In his 3 1/2 years as FBI director, William S. Sessions has picked his way through a minefield of racial resentments in hopes of erasing his agency's legacy of discrimination.

Over the objections of many white FBI officials, he decided not to appeal a federal judge's ruling that the bureau discriminated against Hispanic agents. He settled another suit brought by a black agent who suffered racial threats. This spring, he began investigating whether black agents are routinely denied promotions.

But in the past two weeks, Sessions has come face to face with what may be the most trying aspect of his whole ordeal: the need to reconcile his efforts to hire and promote more minorities with the Bush administration's policies.

Emboldened by President Bush's campaign against "unfair job preferences," some white agents are challenging what they see as special treatment of minority and female job applicants. While Bush threatens to veto the Democrats' civil rights bill on the basis that it would lead to quotas, the agents claim the FBI is applying quotas itself -- reserving one-quarter of the spots in each new class of agents for minorities and another quarter for women.

While Bush insists legislation must leave employers free to hire the most qualified applicant, these agents claim the FBI lowers the minimum test and interview scores for minority and female applicants in order to fill its goals or quotas.

At two FBI field offices last week, agents gathered to discuss the growing controversy. Roughly 200 agents cast ballots on resolutions against racial and sexual quotas and goals in hiring or promotion at a lunch-hour meeting of the Washington chapter of the agents' professional association. The results are not yet available. Agents in Miami held a similar meeting.

On Friday, the FBI announced it is reviewing its hiring policies, with the help of the Justice Department's civil rights division. Deputy Attorney General William P. Barr said the department wants "to ensure that the bureau's hiring policy is consistent with both the law and the department's policy."

At the same time, the bureau took steps to remove the issue from the public spotlight. Requests for information about hiring and promotion policies were turned down. FBI officials first prepared, then scrapped, a 1 1/2-page statement saying Sessions is concerned about "an unacceptable lack of diversity among agents" but is committed to hire "only exceptionally qualified" applicants.

For Sessions, a quiet-mannered former federal judge, the growing outcry from white agents infinitely complicates the racial conundrum before him. The white agents are complaining about the hiring system mainly because they fear he will build racial preferences into the promotion system, making it harder for them to advance.

But if he doesn't alter promotion policies, Sessions risks a class-action suit from the black agents and another legal determination that the bureau systematically discriminates against racial minorities. "These are very ticklish situations," said one administration official. "Bill, to his credit, is trying to solve the problems, but it's not a good situation."

The White House is of little help because while Bush has seized every opportunity to decry quotas and unfair preferences, he has never spelled out what he considers acceptable measures to increase hiring and promotion of minorities.

Both black and white agents claim promotions depend too much on subjective assessments and personal loyalties of superiors, who "hook" their favorites up the career ladder. "The hook is alive and well in the FBI," one white agent said.

A highly critical study conducted for the bureau earlier this year by Psychological Services Inc. said the criteria for winning a promotion vary greatly, depending on who is making the decision, what the job is and who applies.

"The single most important selection criterion is the candidate's reputation . . . which is based on unstandardized and informal evaluations and which is undocumented," the study found.

The bureau's black agents contend the old-boy network hurts them more, because there is only a handful of minorities in supervisory or management positions. Only one of the FBI's more than 55 field offices is headed by a black agent. Another is headed by a Hispanic agent who won a discrimination suit.

"If we were all treated fairly and objectively, we wouldn't have to do all this," said one senior FBI official who believes black agents' complaints are justified. "But white people don't see a problem."

In an initial list given to Sessions, a group of the bureau's 468 black agents cited 19 concerns about promotions and assignments. Among them: Jobs are filled before the openings are announced; job descriptions are tailored for a specific individual; black agents receive disproportionately lower performance reviews and assessments of their potential for management; black agents are routinely left out of "blue chip" or high-profile investigations, and black agents are routed to urban areas.

David Shaffer, an attorney from Arnold & Porter who represents the black agents on a pro-bono basis, and Joe Sellers, of the Washington Lawyers Committee for Civil Rights Under Law, are analyzing bureau records for statistical support for the black agents' allegations.

While they don't know what remedies they might seek, Shaffer said, "These black agents don't want any special favors. They want to make their own way just like everyone else."

But some white agents fear special favors are exactly what Sessions has in mind. "Previously it was only hiring, and people didn't care because it was going on below them," said one white agent. "But under Sessions it's going to involve promotions. . . . Now it's time to make things even, so they're going to take my job and give it to the son of someone that they discriminated against 20 years ago."

"We're just talking basic fairness," said Larry Langberg, a foreign counterintelligence agent in Los Angeles who heads the FBI Agents Association. The nongovernmental group, which includes about 5,800 of the bureau's 9,890 agents, is expected to address the issue of hiring and promotion policies at a national meeting later this month.

"If the facts show there is discrimination, then that has to be changed. We want that straightened out. But we don't want anyone receiving special treatment based on race or gender," Langberg said.

Some agents are already calling on the bureau to revise its hiring policies, saying they fly in the face of Bush's philosophy.

According to James Perez, the bureau's equal opportunity officer, the minimum passing score on a written test is three points lower for minority and female applicants than it is for white males with no special qualifications, like a law or accounting degree.

Other agents claim female and minority applicants get a two-point boost on interviews, allowing them a total advantage of five points out of 100 over white males with no special qualifications. With about 8,000 applicants this year for 600 openings, "for every quarter-point you are talking large numbers of people," Langberg said.

Some agents also claim the bureau decides how many female and minority agents it wants to hire and adjusts the minimum scores to achieve it. "It's a quota system," said Hugo A. Rodriguez, a former agent who served as an applicant recruiter for the FBI for five years between 1978 and 1987.

"Somehow they would decide they want so many blacks, or so many Hispanics. Then they would go down the list until they got that number," said Rodriguez, who helped represent the Hispanic agents in their discrimination suit and now serves as a federal public defender.

For Sessions, the bureau's success in hiring minority and female agents has been a point of pride; although the bureau is still overwhelmingly composed of white males, 10 percent of agents are female, 4.7 percent are black and 5.3 percent are Hispanic.

In Sessions's second year as director, 21 percent of agents hired were female, and 22 percent were minorities. Last year, 19 percent of agents hired were minority and 20 percent were female, a slight drop Sessions attributed to the need to hire more accountants to investigate savings and loan fraud.

In some ways, the competing forces Sessions faces are reflected in the views of the candidates to head the Washington chapter of the agents' professional group.

In a statement to his colleagues, one candidate stressed the "extreme importance" that the FBI be free of discriminatory acts. A second, a woman, said "the FBI must hire only the best qualified, regardless of race or sex." A third issued a plea to agents "to find and hold onto the common ground."