From the Bloch MB.150 prototype, production was started on the MB.151 and MB.152.
The initial production model was the MB.151, but it was found to be under-powered. The MB.152 was developed in parallel with a higher powered engine and more armament, and once engine overheating problems had been overcome production was switched to the MB.152 model after 144 MB.151's had been built.
The MB.151's initially suffered airframe vibrations, and were relegated to training duties before the outbreak of WW2. Before the Fall of France the MB.151's were being slowly released to squadron service to act as trainers as the MB.152's were coming from production to become the definitive fighter version.
Some MB.151's remained in service with the Vichy French Air Force, before its disbanding in December 1942.
Greece was the only export customer for the MB.151, urgently needing combat aircraft. Out of an order for 25, only 9 had been delivered before the French capitulated. The Greek aircraft were still entering service when Greece was attacked, and although scoring several kills, the final Greek MB.151 was shot down on 19 April 1941.
Like many other captured French types, MB.151's made their way to Germany where they were used for evaluation.