The talks come after two days of negotiations between EU finance ministers ended without a breakthrough and as Athens was again denied the next eight billion euro ($10.7 billion) tranche of bailout cash it needs to avoid default.
In the Greek capital, civil servants staged another 24-hour walkout to protest against a government plan to sideline 30,000 staffers to reduce the bloated public deficit in return for a bankruptcy-saving EU-IMF loan.
Fears that the debt crisis could trigger a new financial sector collapse have sent global markets into freefall, but comments by the European Commission that it planned a coordinated bid to recapitalise lenders lifted US shares.
The respite was shortlived, however, with Asian traders more sceptical after news that Franco-Belgian bank Dexia had been broken up and Italy's debt rating had been cut, with Tokyo and Seoul both falling.
As the two-days crisis talks wrapped up Tuesday, EU officials demanded Greece make more sacrifices and warned banks may have to shoulder more losses as part of the resolution of the debt crisis.
"I am not pretending that by the end of the day we had a solution to the eurozone crisis, much to my frustration," British Chancellor George Osborne told Sky News after returning from Tuesday's meeting in Luxembourg.
"But I think we did take some steps forward ... We need to reflect on the reality of the situation in the eurozone and account for the reality of sovereign risk, which requires more capital in some eurozone banks."
European commissioner for economic affairs Olli Rehn told the Financial Times that a unified approach to the crisis was required.
"There is an increasingly shared view that we need a concerted, coordinated approach in Europe while many of the elements are done in the member states," he told the paper.
"Capital positions of European banks must be reinforced to provide additional safety margins and thus reduce uncertainty," Rehn said.
On Tuesday, Dexia's shares plunged 37 per cent before French and Belgian regulators stepped in to guarantee its depositors and creditors.
French Finance Minister Francois Baroin compared the guarantees to the 6.4-billion-euro bailout of Dexia in 2008, when it was hit by the US sub-prime loan crisis.
Ratings agency Moody's downgraded Italy's government rating from Aa2 to A2 with a negative outlook, citing risks for the financing of long-term debt and slow economic growth.
And in a separate report Moody's warned that the market pressure on European sovereign debt was not about to let up, with the prospect of weak growth in the eurozone likely to prevent governments from reducing their deficits.
"There has been a profound loss of confidence in certain European sovereign debt markets, and Moody's considers that this extremely weak market sentiment will likely persist," it said in an analysis published late Tuesday.
"It is no longer a temporary problem that might be addressed through liquidity support, and several euro-area governments are increasingly affected by the loss of confidence."
The worry over how banks would be hit grew when Luxembourg premier Jean-Claude Juncker warned them to expect greater losses on their Greek debt than the 21 per cent "haircut" agreed in July.
German Finance Minister Wolfgang Schaeuble confirmed that bondholders might have to take a bigger writedown, underlining that banks would then take a bigger hit.
Many European banks -- notably French banks -- have extensive holdings of Greek sovereign debt, and are expected to need substantial capital support in the event of a default.
With Juncker warning that Athens could wait until November to collect its next rescue package handout, Greek Finance Minister Evengelos Venizelos suggested his country was being made a "scapegoat" for eurozone debt troubles.
The bad news hit stock markets and the euro Tuesday. London's FTSE-100 fell 2.58 per cent; the DAX tumbled 2.98 per cent and the CAC-40 shed 2.61 per cent.
But the European Commission comments of a possible concerted approach to protect European banks boosted US stocks at the end of trade.
The European currency on Tuesday hit a nine month low against the dollar at $1.3146, and a 10-year low on the yen, 100.76 yen.
And in Asian trade the euro edged down and stood at $1.3315 against $1.3338 late Tuesday in New York.
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