Sunderland have confirmed the signing of Lamine Kone from Lorient for an undisclosed fee.
Ivory Coast defender Kone, 26, has signed a contract at the Stadium of Light until 2020.
- Sunderland AFC (@SunderlandAFC) January 27, 2016
Sunderland boss Sam Allardyce said he hoped the centre-back would be a valuable addition as they look to avoid relegation.
"Strengthening our defensive options was a priority for us and Lamine is a player that has impressed me when I've seen him play," Allardyce said on 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."
Sunderland had already moved to reinforce their defence this month with the signing of Jan Kirchhoff from Bayern Munich.