Ballardini replaced Gian Piero Gasperini in November and managed to finish tenth with the club in the Serie A.
Ballardini’s contract at Genoa was set to expire in the summer of 2012.
“Instead of having another year of contract, from today Ballardini is free,” Preziosi said on Radio Radio.
“I spoke to him by telephone and thanked him for the work he did and the calmness he showed.
“But I won’t divulge the reason for our separation, I don’t think it would be right to do so.”
