Hollywood star George Clooney has played down his friendship with his OCEAN'S TWELVE co-star Brad Pitt, insisting "he's one of my showbiz friends".

While Clooney admits they have a great working relationship and enjoy spending time together, they're not as close as the media suggests.

The actor says, "It's not like we call each other every day. We're 'showbiz friends', we're not like, 'friends, friends'.

"It's not like we go backpacking together."

Clooney has recently laughed off reports Pitt would marry Angelina Jolie at his home on Lake Como, Italy, insisting that while they're not that close, the glamorous couple are welcome to visit anytime they want.

He adds, "They're in Europe at the moment. All the tabloids had that he was coming to my house to get my married.

"It's hard. I think if you look at a magazine in the past three months, there's not one that doesn't have them on the front cover.