A profound disagreement" with Formula One bosses has led to French tire manufacturer Michelin deserting Grand Prix racing after the 2006 season.
Michelin, who announced their decision on Wednesday, were against a decision by F1 authorities to move to a single tire supplier in 2007.
They also clashed after the fiasco at the U.S. Grand Prix earlier this year when the seven Michelin-shod teams withdrew due to tire safety concerns at Indianapolis.
Japanese rival Bridgestone is left in pole position to be the sole supplier. In 2006 the 10 Formula One teams will be evenly split between the two manufacturers.
"This decision is the result of the realization that there is a profound disagreement between the sports philosophy that has always been driving Michelin and the management practices of the F1 authorities," company boss Edouard Michelin said in a statement.
He said that the uncertainty thrown up by the F1 authorities did not give sufficient guarantees to justify long-term investments.
The French group said that after consultations with its teams -- McLaren/Mercedes, BMW/Sauber, Renault F1 and Honda Racing F1 -- it seemed the move to one tire supplier was "unavoidable".
It promised full support to the teams in 2006 and said it could come back to the sport if the rules were changed "profoundly" in the future.
The FIA expressed gratitude to Michelin for their contribution but pointed out the teams had "repeatedly and unanimously" requested a single tyre supplier.
The governing body said teams would be glad to have their wish granted earlier than expected.
"A single tyre supplier will undoubtedly make Formula One fairer, safer and less expensive for the teams but, above all, it will avoid a repetition of the problem which arose at the 2005 U.S. Grand Prix," it added.