The La Jolla Playhouse in Southern California and the American National Theater will exchange productions in this year's "AT&T Performing Arts Festival at the Kennedy Center."

The festival, which will be officially announced today in La Jolla, is designed to give wider exposure to regional theater companies and emphasize the national scope of the American theater. Last summer, four productions from Chicago played the Kennedy Center under the program.

"Shout Up a Morning," a musical based on the legend of John Henry, will open at the La Jolla Playhouse on June 1 and then have a Washington engagement beginning July 15. ANT's contemporary treatment of Sophocles' "Ajax," scheduled to premiere at the Kennedy Center on June 7, will move to La Jolla on Aug. 31.

"This kind of tying together of two extremes of American theater -- geographically and in a sense artistically -- is a central mission of an American national theater," said ANT Director Peter Sellars yesterday. "ANT now has a beachhead on both coasts."

This year, AT&T will contribute approximately $350,000 to cover the costs of moving both shows. Another $350,000 will be targeted for television and print advertising, especially in Southern California.

"Shout Up a Morning," which tells the story of the fabled railroad worker who lays track faster than a steam engine, has a score by the late Julian (Cannonball) Adderley and his brother Nathaniel. It will be directed by Des McAnuff, artistic director of the La Jolla Playhouse since 1982. Sellars is staging "Ajax," which, in the adaptation of Robert Auletta, takes place on the steps of the Pentagon after an American military victory in Latin America.

The La Jolla Playhouse, founded as a summer theater in 1947 by Gregory Peck, Dorothy McGuire and Mel Ferrer, has undergone a significant transformation in the past few years. In 1984, it premiered an early version of the Tony-winning musical "Big River," while last summer Stephen Sondheim worked with the company on a revised production of his Broadway flop "Merrily We Roll Along." The playhouse's inaugural production under McAnuff's leadership was Bertolt Brecht's "The Visions of Simone Machard," staged by Sellars.

"We see ourselves as a place where leading theater artists can come work in the summer," said McAnuff. "This festival is a great opportunity for us to reach a national audience."