BOOK CRITICS CIRCLE ANNOUNCES '81 AWARDS

The first book awards of 1981 were announced yesterday as the National Book Critics Circle picked the ''most distinguished'' books written by Americans last year in four categories. It was the closest voting in the six-year history of the organization of professional critics and editors.

The winners are: Fiction - ''The Transit of Venus'' by Shirley Hazzard (Viking/Penguin). Miss Hazzard, a novelist, essayist and critic, is the author also of ''The Bay of Noon'' and of writings about what she perceives as the ineffectiveness of the United Nations, where she worked 10 years.

General Nonfiction - ''Walter Lippmann and the American Century'' by Ronald Steel (Atlantic/Little, Brown). Mr. Steel, also author of ''Pax Americana,'' has frequently written on foreign affairs.

Poetry - ''Sunrise'' by Frederick Seidel (Viking/Penguin). Among Mr. Seidel's other books of poetry is ''Final Solution.'' Criticism - ''Part of Nature, Part of Us: Modern American Poets'' by Helen Vendler (Harvard University Press). Miss Vendler, whose books include ''Extended Wings: Wallace Stevens' Longer Poems,'' teaches English at Boston University.

In the field of the novel, it took four formal ballots before Miss Hazzard was pronounced winner by the deadlocked critics. E.L. Doctorow, author of ''Loon Lake,'' was ahead on the first trial ballot, but in the final vote William Maxwell's ''So Long, See You Tomorrow,'' emerged as the runner-up. Other Vote Difficulties

The general nonfiction category -which most critics regarded as stronger than fiction this year -caused even more controversy. After six ballots, the runner-up title after Mr. Steel's biography was ''Alice James: A Biography,'' by Jean Strouse.

The voting for best book of poetry also was deadlocked through four ballots. On the fifth formal vote, Mr. Seidel's book won, closely followed by James Merrill's ''Script for the Pageant.''

Only in the award for criticism was Miss Vendler's book the clearcut choice from the beginning, according to Eliot Fremont-Smith, The Village Voice critic, who is chairman and president of the organization. He presided over the four-hour meeting of the 18 members of the board of directors present at the Alqonquin Hotel. 300 Members

This year, no special Board Award was given to a writer. Last year, the honor went to Flannery O'Connor.

The National Book Critics Circle, which has 300 members, has what it considers a democratic method of selecting the prize-winning books. The entire membership elects up to three books in each category by mail ballot and the board of directors determines the remainder of the nominations and makes the final selections.

The two-fold aim of the organization is to raise standards for the profession of book criticism and enhance public appreciation of quality literature. The winners will receive scrolls at an invitational ceremony on Jan. 22 in the Time-Life auditorium.