The Pennsylvania Supreme Court has upheld state Education Secretary Gerald Zahorchak's decision to appoint a new governing board in the Chester Upland School District in March, replacing the Republican-dominated board that had run the district since 2003.

The unanimous ruling was handed down yesterday; two justices filed a separate, concurring opinion.

Zahorchak declared when he appointed the new board that the 4,200-student Chester Upland district had reestablished a sound financial structure. That meant, he said, that the previous state-appointed board, assembled to address the struggling district's financial woes, could legally be replaced with one that would concentrate on academic problems.

Two members of the old Republican-appointed board - Michael F.X. Gillin and Wallace Nunn - argued that the new appointments were illegal. They claimed that Zahorchak's decision was made in bad faith because the education secretary was looking for an excuse to bring in a new leadership group.

The court ruled yesterday that Zahorchak had acted within the law in making his decision, saying, "This court will not disturb administrative discretion in interpreting legislation within an agency's own sphere of expertise, absent fraud, bad faith, abuse of discretion, or clearly arbitrary action."

Gillin said yesterday he had not seen the decision and could not comment on it.

Because of its financial and academic troubles, the district has been under some form of state control since 1994; it is among the worst-performing districts in Pennsylvania on state accountability tests. The board that Zahorchak appointed is headed by Philadelphian C. Marc Woolley, director of strategy and planning for the Delaware River Port Authority. Its other two members are Juan Baughn, a former Education Department liaison to the district; and Kathy Schultz, a faculty member at the University of Pennsylvania Graduate School of Education.