Global markets rallied, though some only briefly, after news that about €45 billion ($86 billion) will be made available to Greece by her eurozone partners and the International Monetary Fund.
The loan amounts to almost a fifth of the country's gross domestic product.
Greece's Prime Minister, George Papandreou, said the aid package sent "a clear message that nobody can play with our common currency and our common fate".
The euro jumped sharply against the dollar and sterling.
The costs of insuring Greek sovereign debt - credit default swap premiums - also fell from about 400 basis points to 350.
There was a similar easing in Greek government bond yields with the return on 10-year Greek bonds down from 7 per cent to 6.65 per cent.
Equity markets from the FTSE 100 to the Dow Jones registered their relief, though the gains in London were pared back by the time markets closed.
Germany will provide the bulk of the funding through bilateral loans. Some US$30 billion ($42 billion) will be available and a further €15 billion will be left to the IMF
At about 5 per cent, the cost of funding will be below the punitive rates demanded by investors of up to 7 per cent. Analysts said the money should last until the end of the year.
However, few believe the crisis has been resolved. Fitch, the ratings agency which helped to prompt the latest twist in the crisis by downgrading Greek debt to BBB- status, one notch above junk status, spoke for the more sceptical.
Its analyst, Paul Rawkins, warned: "We still have concerns about the prospects of sustaining fiscal consolidation. It doesn't change the action we took."
An early test of the credibility of the deal will come today when Greece tries to roll over about €1.2 billion in short-term debt.
Dominique Strauss-Kahn, the managing director of the IMF, said: "The only effective remedy that remains is deflation. And this is exactly what the European Commission has correctly recommended."