U.S. specialty truck maker Oshkosh Corp (OSK.N) has won a $6.75 billion contract to build 17,000 light tactical vehicles to replace the aging Humvees used by the U.S. Army and Marine Corps, the U.S. Army announced on Tuesday. Oshkosh beat out a team made up of Lockheed Martin Corp (LMT.N) and Britain’s BAE Systems Plc (BAES.L), as well as AM General, a privately held company that built the original Humvees, the Army said in a statement.