HOUSTON (Reuters) - Union workers at Tesoro Corp's 97,000 barrel per day (bpd) Los Angeles Refinery in Wilmington, California, voted to authorize a strike if talks with company management for a new agreement are unsuccessful, a spokeswoman for the United Steelworkers Union (USW) said on Wednesday.
The local USW union at the Los Angeles Refinery is fourth representing a Tesoro plant to authorize a strike, but no work stoppage is expected before the contract for the Los Angeles Refinery workers expires on April 30.
The contracts for workers at Tesoro's Anacortes, Washington, Mandan, North Dakota, and Martinez, California, refineries expired at the end of January.
Workers at those three refineries have already granted authority to their local leaders to call a walkout if an agreement cannot be reached with management.
The four refineries where workers have voted to authorize a strike account for two-thirds of Tesoro's combined crude oil refining capacity of 666,000 bpd.
A Tesoro representative was not immediately available to discuss the Los Angeles Refinery vote on Wednesday night.
Workers at Tesoro's Kapolei, Hawaii, and Salt Lake City refineries have voted to accept Tesoro's contract offers.
The USW has said Tesoro has made changes in the terms of the current contract without first negotiating with the union.
The Steelworkers union is also seeking stricter safety protections at Tesoro's refineries. An April 2010 explosion at the company's Anacortes refinery claimed the lives of seven workers.
(Reporting by Erwin Seba; Editing by Ed Lane)