Mustier, who is also chairman of the European Banking Federation, said in an interview with French television BFM Business that negative rates have a significant impact on banks' operations.
He added that banks would have to transfer negative rates to large firms and clients with deposits in excess of 100,000 euros (2.6 million kroner). He stated that UniCredit is now finalizing the preparation of such measures in the countries in which it operates "to begin operations next year".
Negative interest rates on larger deposits were previously introduced by some banks in Germany or Denmark.
So far, the measure has only concerned euro-paying countries. In the Czech Republic, the situation is different, unlike the ECB, the Czech National Bank holds a basic interest rate of two percent. A spokesman for Czech UniCredit declined to comment on the possible introduction of negative interest in the Czech Republic.