(Recasts with U.S. markets, adds byline; changes dateline; previous LONDON)
By Herbert Lash
NEW YORK, April 23 (Reuters) - U.S. stocks were mostly lower on Wednesday as new worries about bond insurer Ambac dragged down financial shares, offsetting optimism about technology sector earnings, while the euro posted its biggest drop against the dollar in three weeks.
Oil eased from a record high of nearly $120 a barrel on Tuesday after crude oil stocks in the United States rose more than expected last week.
The euro fell as soft economic data and comments by European policy-makers indicated a weak U.S. currency is hurting economic growth in the euro zone, curbing expectations that the European Central Bank will further increase interest rates.
Ambac Financial Group<ABK.N> on Wednesday posted a surprising wide first-quarter loss, and its shares plunged 41.6 percent to $3.52 amid worries about its outlook.
Financial shares <.GSPF> declined 1.2 percent as investors fretted anew about the impact of the subprime mortgage fallout.
"Ambac lost more money than people thought," said Al Goldman, chief market strategist at Wachovia Securities in St. Louis. "That was kind of a shock to the system, but I think that is a worry that will be on the back burner soon."
The Nasdaq, however, rose on strong results from chipmaker Broadcom <BRCM.O> and expectations that iPod maker Apple <AAPL.O> will deliver robust earnings when it reports after the bell on Wednesday.
The Dow Jones industrial average <
> was up 0.81 points, or 0.01 percent, at 12,721.04. The Standard & Poor's 500 Index <.SPX> was down 1.35 points, or 0.10 percent, at 1,374.59. The Nasdaq Composite Index < > was up 14.63 points, or 0.62 percent, at 2,391.57.An above-consensus earnings report from Boeing Co. <BA.N>, however, lifted investor optimism.
"Boeing's earnings were very impressive and that has helped the market," said Warren Simpson, managing director at Stephens Capital Management in Little Rock, Arkansas.
"But until the financials get out the mess that they've got themselves into the market's going to struggle," he said.
Results at Boeing, which has been beset by delays with its 787 Dreamliner, easily beat Wall Street forecasts on increased deliveries of commercial planes and more efficient manufacturing operations.
Broadcom, meanwhile, beat its quarterly revenue target and forecast sales growth in the current quarter, relieving investor concern about enterprise spending in a weak U.S. economy.
Broadcom shares surged more than 13 percent and Boeing's stock added 5 percent.
In Europe shares ended a volatile session in positive territory as optimism over earnings outside the financial sector helped offset concern about more banking write-downs.
The FTSEurofirst 300 index <
> of top European shares rose 0.7 percent at 1,313.20 points.Optimism in the technology sector and bid talk in industrials helped push up shares in chip equipment maker ASML <ASML.AS> by 7.7 percent and in France's Alstom <ALSO.PA> by 4.6 percent on talk that telecoms and construction group Bouygues <BOUY.PA> may increase its stake in the group.
"The earnings season has come in a bit better so far and we have had a representative sample" of companies reporting, said Philippe Gijsels, a strategist for Fortis Bank in Brussels.
"Outside financials, things are fairly good, especially in technology, where we've had some good figures," he said.
Demand for the euro fell after the decline in manufacturing and comments by European Central Bank Governing Council member Christian Noyer dampened speculation of further rate hikes.
The RBC/NTC Eurozone Purchasing Managers Index for manufacturing dropped to 50.8 in April, near a three-year low. German manufacturing activity also fell, although both German and euro zone readings for the service economy rose.
"The market may have gotten ahead of itself betting on a rate hike by the ECB," said Omer Esiner, a market strategist at Ruesch International in Washington.
The euro <EUR=> fell 0.50 percent to $1.5907, while the dollar rose major trading-partner currencies, with the U.S. Dollar Index <.DXY> up 0.63 percent to 71.792.
Against the yen, the dollar <JPY=> rose 0.39 percent to 103.39.
Euro zone government bonds rose as markets scaled back expectations for a possible boost to ECB interest rates.
The latest weekly fuel inventory data from the U.S. Energy Information Administration showed a bigger-than-expected rise in crude oil inventories and a big drop in gasoline stocks, which pushed oil prices lower.
"There's plenty of crude out there," said Phil Flynn, analyst at Alaron Trading.
U.S. light sweet crude oil <CLc1> fell 4 cents, or 0.03 percent, to $118.03 per barrel.
Gold shed more than 2 percent as the dollar gained ground and oil beat a retreat.
After midday, spot gold prices <XAU=> fell $12.10 to $905.20.
The 30-year U.S. Treasury bond <US30YT=RR> fell over a full point in price in curve-steepening trades and rising concerns about growing inflation.
The benchmark 10-year U.S. Treasury note <US10YT=RR> was down 12/32, with the yield at 3.745 percent. The 2-year U.S. Treasury note <US2YT=RR> was down 1/32, with the yield at 2.2143 percent. The 30-year U.S. Treasury bond <US30YT=RR> was down 30/32, with the yield at 4.5088 percent.
Asian shares shrugged off near-$120 a barrel oil and a weak dollar to resume an equities rally that has recovered all the ground lost last month.
MSCI's index of Asian stocks outside Japan <.MIAPJ0000PUS> rose 1.1 percent, and has gained 17.4 percent since March 18.
Japan's Nikkei average index <
> forged ahead early in the day but gave up most of its gains to close up 0.2 percent. (Reporting by Kristina Cooke, Vivianne Rodrigues in New York and Jane Merriman, Atul Prakash in London; Editing by Leslie Adler)