Italy's oldest bank, the only Italian lender to be bailed out during the financial crisis, is saddled with problematic loans equal to more than a fifth of its total client loans.
Other Italian banks informed of the ECB's bad-loan monitoring included Banco Popolare and Banca Popolare di Milano, two cooperative lenders currently involved in tie-up talks to improve efficiency.
"The ECB has informed the bank it has started an assessment on NPLs... as part of the ongoing supervision process which will involve... other Italian and European banks," Popolare di Milano said in a statement.
The assessment will take place some time between January and February, Banco Popolare said.
Lenders who had not received any notification from the ECB on bad loan assessment included Italy's No. 1 retail bank Intesa Sanpaolo ,top merchant bank Mediobanca and UBI Banca.
Earlier this month, JPMorgan said Italian banks should be avoided partly because credit problems limited a recovery in provisions.