best and/or highest offer for the
           Shareholding.

     3.13  Without limiting the generality of sections 3.10 to 3.13, once
           parties have been short-listed to participate in the Final Bid
           Process, the Crown's decision as to the successful Bid is likely to
           be determined primarily on price.
<PAGE>
 
                                      -8-

4.   INITIAL PUBLIC OFFERING

     4.1   Submission of a Bid by a Bidder will constitute acknowledgement that
           the Crown proposes to sell the balance of the issued share capital in
           Contact (being 60% of the capital of Contact) through an IPO to be
           conducted in conjunction with the sale of the Shareholding. The IPO
           will:

           (a)   be managed and organised by ABN AMRO Rothschild;

           (b)   will consist of a public offer in New Zealand and a private
                 institutional offer in the United States of America and
                 elsewhere;

           (c)   will result in the shares in Contact being listed on both the
                 New Zealand Stock Exchange and possibly the Australian Stock
                 Exchange.

     4.2   Copies of the Offering Documents will be made available to Bidders on
           or about 18 February 1999. Bidders will not be expected to make
           extensive comments on the Offering Documents but will be expected to
           provide the information outlined in section 4.4 for inclusion,
           assuming they are successful, and indicate any differences in
           strategic vision in relation to Contact from that outlined in the
           Offering Documents.

     4.3   The Crown will appoint three nominees of the Awardee to the Board of
           Contact immediately prior to settlement of the Sale and Purchase
           Agreement (which is to occur on completion of the IPO just prior to
           stock exchange listing). The Crown does not wish to know the identity
           of the nominees until just prior to settlement.

     4.4   Each Bidder will be asked to provide a profile and information
           relating to its operations and other relevant information for
           inclusion in the Offering Documents, (assuming it is the successful
           Bidder). Such information shall be provided by Bidders to the Crown
           by 13 February 1999. Further comments in relation to any differences
           in strategic vision and any other comments are to be provided by
           Bidders no later than 23 February 1999. Bidders will also need to
           supply a Verification Certificate confirming their provision of, and
           agreement to use of, and confirmation of, the information and
           extracts specified in that certificate, which information and
           extracts are to be included in the Offering Documents substantially
           in the form in which it appears in the Verification Certificate.

     4.5   Bidders should note that the Sale and Purchase Agreement will contain
           covenants whereby the Awardee will provide an indemnity in favour of
           the Crown, Contact and its directors for errors, omissions and
           misstatements in relation to the information provided and
           confirmations made pursuant to section 4.4 and referred to in the
           Verification Certificate.
<PAGE>
 
                                      -9-

5.   GENERAL

     5.1   The Crown reserves the right at any time, in its sole discretion, to
           revoke, modify, amend or terminate any of these Bidding Rules or the
           indicative timetable without prior notification or justification. Any
           such changes will be notified to parties through the website
           established by ABN AMRO Rothschild. Parties should regularly check
           the website as placement of information thereon will be deemed to be
           notice of any change to these Bidding Rules.

     5.2   These Bidding Rules shall be governed and construed in accordance
           with the Governing Laws and all parties submit to the non-exclusive
           jurisdiction of the New Zealand courts.
<PAGE>

                                 ATTACHMENT I
                             INDICATIVE TIMETABLE

     1999

     15 January      Information Memorandum and Bidding Rules

      3 February     Indicative non-binding bids and supporting information due

      5 February     Short-listed Bidders notified of admission in Final Bid
                     Process 

                     Due diligence commences: CD-Roms provided to Bidders (and
                     access to Data Room)

                     Forms of Sale and Purchase Agreement and Standstill
                     Agreement made available to Bidders

     13 February     Bidder's profile for Offering Documents due

     22 February     Draft IPO Offering Documents made available to Bidders


     22 February     Bidder's comments on Sale and Purchase Agreement and
                     Standstill Agreement due and the final date for Bidders to
                     advise details and identity of intending Bidding Groups and
                     any relevant proposed arrangements, and the final date for
                     Bidders to advise details and identity of intending
                     purchaser entities.

     24 February     New Zealand prospectus made available to Bidders.

     26 February     Bidder's comments on strategic vision for Contact and any
                     other comments on Offering Documents due

     5 March         Final versions of Sale and Purchase Agreement and
                     Standstill Agreement provided to Bidders

     12 March        Last day for any final due diligence queries

     20 March        Submission of final binding Bids due

     Week beginning  Crown approves selected Bidder 
     22 March
<PAGE>
 
                                 ATTACHMENT II

                   FORM OF INDICATIVE NON-BINDING BID LETTER
                            (on Bidder's letterhead)

[date]


ABN AMRO Rothschild
Level 11, Castrol House
36 Customhouse Quay
Wellington
NEW ZEALAND

For:   Peter Bird/Liz Kelly

Contact Energy Limited

We wish to conduct due diligence investigations and discussions with the
management of Contact Energy Limited ("Contact") with a view to submitting a
final bid for the purchase of 40 per cent of the issued shares in Contact
("Shareholding") from the Crown. Based on our investigations to date, we believe
we would be prepared to acquire the Shareholding for a total price of 
NZ$[         ]. This is an indicative non-binding bid.

We agree/our Bidding Group agrees to be bound by the Bidding Rules for the sale
of the Shareholding dated January 1999.

This letter is solely an indication of interest and a request to be admitted
into the Final Bid Process. It does not constitute an offer or commitment on our
part to submit a final bid at a future time, and, except for agreeing to be
bound by the Bidding Rules, is not intended to have any legal effect.

Attached is the additional information requested per section 2.3 of the Bidding
Rules.

Yours faithfully


___________________________
(Title)
<PAGE>
 
                                ATTACHMENT III

                               FORM OF BID BOND


______________________________________________________________________ of
______________________________ (the "Bidder") has submitted a final bid to
purchase 40 per cent of the shares in Contact Energy Limited ("Contact") (the
"Shareholding").

In terms of the bidding rules issued by Her Majesty the Queen in right of New
Zealand (the "Crown") for the sale of the Shareholding dated January 1999 (the
"Bidding Rules") the Bidder is bound and obliged to furnish a Bid Bond along
with the final bid to secure certain obligations of the Bidder as set out
therein ("Obligations");

At the request of the Bidder, we _____________________________________ of
____________________ having our registered office at ___________________________
have agreed to give such a Bid Bond.

WE HEREBY irrevocably undertake and are bound and obliged to pay to the Crown
unconditionally and upon demand any sum or sums up to a maximum amount of NZ$25
million.

Every demand under this Bid Bond shall be in writing and signed by the New
Zealand Minister of Finance (or by any person acting under a delegated authority
from him) and shall be accompanied by a statement to the effect that the Bidder
has failed and/or neglected to perform its Obligations. For all purposes
connected with and relating to this Bid Bond, every demand shall be conclusive
proof that the amount so demanded is lawfully due under this Bid Bond and we
shall make payment without reference to the Bidder and notwithstanding any
notice given by the Bidder not to pay the same.

All payments under this Bid Bond shall be made in New Zealand by bank cheque or
bank draft drawn in favour of the Crown and in New Zealand dollars.

This Bid Bond shall remain valid and binding on us and shall continue until the
date on which the Crown advises us in writing that this Bid Bond is no longer
required by it or 31 October 1999 (whichever the earlier) PROVIDED HOWEVER that
we may, at any time, without being required to do so, pay to the Crown the said
sum of NZ$25 million less any amount or amounts we may have previously paid
under this Bid Bond or such lesser sum as may be specified by the Crown and
thereupon our liability under this Bid Bond shall terminate.

This Bid Bond shall be governed by the laws of New Zealand and we submit to the
nonexclusive jurisdiction of the New Zealand courts.

Dated this _____ day of _____________ 1999.

    [executed and witnessed as a deed]
<PAGE>
 
                                 ATTACHMENT IV

                            VERIFICATION CERTIFICATE

TO:  The Members of the Contact Energy Limited Due Diligence Committee
     Contact Energy Limited
     Directors of Contact Energy Limited
     The Crown

I confirm that:

1.   I have prepared the profile (and any additional information) attached to
     this certificate (the "extract") and I have read the section on Contact's
     strategic vision (also attached) from the draft dated [          ] 1999 of
     the Contact Energy Limited Prospectus (the "strategy section");

2.   The statements contained in the extract are true and not misleading and I
     also confirm that [the Purchaser has no/neither the Purchaser nor the
     Guarantor has any] significant differences in strategic vision for Contact
     Energy Limited to that outlined by Contact Energy Limited in the strategy
     section.

3.   No matters have been omitted from the extract or from our confirmation on
     the strategy section which would make any of the statements contained in
     the extract, or the strategy section, untrue or misleading in the context
     of the international and Australasian public offering of 60% of the Shares
     in Contact Energy Limited.

4.   The extract may be used in any offering documents relating to the
     international and Australasian public offering of 60% of the Shares in
     Contact Energy Limited to be published on or around April 1999.

5.   Where possible, I have attached references to independent external material
     which support each of the statements contained in the extract.

6.   I acknowledge that the parties listed above will rely on this certificate,
     which I give for and on behalf of [the Purchaser[and the Guarantor]].


Bidder's Name:                ____________________________

Duly Authorised Signatory:    ____________________________

Full Name of Signatory:       ____________________________

Senior Position Held:         ____________________________

Date:                         ____________________________
<PAGE>
 
                                  SCHEDULE 5

CAPITAL EXPENDITURE PROJECTIONS

<TABLE> 
<CAPTION> 
                                1999    2000    2001    2002    2003    2004    2005    
<S>                           <C>      <C>     <C>     <C>     <C>     <C>     <C> 
Geothermal (1)                         
Steam Winning ($000s)           2.09            3.84            2.65            0.92
Reinjection ($000s)                                                             9.11
Station Misc ($000s)            0.50    0.75    0.75    0.75    0.75    0.75    0.75
RMA Reconsent                   0.84    0.84   ---- Costs associated with preparing and progressing RMA consents
                                       
Total Geothermal                3.43    1.59    4.59    0.75    3.40    0.75   10.78 
                                       
Thermal                                
Otahuhu B                      57.60    1.03   ---- Assumes all retensions are released if dispute is resolved 
Te Rapa                        38.40   ---- Full payment under Te Rapa EPC
                                       
Total Thermal                  96.00    1.03    0.00    0.00    0.00    0.00    0.00
                                       
Hydro (2)                              
Stator Repairs                                                  3.13            3.22
Stator Coolers                                  0.13    0.13    0.27    0.27   ---- Upgrade stator cooling in order to prolong life
Transformers                                    0.37    3.85    0.83   ---- Enhancement/replacement of transformers
Elec/Mech                                                                       1.24
Sluice                          0.23    1.23   ---- Refurbishment of sluice gates
Gantry                          3.00   ---- Undertake remedial work in order to enhance dam safety
Clutha Reconsents               1.20    1.70   ---- Costs associated with preparing and progressing RMA consents
Clyde Division Sluice Gates             2.00    2.00   ---- Cost of new division sluice gates
                                       
Total Hydro                     4.43    4.93    2.50    3.98    4.23    0.27    4.46
                                       
Total Generation              103.86    7.55    7.09    4.73    7.63    1.02   15.24
                                       
Otahuhu B major maintenance                            17.42                   12.54
                                       
Retail Acquisitions                    
Fixed Assets                    5.50   ---- Retail acquisitions undertaken between 1 October 1998 and 31 March 1999 
Goodwill                      172.02   ---- Retail acquisitions undertaken between 1 October 1998 and 31 March 1999 
Meters                         58.86   ---- Retail acquisitions undertaken between 1 October 1998 and 31 March 1999 
Ongoing Meters                  1.50    2.00    2.00    2.00    2.00    2.00    2.00
                                       
Total Retail                  237.88    2.00    2.00    2.00    2.00    2.00    2.00
                                       
Other Capex                     1.00    0.50    0.50    0.50    0.50    0.50    0.50
                                       
Total Capital Expenditure     342.74   10.05    9.59    7.23   10.13    3.52   17.74
                                       
Investment Expenditure                  7.00   ---- Equity contribution for Oakey
                                       
<CAPTION>                              
                                2006    2007    2008    2009    2010 
<S>                           <C>      <C>     <C>     <C>     <C>     
Geothermal (1)                  
Steam Winning ($000s)                   2.21    3.02   ---- New drilling activities to secure new steam supplies (does not include 
                                                            deep drilling at Obaaki) 
Reinjection ($000s)             2.78   ---- Full reinjection of separated liquid may be a new requirement for RMA consents
Station Misc ($000s)            0.75    0.75    0.75   ---- Unspecified on-going capital expenditure
RMA Reconsent                 
                               
Total Geothermal                3.53    2.96    3.77    0.00    0.00
                               
Thermal                         
Otahuhu B                     
Te Rapa                       
                              
Total Thermal                   0.00    0.00    0.00    0.00    0.00
                              
Hydro (2)                       
Stator Repairs                  3.27    3.32    3.37    3.42    3.47  ---- Assumes old stators replaced with new
Stator Coolers                
Transformers                    
Elec/Mech                       1.2     1.23    1.25    1.35    1.5   ---- Enhancement/replacement of transformers
Sluice                        
Gantry                        
Clutha Reconsents             
Clyde Division Sluice Gates   
                              
Total Hydro                     4.47    4.55    4.62    4.77    4.97
                              
Total Generation                8.00    7.51    8.39    4.77    4.97
                              
Otahuhu B major maintenance                    17.39   ---- Cost of major plant maintenance as per O&M agreement with EPC contractor
                              
Retail Acquisitions           
Fixed Assets                  
Goodwill                      
Meters                        
Ongoing Meters                  2.00    2.00    2.00    2.00    2.00  ---- Initial estimate for meter replacement
                              
Total Retail                    2.00    2.00    2.00    2.00    2.00
                               
Other Capex                     0.50    0.50    0.50    0.50    0.50  ---- Unspecified ongoing capital expenditure
                              
Total Capital Expenditure      10.50   10.01   10.89    7.27    7.47
                              
Investment Expenditure         
</TABLE> 

(1)  In the event more onerous consent conditions are imposed with reconsenting
     Wairakei, management expects there may be future capital expenditure which
     has not yet been assessed.

(2)  There may also be future capital expenditure required to monitor the
     Roxburgh land slide. Again, no estimates are available and preliminary
     investigations indicate minimal movement of the slide.
<PAGE>
 
                               SCHEDULE 6

      1. Purchaser:        EDISON MISSION ENERGY TAUPO LIMITED

      2. Guarantor:        EDISON MISSION ENERGY 

      3. Purchase Price:   NZ$ 1,208,000,000.00
         (ONE BILLION, TWO HUNDRED AND EIGHT MILLION NEW ZEALAND DOLLARS)

      4. Notice Details:

         Purchaser Address for Service: Bell Gully Buddle Weir
                                        IBM Centre
                                        171 Featherston St.
                                        PO Box 1291
                                        Wellington

         Purchaser Facsimile: 0065 836 0879

         Guarantor Address For Service: Bell Gully Buddle Weir
                                           IBM Centre
                                           171 Featherston St.
                                           PO Box 1291
                                           Wellington

         Guarantor Facsimile: 0065 836 0879

      5. Purchaser's and Guarantor's Agent For Service in New Zealand:


         Name:    Bell Gully Buddle Weir

         Address: IBM Centre
                  171 Featherston St.
                  PO Box 1291
                  Wellington

      6. Date and party to Confidentiality Deed:

         Party: Edison Mission Energy Holdings Pty Ltd

         Date:  14 January 1999
<PAGE>
 
              CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

    I, Michael Kelland, of Singapore, Business Development Director, certify
    that:

    1.    BY deed dated the 19th day of March 1999, Edison Mission Energy Taupo
          Limited a company duly incorporated in New Zealand (the "grantor"),
          appointed me its attorney on the terms and subject to the conditions
          set out in the said deed;

    2.    AT the date of this certificate I have not received any notice or
          information of the revocation of that appointment by the commencement
          of the liquidation of the grantor, the removal of the grantor from the
          register or otherwise; and

    3.    I have executed the attached document in the name of the grantor in my
          capacity as its attorney under the powers conferred by the said deed.

    SIGNED at Wellington this 24th day of March 1999

     /s/ MICHAEL KELLAND
    -------------------------
    Michael Kelland
<PAGE>
 
              CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

    I, Michael Kelland, of Singapore, Business Development Director, certify
    that:

    1.    BY deed dated the 17th day of March 1999, Edison Mission Energy a
          company duly incorporated in the United States of America (the
          "grantor"), appointed me its attorney on the terms and subject to the
          conditions set out in the said deed;

    2.    AT the date of this certificate I have not received any notice or
          information of the revocation of that appointment by the commencement
          of the liquidation of the grantor, the removal of the grantor from the
          register or otherwise; and

    3.    I have executed the attached document in the name of the grantor in my
          capacity as its attorney under the powers conferred by the said deed.

    SIGNED at Wellington this 24th day of March 1999

     /s/ MICHAEL KELLAND
    -------------------------
    Michael Kelland
<PAGE>
 
              CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

    I, Gerard Loughman, of California, United States of America, Company
    Director, I certify that:

    1.    BY deed dated the 19th day of March 1999, Edison Mission Energy Taupo
          Limited a company duly incorporated in New Zealand (the "grantor"),
          appointed me its attorney on the terms and subject to the conditions
          set out in the said deed;

    2.    AT the date of this certificate I have not received any notice or
          information of the revocation of that appointment by the commencement
          of the liquidation of the grantor, the removal of the grantor from the
          register or otherwise; and

    3.    I have executed the attached document in the name of the grantor in my
          capacity as its attorney under the powers conferred by the said deed.

    SIGNED at Wellington this 24th day of March 1999

     /s/ GERARD LOUGHMAN
    -------------------------
    Gerard Loughman
<PAGE>
 
               CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

    I, Gerard Loughman, of California, United States of America, Company
    Director, certify that:

    1.    BY deed dated the 17th day of March 1999, Edison Mission Energy a
          company duly incorporated in the United States of America (the
          "grantor"), appointed me its attorney on the terms and subject to the
          conditions set out in the said deed;

    2.    AT the date of this certificate I have not received any notice or
          information of the revocation of that appointment by the commencement
          of the liquidation of the grantor, the removal of the grantor from the
          register or otherwise; and

    3.    I have executed the attached document in the name of the grantor in my
          capacity as its attorney under the powers conferred by the said deed.

    SIGNED at Wellington this 24th day of March 1999

    /s/ GERARD LOUGHMAN
    -------------------------
    Gerard Loughman
<PAGE>
 
              CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

      I, Michael Kelland, of Singapore, Business Development Director, certify
      that:

       1.  by deed dated the 19th day of March 1999, Edison Mission Energy Taupo
           Limited, a company duly incorporated in New Zealand (the "grantor"),
           appointed me its attorney on the terms and subject to the conditions
           set out in the said deed;

       2.  at the date of this certificate I have not received any notice or
           information of the revocation of that appointment by the commencement
           of the liquidation of the grantor, the removal of the grantor from
           the register or otherwise; and

       3.  I have executed the attached document in the name of the grantor in
           my capacity as its attorney under the powers conferred by the said
           deed.

       SIGNED at Wellington this 20th day of March 1999.

        /s/ MICHAEL KELLAND 
       -------------------------
       Michael Kelland
<PAGE>
 
          CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

     I, Gerard Loughman, of California, United States of America, Company
     Director, certify that:

     1.  by deed dated the 19th day of March 1999, Edison Mission Energy Taupo
         Limited, a company duly incorporated in New Zealand (the "grantor"),
         appointed me its attorney on the terms and subject to the conditions
         set out in the said deed;

     2.  at the date of this certificate I have not received any notice or
         information of the revocation of that appointment by the commencement
         of the liquidation of the grantor, the removal of the grantor from the
         register or otherwise; and

     3.  I have executed the attached document in the name of the grantor in my
         capacity as its attorney under the powers conferred by the said deed.

     SIGNED at Wellington this 20th day of March 1999.

      /s/ GERARD LOUGHMAN
     -------------------------
     Gerard Loughman
<PAGE>
 
              CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

     I, Michael Kelland, of Singapore, Business Development Director, certify
     that:

     1.  by deed dated the 17th day of March 1999, Edison Mission Energy, a
         company duly incorporated in the United States of America (the
         "grantor"), appointed me its attorney on the terms and subject to the
         conditions set out in the said deed;

     2.  at the date of this certificate I have not received any notice or
         information of the revocation of that appointment by the commencement
         of the dissolution of the grantor, or otherwise; and

     3.  I have executed the attached document in the name of the grantor in my
         capacity as its attorney under the powers conferred by the said deed.

     SIGNED at Wellington this 20th day of March 1999.

      /s/ MICHAEL KELLAND
     -------------------------
     Michael Kelland
<PAGE>
 
              CERTIFICATE OF NON-REVOCATION OF POWER OF ATTORNEY

     I, Gerard Loughman, of California, United States of America, Company
     Director, certify that:

     1.  by deed dated the 17th day of March 1999, Edison Mission Energy, a
         company duly incorporated in the United States of America (the
         "grantor"), appointed me its attorney on the terms and subject to the
         conditions set out in the said deed;

     2.  at the date of this certificate I have not received any notice or
         information of the revocation of that appointment by the commencement
         of the dissolution of the grantor, or otherwise; and

     3.  I have executed the attached document in the name of the grantor in my
         capacity as its attorney under the powers conferred by the said deed.

     SIGNED at Wellington this 20th day of March 1999.

      /s/ GERARD LOUGHMAN
     -------------------------
     Gerard Loughman