Valentino Rossi looks set to switch to Bridgestone tyres for 2008, with paddock sources at Sepang indicating that a deal has been finalised with the Japanese company.
The former champion wanted the same tyres as title winner Stoner for next year after the problems he encountered with Michelins throughout this season.
Finishing 30 seconds behind US GP winner Stoner, and yet still being fourth and the top Michelin finisher at Laguna Seca was believed to be the final straw for the Italian.
Autosport.com understands that the deal is done and that the paperwork just needs to be signed and sealed ready for an announcement next Wednesday.
Rossi's move is likely to avert the possibility of a single tyre rule being implemented in MotoGP. A decision had been due on this matter during the Sepang weekend, although with just 18 days remaining before the end of the season it seemed unlikely to be adopted.
The deal means that Rossi will be the sole Yamaha on Bridgestones and therefore the first-ever Yamaha MotoGP bike to use them, while the other three works Yamahas next year will continue on Michelins.