Bond trading resumed Thursday after a two-day shutdown as the financial markets began limited operations following the World Trade Center attacks.

Treasury bond trading began at 8 a.m. and the Chicago Board of Trade, where futures contracts are traded, opened in an abbreviated session.

Stock trading, however, remained halted for a third day as the New York Stock Exchange, Nasdaq Stock Market and other financial markets regrouped in hopes of reopening by no later than Monday after the assault that shuttered Wall Street on Tuesday.

It was not known when operations would resume at the New York Mercantile Exchange, where energy and precious metals are traded, located near the trade center in a complex known as the World Financial Center.

In overseas stock trading, Asian markets staged a modest recovery Thursday, while European markets opened almost unchanged. Market activity on both continents Europe was subdued as investors awaited the reopening of U.S. stock exchanges.

The attacks knocked out electricity, phone and other basic services across Manhattan's financial district, and market officials said it might take until Monday to restore them.

Hundreds of companies' offices were destroyed, and hundreds of other firms were forced to flee buildings that were damaged or shuttered by the destruction. Even as they sought word on missing employees, the firms worked nonstop to set up operations at replacement offices far from Wall Street's narrow alleys.

Many firms, while speaking of their new arrangements, would not specify exact locations for security reasons.

Information services company Electronic Data Systems Corp. was hustling to set up temporary New Jersey offices for a large brokerage whose World Trade Center quarters were destroyed. EDS would not identify the company.

Merrill Lynch cannot access its football field-sized trading floors in the World Financial Center, which also suffered significant damage.

"We have contingency plans for activities to be carried out at other locations. In fact, I'm speaking to you from an emergency location right now," said Merrill Lynch spokesman Rich Silverman.

Still, the industry's task was made somewhat easier because many financial firms have their operations in other parts of New York or in other cities.

Although Bear Stearns kept a facility in the financial district to help process trades, its primary operations are in midtown Manhattan and New Jersey, said spokeswoman Elizabeth Ventura.

"Our ability to trade was not impaired by this horrible tragedy," she said. "But we do have emergency backup facilities. We have very large trading facilities ready that we would be able to move into were there an emergency."

Morgan Stanley, the biggest tenant in the World Trade Center towers, keeps its trading desk elsewhere in New York. The towers were home to stock brokers who dealt with investor accounts, which are being relocated to other offices.

With its corporate headquarters in the World Financial Center inaccessible, American Express is shifting staff to other Manhattan locations and New Jersey. The company's trading operations are in Minneapolis, said Ted Truscott, chief investment officer at American Express Financial Advisors.

Larger financial companies keep duplicate computer networks and store data in sites outside Manhattan, making restoring operations possible, said Dan Burke, a brokerage industry analyst for Gomez Advisors of Lincoln, Mass.

"They can be up and running very quickly in an alternate location," Burke said.

Problems occur with smaller companies that back up information manually, rather than maintaining duplicate computer networks. For them, data on trades executed Monday night on overseas markets might not have been saved before the attacks, said John Jackson, president of the disaster recovery division for Comdisco, of Rosemont, Ill.

"Based on my knowledge of the companies, there is some significant data loss," said Jackson, whose company is helping rebuild networks for six World Trade Center-based companies and 29 others whose nearby offices are shuttered. "Anything they've done since the last backup occurred is lost."

Typically, the missing data is retrievable through paper records or employees' memory.

"But in this case, all the paper is gone because the building is gone. The employees who might otherwise been able to recreate the transactions might've been killed," said Jackson, whose company also recovered data for companies displaced in the 1993 World Trade Center bombing.