read Robert Evan's book "The Kid Stays in the Picture", he tells the true inside story of how he got Pacino out of the contract from MGM.

Pacino was supposed to do a movie with MGM "the gang who couldnt shoot straight", Bob Evans called Jim Aubrey (MGM president) and asked him to release Pacino from his contract. When Jim Aburey refused, Bob Evans called Sidney Korshak, the famed mob lawyer and secret owner of the Riviera at that time to settle the disagreement. Korshak called Kirk Kirkorian, owner of the MGM (who was building the MGM grand hotel & casino at that time) and threatened him with some union shit. Kirkorian agreed, Pacino was released from the contract, De Niro (who was supposed to play pauli gatto) was traded to MGM to star in the gang who couldnt shoot straight.