Bath Iron Works was sold for about $500 million.

The shipbuilding subsidiary of Congoleum Corp.--one of the Navy’s biggest suppliers of cruisers and destroyers--was acquired by an investment group headed by Gibbons, Green, van Amerongen Ltd. The announcement was made by BIW President William E. Haggett, who declined to disclose the purchase price, but published reports estimated the value of the buyout at $500 million. BIW is Maine’s largest private employer with 7,000 employees at yards in Bath and Portland.