Pierluigi Collina, the famous bald official who took charge of the 2002 World Cup final between Brazil and Germany, has called time on his career after quitting the Italian Association of Referees (AIA) today.

Collina had been accused by the AIA of a conflict of interest after he accepted an €800,000 per year sponsorship deal from carmakers Opel, who also back AC Milan.

"After 28 years I've decided to hand in my resignation to AIA," Collina was quoted as saying by the Italian news agency ANSA.

"I can't help it. People must believe in a referee. In the end, we have all lost out," he told a news conference in his home town of Viareggio.

Collina's decision to quit brought to an end a career that turned him into one of the most recognisable figures in world football.

With his loping stride and pop-eyed stare, the Italian enjoyed a reputation for quick, accurate decision-making.

Collina possessed an authoritarian streak that won the respect of players, coaches and fans.

Had it not been for the intervention of the Italian Football Federation (FIGC) at the end of last season, Collina would already have been in retirement.

He turned 45 in February, the age at which referees are obliged to hang up their whistles, but the FIGC changed the rules to give him one more year in the job.

It was a recognition of his special talent.

Five times voted World Referee of the Year, Collina's finest hour came when he took charge of the 2002 World Cup final.

He also directed a string of high-profile matches like Manchester United's dramatic 2-1 win over Bayern Munich in the 1999 Champions League final and England's 5-1 hammering of Germany in a World Cup qualifier in 2001.

Collina enjoyed the perks of fame, including modelling designer clothes, advertising fried octopus and cheese and even appearing in cartoon form in the video to the George Michael single Shoot the Dog.

His book, The Rules of the Game, became one of the best-selling to be written about the referee's craft.

What now lies ahead for the Italian is uncertain. The vice-chairman of the English Football Association, David Dein, has spoken in the past about luring him to work in the Premier League.

Today, however, a visibly emotional Collina gave no hint of his future plans and appeared stung that his spotless career should end with his credibility being brought into doubt.