In a defiant assertion of artistic freedom, a group of the Soviet Union's most prominent and established writers have organized a new, unofficial literary magazine aimed at relaxing the tight control of the state over the arts.

The writers hope their new creation, called Metropol, will be officially published, but events surrounding their efforts to announce its existence publicly in recent weeks indicate they have embarked on a perilous course that could result in serious reprisals by the authorities, who maintain strict constraints on literature.

The literary works in Metropol are essentially apolitical. But many of them violate the rules of Soviet censorship, including explicit sexual references and descriptions that never appear in Soviet literature. Officially forbidden themes range from those dealing with the existence of an immortal soul to outspoken criticism of government controls on the arts.

One of the most surprising aspects of Metropol's appearance is the collective nature of the enterprise. While lonely acts of protest are not unusual, a joint effort of this kind of prominent Soviet literary figures is unheard of in the post-World War II period.

The 23 authors include two of the Soviet Union's best-known contemporary poets, Andrei Voznesenski, who has just been awarded a State Prize for Literature, and Bella Akhmadulina, whose works sell out instantly upon publication. Others linked in the unusual effort are Vassily Aksyonov, one of the country's most popular prose writers, and Vladimir Vysotsky, a prominent and popular Moscow actor and nationally acclaimed songwriter.

An attempt today by the writers to announce Meropol and discuss their intentions at a reception at a small cafe on a quiet back street in central Moscow was thwarted when authorities abruptly closed the cafe last night, allegedly for sanitary reasons. It was the latest example of intense official efforts to quash any public moves by the writers to call attention to their efforts.

Nevertheless, two of the new magazine's 12 painstakingly typed copies have reached the West and news of the existence of Metropol has circulated in the tightly restricted Moscow literary community in recent months.

None of the contributors can be considered a dissident. On the contrary, they are writers whose works have been published and officially praised inside the Soviet Union for many years. Voznesenski, for example, recently appeared on national television reading his poems, the kind of literary event doted upon by millions and hailed by the authorities as an example of the advanced status of creative artists here.

The fact that he and the others have participated in the production of an unofficial "almanac," as they call it, that is contemptuous of official cultural policies makes the appearance of Metropol particularly embarrassing for Soviet officialdom and particularly exciting for Moscow's intellectuals.

It was understood that several of the writers were called in recently by the Writer's Union, in which membership is mandatory for any hope of authorized publication, and bluntly warned that Metropol could be an embarrassment for the Soviet Union at a time when the Kremlin is seeking final agreement with the United States on a new strategic arms limitation treaty.

Nothing in metropol directly confronts the Soviet authorities. But the entire volume -- which reached the United States earlier this month -- is an implicit challenge.

If there is any theme that unites all the work, according to two American scholars who have read through the copy reaching the United States, it is a recurrent plea for artistic freedom.

A prefatory note from Metropol's editors, of which five are listed, explains that Soviet cultural life "suffers from something like a chronic ailment which might be defined either as 'hostility to differentness' or simply as 'fear of literature.'"

"Because of the nauseating inertia which exists in our literary journals and publishing houses," the preface states, much important literature can be "doomed to many years of wandering and homelessness" -- meaning that it does not get published. Metropol, the editors explain, was born to provide a home for such literature.

The preface states -- and several authors published in Metropol reiterate -- that writers alone should be responsible for what they write, an assertion that defies the elaborate ideological and bureaucratic controls on all forms of creative endeavor here.

But the editors of Metropol have reportedly decided to offer their journal -- in Russian literary circles the characterization "almanac" signals irregular appearances -- to the Soviet Ministry of Culture's "publications department" and to official publishing houses. As if to respond in advance to any suggestion that they might be bitter or angry, the editors state that their journal "is a healthy child and its authors are all in good moods." The birth of Metropol "is a holiday for everyone," they declare.

The "holiday" has been carefully prepared. Copies of Metropol are already in the hands of publishers in the United States and France and editions in Russian, French and English are planned in the near future.

The Russian edition will be published by Ardis, an independent publishing house in Ann Arbor, Mich., specializing in Russian language. books and works of Russian literature. Prof. Carl Proffer of the University of Michigan, who runs Ardis with his wife, Ellendea, said in an interview that a Russian edition will appear this spring in about 2,000 copies. He said this is a sizable number in the specialized field. Ardis, a small but highly regarded house, also will arrange for an English translation of Metropol.

Proffer declined to say how he acquired his copy of Metropol. He estimated the journal totals 250,000 words, which could mean a book of more than 500 pages.

In effect, Metropol's contributors decided not to put up with an old Soviet tradition of writing some things "for the drawer," knowing they would never appear in print.

There are unconfirmed reports that some writers who were approached about contributing to Metropol declined, perhaps fearful of repercussions. But a substantial number of well-known figures did contribute. Metropol also includes a passage by John Updike, from his newest book, "The Coup." Updike is one of a number of modern American writers, some of whose works are officially lauded here.

Among the Soviet writers of note are these:

Fasil Iskander, an inventive, humorous writer, many of whose works are set in the Trans-Caucasus. Although much of his writing has been subjected to censorship, Iskander has a wide following and an excellent reputation among Soviet intellectuals. Some of his works have been published in the West.

One of the two Iskander stories in Metropol is called "A Very Sexy Little Giant." Its hero, an undersized lover named Marat, recounts a series of amorous adventures, each ending, "She was so satisfied, so satisfied."

At one point Marat suffers from temporary impotence after being interrupted at a crucial moment with the mistress of Lavrenty Beria, Stalin's last police chief. Marat overcomes the fear engendered by that experience with therapy provided by a woman who trained boa constrictors.

Akhadulina, a much-admired poetess who contributed a dense and complex prose piece.She was once married to Yevgeni Yevtushenko, who with Voznesensky is the best-known of modern poets. Yevtushenko is not represented in Metropol, a fact that will bring knowing nods to detractors who feel he is too close to the authorities, but which could also be a function of Moscow's arcane literary politics.

Fridderich Gorenshtein, a screenwriter, who wrote two of the most interesting Soviet films of recent years, "Solaris" and "Love Slave." In Metropol, Gorenshtein writes a story about a 46-year old man who is slowly going insane, passing into a Dostoyevskian, metaphysical madness. The hero comes closer and closer to Christianity, but at the end is taken off to a mad house. According to Prof. Proffer, the story has strong echoes of 19th century Russian literature.

Aksyonov, famous to several generations of Soviet young people though he is still in his forties, is listed as the first of the five Metropol editors. His contribution is a play called "The Rour Humors," an experimental work that pokes fun at cliches of official Soviet culture.