Greek Prime Minister Lucas Papademos has said party leaders have failed to reach a full agreement on all measures demanded by the Troika.
Mr Papdemos said that one remaining issue requires further work and it will be discussed with the EC, ECB and IMF overnight.
He did not specify the issue that remained unresolved after tonight's seven-hour meeting in Athens.
Greek far-right leader George Karatzaferis said the three leaders had spent the bulk of the meeting discussing the issue of supplementary pensions.
The politicians finally met after repeated delays that have prompted warnings that the euro can live without Greece.
One deadline after another has passed without the leaders making up their minds on terms for the new €130 billion rescue, which Greece must receive to avoid going bankrupt next month when big debt repayments are due.
The 17 finance ministers from the eurozone are ready to meet in Brussels tomorrow evening to sign-off on any deal.
The deal would then go back to the Greek Parliament for a final vote this weekend.
President of the Eurogroup, Jean-Claude Juncker, said earlier that he had seen progress in talks between Greece and private creditors to slash €100 billion in debt.
He added that he hoped "to get a clear picture of the situation by tomorrow morning".
ECB "will take some Greek bond losses"
A report in the Wall Street Journal has said the ECB will participate in a sharp writedown of Greece's debt currently under negotiation in Athens.
The newspaper said the bank, one of Greece's biggest creditors, has "agreed to exchange the government bonds it purchased in the secondary market last year at a price below face value, provided the debt restructuring talks have a successful outcome".
According to the newspaper, the ECB would give up its interest payments, or coupons, on Greek debt bought in a controversial bond buying programme launched in the early days of the euro zone debt crisis.
The ECB bought the bonds beginning in May 2010 in an effort to push down borrowing prices for Athens. The effort failed and Greece has in effect been locked out of the bond markets ever since.
Greece's creditors are being asked to write off about half of the €200 billion worth of government debt they hold to cut the country's total debt burden down to a sustainable level of 120% of GDP in 2020 from 160% at present.
