By Jonathan Davies
Some of FIFA's headline sponsors have welcomed the resignation of president Sepp Blatter.
The 79-year old yesterday (Tuesday) announced his decision to resign as FIFA president, just two days after he was re-elected.
McDonald's said it hoped that Blatter's resignation would be the first step in "gaining back trust from fans worldwide".
Visa and Coca-Cola repeated warnings that they expect swift action to reform FIFA.
Visa said: "This is a significant first step towards rebuilding public trust, but more work lies ahead," it continued.
"We repeat, however, that it is our expectation that FIFA will take swift and immediate steps towards addressing the issues within its organisation to quickly rebuild a culture with strong ethical practices that will restore the reputation of the games for fans around the world."
Coca-Cola said: "We believe this decision will help FIFA transform itself rapidly into a much-needed 21st Century structure and institution."
Budweiser, a lower level sponsor, said: "We expect today's announcement to accelerate FIFA's efforts to resolve internal issues, install positive change and adhere to the highest ethical standards and transparency."
Unconfirmed US reports suggest that Mr Blatter is being investigated by the FBI in relation to allegations of corruption at football's world governing body.
Six FIFA officials were arrested in Zurich last week on behalf of the US. Another three FIFA officials and five corporate executives were also listed on an indictment relating to alleged corruption going back more than 20 years.
Announcing his plans to resign, Blatter said his mandate "does not seem to be supported by everyone in the world".
He said: "Fifa needs profound restructuring."
The outgoing president will remain as head of the body until an extraordinary congress is called to elect a new replacement.
Mr Blatter urged the FIFA executive committee to organise the extraordinary congress as soon as possible "for the election of my successor at the earliest opportunity".
"This will need to be done in line with Fifa's statutes and we must allow enough time for the best candidates to present themselves and to campaign."
'Build a case'
The New York Times reported that US officials are hoping those already indicted will co-operate with the investigation in order to build a case around Sepp Blatter.
Officially, US authorities refused to comment on his resignation.
Separately, Swiss authorities launched a criminal investigation into the awarding of the 2018 and 2022 FIFA World Cups in Russia and Qatar. Swiss officials have however said that Mr Blatter is not part of their investigations.
Further allegations emerged on Tuesday linking FIFA secretary general Jerome Valcke to an alleged $10 million bribery payment over the World Cup in South Africa in 2010. Mr Valcke denies any wrongdoing.