West Ham United have announced the signing of Sunderland fullback George McCartney.

The Northern Irishman becomes the club's fourth summer capture following the arrivals of goalkeepers Jussi Jaaskelainen and Stephen Henderson from Bolton and Portsmouth respectively and Senegal midfielder Mohamed Diame from Wigan.

"I am delighted to be coming back to West Ham and this time on a permanent basis," said the Belfast-born full-back, who won West Ham's Players' Player of the Year award last season.

"It was great to be part of the side that won promotion for the club last season.

"It was a fantastic way to end the campaign last year and I am really looking forward to being back in the Premier League with West Ham."