Bastia have secured the return of Guinea international Sadio Diallo from Ligue 1 rivals Rennes.
The attacking midfielder has spent the last two season on loan at Lorient, having left Bastia for Rennes in 2012.
Diallo arrives on a three-year contract after passing a medical.
The 24-year-old helped Bastia climb from the third tier to the top flight during his previous spell at the club.