NIALL Quinn has tipped Roy Keane to return to the Barclays Premier League one day after reluctantly accepting he had taken Sunderland as far as he could.

The 37-year-old this morning resigned from his post at the Stadium of Light after 27 eventful months as his former Republic of Ireland team-mate lost the battle to persuade him to stay.

Keane's position had become the subject of intense speculation over the last few weeks, but his personal misgivings grew in the wake of Saturday's 4-1 home defeat by Bolton, which saw his side slip into the relegation zone.

After days of agonising over the decision with Quinn pleading with him to hold firm, the Irishman fell on his sword to end the dream he inspired when he agreed to launch his managerial career on Wearside in August 2006.

His chairman, despite his obvious disappointment, vowed the mission to revive the club would continue, but also voiced the opinion Keane would be back in the Premier League before long.

He said: "The Premier League from day one, Roy has been all over it. He has been a massive figure.

"That just doesn't end. In his absence, he still will be and the time will pop along and he will have gained from this experience and something will come for him, I have no doubt.

"He will get a bit of time to himself now and I am sure he will recharge and get going again, and I am sure we all know the Premier League hasn't seen the last of him and he has got great things to come."

Sunderland eventually confirmed the news that had been circulating for several hours at around 12.35pm today, shortly before Keane was due to conduct his regular pre-match press conference ahead of Saturday's trip to former club Manchester United.

He did not appear, but he issued a short statement, which read: "I would like to thank my staff, players, Niall Quinn and, in particular, the fans, for their support during my time at Sunderland, and would like to wish the club every success in the future."

It was left to Quinn to face the media as he explained Keane's reasons for resigning.

He said: "Roy, as he says himself, is his harshest critic. He just felt he had completed his journey here, and he just felt he didn't want to get it unstuck any further and find ourselves in deeper, darker territory.

"That's the measure of the guy. It's funny, in situations like this, I am sure nine times out of ten, the chairman is saying how the manager was trying to keep his job.

"It was the other way round. We spent three days trying very hard to see if we could find a solution that way.

"But when push came to shove and different things are thrown together, I suppose in the end, it was such an amicable agreement.

"It's a disappointing day in many respects, but of course, we fully respect his decision.

"And of course, once he made his decision, I said to him, I know you too well, Roy, to try to overturn it now once he went over that line."

Coach Ricky Sbragia, assisted by Neil Bailey and former United midfielder Dwight Yorke, will take charge in the interim as Quinn launches the search for a replacement.

The chairman was obviously disappointed, but remarkably upbeat about the future after seeing his masterplan unravel.

He said: "We have a good team. Roy Keane hasn't been sacked because we have a bad team, he has resigned because we have a good team he feels he can't bring any further.

"There is a big difference there."

It was Quinn who put together the Drumaville consortium that bought out predecessor Bob Murray and then pulled off a major coup when they persuaded Keane to take the plunge into management.

Promotion from the Coca-Cola Championship at the first attempt was rich reward for the club's ambition, and the financial investment that followed it - Keane spent upwards of £70m on strengthening his squad - was a sign of their continuing intent.

However, a run of six defeats in seven games led Keane to question himself as his comments about his own future became increasingly ambiguous with his three-year contract running down and no new deal agreed, and American investor Ellis Short increasing his influence.

That combination of factors meant there was only ever likely to be one outcome.

Former Newcastle boss Sam Allardyce was swiftly installed at the top of a list of possible successors, which also includes Alan Curbishley, although Quinn insists that has barely crossed his mind yet.

He said: "Probably, in fairness, it will start once you guys go home and the dust settles down.

"Myself and the other board members will probably revert back to the stadium and have our first thoughts on that."