Formula1's comeback king Michael Schumacher wants to win his eighth World title - though he concedes he might not do it this season.

The 41-year-old has signed a three-year deal to come out of retirement to race for Mercedes GP. His previous last race in F1 was with Ferrari in 2006 when finished second in the Drivers' championship behind Renault's Fernando Alonso..

Schumacher told German newspaper Bild: "In our long-term targets with Mercedes, we have a clear objective: I want to become World champion again. Perhaps that will not happen in my first season back but it is realistic over the three seasons."

Schumacher won 91 GP's up to his retirement in October 2006. He admitted that he missed the buzz of F1 driving: "When I went to F1races (after retiring), I was more annoyed than frustrated at not racing," he said.

Despite his advancing years, he says age will not be a factor when he returns to racing on March 14 in Bahrain.

"Apparently I've succeeded in pushing back the effects of aging, I must have good genes," he added.