A General Dynamics sign is shown at the International Association of Chiefs of Police conference in San Diego, California, U.S. October 17, 2016. REUTERS/Mike Blake

WASHINGTON (Reuters) - The U.S. Defense Department said on Wednesday it had awarded contracts for submarine maintenance and modernization to General Dynamics Corp GD.N for $1.1 billion, to Huntington Ingalls Industries Inc HII.N for $874 million and to Oceaneering International Inc OII.N for $828 million.