Marconi Communications, the former telecommunications arm of the General Electric Company plc (GEC), was founded in August 1998 through the amalgamation of GEC Plessey Telecommunications (GPT) with other GEC subsidiaries: Marconi SpA, GEC Hong Kong, and ATC South Africa.
During the mid-1990s, its prominent predecessor company, GPT, gradually disappeared. Through a series of mergers, divisions and restructuring in 1997-1998, GPT was amalgamated with two major companies: Marconi Communications and Siemens Communications (in 2008, Siemens Enterprise Communications).
In December 1999, it became the principal subsidiary of Marconi plc, which was formed by the renaming of the entity left out of GEC, when GEC’s defence arm, Marconi Electronic Systems, was merged with British Aerospace to form BAE Systems.
GEC acquired FORE System on April 26, 1999, near the peak of the dot-com bubble. The US$4.5bn ($6.5 billion today) price tag for FORE Systems took a heavy toll on Marconi following the burst of the dot-com bubble in 2000/2001. In July 2001 Marconi plc suffered a 54% drop in its share price following suspension of trading of its shares, a profits warning and redundancies. Marconi plc was restructured to Marconi Corporation plc in May 2003.
On 23 January 2006, Ericsson acquired a majority of Marconi Communications’ parent company, Marconi Corporation plc. The remainder of Marconi Corporation plc was renamed Telent plc.