Brad Pitt says George Clooney won't be best man at his wedding but might help people find their seats.

The two actors starred alongside each another in several films and have a longstanding history of friendship.

However, Brad isn't sure how involved George will be when he marries Angelina Jolie.

"George doesn't like institutions," the actor laughed to British newspaper The Independent.

"Perhaps he could show people to their seats."

The Hollywood couple announced their engagement earlier this year and are already proud parents to six children Maddox, Pax, Zahara, Shiloh, Knox and Vivienne.

Speculation over wedding dates and venues has been rife, with the latest rumours pointing to Richmond in London, where the family have been based for the last few months.

"We've had an amazing summer in London," Brad enthused.

"Even with the rain. We've had the Euro Cup, the Olympics, the Paralympics, Andy Murray at Wimbledon, it's been an incredible experience. Britain's certainly been good to us."

The couple famously announced they won't wed until gay marriage is permitted in the US.

Although Brad's mother, Jane, recently declared she doesn't back same sex unions, he remains positive the law will change.

"The next generation, they get it. It will happen," he stated.