* Youth team coach Keller to take over (Updates with more details, quotes)
BERLIN, Dec 16 (Reuters) - Champions League competitors Schalke 04 have sacked coach Huub Stevens after a poor domestic run, culminating in Saturday's 3-1 defeat to Freiburg which saw them drop to seventh in the Bundesliga, the club said on Sunday.
Dutchman Stevens, who will be replaced by youth team coach Jens Keller, was in his second stint at Schalke after taking over in September 2011.
Despite leading the side into the knockout stages of this season's Champions League, Stevens paid the price for a disappointing run of no wins and four defeats in their last six league games and is leaving at the start of the winter break.
"This was a very hard decision for everyone involved given the merits the 59-year-old has earned with the club," Schalke said in a statement.
Stevens had been a crowd favourite ever since leading the success-starved Ruhr valley club to a 1997 UEFA Cup victory and back-to-back German Cup wins from 2001 in his first stint at the club that ended nine years ago.
This season, Schalke started off as Budesliga leaders Bayern Munich's main title rivals but with a busy schedule, the squad has started to show signs of fatigue as the burden of European and domestic campaigns took its toll on the players.
Schalke picked up 20 points in their opening nine matches but added just five more in their next eight games.
Stevens will be succeeded by Keller, who will lead the training on Monday and will be in charge for their German Cup round of 16 tie against Mainz on Tuesday.
Keller had a brief spell in charge of VfB Stuttgart in 2010. (Reporting by Karolos Grohmann; Editing by John O'Brien)