Press Release Details

OAK BROOK, Ill., Feb. 9, 2007 (PRIME NEWSWIRE) -- Great Lakes Dredge & Dock Corporation (NasdaqGM:GLDD - News)(NasdaqGM:GLDDW - News) today announced that it will release its financial results for the fourth quarter and year ended December 31, 2006 on Friday February 16, 2007 at 7:00 a.m. C.S.T. A conference call with the Company will be held the same day at 10:00 a.m. C.S.T. to discuss the Company's fourth quarter and year end results and review operational highlights and other business developments. The call-in number is 800-361-0912. The call can also be heard on the Great Lakes website, http://www.gldd.com under Events and Presentations on the investor relations page. The conference call will be available by replay for two weeks, by calling 888-203-1112 and providing passcode 4183191. A copy of the press release will be available on the Company's website.

Great Lakes Dredge & Dock Corporation is the largest provider of dredging services in the United States and the only U.S. dredging company with significant international operations, averaging 16% of the Company's total revenue over the last three years. Great Lakes is a leader in each of the U.S. markets in which it competes: capital, maintenance and beach nourishment dredging. Great Lakes also owns an 85% interest in North American Site Developers, Inc., one of the largest U.S. providers of commercial and industrial demolition services. Additionally, the Company owns a 50% interest in a marine sand mining operation in New Jersey which supplies sand and aggregate used for road and building construction. Great Lakes has a 116-year history of never failing to complete a marine project and owns the largest and most diverse fleet in the industry, comprising over 180 specialized vessels.



Contact:

Great Lakes Dredge & Dock Corporation

Deborah A. Wensel,

Chief Financial Officer

(630) 574-3772