The employee appears to have stolen data from some of the company's contact lists, the company says. SunTrust is already informing impacted clients and is working with outside experts and coordinating with law enforcement on investigations.

The stolen information includes names, addresses, and phone numbers, along with certain account balances, as this was the data included in the contact lists, the company confirmed.

Personally identifying information such as social security numbers, account numbers, PINs, User IDs, passwords, or driver's license information wasn’t included in the lists.

“We apologize to clients who may have been affected by this. We have heightened our monitoring of accounts and increased other security measures. While we have not identified significant fraudulent activity, we will reinforce our promise to clients that they will not be held responsible for any loss on their accounts as a result,” Bill Rogers, SunTrust chairman and CEO, said.

Rogers also underlined that the company is focused on protecting its customers and that it is determined to help all SunTrust clients to combat the increasing concern about identity theft and fraud. SunTrust is now offering Identity Protection for all current and new consumer clients, the company announced.