Over the past two decades, New York's Ensemble Studio Theatre has fostered the creation of more than 5,000 new plays. Thirteen more are on view at E.S.T.'s annual festival of one-acts, "Marathon `98," which runs, in three series, May 6-June 14. The second series of plays will be performed through May 31.

Series B (May 20-31)
The Trio by Shel Silverstein, directed by Art Wolff. Laurence Luckinbill, Elizabeth Page and Janet Zarish star in this piece about a violinist demoted by her conductor -- who's also her lover. A classical trio will be onhand to provide musical backing for this piece by the author of The Lady and the Tiger and the book The Giving Tree.
How To Plant A Rose by Elizabeth Diggs; dir: Mark Roberts. Delphi Harrington and Bronwyn Maloney play out this tale of an old woman and her granddaughter. Other Diggs plays include Goodbye Freddy and Close Ties
Donut Holes In Orbit by Prince Gomolvilas; Dir: Charles Karchmer. Starring in this piece about a woman about to leave home are Barney Cheng, Wai Ching Ho, Jina Oh and Paul Whitehorn.
Scrapple At Two by Jennifer Mattern; Dir: Jennifer Mattern. William Wise and Molly Price play a father and his unattractive, always-a bridesmaid daughter. Other plays by Mattern include The Barracuda and Mister Fish and Just Resting.

Series C (June 3-June 14)
The Jade Mountain by David Mamet
Plan Day by Leslie Ayvazian
The Earthquake by Elinor Renfield & Joyce Carol Oates
Mary MacGregor by Keith Alan Benjamin
Prelude To A Crisis by Ari Roth

[The E.S.T. Marathon began (May 6-17) with Series A:
Mr. Charles by Paul Rudnick; dir: Christopher Ashley. In this comedy, a man (Peter Bartlett) who has been banished from New York teams with his devoted go-go-boy companion (Ross Gibby) and starts his own cable TV show, titled "Too Gay."
Dream by Billy Aronson, dir: Jamie Richards. Joanna Adler(Benita Canova) stars as "a woman whose tryst with a carton of ice cream is interrupted by a monster who refuses to explode." Peter Lewis also stars.
The Hundred Penny Box by Barbara Sundstrom, based on Sharon Bell Mathis' book), Dir: Woodie King Jr. A woman wants to throw out all her old things, but her son realizes too many memories lie within. Denise Burse stars, alongside Sarallen [sic], Kim Sullivan and Chad Tucker.
Killing Hand by David Zellnik; Dir: Chris Smith. A disfigured Serbian refugee visits his friends and relatives in Brooklyn. Starring Sylvia Kelegian, Chris Lutkin, Ted Neustadt and Grant Varjas.]

Among the noted writers contributing new works to this 21st annual event are David Mamet, Paul Rudnick, Shel Silverstein, Billy Aronson, Leslie Ayvazian, Keith Alan Benjamin, Elizabeth Diggs, Prince Gomolvilas, David Mamet, Jennifer Mattern, Joyce Carol Oates, Elinor Renfield, Ari Roth, Barbara Sundstrom and David Zellnik. Mamet's best-known works include Speed The Plow and Oleanna. Rudnick penned Jeffrey and I Hate Hamlet. Ayvazian wrote Nine Armenians; Singer/songwriter Silverstein is best known for his book, "The Giving Tree."

Horton Foote, author of A Trip To Bountiful and the Pulitzer winning The Young Man From Atlanta, has called EST, "a constant creative force in the American theatre where one is sympathetically encouraged to develop his talent and craft. Among those developing both at EST were Howard Korder, Steve Martin, Robert Schenkkan (The Kentucky Cycle) and Oyamo.

For tickets ($15 per series) and information on Marathon `98 at Ensemble Studio Theatre call (212) 247 4982. Casting is usually announced at the last minute, so expect actors and directors for Series C to be added in the weeks to come.

-- By David Lefkowitz and Robert Simonson