A federal judge has ordered the Chicago Public Schools into court next month in a move that may lead to the scrapping of the district's school desegregation plan, which has been in place for more than 20 years.

U.S. District Court Judge Charles P. Kocoras, citing the district's changed ethnic makeup, said the plan was outdated. "It is either time for a new decree or time to end this one," he said.

He scheduled a Feb. 27 hearing.

At issue is the desegregation plan the district agreed to in 1980 in order to avoid a legal battle with the U.S. Justice Department.

Since the plan was adopted, the percentage of black students in the city's public schools has shrunk from 60 percent to 50 percent. Latino students now make up 35 percent of the total — nearly twice what they represented in 1980 — and white children represent 10 percent.

Kocoras' order came as a surprise to school officials, who are in the midst of a yearlong review of desegregation policies.

Some school officials expressed concern that scrapping the consent decree might endanger the district's highly regarded magnet schools, created as part of the agreement, the Chicago Tribune reported in Saturday editions. Admissions policies at the magnet schools are based in part on the goal of achieving racial diversity.

Schools chief Arne Duncan said he and other district officials were committed to maintaining the magnet schools, as well as other features of the 1980 plan.