WHEN IN DOUBT, GO AFTER THE RETAILER: Athletic shoe maker Reebok claims in a federal lawsuit that retail giant Wal-Mart sold a line of basketball shoes that violated Reebok's patent for a three-layer cushioned sole.

Reebok asked that Wal-Mart stop selling its Starter Oxide shoes and notify customers who bought them that they are unauthorized copies of Reebok's DMX Reflex shoe, and should be returned. Reebok's lawsuit, filed in U.S. District Court in Boston in December, also seeks unspecified damages and legal costs.

Wal-Mart denies the allegations. Spokeswoman Mary Heires said the company sold out of the Oxide shoes and no longer carries them. It does carry other basketball shoes under the Starter label.

Heires said Nike Inc. bought the rights to the bankrupt Starter brand last year, and indemnified Wal-Mart against any damages in the case. Nike is not named as a defendant in the lawsuit.