Deputy finance ministers and central bankers of the 16 countries sharing the European single currency decided that any emergency loans would be made on terms almost identical to standard IMF bailouts if Greece needed them, an EU source said.
But the news brought only momentary relief on credit markets because Fitch Ratings cut Greece's credit rating to BBB- and signaled further downgrades are possible, citing intensifying fiscal challenges in the debt-plagued country.
New figures published on Friday highlighted a deepening recession that will further aggravate those problems as the government continued to resist market pressure to seek outside help with its debt crisis.
After investors dumped Greek assets this week due to growing doubts over the euro zone/IMF rescue plan, the risk premium on Greek bonds compared to benchmark German bunds briefly dipped below 400 basis points on news of the Brussels deal.
First details of the Brussels agreement suggested Germany and the Netherlands had eased their insistence that rescue loans to Greece be at close to current punitive market rates.
The EU source said that loans terms would be close to IMF terms on three-year credits of 300 basis points above the concessionary Special Drawing Rights rate (151 basis points), plus a 50 bps service charge.
That would be a rate of 5.01 percent, higher than Greece had hoped but well below the current market rate of 7.3 percent, according to Tradeweb data.
The European Commission and the European Central Bank would propose the amount and maturity of the loans depending on Greece's funding needs, the source said. Any disbursement would require the unanimous agreement of the 16-nation euro zone.