The Alexandria prosecutor, the chief of police, the Alexandria Mental Health Center and other city agencies have concluded that a proposed ordinance banning the display of magazines like Playboy and Penthouse is not necessary in the city.

The Alexandria City Council requested last October that City Attorney Cyril D. Calley study the possibility of passing an ordinance like the one now in effect in Fairfax Country. Under the law, sexually explicit publications must be placed under the counter or have their covers shielded from view.

Although Calley made no specific recommendations to the City Council last night, his report said that the city agencies concerned with the issue feel that voluntary compliance among vendors to regulate the display of sex oriented publications would have the same effect as an ordinance.

Calley said the city is asking vendors to regulate themselves and he said the response has been excellent thus far.

In a letter to Calley, Commonwealth's Attorney William L. Cowhig said that in the past grand juries have refused to indict dealers for selling national publications. "Until there is a resentment by the general public to the distribution of these materials, it is my opinion that a 'cover-up' ordinance will not decrease the sale" of the magazines.

In an interview, Cowhig said publications like Penthouse should be banned. But he said the way to do that is to let people know what is in the magazines.

"As far as I'm concerned they ought to be opened up to the centerfold and placed over the counter so that everybody will know what kind of trash is being sold in the city," said Cowhig.

Peggy Errington, the chief clinical psyschologist at the Alexandria Community Mental Health Center, wrote Cally that "there is no definitive research that indicates exposure to the sight of sexually explicit photos is a significant factor "in the development of psychological and behavioral problems among young people.

Alexandria Police Chief Charles T. Strobel said that because voluntary compliance by retailers seems likely, there is no need for the city to pass an ordinance. Strobel said the only action necessary at this time would be a Council resolution outlining the city's policy on the display of sexually oriented publications.

Calley said he had talked with the Fairfax authorities and had concluded that their action was mostly "political" because magazine vendors in the country previously had agreed to voluntarily adhere to the regulations now in the ordiance.