Paris — Turn the FM dial here and a cacophony of sounds competes for the listener's ear. There is news in Portuguese, wailing love songs in Arabic, prayers in Hebrew - or just plain jazz, rock, or classical music.
In a nation where the government has traditionally monopolized broadcasting and served up predictable fare, the so-called radio libres (free, or nongovernment-owned, radio stations) provide unprecedented variety. Since the ''liberation'' of the airwaves after the Socialists came to power in May 1981, free radio has attracted the ears of an estimated 1 million Parisians alone.
But the new free radio stations are now being threatened by their own success. Too many stations are competing for a limited number of frequencies. As the government attempts to sort out the anarchy, the larger, better-organized stations are threatening to squeeze much of the present diversity out of the broadcasting.
''This government gave us our liberty,'' said Jean de Carroir, president of the National Federation of Free Radio Stations. ''But it is now taking it away.''
The problem is that there are only 22 FM bands for the Paris region, yet 156 operating stations or proposed stations. Officials will turn down the petitions of some 93 stations. The remaining 63 must then combine to form 22 stations.
The plan has set off a chorus of protests from the stations that are going to be eliminated. And the protests - especially when the ax hits devoted interest groups - have made much noise. The Communications Ministry, for example, originally attempted to close down one round-the-clock station aimed mainly at the homosexual community, but after thousands of listeners deluged the ministry with phone calls, letters, telegrams, and a protest in the Place de la Concorde, officials relented.
Radio Solidarite has not fared so well. Like its mother, the Free Polish Union, the free Paris station has been banned. Despite a hunger strike by the staff, which ended recently, the voice of the Polish worker has not been allowed back on the air.
When the final list of approved stations is published sometime in the first half of April, more protests are expected.
''We will have some problems,'' said Pascal Vallery-Radot, a director of the Communications Ministry committee charged with regulating FM. ''But we can't satisfy everyone. If necessary, the police will intervene and arrest the broadcasters and seize the equipment.''
But before equipment is seized, many free broadcasters may be forced to sell their equipment to creditors. The reason for their financial difficulties: They are not allowed to sell advertising. Ads were banned on FM after local newspapers screamed that they would lose their advertising revenues.
''It's disgraceful,'' said Lynn Guez, a disc jockey for Radio Gilda. ''None of us gets paid and still the station has no money.''
The government recognizes the problem, and says it is ''studying'' the possibility of permitting the stations to go commercial. But the regional newspapers remain adamantly opposed, so the study could continue indefinitely.
For the time being, the government is offering state aid to help ease the stations' financial woes. Many stations, though, are refusing to take the money.
''It's even a worse idea than forbidding advertising,'' said Guez. ''What's a free radio station subsidized by the government?''
But without subsidies, many free radio stations say that municipalities, political parties, and the entrenched written press will soon dominate FM. Already, most national parties and press organs have found that the publicity of running a radio station more than makes up for its operating losses.
''We could soon be facing the worst possible situation,'' said De Carroir of the Free Radio Federation. ''No publicity, no subsidies, and only the established powers on the air.''
To prevent this, he wants the government to ban all transmitters with a range greater than 30 kilometers (19 miles). And he wants municipalities banned from owning their own stations.
''If this isn't done, the free radio stations will just turn into France Inters (the state AM radio),'' he said. ''Free radio stations must continue to exist to give a voice to all the groups who aren't usually heard.''