Sunderland have completed the signing of Anton Ferdinand from West Ham United after he penned a four-year deal."We needed to strengthen our defence and Anton is a great signing," Keane told the club's official website. "He's still young but he has over 160 games under his belt so he has experience, he's learning his trade.
"He'll bring in quality and competition for places which is what we want. Hopefully we can take him to another level here at Sunderland.
"He has come through the ranks at Sunderland and maybe just needs a change."
Ferdinand has a niggling hamstring injury but it is hoped he will be able to make his debut at Wigan on September 13.
