A federal lawsuit filed by a civil rights group alleges KB Toy Stores discriminated against black customers by refusing to let them pay with a personal check.

The Equal Rights Center of Washington and two other plaintiffs allege in the lawsuit filed on December 15th in U.S. District Court in Baltimore that KB stores serving mostly black customers in the Washington and Baltimore area did not accept personal checks while those with mostly white customers did.

Consolidated Stores, the parent company of KB Toys, has denied the allegations.

Brad Wait, Consolidated's senior vice president of human resources, said a small number of stores with high fraudulent check rates do not accept personal checks from customers. ''They are stores monitored by the KB finance office that have fraudulent check rates that have reached a high of 20 percent,'' Wait said. ``They have no information on the demographic makeup of that store. It has nothing to do with demographic makeup.''

The lawsuit, filed on behalf of the center, civil rights attorney Avis E. Buchanan and customer Carolyn Kornegay-Belton, is seeking unspecified punitive and compensatory damage and an injunction against further discriminatory practices.

[Updated 12-17-99]