Yaya Toure was a key performer for Ivory Coast at the World Cup
Ivory Coast international Yaya Toure has joined former French champions Monaco from Greek side Olympiakos.
The 23-year-old midfielder has signed a four-year contract with the first division side.
Monaco paid Olympiakos just over US$5.75m for Toure, whose transfer was delayed because his rights belonged to both the Greek champions and Metallurg Donetsk of Ukraine.
The Ivorian represented Metallurg for two seasons from 2003 before joining Olympiakos last year, with whom he won a league and cup double.
"Monaco and the clubs of Olympiakos and Metallurg Donetsk have reached an agreement concerning the transfer of Yaya Toure," Monaco said in a statement.
Toure, who played all three of the Elephants' World Cup games in June, began his career with Asec in Abidjan before signing for Beveren in Belgium as a 19-year-old.
The tall midfielder, the younger brother of Arsenal defender Kolo Toure, has won 17 caps for his country and scored three goals for his Greek club last season.
He joins a side who have made a poor start to the French league season, with Monaco lying joint bottom after losing their first two matches.