Women in science and engineering are hindered not by lack of ability but by bias and "outmoded institutional structures" in academia, an expert panel reported on Monday.

The panel, convened by the National Academy of Sciences, said that in an era of global competition the nation could not afford "such underuse of precious human capital." Among other steps, the report recommends altering procedures for hiring and evaluation, changing typical timetables for tenure and promotion, and providing more support for working parents.

"Unless a deeper talent pool is tapped, it will be difficult for our country to maintain our competitiveness in science and engineering," the panel's chairman, Donna E. Shalala, said at a news conference at which the report was made public. The report, "Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering," is online at www.nationalacademies.org.

Shalala, a former secretary of health and human services who is now president of the University of Miami, said part of the problem was insufficient effort on the part of college and university administrators. "Many of us spend more energy enforcing the law on our sports teams than we have in our academic halls," she said.

The panel dismissed the idea, notably advanced last year by Lawrence H. Summers, then the president of Harvard, that the relative dearth of women in the upper ranks of science might be the result of "innate" intellectual deficiencies, particularly in mathematics.

If there are cognitive differences, the report says, they are small and irrelevant. In any event, the much-studied gender gap in math performance has all but disappeared as more girls enroll in demanding classes. Even among very high achievers, the gap is narrowing, the panelists said.

Nor is the problem a lack of women in the academic pipeline, the report says. Though women leave science and engineering more often than men "at every educational transition" from high school through college professorships, the number of women studying science and engineering has sharply increased at all levels.

For 30 years, the report says, women have earned at least 30 percent of the nation's doctorates in social and behavioral sciences, and at least 20 percent of the doctorates in life sciences. Yet they appear among full professors in those fields at less than half those levels. Women from minority groups are "virtually absent," it adds.

Along with Shalala, the panel included Elizabeth Spelke, a professor of psychology at Harvard who has long challenged the "innate differences" view, and Ruth J. Simmons, the president of Brown University, who established a widely praised program for aspiring engineers when she was president of the all-female Smith College.