Tracor was a major North American efence electronics contractor which was acquired by Marconi Electronic Systems (MES), a subsidiary of GEC 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.