Fifa sponsors, including Visa, Coca-Cola and McDonald's, have welcomed Sepp Blatter's decision to resign as president of football's world governing body.
Mr Blatter's decision to step down comes amid a corruption scandal.
However, both Visa and Coca-Cola repeated warnings that they expected a swift overhaul at Fifa.
And McDonald's said it hoped this would be the first step towards "gaining back trust from fans worldwide".
Last week, Fifa was hit by the arrests of top officials on charges of racketeering, wire fraud and money laundering as part of a US prosecution that also indicted 14 people.
Mr Blatter was subsequently re-elected, but on Tuesday resigned, saying that his mandate "did not appear to be supported by everybody".
Visa said it was encouraged "by the recognition by Fifa that extensive and fundamental reform is needed as reflected by the announcement that President Blatter is resigning".
"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."
'Act with urgency'
That sentiment was echoed by Coca-Cola, which described the move as "a positive step", but added that it expected Fifa to "act with urgency" and "win back the trust of all who love the sport of football".
"We believe this decision will help Fifa transform itself rapidly into a much-needed 21st Century structure and institution," Coca-Cola said.
Other sponsors, Budweiser, Adidas and McDonald's, also issued broadly positive statements.
"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," said Budweiser.
Adidas said the news marked "a step in the right direction on Fifa's path to establish and follow transparent compliance standards in everything they do."
For its part, McDonald's said it was "hopeful" that the changes being implemented would lead to Fifa being reformed and "gaining back trust from fans worldwide".
Hyundai said the resignation was a "positive first step in creating a governance structure that ensures the highest ethical standards for the sport."
Who are Fifa's five top tier partners and two World Cup sponsors?
Adidas - the German sportswear firm has been supplying the official match ball for all Fifa World Cup tournament matches since 1970. Also involved in all other Fifa events, such as the Confederations Cup Brazil 2013, and the Fifa U-20 World Cups for women and men.
Coca-Cola - the US soft drinks firm is one of the longest-standing corporate partners of Fifa, with a formal association since 1974 and an official sponsorship of the Fifa World Cup that began in 1978. Coca-Cola has had stadium advertising at every Fifa World Cup since 1950.
Gazprom - the Russian energy giant signed up with Fifa in 2013 as a partner for all competitions in the period of 2015 to 2018, including the 2018 Fifa World Cup, which is due to take place in Russia for the first time. (The firm is also an official partner of the Uefa Champions League 2012 to 2015).
Hyundai/Kia - the South Korean carmaker began its Fifa alliance in 1999, in a deal to sponsor 13 Fifa competitions including the 2002 World Cup, an agreement extended to the 2006 event. It again backed the 2010 World Cup and is now the official Automotive Partner of Fifa until 2022.
Visa - the credit card company became a top-tier Fifa partner in 2007, taking over from rivals MasterCard in controversial circumstances, and recently extended its relationship until 2022. It is a sponsor of five Fifa events this year, including the Women's World Cup in Canada.
Budweiser - the US beverage has been a World Cup sponsor since the 1986 event in Mexico, and is the Official Beer of the tournament, with its product on sale in all stadia at the finals, and it also sponsors the Man of the Match award at each game.
McDonald's - the American fast food chain has been a sponsor since the 1994 World Cup in the US. Its products are available at all matches in the finals tournament, and it also sponsors the World Cup Player Escort programme, in which children accompany the teams onto the pitch.