The new "Falco" II was equal to the Macchi MC.202, but the Macchi fighter, having first call on production for the Alfa Romeo R.A.1000RC.41-1a (the license built DB 601) was still produced in greater numbers. The Re.2001 was then delayed because the Regia Aeronautica insisted on the fuel tanks being placed inside the wings, which required a substantial redesign of the wing structure. The first order, amounting to 300 machines, was cut back with only 252 produced. This number included 100 Re.2001 "Serie I", "Serie II" and "Serie III" with armament variations, the Reggiane "Serie IV" fighter-bomber and 150 Re.2001 CN "Caccia Notturna", night fighter.