Formed by changing name of SNCASO 1 September 1956. Main product SO.4050 Vautour; still working on SO.1221 Djinn and SO.9050 Trident; made wings and rear fuselage for Mystère II and IVA, and Martin-Baker seats under licence. Acted as agent and parent-firm for French Vertol H-21C, but did not take up licence option. Amalgamated with Sud-Est to form Sud-Aviation 1 March 1957.