Since current rules began in 1975, single-sex classes have been allowed only in limited cases, such as sex education courses or gym classes involving contact sports.

Under the new rules, schools could separate genders for a variety of subjects if they believed it offered educational benefits, such as promoting greater student comfort or higher attendance. In all cases, enrollment in a single-sex class would be voluntary.

If a school creates a single-sex class, it would not be required to offer the other gender its own similar class, but it would have to offer a coed version of it.

The rules also make it easier to create single-sex schools, as long as the district can demonstrate that it also provides coed schools with “substantially equal� benefits to the excluded sex.

The changes affect elementary and secondary education, but not colleges. The current ban on single-sex vocational education in both classes and schools at the K-12 level will remain in effect.

The new regulations also require that school districts evaluated their single-sex classes at least every two years to ensure compliance with the Title IX law.

“The department’s office for civil rights is responsible for investigating any complaints in discrimination. We take that charge very seriously and will continue to fully investigate any allegation,� said Stephanie Monroe, the department’s assistant secretary for civil rights.

Education officials said some districts were interested in single-sex schools but said they do not expect a rush to make wholesale changes. In most cases, local school leaders will probably wait until at least the next semester to ponder moves, they said.

Single-sex classrooms have become more common in recent years. In 1998, only four public schools had them, compared to at least 228 this year, according to the National Association for Single Sex Public Education.

— Associated Press