Tracor was a major North American defense electronics contractor which was acquired by Marconi Electronic Systems (MES), a subsidiary of General Electric Company plc, in 1998. Following the purchase of MES by British Aerospace in November 1999 to form BAE Systems, Tracor became BAE Systems Integrated Defense Solutions. Following a 2005 reorganisation, the company became BAE Systems Sensor Integration, part of Electronics and Integrated Solutions.