A federal appeals court in Washington on Friday took a shot at the Federal Communications Commission when it tossed a rule that barred any single cable television operator from serving more than 30 percent of all subscribers. Cable operators, including Comcast Corp., had argued that the restriction blocked their ability to make efficient acquisitions.

In the closely watched case, the U.S. Court of Appeals for the D.C. Circuit held that the FCC had not shown that allowing a cable operator to serve more than 30 percent of subscribers risked reducing “either competition or diversity in programming.” The judges noted in the opinion that there is increasing competition among satellite and fiber optic video providers and that there has been a “dramatic increase” in the number of cable networks and programming.