Brad Pitt has reportedly bought fiance Angelina Jolie one of the world's most expensive watches.

The 250,000 timepiece is a Patek Philippe Minute Repeater which normally sees customers waiting two years to get their hands on one.

But Britain's The Sun newspaper reports that the Fight Club star bought the expensive item as an early wedding present.

The gold watch has a mother of pearl dial and takes two months to put together with each one being checked over by a member of the Stern family, who own the company, at their headquarters in Geneva, Switzerland.

"Brad decided to buy one of the most amazing watches after meeting the Stern family at a watch fair in Basel," a source told the publication.

"He wanted to buy Ange a unique gift that very few people own which is like a piece of art and the highly sophisticated watch is just that.

"It chimes sounds based on Big Ben and is constructed by hand. He went to Geneva to pick it up and it's believed he'll present it to Ange as a pre-wedding gift."

The couple got engaged in April are parents to six children.