Berlusconi is charged with paying $600,000 to David Mills, estranged husband of Tessa Jowell, who served in the Labor Cabinet. The former prime minister has accused the court and prosecutors of a politically motivated prosecution.
At Wednesday's hearing, Prosecutor Fabio DePasquale said there is no doubt of Berlusconi's guilt, the Italian news agency ANSA reported. The sentence is scheduled to be delivered later this month.
The sentence could be moot because of Italy's statute of limitations laws.
Berlusconi, who resigned as prime minister last year, is entangled in three other criminal cases.
"The judicial persecution carried out against Silvio Berlusconi is so obvious, striking and persistent that it is a political and moral problem that no one can ignore," Sandro Bondi, a leader in Berlusconi's People of Freedom Party and minister of culture in his Cabinet, said.