Borussia Dortmund have parted company with under-23 coach David Wagner, who has been tipped to reunite with Jurgen Klopp at Liverpool.
Wagner joined Dortmund from Hoffenheim, where he had coached the under-19 side, in 2011.
He secured promotion to Germany's third tier in his first year at BVB, although the club's under-23s were relegated last season.
Following a 1-0 home defeat to TuS Erndtebruck at the weekend -- a result which leaves Dortmund's under-23s in the relegation zone -- Wagner's exit was confirmed.
"Borussia Dortmund are an extraordinary club with fantastic fans. In spite of that I seek a new sporting challenge after a great time at Dortmund," Wagner said in a Dortmund statement.
The statement added that Wagner had made the step "to enter contract negotiations" with other clubs.
When Klopp joined Liverpool in October, local media in Dortmund reported that Wagner could follow his old boss to Anfield.
Wagner was Klopp's best man at his wedding, while the Reds boss is the godfather of his former colleague's youngest daughter, with their friendship dating back to their days as players at Mainz.
Wagner told Dortmund fanzine schwatzgelb.de last month that he is not immediately joining Klopp's backroom staff at Liverpool, but did not rule out a future move.