The largest U.S. refinery strike in 35 years entered its fourth week on Sunday as workers at 12 refineries accounting for one-fifth of national production capacity were walking picket lines. Sources familiar with the negotiations said talks may resume by mid-week to end the walkout by 6,550 members of the United Steelworkers union (USW) at 15 plants, including the 12 refineries. Representatives of both sides said no date has been set to restart negotiations, however. The strike comes as U.S. workers seek more pay in a strengthening economy. Wal-Mart Stores Inc has said its U.S. workers will get a raise to at least $9 an hour, while West Coast port workers have reached a tentative deal for a new contract after a months-long dispute. The refinery work stoppage began on Feb. 1 when talks for a new three-year contract between the USW and lead oil company […]