Manchester United have completed the signing of Dutch defender Alexander Buttner from Vitesse Arnhem.
The 23-year-old has agreed personal terms and joins on a five-year contract until 2017.
Red Devils manager Sir Alex Ferguson told the club's official website: "Alexander is one of the best young left-backs in Europe and we're delighted to sign him.
"He's someone we've been watching for a while now. He gives us some really exciting options in that position."