The 26-year-old has failed to dislodge first-choice stopper Joe Hart at the Etihad Stadium, and is eager for regular first-team football.
Citizens boss Roberto Mancini has used Pantilimon sparingly since signing him from Politehnica Timişoara in 2012, though he has given him a run-out in the club's successful FA Cup campaign this year.
The 6ft 8in stopper will retain his place for next month's Wembley final showdown against Wigan Athletic, in what could be his last appearance for Manchester City, should he leave the club at the end of the season.
Numerous clubs in Serie 'A' are believed to be monitoring Pantilimon's situation at the reigning Premier League champions, though Fiorentina are the only party who are confirmed admirers.
His departure will almost certainly force Mancini back into the transfer market to find a replacement back-up goalkeeper to provide competition for undisputed number one, Hart.