Bayern Munich chairman Karl-Heinz Rummenigge says they're desperate to hold onto Franck Ribery.

The Frenchman, a target for Chelsea and Real Madrid, is out of contract in 2011, but if he doesn't commit himself to a new deal before the summer he is likely to be sold, as Bayern would risk losing him on a free transfer 12 months later.

"Extending Franck's contract is our absolute priority," Rummenigge told the Welt newspaper. "If we had wanted to sell him, we would have had to do that last summer.

"We had some really big offers then, particularly from England. But we all agreed to keep him.

"We want to have the best players at FC Bayern and Franck is currently one of the best in the world.

"We won't throw everything into the mixer, but we will throw in a lot to convince Franck to stay in Munich."