(Adds union statement)
Feb 13 (Reuters) - The United Steelworkers union (USW) saidno new strike notices were issued on Friday as the largest U.S.refinery strike since 1980 reached its 13th day.
About 5,400 workers at 11 plants, including nine refineriesaccounting for 13 percent of U.S. production capacity, were onstrike with no signs of an immediate end.
The last round of strike notices were issued a week ago onFriday, Feb. 6, when the union told BP Plc that workerswould walk off their jobs the following day at refineries thecompany operates in Indiana and Ohio.
Both the union and U.S. refinery owners are preparing forthe renewal of talks on Wednesday.
"We're still fulfilling the information request from the USWand looking forward to resuming negotiations next week," saidRay Fisher, spokesman for Shell Oil Co, the U.S. arm of RoyalDutch Shell Plc , the lead company negotiator.
In addition to the information request, the union iswaiting for Shell's response to a counterproposal made lastweek. No details about the counterproposal have been released.
The information request, which Shell has called extensive,focuses on the use of non-union contract workers to performday-to-day maintenance in refineries.
Workers hired by the companies contracted to do regularrefinery maintenance are less qualified than union workers, theUSW has said.
Also, on Friday, the union said unfair labor practicescharges have been filed with the U.S. National Labor Boardagainst refineries operated by BP-Husky, LyondellBasellIndustries NV, Marathon Petroleum Corp andTesoro Corp where strikes are taking place.
Only one refinery, Tesoro's 166,000-barrel-per- day (bpd)plant in Martinez, California, near San Francisco, has been shutdue to the strike. Tesoro shut the refinery on Feb. 6, becauseone-half of the plant's production was already out due a plannedmultiunit overhaul.
The company said on the Thursday the Martinez plant willremain shut until the strike ends.
Since the talks started on Jan. 21, sticking points haveincluded the use of nonunion contractors and how to monitorworker fatigue. Wage increases and health benefits are also onthe table.
The USW is seeking a three-year, industrywide pact thatwould cover 30,000 workers at 63 U.S. refineries that togetheraccount for two-thirds of domestic capacity.
Companies have called on trained temporary replacementworkers to keep their plants running at nearly normal levels.
Refineries affected by the strike have reported malfunctionssince the walkout began on Feb. 1.
A 70,000-bpd gasoline-producing fluid catalytic crackingunit was shut earlier this week at Shell's 327,000-bpd refineryin the Houston suburb of Deer Park, Texas. (Reporting by Erwin Seba in Houston; Editing by Jeffrey Benkoeand Christian Plumb)