"Joe and I played bad cop, good cop. He's tough. I'm gentle. He's a street fighter and I'm a pacifier."

Thus producer Bernard Gersten characterizes the 19-year association with Joseph Papp that built the New York Shakespeare Festival from a $170,000 obscure enterprise to a $35-million-a-year colossus of the theater world.

It was they who gave us Shakespeare in Central Park, both classics and contemporary drama at Lincoln Center's Vivian Beaumont, numerous television specials and - most important of all - nonprofit drama at the downtown Public Theaters. That is the birthplace of "That Championship Season." "For Colored Girls Who Have Considered Suicide When the Rainbow Is Enuf" and, of course, "A Chorus Line."

But the team that made the Shakespeare Festival has split. And the implications for the future of their institution are one of the most frequent topics of theater gossip. Can Papp run the festival alone? Can the two be reconciled? Will Gersten come back?

Ironically, the festival's most spectacular success led to the break. Michael Bennett's "A Chorus Line" had Papp as its producer and Gersten as associate producer. It went from the Public Theaters to Broadway and into, subsequent productions that have made it at present the most lucrative musical ever.

So when Bennett started work on his new musical, "Ballroom," it was natural that he should seek out Papp and Gersten to produce it.

"Joe was bothered that it could not open on a non-profit basis in the Public Theaters. He thought this violated what the Shakespeare Festival stood for. But there simply was not enought space on our stages," said Gersten during a busy evening last week.

"He also didn't like the idea of putting on a show that someone else had already packaged - in other words, just putting up the money.

"I disagreed. It seemed to me that Joe and I had a Talmudic obligation to he discharged to Michael. After all, Michael had been a lifesaver for the festival with 'A Chorus Line.' We needed help then and he gave it. Now he was asking for help.

"Joe changed his mind three times over a period of several weeks. And the second time around Michael asked, 'Can I have the services of Bernie?' Joe said 'no,' and I was appalled. I only wanted four months, because 'Ballroom' opens here on Dec. 1. And I told Joe I would continue my work for the festival at the same time. But he wouldn't yield. So on Aug. 28 I became co-producer (with Bennett) of 'Ballroom.'"

"Leaving the festival really hurt. Joe is brilliant. But I belive one of my roles over the years was to curb his unreasonable behavior. And I'm sorry I couldn't do that in my own case, because I think he made a mistake to let me go."

Charles Christopher Mark, who once had a play produced by the festival, describes the partnership in his Arts Reporting Service newsletter: "One (is) a driving genius in pursuit of theatrical dreams. The other a calm and humane adviser on practical matters. It was a rare and winning combination seldom found in any enterprises."

Gersten recalls an example. "We were at a meeting of the city Board of Estimates seeking a grant that was absolutely essential if we were going to stay in business. Joe was testifying and a brash new member asked in a rather accusatory tone, 'Mr. Papp! Just what is this money going to do for the Bronx?" Joe blew up and declared, 'Mister, I've been doing things for the Bronx long before you came along.' After a heated argument, Joe stood up, declared, 'I'm not going to take any more of this s -' and stomped out. I had to step in and calm the ruffled feathers. I made our case, answered all the questions and the grant finally came through."

Gersten disagrees with Papp's concern at keeping nonprofit theater and commerical theater separate.

"The distinction is increasingly unimportant. I'd like to abolish the phrase 'commercial theater.' These days we find works of much substance moving from one sector to another. Was 'A Chorus Line' any different when it was at the Public Theaters than when we took it to Broadway? (The show returns to Washington for 14 weeks at the National starting Nov. 27. according to Gersten.) Meanwhile, "Ballroom" moved to the American Shakespeare Theater in Stratford, Conn., last week. Its previous begin there Oct. 24.

Based on the television drama. "The Queen of the Stardust Ballroom," it is (like "A Chorus Line") full of dance. The story concerns a 56-year-old woman recently widowed after 38 years of marriage who feels that her life has ended with her marriage. She finds new life at a dancing hall, where she is eventually crowded queen by her newly found friends.

After "Ballroom," Gersten has no existing plans. And both he and Papp seem to be leaving open the possibility of a return to the Shakespeare Festival.

"Sure we're both mad at each other. But I think the mood was of considerable regret on both sides," says Gersten. Asked if he could conceive of returning, he says, "Yes. Of course."

The outspoken Papp is uncharacteristically restrained on the topic, however."I really just don't want to discuss this matter until some future time," he said Tuesday. "I'm not trying to rationalize what happened. It's just taken its course."

And even though they are no longer working together, Gersten could not resist taking in Papp's recent debut as a cabaret singer at The Ballroom, "a tiny nightclub in Soho. "I just could not not see Joe perform," he said.

Gersten was asked if he liked the show. "Yes."

Then he was asked if he went backstage to congratulate the performer. "No. I'm afraid."

The two have not been in contact since the breach.