Ekwah, who made 40 appearances for the Black Cats last season, has fallen down the pecking order under new head coach Regis Le Bris due to injuries and the form of Chris Rigg, Jobe Bellingham and Dan Neil, in addition to summer signing Alan Browne.
According to the Sunderland Echo, several clubs from England and abroad have expressed interest in Ekwah, including Udinese and Premier League teams Crystal Palace, Fulham and Leicester. However, Saint Étienne has won the race to sign the midfielder.
Reportedly, a busy deadline day is expected on Wearside, with several players coming and going as coach Regis Le Bris shapes his team for the rest of the season. Sunderland currently sits at the top of the Championship.