TOKYO — A massive sell-off on Wall Street and an escalating global equity crisis sent Asian stocks plunging today, with Japan's benchmark Nikkei 225 index tumbling nearly 10 percent.

"Selling is unstoppable in New York and Tokyo," said Yutaka Miura, senior strategist at Shinko Securities Co. in Tokyo. "Investors were gripped by fear."

In early afternoon trading the Nikkei was down more than 900 points. By the close it had had recovered slightly, finishing down 881.06 points, or 9.6 percent, at 8,276.43.

Other indexes in the region also fell sharply during the trading session. Hong Kong's Hang Seng index tumbled by as much as 8 percent, South Korea's Kospi was down 7.4 percent at one point, and Singapore's Straits Times index was off by as much as 7.0 percent during the day. In Sydney, Australia's S&P/ ASX200 closed down 8.3 percent.

Today's Asian market declines follow a 7.3 percent plunge in the Dow Jones industrial average yesterday; the Dow closed below 9,000 for the first time in five years. Stocks nosedived after a major credit-rating agency said it might cut its rating on General Motors Corp. and Ford Motor Co., further rattling investors already fretting over the impact of tight credit on the economy.

The Dow's 2,271-point tumble over the last seven sessions is its steepest seven-day point drop ever. Its seven-day percentage decline of 20.9 percent is the largest since the seven-day plunge ending Oct. 26, 1987, when the Dow lost 23.8 percent. That sell-off included Black Monday, the Oct. 19, 1987, market crash that saw the Dow fall nearly 23 percent in a single day.

Lucinda Chan, associate director of Macquarie Equities in Sydney, called the market moves "ghastly."

"It is a very different and very unprecedented climate at the moment," she said. "Growth is going to be a major concern in this market and that is why the Australian market is getting a very hard pinch, because we are a commodity export nation."

Miura in Tokyo said the ongoing meltdown in global financial markets shows "confusion and uncertainty" among investors worldwide.

Asia's falls come as finance ministers and central bankers from the Group of Seven industrialized nations are to meet today in Washington.

"Investors are not so sure that the G7 will announce effective measures to contain the global financial crisis," Miura said.

Shares of Mitsubishi UFJ, Japan's biggest bank, lost 8.5 percent. The company is in talks to buy a stake in Morgan Stanley.

"It's a financial panic," said Choi Min Jai, who oversees the equivalent of $2.1 billion at KTB Asset Management Co. in Seoul. "The recession can only get worse. You can't find the link that will break the vicious cycle."

The yen has risen 6.4 percent this week against the dollar and today touched 97.92, the strongest since March 19. Japan's currency was at 134.49 versus the euro, from 145.11 on Oct. 3, heading for the largest weekly gain since the single currency's creation in 1999.

"The basic trend is to buy the yen," said Hideki Amikura, deputy general manager of foreign exchange at Nomura Trust and Banking Co. Ltd., a unit of Japan's largest brokerage. "The credit crunch is spreading from the financial sector to other companies, meaning currency traders can't take on risk. The G-7 may not be able to repair money markets quickly enough."