Tue Apr 12, 8:56 PM ET

NEW YORK - Some 310,000 people could have lost their personal identification data to online thieves who broke into the computers of leading US information broker LexisNexis, the company said.

The number was nearly 10 times that reported when the computer break-in was first revealed a month ago by the company, a subsidiary of the Anglo-Dutch publishing group Reed Elsevier.

On March 9 LexisNexis announced that thieves using stolen passwords had penetrated the computer files of its recently-acquired Seisint unit, obtaining information on the accounts of approximately 32,000 customers.

However, on Tuesday the company conceded that data files for as many as 310,000 people had been illegally accessed in 59 separate incidents.

Seisint sells information on individual consumers to businesses to help them avoid credit card and insurance fraud. It also provides similar information and database services to law enforcement agencies.

The information obtained included names, addresses, social security and drivers license numbers, which can be used by identity thieves to fraudlently get access to bank accounts and credit cards and other sources of money.

The case was the second large theft of personal information this year involving US companies in the highly lucrative business of gathering and selling consumer financial data to other companies.

In February swindlers in Los Angeles duped ChoicePoint, the country's largest such business, out of sensitive personal information on 145,000 individuals.

The information thefts and an explosion in identity theft cases have resulted in a number of proposals in federal and state to place controls on the consumer financial data industry.

"These companies are playing Russian roulette with the personal information and identities of millions of Americans," said Representative Ed Markey in March after the original LexisNexis theft announcement.

On Tuesday LexisNexis said in a statement it would offer free support services to all those whose personal information was taken to protect them from possible identity theft-related fraud.

"We are taking action to notify individuals where we found some indication that they might have some risk of identity theft or fraud, even if that risk did not appear to be significant," said Kurt Sanford, chief executive of the LexisNexis' Corporate and Federal Markets division.