"How Chile Muzzles Its Press" {Outlook, Jan. 3}}, written by Sanford J. Ungar, dean of the School of Communications at American University, reflects well the communication problem which Mr. Ungar must have had in Chile. He established good communications with one sector of the political opposition and decided to plead their case in the United States.

His article, therefore, refers to the press in Chile as perceived from that particular viewpoint. His method is simple: he takes two legal cases involving journalists and generalizes therefrom. His view is, therefore, a legitimate perspective, but clearly biased and incomplete.

The fact of the matter is that of the five national newspapers that circulate in Chile, two, which were legally authorized last year, belong to opposition groups. In addition, there are almost 10 weekly newsmagazines and more than 30 radio stations that also belong to or are affiliated with the opposition.

Most foreign observers who visit Chile are impressed by the diversity and the highly critical content of the opposition press. Moreover, they often recognize that journalists in Chile are more outspoken than in many Latin American countries, including those in some of the formal democracies that today are the darlings of the liberal left.

In fact, the United Nations Special Rapporteur for Human Rights in Chile, former Costa Rican foreign minister Fernando Volio, has recognized the breadth of the Chilean spoken and written media which certain opposition spokesmen, in his own words, "habitually utilize for extremely harsh criticism occasionally bordering on the grotesque."

This is why, regardless of how many excuses are made by the Chilean Christian Democrats and Socialists for the failure of their press publications, the relevant fact is, simply, that Chileans do not buy their papers, a fact which suggests less popular support than what they claim abroad.

By the end of his article, Mr. Ungar even attempts another excuse on their behalf: "political apathy." Let's be serious, sir. Chileans don't buy La Epoca and Fortin Mapocho because politically and economically they represent precisely what is outdated in our country: socialism and demagoguery.

HERNAN FELIPE ERRAZURIZ Ambassador of Chile Washington