Bradley Cooper's 'career behind Renee Zellweger split'

London, March 25 (ANI): Bradley Cooper's rising career is responsible for his split from Renee Zellweger, reveals a friend of 'The Hangover' star.

The friend denied the speculation that another woman was the reason behind the couple's split.

"If I had to pick any possible mistress it would be Brad's career. He worked really hard to get into leading man status," the Daily Mail quoted the friend as saying to Us Weekly.

News that the couple had parted ways emerged last week, just days after 36-year-old Cooper paid tribute to Renee during an interview on biographical series 'Inside The Actor's Studio'.

Cooper has seen his career rise stratospherically since starring in hit comedy 'The Hangover' in 2009 after years in supporting roles in films such as 'Wedding Crashers' and 'Failure To Launch'.

Last weekend his first film as a leading man, 'Limitless', topped the US box office and took in 19 million dollars.

"Renee had to take a backseat. She travelled with him to make it work. She's accomplished a lot of her professional goals. So Renee took some time out to be a great girlfriend and see if this is what it took to make a relationship work," the friend said..

Bridget Jones star Renee even moved from her New York base to Los Angeles to be closer to Bradley.

However, the source added; "She stopped fighting. It was just not working out." (ANI)