* Debt prices slump as U.S., Germany eye large tax cuts
* U.S. stocks fall on profit-taking; stocks rise in Europe
* Dollar at 3-week high vs euro on hopes for stimulus plan
* Oil jumps as Gaza fighting raises Mideast supply worries (Adds close of U.S. markets)
By Herbert Lash
NEW YORK, Jan 5 (Reuters) - U.S. Treasury prices plummeted on Monday, driven by fears a price bubble is about to pop in the face of a massive wave of new debt, while fresh details of a planned U.S. stimulus package helped firm up the dollar.
U.S. stocks fell after an early rally on better-than-expected December sales at battered General Motors failed to hold as investors booked profits from last week's run-up.
Oil prices rose more than 5 percent as Israel's deepening incursion into Gaza and a dispute between Russia and Ukraine over natural gas heightened worries of supply disruptions.
Prospects for a swelling supply of government debt drove U.S. and euro-zone prices down. The U.S. Treasury said it would sell $16 billion of reopened 10-year notes and $30 billion in three-year notes this week.
While the issuance was broadly in line with market forecasts, it underscored a looming surge of debt to fund government efforts to rescue the financial system.
U.S. President-elect Barack Obama plans $310 billion in tax cuts as part of a rescue package of up to $775 billion, senior Democratic aides said on Sunday.
German Chancellor Angela Merkel met her Social Democrat (SPD) coalition partners to discuss a second fiscal stimulus deal worth up to 50 billion euros ($68 billion).
The 30-year Treasury bond <US30YT=RR> fell more than four full points in price, pushing its yield above 3 percent, a dramatic rise from a record low near 2.52 percent on Dec. 18.
But the dollar rose, with not all investors taking such a dim view as the bond market's. The euro slipped to three-week lows versus the dollar, with weaker-than-expected Italian and Spanish inflation data and tax cuts in Germany expected to pressure the European Central Bank to cut rates further soon.
"The combination of tax cuts, infrastructure spending and job creation under the Obama stimulus package takes out some of the pain from the economic recession we're in," said Ron Simpson, director of currency research at Action Economics in Tampa, Florida.
"At some juncture the U.S. efforts would turn the economy around quicker than many of the other countries and that should be dollar-positive," he added.
After toying with positive territory through much of the session and briefly rallying on GM's sales, U.S. stocks ended lower, though GM's shares rose 1.6 percent.
The Dow Jones industrial average <
> closed down 81.80 points, or 0.91 percent, at 8,952.89. The Standard & Poor's 500 Index <.SPX> fell 4.34 points, or 0.47 percent, at 927.46. The Nasdaq Composite Index < > slipped 4.18 points, or 0.26 percent, at 1,628.03.Dow components Verizon Communications Inc <VZ.N> and AT&T <T.N> slid on a research downgrade, and financial stocks fell after Deutsche Bank cut its earnings forecast on 16 large banks, including JPMorgan Chase & Co <JPM.N>.
Verizon fell 6.2 percent, AT&T slid 3.4 percent and JPMorgan shed 6.6 percent.
Shares of Apple Inc <AAPL.O> rose after Chief Executive Steve Jobs dispelled investor concerns about his recent weight loss, saying it was a treatable hormone-related problem. Apple shares rose 4.2 percent.
European equities advanced for the fifth straight session, spurred by gains in shares of oil companies on rising crude prices and by the anticipation of further fiscal stimulus, drawing flows away from safer-haven government debt.
The FTSEurofirst 300 <
> index of top European shares ended 1.9 percent higher at 873.01 points.The telecommunications sector was one of the biggest gainers on the index on the first full day of 2009 trading for many, with Swisscom <SCMN.VX> rising 5.2 percent, Cable and Wireless <CW.L> adding 4.6 percent, Vodafone <VOD.L> up 4.3 percent and Portugal Telecom <PTC.LS> rising 4.6 percent.
Sharp losses for the euro, which was off 2.14 percent at $1.3579, also spread to euro/sterling, taking it to 0.9278, well away from record lows for the pound last week and easing momentum toward parity.
The dollar rose against a basket of major trading-partner currencies, with the U.S. Dollar Index <.DXY> up 1.59 percent at 82.80. Against the yen, the dollar <JPY=> rose 1.23 percent to 93.35.
Longer-maturity government debt fell, but shorter-term debt was little changed to higher. The benchmark 10-year U.S. Treasury note <US10YT=RR> fell 35/32 in price to yield 2.48 percent, and the 30-year U.S. Treasury bond <US30YT=RR> fell 156/32 in price to yield 3.01 percent.
Oil, up more than 35 percent since Israel launched its attack on Gaza on Dec. 27, rose on increasing concerns about the supply of crude from the Middle East.
U.S. crude <CLc1> gained $2.47 to settle at $48.81 a barrel after touching a three-week high of $49.28. London Brent <LCOc1> rose $2.40 to $49.31 a barrel.
"Saber rattling by Iran and further instability in the Middle East always produces fears for oil supplies, which is putting a platform under prices," said Bank of Ireland analyst Paul Harris.
Gold tumbled, briefly breaking below $850 an ounce as investors took profits on the dollar rally and signs of slowing physical demand in India, the world's top bullion consumer.
U.S. gold for February delivery <GCG9> settled down $21.70 to $857.80 an ounce in New York.
Asian stocks rose to a two-month high on hopes massive government spending programs will revive a global economic recovery later this year.
The MSCI index of Asia-Pacific stocks outside Japan <.MIAPJ0000PUS> climbed 2.7 percent, while Japan's Nikkei average <
> gained 2.1 percent in a shortened session to reach a two-month high. (Reporting by Richard Valdmanis, Gertrude Chavez-Dreyfuss, Chuck Mikolajczak, John Parry and Frank Tang in New York and Kirsten Donovan and Kylie MacLellan in London; writing by Herbert Lash; editing by Dan Grebler)