Brentford
have completed the signing of West Ham defender El Hadji Malick Diouf in a transfer worth up to £40m.
The 21-year-old Senegal international left-back has agreed a five-year deal, with an option for a further season.
The package sees Brentford pay £35m up front, plus up to £5m in add-ons.
Diouf featured in West Ham’s Championship opener against Burnley, then was left out of the next two squads as negotiations advanced.
He was the Bees’ top defensive target this window, with talks stalling over the summer before being revived earlier this week.
The move takes him back to the Premier League after West Ham’s relegation last season.
His departure delivers West Ham a substantial profit, having signed him from Slavia Prague for £19m just a year ago.
Diouf made 34 appearances for the Hammers last term, contributing five assists.
“He fits our age profile and still has plenty of upside,” Brentford head coach Keith Andrews said.
Diouf said Andrews convinced him he could continue to progress at the club.
Asked about his ambitions with his new team, he replied: “Why not win the league?”
He is Brentford’s fifth arrival of the summer, following striker Callum Wilson, midfielder Mamadou Sangare, centre-back Jannik Schuster and winger Jaidon Anthony.
Having broken into the Senegal squad last year, Diouf played in four World Cup matches this summer.
West Ham went down after finishing 18th, while Brentford impressed under Andrews, ending ninth and missing out on Europe on goal difference.
Brentford opened the season with a 3-0 win over Tottenham Hotspur and face Leeds on Sunday in their next league fixture.