The 22-year-old has been on the fringes of the starting XI at the Stade Velodrome this season, and has notched just once in 16 league appearances this term.
Sochaux are struggling at the wrong end of the Ligue 1 table. A return of just two victories has left Herve Renard's charges in 19th position with just 11 points.
Ayew is now set to pen a temporary deal until the end of the campaign and add firepower to a team that has scored just 15 Ligue 1 goals this season.
A statement on the club's official website read: "An agreement in principle was reached between Marseille and Sochaux for the loan until the end of the season of Jordan Ayew.
"The arrival of the Ghana international striker at FC Sochaux is now conditional on the medical examination."
Ayew made his debut for Marseille in December 2009 after coming through the youth ranks at the club.
