Ferrari boss Luca de Montezemolo on Thursday confirmed that the Italian team will not race in Formula One next season unless new rules are changed.

''We've decided not to run in F3,'' he said, implying that a defection of top teams would demote the championship's status.

''If Formula 1 becomes Formula 3 we won't compete,'' he said a day after a French court rejected a Ferrari injunction against rule changes including a budget cap that top teams contend would create a two-tier championship.