NEW YORK, 11 August 2007 — Global stock markets fell and high-yielding currencies lost value yesterday, even as central banks pumped extra cash into the financial system to help temper fears of a liquidity crisis gripping investors.

Worldwide, central banks have injected at least $326 billion into their financial systems in the past 48 hours in an effort to prevent a global liquidity crunch that has its roots in the riskiest end of the US mortgage market.

In its biggest single day of temporary open market operations in nearly six years, the US Federal Reserve added $38 billion in reserves in three moves, the first coming before US stock markets began trading.

US stocks opened sharply lower, following the pattern of steep losses in European and Asian stock indexes.

The European Central Bank added 61.05 billion euros ($83.6 billion) yesterday, less than its record-setting sum of 94.841 billion euros on Thursday. Asian authorities also added cash to their financial systems on Thursday and yesterday.

What started as trouble with risky US residential mortgages is buffeting world financial markets as the fallout hits banks globally, squeezes once ample liquidity, and threatens to damage world economic growth.

The International Monetary Fund said the global market turmoil should be “manageable.” The multilateral lender said global economic growth should not be derailed by the mortgage and credit jitters.

“While the situation is still evolving, we continue to believe that the systemic consequences of the reassessment of credit risk that is taking place will be manageable,” said IMF spokesman Masood Ahmed. “The fundamentals supporting strong global growth remain in place, and the re-establishment of credit discipline that is occurring is a healthy development,” he said.

The Dow Jones industrial average was down 81.62 points, or 0.62 percent, at 13,189.06 — well off its session low at 13,057.86 by 1918 GMT. The Standard & Poor’s 500 index was down 5.63 points, or 0.39 percent, at 1,447.46, off its session low at 1,429.74. The NASDAQ composite index was down 20.62 points, or 0.81 percent, at 2,535.87. Earlier in the day, the NASDAQ hit a session low at 2,503.16.

“To some degree, you’ve got people saying things are still pretty good. We’re not going into a recession,” said Rick Campagna, portfolio manager at Provident Investment Council in Pasadena, California.

“But there is still an incredible amount of fear in the market, and rumors every hour it seems,” he said.

World stock markets have shed over nearly 8 percent since they hit record highs only a month ago. As a result, investors rushed to buy safe-haven government bonds, unwind yen-financed carry trades, and moved to scale back expectations for interest rate rises by some major central banks this year.

US benchmark 10-year Treasuries gave up early gains to trade flat, leaving the yield at 4.78 percent. The benchmark JP Morgan Emerging Markets Bond Index Plus showed yield spreads wider by 3 basis points to 206 basis points over US Treasuries.

Emergency action by central banks underlined the risk that a global liquidity crunch was more serious than anticipated. “What we have at the moment is just an all-round sense of panic,” said Marc Ostwald, bond analyst at Insinger de Beaufort in London. “Quite clearly there’s a lot of deep-seated fear out there and it’s going to take a while to resolve this.” Volatility across markets is hitting banks and corporations, as they have a harder time accessing the financing essential in making takeover deals.

London’s FTSE 100 dropped 3.7 percent to 6,038.30, the CAC-40 in Paris fell 3.1 percent to 5,448.63 and Germany’s DAX index was down 1.5 percent to 7,343.26.

In Asia, the Nikkei 225 index dropped 2.4 percent to close at 16,764.09 points on the Tokyo Stock Exchange. The broader Topix index of all shares on the exchange’s first section sank 3 percent.

Hong Kong’s blue chip Hang Seng Index shed 2.9 percent to finish at 21,792.70.