By Caroline Valetkevitch
NEW YORK (Reuters) - Copper and other metals plunged on Tuesday as the euro sank to a five-week low against the dollar after the European Central Bank tightened lending conditions for Greek banks and as the collapse in equities prices in China drove fears about the country's economy.
U.S. stocks ended higher, taking heart from a stabilization in oil prices, while a global stock index fell as European shares extended losses on worries about Greece's ability to secure fresh aid.
Investor worries about Greece's debt crisis and the country's possible exit from the euro zone also pushed benchmark U.S. 10-year yields to five-week lows.
"People woke up to the fact this morning about the risks to the global market, and Treasuries are the place to be for safety and liquidity," said Stanley Sun, an interest rate strategist at Nomura Securities International in New York.
Greek banks may soon run out of cash. Greek Prime Minister Alexis Tsipras launched another bid to win fresh aid at an emergency euro zone summit, but German Chancellor Angela Merkel said there was still no basis for reopening negotiations.
Failure to reach a deal would make it more likely Greece will drop out of the euro.
The Dow Jones industrial average rose 93.33 points, or 0.53 percent, to end at 17,776.91. The S&P 500 gained 12.58 points, or 0.61 percent, to 2,081.34 after briefly falling below its 200-day moving average. The Nasdaq Composite added 5.52 points, or 0.11 percent, to 4,997.46.
Nine of the 10 major S&P 500 sectors finished higher, with the utilities index up 2.48 percent.
MSCI's all-country equities world index lost 0.4 percent, while European shares ended down 1.6 percent.
The euro dropped to a five-week low against the dollar after the ECB left emergency liquidity aid for Greek banks at current levels, but increased the haircuts on the collateral it demands.
Against the dollar, the euro fell 0.7 percent to $1.0978, after sliding to a five-week low of $1.0917, while the dollar index rose 0.6 percent to 96.846, after earlier hitting a one-month high.
In the U.S. Treasury market, the 10-year note was last up 17/32 in price to yield 2.2153 percent after earlier yielding as little as 2.185 percent, a level last seen on June 2.
German 10-year bond yields fell to their lowest level since early June.
Gold fell to a near four-month low, while silver sank nearly 7 percent and platinum dropped to a 2009 low, as the dollar rallied.
A stronger U.S. currency makes dollar-denominated commodities more expensive for holders of other currencies.
Spot gold dropped to its lowest level since March 18 at $1,148.05 an ounce and was down 1.1 percent at $1,156.75. U.S. gold futures for August delivery settled down 1.8 percent at $1,152.60 an ounce.
Copper prices hit their lowest level in six years, falling to $5,318 a tonne, on the dollar gains and on concerns over demand from China, the world's biggest consumer, where stocks fell sharply overnight despite a slew of support measures unleashed by Beijing in recent days.
In the oil market, U.S. crude settled down 20 cents at $51.98 per barrel. Brent settled up 31 cents at $56.85.
Commodity currencies fell sharply, with the Australian dollar hitting a six-year low.
The Australian dollar, which is a proxy for Chinese investments, fell 0.7 percent to US$0.7440.
(Additional reporting by Michael Connor in New York, Nigel Stephenson in London, Hideyuki Sano in Tokyo; Editing by Meredith Mazzilli and Leslie Adler)