Euro zone agrees new bank rules
The deal foresees banks with assets of 30 billion euros, or larger than one-fifth of their country's economic output, being supervised by the ECB rather than national supervisors.
France's Moscovici said that would put more than 150 banks under the ECB's watch.
Critically, it also gives the ECB authority to widen its authority to smaller banks if problems arise.
That will satisfy Germany, which wanted to maintain primary oversight of its savings and cooperative banks, nearly all of which will not fall under direct surveillance from Frankfurt unless they run into problems.
Talks ran into the early hours of yesterday because ministers needed to resolve a potential conflict of interest between the ECB's roles as supervisor and as guardian of monetary policy.
Such a conflict could arise if, for example, the ECB were to keep interest rates low to prop up banks.
They agreed to introduce a mediation panel to resolve disputes with national supervisors, a move Germany was satisfied would act as a counterbalance to the authority of the European Central Bank's Governing Council.
A steering committee will guide the work of the supervisory body, which in turn is answerable to the ECB's Governing Council. That leaves the final say with the ECB.
Reaching a deal also required granting concessions to Britain, a member of the European Union that does not use the euro, which worried that the ECB would undermine its autonomy in policing the City of London, Europe's top financial centre.
London had asked for changes to the system of voting when regulators from across the European Union meet to flesh out EU law, such as defining the capital reserves that banks can use as buffers.
Those regulators meet under the umbrella of the European Banking Authority, but London had been concerned that countries in the euro zone would force through rules in their favour.
EU ministers agreed that a double vote would now take place - one for those in the banking union and another for non-euro countries outside - before decisions on EU regulation are taken.
Meanwhile, Euro zone finance ministers and the International Monetary Fund have agreed to release €49.1 billion in aid to Greece by the end of March, with most of that sum flowing immediately.
"Money will be flowing to Greece as early as next week," Eurogroup chairman Jean-Claude Juncker told a news conference after a meeting of ministers from the single currency bloc. "We are convinced the programme is back on a sound track."
A Eurogroup statement said €34.3 billion would be paid out in the coming days and the remainder in the first quarter of 2013.
Agreement to release the funds hinged on the success of a debt buyback launched by Greece last week, which will enable Athens to retire nearly €20 billion in bonds repurchased at a third of their face value from private holders.
Mr Juncker said he was not sure that additional measures would be needed to reach an agreed goal to bring Greece's debt down to 124 per cent of gross domestic product (GDP) by 2020, but the bloc stood ready to take new steps if necessary.