Bayern Munich chairman Karl-Heinz Rummenigge says the club are willing to 'invest a lot' to keep Franck Ribery at the Allianz Arena.

The France international has been persistently linked with Europe's other top clubs, including Manchester United, Real Madrid, Barcelona and Chelsea.

The 26-year-old has a contract with the German giants until June 2011 and the Bayern chairman says the club are keen to extend it.

Rummenigge told Munich daily newspapers AZ and TZ: "Our goal is to prolong Franck's contract; I will do as much as I can to keep him in Bayern."

The French playmaker has been out since the start of October with a persistent knee injury.

He is not expected to play until Bayern's Bundesliga match at Bremen on 23rd January as - while the knee injury has now healed - in-growing toe nails on both feet have restricted Ribery's training so far this year.

Despite his absence, Rummenigge has hailed the player's importance to the club, who face a UEFA Champions League last 16 clash against Fiorentina next month.

The chairman added: "Louis van Gaal (Bayern's coach) has said he is convinced of Ribery's talent and his importance for Bayern.

"Franck is without question the best player in the Bundesliga."