The possibility of Rossi leaving Michelin for Bridgestone seemed to have already been ruled out by the Japanese tyre manufacturer, and then by Fiat Yamaha team director Davide Brivio, but the Italian superstar today revealed that the situation is still "in progress" with a final decision yet to be made.

Meanwhile, in a related development, the likelihood of a single tyre rule in MotoGP next year seems to be reducing.

The main reason given for proposing the radical rule - already present in WSBK and F1 - was due to some factories being unable to acquire the tyres that they want for 2008.

Casey Stoner, Ducati and Bridgestone ended Michelin's 15-year run of MotoGP title success this season and, with all the Bridgestone-backed factory teams happy to remain on the Japanese rubber, that left only Honda and Yamaha as the possible 'unhappy' factories in question.

Both have since suggested that they were reacting to requests from their riders - of whom Rossi and Repsol Honda's Dani Pedrosa are believed to be the most keen to change. Pedrosa's team-mate Nicky Hayden appears more prepared to stick with Michelin, while it is unknown how much influence Rossi's 2008 team-mate Jorge Lorenzo has in terms of tyre supply.

If Bridgestone agree to supply Rossi and/or Pedrosa next season, then the main reason for proposing the single tyre rule will be gone. But the problem will then be how to persuade Michelin to remain after the loss of at least one of its main stars and the potential difficulty of having team-mates on different brands of tyre.

Michelin has previously stated that it will withdraw from MotoGP if it loses either the Honda or Yamaha factory teams, while Dunlop is fighting to remain in the class after Tech 3's expected move to Michelin.