West Ham have announced the signing of Swiss midfielder Edimilson Fernandes from FC Sion.
Sources close to the club told ESPN FC on Wednesday that the teams had agreed a £5.5 million fee.
The 20-year-old was introduced on the pitch of the London Stadium before Thursday evening's Europa League qualifier against Romanians Astra Giurgiu.
- West Ham United (@WestHamUtd) August 25, 2016
Fernandes, the cousin of former Manchester City and Leicester midfielder Gelson Fernandes, becomes manager Slaven Bilic's ninth signing of the summer.
He has put pen to paper on a four-year contract with the Hammers.