ROME (Reuters) - Ferrari president Luca di Montezemolo said on Wednesday that Max Mosley should quit as chief of motor racing's world governing body over his involvement in a sex scandal.

"I think that he should realize that sometimes it is necessary to say to yourself I have to leave for reasons of credibility," Montezemolo told the ANSA news agency.

Mosley was given a strong vote of confidence to remain as president on Tuesday, gaining 103 votes to 55 against in a secret ballot at an extraordinary meeting of the International Automobile Federation (FIA) general assembly in Paris.

The 68-year-old Briton has ignored calls to quit since March when the tabloid News of the World newspaper published details and photographs of his involvement in what was described as a Nazi-style sado-masochistic orgy with prostitutes.

The FIA president, whose father Oswald was the founder of the pre-World War Two British Union of Fascists, has denied any Nazi connotations to the scandal and is taking legal action against the News of the World for invasion of privacy.

(Reporting by Paul Virgo, editing by Justin Palmer)