A Milan court yesterday sentenced him to one year in jail, although he is unlikely to be put behind bars during a possible appeal. The verdict will have no impact on Berlusconi's eligibility to participate in a new government. His centre-right coalition finished third in parliamentary elections that saw no clear winner. Talks on forming a new government are expected to begin on March 20.
The charge relates to the 2005 publication of a wire-tapped call that was part of an investigation into a failed bid to take over a bank.
Berlusconi's brother Paolo was convicted of the same charge and sentenced to two years and three months. Paolo Berlusconi is publisher of the Milan newspaper il Giornale, which published the transcript of the conversation.
Silvio Berlusconi's defence team had accused the court of seeking a speedy verdict for political impact.
Wiretapped conversations are widely published in Italian media, despite the risks of prosecution.
In a potentially more damaging case, a verdict is also nearing in Silvio Berlusconi's appeals trial on a conviction of tax fraud.
Prosecutors have demanded the court uphold the October conviction and four-year sentence. They also are seeking a five-year ban from public office.
Silvio Berlusconi is also on trial in Milan for allegedly paying an under-age teenager for sex and lying to cover it up, with a verdict likely this month. And prosecutors in Naples are investigating him for corruption for allegedly paying an opposition lawmaker €3 million (£2.6m) to join his party.