The U.S. Court of Appeals has set a tougher standard of proof that the Federal Communications Commission must meet when it moves to revoke a broadcaster's operating license.

In a decision involving a Beaufort, S.C., radio station, the court ruled facts in a case warrant a revocation order. The traditional standard in civil and administrative proceedings is the lesser requirement that an action be supported by a "preponderance of evidence."

The commission had argued that broadcasters have a special status as public trustees of a scarce resource -- broadcast frequencies -- and owe the public a high duty of care in exchange for that privilege. The commission argued that a higher standard of proof would "significantly burden" its efforts to further the public interest through enforcement of FCC regulations.

The late Judge Harold Leventhal, writing for the court, said the commission's decision to revoke a license is similar to action by the Securties and Exchange Commission in revoking a broker's license, where the higher standard of "clear and convincing" evidence is applied.

The commission argued that the loss of a broadcast license does not amount to a potential for loss of livelihood, as in the broker's case. Leventhal, however, disagreed.

"The broadcaster who loses his license may get other jobs in the industry, but he certainly has lost a business," Leventhal wrote.

Moreover, Leventhal said, while a broker has an "expectation" of business, a broadcaster has a "security of interest" or right to a license during its term. FCC broadcast licenses are issued for a three-year period.

Leventhal noted that the court was not suggesting that the higher standard of proof be required in all revocation cases that come before the commission. There are many cases, such as those involving citizen band licenses, where no loss of livelihood is involved, Leventhal said.

The court's decision, issued Jan. 14, upheld the commission's order that revolked Sea Island Broadcasting Corp.'s license to operate AM radio station WSIB in South Carolina. The court said the commission's decision would have met the higher standard of proof now required.

The FCC has not yet decided whether to ask the full appeals court to review the proof question or whether to take the case to the U.S. Supreme Court.

Leventhal was joined in his decision by Judge Spottswood Robinson and by U.S. District Court Judge Charles R. Richey, who sat on the appeals panel by designation.