Mark Ruffalo has said Adam Levine and CeeLo Green needed no tips from him on acting in new movie Begin Again.

Maroon 5 frontman Adam makes his acting debut in the romcom starring Keira Knightley as a songwriter who catches the eye of a washed-up record exec, played by Mark. Adam plays Keira's character's ex-boyfriend and CeeLo plays a hip-hop star called Troublegum.

Mark laughed: "No, they didn't need any advice, they did pretty darn good on their own.

"Adam - it's his acting debut and I have to say he's a heck of a lot better than I was in my first film.

"And CeeLo also - they're naturals. I don't know if it's from being on stage in giant auditoriums or what, but they're both incredibly gifted actors."

The 46-year-old actor, who plays The Incredible Hulk in The Avengers and Iron Man films, also revealed he is still waiting to hear from Marvel if he'll get his own stand alone Hulk movie.

Mark said: "I don't know, they sort of went from a no to a maybe in the last three or four years, but there's still no definitive decision on whether they're going to do that now."

He added: "Avengers 2 is going really well. It's bigger, it's got a bigger scope, it's more sprawling, it's epic, and it's nice to be back with all my fellow Avengers."