Bernard Gersten, a canny executive who helped turn two of New York’s nonprofit theater companies into powerhouse producers and presenters of award-winning plays and musicals, died on Monday at his home in Manhattan. He was 97. The cause was pancreatic cancer, his daughter Jenny Gersten said.

Mr. Gersten was Joseph Papp’s top deputy at the New York Shakespeare Festival for 18 years in the 1960s and ’70s, a time when the two worked together to build the Delacorte Theater in Central Park for free summer productions of Shakespeare, and to turn the old Astor Library on Lafayette Street in the East Village into the Public Theater, the original home of such notable plays as David Rabe’s Vietnam drama “Sticks and Bones” and Jason Miller’s Pulitzer Prize-winner, “That Championship Season,” as well as the landmark musicals “Hair” and “A Chorus Line.”

The two men championed the work of Mr. Rabe, Vaclav Havel, Ntozake Shange, John Guare and other playwrights and helped propel the careers of actors like James Earl Jones, Meryl Streep, Martin Sheen and Raul Julia.