Commerzbank reiterated on Friday that it will not meet with UniCredit for formal discussions until it receives a specific proposal from the Italian bank, which has ruffled feathers in Berlin with its interest in a merger.

Commerzbank chief Bettina Orlopp shot down an invitation from Andrea Orcel to hold informal talks about a potential tie-up with UniCredit, and has instead insisted on receiving a written proposal before engaging, according to people familiar with the situation.

Germany's Commerzbank has demanded a formal written proposal amid a potential takeover by Italian bank UniCredit. "We have always signalled our willingness to talk and would examine a proposal from UniCredit in the interests of all stakeholders,

UniCredit SpA Chief Executive Officer Andrea Orcel said he was surprised by the backlash in Germany over his efforts to acquire Commerzbank AG, saying his bank was invited to bid and communicated with all sides.