European Union finance ministers agreed an emergency loan package on Monday that with IMF support could reach 750 billion euros ($1,000 billion) to prevent a sovereign debt crisis spreading through the euro zone.
The European Central Bank also announced steps to contain Greece's debt crisis, saying it would buy euro zone government and private debt and abandoning resistance to full-scale bond purchases.
"The fiscal efforts of the EU member states, the financial assistance by the (European) Commission and by the member states (and) actions taken today by the ECB prove we shall defend the euro whatever it takes," EU Monetary Affairs Commissioner Olli Rehn told a news conference after more than 11 hours of talks.
The EU finance ministers announced a package consisting of a special-purpose vehicle via which euro area states would guarantee on a pro rata basis up to 440 billion euros, plus a European instrument worth 60 billion euros.
Clarifying earlier statements, they said the International Monetary Fund was expected to make a contribution of about 250 billion euros.
Economists have estimated that if Portugal, Ireland and Spain eventually required similar three-year bailouts to that received by Greece, the total cost could be 500 billion euros.
"This is not only about Greece but about stability in Europe as a whole," Rehn said.
The measures dwarf any previous attempts by the 27-country EU or the 16-state single-currency group to calm what Swedish Finance Minister Anders Borg described as the "wolfpack" of the financial markets.
The moves were coordinated by the European financial institutions and involved discussion among the Group of Seven finance ministers, showing the global concern that problems that began in Greece could cause havoc on world financial markets.
Greece, with a budget deficit of 13.6-14.1 percent of gross domestic product in 2009 and debt of more than 115 percent of GDP, already has secured a 110-billion-euro, three-year loan package from the 16-country euro zone and the IMF.
The size of the deal agreed on Sunday, two days after a summit of euro zone leaders, reflected the growing sense of urgency in the EU and around the world that a sovereign debt crisis could rapidly sweep global markets.
The ministers also called for budget consolidation, sustainable finances, improved economic growth and closer economic coordination. Plans for fiscal consolidation and structural reforms would be accelerated where needed, they said.
