TURIN, Italy (Reuters) - Thousands thronged Turin's cobbled streets Sunday for the funeral of Fiat king Gianni Agnelli, after many waited overnight to catch a glimpse of the billionaire industrialist's coffin.

Waves of applause greeted the hearse of Agnelli, who had symbolized the glamour and promise of Italy's post-war regeneration, mingling with the world's elite from John F. Kennedy to Muammar Gaddafi.

"He was the center of everyone's attention for half a century for his prestige and also for his qualities as a great entrepreneur," Turin's Cardinal Severino Poletto said in the northern city's cathedral, whose congregation included faces from Italy's political, business and sporting elite.

Italian Prime Minister Silvio Berlusconi and President Carlo Azeglio Ciampi were greeted at the doors of the flower-decked cathedral by Umberto Agnelli, in line to take over the chairmanship of the Fiat empire his brother built.

Gianni Agnelli oversaw the growth of Fiat from a family car company into an empire that stretched from racing cars to vineyards to newspapers.

Dubbed "the lawyer," he was best known abroad for growing Fiat into a global conglomerate and steering it through business crises, union unrest and terror attacks over 40 years.

For Italians he was simply a Prince Charming. Many of the tens of thousands who waited overnight in the cold to see his coffin at Fiat's Lingotto factory said it was his great charisma they had come to honor.

A billionaire with a sense of style, Agnelli's patrician fashion quirks -- such as wearing his wristwatch on the outside of his shirt cuff -- were copied by a nation of young men.

And in a land of passionate sports followers, Agnelli was the number one fan and owner of the mighty Juventus soccer club and of Formula One champions Ferrari.

Fiat's glory years turned the sleepy city of Turin into a boom town, whose population mushroomed as thousands fled Italy's impoverished south in search of a better life.