Sunderland have confirmed that they have signed Ivorian defender Lamine Kone on a three-and-a-half-year deal from French side Lorient.
The 26-year-old, who has been subject of a protracted on-off saga between the two sides this transfer window, will wear the number 23 shirt at the Stadium of Light.
"Strengthening our defensive options was a priority for us and Lamine is a player that has impressed me when I've seen him play," manager Sam Allardyce told the club's official website.
"He is big and strong, attributes you need to play in central defence in the Premier League, and his arrival will give us healthy competition for places in a key position."
Kone, who is believed to have cost the North-East side £5m, joins with the Black Cats 19th in the Premier League and four points from safety.
