(Adds Shell statement, analyst comment)
HOUSTON, Jan 31 (Reuters) - Union negotiators rejected thelatest offer from oil companies covering workers at 63 U.S.refineries on Saturday night, just hours before a strikedeadline, according to a message sent to union members.
The United Steelworkers union (USW) said in the text messagesent to members that the latest offer was "insulting and failsto address issues that matter to members."
Royal Dutch Shell Plc the lead negotiator for U.S.refinery owners, said it does not comment on details of labornegotiations.
"We remain committed to resolving our differences with theUSW at the negotiating table," Shell spokesman Ray Fisher.
This is the fourth contract proposal rejected by the USWsince negotiations for a new three-year agreement began on Jan.21. It comes just hours before the contract is set to expire at12:01 a.m. on Sunday.
The Steelworkers issued strike notices on Friday night toseveral U.S. refineries where contracts expire on Sunday. Whilethe current national agreement expires on Sunday, each refineryhas an individual contract based on the national agreement.
A strike notice is legal notification of a possible strikeby a labor union at that location. It does not mean that astrike will take place at that location.
"All of the locals that have contracts expiring on Feb. 1were instructed to issue strike notices to the companies," oneof the sources said.
The sources did not know which refineries received thenotices, but only those plants where the local contract expiresat 12:01 a.m. local time on Sunday in the time zone where eachrefinery is located.
Exxon Mobil Corp said its refinery in Beaumont,Texas, received a strike notice.
USW International Vice President Gary Beevers, who isnegotiating on behalf of the union, will decide at whichrefineries strikes will take place after the contract expires.
The USW is seeking annual pay raises double those of thelast agreement. It also wants work that has been given in thepast to non-union contractors to start going to USW members, atighter policy to prevent workplace fatigue, and reductions inmembers' out-of-pocket payments for healthcare.
The three-year national contract covers about 30,000 hourlyworkers at 63 U.S. refineries that account for 64 percent ofnational refining capacity.
The drop in oil prices since this summer may have cut theunion's ability to win its objectives, said an oil industryanalyst.
"I think the union would have had a lot more leverage sixmonths ago when the price (of oil) was $100 a barrel," saidAndrew Lipow, president of Lipow Oil Associates in Houston. "Butnow, when the industry is facing hard times and layoffs havebeen announced, their bargaining power is limited."
West Texas Intermediate crude delivered at the Cushing,Oklahoma, oil hub finished on Friday at $47.76 a barrel.
Oil prices rose more than 8 percent on Friday due to anattack by Islamic State militants toward the Iraqi oilproduction center of Kirkuk.
Lipow doesn't expect oil or gasoline prices will go up dueto a strike.
"Attacks on Kirkuk will drive up prices, but a strike by theUSW will not," he said. (Reporting by Erwin Seba; editing by Bernard Orr)
