Federal Communications Commission officials said yesterday that they were reiterating their standing rules Wednesday when they sent an advisory to amateur or "ham" radio operators and commercial broadcasters that the amateur frequencies could not be used for active newsgathering.

The advisory was sent when administration officials were still refusing reporters permission to go to the Caribbean island of Grenada, invaded by U.S. forces early Tuesday morning. Four reporters encountered on the island by U.S. troops Wednesday were airlifted to the carrier USS Guam.

Under the circumstances, amateur radio was the only available independent source of information from the scene of the invasion.

"The commission was not shutting down some 'loose end' here that was violating a blackout," said Ray Kowalski, chief of the FCC's special services division. "The commission was using, as much as it could, amateur radio to facilitate communication within the amateur rules."

The rules involved, in effect informally for years but codified only last July, prohibit the use of amateur frequencies for "business communications on behalf of any party."

In an official notice July 20, the FCC explained: "For example . . . an amateur radio station may not be used for a medical or law enforcement communication which does not fall within the exception of immedate danger to life or property." Many other frequencies are available for this purpose, it said.

The notice made no specific mention of newsgathering. Under the FCC's interpretation, reporters legally may monitor amateur broadcasts, but interviewing, either directly by reporters or indirectly by ham operators relaying reporters' questions, represented a prohibited "business" use of the airwaves.

The notice was issued Wednesday, Kowalski said, because dozens of commercial radio and television broadcasters were requesting permission to use a normally restricted frequency that was being used by an American medical student on Grenada. The student, Mark Barettella, broadcast for about 36 hours from his dormitory at the St. George's University School of Medicine on Grenada.

Kowalski said that because of an urgent request from the State Department Tuesday night, he allowed Barettella and at least three U.S.-based hams to use a frequency normally restricted to communications in international Morse code. But he and other FCC officials repeatedly denied news organization requests to communicate with Barettella.

According to Kowalski and a CBS spokesman, CBS News made such a request Tuesday night and again Wednesday, asking permission to patch Dan Rather, anchorman of the "CBS Evening News," into the amateur frequency so he could conduct an interview with Barettella.

Asked for comment on the FCC interpretation of newsgathering as business, a CBS spokesman said, "We would agree this was not the kind of use for which the amateur frequencies were intended." Asked if the agency should have made an exception for the Rather interview, CBS responded that while the request was "not an emergency, it would have hurt no one and the American people would have been better informed."

Earlier Tuesday, the State Department had intervened on Barettella's behalf, asking the FCC to let him use a normally restricted frequency, according to Kowalski. "I gave the waiver based on what I was told by the State Department was a life-and-death emergency," Kowalski said.