Data from Howson
MS.340
Prototype with 89.5 kW (120 hp) de Havilland Gipsy III inverted in-line engine.

MS.341
Prototype re-engined with an 89.5 kW (120 hp) Renault 4Pdi inverted in-line.

MS.341/2
89.5 kW (120 hp) Renault 4Pdi inverted in-line engine.

MS.341/3
104 kW (140 hp) Renault 4Pei inverted in-line engine.

MS.342
97 kW (130 hp) de Havilland Gipsy Major inverted in-line engine.

MS.342/2
MS.342 with enclosed cockpits.
One only.

MS.343
130.5 kW (175 hp) Salmson 9Nd radial engine.

MS.343/2
100 kW (135 hp) Salmson 9Nc radial engine.

MS.345
Modifications to wings, undercarriage and empennage.
100 kW (140 hp) Renault 4Pei inverted in-line engine.
Data from Howson
MS.340
Prototype with 89.5 kW (120 hp) de Havilland Gipsy III inverted in-line engine.
MS.341
Prototype re-engined with an 89.5 kW (120 hp) Renault 4Pdi inverted in-line.
MS.341/2
89.5 kW (120 hp) Renault 4Pdi inverted in-line engine.
MS.341/3
104 kW (140 hp) Renault 4Pei inverted in-line engine.
MS.342
97 kW (130 hp) de Havilland Gipsy Major inverted in-line engine.
MS.342/2
MS.342 with enclosed cockpits. One only.
MS.343
130.5 kW (175 hp) Salmson 9Nd radial engine.
MS.343/2
100 kW (135 hp) Salmson 9Nc radial engine.
MS.345
Modifications to wings, undercarriage and empennage. 100 kW (140 hp) Renault 4Pei inverted in-line engine.
Morane-Saulnier MS.341