MILAN, Dec 19 (Reuters) - A key investor in ailing Italian bank Monte dei Paschi di Siena's privately funded rescue plan is unhappy with one crucial aspect of the deal, a disagreement that could sink the entire plan if not resolved, the bank said on Monday.
Monte dei Paschi said the investor, banking industry bailout fund Atlante, had expressed "deep reservations" in a letter dated Dec. 17 over the terms of a bridge loan accord. The loan is an essential part of the bank's plan to sell 28 billion euros ($29.2 billion) in bad loans and raise 5 billion in capital.
It said it was trying to resolve the issue with Atlante.
"If issues raised by (Atlante's manager) Quaestio cannot be solved, the operation could not be concluded by Dec. 31, 2016 as requested by the European Central Bank," the bank said in a statement. ($1 = 0.9584 euros) (Reporting by Valentina Za; Editing by Mark Bendeich)