Defender Billy Jones has signed a four-year contract with Sunderland, having rejected a new deal with West Brom.
The versatile 27-year-old began his career at Crewe, moved on to Preston and then had a three-year stint at the Hawthorns.
However, he has now decided to move on and told the Sunderland website on Wednesday: "I'm really happy to be here and I'm looking forward to getting back for pre-season and kicking on.
"I've played at the Stadium of Light a number of times so I know what it's about and what great backing the club has.
"I've come to the training ground today and it's amazing. I knew I was signing for a massive club with everything in place to kick on up the league and carry on moving forward."
The West Brom website reported: "Billy Jones has rejected Albion's final contract offer and joined Barclays Premier League rivals Sunderland on a Bosman.
"The club are now pursuing other targets they have been monitoring in the right-back position."
Director of football administration Richard Garlick added: "Following further talks with Billy's representative, we made our final offer last week - a long-term deal on vastly-improved terms based on Billy's contribution over the past three years.
"Billy rejected this and has exercised his right to run down his contract with a view to joining Sunderland.
"We're obviously disappointed by Billy's decision but wish him well in his future career.
"With there being no guarantees that Billy would re-sign, we have been preparing for this scenario and will pursue the options we have been exploring in the right-back position."