Stefano Domenicali on Sunday indicated that Avon-Cooper and Bridgestone are no longer in the running to supply formula one tyres next year.
The Ferrari boss was discussing with the media Sunday's series of meetings at Monaco, where a decision about the departing Bridgestone's 2011 replacement was again deferred.
"It will probably take another week," the Italian is quoted by Germany's Motorsport-Magazin.com. "Perhaps next weekend."
Avon was among those who have submitted formal proposals, and in recent days the teams have been pushing Bridgestone to reconsider its decision not to seek a new contract as the sport's official sole supplier.
But Domenicali revealed: "There are only two possibilities; Michelin and Pirelli."