West Ham have announced they have signed Sunderland defender George McCartney on a two-year contract for what will be his third spell at Upton Park.
The 31-year-old came through the youth system at Sunderland before moving to the Hammers where he spent two years from 2006 to 2008 before rejoining the Black Cats.
McCartney then enjoyed a successful season-long loan in east London last season as the Hammers made an immediate return to the Barclays Premier League.
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."
The former Northern Ireland international excelled during his first stay in east London, scoring once in 71 appearances in all competitions. After moving back to the Stadium of Light in 2008, McCartney spent two seasons with Sunderland and one on loan at Leeds.
Having fallen out of favour on Wearside, the 31-year-old returned to West Ham on loan in August 2011, scoring one goal in 43 appearances in all competitions. The Hammers also announced that Julien Faubert has left for Turkish side Elazigspor after five years with the club which also included a loan spell with Real Madrid.
Czech Republic Under-21 goalkeeper Marek Stech has also left, having made three appearances in the Carling Cup in his six years in east London.