European leaders expressed optimism on Friday that Greece would secure a new rescue package worth 130 billion euros ($171 billion) though policymakers admitted urgent work was still needed to get its debt-cutting program back on track.

Luxembourg's Jean-Claude Juncker, who will chair a crunch meeting of euro zone finance ministers on Monday, said efforts to slash Greece's debt from 160 percent of output to a target of 120 percent by 2020 were still far away from fruition.

All the discussions I will have ... until Sunday night will try to move the figure nearer to the target, the head of the Eurogroup told reporters in his home capital.

Earlier, Greek caretaker Prime Minister Lucas Papademos talked to fellow euro zone leaders to persuade Berlin and others to back bailout measures needed to stave off bankruptcy.

German Chancellor Angela Merkel, Italy's Mario Monti and Papademos all voiced optimism about an accord during a three-way conference call, Monti's office said in a statement.

The Greek premier also spoke to Dutch Prime Minister Mark Rutte and state television said he would pursue talks with euro zone partners to create a positive mood in view of Monday's meeting and to dispel doubts that could thwart this agreement.

A brief message by Rutte on his Twitter account noted simply of the call with Papademos: I have pointed out to him that the Greek people should comply with all demands to get a new program.

Rutte's finance minister, Jan Kees de Jager, indicated on Thursday that the whole deal had been close to falling apart earlier in the week, saying that if a planned meeting of the Eurogroup of finance ministers had gone ahead two days ago, he and his German and Finnish counterparts would have voted against granting Greece more aid.

Mutual accusations of brinkmanship between Athens and other euro capitals have soured the atmosphere and strained ties within the single currency union as it faces its toughest challenge since euro notes and coins were introduced in 2002.

Negotiations were put back on track on Thursday when Athens set out the remaining cuts in a 3.3-billion-euro austerity package whose passage through parliament triggered rioting and looting through central Athens last Sunday.

World stocks hit a fresh 6-1/2 month peak on Friday and the euro gained ground as hopes Greece will seal a long-awaited bailout deal at Monday's meeting fuelled risk appetite.

But there are still question marks over whether the bailout will be enough to help Greece back on its feet after a debt crisis that has seen its economy shrink by 16 percent from a 2008 peak, triggering mass unemployment and growing poverty.

The skepticism is especially strong among the 'AAA' states over whether Greece will be able to make it, Germany's Der Spiegel magazine quoted Austrian Finance Minister Maria Fekter as saying of countries with top-notch credit ratings such as Germany, Finland and the Netherlands.

The risk of a Greek insolvency is not off the table.

According to an assessment by the European Commission, the European Central Bank and the IMF, Greek debt will still be around 129 percent of GDP in 2020 - higher even than the 125 percent that most euro zone states would probably accept.

The IMF has said that if the ratio cannot be cut to around 120 percent by 2020, it may not be able to finance the second, 130 billion euro program for Greece. The Fund's own contribution has not yet been settled.

Officials have previously said a target of 125 percent would be acceptable to most euro zone members but further measures will be required to meet even that goal.

SCRAMBLE

Given that, policymakers are scrambling to fill the gap.

Central bank sources told Reuters the ECB was studying whether to allow Greek bonds held in national euro zone central banks' investment portfolios to be subject to the same writedowns which private investors are due to take.

Euro zone central banks hold around 20 billion euros of Greek bonds in their traditional investment portfolios. If they do take losses on those bonds it would provide an immediate lump sum for Athens of around 14 billion euros if they take the same hit as their private counterparts.

One central bank source said it was 50-50 whether the deal would go ahead as an accompaniment to a debt restructuring offer which Greece will offer to private creditors as part of the wider rescue plan. The swap will mean the real value of bonds held by banks and insurers will fall by about 70 percent.

Other ideas to help Athens meet its long-term debt targets include the euro zone cutting the interest rate on its existing bilateral loans to Greece; increasing the current offer of 130 billion euros of government financing; and asking private investors to agree to bigger losses.

The ECB is also expected to forego profits on Greek bonds it holds as a result of its emergency bond-buying program, which could raise something like another 12 billion euros.

Other outstanding issues to be hammered out on Monday include the creation of a ring-fenced escrow account that will be used to pay down Greek debt, and the potentially sensitive issue of how the European Union tightens surveillance of Greek fiscal policy.

Greece needs the funds before 14.5 billion euros of debt repayments fall due on March 20. Yet mistrust is high.

The scenario which we try to achieve is that Greece complies to all necessary measures and to all demands made by the international community in order to have a deal on the total package without a split, de Jager told reporters on Friday.

Certainly if that would not work we have to think of alternative scenarios, he added.

Greece could go to the polls as early as April, raising questions as to whether the new government will stick to the austerity terms.

Conservative leader Antonis Samaras - whom polls tip as the next premier - has said he would pursue the plan while reserving the right to modifications if the economy needs them.

The debt talks have been clouded by growing acrimony between Athens and Berlin, with German Finance Minister Wolfgang Schaeuble likening Greece to a bottomless pit.

Public Order Minister Christos Papoutsis warned on Thursday that the euro zone approach amounted to sheer blackmail.

Earlier, Greece won a public expression of moral support as French Prime Minister Francois Fillon cautioned Europe that it should not play with the default of Greece.

The Greeks have promised very important reforms, he told RTL radio. The Europeans now have to keep their commitments. ($1 = 0.7597 euros)

(Additional reporting by Michele Sinner in Luxembourg and Berlin, Frankfurt and Brussels bureaux; Writing by Mark John, editing by Mike Peacock)

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