Willbros Group (WG)

Joint Venture

In connection with the Company’s 10% interest in a joint venture in Venezuela, the Company issued a corporate guarantee equal to 10% of the joint venture’s outstanding borrowings with two banks. The guarantee decreases as borrowings are repaid. As of March 31, 2006, the maximum amount of future payments the Company could be required to make under this guarantee is approximately $2,133. The guarantee to the two banks terminated with the August 2006 closing of the sale of the Venezuelan operations and assets.

99.4-9

WILLBROS GROUP, INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(In thousands, except share and per share amounts)

(Unaudited)

2. Discontinuance of Operations and Asset Disposal (continued)

Joint Venture

In connection with the Company’s 10% interest in a joint venture in Venezuela, the Company issued a corporate guarantee equal to 10% of the joint venture’s outstanding borrowings with two banks. The guarantee decreases as borrowings are repaid. As of December 31, 2005, the maximum amount of future payments the Company could be required to make under this guarantee is approximately $2,106. The Company anticipates its guarantee to the two banks would terminate with the closing of the sale of the Venezuelan operations and assets.

Joint Venture

In connection with the Company’s 10% interest in a joint venture in Venezuela, the Company issued a corporate guarantee equal to 10% of the joint venture’s outstanding borrowings with two banks. The guarantee decreases as borrowings are repaid. As of June 30, 2006, the maximum amount of future payments the Company could be required to make under this guarantee is approximately $1,863. The Company anticipates its guarantee to the two banks would terminate with the closing of the sale of the Venezuelan operations and assets.