Firms which had World Trade Center offices

Allianz American Express Bank of America Cantor-Fitzgerald Citigroup Commerzbank Credit Suisse Group Dai-ichi Bank Deutsche Bank Fuji Bank ICAP Kemper Insurance Lehman Brothers Mizuho Holdings Morgan Stanley New York Board of Trade Nikko Securities Salomon Brothers Sinochem American Holdings of China Sumitomo Mitsui Banking Corporation Sun Microsystems TradeWeb Zim-American Israeli Shipping (A selection only)

Thousands of professionals in the World Trade Center are presumed dead, and rival banks have been co-operating to account for all their staff.

Some of the world's most powerful financial institutions will also be trying to patch up operations crippled by the carnage to lower Manhattan.

Most of Wall Street's major markets, including the New York Stock Exchange, bond markets and commodity exchanges, will be closed for a second day on Wednesday but foreign exchange markets will reportedly be open.

Morgan Stanley has posted phone numbers on its website for institutional investors to find out the position of their investments.

Other banks are making contingency plans to move to emergency trading floors outside New York.

But for most members of the US financial community, the personal loss of friends and colleagues in the World Trade Center and surrounding buildings has overshadowed concerns about when normal trading will resume.

Towering tenants

The attacks on the twin towers of the World Trade Center came as trading in New York was getting underway on Tuesday.

Many major Wall Street financial institutions were based in the five buildings that made up the World Trade Center.

Morgan Stanley was the largest tenant in one of the two towers, where about 3,500 of its retail brokers were stationed on 25 floors.

"Our immediate focus and concern are for the well-being and safety of Morgan Stanley employees," the company's website said on Tuesday.

In a broadcast the company's chief executive Philip Purcell said the "vast majority" of employees got out safely, but added that some were still missing.

"We think it is going to be much less bad than it appeared during the day yesterday," he said.

London-based Cantor-Fitzgerald, one of the world's largest inter-dealer brokers, and the recently spun off ESpeed, had operations on the 101st and 103rd to 105th floors, and employed 1,000 in the building.

ICAP, formerly Garban-Intercapital, the world's largest inter-dealer broker, said its entire New York offices located on three floors of the World Trade Center were destroyed and that a small number of staff are still unaccounted for.

Neighbouring tower collapses

Salomon Smith Barney leased a smaller office tower in the complex that collapsed late on Wednesday.

Deutsche Bank had 350 employees based in the World Trade Center.

San Francisco-based ABM Industries had more than 800 engineers, janitors and lighting technicians working in the building.

Lehman Brothers and American Express both had their corporate headquarters in adjoining buildings.

The New York Board of Trade, which is located at Four World Trade Center adjacent to the collapsed towers, has suspended trade and there has been no information about the condition of its trading floors.

Other firms in the immediate vicinity include Goldman Sachs, Merrill Lynch, JP Morgan and Oppenheimer Funds.

The New York Stock Exchange was undamaged and the American Stock Exchange computer systems and telephones were working on Tuesday.