Alex Ferguson, Britain's longest-serving and most successful football manager, will retire at the end of the season after more than 26 years spent decorating Manchester United's trophy room with silverware.



The 71-year-old Scot ended intense speculation about his future at Old Trafford by confirming he would step aside after champions United's last game of the season at West Bromwich Albion on May 19 - his 1500th in charge.



His decision brings the curtain down on a glittering era for the country's best-supported club which included 13 English league titles, two European Cups, five FA Cups and four League Cups as well as the FIFA Club World Cup.



Everton boss David Moyes, a Glaswegian like Ferguson, is strongly tipped to be United's next manager with one British bookmaker offering odds of 20-1 ON.



Former Chelsea coach Jose Mourinho is also in the running to fill the void left by the retiring Scot and is priced at 10-1.



United chief executive David Gill told the club's in-house television channel MUTV they would move "relatively quickly" in naming a successor.



Ferguson arrived in Manchester in 1986 after Ron Atkinson was sacked and, after a difficult start, began building an empire that shows no sign of crumbling with the club recapturing the English title from Manchester City this season.



"The decision to retire is one that I have thought a great deal about and one that I have not taken lightly. It is the right time," Ferguson, who has won nearly 900 of his 1,498 matches in charge, said on United's website (www.manutd.com).



United said Ferguson, who is to undergo hip surgery during the off-season, would remain at the club as a director.



"It was important to me to leave an organisation in the strongest possible shape and I believe I have done so," added Ferguson who had announced he would retire after the 2001-02 season before changing his mind.



"Going forward, I am delighted to take on the roles of both director and ambassador for the club," he said.



"With these activities, along with my many other interests, I am looking forward to the future."



Ferguson, who in 2010 surpassed Matt Busby's as the longest-serving manager in United's history, had not hinted at retirement in his programme notes for Sunday's game against Chelsea, suggesting he was keen to continue.



Bobby Charlton, a member of Busby's side that won the European Cup in 1968 and still a director, said United's dominance of the English game was solely down to Ferguson.



"I am a director but I hardly do anything because we are winning all the time and it is all down to Alex Ferguson," Charlton said at a stamps launch at Wembley on Wednesday.



"He is such a fantastic manager. Everything he has done has been fantastic."



'MASSIVE SHOCK'



The suddenness of his decision left some who served under him in a state of disbelief.



"I'm shocked, it's a bombshell," said former United goalkeeper Peter Schmeichel, who was part of the 1998-99 team who won the Premier League, Champions League and FA Cup.



"I'm disappointed and very, very sad. He had always said he would retire when something in his life wasn't right, and it must be something we don't know about."



Former Manchester United midfielder and current Blackpool boss Paul Ince told Sky Sports: "I'm totally shocked. What he's done is unbelievable. You'll never see anyone of his kind again.



"Two weeks ago he was talking about staying on for another two years, so it's a massive, massive shock."



Bryan Robson, Ferguson's first captain, added: "He will always be the boss to me, you don't think of him as Sir Alex it has always been the boss."



FIFA president Sepp Blatter reacted to the news by describing Ferguson as one of "the greats".



"Will his longevity at the top ever be repeated?" the Swiss said on his Twitter feed.



Ferguson's long service in English football's top tier, where managers are hired and fired on a whim by success-hungry owners, is testament to his enduring passion for the game and his ability to cope with the demands of dealing with the brash young millionaires who populate the changing rooms.



He has seen off seven Liverpool managers since his arrival and 15 at Chelsea and only Arsene Wenger, who has been at Arsenal since 1996, and Moyes, at Everton for 11 years, are in Ferguson's league when it comes to staying power.



Even after his 70th birthday he remains as animated as ever, celebrating goals with the same boyish enthusiasm he brought from Aberdeen with whom he won the UEFA Cup Winners' Cup in 1983.



Chastened by losing the title to Manchester City, whom he once famously dubbed "noisy neighbours", in the dying seconds of last season, Ferguson, as he has always managed to do, raised the bar again, signing Arsenal's Robin van Persie.



In what proved to be Ferguson's transfer masterstroke, the Dutchman's 25 league goals helped United to a record 20th league title, two more than the 18 won by Liverpool whom Ferguson vowed to "knock off their perch" when he arrived in 1986.



Chief executive Gill, a loyal ally of Ferguson's for the past 16 years, said Ferguson's legacy would live on, whoever is named as his successor and that the outgoing manager would have a say on the new appointment.



"The qualities (of the next manager) are the ones that have been inherent within Manchester United for many years," he told MUTV.



"If you look at what has happened with the two most successful eras - Sir Matt Busby and Sir Alex - they are managers who got involved in the whole aspect of the club, whether it be from the youth team up to the first team.



"Clearly he has to have the requisite football experience, both in terms of domestic and European experience, so I think it's a small pool but we'll move forward."



Former chairman Martin Edwards, the man responsible for hiring Ferguson, said the club owed a debt of gratitude.



"The success in 1990 revived everything. It saved us really," he said. "He's a workaholic. He's got such a great knowledge of football. I don't think you'll ever see anyone managing Man United for 27 years again."



Ferguson, a horse-racing enthusiast and wine connoisseur, was not an overnight success, however, experiencing some difficult years before landing the FA Cup in 1990 and the Cup Winners' Cup the year after.



Ending United's 25-year wait for the English title in 1992-93 proved to be the catalyst for two decades of domination despite the challenges of Arsenal, then Chelsea and more recently Manchester City.



Famous for his so-called "hair dryer" outbursts of rage at high-profile players, his manic gum-chewing and unbridled joy at every goal scored, Ferguson established an attacking style fitting for the Theatre of Dreams.



His faith in young players launched the careers of David Beckham, Paul Scholes, Gary Neville and Ryan Giggs while his signings of players such as Eric Cantona, Rio Ferdinand, Cristiano Ronaldo and Wayne Rooney made sure that United, for the most part, remained ahead of their rivals.



Since the advent of the Premier League, United have never once finished outside the top three.



Off the field, Ferguson, who received a knighthood in 1999, proved himself the perfect ambassador and diplomat as the club controversially passed into the ownership of the American Glazer family in 2005.



"Alex has proven time and time again what a fantastic manager he is but he's also a wonderful person," co-chairman Joel Glazer, son of owner Malcolm, said in the club statement.