Marseille have claimed that Lyon full back Francois Clerc agreed to join them.
Marseille have claimed that Lyon full back Francois Clerc has a written agreement to move to Stade Velodrome.
Clerc appeared to end the uncertainty surrounding his future earlier this week by signing a new four-year contract at Lyon.
The youngster would have been a free agent in the summer, but opted to stay with the French champions in the wake of interest from Marseille.
But l'OM chairman Pape Diouf has revealed Clerc had agreed to move to the South Coast and the club are now considering what action they may be able to take.
"We have a written agreement from the player," Diouf told L'Equipe.
"We have followed the Fifa rules, which state we can contact a player six months before the end of his contract.
"But it doesn't get implemented in France. We will take stock with our legal specialists."
Diouf also confirmed the plan to retain coach Jean Fernandez for next season, despite an uneasy relationship with Marseille's sporting director Jose Anigo.
"To me, there is no doubt that Jean Fernandez will still be here next season," added Diouf.
"The relationship between Fernandez and Anigo? I believe it is more of a trouble of character.
"I have noticed no interference from Jose Anigo in the technical area. If there are adjustments to set between Jean and Jose, I will set them because it is true a relationship is important.
"Anyway, we are all meeting regularly to prepare for next season."
Marseille are also chasing the signature of Caen's Ronald Zubar and Palmeiras' Marcinho Guerreiro, although Diouf played down talk that deals are close to completion.
He concluded: "Nothing has been settled and we don't want to rush."
