Orson Welles didnt "star" in The Third Man. although he has the title role, he's only on screen for 22 minutes. I think you meant US actor Joseph Cotten stars in it. Written by Graham Greene, produced and directed by Carol Reed, with Trevor Howard, Wilfred Hyde White,
Bernard Lee. Filmed in London and Vienna. Hardly a US film, just has two US actors in it to sell the movie across the herring ...