Sochaux ask FIFA to act over Maiga
"Sochaux sent a referral on Monday to FIFA asking that Newcastle United stop their contact with Modibo Maiga, contractually bound to Sochaux until 2014," said a statement on the club's website.
The Mali international, 23, refused to play in Sochaux's last two Ligue 1 matches and the Europa League play-off game against Metalist Kharkov. He has also stopped attending training.
"The move comes after Sochaux twice formally but unsuccessfully asked the English club to end their actions," the club statement added.
Midfielder Kevin Anin also boycotted Sochaux's last league match, a 2-1 win at Nancy, as he seeks a move. Both players have the same agent.
Newcastle were not immediately available for comment.