Up to 6,000 jobs could be lost if a takeover bid from Italian rival UniCredit is successful, Banco BPM CEO Giuseppe Castagna has warned.
"Cost synergies estimated by the bidder, equal to over a third of Banco BPM's cost base are a point of concern", said Castagna.
The potential job losses were flagged in a letter sent to employees - according to the Italian news agency ANSA.
We are "on the right path for growing on our own, rather than becoming the object of operations that do not take into account the value expressed by our bank today and, even more so, in the near future", Castagna also said in the letter.
He added that Banco BPM has "a strong vocation of closeness to the territories and to SMEs, the backbone of our country".
Castagna's comments echo points made in a statement issued by Banco BPM on Tuesday.
The smaller Italian lender said that the UniCredit bid "does not reflect in any way the profitability and further potential to create value for Banco BPM shareholders".
The statement came after a board meeting on Tuesday, where Banco BPM officials discussed UniCredit's offer from Monday.
The meeting followed a surprise offer from UniCredit in which it announced it would offer 0.175 of its own shares for each share in Banco BPM, valuing the stock at €6.657 each.
Tuesday's statement went on to say that UniCredit's offer was unsolicited, and it raised concerns about the "social impacts" of a merger, as well as UniCredit's expansion in Germany.
UniCredit has been increasing its stake in Germany's Commerzbank, a move facing fierce opposition from Berlin.
A potential takeover would also complicate Banco BPM's pursuit of asset manager Anima Holding as the bank's strategy would likely change.
Earlier this month, Banco BPM launched a €1.6bn offer to buy Anima, seeking to diversify its revenue streams as interest rates fall.