The Court of Arbitration for Sport has rejected an appeal by Marseille over the legality of midfielder Mathieu Flamini's transfer to Arsenal.
Flamini, 21, came through the Marseille youth ranks but signed his first professional deal with Arsenal in 2004.
Despite a dispute, Fifa authorised the player's transfer but Marseille wanted the decision overturned so they could reinstate Flamini into their squad.
But the CAS said it "dismissed the appeal filed by Marseille."
A statement on the CAS on its website also "confirmed the authorisation granted by Fifa to Arsenal to register the player Mathieu Flamini".
"The CAS has also confirmed the training compensation of $480,000 allocated to Olympique de Marseille by Fifa," the CAS added.
Flamini has made 12 appearances for Arsenal this season and the Gunners are pleased that the matter is now closed.
An Arsenal statement read: "We are pleased that the Court of Arbitration for Sport has supported Fifa's decision and rejected the claims of Olympique Marseille.
"The decision shows that Arsenal Football Club and Mathieu Flamini have at all times acted appropriately in this matter.
"Both the club and the player are looking forward to putting this behind them and moving on."