BAE Systems plc (BAE) is a British multinational arms, security, and aerospace company based in London, England. It is the largest defence contractor in Europe, and ranked the seventh-largest in the world based on applicable 2021 revenues. As of 2017, it is the biggest manufacturer in Britain. Its largest operations are in the United Kingdom and United States, where its BAE Systems Inc. subsidiary is one of the six largest suppliers to the US Department of Defense. Other major markets include Australia, Canada, India, Saudi Arabia, Turkey, Qatar, Oman and Sweden, where Saudi Arabia is regularly among its top three sources of revenue. The company was formed on 30 November 1999 by the £7.7 billion purchase of and merger with Marconi Electronic Systems (MES), the defence electronics and naval shipbuilding subsidiary of the General Electric Company plc (GEC), by British Aerospace, an aircraft, munitions and naval systems manufacturer.