Jeremain Lens has said that he is "very happy" to have completed a move to Sunderland, reuniting him with Dick Advocaat.
The Dutch international, who moves to the Stadium of Light on a four-year contract from Dynamo Kiev, played under the Black Cats head coach during spells with PSV Eindhoven and AZ Alkmaar.
The 27-year-old told the club's website: "I'm very happy to be a Sunderland player. I think it is a good club and it is a great step for me to play in the Barclays Premier League. I followed the team last season following the arrival of Dick Advocaat and we have a good team, so as I said I'm really happy to be here.
"I've played for the Dutch national team and played a lot of games in Europe, but the Barclays Premier League is the main test so it will be really good to play some games here.
"I watched the derby against Newcastle United and the supporters were really amazing, so I've got a good impression of the fans and I hope they support us in the same way during the new season."
Lens scored three goals in just 12 appearances for the Ukrainian side last season.