Ferrari boss Luca Cordero di Montezemolo on Wednesday ruled out a new Grand Prix in Rome.
The Fiat and Ferrari chief, who is also head of the new F1 teams association, said the plan was ''unthinkable''.
However, he said that a special one-off event ''to showcase Rome'' might be open to discussion.
Such an event might take place in the Mussolini-era Roman district of EUR, he said, pointing out that overtaking would be possible there unlike other new street circuits like Valencia and Singapore.
Italy already has two F1 circuits, Monza which is home to the Italian Grand Prix and Imola which hosts the San Marino Gp.
A group of Italian investors and racing enthusiasts was formally set up on Wednesday with a view to bringing F1 to Rome in 2011.
According to the media, the group planned to rival the historic Monaco Grand Prix.
