UniCredit said it was increasing to 278 million, from a previous 266 million, the maximum number of new shares to be issued to finance the bid, saying the amount covered any misalignment in share prices due to dividend payments. Based on Thursday's closing price, UniCredit's bid is worth up to 13.29 billion euros.

UniCredit offered to buy the second largest Italian bank Banco BPM for €10bn in late November last year. The acquisition was a counter offer by UniCredit after BPM's bid to buy Anima for €1bn - to boost its asset management fee income amid falling interest rates.

Banco BPM on Tuesday rebuffed concerns raised by suitor UniCredit about its capital reserves, and said it trusted it would be able to apply favourable capital rules to its proposed purchase of fund manager Anima Holding.