Kakuta, 18, joined Chelsea from French side Lens in 2007
Chelsea's transfer ban has been temporarily suspended by the Court of Arbitration for Sport (Cas) pending a final decision on the matter.
Fifa had ruled the club could not sign players until 2011 after inducing Gael Kakuta to break his Lens contract.
But Chelsea appealed to Cas, which said on Friday: "Such sanctions are now stayed until the Cas renders its final decision in this matter."
The decision means Chelsea will be able to sign players in January.
No date has been given for a final decision from Cas but the case is not expected to be concluded until spring of next year.
Fifa had banned the Premier League leaders in September from any activity during the next two transfer windows after they were found guilty of inducing Kakuta, now aged 18, to breach his contract with French club Lens in 2007.
Under the terms of the original Fifa punishment, French teenager Kakuta was ordered to pay compensation of 780,000 euros (£710,000), for which Chelsea were "jointly and severally liable".
Chelsea were also told to pay Lens "training compensation" of 130,000 euros (£118,000).