* U.S., European stocks slide; financial shares lead fall
* Bonds rise; financial sector fears boost safe-haven bid
* Report of trimmed IMF growth forecasts weigh on markets
* Oil rebounds after signs its rally fizzled; Iran says OPEC on guard (Recasts with U.S. markets, adds byline; changes dateline; previous LONDON)
By Herbert Lash
NEW YORK, Aug 25 (Reuters) - U.S. and European stocks fell on Monday as persistent credit and global growth concerns slammed equities and led investors to seek the safety of government debt on both sides of the Atlantic.
The decline U.S. assets reduced demand for the dollars to buy them and pushed investors into investments perceived as less risky, such as the yen and government debt.
Crude prices edged higher in thin, seesaw trade. Oil investors made wary by a volatile dollar and an upcoming meeting of the Organization of Petroleum Exporting Countries Sept. 9 that will focus on a recent slide in prices.
Investors flocking to government debt pushed benchmark yields on U.S. Treasuries to 3-month lows while bund futures in Europe posted their biggest one-day rise in a month. Bonds prices and yields move inversely to each other.
The dollar's intra-day gains on a better-than-expected U.S. existing-home sales report were short lived, even though a recovering or stabilizing U.S. housing market is seen as critical to restoring investor confidence in the U.S. economy.
The British pound hit two-year lows against the dollar, with stalled UK growth seen as another example of growing economic malaise outside the United States.
Analysts said price moves were exacerbated by thin volume due to a bank holiday in the United Kingdom and the last week of summer for financial markets.
"Ongoing credit angst is giving us some flight-to-quality trade, but trade is pretty thin," said Kim Rupert, managing director of global fixed income analysis at Action Economics LLC in San Francisco.
U.S. stocks slid almost 2 percent, erasing Friday's sharp gains, as financial shares slid.
American International Group Inc <AIG.N> fell to a 13-year low after
Credit Suisse cut its price target and forecast a huge third-quarter loss for American International Group Inc <AIG.N>, citing bigger losses from its derivatives business. AIG shares fell 5.4 percent to a 13-year low.
Concern grew as Lehman Brothers <LEH.N> shares fell more than 7 percent after a top South Korean regulator expressed reservations about state-run Korea Development Bank's interest in buying a global bank.
Further fueling concerns of possibly further fallout from the credit crisis, bank regulators shut Columbian Bank and Trust Co late Friday, the ninth U.S. bank to fail this year.
"Financial stocks are pretty much in the red across the board," said Al Kugel, chief investment strategist for Atlantic Trust in Chicago.
"They're the main determinant of the direction of the overall market, and it's hard to make progress when they are down," he said.
Among industrial conglomerates with big overseas exposure, Caterpillar <CAT.N> shed 2.5 percent. The International Monetary Fund trimmed its forecasts for 2008 and 2009 world economic growth in a note prepared for the meeting of the Group of 20 nations, a G20 finance official told Reuters.
Before 1 p.m., the Dow Jones industrial average <
> was down 240.43 points, or 2.07 percent, at 11,387.63. The Standard & Poor's 500 Index <.SPX> was down 25.66 points, or 1.99 percent, at 1,266.54. The Nasdaq Composite Index < > was down 52.02 points, or 2.15 percent, at 2,362.69.European shares also fell on persistent financial sector worries, with Spanish bank Santander <SAN.MC> and Dutch-Belgian financial group Fortis <FOR.AS> both dropping 2.4 percent.
The FTSEurofirst 300 <
> index of top European shares ended 0.56 percent lower at 1,169.17 points.Lower crude oil prices <CLc1><LCOc1> extended the previous session's steep slide in energy majors. Royal Dutch Shell <RDSa.AS> fell 1.8 percent and Total <TOTF.PA> 1.4 percent.
The IMF's lowered economic growth projections signaled weaker demand and hit shares in steel maker ArcelorMittal <MTP.PA>, down 2.2 percent, and engineering conglomerate Siemens <SIEGn.DE>, off 1.6 percent, among European big caps.
Tension between the West and Russia over Georgia and expectations that OPEC would trim production should crude prices fall further helped pushed oil slightly higher.
The U.S. dollar pared some losses against the yen after data showed U.S. existing home sales rose more-than-expected in July.
The dollar fell against major currencies, with the U.S. Dollar Index <.DXY> down 0.12 percent at 76.684. Against the yen, the dollar <JPY=> fell 0.75 percent at 109.18.
The euro <EUR=> fell 0.06 percent at $1.4782.
The pound later recovered but its weakness helped the revival of the dollar against some currencies including the euro.
The benchmark 10-year U.S. Treasury note <US10YT=RR> rose 24/32 to yield 3.78 percent. The 30-year U.S. Treasury bond<US30YT=RR> rose 39/32 to yield 4.39 percent.
The dollar's rally sparked a rebound in Asian stocks from a two-year low as the drop in oil prices back below $120 a barrel lifted shares of companies sensitive to energy prices.
U.S. light sweet crude oil <CLc1> rose 29 cents to $114.88 a barrel.
Spot gold prices <XAU=> fell 5 cents to $822.05 an ounce. Japan's Nikkei share average <
> ended up 1.7 percent, and MSCI's Asia-Pacific ex-Japan index <.MIAJP00000PUS> rose 1.2 percent. (Reporting by Kristina Cooke, Chris Reese, Nick Olivari and Frank Tang in New York and Ian Chua, Alex Lawler in London and Peter Starck in Frankfurt) (Reporting by Herbert Lash. Editing by Richard Satran)