Curt Dempster, 71; was a founder of Ensemble Studio Theater in N.Y.

Curt Dempster, who co-founded Ensemble Studio Theater, a company known for its commitment to one-act plays and new pieces, has died. He was 71.

A director, playwright and actor, Dempster died Friday at his home in New York, said theater spokesman David Gersten. The cause of death has not been determined.

Dempster was the founding artistic director of the Manhattan venue, which is dedicated to developing new plays and nurturing theatrical talent. Established in 1971, the theater has staged works by Joyce Carol Oates, Arthur Miller and David Mamet, among others.

The theater became partiularly recognized for its yearly festival of one-act plays -- a format many playwrights like but that Broadway tends to be lukewarm about. Over the last several years, the theater staged more than 250 new works each season.

“We wanted to focus attention on the neglect the one-act had fallen into,” Dempster said in 1990. “We wanted to restore it to its place in literature.”

The theater’s small but selective membership included writers Mamet and John Patrick Shanley, and actors Ellen Barkin, William H. Macy and Richard Dreyfuss, the New York Times reported in its obituary of Dempster.

Plays developed at the theater include “Sister Mary Ignatius Explains It All for You” by Christopher Durang.

Frank Curtin Dempster was born Nov. 1, 1935, in Detroit. Besides staging plays, he also wrote several, including “Mimosa Pudica,” which was included in the compilation “The Best Short Plays 1977.”

As an actor, he appeared off-Broadway in Miller’s “A View From the Bridge” and in the films “Desperately Seeking Susan” and “The Manhattan Project,” according to Gersten and online theater and film databases.

In recent years, Dempster taught acting, directing and playwriting at the Ensemble Studio Theatre and elsewhere, Gersten said.

He left no immediate survivors.