Carlo Ancelotti will step up his pursuit of Chelsea's summer transfer targets after the club's ban on making new signings was lifted.
The Court of Arbitration for Sport (CAS) on Thursday night found in the Barclays Premier League leaders' favour after FIFA had prohibited any transfer activity until 2011.
FIFA issued the punishment after agreeing with Lens that Chelsea had induced Gael Kakuta to break his contract with the French club. But the CAS review cleared the Blues of any wrongdoing on the grounds that the contract between Kakuta and Lens was not valid.
The initial embargo was suspended by CAS in November, enabling Chelsea to conduct business in the January transfer window which closed on Monday.
As promised, Ancelotti opted against bringing in reinforcements but crucially the removal of the restriction enables the Italian to strengthen during the summer.
The CAS decision comes after new evidence of Kakuta's first contract with Lens came to light, and FIFA have also recognised the CAS ruling. Both FIFA and Chelsea were advised during the case by Peter Hargitay, the London-based consultant who was until 2008 special adviser to FIFA president Sepp Blatter.
Chelsea chairman Bruce Buck said: "We are pleased to have come to an amicable resolution of the matter and that it has been ratified by CAS and recognised by FIFA.
"It was always our intention to work together with Lens to reach this end.
"Both clubs have strengthened their relationship as a result of resolving this case to everyone's satisfaction.
"In an act of good faith and with a view to the possibility of future collaboration with Lens, and without recognising any liability, Chelsea has agreed to pay compensation costs for the training given to the player while at Lens, as mandated by FIFA in its original ruling."