World soccer's governing body FIFA has reminded clubs that they must release any players aged under 23 who are called up by their countries for next month's Olympic Games in Beijing.

"The release of players younger than 23 has always been mandatory for all clubs," FIFA said in a statement on Thursday. "For Beijing 2008 the same principle shall apply."

A FIFA spokesman told Reuters that the clarification had been sent out after several European clubs questioned the need to release players at a time when their own domestic league seasons will be getting underway.

Under rules agreed between the International Olympic Committee (IOC) and FIFA, the Olympic football competition is primarily an under-23 event although teams are also allowed to select up to three older players.

Clubs are not obliged to release the overage players but FIFA president Sepp Blatter, an IOC member, has repeatedly urged them to do so out of respect "for the Olympic spirit."

Brazil, who have never won the Olympic title, named an impressive squad for the Games on Tuesday including Barcelona forward Ronaldinho and Real Madrid striker Robinho as two of their overage selections.

Barcelona have already said they will not release Ronaldinho despite having told the player that he no longer features in their plans for next season.

Other Brazil squad members under the age limit included Liverpool midfielder Lucas, Manchester United midfielder Anderson, Werder Bremen's Diego, AC Milan striker Alexandre Pato and Manchester City's new signing Jo.

Sixteen countries are taking part in the Olympic soccer tournament, including four of FIFA's top 10 ranked teams: Argentina, Brazil, Italy and Netherlands.

The soccer programme runs from August 6, two days before the Games' official opening, until August 23.

(Reuters via China Daily July 11, 2008)