* Markets unconvinced by Greece debt bailout
* Euro drops to 14-month low, losing over 1 percent vs USD
* Government bonds surge, German bund yields at record low (Updates with comment, prices, Europe close)
By Daniel Bases
NEW YORK, May 5 (Reuters) - Fears of contagion from the Greek debt crisis knocked the euro to a 14-month low and sent world stocks reeling as violent protests erupted over Athens' austerity measures turned deadly and Moody's warned Portugal's debt could be downgraded.
Markets retraced ground from the day's lows but were still weaker in midday U.S. trade.
German bond yields surged on investor fears that a massive aid package would not be sufficient to ensure other fiscally weak euro-zone nations don't spiral down. U.S. Treasury prices drifted down from their highs but were still up on the day.
The euro lost 0.72 percent to $1.2887 <EUR=>, its lowest point since mid-March 2009. It is down roughly 3.5 percent against the greenback this week.
Skepticism that Greece can deliver on its promises of tough austerity measures dominated the markets.
"European contagion is really the name of the game. That's all we're watching," said Rick Klingman, managing director of Treasury trading at BNP Paribas in New York.
German bund yields hit a record low, while the cost of protecting Portuguese government debt against default hit a record high after credit rating agency Moody's Investors Service said Portugal was on review for a possible downgrade.
U.S. stocks were weaker on the contagion fear, taking little notice of a private sector report showing gains in the U.S. labor market for the first time since January 2008. [
]In midday New York trade, the Dow Jones industrial average <
> fell 30.31 points, or 0.28 percent, at 10,896.46. The Standard & Poor's 500 Index <.SPX> lost 3.53 points, or 0.30 percent, at 1,170.07. The Nasdaq Composite Index < > dropped 16.66 points, or 0.69 percent, at 2,407.59.The FTSEurofirst 300 <
> index of leading European shares pared losses slightly on strong results from market bellwethers like Societe Generale <SOGN.PA>. The index however closed down 0.95 percent, near a nine-week low.In Athens, striking public sector workers challenged Greece's bailout-for-austerity deal. Three people were killed when protesters set a central Athens bank ablaze. [
]Policymakers, including International Monetary Fund chief Dominique Strauss-Kahn and the European Central Bank's Axel Weber, warned of the dangers of contagion to other high-debt euro zone nations. [
]Portuguese credit default swap (CDS) prices surged to 407 basis points from 344 basis points, according to CDS monitor CMA DataVision. The firm said the levels implied a default rate of 29.6 percent.
Greece's CDS levels reached a record high of 850 basis points from 764.5 basis points at the New York close on Tuesday.
The two-year Schatz yield <EU2YT=RR> was spurred to a fresh record low of 0.569 percent. The Schatz, a short-dated euro zone government bond benchmark, was introduced in the early 1970s.
"What we're seeing is a complete sea change in the market assessment of risk," said Societe Generale economist James Nixon.
"Any country running what is obviously an unsustainable fiscal trajectory, and people ultimately don't want to be holding their debt...if you think there's a chance you won't get your money back."
The 10-year Portuguese/German government bond yield spread <PT10YT=TWEB><DE10YT=TWEB> widened to 310 basis points, a euro lifetime gap.
The equivalent Spanish spread <ES10YT=TWEB> widened to 136 bps, also a euro lifetime gap.
Investors bought the government bonds on the Greece fear factor, ignoring a report that said euro zone's economic growth should be stronger in 2010 than previously thought. [
]The price on benchmark 10-year Treasury notes <US10YT=RR> was up 8/32 for a yield of 3.56 percent, down from 3.60 percent late Tuesday.
World stocks as measured by MSCI <.MIWD00000PUS> fell 0.93 percent to their lowest since early March, while the more volatile emerging equities index <.MSCIEF> lost 1.81 percent.
Asian markets also weakened. Shanghai's key index <
> slid as much as 2 percent to its lowest in seven months, suffering from Beijing's weekend moves to tighten policy.Japan's markets have been closed this week, and are scheduled to reopen on Thursday.
Oil extended losses, losing $1.73, or 2.09 percent, to $81.01 per barrel, a day after its steepest one-day percentage loss in three months, on rising inventories and a firm dollar.
Safe-haven buying sent spot gold prices higher <XAU=>. The precious metal gained $1.50 to $1,172.60 an ounce despite strength in the greenback.
(Additional reporting by Emily Flitter in New York, Carolyn Cohn, Neal Armstrong, George Matlock, Kirsten Donovan in London) (Editing by Theodore d'Afflisio)