The Factory Yamaha Team, which raced without a title sponsor in MotoGP this season, will be without Petronas backing in 2012.
The Malaysian oil and gas corporation came on-board with Yamaha in 2009 (when Fiat was the title sponsor) and thus shared in two consecutive Triple Crown MotoGP victories - the Riders', Constructors and Teams' titles - in 2009 and 2010.
This year saw reigning champion Jorge Lorenzo and new team-mate Ben Spies win four races and finish second and fifth in the championship standings respectively.
Lin Jarvis, managing director of Yamaha Motor Racing, said the partnership had reached its 'natural conclusion'.
“The relationship between Yamaha and Petronas has been a great success, we have enjoyed some major achievements together in the MotoGP class,” said Jarvis.
“Now that the partnership has reached its natural conclusion I would like to thank our friends at Petronas for the support during their time with us and wish them well for the future”.
In the absence of a title sponsor, Petronas had been the biggest non-Yamaha branding on the factory M1s.