The European Banking Authority said on Wednesday the bloc's banks need to raise 106 billion euros of capital to meet a new minimum core tier 1 capital ratio of 9 percent by the end of June 2012.
The measure is part of broader efforts being thrashed out by euro zone leaders in Brussels to restore confidence and stability to the bloc's markets and economy.
Greek banks will need an extra 30 billion euros of extra capital, the EBA said in a statement, although this is covered by an existing programme of aid.
The capital raised will have to be of the highest quality although new issuance of very strong convertible capital would be accepted, the watchdog added.
Banks are expected to withhold dividends and bonuses as part of their efforts to meet the new requirements which exceed the 7 percent minimum world leaders have agreed to phase in from 2013.
(Reporting by Huw Jones and Steve Slater)