Etablissments LeO of Levallois-Perret was founded by
Henri Olivier and Fernand Liore. Established as agricultural
and industrial engineers in 1906, entered aviation
1908. Liore worked with Witzig-Liore-Dutheuil in 1912.
Firm built Morane-Saulnier types before and during First
World War, producing over 2,000. From 1916 built
1-Strutter. In 1921 started up airline Aeronavale
(Societe Maritime de Transport Aeriens), and in 1922 began
design and construction of civil and military flying-boats
and bombers. An airliner derived from the 1924 bomber
served Air Union. Four engined flying-boats developed up
to Second World War. Cierva autogiros built under license.
LeO 451, built 1939-1940, was best French bomber of
period and used for research after war. The Argenteuil factory
became part of SNCASE and the Rochefort plant part
of SNCASO in 1936.