UEFA president Michel Platini has the backing of four out of six continental soccer confederations if he runs for the FIFA presidency, a source has told Reuters.
The Frenchman, who is still undecided whether to run, was repeatedly promised support during a meeting at a lakeside hotel in Zurich on Sunday, the source said.
Sepp Blatter was re-elected for a fifth term at FIFA president in May but then announced on June 2 he would step aside.
Former UN Secretary General Kofi Annan should lead independent reforms to FIFA, campaign groups have said.
As FIFA's executive committee met to discuss reforms and a timetable for a new president to be elected, campaigners told a press conference in Zurich they had made contact with Mr Annan.
Jaimie Fuller, co-founder of New FIFA Now, said: "We are calling for Kofi Annan to come into this mess and take control of the reform process."
Tim Noonan, of international trade union body ITUC, added: "We have spoken to Kofi Annan...he has indicated that he (would be) open to receiving a proposal, the initial contact has been made."
FIFA bosses will hold their first major meeting today since the corruption crisis exploded.
President Sepp Blatter is expected to face pressure to announce an early departure from his post, after revealing he was stepping aside last month.
Blatter will hold talks with the FIFA Executive Committee in Zurich to decide a date for a special Congress to elect his successor.
The FIFA president is also expected to unveil plans to reform football's scandal-hit governing body.
FIFA president Sepp Blatter will come under pressure to agree to an early date for the election of his successor at the first meeting of the world governing body's executive committee since the corruption crisis exploded.
The meeting in Zurich on Monday will allocate the date for a special Congress to elect a new president after Blatter's announcement last month that he will step down.
That decision followed mounting pressure on FIFA following a series of arrests, including of seven FIFA officials in Zurich, following an FBI investigation and separate probes by Swiss authorities into the bidding for the 2018 and 2022 World Cups.
There were also revelations of bribes paid for votes for the 2010 World Cup in South Africa and increasing concerns from FIFA's sponsors.
Blatter has stated he wants to remain in office until the new election, to be held between December and March, but UEFA wants the 79-year-old to step down as soon as possible, and by December at the latest.
A likely date of the FIFA election looks to be in mid-January - UEFA had been pushing for December 16 but that would clash with FIFA's Club World Cup competition in Japan.
One of seven top officials of football's world governing body Fifa has pleaded not guilty to corruption charges in a US federal court.Read the full story ›
Head of Bolivia's football federation, Carlos Chavez, was arrested on Friday on charges of corruption in the management of finances.Read the full story ›
A Fifa official arrested in Zurich as part of the corruption scandal has been extradited to the United States, Switzerland's Federal Office of Justice has confirmed.
The man in question is reported to be Jeffrey Webb, the vice president of Fifa and CONCACAF.
A statement from Swiss officials said the Fifa official - one of seven arrested in dawn raids on May 27 - "was handed over to a three-man U.S police escort in Zurich who accompanied him on the flight to New York."
Swiss officials declined to release the man's name when contacted by Press Association Sport but confirmed he had agreed to be extradited last week.
It is understood that Webb, who arrived in the U.S on Wednesday, was the only arrested Fifa official not fighting extradition.
Webb, 50, is accused of accepting bribes worth millions of dollars, and he has already been suspended from football duty by Fifa's ethics committee. He is expected to face the charges in a New York court.
The first of seven Fifa officials held in Switzerland on corruption charges has been extradited to the United States, the Swiss Federal Office of Justice has said.
The official, who has not been named, was handed over to a three-man US police team in Zurich on Wednesday, the justice office said.
A source told Reuters last week that Jeffrey Webb, a former Fifa vice president, had agreed to be extradited.
But the justice office did not confirm a name, saying in a brief statement: "The first of the seven Fifa officials being held in custody in Switzerland was extradited to the US on 15 July.
"He was handed over to a three-man US police escort in Zurich who accompanied him on the flight to New York."
Former senior FIFA official Jeffrey Webb has agreed to be extradited to the US, a source has told Reuters.
Webb is one of seven current and former officials of soccer's world governing body arrested in Switzerland during a corruption probe.
Webb, a former FIFA vice-president and ex-president of CONCACAF, is expected to be sent to the US under police escort within the next 10 days.
An unnamed FIFA official arrested in the ongoing corruption probe has agreed to be extradited to the United States.
The man, one of seven FIFA officials detained in Switzerland, will be sent to the US under police escort within the next 10 days, according to the Federal Office of Justice