Michel Zen-Ruffinen's role as general secretary of world soccer's governing body FIFA officially came to a close on Thursday.

Zen-Ruffinen, 43, had agreed with FIFA's executive committee in May to step down after his relationship with his chief Sepp Blatter collapsed in the run-up to the world body's presidential election in Seoul.

He will be temporarily replaced by Urs Linzi, who has been appointed as acting general secretary, before a full-time replacement is announced at FIFA's executive committee on September 23-24.

"FIFA has successfully negotiated all the challenges it has faced in recent weeks. The next task is to begin preparations for the 2003-2006 World Cup cycle by introducing appropriate internal structures," Blatter said.

Zen-Ruffinen, whom Blatter appointed in 1998 and once described as being "like a son to me", issued a damning report on May 3 alleging Blatter may have been guilty of criminal charges for the way he ran FIFA.

Eleven FIFA executive committee members instigated legal proceedings in a Swiss court alleging misuse of funds on the basis of Zen-Ruffinen's report.

But Blatter regained the upper hand and ended months of in-fighting by winning a second four-year term by a landslide in the election on the eve of the World Cup finals in South Korea and Japan.

Blatter tightened his grip on FIFA, his rivals halted the legal action against him and his estranged general secretary agreed to step down.

Zen-Ruffinen remained in charge of the month-long World Cup finals, but agreed to leave his post four days after the June 30 final in Yokohama.

Speaking in Tokyo last week, Zen-Ruffinen said FIFA was entering one of the most difficult periods in its history while soccer was facing an increasingly uncertain financial future and called for unity.

"The fact I am leaving makes no real difference. The people running FIFA in the future will have to be united and face the challenges ahead of them," he said.

"When you run world football you need to have serenity, you need people who are committed to the management but I think FIFA is entering the most difficult period it has ever had.

"My report focused on what I believed was the mis-management of the finances and I have not changed my view at all," he said.

Zen-Ruffinen said he felt no personal animosity towards Blatter.