Challenging widespread assumptions, a study of 13,000 workers has concluded that young women in blue-collar, male-dominated occupations do not quit their jobs with more frequency than their male counterparts.

The Rand Corp. analysis of U.S. Labor Department data appears to be the first study of its size and scope to contradict the view that it is better to invest money hiring and training young men because they won't quit to marry or bear children.

Of full-time 1979 employes in the study, 57 percent of men versus 55 percent of women had left their jobs within a year. The study also showed that the turnover among young women in nontraditional jobs, such as welding and truck driving, was no higher than for women in traditional jobs, such as secretarial work.

Women's movement leaders hailed the report for giving a firm statistical base to arguments they long have been making to government policy-makers and employers. Given today's economic pressures, women are no more likely than men to quit jobs in better-paying predominantly male trades "because they really need the money," said Sally Steenland, deputy director of the National Commission on Working Women.

Judy Goldsmith, president of the National Organization for Women (NOW), called the study "wonderful."

"One of the things it does is show that job turnover is not a significant contributor to the wage gap," Goldsmith said. In arguing for new laws to equalize pay for men and women with similar skills and backgrounds, NOW has said that women's average wages are less than men's because of discrimination, not the frequency of job changes.

The analysis of the large random sample of men and women aged 14 to 21 in 1979 was funded by the Ford Foundation and written by Rand sociologists Linda J. Waite of the research group's Santa Monica, Calif., headquarters and Sue E. Berryman of its Washington, D.C., office. Because of the relatively young age of those sampled, the study deals mainly with occupations that do not require a college degree.

Waite, in an interview, said she was particularly intrigued by the potential impact of military service on women identified in the study. Women are gaining technical training in the military on the same basis as men, and may, like minority groups before them, move back into civilian life to challenge male dominance in several career areas.

The study showed that 34 percent of women in the military are assigned to the most male-dominated jobs -- those where fewer than 10 percent of workers have traditionally been women -- while 3 percent of civilian female workers now hold such jobs.

The military limits on female participation in some technically skilled, combat-related jobs thus become very important, Waite said. "The country's verbal and legal war over whether women should be trained and used in combat can ultimately be seen as a war over women's rights and obligations, not only in the military, but also in the larger society," she and Berryman concluded.

The study, "Women in Nontraditional Occupations: Choice and Turnover," reported that girls and women accept traditionally male jobs 19.5 percent of the time. They are far more likely to try a job not dominated by their own sex: 75.7 percent of males chose traditionally male jobs, while 47.2 percent of females chose traditionally female jobs.

Only 2.3 percent of males chose traditionally female jobs. Of the rest, 33.3 percent of girls and women and 22.1 percent of boys and men chose jobs where the work force is about evenly divided between men and women.

Some researchers had speculated that girls raised in secure two-parent households would be more likely to develop the self-confidence necessary to try male-dominated fields, but the opposite turned out to be true. The Rand study shows girls aged 14 to 17 in female-headed households are far more likely to take traditionally male jobs.

Waite said she concluded that girls who are shocked at their mothers' financial struggles are most likely to see the advantage of gaining an early hold on a better-paying job in a male field. The findings hold for white and Hispanic girls, but not blacks, perhaps because female-headed households have become more of a fixture in black society.