Munich - Argentina defender Martin Demichelis has agreed a new three-year contract at German champions Bayern Munich, club chairman Karl-Heinz Rummenigge was reported Wednesday as saying.

Demichelis, 28, who has been at Bayern since 2003, has been offered a deal keeping him at the club until the end of the 2011/2012 season.

"We have agreed in principle on a contract extension. Martin is staying," Rummenigge was quoted as saying by the Munich newspaper tz.

Germany's Bild newspaper meanwhile reported that Bayern have agreed new one-year contract extensions with captain Mark van Bommel, 32, and fellow midfielder Ze Roberto, 34.

Bayern's injury problems have eased slightly with the return to training of midfielder Franck Ribery. After a two-week injury break with a bruised shin, the France international is expected to be back in the team for Saturday's Bundesliga game at SC Karlsruhe.

Italy striker Luca Toni is also on the way back from an Achilles tendon injury which has sidelined him for four weeks. Toni is running again but is thought unlikely to be ready for the Karlsruhe game.

Bayern, who are second in the Bundesliga, four points behind leaders Hertha Berlin, have problems in attack after Germany striker Miroslav Klose underwent surgery Monday on an ankle ligament injury which will put him out of action for at least six weeks. (dpa)