Rome: MotoGP world champion Valentino Rossi said he was moving to Italian team Ducati because his work with Yamaha was finished and they no longer needed him.
Rossi, one of Italy`s most famous sports personalities, will race for Ducati next year on a two-year contract. He has been with Yamaha since 2004.
He told reporters on Monday at the Czech circuit in Brno, scene of Sunday`s Grand Prix:
"I`m happy, I`m very curious and very motivated. This new challenge, I think, will be very interesting -- especially because I think that at Yamaha my work is finished."
Rossi added: "We changed the situation from 2004 a lot. Yamaha have great riders so it looks like they don`t need me any more."
Clear championship leader Jorge Lorenzo of Spain also rides for Yamaha.
A vacancy at Ducati arose after Australia`s Casey Stoner said last month he would be leaving for Honda next year.
Looking forward to 2011, Rossi said: "I think an Italian rider on an Italian bike is great for all the Italian fans and I think we will have a lot of cheering from all the Italian fans."
Yamaha managing director Lin Jarvis added: "Unfortunately he`s made finally the choice to go and ride for Ducati next year so it was a sad day yesterday because although we`ve known about his decision for some weeks nevertheless when you make the final public announcement it becomes a fact."