The United Steelworkers union (USW) said on Friday Shell Oil Co is delaying progress on important issues in negotiations for a new national agreement covering 30,000 U.S. refinery and chemical workers, according to sources familiar with the talks. FILE PHOTO: A Shell gas station is shown in Encinitas, California January 25, 2016. REUTERS/Mike Blake Shell spokesman Ray Fisher declined to discuss specifics about negotiations. “We look forward to the bargaining process working through to its completion and a conclusion that can be satisfactory with all parties,” Fisher said. Shell, the U.S. arm of Royal Dutch Shell Plc ( RDSa.L ), is the lead negotiator for refinery, petrochemical and pipeline companies in talks to replace the current contract that expires on Feb. 1. The sources said talks between the two sides have become heated over a USW proposal to replace non-union contract workers, who perform much of […]