Backers of California's ban on racial preferences have sued the Berkeley Unified School District, saying it is violating the law by trying to create racial balance at its elementary schools.

In a suit filed late Wednesday in Alameda County Superior Court, the Pacific Legal Foundation said the district's program -- which seeks an enrollment at each school within 5 percent of the district's overall racial population -- violates Proposition 209.

The initiative, passed in 1996, prohibits racial preferences in public employment, contracting and education.

The Pacific Legal Foundation said an appellate court ruling last year, which used Prop. 209 to strike down a Huntington Beach district's voluntary desegregation program, also doomed the Berkeley program. Under the Berkeley program, parents must specify their children's race when they state their preference for elementary schools. The students are then assigned by a computer program that takes race into account.

"Classifying people by race results in racial discrimination and has no place in American life," foundation attorney Cynthia Cook said Thursday. The foundation represents a Berkeley man with two children in school.

Berkeley has had some type of voluntary desegregation system since the late 1960s -- the first of any school district in the nation -- but is studying changes to its current system because of Prop. 209 and the Huntington Beach case, said Superintendent Michele Lawrence. The district has 3,500 to 4,000 students in elementary schools, through fifth grade, out of a total enrollment of nearly 10,000, she said.

"We think we'll still be able to create diversity in our schools but will have to use different criteria," Lawrence said. She said the district believed it could continue to consider race as "one of many factors" and planned to resume a school board review next month of proposals offered by a task force of parents, school staff and community members.