A federal judge on Monday refused to allow an immediate appeal of his dismissal of RICO counts from a class action suit charging Wal-Mart Stores Inc. with illegal employment practices.

The suit, filed four years ago, alleges that Wal-Mart knew its housekeeping contractors routinely hired illegal aliens and subjected them to adverse work conditions, such as making them work long hours at substandard pay and locking them inside Wal-Mart stores at night.