SAN FRANCISCO -- A federal appeals court has rejected a legal challenge seeking to bar a California regulation to reduce greenhouse gas emissions by forcing automakers to make less polluting fleets of cars sold in the state.

The U.S. Court of Appeals for the District of Columbia on Friday rejected the lawsuit filed by the U.S. Chamber of Commerce and the National Automobile Dealers Association, which argued that the U.S. EPA should not have granted the state a waiver for its clean car program.

A three-judge panel ruled the chamber failed to identify any members affected by the regulation, and that the dealers' association failed to prove its members would suffer future harm.

Further, the court found that automakers, not dealers, are regulated under the program.