For the first time in a generation, women's wages have increased sharply relative to those earned by men, significantly narrowing the earnings gap between the sexes during the last seven years, the Census Bureau reported yesterday.

The bureau said that in the first significant change in pay ratios in decades, the average wage for full-time women workers jumped from 62 percent of what men earned in 1979 to 70 percent in 1986.

"The figures show that women have made tremendous progress in the 1980s," said Gordon Green, assistant chief of the bureau's population division.

Several leaders of feminist organizations said that however heartening the progress is, women remain far less well paid than men.

John M. McNeill, chief of the bureau's poverty and wealth statistics branch and one of the authors of the study, said the average wage for full-time women workers had been stuck at about three-fifths the average for men for three decades or more. "In 1960, it was 61 percent, and in 1979 it was 62 percent," said McNeill.

The rise to 70 percent is "an indication of upward movement," said McNeill.

Green and McNeill said the major reason for the gain in wages is that women are increasingly finding jobs in higher-paid occupations, such as law, computers and engineering, that once were considered male domains. In the past, they said, women had been clustered largely in "traditional," low-paid jobs such as teaching, nursing and clerical positions that were mainly filled by women.

For example, the study found that among full-time workers, the proportion of accountants and auditors who were female rose from 34 percent in 1979 to 45 percent in 1986; the proportion of computer programmers who were women rose from 28 percent to 40 percent; computer systems analysts from 20 percent to 30 percent; lawyers from 10 percent to 15 percent, and electrical and electronic engineers from about 4 percent to about 9 percent.

The study's findings correspond to separate Labor Department studies on the same subject.

Molly Yard, president of the National Organization for Women, said the 70 percent wage ratio figure is "nice but why isn't it 100 percent? When it gets to be 100 percent we'll cheer."

She said, "Title IX of the 1972 education amendments opened up the professional and technical schools" to women and thus was directly responsible for new opportunities in better jobs. Yard said she fears this progress may cease if a Supreme Court decision narrowing the scope of that law is not reversed by Congress.

June Inuzuka, an attorney for the Women's Equity Action League, a nonprofit group focusing on women's economic issues, hailed the improvement and said, "A lot of the developments we're seeing now are the results of the 1964 Civil Rights Act, particularly Title VII, on discrimination in employment, and of lawsuits that have opened up doors for women since the 1960s."

But she said, "They're still not equal. A persistent gap still exists, and a significant part of it cannot be accounted for by known variables. It's the conclusion of many that it's due to sex discrimination in pay, hiring and promotion policies."

The study found that although women more frequently than men take time out of their careers for family responsibilities -- and therefore accumulate less seniority and promotions than men -- that is not as important a factor on relative earnings as once thought.

Many analysts have speculated that the bulk of the wage gap is the result of a woman's movements in and out of the labor force, but the Census Bureau study found that they account for about a fifth of the wage gap among high-school and college graduates and a seventh among non-high-school graduates.

Yard said that this shows that "women are in low-paying jobs and it has nothing to do with taking time off."

The study found that about three-fifths of the remaining gap between average men's and women's wages is the result of factors such as education, work experience and seniority, the presence of a union, the size of the company worked for, the pay structure of the occupation, and the geographic area.

But the remaining one-third to two-fifths of the difference was unexplained. Women's groups often contend that at least some of that difference is because of sex discrimination.

Green said the study shows that "it helps women to get ahead in work to go to college and study 'traditional' men's preferences such as business, economics, science, law, medicine and engineering, then build up as much seniority as they can in their jobs.

"If they don't go to college they can make more money by seeking to train for and enter skilled trades that pay well."