O'Neill hails mighty Quinn

The 45-year-old former Republic of Ireland striker, who put together the Drumaville consortium which took control of the Black Cats in 2006 and served as chairman before accepting an international development role in October last year, confirmed he is to concentrate on his family and business interests after six years back on Wearside.

Quinn also persuaded his successor as chairman, American businessman Ellis Short, to buy out Drumaville and subsequently to replace him at the helm and carry on the process of firmly establishing Sunderland in the Premier League.

Manager O'Neill, who was recruited by the pair as Steve Bruce's replacement in December last year, said: "Niall has been a truly iconic figure at Sunderland, both as a player and in his time leading the club from the top.

"His vision and drive, alongside that of Ellis, played a significant part in me coming here.

"Like everyone, I couldn't be more disappointed that he has decided to step down, but of course I respect and understand his decision.

"He has been the heartbeat of the football club for so long and his legacy is immeasurable. To me, he is 'Mr Sunderland' - and always will be."

Quinn's love affair with the club began when he arrived from Manchester City, where a knee injury had severely limited him, in August 1996.

However, over the next five years or so, he made 220 appearances and scored 69 goals, most notably in partnership with Kevin Phillips, before time and a back problem caught up with him in November 2002.

Former Arsenal frontman Quinn also represented Ireland on 91 occasions and scored 21 goals, a national record until it was eclipsed by current skipper Robbie Keane.

However, he further endeared himself to Wearside when, with Sunderland having suffered an ignominious relegation from the Premier League with just 15 points at the end of the 2005-2006 season, he led Drumaville into the club and, after a brief and unsuccessful spell as manager, appointed Roy Keane to spark an ongoing revival.

Quinn, who initially indicated he would be involved for around five years, said: "Sunderland is in an incredibly fortunate position to have a hugely talented team of people leading the football club right now.

"Everything is in place for Sunderland to really make a statement, which was always my aim.

"From a football perspective, securing the services of Martin O'Neill has been an absolute highlight.

"In Martin, we have a man that understands the region, the club and the unique place it holds in the lives of its supporters, and I am confident that he will harness the immense passion that exists here and take us to new heights.

"I am now looking forward to spending more time with my family and exploring business interests away from football.

"One thing is for sure though, I'll still have that knot in my stomach before kick-off and the feeling of pure elation at the final whistle if the result has gone our way - that will never leave me."

Quinn's legacy will be Short's continued presence at the Stadium of Light as both owner and chairman, and the Texan has vowed to carry on the work the Irishman started with the club now enjoying a new resurgence under O'Neill, who guided it into the FA Cup quarter-finals at the weekend.

He said: "Niall Quinn is and always will be a Sunderland legend. His vision brought me into the club and that vision still inspires what we do.

"He has been a trusted friend and advisor to me throughout our time together at Sunderland, and whilst I'm sad about his departure, I respect his view that his 'work is done'. My job is to carry on that work."