Gillet, the best a Nantes can get.
Gillet, 31, who plies his trade either as a right-sided full-back or deep-lying midfielder, has made 19 league appearances for the Purple and White this season, chipping in with three goals.
The move isn't the 21-time-capped international's first foray into French football, as he played in all 38 of Bastia's matches last season, on loan from Anderlecht.
A statement on Nantes' website suggests that GIllet will join the club at Joneliere for a medical on Jan. 3, before meeting up with his new teammates for winter training on Jan. 5. The club did not disclose the conditions of the transfer.