Chesea have announced they will "mount the strongest appeal possible" against FIFA's decision to ban them from making any signings during the next two transfer windows.

A club statement read: "The sanctions are without precedent to this level and totally disproportionate to the alleged offence and the financial penalty imposed."

The club will appeal to the Court of Arbitration for Sport after the game's governing body punished them for persuading French star Gael Kakuta to break his deal with Lens.

Kakuta was signed by the Blues from Lens in 2007 during the reign of Jose Mourinho and sparked a row when the French club claimed his move was a breach of contract.

Lens lodged a claim with FIFA's Dispute Resolution Chamber seeking compensation for breach of contract from the player and asking for action to be taken against the star and Chelsea.

In a statement issued this afternoon, FIFA said: “The DRC found that the player had indeed breached a contract signed with the French club.
Equally, the DRC deemed it to be established that the English club induced the player.

“As a result the player was condemned to pay compensation in the amount of £682,000, for which the club, Chelsea, are jointly and severally liable — and sporting sanctions were imposed on both the player and Chelsea.

“A restriction of four months on his eligibility to play in official matches is imposed on the player while Chelsea are banned from registering any new players, either nationally or internationally, for the two next entire and consecutive registration periods following the notification of the present decision.”

It means Chelsea, who must also pay Lens £113,995, can't sign any new players until January 2011 which potentially could cost them the chance of winning the Premier League title.

Kakuta, an 18-year-old winger, had an impressive start for Chelsea, scoring 12 goals in 24 youth game appearances but has been out since February after breaking his ankle in a friendly against the Glenn Hoddle Academy.

Gael Kakuta in action