HOUSTON, Jan 29 (Reuters) - Lead industry negotiator Royal Dutch Shell Plc said on Thursday it was "optimistic" a new three-year agreement could be reached with a union representing hourly workers at 63 U.S. refineries that account for two-thirds of U.S. refining capacity.
In a message to members, the United Steelworkers union (USW) did not share Shell's optimism, pointing to the approaching expiration of the current three-year agreement at 12:01 a.m. on Sunday in the time zone where each refinery is located.
"Still no new offer from the industry," the USW message read. "Clock is ticking. Day of action was a huge success and Oilworkers are ready to stand up and fight back."
USW locals carried out protests in support of the union's contract proposals in front of refineries across the country on Wednesday. The union and refineries have both prepared for a possible strike, which the union signaled on Monday may be needed to win concessions from the oil companies.
The last nationwide refinery workers strike was in 1980 and lasted for three months.
Shell is leading the talks on behalf of companies that own U.S. refineries including majors such as Exxon Mobil Corp and BP Plc and smaller companies such as HollyFrontier Corp and Delek.
"We remain optimistic that a mutually satisfactory agreement can be negotiated with the United Steelworkers union (USW)," said Shell spokesman Ray Fisher in a statement issued on Thursday night.
The USW is seeking annual pay raises double those of the last agreement. It also wants work that has been given in the past to non-union contractors to start going to USW members, a tighter policy to prevent workplace fatigue, and reductions in members' out-of-pocket payments for healthcare.
The USW has rejected two contract proposals from oil company negotiators since talks began on Jan. 21. At least five contract proposals were rejected during the talks in 2012 for the current agreement.
In 2012, an agreement was announced only hours before the contract was set to expire. During bargaining in 2009, the deadline for the contract's end was extended three times before an agreement was announced.
Reporting by Erwin Seba; Editing by Tom Hogue