Northrop Grumman Corp. has won contracts to supply shipbuilding and airborne communication services to two U.S. military branches.

The Los Angeles defense contractor said late Monday its shipbuilding unit’s Amsec LLC subsidiary won part of a five-year shipbuilding contract, worth $455 million, with the Navy to provide hull, mechanical, electrical and electronic system alteration and installation services. The company was not specific on what its share will be, but said the work will be performed at several naval installations on both coasts and Hawaii.

Separately, the Pentagon announced that Northrop received a $35.5 million contract from the Air Force to supply and support battlefield airborne communication systems, but did not provide specifics.

Northrop shares were down 7 cents, or less than 1 percent, to $49.21 in midday trading on the New York Stock Exchange.