 Core Main Inc. CNM, -0.44 rallied 8 in premarket trades after the St. Louis-based distributor of water, wastewater, storm drainage and fire protection products raised its earnings outlook and handily beat profit expectations for the third quarter. Core Main said it earned 111 million, or 65 cents a share in the three months ended Oct. 30, up from 64 million, or 39 cents a share, in the year-ago period. 