国际英语新闻：Dow down 3% after deepest intra-day plunge

But the market had been heading downward as fears of the spreading of Greece's sovereign debt crisis mounted. The plunge came shortly after the approval of a set of new austere measures in the Greek parliament sparked social riot in Athens.

The euro extended its decline against the U.S. dollar to a fresh 14-month low, putting commodities under great pressure. Crude oil prices tumbled to 77.11 U.S. dollars a barrel on Thursday, more than 10 percent down from loss compared with Monday 's close and the lowest level since February. Investors were also worried a spiking dollar could cut into earnings of U.S. companies as Europe was a major market for lots of them.

Traders work in New York Stock Exchange in New York, the United States, May 6, 2010. U.S. stocks tumbled more than three percent across the board on Thursday after fears of contagion from Greece debt crisis triggered uNPRecedented sell-off during trading.

Thursday's economic data provide little boost for the market. According to the Labor Department, initial claims for unemployment insurance fell by 7,000 to a seasonally adjusted 444,000. It was the third straight time for the number to drop, a sign the job market is slowly improving but the decline was smaller than economists had expected.

As of market closing, the Dow Jones industrial average dropped 347.80, or 3.20 percent, to 10,520.32. The Standard & Poor's 500 index tumbled 37.72, or 3.24 percent, to 1,128.15 and the Nasdaq lost 82.65, or 3.44 percent, to 2,319.64.