The club released a statement on Thursday afternoon saying O'Leary had left by mutual consent.

O'Leary signed Ferdinand from West Ham for �18m last year and there has been strong speculation that the England international will be sold to ease the club's financial worries.

"It's a massive shock, and I'm disappointed to see this happen," Ferdinand said.

"He's been with the club through good and bad. He paid a lot of money to sign me and he's been brilliant for me, first-class."

Transfer deficit

Meanwhile George Graham believes his prot�g� David O'Leary will make a return to football as a better manager despite being sacked.

The former Leeds boss manager brought in O'Leary as his assistant at Elland Road in 1996 and when Graham left for Tottenham two years later, the Irishman took over.

"I would say to him, as a young up-and-coming manager, he has had four outstanding years at Leeds and not to let this kill any confidence he has in the management profession," said Graham.

"I think he is going to be a top manager and I think he will be back better than ever.

"If you consider he was only under my wing for a couple of years, he took over the team and every year he finished in the top six and qualified for Europe."

Graham also defended O'Leary over criticism of his transfer dealings for Leeds, in which he ran up a deficit in excess of �67m.