* U.S. dollar slides on uncertainty about Russia
* Yen climbs broadly after spike in volatility
* Oil briefly dips near $70, questions on demand remain
* Investors pause and see if prices reflect economic reality
By Kevin Plumberg
HONG KONG, June 16 (Reuters) - The U.S. dollar slid on Tuesday after Russia, before a meeting of the biggest emerging market powers, said the world needs new reserve currencies, while Asian stocks fell, as investors cut their holdings of riskier assets and bought yen.
A day after Russian finance minister Alexei Kudrin said the dollar's status as the world's main reserve currency would unlikely change in the near term, the country's president called for new ones, confusing investors about Russia's position.
With volatility creeping higher and uncertainty rife, investors as they did during the worst days of the financial crisis, turned to the yen.
Major European stocks opened slightly firmer, with the pan-European FTSEurofirst 300 gaining 0.27 percent.
according to financial bookmakers, with dealers watching resource-related shares closely after oil briefly fell below $70 a barrel, down for a third day after hitting the highest since October last week.
Japan's Nikkei share average closed 2.9 percent lower, the biggest single-day drop since March 30, led by a 4 percent decline in shares of Honda Motor Co.
The MSCI index of Asia Pacific stocks outside Japan fell 1.8 percent, with losses in the energy and materials sectors the biggest drag.
Materials stocks have been driven by a rapid rise in metals and other raw materials prices on hopes outperforming, large economies such as China's would keep devouring commodities.
Since the latest global equity rebound began on March 9, the MSCI all-country world index has risen 35 percent, but the materials sector has gained about 49 percent.
Hong Kong's Hang Seng index slid 2.8 percent. Resource-sensitive stocks were among the biggest drags on the market, with Asia's largest oil-and-gas producer PetroChina falling 4.2 percent.
"I don't see a lot of evidence of a really solid economic recovery. All I see is a moderation in the rate of decay," Frank Villante, chief investment officer at Souls Funds Management in Sydney.
The U.S. 500 stocks index fell 2.4 percent on Monday, the biggest daily decline since May 13. The Dow Jones industrial average and Nasdaq both dropped more than 2 percent.
IS VOLATILITY BACK?
The Chicago Board Options Exchange Volatility index, better known as the VIX, jumped 9.5 percent on Monday, the largest single-day rise since April 20.
The index, which is based on prices of options on the S&P 500, is used by global investors as a benchmark for risk taking.
The stronger indications of volatility ahead drove investors to buy the yen, which was one of the biggest movers in Asian trade. During the most violent days of the financial crisis, the yen consistently strengthened, thanks to Japan's relatively unscathed banking industry.
The U.S. dollar dropped 1.6 percent to 96.30 yen, while the euro fell 1.1 percent to 133.45 yen.
The euro rose 0.5 percent against the dollar to $1.3852 after earlier falling and testing a technical obstacle down around $1.3750.
The outlook for the euro darkened after an European Central Bank report said euro zone banks may need to write down another $283 billion, but equally potent were fears about how expensive it would be for the U.S. government to finance its growing budget deficit.
"The themes of dollar-debasement and a sick European banking sector are powerful ones and depending on which theme grows in intensity, the dollar could move decisively in either direction. Right now, the mood is for downside in euro/dollar," Ashley Davies, currency strategist with UBS in Singapore, said in a note.
U.S. crude futures were under pressure for a third day. The July contract was down 0.2 percent at $70.50 a barrel after earlier touching a session low of $69.90.
Investors continued to find some value in late maturity U.S. Treasuries. The benchmark 10-year yield slipped to 3.70 percent from 3.73 percent late in New York on Monday.
The 10-year yield is on its way to a fourth consecutive decline after reaching 4.01 percent last Thursday, its highest since mid October.
Many debt securities, including mortgage loans, are benchmarked against Treasury yields, so the quick rise in yields over the last month have investors spooked about the viability of the fragile recovery. (Additional reporting by Denny Thomas in SYDNEY; Editing by Kazunori Takada)