* Fate of U.S. auto makers darkens, hitting sentiment
* Japan officials stirred after US dollar drops below 90 yen
* 10-yr US Treasury drops to five-decade low below 2.5 pct
* Toyota stock down 10 pct, Honda down 13 pct
* Commodity prices tumble on demand fears (Repeats to additional subscribers with no change to text) (Recasts, adds details, quotes, European, U.S. outlook)
By Kevin Plumberg
HONG KONG, Dec 12 (Reuters) - Asian stocks plunged more than 5 percent on Friday after a collapse in the U.S. carmaker bailout jeopardised the industry, sending investors fleeing to the safety of government bonds and the yen, which shot to a 13-year high.
The suddenness of the move in the yen, which pushed the U.S. dollar below the sensitive level of 90 yen, fed concern Japanese officials would enter the market to stabilise their currency.
Investors bailed on stocks and piled into U.S. Treasuries, knocking the benchmark 10-year yield to the lowest in more than five decades, as the bargain-hunting that had helped to drive up shares in the last week dried up in the face of a worsening global economic backdrop.
U.S. stock futures gapped lower, with S&P 500 futures down 5 percent <SPc2>, pointing to a much lower open on Wall Street. while European stocks were also set to open sharply weaker. [
]The collapsed bailout led to weakness across commodities, everything from copper to crude and rubber, as investors speculated on even weaker demand for raw materials.
Without the help of the $14 billion package of loans, the potential for the so-called Big Three car manufacturers -- Ford Motor Co <F.N>, General Motors Corp <GM.N> and Chrysler LLC [
] -- to go under could kill investor sentiment, lead to higher unemployment and deepen the U.S. recession, economists said."What the failure of this deal does is that it will set back sentiment not only in the U.S., but also set back sentiment globally. There is going to be further risk aversion going forward," said Joseph Tan, chief Asian economist with Credit Suisse in Singapore.
The MSCI index of Asia-Pacific stocks outside Japan <.MIAPJ0000PUS> fell 5.4 percent, eroding more of its double-digit percentage gains in the last week. The index is down 56 percent on the year, easily the steepest decline since the gauge started in 1988.
Japan's Nikkei share average <
> sank 5.5 percent, snapping four days of rises.Shares of Toyota Motor Co <7203.T> were off 10 percent and Honda Motor Co <7267.T> off 12.7 percent on worries about massive disruption caused to the industry by the collapse of one of the U.S. automakers.
Hong Kong's Hang Seng index <
> was down about 7 percent, weighed by shares of PetroChina <0857.HK><601857.SS>, Asia's top oil and gas producer, which tumbled 10 percent as crude prices dropped.RISK, ONCE AGAIN, IS SOLD
Even before the automaker deal fell apart in the U.S. Senate, Asian shares had already been under pressure because of unease about the shrinking financial sector and economic malaise.
"It shouldn't come as a surprise that Asian equity markets are selling off today on news of the U.S. auto bailout failure," said Tim Rocks, equity strategist with Macquarie Securities in Hong Kong.
"For Asia, the major issue is how much damage is being done to earnings and balance sheets, and we won't know until February when companies announce fourth-quarter earnings," he said.
The rapid shift out of risky assets on Friday propelled the yen. The U.S. dollar fell as low as 88.40 yen <JPY=>, the lowest since 1995, before recovering to around 89.75 yen.
The yen's spike prompted Japan's top financial diplomat, Naoyuki Shinohara, to say the currency movements were too volatile and the moves in the foreign exchange market were being watched with concern. The last time the Bank of Japan intervened in the market, on behalf of the Ministry of Finance, to cap the yen was in 2004.
"Without an intervention, the dollar could hit 85 yen, so Japan will likely intervene to prevent that from happening," said Masafumi Yamamoto, head of foreign exchange strategy with Royal Bank of Scotland in Tokyo.
"The worst case scenario for Japanese authorities is that the yen's appreciation pushes down Japanese share prices which will further aggravate of the economy, and they see it happening now."
In the bond market, the yield on the benchmark 10-year note <US10YT=RR>, which moves in the opposite direction of the price, slipped to 2.48 percent, the lowest in more than 50 years hit earlier this month.
Maturities of less than a year traded at barely any yield at all, with the 3-month bill yield <US3MT=RR> flitting between 1.5 basis points and zero. Year-end is usually a time when global investors and corporates pile into the highly liquid short-term U.S. debt market to keep cash safe and dress up balance sheets.
However, the ferocity of the global economic slowdown this year has made 2009's prospects particularly grim.
U.S. light crude for January 2009 delivery tumbled $2.25 to $45.73 a barrel, creeping back down toward a four-year low of $40.50 hit earlier in the month.
Remarks from OPEC President Chakib Khelil overnight about the need for a big cut in production increased speculation among traders that supply will be cut by 1-2 million barrels per day. (Editing by Lincoln Feast)