Prosecutor Ilda Boccassini also requested that Berlusconi be banned for life from holding public office if convicted.
Berlusconi is accused of engaging in sex with an underage prostitute and allegedly using his influence to have her released from a police station after an unrelated theft charge, the Italian news agency ANSA reported Monday.
Berlusconi denies he and the girl engaged in sex, and claims the case is another example of alleged left-wing prosecutors attempting to hound him from office, ANSA said.
Prosecutors told the court Monday there was "no doubt" the girl was paid for sex and was an underage prostitute.
Berlusconi is accused of paying for sex with Karima El Mahroug, a Moroccan stripper with the stage name "Ruby Heartstealer" before she was 18 and of abusing his power to hide the affair.
Prosecutors have produced phone records indicating El Mahroug stayed at Berlusconi's villa several times in April and May of 2010, when she was 17, ANSA reported.
"We have no doubt that Ruby prostituted herself," Boccassini said.
El Mahroug and Berlusconi both deny they had sex while she was underage during sex parties at his villa.
Concerning the abuse of power charge, Berlusconi said he intervened because he genuinely believed El Mahroug when she said she was a relative of ousted Egyptian President Hosni Mubarak.
Prosecutors said Berlusconi had sex with 33 other alleged prostitutes at his villa over several evenings, ANSA said. Berlusconi called his parties innocent and "elegant" affairs.