The G14's involvement in the case follows an attempt by Belgian first division club Charleroi to sue FIFA after one of their midfielders, Abdelmajid Oulmers, was injured while playing for his home country of Morocco against Burkina Faso on November 2004.

Charleroi say the loss of the player hindered their chances of success in the Belgian league and cup. FIFA says there is no link between the injury of Oulmers and where Charleroi finished in the league last season, fifth.

"We are in court today because FIFA were not willing to reach a compromise out of court with the club," Charleroi's lawyer Jean-Pierre Deprez told reporters.

Deprez said Charleroi chairman Abbas Bayat met FIFA President Sepp Blatter late on Friday but they were unable to reach agreement.

"We will drop our case if we receive compensation," Deprez said. "The figure is 615,000 euros ($749,100)."

G14 says FIFA regulations unfair

In his opening speech to a Belgium court on Monday, G14 lawyer Jean-Louis Dupont said FIFA should be forced to compensate clubs who have been deprived of players' services because they played in the national team and perhaps subsequently missed club games because of injury while playing at international level.

"The G14 demands 860 million euros in damages from the International Football Federation (FIFA) to cover the losses incurred by the 18 clubs in the G14 over the past 10 years," Dupont said. "This figure covers the cost of putting players at FIFA's disposal and their unavailability after they have been injured while playing for the national team."

FIFA called for a suspension of the hearing, which was refused by the Court. G14, which in the past has often been at loggerheads with soccer's world ruling body, has also called for a revision of FIFA's regulations which they say constitute an abuse of power and violates European law on human rights.

Currently, players who are uninjured and eligible for international duty cannot be retained by their clubs -- a ruling which the G14 feels violates European law.

Article 37 of FIFA's regulations also stipulates that a club which provides players for international duty has no right to financial compensation, and the club alone is responsible for paying any insurance for the player.

G14 thus regard clubs as being sanctioned twice when players return injured from international duty: as well as missing his services they must also continue paying his salary as well as pay for his treatment.

Potentially landmark case

If this case follows the path of the one which changed the face of soccer a decade ago, it could have huge ramifications for FIFA, and the game itself.

Ten years ago, the European courts' Jean-Marc Bosman ruling opened the way for players in Europe to ply their trade openly in any other country affiliated with UEFA.

G14 lawyer Dupont said in spite of the revenue generated by FIFA at this summer's World Cup, none of the clubs who provide players will benefit.

"The World Cup in Germany this year will generate 2.5 billion euros in revenue," he said. "Yet not one euro will be given back to the clubs who have provided the crucial ingredient to this truly global tournament: the players, the employees of the clubs."

The case isn't expected to be decided before the soccer World Cup in Germany this summer and is most likely expected to end up in the European Court of Justice.