The case before the court concerned arbitrary employment decisions that do not involve race, gender or other categories that are explicitly protected by federal law.

Individual public employees typically have a variety of protections from personnel actions, but invoking the equal protection clause of the Constitution is not one of them, Chief Justice John Roberts said in his majority opinion.

The court's 6-3 decision in the case from Oregon was one of four opinions handed down Monday as the justices race to complete their work before their customary summer break begins in late June. Twenty-two cases remain to be decided and more opinions are expected Thursday.

Major cases still undecided include the rights of detainees at Guantanamo Bay, the ban on handguns in Washington, D.C., and whether people convicted of raping children can be given the death penalty.