International lenders have agreed new steps to cut Greece's debt pile further but it still has to fill a 10 billion euro ($13 billion) gap to gain the IMF's approval for its next tranche of aid, a senior Greek government official said on Friday.
The International Monetary Fund has agreed to deem the country's debt viable if it falls to 124 percent of GDP in 2020, giving ground on its earlier target of 120 percent, the official said on condition of anonymity.
"The euro group has already agreed on measures to reduce Greek debt to 130 percent of GDP in 2020, so that leaves a gap of 5-6 percentage points of GDP to be covered -- about 10 billion euros," he added.
The official did not disclose what measures had been identified that would reduce the lenders estimate of public debt in 2020 from a previous 144 percent of GDP.
Another senior source involved in the negotiations confirmed that the IMF would now accept 124 percent as a target but said that to say the remaining gap only amounted to 10 billion euros was much too optimistic.
According to current government projections, Greek debt is seen at 340.6 billion euros, or 175.6 percent of GDP at the end of 2012. It is expected to peak at 357.7 billion euros, almost 191 percent, in 2015.
Greece's international lenders failed earlier this week to agree how to get the country's debt down to a sustainable level and will have a third go at resolving their most intractable problem on Monday.
According to a document circulated at that meeting, Greece's debt cannot be cut to 120 percent of GDP by 2020, unless euro zone member states write off a portion of their loans to Greece, which Germany has consistently said would be illegal.
The document prepared for the meeting of euro zone finance ministers and seen by Reuters spelled out several options, including using about 10 billion euros to buy back bonds at between 30 and 35 cents in the euro.
There are also proposals to reduce the interest rate on loans already extended by euro zone countries to Greece, to impose a moratorium on interest payments and lengthen the maturities on loans, all of which would cut the debt burden.
($1 = 0.7761 euros)
(Reporting by Harry Papachristou, editing by Patrick Graham/Mike Peacock)