Former France international Diarra, now 39, has been embroiled in a series of legal battles since the club terminated his contract with Lokomotiv Moscow in 2014.
Following a dispute with coach Leonid Kuchuk, Lokomotiv alleged that Diarra refused to show up for training or accept a lower salary and fired him three years before his contract expired.
In 2016, a FIFA ruling, backed by the Court of Arbitration for Sport (CAS), found Diarra liable for breach of contract, ordered him to pay €10m (£8.4m) to Lokomotiv and suspended him. of professional football for 15 months. .
When Diarra reached an agreement to join Charleroi, the club asked for guarantees that they would not be obliged to pay any compensation to Lokomotiv.
FIFA then refused to grant Charleroi a CTI, required by clubs around the world to register a newly signed player, so the deal collapsed.
Diarra’s lawyers challenged this specific rule, which makes a club wishing to sign a player jointly and severally liable for compensation to the player’s former club, and at risk of sporting sanctions, in cases where the player’s previous contract has been terminated without just cause.
They also questioned a rule allowing the national association of a player’s former club to retain a CTI when there was a dispute, which they said also hampered the move.
The court has ruled that FIFA should not be able to use the ITC system to prevent players who have breached a contract from moving and working where they choose.
Parts of FIFA’s transfer rules will have to be revised to remain valid in the EU.
