GEC Plessey Telecommunications (GPT) was a British manufacturer of telecommunications equipment, notably the System X telephone exchange. The company was founded in 1988 as a joint venture between GEC and the British electronics, defence and telecommunications company Plessey. The next year, after a joint holding company of GEC and the German conglomerate Siemens AG acquired Plessey, GPT was converted into a 60/40 GEC/Siemens joint venture. The GPT name ceased to be used in the mid-1990s, and in 1998 the company was amalgamated into Siemens Communications.