Mayor Marion Barry acknowledged yesterday that even after lowering the passing score on a police verbal skills examination and ranking those who passed on the basis of a lottery rather than test scores, the results still do not adhere strictly to federal antidiscrimination guidelines.

The mayor's action thus lessens the disparity between the proportion of blacks and whites who passed the March 28 test, but leaves the city susceptible to a potential court challenge from minorities under Title VII of the Civil Rights Act of 1964, according to city government and federal lawyers.

"We still didn't make it, but we're close," Barry said yesterday, as city officials began drawing names in the lottery.

Deputy Corporation Counsel Charles Reischel, a former lawyer with the U.S. Equal Employment Opportunity Commission, said, "We may still have a problem . . . . We would have to argue that we adjusted the scores as best we could under the circumstances."

Reischel said that if the city's procedures are challenged in court, city lawyers would likely argue that the revised results are a dramatic improvement over test results before the passing score was lowered, and that the city made every effort to comply.

An EEOC spokesman said yesterday that the guideline in question is not an absolute determinant of discrimination, but rather one of several factors a judge might consider in concluding whether discrimination had occurred. Still, the spokesman said, full compliance generally is better than partial.

Barry said last week that results of the test appeared to discriminate against women and minorities. He ordered that the passing score on the 80-question test, which has been given to D.C. police candidates since 1948, be lowered from 40 to 35 in order to include more blacks and women in the pool.

And, over the objections of the leaders of the predominantly white union that represents the police officers, the mayor also mandated the lottery, which means that those who scored highest on the exam have no more chance of being called first than anyone else. Although more than 75 percent of those who took the test were black, 62 of the top 100 scores were registered by whites.

The complicated guidelines state that the percentage of minority applicants who pass a qualifying test should be at least 80 percent as great as the percentage of whites who pass the test.

After the adjustments, officials said, about 70 percent of blacks who took the test passed it, while 95 percent of whites who took the exam were successful -- leaving a ratio of about 74 percent.

Before lowering the passing score from 40 to 35, officials were left with results that showed 94 percent of whites passing the test and only 54 percent of blacks. That much of a disparity, Reischel said, would have been a strong indicator of discrimination.

In essence, Richard T. Seymour of the Lawyers Committee for Civil Rights Under Law explained yesterday, the 80 percent guideline was intended as a kind of "rough rule of thumb" to alert government prosecutors to cases of apparent discrimination. He added, however, that a judge likely would look for compliance with the rule before deciding to proceed to other issues, such as whether an examination is actually related to job performance.

Seymour said the guideline also might be cited in a lawsuit by private individuals charging discrimination. The vast majority of lawsuits under Title VII are brought by individuals, he said.

Police Chief Maurice T. Turner chose the first candidate at the drawing ceremony in the City Council chambers yesterday, sticking his hand into a spherical plastic hopper thar contained the names of applicants deemed to have passed the March 28 qualifying exam from which about 200 new police officers are expected to be chosen. Employes of the D.C. Personnel Department completed the drawing of the other 634 names.

The lottery was to determine the order in which those who passed the test with 35 or more correct answers will be called for physical exams, background checks and admission to the police academy.

All likely will be called, Turner said, but it may be months before applicants at the bottom of the list hear from the city.

New York City, under pressure from minorities, recently held a similar police lottery.

The racial composition of the city's work force -- especially the police and fire departments -- has long been a sticky political issue in Washington, whose population is 70 percent black. Currently, 45 percent of the 3,620-member police force is black.

Barry's decision to adjust the test results has been criticized by some police officers, who said they feared the lowering of the passing score would give the impression that police standards were being lowered. Others have contended that the lottery is unfair to those who scored highest on the test and thus expected to be called first.