Honda's Australian rider Casey Stoner will replace Sete Gibernau at Italian MotoGP outfit Ducati in 2007.
Stoner is completing his first season in MotoGP
Gibernau, 33, has failed to capture his best form this campaign and is out of the season-ending race in Valencia after crashing in Portugal last week.
The Spaniard collided with Stoner and broke a collarbone and hand.
Ducati MotoGP boss Claudio Domenicali said: "Despite his devotion and talent, a number of factors have prevented Sete from living up to our expectations."
He added: "This season has proved to have been particularly difficult for Sete, but our heartfelt thanks go out to him for his commitment and professionalism and we wish him all the best for his future."
He is a very promising rider, with talent and determination in abundance
Ducati MotoGP boss Domencali on Stoner
Stoner, who moved up to MotoGP at the start of the year, displayed his potential in his first season with a second-place finish in the Turkish GP.
And, with next season seeing the 800cc bikes taking the place of the 990cc powered machines, Domencali has tipped the 21-year-old to excel.
"He is a very promising rider, with talent and determination in abundance," he said.
"We are sure that with the help of our and Loris Capirossi's experience, he will get to know our bike and his experience will mature in line with the development of the GP7 bike."
Stoner, who has signed a one-year deal with an option of an extension, added: "I am really happy to have been given this opportunity to race with the Ducati MotoGP Team next year.
"I think they can also do a great job with the new 800 (cc) and it's a great privilege for me to be Loris Capirossi's team-mate."
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