Health and Human Services Secretary Margaret M. Heckler ordered the National Institutes of Health yesterday to suspend funding for brain-trauma experiments on monkeys at a University of Pennsylvania head injury clinic, prompting more than 60 animal rights activists to claim "complete victory" and end their four-day sit-in at NIH offices in Bethesda.

Heckler ordered a halt to research at the Pennsylvania Head Injury Laboratory until the "serious concerns" raised about procedures used at the laboratory are answered.

Heckler took the action yesterday after receiving a preliminary report from NIH investigators reviewing work at the Pennsylvania clinic. The report was scheduled for completion today, but was expedited because of the sit-in at the offices of the National Institute of Neurological and Communicative Diseases and Stroke, according to NIH spokesman Storm Whaley.

In a prepared statement, Heckler said: "The use of animals must occur under protected and humane conditions, and only for scientifically necessary purposes . . . . I have been informed that serious concerns have been raised about procedures used by the University of Pennsylvania in the use of primates to study head injury . . . .

Until all questions about the use of primates in these head-injury experiments have been satisfactorily resolved, I have instructed NIH to suspend the use of federal funds for primate research on head injury at the University of Pennsylvania."

NIH Director Dr. James Wyngaarden later issued a statement saying he had complied with Heckler's order. He said the investigators' preliminary report "indicates material failure to comply with the Public Health Service policy for the care and use of laboratory animals."

Wyngaarden said he will decide whether to end the project after the university responds to the report.

University of Pennsylvania spokesman Virgil Renzulli said officials there had not yet received a copy of the report, but a statement by University President Sheldon Hackney and Provost Thomas Ehrlich said that "any fault in research will be corrected."

About 65 demonstrators who remained in the eighth-floor NIH offices ended their protest yesterday afternoon after hearing of the statements by Heckler and Wyngaarden. The sit-in began Monday morning and lasted more than 77 hours.

The demonstrators, mostly members of People for the Ethical Treatment of Animals, held hands, sang and cried as they were reunited with friends, relatives and other animal-rights activists who held signs and applauded their exit through the front doors.

"This is a complete victory," said Gary Francione, a lawyer for the group. "It couldn't have worked out any better."

But Frank Martin, president of the Pennsylvania chapter of the National Head Injury Association, which represents victims of brain damage, expressed anger at Heckler's decision, saying that families of the persons who have benefited from animal brain research were not consulted. "She did this with total disregard for what our needs are," he said.

Martin said his 20-year-old son suffered brain damage four years ago. Research in head injuries has helped him make a significant recovery.

"If it comes to a choice that's going to help my son, I'll take what's going to help him and all the kids like him," Martin said.

Dr. William Raub, director of off-campus research for the neurological institute, said he saw the report and supported the funding suspension because of the improper anesthesia and unsterile techniques allegedly used in the lab. He said, however, that scientists at the university had been able to identify and drain fluids in the brain caused by head injuries, thus lessening brain damage.