Proceedings were immediately thrown into doubt when prosecution lawyers demanded that the new presiding judge should step down for having discussed the case in newspaper interviews.
The panel of three judges, all new to the high-profile case, went into recess to discuss the request.
Berlusconi himself was not in court.
The resumption of the trial comes at a critical time for the prime minister, who is grappling with the Iraq hostage crisis and seeking to bolster his political fortunes at European Parliamentary elections in June.
Berlusconi stands accused of bribing judges to prevent the 1980s sale of a state-owned food chain, called SME, to a rival businessman. He denies the charges and says he is the victim of a politically motivated witch-hunt.
The original trial was put on hold last June when parliament granted him immunity from prosecution. The controversial law was later overturned by Italy's top court which ruled it was unconstitutional.
In the meantime, proceedings against others accused in the same case continued.
In a ruling in November which could favour the prime minister, Cesare Previti, a former Berlusconi lawyer, was acquitted of the charge in the SME case.
However, he was simultaneously convicted of another bribery charge tied to his dealings with Berlusconi's business empire and sentenced to five years in jail. He is appealing the verdict.