Robert C. Gallo, America's most prominent AIDS researcher, has entered "serious, substantial" negotiations to leave the National Cancer Institute and establish an international center for AIDS research at one of three major universities.

Gallo said that he wished to

create the "world's foremost institute of human virology," and said several leading scientists at NCI, part of the National Institutes of Health, and other institutions have expressed an interest in joining him. Gallo's influential career and his unabashed flamboyance have turned him into one of the country's most controversial and well-known scientists.

Gallo's lab has been a magnet for many of the world's most talented AIDS and cancer researchers, and his departure would be a blow to NIH. Johns Hopkins University has emerged as the most likely location for the new center, but Gallo has carried out extensive discussions with both Duke and Yale universities.

At least two major groups of investors -- one in Europe and one in the United States -- have discussed creating a foundation to fund the venture, which would spin off a biotechnology firm specializing in AIDS research in addition to backing basic research associated with human retroviruses.

In addition to Gallo and leading American researchers, sources in the federal health community said yesterday that French virologist Luc Montagnier, of the Pasteur Institute, may have a role in the proposed enterprise. Gallo will meet with Montagnier to discuss the options next week, according to NIH sources.

Until last March, the two were locked in a feud over who would get credit for discovering the HIV virus that causes AIDS. On March 31, they signed a treaty that designated shared credit, and Gallo said they now speak on the phone "every third day."

Nova Pharmaceuticals and several other companies have joined with Johns Hopkins in trying to lure Gallo. But Gallo has insisted that he join the medical faculty wherever he locates, something several Johns Hopkins officials have opposed.

"He has ruffled feathers everywhere else," said one Johns Hopkins medical professor who supports Gallo. "Why not here? There are plenty of egos in Baltimore and we all realize his would take up a lot of room."

NIH officials have tried to discourage Gallo from leaving and he was scheduled to discuss his plans at a dinner meeting last night with NIH director James B. Wyngaarden.

"Bob Gallo is the single most active and productive and creative person in AIDS research," Wyngaarden said yesterday in an interview. "I'd hate to see him go. We are not in a felicitous phase for any kind of upheaval. But in the long run what can we do?"

Wyngaarden noted that scientists with the accomplishments of Gallo -- or Samuel Broder, chief of clinical oncology at NCI and another leading AIDS researcher -- could earn far more at private institutions than in the government.

Broder has also been involved in discussions about the new center, although yesterday he said he was unaware of "any place other than NIH where I can do as much as I do here."

Gallo said he had not decided whether to leave or where to go, but his friends and colleagues say that after 22 years at NCI he is ready for a new challenge. Several companies have shown interest in Gallo but neither he nor other officials would name potential backers besides Nova.

With royalty payments, Gallo will earn more than $100,000 this year, according to Wyngaarden. But until now his annual salary has been closer to $60,000. NIH officials concede he could earn several times that amount if he left government service.

There has been frequent speculation in the past that Gallo, 50, would leave NCI . But until recently the rumors have not been taken seriously.

"I have never crossed the emotional boundary lines of {the NIH} before," Gallo said. "But now I have. It will be an emotional thing for me to leave here. It has been my home."

But since the NIH has shifted most AIDS funding from NCI to the Institute of Allergy and Infectious Diseases (NIAID), Gallo has worried more about his role in AIDS research.

"If we had one AIDS institute under {Anthony S.} Fauci," referring to the NIAID director, who is a close friend of Gallo's, "that could work for me. But its not that way here."

He said that in seeking a new base for his work, he does not fault NIH at all. But he said he wanted to spend the last part of his career at a "great university." He added that he sought the freedom to bring separate groups from industry, academia and government together under one roof.

A statement released by Johns Hopkins yesterday said: "We are still actively discussing future possibilities with Dr. Gallo. Nothing has been offered or accepted."

Government sources said that the departure of Gallo, Broder and several other key NCI officials would have severe implications for the federal AIDS research effort. But it was not clear whether Broder, one of the country's leading cancer and AIDS treatment experts, would leave his post.

"There are significant financial problems associated with working in the government," he said. "I have asked my family to make sacrifices to further my career. While earning $63,000 is not taking a vow of poverty, I don't think there is anything wrong with wanting better things for my wife and family.

"But NIH is unique," Broder added. "It provides the only opportunity for rapid effective drug development on a wide scale. And we need that badly."