Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 132,953 pages of information and 210,198 images on early companies, their products and the people who designed and built them.
Associated Electrical Industries. A.E.I.
1926 Gerard Swope, president of General Electric (U.S.A), proposed that BTH, Westinghouse, GEC and the English Electric Co should amalgamate but Hugo Hirst of GEC was not interested in Swope’s scheme.
1928 Associated Electrical Industries (AEI)  was established, with Howard C. Levis (chairman of BTH) as chairman, as a result of the merger of Metropolitan-Vickers and its rival British Thomson-Houston (BTH), a company of similar size and product lineup. Combined, they would be one of the few companies able to compete with Marconi's Wireless Telegraph Co or the English Electric Co on an equal footing. Also included in the new group were Edison Swan Electric Co (Ediswan) and Ferguson Pailin of Openshaw, Manchester (which BTH had been in the process of buying in 1928). Several of the directors of Metropolitan-Vickers resigned to become directors of the subsidary Metropolitan-Vickers Electrical Co Ltd. The group had almost 30,000 employees.
The new group was handicapped by poor communication and intense rivalry between Metrovick and BTH, which remained as separately quoted companies and often worked at cross purposes to each other. AEI was never able to exert effective control over its two competing subsidiaries. Ediswan took on valve production whilst Metrovick ceased valve production; BTH took on radio set production and continued with special purpose valves for non-domestic purposes .
1929 The annual meeting was told that agreement had been reached with the International General Electric Co (USA) which meant that the whole group would be able to exchange patents and manufacturing information with GE (USA). Also, International General Electric Co. had significant financial interest in AEI, which it held as an investment with no suggestion that it wanted control.
1937 Frank Whittle's Power Jets company built the world's first prototype jet engine at the BTH works in Rugby. BTH had a major role in developing it. Development was later moved to the Lutterworth works, which were falling into disuse at the time. BTH's directors seemed sceptical of the design and offered little help.
WW2 BTH expanded north of the River Avon into the Boughton Road site to make magnetos for aircraft engines and other war products.
1940 BTH decided they were not really interested in making jet engines due to their commitment to electrical equipment. Rover was soon selected to make jet engines.
1944 The Lutterworth Power Jets work was nationalized.
1945 After World War II Oliver Lyttelton took over AEI, and started a massive expansion.
1947 The Hungarian scientist Dennis Gabor invented holography at the BTH site in Rugby.
1952 AEI's subsidiary Edison Swan Co purchased British Mechanical Productions and its subsidiary General Accessories Co, which made electrical accessories under the Clix brand and radio and television components, thereby filling a gap in AEI's range of products .
1952 The AEI Group consisted of:
1954 Acquired Birlec.
1954-1963 Lord Chandos was chairman of AEI.
1955 Four industrial groups formed to exploit the information being made available by UKAEA on design of nuclear power "furnaces" - Industrial Atomic Energy Group involving AEI and John Thompson with electrical generating expertise from Metropolitan-Vickers and BTH. Other groups were English Electric Co and Babcock and Wilcox; C. A. Parsons and Co and Head, Wrightson and Co; GEC and Simon-CarvesLtd .
1956 The main companies in the AEI Group were:
1957 The massive new £8 million turbine works was opened at Larne as a result.
1957 or after: BTH won the contract to build the new Buenos Aires power station, valued at £35 million. Rivalries intensified with Metrovick. Lyttelton continued to try to reduce this friction, leading to several unsuccessful reorganizations and slipping profits.
1958 Reorganisation of the group started with the aim of bringing the 3 subsidiary companies into one with the AEI name used throughout; the subsidiaries would cease to be separate trading companies; the 3 operating companies would be:
The directors formed two AEI product divisions:
1959 Further product divisions were created:
1959 Acquired Associated Insulation Products and W. T. Henleys Telegraph Works Co, and London Electric Wire Co and Smiths  but London Electric was treated as a "supply company" rather than a division.
1959 Image. Headquarters of A.E.I. Electronic Division, New Parks, Leicester.
1960 Jan 1st. Reorganisation essentially complete. AEI stopped using the names BTH and Metrovick. The 3 main manufacturing companies were reorganised into product divisions of AEI: Turbine Generator, Transformer and Switchgear, as well as Construction.. Other product divisions included:
In addition there were other specialised subsidiary companies such as AEI-Hotpoint.
This led to a huge falling-off in sales because no-one in the heavy electrical industry was familiar with "AEI"; a massive drop in AEI's stock price followed. Continued attempts to streamline what was two separate management structures continued to fail and by the mid-60's the entire AEI empire was in financial trouble.
1960 Advert. Generators, motors, rheostat and electronic control gear, switchgear, transformers, rectifiers, helical gearing etc. 
1960. An AEI research lab was built at Rugby (building BR57 in the Boughton Road site).
1960 A consortium of AEI, Automatic Telephone and Electric Co, Ericsson TelephonesLtd, GEC, Marconi's Wireless Telegraph Co, Plessey Co and STC formed a holding company Combined Telephone Holdings only days after its members had failed in their bid to acquire Telephone Manufacturing Co. Combined Telephone Holdings purchased for cash more than half of the shares in Phoenix Telephone and Electric Works and offered to purchase the rest.
1960 Heavy electrical plant advertised under the AEI brand. Heavy plant division at Rugby and Manchester.
1960 AEI formed a new management company, AEI Appliances, to control AEI-Hotpoint and AEI-Gala, the export business of Hotpoint.
1961 Britain's largest electrical manufacturer covered a wide range of manufacture, design and distribution; AEI had 103,450 employees with works in more than 50 UK towns.
1962 Commissioning of Britain's first commercial nuclear power facility at Berkeley.
1963-1967 Construction and commissioning of the £25M radar dish at Chilbolton Observatory.
1967 Supplied the turbine generators for Eggborough power station
1967 GEC bought AEI outright. GEC thus became the UK's largest electrical group.
1968 Supplied turbo-alternator for the Winfrith power station
1969 Marconi Radar Systems Ltd (MSRL) was formed from GEC-AEI Electronics (Blackbird Road and New Parks, Leicester), Marconi's Radar Division (Chelmsford) and Elliott's Aerospace Control Division.
1980s GEC Rugby shrank. Many buildings were pulled down. The area west of the Black Path became a supermarket site. The Boughton Road site became several separate small firms.
1989 GEC Rugby was split into GEC Alsthom and Cegelec Projects.
1998 GEC Alsthom and Cegelec Projects were reunited as Alstom.
2007 The firm's clubhouse on Hillmorton Road was pulled down, and its surrounding sports field was used for house building along its south edge.
See Jet Engines
See Lamps and Valves
See BTH: Magnetos
See AEI: Traction