A three-judge federal appeals court panel ruled yesterday that the Federal Power Commission acted legally when it raised the price of natural gas found after Jan. 1, 1976, from 52 cents to $1.42 a thousand cubic fast.

The FPC made the ruling last summer and was immediately challenged by a coalition of consumer lobbies, labor unions, legislators and others. The groups charged, among other things, that the near tripling in rates was unreasonable.

The Federal Power Commission regulates the prices natural gas producers can charge for gas that is discovered in one state and consumed in another.

The three-judge panel ruling was unaimous, although Judge Charles Fahy dissented on one issue. The other members of the panel were Harold Leventhal and Gerhard A. Gosell.

The FPC raised the price for newty discovered natural gas as a spur to exploration. The amount of natural gas committed to the interstate market has been shrinking in recent years, in large part because producers can receive substantially higher prices in the uncontrolled intra-state market.

Ellen Berman of the Consumer Federation of America, one of the many organizations challenging the FPC decision, told the Associated Press she was "flabbergested and stunned" and said the groups may appeal to the Supreme Court.