The Supreme Court Monday rejected an appeal by Microsoft Corp. and a unit of Best Buy Co. Inc. to dismiss a lawsuit alleging violation of racketeering laws through fraudulently signing up customers for Microsoft’s online service.

The companies asked the justices to overturn a May ruling by the San Francisco-based 9th U.S. Circuit Court of Appeals, which said the civil suit could proceed. The Supreme Court is letting that ruling stand, which means the class action lawsuit involving thousands of consumers with complaints against the companies will be litigated in federal district court.