The IMF urged the eurozone to move quickly Wednesday to halt contagion from the continent's public debt crisis, by granting embattled banks access to an emergency fund.
The International Monetary Fund suggested that authorities could expand the use of the European Financial Stability Facility, originally designed to bail out countries, to directly aid the banks.
"Some European banks urgently need to bolster their capital levels," the IMF said in its semiannual Global Financial Stability Report.
"In current market conditions, however, this may not always be possible, so public backstops, first at the national level and ultimately through the European Financial Stability Facility should be used to provide capital to banks as needed," the IMF said.
Launched in May 2010, the EFSF was intended to help eurozone economies in trouble. In July, leaders agreed a set of reforms to expand the scope of the EFSF, including allowing it to recapitalize banks through loans to governments.
But that plan requires parliamentary ratification by the zone's 17 member nations. To date, only the parliaments of France, Belgium, Italy and Luxembourg have approved.
"Some banks may need to do very little, but others -- especially those heavily reliant on wholesale funding and exposed to riskier public debt -- may need more capital," Jose Vinals, head of the IMF's monetary and capital markets department, said at a news conference.
The IMF estimated the eurozone debt crisis has piled up 300 billion euros in sovereign credit risk for banks in the European Union in the past two years.
Of the total, 60 billion euros comes from the sovereign debt in Greece, 20 billion euros from Ireland and Portugal, and 120 billion euros from Belgium, Spain and Italy.
The IMF estimated another 100 billion euros in sovereign credit risk were linked to the banks of those six countries.
Considering the magnitude of these risks, and that "markets are likely to remain volatile," the IMF warned that banks may find it impossible to access capital on the markets.
Many analysts say that Italy or Spain could be the next dominoes to fall in the escalating eurozone crisis, which so far has witnessed massive bailouts for debt-ravaged Greece, Ireland and Portugal.
On Wednesday, Lloyd's of London said it had slashed its exposure to European government debt and pulled cash out of some of the region's banks amid the deepening eurozone crisis.
"Given the uncertainty around the eurozone, it's only natural that we would seek to reduce any potential downside risk," Lloyd's Finance Director Luke Savage told Dow Jones Newswires.
"As a result, we're not holding government debt of any peripheral EU country and have sought to reduce our exposure to banks in these countries."
The IMF devoted a large section in the report to Italy, the third-largest economy in the eurozone that holds the second-largest largest debt pile, of more than 1.9 trillion euros.
"Given the systemic size of the bond markets in Italy and the sovereign funding needs there, these risks have become key drivers of market conditions, increasing the potential for spillovers across different asset markets," the IMF said.
Italy's debt "remains highly sensitive to a rise in funding costs."
On Tuesday, the IMF's chief economist, Olivier Blanchard, called on the eurozone to be ready to help Italy if "the markets start believing that Italy's debt is not sustainable."