Le grand bluff (1957)

A penniless adventurer, Eddie Morgan survives on his wits and good humor. He's a bluffer. To help the owner of an oil field, he launches a vast investment campaign, with the help of a few friends, to benefit the French people. A rival group, led by Serge Colonna and Dominique Ardan, tried to buy the land from him, because according to an expert, there was no oil to exploit. But the expert had lied, and Colonna had just signed the purchase contract. Eddie, with the help of Dominique, whom he has seduced in the meantime, snatches the famous paper from Colonna's hands. The oil can flow.