From Graces Guide
The Associated Equipment Company was a manufacturer of commercial vehicles from 1912 to 1977.
See also -
1908 The company evolved from the merger of the London Motor Omnibus Co - which ran its "Vanguard" buses on services in the capital from their works at Walthamstow - and the mighty London General Omnibus Co (L.G.O.C.)
In the early 20th Century the chassis for London's buses were mainly imported; the enlarged L.G.O.C. built a bus chassis to its own design at Walthamstow Works.
1912 The L.G.O.C. was taken over by the Underground Electric Railways Co of London.
1912 The Underground Electric Railways Co (UERC) separated off the chassis-building activities to form the Associated Equipment Co better known as AEC.
A five-year agreement was made between AEC and Daimler, who became the sole agents for the AEC chassis sold to companies outside the UERC. The agreement came to a premature end in 1916 when AEC came under direct Government control for the duration of the war.
The majority of AEC vehicles up until 1925 were built for the L.G.O.C., although some models were supplied to provincial customers but in relatively small numbers
1925 Start of construction of new factory at Hanwell, west of London.
1926 AEC and Daimler merged to form the short-lived Associated Daimler Co which was to be floated so that it would be free of the financial control of L.G.O.C. and therefore would be able to supply other companies .
1927 The first Southall chassis were completed early in the year and over the next fifty-two years AEC were leaders in the highly competitive field of commercial and passenger vehicle manufacture, responsible for classics such as the Matador artillery tractor, the Regal, Regent and Reliance series of passenger chassis, the Mammoth Major, Mandator and Mercury heavy goods chassis, and diesel-engines as the 7.7, 8.8, 9.6, 11.3 and 12.4 litre types.
Many thousands of buses, lorries, dump trucks and chassis for fire appliances were built for customers at home and overseas. AEC engines were also used in many other makes of chassis, and there were military, marine and industrial engine applications too.
1928 Introduced a six-cylinder CI engine of their own design under the Acro licence and ran it experimentally.
1928 Became private company.
1929 Associated Daimler Co was de-merged into its 2 constituent parts just three years after formation.
1937 British Industries Fair Advert for Industrial and Marine Oil Engines. Also for buses, coaches, trolley buses, lorries, tip-wagons, rail cars etc. A.E.C. 6-cylinders 100 h.p. Marine Oil Engine, complete with reverse gear. A.E.C. 27 K.W. Oil Engine, Ships' Auxiliary Set. A.E.C. 60 K.W. Oil Engine, Generating Set, self-contained and transportable. (Engineering/Metals/Quarry, Roads and Mining/Transport Section - Stand No. D.820) 
1944 Producing diesel marine engines of either four or six cylinders and producing 47, 59 or 100 bhp.
1939-1945: A pdf copy of AEC's 'Contribution to Victory by the Associated Equipment Company Ltd.' book is available here.
1961 Manufacturers of commercial vehicle chassis, diesel engines, railcars, etc. 5,000 employees. 
1962 Taken over by Leyland Motors.
1968 Announced the first V8 diesel engine to be designed and built in Britain.
1968 Double deck bus production ceased with the last Routemaster and Regent V types built that year.
1979 Southall's stay of execution lasted another five years until 25th May, when the final Marathon goods chassis left the production line and the works was closed down.
1977 The AEC name was discontinued.
Sources of Information
- The Times 25 June 1926
- 1937 British Industries Fair Advert p598; and p329
- The Times, Saturday, Sep 04, 1948
- 1961 Dun and Bradstreet KBE