Koller to leave Dortmund

Borussia Dortmund's Jan Koller will not be extending his contract.

Borussia Dortmund striker Jan Koller has turned down a lucrative contract with the club, which will allow him to leave the side on a free transfer next summer.

Dortmund had offered the Czech international a new contract but, after much deliberation, he has refused stating that he is looking for new challenges abroad.

"Together with the club's superb fans I want to enjoy a fine season and end my spell with a successful outcome," Koller told the club's official website.

The club's director of sport, Michael Zorc, was disappointed that Koller, who is popular with the fans, will not be staying.

"We regret his decision not accept our offer for a new contract, but will have to accept it," he commented.

Koller joined Borussia Dortmund in 2001 from Belgian side Anderlecht and played a vital role in helping them lift the Bundesliga title the following year.

It is thought the 32-year-old striker will head to England when his contract runs out next summer, having been linked with Sunderland earlier this year.