In 1988 a joint-venture was formed between the General Electric Company (GEC) with Compagnie Générale d’Electricité (CGE) that led to the establishment of an Anglo-French company, GEC Alsthom in 1989. This company encompassed the Power Generation and Transmission, Rail Transport (25%) businesses from the constituent companies of GEC and CGE. The GEC Alsthom company headquarters were based at Rugby, Warwickshire and the headquarters for Transport were based at Trafford Park in Manchester. GEC Alsthom purchased train builder Metro-Cammell based at Washwood Heath, Birmingham from the Laird Group in 1989, bringing into the group a company which had a long association with GEC Traction and its predecessors as a vehicle builder. In 1998 GEC Alsthom was re-formed and became Alstom with Transport / Alstom Transport one of its major divisions.

GEC Alsthom Traction was formed from the merger of GEC and Alcatel-Alsthom (formerly known as Compagnie Générale d’Electricité of France) in 1989, which created a Joint Venture of their Power Engineering businesses (Power Stations, Switchgear and Rail Transport). The UK headquarters of the traction business was based at Trafford Park in Manchester. GEC Alsthom purchased train builder Metro-Cammell based at Washwood Heath, Birmingham from the Laird Group in 1989, bringing into the group a company which had a long association with GEC Traction and its predecessors as a vehicle builder. GEC Alsthom Traction became part of the Transport Equipment Group (TEG) with the French sites Ornans (motors), Tarbes (control equipment) and Villeurbanne (electronic systems, converters and control equipment), later joined by ACEC Transport (Charleroi). A major project in this period was the design and build of the Trans Manche Super Train (TMST) for London. TMST, later known as Eurostar Class 373, was the first TGV with asynchronous traction drive, all TGVs until later Duplex fleets having DC or synchronous traction drives. It was designed for three voltages 750v DC for the UK Southern Region, 3000v DC for Belgium and 25kV for the tunnel and France, and later for HS1 high speed line from the tunnel to London. SNCF later added 1500v DC to 4 trains to allow the trains to run to the Alps. In 1993, as part of the rationalisation of the equipment group, it was announced that the headquarters of GEC Alsthom Traction would move to Preston, leaving only Power Module design and manufacture at Manchester, and a project team was set up at Preston for the regeneration of the Preston site, with the eventual closing of all activities at Trafford Park in 1998. At the same time, there was rationalisation of product lines in the equipment group, with inductors and auxiliary converters moving to Preston, traction motor design concentrated at Ornans, switchgear at Tarbes and electronic control systems at Villeurbanne. GEC Alsthom Traction became Alstom Traction on 22nd June 1998 and the company name survived to 19th August 2008 but was increasingly integrated within the Transport division of Alstom.

Associated Electrical Industries (AEI) was formed in 1928 as a financial holding company for a number of leading electrical manufacturing and trading companies in the United Kingdom. The two major constituent companies were British Thomson-Houston (BTH) based at Rugby, (Mill Road Works) and Metropolitan-Vickers Electrical Company Ltd (Metrovicks) situated at Trafford Park, Manchester. However, fierce rivalry existed between the Metrovick and BTH brands resulting in internal competition and duplicated management. This was highlighted during the Second World War in 1939, when Metrovicks and BTH became the first two firms in the world to construct jet engines (independently from each other). Following the Second World War, in 1954, AEI expanded to consist of BTH, Metrovicks, Edison Swan Electric Co, Ferguson Pailin, Hotpoint Electric Appliance Co, International Refrigerator Co, Newton Victor, Sunvic Controls, Premier Electric Heaters, Siemens Bros (1955) and Birlec (1954). In 1959 AEI decided to remove the familiar brands of BTH and Metrovicks and consolidate both as AEI resulting in internal problems and a fall in sales and market value. However, AEI acquired a variety of companies from 1959 to 1967, these included Associated Insulation Products, W. T. Henley’s Telegraph Works Co (1958), and London Electric Wire Co and Smiths (1958), Submarine Cables, Hackbridge Holdings Ltd., The Lancashire Dynamo and Crypto Ltd., W.T. Avery Ltd., Henley and Schreiber. The General Electric Company bought AEI in 1967.