The Federal Communications Commission yesterday ladled out portions of the desirable but dwindling radio frequency spectrum to police and fire departments, cellular radio companies and users of private two-way radio.

The allocation of frequencies on the most desirable part of the radio spectrum became controversial in recent months because 12 U.S. communications companies and Canada had sought to use some of the spectrum to launch a national mobile satellite service to serve the emergency and commercial needs of rural areas. But U.S. public safety groups representing police and fire departments had argued that radio frequency congestion in urban areas -- such as Washington -- made it imperative they receive the spectrum.

The FCC voted 4 to 1, with Commissioner James H. Quello dissenting, to leave no room for mobile satellite service on the most desirable spectrum, mainly because of the immediate needs of public safety agencies.

"The Congress has directed that we prioritize public safety," said Commissioner Dennis R. Patrick. "The bottom line is those needs are very dramatic, indeed."

There still will be shortages in available radio spectrum for public safety needs, he said. Radio spectrum allocated yesterday for public safety uses will be held in reserve until a nationwide plan allowing individual public safety systems to communicate with adjacent systems is devised.

The FCC did assign space for new mobile satellite service on the less-desirable higher frequencies. Those services were pioneered by the National Aeronautics and Space Administration.

Hughes Communications Inc. -- a subsidiary of Hughes Aircraft Co. that had applied to provide the mobile satellite service -- NASA and the Canadians have said that having to adapt technology to higher radio frequencies could make the service too expensive to offer.

Glyn Berry, first secretary of the Canadian Embassy, said yesterday that the service was vital to Canada so it could provide communications in its vast rural stretches, thereby stimulating the timber, offshore oil, and mineral industries. "Our position is we are not giving up on this one," he said.

The Canadian government has requested intervention of the State Department over the FCC decision.

According to Jerry Freibaum, a NASA spokesman, the FCC was successfully lobbied by some public safety and business users and by Motorola Inc., which dominates the existing two-way communications equipment market. But the new satellite technology would have been the only means to provide nationwide contiguous communication between any two points.

While Motorola said it had no objection to mobile satellite service, the company argued that public safety agencies should get first priority to expand existing ground systems. There is currently no need among public safety agencies for a satellite-based long-distance radio system, but a need to coordinate systems at the local level, said John D. Lane, a lawyer representing public safety agencies. "Who needs to get to a satellite to talk to a guy across town?"