Sir Michael Caine wants to star in a sequel of 'Harry Brown'.

The 78-year-old actor - who appeared as the titular character in the action drama film - has been asked if he would appear in a second version of the movie, but he is unsure whether it will happen or not because of his busy schedule.

Speaking at the UK premiere of 'Cars 2' in London's Whitehall Gardens on Sunday (17.07.11), Michael - who is currently filming The Dark Knight Rises - told BANG Showbiz: "They were thinking of doing a sequel for 'Harry Brown' and they asked if I'd do it and of course I said I would.

"But I'm not available until the middle of next year so you never know if it'll get made or not."

Michael's most recent films have seen him lending his voice to roles in 'Gnomeo and Juliet' and 'Cars 2' - which sees him star as spy car Finn McMissile - and the British star admits voiceovers are "easy" because you don't have to "look your best" in the studio.

He explained: "It's not very difficult doing voiceovers - they're easy. You don't have to get made up, you don't have to look your best, you don't have to do anything apart from sit in a room.

"If you have a great director like John Lasseter, who wrote the thing, then he knows exactly what's going on and he can tell you every little nuance if it goes wrong."

Michael has previously revealed he did 'Cars 2' for his three grandchildren, because they are too young to watch gangster film 'Harry Brown'.

She said: "When they ask what their granddad does, they can't see him in anything.

"You don't want to say 'Harry Brown'. It's not family viewing. When they offered me the chance to play the part of a car, I was very interested."