Updated

Tuesday's terror attack on New York's financial district destroyed a wealth of important data and documents, but many companies expect to be up and running soon thanks to back-up files in other locations.

Top financial companies such as Morgan Stanley, Deutsche Bank AG and Cantor Fitzgerald are among those now scrambling to reassure investors and retrieve lost data affecting the flow of hundreds of millions of dollars.

"We want our clients to know today that in spite of this tragedy, all of our businesses are functioning and will continue to function," Morgan Stanley said on its Web site Wednesday. "All our clients should rest assured that their assets are safe...."

Morgan Stanley was the World Trade Center's largest tenant, with about 3,500 employees occupying 25 floors in the towers.

Cantor Fitzgerald, which cannot yet account for about 1,000 employees who worked on the top floors of one of the doomed towers, said it has been coordinating overnight with staff in Los Angeles to get its trading infrastructure in place.

Cantor, one of the biggest bond trading houses on Wall Street, on Tuesday said its technical systems were redundant enough to ultimately come out intact.

BIG TASK, BIG INDUSTRY

Hundreds of people are working closely with major telecommunications and power companies and local authorities to prepare networks for a return to business if securities trading starts tomorrow.

The task is one of the most herculean efforts technicians and logistics officials have ever faced in the United States, and people involved said they have been getting help from big technology companies like IBM Corp. and Microsoft Corp., which have voluntarily come forward to offer aid.

Making the job easier are the precautionary steps companies have taken to assure the safety of their business information. The data storage and protection industry has ballooned in recent years, as companies have come to view continuity of operations as a prerequisite for success.

Makers of back-up and recovery software booked $2.7 billion in revenues last year, and that figure is expected to grow to $4.7 billion in 2005, according to research firm IDC.

"My anticipation is that after yesterday's events that figure may increase," said Bill North, an analyst at IDC.

Still, some World Trade Center tenants have lost data that may be impossible to retrieve. Philadelphia-based law firm Drinker Biddle & Reath LLP, which occupied the 89th floor of the North Tower, lost paper documents related to the securities industry that were not stored elsewhere.

"We are going to have a problem re-creating hard files," James Sweet, the firm's chairman, told Reuters. "We back up all our electronic data every night but you can't replace hard files." He said Drinker plans to replace the lost files by using duplicates held at courts and other firms.

German financial giant Deutsche Bank, which employed roughly 360 people in the World Trade Center complex, said it has already switched operating systems affected by the attack to other locations.

"The bank has successfully transferred its systems and data to back up facilities and is operating according to its existing contingency plans," said Mark Lingnam, a company spokesman, who declined to provide further detail.

Several financial institutions including Morgan Stanley and Merrill Lynch & Co. Inc. have set up temporary offices nearby to cope with the disruption.

"We are working hard on the communication infrastructure in lower Manhattan," said Phil Lynch, chief executive of Reuters America a major provider of information and trading terminals on Wall Street. "What's amazing is amount of help that we are getting from around the world."