The Justice Department said yesterday it will segregate federal prisoners who test positive for the AIDS virus and display "predatory or promiscuous behavior."

The new policy, which will begin immediately, also calls for testing all prisoners who are within 60 days of their release, exhibit any clinical manifestations of acquired immune deficiency syndrome or who request tests. It also requires tests for those who will be involved in community activities, such as work-release programs.

In addition, the department released statistics showing that 3 percent of 16,000 federal prisoners tested in a pilot program have tested positive for the AIDS virus. "Considering the prevalence of intravenous drug use, the statistics are not that high," said Urvashi Vaid, a spokeswoman for the National Gay and Lesbian Task Force. "People who are raping other prisoners should be separated."

She voiced concern, however, about confidentiality of test results.

"We are concerned that the prison officials will use that information to deny inmates access to community programs such as halfway houses and family visits," she said.

Bureau of Prisons spokeswoman Kathryn Morse said fewer that one percent of the existing prison population would require separate cells as a result of positive tests. She added that only medical staff and the prison warden would know results of tests.

"But if we feel that he's going to put other inmates at risk, then we would separate him," Morse said.

Department officials said they will rely heavily on education and training programs to battle AIDS in federal prisons. They said there are 31 cases of AIDS in the federal system, out of a population of 44,000.

Inmates who have tested positive for the virus but have shown no symptoms of the disease remain within the general prison population.

Staff writer Ruth Marcus contributed to this report.