(Adds background, details)
HOUSTON, April 29 (Reuters) - BP Plc and the UnitedSteelworkers union (USW) chapter representing striking workersat the company's Whiting, Indiana, refinery reached a tentativeagreement on Wednesday to end an 11-week work stoppage.
The two sides have to negotiate an agreement on returningthe striking workers to the Chicago-area plant, but aratification vote is expected next week, said Dave Danko,president of USW Local 7-1, which represents the workers.
"We are pleased to have a tentative agreement in place atWhiting and will work towards getting our colleagues back towork as soon as possible," said BP spokesman Scott Dean.
Before the tentative pact can be considered forratification, USW International Vice President Gary Beevers, whooversees the union's national oil bargaining program, mustverify that the proposal conforms to the terms of a nationalagreement reached by the USW and U.S. refinery owners, saidLynne Hancock, union spokeswoman.
After a ratification vote, it can take a week to two weeksbefore workers return to their jobs.
Danko said both sides compromised to make the tentativedeal.
"The company moved in our direction and we moved in theirdirection," Danko said.
Talks had been stalled on the question of bargaining by theunion during the term of the contract.
BP had said it wanted to limit the issues the union couldbargain over so it could more quickly implement policy changes.The union had said it wanted language that would allow it tonegotiate with the company over policies affecting workers onquestions such as safety.
"We reached an agreement that allows the company to becompetitive and preserves the language we wanted," Danko said.
Under the terms of the four-year national agreement, once acontract is ratified the workers are scheduled to receive a 2.5percent pay increase in the first year of the pact, a 3 percentincrease in each of the two following years and a 3.5 percentincrease in the fourth year.
BP has kept the refinery in operation using temporaryreplacement workers.
(Reporting by Erwin Seba; Editing by Andre Grenon and AlanCrosby)