The number of women and minorities employed by Fairfax County has been increasing, but few of those gains have been in the higher paid or top management positions, according to a new county report.

The report said that the percentage of females and all minorities, except Hispanics, employed by the county increased during an 18-month period that ended in December. But the study found that the gains were not made in all job categories, "and in many categories the distribution of women and minorities remains less than the theoretical ideal."

The number and percentage of women and minorities in the county's top management actually decreased and remained below the county's target, the report said. Women "continue to be concentrated in traditionally female occupations and both women and minorities are over represented in the lower ranges of the pay scale," it said.

The job categories containing the largest number of females and minorities are office and clerical jobs, which are 91.7 percent female; service and maintenance, which are 35 percent minority; and para-professionals, like paralegals and library aides, 66 percent female.

The study found that 46.4 percent of the males made over $25,000, while only 14.5 percent of the female employes made that much. Nineteen percent of the minority employes had salaries over $25,000, compared to 36.9 percent of the white employes.

The Justice Department sued Fairfax in 1979 over alleged sex and race discrimination. That case was settled in April 1982, with Fairfax admitting no wrongdoing but agreeing to pay a total of $2.75 million to 685 alleged victims and to hire 150 of them. By the end of 1982, 60 of them had been appointed. The county said that because many of the others have withdrawn, it believes the county will have to hire no more than 31 additional people.