Sunderland have completed the signing of midfielder Alfred N'Diaye from Turkish club Bursaspor for an undisclosed fee after completing his medical and agreeing personal terms.
The 22-year-old can play in a defensive midfield role or at centre-back and arrived at Wearside after moving to Turkey from Ligue 1 side Nancy last year for a fee reported to be in the region of £3m.
N'Diaye, a France Under-21 international, signed a three-and-a-half year deal at the Stadium of Light to become Sunderland manager Martin O'Neill's first January signing for the struggling Black Cats.
O'Neill said: "Alfred is a strong, powerful young player and as such can offer us more strength in depth.
"He will give us options and I'm delighted that we have been able to bring him to the club."