In 1969 under Robert Telford, Managing Director of GEC-Marconi Electronics, four new market oriented management companies were established each covering the activities of a group of existing GEC-Marconi companies. As a result the Company became Marconi-Elliott Avionic Systems Ltd comprising the Rochester and Borehamwood activities of Elliott Flight Automation, Elliott-Automation Radar Systems and the Basildon activities of the Marconi Aeronautical Division together with the Electro-Optical Systems Division. Dr Bernard O’Kane was Managing Director with Jack Pateman as Deputy Managing Director
In 1969 again the company was renamed Marconi-Elliott Avionics and in 1978 the company was renamed Marconi Avionics Ltd.
There was steady growth to nearly 12,000 employees in 1982. The name was again changed to GEC Avionics Limited in September 1984 although it was not until four years later that the trading name of Elliott Bros London was finally dropped.
In 1993 yet again the company name changed to GEC-Marconi Avionics Ltd comprising the former GEC Avionics, GEC-Ferranti Defence Systems, GEC Sensors and GEC Aerospace businesses. This organisation was announced on 5 January 1993 and came into effect on 1 April 1993 and finally in 1998 it became Marconi Electronic Systems Ltd.
At the end of 1999 Marconi Avionics was absorbed into BAE SYSTEMS with the merger of British Aerospace and Marconi Electronic Systems.