VOORHEES, N.J.--( BUSINESS WIRE )-- American Water Works Company, Inc. ( NYS: AWK ), the largest publicly traded U.S. water and wastewater utility company, announced today that Moody's Investors Service (Moody's) upgraded American Water and its subsidiary, American Water Capital Corp., from Baa2 to Baa1. Moody's also upgraded the mortgage bonds at New Jersey American Water Co. and Pennsylvania American Water Co. from Baa1 to A3 and revised the outlook from positive to stable.