Ameriprise Financial, a recent spin-off of American Express, has notified more than 150,000 customers and more than 65,000 financial advisors of a potential data breach.
The company says a laptop computer containing sensitive personal information was stolen from a car in December.
The location of the city in which the theft took place was not divulged and the company isn't saying who the employee was. Company officials said the case is still under investigation.
The company says it does not believe the thief targeted the car in order to steal the data. Officials say the vehicle was not parked in an Ameriprise parking lot, and there was nothing to identify the vehicle as belonging to an Ameriprise employee.
A spokesman said the data on the laptop is not readily available to the casual user because the software program is password protected.
However, Ameriprise concedes the data containing the sensitive information was not encrypted, as required by company policy. It was also left unexplained why a computer containing so much sensitive data was left in an employees personal vehicle.
Officials say one of the files on the computer contained only the names and internal Ameriprise account numbers of 158,000 customers. The second included the names and Social Security numbers of 68,000 Ameriprise advisers.