Willbros Commences Consent Solicitation on Convertible Senior Notes

Willbros Group says it is soliciting consents from the holders of its outstanding 2.75% convertible senior notes due 2024 to amend certain provisions in the indenture governing the notes. By consenting to the proposed amendments to the indenture, holders of the notes will also be consenting to waive any potential defaults that may have occurred before the proposed amendments become effective, to rescind a purported notice of default that was delivered to Willbros under the indenture and to clarify that for a period ending on the nine-month anniversary of the date the proposed amendments become effective, no default will occur if Willbros fails to timely file a periodic report with the SEC. Approval of the proposed amendments and waiver requires the consent of the holders of a majority in principal amount of the outstanding notes. The record date for the solicitation is September 6, 2005.

The proposed amendments provide that:

* the initial date on or after which Willbros may redeem all or any portion of the notes will change from March 15, 2011 to March 15, 2013; and

* in the event of a fundamental change involving a sale of Willbros in which at least 10 percent of the sales proceeds are paid in cash, Willbros will pay a make-whole payment to the holders of the notes. The make-whole payment will consist of no more than the present value of two years of scheduled interest payments on the notes. No separate cash fee is being paid to holders for delivering consents. Willbros previously announced that it would not be able to timely file its annual report on Form 10-K for the year ended December 31, 2004 and its quarterly reports for the periods ended March 31, 2005 and June 30, 2005, and Willbros has not filed them to date. On June 10, 2005, Willbros received a letter from a representative of Whitebox Advisors, LLC asserting that, as a result of Willbros' failure to timely file with the SEC its 2004 Form 10-K and Quarterly Report on Form 10-Q for the quarter ended March 31, 2005, Whitebox Advisors was placing Willbros on notice of an event of default under the indenture. Willbros has previously indicated that it does not believe that it has failed to perform its obligation under the indenture.

On August 19, 2005, Willbros reached an agreement with Whitebox Advisors, the beneficial owner of approximately 25.1% of the notes as of June 10, 2005, pursuant to which it agreed to prepare an amendment to the indenture and solicit approval for the proposed amendments and waiver. Whitebox Advisors has agreed to deliver a letter of consent in favor of the proposed amendments and waiver.

The solicitation expires at 5:00 p.m., New York City time, on September 21, 2005, unless extended by Willbros. Willbros will announce any extensions of the solicitation by press release no later than 9:00 a.m., New York City time, the day after expiration of the solicitation.