Former Italian prime minister Silvio Berlusconi was found guilty on corruption charges Wednesday by a Naples court, which said he bribed a senator to help weaken the party of his main political opponent, Romano Prodi.

In the culmination of the trial that began in February 2014, Berlusconi was found guilty and sentenced to three years in prison for paying then-senator for Italy of Values Sergio De Gregorio 3 million euros to give support to Berlusconi's party, Forza Italia, from 2006 to 2008. De Gregorio took a plea bargain and admitted to taking the money while he was serving as senator, and was handed a 20-month sentence.

Prodi is the only politician who has defeated Berlusconi in prime ministerial elections — in 1996 and 2006. His second victory relied on a slim majority in the Senate, and eventually collapsed in 2008.

Despite the conviction, Berlusconi won't serve his three-year sentence, as the statute of limitations in the case will end before the appeals process ends. Under Italian law, two levels of appeals must be completed before defendants begin serving a sentence. The process could take years, and the statute of limitations will expire in a few months.

The defense argued during the trial there was no proof of any deal between De Gregorio and Berlusconi. "It's a verdict that we contend is shockingly unfair and unjustified," one of his lawyers, Niccolo Ghedini, said after the conviction Wednesday. Berlusconi himself was not in court.

Valter Lavitola, who prosecutors alleged was the go-between for Berlusconi and De Gregorio, was also convicted and given a three-year sentence.

Berlusconi has previously been at the center of numerous corruption allegations. In 2013, he was found guilty of tax fraud and sentenced to four years in prison — though the sentence was reduced to doing part-time community service, which he recently completed.

That was the first decisive conviction for Berlusconi, and led to his expulsion from the Senate and a ban on holding public office for two years. Despite this, he still holds considerable sway and influence over Forza Italia and remains one of the country's richest men.

Berlusconi has also faced charges of soliciting sex from an underage prostitute, corruption, and working with the mafia. Prosecutors are now probing allegations that Berlusconi or his aides may have paid off witnesses in the sex case.