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FIRST SUPPLEMENTAL AGREEMENT TOASSUMPTION AND
LOAN CONVERSION AGREEMENT

THIS AGREEMENT dated the 20th day of December, 2006,

AMONG:

AGOSTO CORPORATION LTD., a
company organized under the laws of the British Virgin Islands

(the "Lender")

AND:

DEERFIELD ENERGY LLC, a limited
liability company organized under the laws of the State of Delaware, U.S.A.

(the "Borrower")

AND:

BROCKTON CAPITAL CORP., a
company organized under the laws of the Province of British Columbia, Canada

(the "Company")

WHEREAS:

A. Pursuant to a promissory note dated August 11, 2006 the
Borrower borrowed the principal amount of US$500,000 (the "Loan") from
the Lender;

B. Pursuant to a Deed of Trust, Assignment of Production,
Security Agreement and Financing Statement effective as of August 11, 2006 (the
"Mortgage") granted by the Borrower for the benefit of the Lender, the
Borrower granted the Lender certain rights, titles, interests and estates in
certain assets and property of the Borrower (the "Security
Interests");

C. Pursuant to an Assumption and Loan Conversion Agreement
dated December 20, 2006 between the Lender, the Borrower and the Company, the
Company agreed to assume all of the liabilities and obligations of the Borrower
to the Lender in respect of the Loan; and

D. The Lender desires to assign, and the Company desires to
assume, all of the Lender's rights, titles, interests and estates in the
Security Interest all upon the terms and subject to the conditions set out
herein.

NOW THEREFORE THIS AGREEMENT WITNESSES THAT in
consideration of the premises, covenants, representations and warranties
contained herein, and for other good and valuable consideration (the receipt and
sufficiency of which is hereby acknowledged), the parties hereto covenant and
agree as follows:

|1. | The Lender hereby absolutely transfers, assigns and
      conveys to the Company, which accepts such transfer, as of and from the
      date hereof, all of the Lender's rights, titles, interests and estates in
      the Security Interest and all of the benefits and advantages of the Lender
      under the Mortgage.
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- 2 -

|2.  | The Borrower hereby records and confirms its consent to
      the assignment by the Lender to the Company of all of the Lender's rights,
      titles, interests and estates in the Security Interest and all of the
      benefits and advantages of the Lender under the Mortgage.                                                  
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|    |                                                                                                                                                                                                                                                                                                                                       
|3.  | The Lender represents and warrants to the Company that it
      has not previously transferred, assigned or conveyed any rights, titles,
      interests and estates of the Lender in the Security Interest.                                                                                                                          
|    |                                                                                                                                                                                                                                                                                                                                       
|4.  | This Agreement shall be governed by and construed in
      accordance with the laws of the Province of British Columbia.                                                                                                                                                                                                              
|    |                                                                                                                                                                                                                                                                                                                                       
|5.  | All covenants, agreements, representations and warranties
      made by the parties shall survive the completion of the transactions
      contemplated hereby.                                                                                                                                                                       
|    |                                                                                                                                                                                                                                                                                                                                       
|6.  | Each of the parties shall at all times and from time to
      time and upon reasonable request do, execute and deliver all further
      assurances, acts and documents for the purpose of giving full force and
      effect to the covenants, agreements, representations and warranties
      contained in this Agreement.         
|    |                                                                                                                                                                                                                                                                                                                                       
|7.  | This Agreement is not transferable or
  assignable.                                                                                                                                                                                                                                                                                   
|    |                                                                                                                                                                                                                                                                                                                                       
|8.  | The invalidity or unenforceability of any particular
      provision of this Agreement shall not affect or limit the validity or
      enforceability of the remaining provisions of this Agreement.                                                                                                                                  
|    |                                                                                                                                                                                                                                                                                                                                       
|9.  | This Agreement shall ensure to the benefit of and be
      binding upon the successors and assigns of the parties hereto, as
      applicable.                                                                                                                                                                                        
|    |                                                                                                                                                                                                                                                                                                                                       
|10. | This Agreement may be executed in several parts in the
      same form and by facsimile and such parts as so executed shall together
      constitute one original document, and such parts, if more than one, shall
      be read together and construed as if all the signing parties had executed
      one copy of this Agreement.

IN WITNESS WHEREOF the parties have duly executed this
Agreement as of the date first written above.

|AGOSTO CORPORATION LTD.   
|--------------------------
|                          
|Per: *"/s/ signed"*       
|Authorized
      Signatory
|                          
|DEERFIELD ENERGY LLC      
|                          
|Per: *"/s/ signed"*       
|Authorized
      Signatory
|                          
|BROCKTON CAPITAL CORP.    
|                          
|Per: *"/s/ signed"*       
|Authorized
      Signatory

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