"The superior appeal commission has suspended Leonardo until June 30, 2014," the FFF said in statement on Thursday.
Television footage showed the Brazilian bumping into referee Alexandre Castro with his left shoulder in the Parc des Princes tunnel after PSG drew 1-1 with Valenciennes in a Ligue 1 encounter in May.
The French champions, who were also handed a suspended three-point deduction, had appealed the initial nine-month ban imposed by the French League.
They are yet to decide whether to appeal to the national sporting and Olympic committee - the CNOSF - which is the highest sports authority in France.
"Paris St Germain ... regret the harshness of the sanction against Leonardo who still has the full confidence of the club," the French champions said in a statement on Friday.
"The club will decide whether they file a possible appeal (to the CNOSF) after examining the reasoned decision."
- Sports & Recreation