During the Battle of France, a mixture of MB.151s and MB.152s equipped nine Groupes de Chasse; the MB.152 was the most numerous aircraft remaining in service during the final weeks prior to the signing of the Armistice of 22 June 1940. They proved to be tough aircraft, able to withstand considerable battle damage, rapidly reach high speeds during a dive, and functioned well as a gunnery platform; in air combat they were outmatched by the Messerschmitt Bf 109E on almost every count and proved slower than the twin-engined Bf 110. All Blochs units suffered heavy losses. In the week of heavy air fighting between 10 and 17 May, it was almost commonplace for a Bloch squadron to take off with eight or nine aircraft and come back with only two or three. On their side, the pilots of Bloch MB.152s claimed at least 188 enemy aircraft, for the loss of about 86 Blochs. But on the third week in May the Bloch units had been decimated and were pulled back to the Paris area to reform.