European leaders are poised for the second straight year to approve a financial bailout for Greece, but even then the debt-ridden country may temporarily default on some of its previous loans.

Officials from the continent’s 17 nations that employ the common euro currency met in Brussels Thursday to discuss Greece’s financial woes. But their broader goal was to keep Europe’s debt contagion from spreading to the much larger economies in Spain and Italy, whose governments also are struggling to control spending and increasing deficits.

In the last year, Greece — and later, Ireland and Portugal — were forced to secure international financial assistance from their European neighbors and the International Monetary Fund. But Greece, even after adopting austerity measures to cut spending and raise taxes, says it needs another bailout of about the same size as last year’s $156 billion figure.

The financial problems in Athens could mean that the government will not be able to meet all its current obligations. The continent’s officials, including Eurogroup President Jean-Claude Juncker and others, said Greece may incur what they called a “selective default” on their current obligations.

That could mean that Greece might miss a payment to bond holders on some loans while continuing to make payments on others. Or it could exchange old debt for new loans on terms that would leave creditors worse off.

Hours before the summit started, the leaders of France and Germany, Europe’s two largest economies, reached an agreement on helping Athens. French President Nicolas Sarkozy met with German Chancellor Angela Merkel in Berlin before they headed to Brussels.

Mrs. Merkel told reporters she expected that officials “will be able to seal a new Greece program.”

With news of the likelihood of selective Greek defaults, the value of the euro slumped against the dollar, falling from $1.43 early Thursday to $1.415.