Schalke midfielder Lewis Holtby has announced that he will leave the club at the end of the season when his contract expires.

Holtby joined Schalke in 2009 from Alemannia Aachen and has gone on to establish himself as one of the best young midfielders in Germany.

However, the 22-year-old will now be available on a free transfer this summer.

Schalke was hopeful that Holtby would follow teammate Klaas-Jan Huntelaar in signing a new contract, which the Dutchman did earlier this week.

"We had hoped that Lewis saw his future at Schalke beyond the end of the season. But, like Klaas Jan, he has made a personal decision that we respect," board member Horst Heldt said. "We are sure he will give everything between now and the end of the season."

The Germany international has tallied three goals and five assists in 17 Bundesliga matches this season for Schalke, which sits in seventh place midway through the campaign.