A makeshift assistance should be enough to rescue Greece but bigger problems facing Europe would leave the future of the euro currency in question, billionaire investor George Soros said.
Writing in the Financial Times, Soros said what the European Union needed was more intrusive monitoring and institutional arrangements for conditional assistance.
He said a well organized euro bond market was desirable.
"A makeshift assistance should be enough for Greece, but that leaves Spain, Italy, Portugal and Ireland. Together they constitute too large of a portion of euro land to he helped in this way," Soros said.
"The survival of Greece would still leave the future of the euro in question."
Greece's deficit swelled to 12.7 percent of gross domestic product in 2009, way above the EU's cap of 3 percent.
Greece has pledged to reduce its budget deficit to 8.7 percent in 2010.
On Saturday, a magazine reported Germany's finance ministry has sketched out a plan in which countries using the euro currency will provide aid worth between 20 billion euros and 25 billion euros ($27 billion to $33.7 billion) for Greece.
© 2014 Thomson/Reuters. All rights reserved.