PARIS, Sept. 16 — Girls are advancing steadily ahead of boys in educational achievement and aspiration, according to a report released today by the Organization for Economic Cooperation and Development.

"In most O.E.C.D. countries young women are now more likely than young men to obtain first degrees from university-level institutions," the group announced in its annual survey of educational policy. "Only in three countries — Japan, Switzerland and Turkey — is the proportion of young men obtaining first degrees significantly higher than that of young women."

According to the report, females now make up on average more than two-thirds of graduates in the humanities, arts, education and health studies but less than a third in mathematics and computer science and less than a quarter in engineering.

At 15, girls were better readers than boys in every one of the 43 countries that took part in a 2000 study. In about half the countries boys were ahead in mathematics. In most countries females had "a higher expectation toward their future occupations" than males, according to the survey.