SHARE PURCHASE AGREEMENT
This Share Purchase Agreement (this “ Agreement ”) is made and entered into as of the 5 th day of June,
2007 (the “ Effective Date ”), by and among Willbros Acquisition Canada Limited , a company
incorporated under the laws of British Columbia, Canada (“ Purchaser ”); AMEC Inc. , a company
incorporated under the laws of Canada (“ AMEC ”); and AMEC Americas Limited, a company incorporated
under the laws of Canada (“ AMEC Americas ” and, collectively with AMEC, “ Sellers ” or, individually, each
a “ Seller ”).
A. Sellers own all of the issued and outstanding share capital of Midwest Management (1987) Limited, a
company organized under the laws of Saskatchewan, Canada (“ Midwest ”), which is engaged in the business of
pipeline construction contracting for the oil and gas industry (the “ Business ”).
B. Purchaser desires to acquire, and Sellers desire to sell, said share capital of Midwest.
C. Purchaser and Sellers (the “ Parties ”) desire to evidence their agreement to the terms and conditions of
the purchase and sale of said share capital of Midwest as set forth in this Agreement.
In consideration of the recitals and the representations, warranties and covenants set forth in this Agreement,
the Parties hereby agree as follows:
1.1 Defined Terms. As used in this Agreement, each of the following terms has the meaning specified below:
“ Accounts Payable ” means any and all trade accounts payable of the Midwest Group.
“ Adjustment Statement ” means a statement showing Current Assets, Current Liabilities, Working Capital,
Debt Load Adjustment and Other Liabilities Adjustment as of the Closing Date.
“ Affiliate ” means, with respect to any Person, each other Person that, directly or indirectly (through one or
more intermediaries or otherwise), controls, is controlled by, or is under common control with such Person. The
term “ control ” (including the terms “ controll