Workers at largest U.S. refinery OK deal; Tesoro making progress

HOUSTON, March 17 (Reuters) - More than 700 union workers at the largest U.S. refinery unanimously approved a new contract in a vote at their union hall in Port Arthur, Texas, on Tuesday night, said union officials.

The United Steelworkers union (USW) also said workers at three Tesoro Corp refineries on the West Coast were making progress in finalizing contracts. Return-to-work agreements, usually the final step before ratification votes, were under discussion.

USW members at the Motiva Enterprises Port Arthur, Texas, refinery walked off their jobs on Feb. 21 as part of the nation's largest refinery strike in 35 years.

Port Arthur workers are expected to return to their jobs next week.

"This is a ton of bricks off the backs of our members," said Jeffrey Wright, vice chairman of the Motiva Workman's Committee in USW local 13-423. "Our membership is thankful our international leadership got a good contract."

USW negotiators reached an industry-wide agreement to settle the strike with lead U.S. refinery owner representative Royal Dutch Shell Plc on Thursday. Shell (LSE: RDSB.L - news) is a co-owner of Motiva.

USW-represented workers are also expected to return to work at Motiva's refineries in Norco and Convent, Louisiana, next week.

Workers at Shell's joint-venture refinery in Deer Park, Texas, who were among the first to go on strike when work stoppages began on Feb. 1, are scheduled to vote Thursday on the new contract.

A Tesoro spokeswoman said the company was pleased with the progress being made to end strikes by workers at refineries in Anacortes, Washington, Carson and Martinez, California.

"We look forward to welcoming back our workers and resuming normal operations together," said Tesoro's Tina Barbee.

The USW said BP Plc, Lyondell Basell Industries , and Marathon Petroleum Corp "continue fights on tough local issues." (Reporting by Erwin Seba; Editing by Paul Tait)