As an actor, Larry Shue has suffered his share of disappointments and rejections. Imagine the incongruity, then, of his recent predicament: Three different producers wanted to mount each of his three plays in different cities at the same time.

"The night before 'The Nerd' opened in London, I got a call from the producers that one of the leads in 'The Foreigner' in New York had been fired and they wanted me to take over the part," he says. "But I was supposed to go to Milwaukee for rehearsals of 'Wenceslas Square.' So for a while I flew back and forth between New York and Milwaukee."

"The Foreigner" is now playing at Olney Theatre, but not with Shue in it. He is now playing the lead in the New York production, which recently won two Obie Awards and the Outer Critics' Circle Award for best new American play off-Broadway. "The Nerd" opened in London last October and has become, according to the playwright, the highest grossing West End hit of the season.

Ten years ago Shue was working at the Harlequin Dinner Theater, playing leads in some shows and carving roast beef on the side. A trip he took to Prague with Harlequin director Nick Howey became the inspiration for his first full-length play, "Wenceslas Square." Howey had written a master's thesis on the development of Czech theater after the Soviet invasion of 1968 and turned it into a book. He and Shue decided to visit in 1974 partly for a vacation and partly to check some details in the book proofs. When they got there, Shue said, they found that the theater people Howey had written about had been so intimidated by the government that they pleaded with him not to publish the book for fear they would suffer further repressions. What began as a vacation ended as a tormenting time, with Howey finally deciding not to publish his book.

Shue became a playwright by "accident, coercion and browbeating," he says, making his initial attempt while a student at Illinois Wesleyan University, a children's play he later produced again at the Harlequin. After he left the Washington area to become a member of the Milwaukee Repertory Theatre in 1977, he was asked to write something for a workshop sponsored by the theater. A year later it was produced, and there was no turning back.

"Writing isn't very much fun for me," he says. "I like having written."

He is currently doing a film script of "The Foreigner," which is about a British man who goes to a fishing lodge in Georgia and pretends that he can't speak English, becoming a glamorous exotic as a result.

He also has a small part in Alan Alda's next film, "Sweet Liberty," Shue's movie debut. His two lines will take four days to film. He also has a part on "One Life to Live," and will appear in "The Mystery of Edwin Drood" in Central Park this summer. He's even thinking about moving to New York. It's a long way from roast beef.

The Folger Theater has set its next season, opening with "Othello." Company member Mikel Lambert will direct. "The Merry Wives of Windsor" is the holiday feature, and Chekhov's classic "The Cherry Orchard" follows. Moliere's "The Miser" and Shakespeare's "Twelfth Night" round out the year.

A polo game to benefit the theater will be held this Sunday at the Potomac Polo Club in Poolesville, Md. Admission is $4, or $15 with a reception before the match. Call 547-3230.

Dennis J. Reardon and David Kranes are splitting the National Play Award, a $12,500 grant given after a national competition. Reardon's play is "Steeple Jack" and Kranes' is "Salmon Run" . . . Nine students from colleges around the country are gathering in the Washington area this week for a two-week career development program sponsored by the Kennedy Center. They were chosen from among 250 applicants at the American College Theater festival . . . The Georgetown Workshop Theater has given a $500 grant to Teresa Jarzynski of Bethesda, who will be entering New York University next fall. She is graduating from the Duke Ellington School of the Arts.

Jerry Whiddon has been appointed artistic director of the Round House Theatre, which has been somewhat rudderless for a while. Whiddon has directed and acted there and performed at other theaters here and in New York.