The American Ballet Theatre and the Kennedy Center today canceled ABT's four-week December season in Washington. The announcement came shortly after the dancers, who were locked out by ABT's management Sept. 2, met to hear their leaders warn of a long dispute that could result in the cancellation of ABT's entire 1982-83 season.

The ABT has already canceled its Paris and Boston engagements, but chose not to cancel its January visit to Miami Beach -- a cancellation ABT earlier had threatened for today. Instead, ABT said, it will reassess that engagement Nov. 1.

ABT was scheduled to perform at the Kennedy Center from Dec. 7 to Jan. 2 and to present the world premiere of its new full-length production of "La Sylphide."

Kennedy Center Chairman Roger Stevens said the cancellation was made now because ABT no longer had sufficient time to properly rehearse for the engagement. He said he is considering a number of replacements -- including the possibility of opening "Show Boat" earlier than its currently scheduled Jan. 5 premiere at the Opera House.

There has also been talk that the production of "On Your Toes" might be moved from the Eisenhower Theater into the Opera House, but Stevens said no such plans were now under discussion. The Kennedy Center said it will offer tickets to "On Your Toes," a revival of the 1936 musical by George Abbott and George Balanchine, in exchange for subscribers' ABT tickets.

"We will know in two or three weeks" what will replace ABT, Stevens said. He said the Kennedy Center has nothing specific in mind at the moment, but the replacement definitely will not be a dance attraction. Dance companies make their commitments too far in advance, Stevens said. "It will be most likely a drama or possibly a musical; that's all we could put together in a hurry."

The ABT cited a lack of time to market its tickets and a need to give the Kennedy Center time to find a replacement attraction as its reason for announcing the cancellation.

Earlier today ABT's dancers and their union -- the American Guild of Musical Artists -- filed an unfair-labor-practice charge with the National Labor Relations Board against ABT. The complaint stems from ABT's refusal to open its books to the dancers after allegedly claiming it lacked the money to grant the increases sought by the dancers. Under current interpretations of the National Labor Relations Act, an employer who claims he cannot afford to meet union demands is required to show it by opening his books.

When the latest round of negotiations began last Friday, the ballet company's management and the dancers were approximately $1.3 million apart on money issues. When those negotiations broke off Saturday -- with no new talks scheduled -- the two sides were only about $344,000 apart for the entire three-year term of a proposed new labor contract. All but $86,000 of the concessions made during the weekend bargaining, according to a spokesman for the dancers, were made by the performers.

ABT and its dancers were still far apart on a number of work-rule and job security issues and made no progress in those areas, according to Frank Smith, spokesman for the dancers.

The dancers, in a public statement, today asked, "How is it that a world-renowned dancer like Mikhail Baryshnikov ABT's artistic director can ignore his dancers and refuse to speak out or become at all involved in this dispute? . . . Management seeks to starve us out."

The dancers' statement also charged several ABT administrators, including Baryshnikov, with "time-worn, old-line, union busting techniques . . ."

Baryshnikov, in a prepared statement, responded, "It is not a function of an artistic director to negotiate labor contracts . . . however, I did urge the ABT board of directors to guarantee the dancers a substantial increase . . . totaling over $1.3 million . . ."