But as Japan awaited news of whether dozens of bankers and businesspeople were alive, economists began expressing fears Wednesday of another possible casualty - the world's already shaky economy.

In Hanoi, Vietnam, where trade ministers from around Southeast Asia were meeting for an annual summit, concerns were expressed that fallout from the attacks could be devastating.

''We hope that it doesn't dampen people's confidence in one another because that's the basis for the global economy,'' said Rodolfo Severino, secretary-general of the Association of Southeast Asian Nations.

For Japan, the world's second-largest economy, the prime concern in the aftermath of the attacks was to avert a confidence meltdown.

A crisis management office was set up at the Bank of Japan, which promised to provide ample cash in the money market and to be ready to deal with any disruptions in the financial sector.

Though postponed by 30 minutes, the Tokyo Stock Exchange opened for business Wednesday morning - a move Hakuo Yanagisawa, the minister in charge of financial services, said he took to maintain the market's international credibility.

But it was a gamble - Tokyo share prices, already battered by a recent economic slowdown, plunged below the 10,000-yen level, hitting a 17-year low soon after trading began.

''We ask for a calm response from market players,'' Yanagisawa said.

Response elsewhere in the region was mixed.

In Thailand, stock markets were closed indefinitely. Singapore's financial markets stayed open, and the Monetary Authority of Singapore, the city-state's de facto central bank, promised to ensure ample money flow in the banking system.

Song Seng Wun, a regional economist for GK Goh Research in Singapore, warned the attacks could push Asian economies onto thinner ice and said rushing back to business was not necessarily the wise thing to do.

''We're still trying make sense of a very chaotic situation,'' he said, adding the Singapore stock market probably should have stayed closed until ''some semblance of order'' returned.

Thai Finance Minister Somkid Jatusripitak said he was worried about oil prices, which jumped by more than $3 to about $30 a barrel. Thailand has stopped all exports of petroleum products to ensure the country's reserves.

''The whole world is in a turmoil,'' Somkid said.

A problem looming for Japan's corporate giants is the weakening dollar. The greenback dropped significantly against the yen in trading Wednesday as worries grew about what effect the attacks will have on the American economy.

Japan depends heavily on exports, particularly to the United States. A strong yen is devastating for exporters because it drives down profits from overseas and makes Japanese products more expensive abroad.

To keep that from happening, Finance Minister Masajuro Shiokawa indicated that Japan is ready to step in to stabilize currency trading.

''If the foreign exchange rate continues to swing as a result of this terrorist attack, we're ready to intervene in the market,'' he said.

Shiokawa said he had discussed this with U.S. Treasury Secretary Paul O'Neill, who was in Tokyo on the last stop of his Asian tour. The two spoke by telephone, as O'Neill had canceled his schedule here and was expected to fly back to Washington soon.

For the Japanese companies with employees in the towers, just assessing the damage was an almost impossible task.

Yasushi Miyama, a spokesman for Fuji Bank, whose 12 New York-assigned employees were still missing, acknowledged that telephone lines to New York weren't connecting. He said no damage to the regular banking operations had been reported.

''I don't know where you draw the line as damage on business,'' he said. ''Our operations aren't going perfectly, but the damage has not been huge.''

Other companies with crucial business in the United States remained unsure of what they faced ahead.

Japanese automaker Honda Motor Co. said its assembly lines in Ohio are still open but may be affected if parts shipments from Japan and Canada don't arrive on time.

''We are watching the situation day by day,'' said Honda spokeswoman Noriko Okamoto.

Tokyo-based shipping company Nippon Express Co. was checking on the whereabouts of its cargo after all planes to the United States were sent back.

''Everything is still uncertain,'' said spokesman Koji Watanabe.