New York--General Dynamics Corp. late last week called off its $2.1 billion bid for Newport News Shipbuilding Inc., ending a second attempt to purchase its ship building rival. Early last week the Justice Department filed a lawsuit seeking to block General Dynamics' bid for Newport. The lawsuit came after the Defense Department said it favored a competing offer from Northrop Grumman Corp. The Pentagon had blocked the deal citing concerns that it would leave the nation with only one builder of nuclear ships. With General Dynamics out of the picture, the way is now clear for Northrop to pursue its bid.