Charlton have completed the signing of Senegal and Sochaux centre-back Souleymane Diawara on a four-year deal for a fee of £3.7m.
Diawara played in the Uefa Cup with Sochaux
The 27-year-old, who previously played for Le Havre, is Charlton's eighth signing of the summer transfer window.
"He's is a player I've long identified as a top defender," Addicks boss Iain Dowie told the club's official website.
"He's got great pace, good ability on the ball is very powerful and will be well suited to the Premier League."
Injuries to centre-backs Gonzalo Sorondo and Jonathan Fortune, and a three-match ban for Hermann Hreidarsson have seen Dowie move for extra cover before the transfer window closes on Thursday.
"We think he's a huge defensive addition to our squad," added Dowie.
Diawara was born in Gabou, but holds a French passport and will not require international clearance.
He helped Sochaux win the French League Cup, and played in the Uefa Cup the following season.
The fee paid for Diawarra is the fifth highest in Charlton's history.