FIFA ruled yesterday that clubs are obliged to release players aged 23 or under for the Beijing Olympics, clearing the way for Lionel Messi to play for Argentina despite opposition from FC Barcelona.

Slim Aloulou, a Tunisian judge on FIFA's player status committee, said the release of under-23 players was "mandatory for all clubs".

"Taking part in the Olympic Games is a unique opportunity for all athletes of any sporting discipline," FIFA said in a statement. "It would not be justifiable to prevent any player younger than 23 from participating in such an event if his representative team had qualified."

Barcelona said in a statement it would appeal the decision.

"FC Barcelona will shortly present before the CAS, or Court of Arbitration for Sport, an appeal against this decision in which it will request the ruling be rescinded and that proceedings be completed with the maximum speed possible," the club said.

Barcelona president Joan Laporta said he would be meeting with Messi to discuss the matter.