Organizers today announced plans for the New York International Festival of the Arts, a month-long summer 1988 affair they hope will be the beginning of a biennial celebration here.

Festival founder and chairman Martin E. Segal, who will retire as chairman of Lincoln Center for the Performing Arts in June, said the festival's goal is to bring together internationally acclaimed artists as well as talented newcomers to perform in the city's concert halls, theaters and public parks.

The festival will be privately financed, Segal said, with a budget of $10 million to $12 million, an estimated 50 percent of which will come from box office receipts. Specific events and artists have not been determined yet.

American Express is underwriting planning and development costs with a three-year, $2.6 million grant.

"This program is not intended just for the New York community," said American Express President Louis V. Gerstner Jr., who joined Segal at a press conference here. He said the company will become actively involved in the festival by encouraging travel agents to put together special tour packages for it.

"The festival symbolizes New York City's emergence as a gateway for the best and the brightest performers from here and abroad," Segal said, describing its long-term goals. "This is not a one-time occurrence."

The festival, which will include at least two dozen concerts, ballets, operas and plays, is scheduled to open June 13, 1988, at sites throughout the city, including Lincoln Center, Carnegie Hall, the Brooklyn Academy of Music, the 92nd Street Y, the City Center and several Broadway theaters.

Its theme: the performing arts in the 20th century. "We plan to include works created in, conceived and presented in the 20th century," Segal said, adding that new works will be especially commissioned for the festival.

*Segal said an advisory commission being formed to select the festival's performers includes Mstislav Rostropovich, Leonard Bernstein, Aaron Copland, Merce Cunningham, Benny Goodman, Martha Graham, Joseph Papp, Zubin Mehta, Peter Sellars, Beverly Sills and Stephen Sondheim.