Sepp Blatter has rocked the world of soccer by unexpectedly quitting as FIFA president in the face of a corruption investigation that has plunged the game's governing body into the worst crisis in its history.
Blatter (79) announced his decision at a hastily-arranged news conference in Zurich, six days after the FBI raided a hotel in the city and arrested several FIFA officials and only four days after he was re-elected to a fifth term as president.
Blatter said an election to choose a new president for the deeply-troubled organisation would be held as soon as possible.
A FIFA official said that could happen any time from December this year to March of next year.
"FIFA needs profound restructuring," said Blatter, a Swiss national who has been a dominating presence at FIFA for decades.
"I have been reflecting deeply about my presidency and about the 40 years in which my life has been inextricably bound to FIFA and the great sport of football. I cherish FIFA more than anything and I want to do only what is best for FIFA and for football.
"I felt compelled to stand for re-election, as I believed that this was the best thing for the organisation. That election is over but FIFA's challenges are not. FIFA needs a profound overhaul.
"It is my deep care for FIFA and its interests, which I hold very dear, that has led me to take this decision.
"While I have a mandate from the membership of FIFA, I do not feel that I have a mandate from the entire world of football - the fans, the players, the clubs, the people who live, breathe and love football as much as we all do at FIFA.
"Therefore, I have decided to lay down my mandate at an extraordinary elective congress. I will continue to exercise my functions as FIFA president until that election."
Blatter's decision was immediately welcomed by his most prominent critics.
European football federation chief Michel Platini, a French former international soccer star, said: "It was a difficult decision, a brave decision, and the right decision."
Greg Dyke, chairman of the English Football Association, said it was "good news for world football".
FIFA, which Blatter had ruled since 1998, was left reeling by the announcement of a US investigation into alleged widespread financial wrong- doing stretching back more than two decades.
Swiss authorities also mounted their own criminal probe into the awarding of the 2018 and 2022 World Cups to Russia and Qatar respectively.
The US Justice Department, the FBI and the US Attorney's office in Brooklyn had no immediate comment.
The office of the Swiss Attorney General, which is investigating alleged criminal mismanagement and money laundering at FIFA, said Blatter's resignation would have no effect on its proceedings.
It said Blatter himself was not subject to investigation.
While Blatter was not mentioned in either the US or Swiss investigations, there had been widespread calls for him to quit, mostly from western nations. Some major sponsors also expressed misgivings about the impact of the scandal.
"This is an important step but a lot of work remains. We now expect a long process of change that is needed to restore trust and set up a solid system of good governance at FIFA," said the European Commission's spokeswoman for sport, Nathalie Vandystadt.
Blatter had initially tried to bat away the furore, relying on his extensive network of friends to hold on to power at FIFA.
Football associations in Africa and Asia had stood by him despite the scandal, saying they welcomed the FIFA funds he channelled to them for the development of the game in impoverished parts of the world.
The investigation, however, closed in on Blatter yesterday, when FIFA was forced to deny that his right-hand man, Jerome Valcke, was implicated in a $10m (€9m) payment that lies at the heart of the US case.
Valcke, who has been secretary general since 2007 and is seen as one of the most powerful men in world sport, had no role in the payments, which were authorised by the chairman of FIFA's finance committee, FIFA said in a statement.
The chairman of the committee at the time of the payments was Argentina's Julio Grondona, who died last year.
"Neither the secretary general Jerome Valcke nor any other member of FIFA's senior management were involved in the initiation, approval and implementation of the above project," FIFA said.
However, a person familiar with the matter said on Monday that US prosecutors believe Valcke made the $10m bank transactions which are central to a US bribery investigation against soccer's governing body.
Valcke is described in an indictment filed in federal court in Brooklyn, New York, as an unidentified "high-ranking FIFA official" who in 2008 transferred the sum to another FIFA official, Jack Warner.
Blatter became FIFA secretary general in 1981 and president 17 years later.
He survived a series of scandals including widespread accusations that Qatar bought the right to stage the 2022 World Cup in a country with little football history and where summer temperatures regularly top 40C. Qatar has always denied any wrongdoing.
Despite calls for Blatter's resignation after what was described as the worst day in FIFA's history last Wednesday, when seven serving officials were arrested on bribery charges two days before the body's 2015 election congress, he told delegates then: "Football needs a strong and experienced leader. One that knows all the ins and outs and can work with our partners."
Overcoming opposition from European soccer's governing body, UEFA, which threatened at one point to boycott the congress, he was elected for another four years.
His fifth term lasted only four days.