Ferdinand, 23, completed his move to the Stadium of Light club on Wednesday and signed a four-year contract.

The central defender has already been capped at England Under-21 level and has frequently been tipped to join brother Rio in the senior ranks.

Keane believes he can get the best out of the Londoner who has become his ninth summer signing, following deals for Teemu Tainio, Pascal Chimbonda, Steed Malbranque, Nick Colgan, David Meyler, El-Hadji Diouf, David Healy and Djibril Cisse.

Keane told the club's website: "We needed to strengthen our defence and Anton is a great signing.

"He'll bring 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 West ham and maybe just needs a change."

Sunderland have started their Premier League campaign with a home defeat to Liverpool and away win at Tottenham, and Ferdinand is likely to be available for the game at Wigan on September 13.

He is currently recovering from a hamstring strain, and is convinced he has made the right move by heading north.

"It was hard leaving West Ham because I have been there for 16 years but after meeting Roy Keane I knew it was time for a change," Ferdinand said.

"This is a great challenge for me and I feel it is an exciting time at Sunderland. I think the move will do me good."

With Ferdinand arriving at Sunderland, Keane allowed Scotland centre-back Russell Anderson to join Burnley on loan for the season on Tuesday.

However he still wants to add to his squad before the transfer window closes next week.

Keane explained: "I have one more player in mind and then that is the end of it for a few months at least."