Chelsea have hit out at FIFA for treating them "entirely differently to Manchester City" over transfer breaches after the London club had their registration ban halved by the Court of Arbitration for Sport (CAS).

The Premier League side were banned from registering new players for two successive transfer windows by FIFA in February, a punishment handed down for breaching rules related to acquiring and registering players under the age of 18.

An appeal to FIFA had been partially upheld, allowing them to sign players 16 or younger, but Friday's announcement means they will now be able to buy reinforcements for their senior team in January.

Chelsea have since taken the opportunity to lambast FIFA's treatment of them, convinced they were dealt a crueller hand than Manchester City, who avoided a transfer ban in August despite the world's governing body finding them to have breached rules on under-18 signings.

A Chelsea statement read: "Chelsea is grateful to the CAS for the diligent approach that it gave this matter. The club has not yet received the written reasons for CAS's decision but wishes to make the following clear: The approach taken by FIFA to this case has been deeply unsatisfactory, not least as FIFA chose to treat Chelsea entirely differently to Manchester City for reasons that make absolutely no sense to Chelsea."

Chelsea were investigated for their conduct in relation to 27 signings from 2009 onwards, with the club understanding 16 of them were registered "in exactly the same way as other Premier League clubs registered players at the time".

The club claim they received guidance from the Football Association (FA) that no special application was required for those players, yet FIFA still opted to bring charges against them, a decision Chelsea called "perverse".

The other five players in question were only "deemed" by FIFA to have been registered prior to a registration application being made, with CAS ruling the world's governing body is not permitted to make judgements based on "deemed registrations".

Chelsea's statement finished with another criticism of FIFA and a perceived history of imposing "inconsistent and unequal sanctions", suggesting the world football will lose faith in their governance of such issues if they fail to improve their methods, seemingly referencing their handling of Manchester City's case.

City were fined £314,000 in August for breaking rules relating to the transfers and registration of young players, but they avoided a transfer ban.

While many expected City to suffer a similar fate to Chelsea, the Premier League champions accepted responsibility for the breaches, which were reported to have involved two only players.

However, Chelsea denied wrongdoing when FIFA initially charged them for breaches involving 27 players.