Skipper Van Bommel, whose deal was due to expire at the end of the season, will stay with Bayern until June 2010.

"We have agreed a one-year contract extension with Mark," the club's general manager Uli Hoeness said.

The Dutch midfielder joined Bayern from Barcelona in 2006 and established himself as a key player in the Bavarians' squad.

Argentinean defender Demichelis has also committed his future to Bayern, prolonging his stay until 2012.

"I'm delighted we've reached agreement, and I'm looking forward to achieving a great deal with Bayern," Demichelis, who joined Bayern in 2003, said.