Updated

A group of coaches, parents and others is suing the Education Department over how it determines whether high schools are complying with the federal law that bans sex discrimination in schools that receive federal money.

At issue is a three-part test to judge a school's compliance with the 1972 law, known as Title IX: having male and female athletes in proportion to their enrollment; showing a pattern of expanding opportunities for females; or proving the sports interests of females have been met.

The American Sports Council argues in the lawsuit, being filed Thursday by the Pacific Legal Foundation, that the test, as applied to high schools, violates the equal protection clause. The group claims it will lead to quotas and the elimination of boys' sports teams, and is seeking a court order to stop the department from using it.

Education Department spokesman Jim Bradshaw called the test a "valuable tool" for ensuring a level playing field for all students. "It plays a critical role in ensuring a fundamental level of fairness in America's schools and universities," he said.

Title IX has helped open more academic and sports opportunities for women and girls.

The council, formerly the College Sports Council, was one of several groups that also challenged the three-part test for college sports. A federal judge dismissed the case in 2003, saying the plaintiffs didn't have the right to sue.

Before the law, less than 300,000 girls participated in high school sports, compared with 3.5 million boys, according to the department. In 2007-08, the number of girls participating increased to 3 million, compared with 4.4 million boys.

The council's chairman, Eric Pearson, said his group was concerned about complaints filed with the department last fall by the National Women's Law Center, which claimed that 12 school districts violated Title IX by not offering equal opportunities for girls.

The center cited double-digit gaps between the percentage of female students and the percentage of female athletes. The center said many sports weren't offered to girls in the districts, and that the gaps had gotten worse in recent years.

Pearson said his group's suit was intended to stop the department from acting on those and other recent complaints. He said a proportionality test would lead schools to cut boys' teams. He noted that 1.3 million more boys than girls play high school sports, according to a National Federation of State High School Associations 2009-10 survey.

"We are trying to prevent boys from being punished," he said.

Neena Chaudhry, senior counsel at the center, said that the three-part test is flexible and that there's no evidence that boys have been hurt by it.

"From our perspective, this is not a zero-sum game -- we want opportunities for boys and girls," she said. "Unfortunately, schools are still not devoting the resources and the same opportunities for girls as they are for boys."

In 2007, the council filed a petition with the department, seeking a determination that the three-part test does not apply to high school athletics. The following year, the department denied the petition.