Associated Electrical Industries

Associated Electrical Industries (AEI) was a British holding company formed in 1928 through the merger of the British Thomson-Houston Company (BTH) and Metropolitan-Vickers electrical engineering companies. In 1967 AEI was acquired by GEC, to create the UK's largest electrical group. A scandal that followed the acquisition is said to have been instrumental in reforming accounting practices in the UK.

Main subsidiaries

 * Metropolitan-Vickers (Metrovick)
 * British Thomson-Houston Company (BTH)
 * Ferguson, Pailin & Co (switchgear)
 * Edison Swan (lamps and radio valves)
 * Siemens Brothers & Co (cables, telephone equipment and railway signaling apparatus)
 * Hotpoint (domestic appliances)
 * W.T. Henley (cables, insulators and low voltage switchgear)
 * Newton Victor (X-ray machines)
 * Sunvic Controls (heating controls)
 * Birlec (industrial electric furnaces)
 * International Refrigerator Company

Takeover and restructuring
Rivalry existed between Metrovick and BTH brands in the Electrical Engineering field, resulting in internal competition and duplicated management. In 1959 AEI decided to remove those brands and consolidate both as AEI brands, resulting in internal problems and a fall in sales and market value. The abandonment of two well known trademarks and the replacement with the unfamiliar AEI branding lost the company significant work to competitors and resulted in a market weakening of the company.

These problems paved the way for a takeover in 1967 with the recently restructured General Electric Company plc (GEC) under Arnold Weinstock. The following year GEC merged with English Electric.

GEC later went through substantial restructuring, including in 1989 forming GEC ALSTHOM and Cegelec Projects. GEC ALSTHOM was created from the GEC's Power and Transport businesses (originally AEI (previously BTH and Metrovick) and English Electric) and the French Compagnie Générale d'Electricité (CGE). The merger was to enable both companies a gain a greater export potential into Europe.

The GEC facilities in Rugby were split into GEC Alstom and Cegelec Projects, but in 1998 the two companies were reunited under the Alstom banner.