* U.S. stocks extend rally on Greece bailout speculation
* Euro rises against dollar, best day in 2-1/2 months
* Dow Jones industrials above 10,000
* Commodity prices gain on U.S. dollar woes (Updates with Greek developments, comment, U.S. markets)
By Daniel Bases
NEW YORK, Feb 9 (Reuters) - Investors plowed cash back into stocks and the euro on Tuesday on news that euro zone countries had decided in principle to come to the aid of debt-laden Greece, whose fiscal problems have soured risk appetite.
A spokesman for the German government, however, later denied as unfounded reports that various options were being considered to help Greece regain its fiscal footing and limit financial contagion, trimming the euro's gains against the dollar. [ID:nBAT005106]
The greenback's drop helped lift spot gold prices 1.5 percent and crude oil surged 3 percent.
The Dow Jones industrial average surged almost 2 percent and other major U.S. indexes rose more than 1 percent as the news about Greece revived an appetite for risk.
"I would see that as good news, knowing that there's a backer there, that those nations will be able to back up the (Greek) debt," said John O'Brien, senior vice president at MKM Partners LLC in Cleveland.
European Union leaders will hold a special summit on the economy on Thursday in Brussels amid the increasing worries that Greece and other so-called peripheral euro zone economies, including Spain and Portugal, cannot handle their debts and deficits.
EU Economic and Monetary Affairs Commissioner Joaquin Almunia said the situation in Greece was difficult and a common concern for the EU. [ID:nLDE6181VR]
In midday U.S. stock market trade, the Standard & Poor's 500 stock index <.SPX> was up 1.41 percent at 1,071.68 while the Dow Jones industrial average <.DJI> was up 1.71 percent at 10,078.21.
Brokerage comments also helped lift industrials such as
construction equipment maker Caterpillar. Caterpillar's stock
surged 5.51 percent to $53.58
Stocks in Europe, however, missed out on much of the Greek developments and closed flat after having gained early on thinner speculation about a bailout for the fiscally strapped euro zone member.
In Europe, the FTSEurofirst 300 <.FTEU3> rose 0.17 percent to 979.33, although year-to-date losses are around 6 percent.
"This is a little bit overblown," said Robert Quinn, European strategist at Standard & Poor's equity research, of the worries about Greece. "You know it's going to be bailed out eventually. Is it the EU? Is it the IMF? It doesn't matter. They are not going to default."
Spreads between German 10-year bonds
The euro climbed 1.05 percent at $1.3793
The U.S. dollar was down 0.61 percent against a basket six major currencies <.DXY>.
The euro is down 4.0 percent versus the dollar year-to-date and over 7.5 percent against the yen, in part because of concerns over debt.
Spot gold
Benchmark 10-year U.S. Treasuries fell 11/32 of a point in
price, pushing the yield up to 3.61 percent
STOCKS REBOUND
World stocks as measured by MSCI <.MIWD00000PUS> rose 1.1 percent, lifted mainly by gains of 1.96 percent in their emerging market component. Chinese and Hong Kong shares were generally higher, cheered by higher commodity prices.
Japan's Nikkei Nikkei <.N225> edged down 0.2 percent to a two-month closing low.
Toyota Motor Corp <7203.T>, whose shares have lost about a fifth of their value since late January, rose on short-covering with investors welcoming signs it was taking steps to deal with its safety problems.
The automaker announced a recall of the Prius and other hybrid cars for braking problems. (Additional reporting by Gertrude Chavez-Dreyfuss, Emily Flitter in New York; Jeremy Gaunt, Atul Prakash and Neal Armstrong in London; Marcin Grajewski in Strasbourg; Editing by Leslie Adler)