Ralf Schumacher has backed his older brother Michael to remain in F1 beyond the end of the current season.

The seven-time champion is out of contract at the end of the year having signed a three-year deal with Mercedes when he came out of retirement for the 2010 season.

So far, Schumacher has been outperformed by team-mate Nico Rosberg with doubts existing about whether or not he would elect to extend his existing deal and remain with the team for a fourth season.

However, speaking to Bild am Sonntag, former Toyota and Williams driver Ralf - now competing in the DTM - said he was sure his title-winning brother would continue in the sport.

"For sure Michael came back to celebrate successes with Mercedes," he said, "and until he succeeds, he will not give up. I still see a lot of fire in Michael. He is pushing hard, as we saw as recently as Mugello last week.

"I think we will see Michael on the podium soon. At some point, there surely comes a point when the body can't do it any more. But when I look at Michael, that's still a few years away. I certainly won't be racing as long as he has."