Former talent scout Lele Mora, Lombardy regional councilor and Berlusconi's former dental hygienist Nicole Minetti and retired television anchor Emilio Fede have been charged with inducing and favoring prostitution, including underage prostitution, at alleged sex parties hosted by Berlusconi at his villa at Arcore near Milan, Italy's ANSA news agency reported.
Mora and Minetti were present in court Friday.
In a separate trial, Berlusconi is accused of paying to have sex with Karima "Ruby" El Mahroug, a Moroccan-born belly dancer who was underage at the time, as well as allegedly coercing police into releasing her after an unrelated theft claim to hush up the allegation.
All defendants have pleaded innocent.
After the trial Friday, Mora said Berlusconi was innocent and that the so-called "bunga bunga" sex parties were nothing more than a "joke."
"At Arcore we ate and had a good time," Mora said.