California Attorney General Bill Lockyer has filed a lawsuit to force top makers of potato chips and french fries to warn consumers about a potential cancer-causing chemical found in the popular snacks...Lockyer sought an injunction to stop restaurant chains such as McDonald's Corp. and Wendy's International Inc. [pat of Wendy's/Arby's Group] from selling french fries without some form of warning. Also named were producers of potato chips and other packaged potato products like PepsiCo's, Frito-Lay Inc. and Procter & Gamble Co., makers of Pringles chips...Other defendants named in the suit include Burger King Corp., KFC Corp., a unit of Yum Brands Inc., for its KFC Potato Wedges, Kettle Foods Inc., makers of Kettle chips...and Cape Cod Potato Chips Co...,a unit of Lance Inc. [the other defendant, not mentioned in this article, is Ore-Ida frozen potato products, part of Heinz]