Marco Melandri has parted ways with Aprilia MotoGP team with immediate effect. This is primarily due to a poor season of racing.
Melandri struggled to get the motorcycle set up right, which has its roots in the ART CRT design ahead of the launch of an all-new factory machine next year.
Melandri has qualified towards the end in every race this season and has not finished above 18th place.
A statement from Aprilia said the two parties had "reached an agreement by mutual consent to terminate the contractual obligations".
Melandri was the 2005 MotoGP runner-up and won six grands prix in his early career at the top level. Replacing him to ride alongside Alvaro Bautista could be Michael Laverty, who tested the Aprilia last year.