United Steelworkers leaders, representing employees at about two-thirds of U.S. refineries, instructed members to reject the first three-year contract proposed by companies on Friday, describing the offer as “offensive.” Gary Beevers, the USW international vice president who manages the union’s oil sector, told all local units to turn down the proposal made collectively by companies including Chevron Corp. (CVX) , Exxon Mobil Corp. (XOM) , Marathon Petroleum Corp., Royal Dutch Shell Plc (RDSA) and Tesoro Corp. (TSO) , a telephone message distributed to members on Friday shows. Negotiations between the USW and refiners began this week. The current contract expires Feb. 1. Oil workers are asking for bigger pay raises and better benefits as U.S. oil refiners cash in on the cheapest oil in almost six years. The market value of U.S. refiners has jumped as plants take advantage of a domestic shale boom that has propelled the nation’s […]