Prosecutors in Palermo, the Sicilian capital, said they have asked a court to decide whether to try Romano, the Italian news agency ANSA reported. A judge refused prosecutors' request to dismiss the charges.
Romano became agriculture minister in March after leaving the UDC, a centrist Catholic party, to join Berlusconi's governing coalition, helping the prime minister survive a vote of confidence. At Romano's swearing in, President Giorgio Napolitano said he had doubts about the wisdom of putting him in the Cabinet.
Salvatore Cuffaro, the former governor of Sicily, began serving a seven-year prison term in January for his dealing with the Mafia. Romano allegedly traded favors to the Mafia for help in elections.
''I don't intend to comment on an act the Palermo prosecutor's office was obliged to make after eight years of investigations and two requests for the case to be dropped,'' Romano said.