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,

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.

Commerzbank on Wednesday defined UniCredit's approach for a potential tie-up as "hostile", and said there had been no discussion of it with the Italian bank in the past two years, despite UniCredit CEO Andrea Orcel saying there had.

Commerzbank AG stepped up its rhetoric against the approach from UniCredit SpA, further complicating the situation for the Italian lender.Most Read from BloombergTexas HOA Charged With Discrimination

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.