 Based on the M 4 chassis in 1950 a prototype was finished of a heavy tank destroyer in the form of a 120 mm self-propelled gun, the "Canon Automoteur AMX 50 Foch", named after Marshal Ferdinand Foch.It was intended to give long range fire support to the medium AMX 50 "100 mm".After the tank version was planned to be armed with a 120 mm gun, the Foch project was abandoned.