The Navy selected Hughes Aircraft Co. Friday to build a new fleet communications satellite network for an estimated $1 billion, the service announced.

The subsidiary of General Motors, which is based in El Segundo, Calif., won the competition to build and launch up to ten UHF communications satellites by September 1996 over TRW, Inc. and RCA Corp., which is part of General Electric Co.The network will provide communications between ships at sea and Navy land installations, the Navy said, and will replace a network of three Navy-owned satellites and three leased units.