NEW YORK (AP) _ An art dealer imprisoned for tax evasion was cleared of charges that he humiliated and tortured a teacher for six hours during a sado-masochistic homosexual encounter.

The state jury acquitted Andrew Crispo of kidnapping, sodomy, assault and coercion because members believed the teacher had agreed to the ordeal, said juror Ara Derderian.

The jury, which reached its verdict on the sixth day of deliberations Sunday, deadlocked on a charge of unlawful imprisonment. The district attorney's office was considering dropping the charge.

Crispo, 43, had denied the charges by Mark Leslie, a 28-year-old college English teacher from Montreal who said Crispo and four young men imprisoned and brutalized him in Crispo's Manhattan gallery on Sept. 20, 1984.

Defense lawyer Robert Kasanof called the verdict ''protection for everybody's liberty.''

He noted that Leslie met Crispo admitted he liked getting hit and feeling ''a little pain'' during sex and paid the check when he went out to dinner with Crispo after the encounter.

Assistant District Attorney Joel Seidemann, who described Crispo during the trial as ''a master manipulator'' who ''deals art by day and torture by night,'' said simply, ''The jury has spoken.''

Leslie, who fled to Vancouver, British Columbia, after Montreal newspapers published his name, address and photograph, denounced the verdict in a statement.

''My purpose in bringing this charge was to prevent Andrew Crispo from beating, torturing or killing other young men,'' the statement said. ''Justice (Jeffrey) Atlas' rulings throughout the trial and the subtle bias of his charge to the jury make a profoundly disturbing statement. In our society it is acceptable to brutalize and even murder gay men.''

Leslie testified at the trial but was not present for Atlas' instructions to the jury.

He had testified that he had two sadomasochistic encounters with Crispo and snorted cocaine with him. At the second encounter, Leslie said, he was attacked at the gallery against his wishes and left bleeding, crying and handcuffed. He said he expected some rough sex but did not consent to being tortured.

''Leslie did not protect himself by saying there's a limit to what I'm willing to do,'' said Derderian, a 60-year-old architect who was the only juror to talk to reporters after the verdict. ''There was a mistaken idea of what each side meant by domination.''

A key prosecution witness was Bernard LeGeros, 26, who pleaded guilty to attempted kidnapping in exchange for his testimony against Crispo.

LeGeros is serving 25 years to life for the sadomasochistic murder in February 1985 of Eigil Dag Vesti, 26, a Norwegian fashion student and model. Crispo was implicated but never charged in Vesti's death.

Vesti's body was found on the estate of LeGeros' parents. After seeing news naming LeGeros and Crispo, Leslie went to the police.

Crispo has served 2 1/2 years of a five-year federal prison sentence for tax evasion and is eligible for parole, according to his attorney Mary Shannon.