FALLS CHURCH, Va. – General Dynamics said Monday it is extending its pending tender offer for shares of Newport News Shipbuilding common stock.

The Falls Church-based defense contractor extended its offer until midnight July 20. The earlier deadline was July 6, and General Dynamics says about 20.3 million Newport News shares were tendered by then.

The number of Newport News shares tendered is more than a majority of its 31.4 million shares outstanding, and General Dynamics said it is awaiting government approval to complete the acquisition.

In a merger worth $2.1 billion, General Dynamics – the owner of Bath Iron Works in Maine – is offering $67.50 per share for the shipyard, which designs and constructs nuclear-powered aircraft carriers and submarines for the Navy and services ships in the Navy fleet.

Los Angeles-based Northrop Grumman, General Dynamics’ primary rival for Navy shipbuilding contracts, also has offered $2.1 billion for Newport News, giving shareholders the opportunity to sell their shares for $67.50 each or exchange them for shares of Northrop Grumman.