Peter Sellars' plans for the new American National Theater, announced officially yesterday, were generally hailed by theater professionals and Kennedy Center board members, although some expressed reservations about its identity as a national theater.

Sellars, the theater's director, and Kennedy Center chairman Roger Stevens have announced a "heavily subsidized" national theater company that would present productions in three arenas: the Eisenhower Theater for major productions of plays, the now largely unused Theater Lab for experimental work, and the Terrace Theater for productions imported from other theaters around the country. The enterprise will be avowedly noncommercial, with ticket prices reduced and pre-Broadway tryouts avoided. Sellars said his intention is to reexamine theater as an art form and change its status on the American cultural landscape. The American National Theater would be budgeted at about $6 million a year, of which at least $2.5 million must be raised from the private sector.

"It's a very important move for theater in this country," said New York producer Joseph Papp, whose Public Theater is in some ways the only similar project in the country. "The most important aspect of it is emphasizing the production for itself and not for the commercial theater . . . It sets the tone for artistic integrity."

Robert Brustein, though, who heads the American Repertory Theatre in Cambridge, Mass., and who, like Papp, has been active in the nonprofit theater movement for more than 20 years, was not so enthusiastic. "I wish him the best of luck," he said. "National theaters are not created at press conferences. There is a national theater and it consists of a network of nonprofit theaters throughout the country . . . I'm very impatient at the biweekly announcement of national theaters -- such announcements seem to be more a contribution to the history of publicity than the history of theater, which is not to say this theater can't become part of the network of interesting theaters around the country."

Peter Zeisler, head of Theatre Communications Group, the umbrella organization for nonprofit regional theaters, was also displeased at the identification of the theater as a national one. "We are not a heterogeneous society," he said. "How do you have a national theater in a culture as ethnically diverse as ours? I wish people would stop talking about a 'national theater.' "

Otherwise, he said, "I think it's really great. I like the idea of five years of research and development. I love him saying that the things we are doing are not working and must be changed . . . not taking as gospel what was true 20 years ago. This is the second wave of the nonprofit theater movement."

Rep. Sidney Yates (D-Ill.), who, by virtue of being chairman of the interior subcommittee of the Appropriations Committee, sits on the Kennedy Center's board of trustees, was equally dubious about the national theater identity. "A number of years ago I asked witnesses before my subcommittee about a national theater and the answer I received was that we already had one through the regional system," he said yesterday. "This country is too big to have a national theater . . . But it's a move in the right direction. The Kennedy Center is moving toward its own fulfilment really. It will become more adventuresome and more of a national guiding spirit."

Board of trustees counsel Harry McPherson echoed the sentiments of many yesterday in placing his hopes as much in Sellars as in the idea of the theater. "He's got the kind of vigor and excited imagination the theater needs," McPherson said. Sellars' presentation to the trustees last week was "very lively," McPherson said. "Holy cats, it costs a lot of money to put plays on. There will be times when we'll be pinched -- as we've always been. But if you're going to be pinched anyway you might as well be trying to achieve something really exciting . . ."

McPherson said he told Sellars after the board meeting that he would have liked to see the late Robert Fitzgerald, renowned for his Greek translations, write a play. " Sellars said, 'Oh yes, I wanted him to turn the "Odyssey" into a play. And I even had the perfect Odysseus. John Belushi!' That convinced me that Peter Sellars has the sort of guts and imagination you've got to have."

Zelda Fichandler, who founded Arena Stage, one of the nation's oldest and most respected regional theaters, issued a statement yesterday from New York, where she teaches several days a week: "Peter's goals for this new theater project are both noble and inspiring. Everyone, I am sure, hopes that the culture at large can provide the means for realizing them. From our three decades of experience, we know the price tag on his dreams will be high, but worth it."

Elsewhere locally, reaction is somewhat tempered by the recent announcement that two of the cities' best smaller theaters, the Folger Theatre Group and the New Playwrights' Theatre, are threatened with extinction. The Folger is scheduled to close June 30, and NPT trustees say it will have to close if it can't raise $250,000 in 90 days. "I don't know if the money needed for the American National Theater will drain funds away from the others," said Howard Shalwitz, artistic director of Woolly Mammoth Theatre Company and head of the League of Washington Theaters. "I hope not."

Daniel Boorstin, who as Librarian of Congress also sits on the Kennedy Center's board, said he liked "the grandeur of the idea. Like all grand ideas, it has its risks . . . I think it will give us a lift, the kind of lift we need."

Board member Bonita Granville Wrather, now in her second 10-year term, agreed. "Outside of Washington people have never really understood that the Kennedy Center is our national performing arts center. This will give us the kind of exposure and prestige we need. We're at a real breakthrough point."

And Liviu Ciulei, who heads the Tyrone Guthrie Theater in Minneapolis and has agreed to serve on the artistic board of the new theater, said, "I think the time is ripe for the birth of an American National Theater . . . There is only one danger: that it gets very official and dusty. But I think we have a good 25 years to wait for that."