Five laptop computers were stolen from Towers Perrin's Manhattan offices late last year.
The computers contained personal information about employees of several of the consulting firm's clients. One of the firms was Altria Group Inc., New York, said Lisa Gonzalez, an Altria spokeswoman. The theft compromised personal data such as pension-related salary information, names, birth dates, Social Security numbers and hire dates of nearly 18,000 former and current employees, she said.
Dewayne Rivers, a former Towers Perrin employee, was charged with grand larceny in the case, said Edison Alban, a spokesman with the New York County District Attorney's office, which is conducting the investigation. Mr. Rivers' personal computer was confiscated as part of the investigation.
Mr. Rivers worked for more than four years at Towers Perrin and resigned just 10 days before his arrest on Dec. 28. Joseph Conway, a spokesman for the Stamford, Conn.-based firm, said Mr. Rivers worked as a "junior-level administrative person."
Mr. Conway declined to identify any of the clients because of the ongoing investigation. He said all the affected employees have been informed about the situation, and Towers Perrin is offering the employees free credit monitoring. Towers Perrin is not aware of any cases of the information being misused.
(updated with correction)