High Quality Content by WIKIPEDIA articles! The AEC Regent III (also known as Regent 3 or Regent Mark III) was a type of double-decker bus chassis manufactured by AEC. It was mainly built for operation outside London and the overseas. It could be fitted with AEC's 9.6-litre diesel engine (except a minority with 7.7-litre ones), 'Wilson' preselective epicyclic gearbox (except for a minority with crash gearboxes. A synchromesh option also became available in the early 1950s) and air pressure operated brakes (except a minority with vacuum brakes). The Regent III was available with bodies from a number of manufacturers including Park Royal, Metro Cammell Weymann and Charles H. Roe. AEC Regent III was superseded by the AEC Regent V, not the AEC Regent IV underfloor-engined double decker which existed as a one-off prototype only. The last Regent III's were supplied to Reading Corporation in 1956.