Bernard Gersten, whose retirement as executive producer of Lincoln Center Theater was announced on Monday, said on Tuesday that he would write a memoir of his 67 years in theater. Mr. Gersten, who turned 89 in January, is one of the last titans of the 1970s and '80s, when nonprofit theaters emerged as artistic and financial rivals to commercial Broadway. Acclaimed hits like ''A Chorus Line'' opened at the Public Theater in 1975 and then ran on Broadway for 15 years. Mr. Gersten helped create Lincoln Center Theater in 1985 after a revolving door of companies had struggled for two decades to mount shows at the Vivian Beaumont Theater on the Lincoln Center campus. Before moving uptown Mr. Gersten helped to run the Public in the East Village from 1954 until 1978. ''I stayed as long as Lincoln Center Theater would have me, and I would have stayed longer, but the timing is appropriate,'' Mr. Gersten said. He is among the highest paid executives in American nonprofit theater; in 2010, according to the latest available tax records, he was paid $506,417, and he will receive a payout of $450,000 in deferred compensation upon leaving. Lincoln Center Theater will not appoint a successor to Mr. Gersten; his duties will be shared among executives including Andre Bishop, the artistic director, and Adam Siegel, the managing director. [ABSTRACT FROM AUTHOR]