Ferrari are second in their championship, 19 points behind champions Renault. Schumacher has won two of the six races.

Ferrari boss Jean Todt said in a statement at the Monaco Grand Prix that he took note of Rossi's decision.

"It was a pleasure giving him the chance to try out a Ferrari racing car," he said. "All those who worked with him were struck by his ability to adapt to Formula One, by his talent and courtesy.

"Now we will follow with great affection his MotoGP challenge, hoping that he can get what he so richly deserves."

Schumacher had mixed feelings. "In a way we are sad not to see him here. On the other side, it's understandable," the German told reporters.

"Probably he thinks he knows what he has in his world and it may be a little bit more difficult to know the world of Formula One and how he may adapt to all the different circumstances, although I think he has a very high talent and could have done it in terms of driving.

"But then it's not only the driving, there's a lot of other things besides," said Schumacher.

Renault's world champion Fernando Alonso, who incurred Rossi's ire earlier in the year when he said he could do just as well on bikes as the Italian in cars, was unmoved by the news.

"Good. Like this we don't talk anything more about him," said the Spaniard.