Key policy-makers from Europe and the United States thrashed out ideas for pulling the eurozone out of its debt crisis at the Davos forum on Friday, days ahead of a key European summit. While cloistered in a snow-bound conference centre high in the Swiss Alps, the global political and business elite had one eye on Greece, hoping that a long-awaited deal to write down its debt might at last fall into place. Greek Prime Minister Lucas Papademos is in talks with banks and insurers on a voluntary exchange of bonds that would wipe 100 billion euros ($130 billion) off the country\'s debt of 350 billion euros. The deal under discussion would see private creditors take a \"haircut\" of at least 50 percent on 200 billion euros in debt. Previous talks stalled over the amount of interest to be paid on the remaining debt. Any failure to strike a deal could trigger a messy default, which would be an economic disaster for Greece itself, a threat to banks holding too much sovereign debt and pile on the pressure on other eurozone state. World markets and delegates in Davos have begun to show signs of cautious optimism that a deal is near, and that Monday\'s EU summit will draw a line under the debt crisis and allow governments to move on to pro-growth measures. The finance ministers of Germany and France and the head of the European Central Bank were in Davos to debate strategy and defend the beleaguered single currency area after it was attacked by Britain\'s leader. They will all then meet again on Monday in Brussels for the latest in a series of high stakes EU summits, the bloc\'s first since Standard & Poor\'s downgraded the credit rating of a slew of eurozone member states. And US Treasury Secretary Timothy Geithner was to debate the outlook for world economy after the Obama administration acknowledged that the eurozone slump is undermining American growth ahead of the November election. The annual forum has been marked by gloom about the state of the global economy, and in particular about Europe\'s struggle to cope with yawning public deficits while at the same time seeking growth and jobs. The euro has been under pressure -- amid fears that Greece or even eventually a giant like Spain or Italy could default on its debts -- and the 17-nation bloc\'s economy in on the brink of renewed recession. A fortnight after France was stripped of its triple A credit rating, Finance Minister Francois Baroin will join his German counterpart Wolfgang Schaeuble in a debate entitled: \"How will the eurozone emerge from the euro crisis?\" After the Friday the 13th downgrade by Standard and Poor\'s, Baroin said the development was \"not a catastrophe\" and insisted that the government rather than the ratings agencies would decide French policy. But the Davos meeting has reverberated with calls for eurozone nations to act decisively to restore confidence, Canada\'s leader Stephen Harper said that Europe\'s capitals have been guilty of complacency. British Prime Minister David Cameron also piled on the pressure, reviving his simmering feud with the rest of Europe on Thursday by savaging France and Germany\'s plans for a new financial transactions tax. \"Even to be considering this at a time when we are struggling to get our economies growing is quite simply madness,\" he declared. The eurozone has caused alarm far beyond the continent and Mexican President Felipe Calderon used his speech Thursday to urge Europe to \"bring out the bazooka immediately\" to prevent the problem from sinking Italy and Spain. \"It is necessary to bring out the bazooka immediately, before the gunpowder gets wet,\" said Calderon, who holds the rotating chair of G20 world powers. \"Don\'t forget that we are in the same boat. It is not just a question of a possible implosion of the euro, but a crisis across the world.\" Geithner\'s address comes a day after the Federal Reserve cut its US growth forecast to 2.2-2.7 percent, about one-quarter percentage point below the previous forecasts, citing the eurozone crisis. \"We continue to see headwinds coming from Europe,\" Fed chairman Ben Bernanke said at a news conference. The third day of the Davos gathering also focused on events in the Middle East and North Africa, with an address from Hamadi Jebali, the post-revolution Islamist premier of Tunisia, and a debate on Iran\'s nuclear ambitions. Jebali\'s appearance is designed to imbue a rare spirit of optimism but he will speak just as eyes will be turned towards the head of the UN\'s atomic watchdog as he discusses the implications of Iran acquiring a nuclear bomb. International Atomic Energy Agency chief Yukiya Amano will be joined at the debate by Ehud Barak, the defence minister of Iran\'s arch foe Israel.