SAN FRANCISCO — The U.S. Court of Appeals for Ninth Circuit has granted en banc review in a case dealing with the Federal Trade Commission's authority to regulate the mobile phone industry.

The Ninth Circuit on Tuesday vacated a three-judge panel decision which had sided with AT&T Mobility LLC in its fight with the agency over the company's practice of slowing down data service, known as data-throttling, for customers with unlimited data plans. Under Ninth Circuit rules, the case will now be reheard by an 11-judge panel of the court after a majority of the active judges voting to grant the FTC's request to take the case up en banc.

The now-vacated panel decision found that AT&T's status as a common carrier shielded it from an enforcement action brought under the FTC Act. The ruling reversed a decision from U.S. District Judge Edward Chen of the Northern District of California who found that the Act's exemption for common carriers didn't apply to non-common carrier activities such as data service.