BAE Systems is a London-based multinational defence, security and aerospace company with operations worldwide that is among the world's largest defence contractors. Its largest operations are in Britain and the United States, where its BAE Systems Inc subsidiary is one of the six largest suppliers to the US Department of Defense. BAE was formed from the 1999 merger of Marconi Electronic Systems (MES), the defence electronics and naval shipbuilding subsidiary of the General Electric Company (GEC), and British Aerospace (BAe) - an aircraft, munitions and naval systems manufacturer.