the leo 300 was designed to meet a french requirement for a bn.5 category night bomber. it was a high-wing cantilever monoplane with a crew of five. the prototype first flew in september 1933, powered by four renault 12jb engines mounted in tandem pairs on the wings. the leo 300 was superseded by the leo 301 with more powerful engines but with the withdrawal of the requirement it was abandoned in final assembly and work on the programme was stopped.