Charter Communications is dropping plans to track the Web use of some high-speed Internet subscribers, citing concerns raised by its customers.

In May, Charter announced a pilot program in four markets aimed at producing enough information for advertisers to target online ads for individual customers based on their viewing habits.

But Charter officials say Tuesday that some customers have raised concerns, so the company has decided not to move forward with the pilot program.

The plan drew criticism from some privacy advocates and from two members of Congress who wrote to Charter CEO Neil Smit last month, urging him to reconsider.

The pilot markets were San Luis Obispo, Calif.; Fort Worth, Texas; Oxford, Mass.; and Newtown, Conn.

The trial used technology from NebuAd, a Redwood City, Calif., online advertising company.