Cesare Previti (right) has worked with Mr Berlusconi for decades

Prosecutor Ilda Boccassini said Cesare Previti - Mr Berlusconi's former lawyer and one-time defence minister - had bribed judges to help in a corporate takeover battle in the 1980s.

Mr Berlusconi is also a defendant but is being tried separately because of his governmental duties.

His governing Forza Italia party is moving to make it more difficult for the courts to prosecute him while he is in office - just as Italy is about to assume presidency of the European Union.

Mr Previti told the Italian news agency Ansa the prosecution's claims were "shameful and offensive".

He accused the prosecutor of "throwing mud and poison at [my] years and years of honourable and respectable service as a successful lawyer".

Mr Previti has already been sentenced to 11 years imprisonment in a separate corruption case.

He denies wrongdoing and is appealing against the verdict.

Takeover

Mr Berlusconi has also denied doing anything wrong, contending that he is the victim of persecution by left-wing prosecutors.

The judges ordered a separate trial earlier this month after his lawyers told the court that, yet again, he would not be able to show up for a hearing because he was busy with governmental duties.

Mr Berlusconi has hardly attended his trial, but last month showed up to make a statement to the court.

The decision to order a separate trial was criticised by both prosecutors and defence lawyers.

Mr Berlusconi, a billionaire business magnate, is accused of bribing judges in Rome to sway a ruling on the sale of state-owned food company SME in the 1980s, a decade before he entered politics.

Last month, he told the court that SME was about to be sold off too cheaply, so he intervened after pleas from then-Premier Bettino Craxi, a close friend.