In February, FIFA banned Chelsea from signing players for their men's teams for the next two transfer windows after FIFA's disciplinary committee found the club guilty of breaching regulations relating to the recruitment of minors.

Chelsea denied any wrongdoing and CAS said Friday the club had filed an appeal.

"The Court of Arbitration for Sport (CAS) has registered an appeal filed by Chelsea Football Club Ltd (CFC) against the Federation Internationale de Football Association (FIFA)," CAS said in a statement, adding the club was appealing against the transfer ban.

Chelsea initially appealed to FIFA who partially lifted the ban in April, but only for players under 16 who are not "international transfers and first registrations of foreign minor players".

That left Chelsea still unable to sign male players over the age of 16 when the summer transfer window opens.

Chelsea had been eager to have the ban lifted, or suspended pending an appeal, so they could be in a position to sign a replacement for Belgium's Eden Hazard, who is reportedly on the verge of a move to Spanish giants Real Madrid.

The chances of the appeal being heard before the close of the current transfer window are slim given the normal CAS timetable.

"It is not possible to say at this time when the Arbitral Award will be issued," CAS said in their statement.