It also suppressed voting rights of Espirito Santo Financial Group, BES's largest shareholder which holds its 20 percent stake on behalf of the bank's founding family. It named PWC to lead a supervision commission at BES until shareholders name new internal auditing officials.

The central bank wants BES to carry out a capital increase soon using "market solutions", but a public recapitalisation line remains a backup option guaranteeing the bank's solidity even after the massive loss, the Bank of Portugal said in a statement.

It added that "all the necessary conditions are in place for the bank to continue its activities and for the full protection of the rights of depositors".

(Reporting By Andrei Khalip; Editing by Laura Noonan)