But the International Monetary Fund and European Union are demanding further austerity measures as a price for the bailout, according to a top Greek labor union official.

Greece will be required to cut civil servants' salaries, freeze their pay increases, reduce their pension payments, change tax rates and increase the value-added tax consumers pay on purchases, according to Ilias Iliopoulos, the general secretary of the public sector union ADEDY.

The International Monetary Fund did not respond immediately to a request for confirmation of the value of the package. Its head, Dominique Strauss-Kahn, said on April 28 the agency did not release information about deals in the works until they were done.

"Until we reach this point there is no precise information to give because the information doesn't exist," he said.

Greece's credit rating has been slashed twice in the past two weeks -- most recently being downgraded to "junk" -- raising fears for the euro currency used by 16 nations across Europe.

Markets worldwide tumbled when Standard & Poor's downgraded Greece earlier this week. It's the first European country to fall below investment grade.