The European Union (EU) is on the verge of agreeing the details of an emergency plan to rescue Greece's economy, a senior official has said.
EU Commissioner for Economic and Monetary Affairs Olli Rehn said leaders were "about to conclude talks" on the package.
His comments came as European markets rose after two days of sharp falls on concerns about Greece's debt crisis.
The euro also gained ground against the dollar after heavy falls this week.
By mid-afternoon trading, the main stock markets of Paris and Frankfurt had risen by about 1%, while shares in London were up 0.6%.
The Athens stock market had surged more than 7%.
The euro had risen by more than a cent against the dollar, to $1.3271.
Mr Rehn said the European Commission, the European Central Bank and the International Monetary Fund (IMF) had been working hard on a programme that will "reverse the debt spiral of Greece and restore its overall competitiveness".
"I am confident that the talks will be concluded in the next days," he added.
Mr Rehn said any loans to Greece would be conditional on it reducing its debt levels and implementing "structural reform".
The chief architect of Greece's entry into the eurozone has warned of the consequences of failing to act quickly to rescue Greece's debt-laden economy.
In an exclusive interview with the BBC, Yannos Papantoniou, Greece's Economy Minister between 1994 and 2001, urged Europe to act "at very high speed" to rescue the economy.
Greece must be prevented from becoming "the Lehman Brothers of the sovereign debt crisis", he added.
The collapse of investment bank Lehman Brothers in 2008 triggered the global banking crisis and contributed to a worldwide recession.
Some economists are concerned that if Greece's debt crisis is not resolved swiftly, other countries with high borrowing levels could also struggle to repay their debts, as investors lose confidence in some European government bonds.
This week, heightened concerns about the outlook for the Spanish and Portuguese economies led ratings agency Standard & Poor's to downgrade its credit ratings on both economies, while Greece's government debt was given "junk" status.
These actions triggered sharp slides on global stock markets, and forced the euro lower against the dollar.
The eurozone and the IMF have been discussing the terms of a loan package to Greece for a number of weeks.
It is expected to be worth 45bn euros ($59bn; £39bn) in the first year, which it urgently needs in order to refinance its huge public debts.
In recent weeks, international investors have shown they are effectively unwilling to lend Greece money.
Greece's cost of borrowing fell slightly on Thursday morning, reflecting a slight improvement in investors' confidence, but interest rates remain prohibitively high.
Despite pledging to hammer out a deal, German Chancellor Angela Merkel questioned whether Greece should have been allowed into the eurozone in the first place.
She said the decision "may not have been scrutinised closely enough".
Mr Papantoniou blamed Germany for holding up a rescue deal for Greece, saying "forces within German politics" were seeking to push Greece out of the single currency.
He called the current economic situation in Greece "very dangerous", and blamed Europe's slow response to the crisis so far for "sending confused signals to the market".
"We have lost a lot of time," he said. "The reputation of the eurozone has been hurt [and] the stability of the euro has been impaired.
"But even at this late stage it is important for the eurozone to show its determination and effectiveness in dealing [with the crisis].