Rolls-Royce Limited increase its own production rates. By the late 1920s, aero engines made up most of Rolls-Royce's business. Henry Royce's last design was the Merlin aero engine, which was first flown in prototype form in 1935, although he had died in 1933. This was developed from the R engine, which had powered a record-breaking Supermarine S.6B seaplane to almost in the 1931 Schneider Trophy. The Merlin was a powerful supercharged V12 engine and was fitted into many World War II aircraft: the British Hawker Hurricane, Supermarine Spitfire, de Havilland Mosquito (twin-engine), Avro Lancaster (four-engine) (a development of the Avro Manchester with
Rolls-Royce Holdings the joint venture company, which also now incorporates Rolls-Royce's existing Bergen engine business, is listed on the Frankfurt Stock Exchange. Following the acquisition of Goodrich by United Technologies Corporation in July 2012, Rolls-Royce announced it would purchase Goodrich's 50% share of Aero Engine Controls to become wholly owned by Rolls-Royce Plc and a part of the Rolls-Royce Group. In May 2014, Rolls-Royce sold its energy gas turbine and compressor business to Siemens for £785 million. In 1990, BMW and Rolls-Royce established the BMW Rolls-Royce joint venture to produce the BR700 range of engines for regional and corporate jets, including the