 EL DORADO, Ark. and WESTLAKE, Texas, Jan. 28, 2021 GLOBE NEWSWIRE -- Murphy USA Inc. NYSE: MUSA and Core-Mark Holding Company, Inc. NASDAQ: CORE announced today that they have entered into a new five year supply agreement whereby Core-Mark will continue to serve as the primary wholesale distributor to Murphy USA, delivering over 75 of the merchandise sold in their stores. 