NEW YORK (Reuters) - Express Scripts Inc <ESRX.O> said on Tuesday a "small number" of its clients have received letters threatening to expose customers' personal information, an apparent connection to an earlier extortion threat made against the company.

The large U.S. pharmacy benefit manager said last week it received an extortion letter threatening to expose millions of patient records and warned of a "potential large data breach."

The letters sent to its clients are similar in form to the one received by Express Scripts in early October from an unknown person or persons. Express Scripts clients are employers, unions, governments and other pharmacy plan sponsors.

An Express Scripts spokesman declined to specify further how many clients were threatened.

The company announced a $1 million reward for people who provide information resulting in the arrest and conviction of those responsible.

The St. Louis-based company, which handles about 500 million prescriptions a year, also said it would offer free identity restoration services to victims of identity theft because from this incident. It has contracted with risk-consulting firm Kroll to assist victims.

"Express Scripts recognizes that this situation is concerning to our clients and members," CEO George Paz said in a statement. "We want to assure them that they will have our constant support until their issues are resolved."

The letter sent to Express Scripts contained information on 75 customers, including names, dates of birth, social security numbers and, in some cases, prescription information.

Express Scripts would be the latest company to face a major data breach in recent years, following discount retailer TJX Cos <TJX.N> and Bank of New York Mellon Corp <BK.N> among others.

Express Scripts said on Tuesday it is not aware of any actual misuse of its customers' data.

Express Scripts said last week it immediately notified the Federal Bureau of Investigation, which is investigating. An FBI spokesman in St. Louis said last week the agency was contacted by Express Scripts but the spokesman could not comment on whether a probe had begun.

(Reporting by Lewis Krauskopf; Editing by Tim Dobbyn)

Publié le 11 novembre 2008 Copyright © 2008 Reuters