(Corrects paragraph 9 to say that the company and union met after April 30 instead of saying they had not)
By Erwin Seba
HOUSTON, May 9 (Reuters) - The reopening of a portion of a Deer Park, Texas, petrochemical tank farm after a massive mid-March fire may lead to the end of a lockout of union workers at a neighboring Dow Inc plant, said four people familiar with the matter.
A March 17 blaze at Mitsui & Co's Intercontinental Terminals Co (ITC) site halted customer access to its undamaged storage tanks and its docks. The fire led to wider disruptions that limited the operations at chemical and refining plants along the Houston Ship Channel.
While the ITC site was out of commission, Dow locked out about 230 hourly workers represented by the United Steelworkers union (USW) on April 22 amid labor contract talks. The plant had relied on ITC for chemical feedstocks and shipping services.
On May 2, authorities allowed ITC to reopen its docks. Dow, which has been operating with primarily salaried employees since the lockout, began boosting production a few days later, the sources said.
"We will continue with our current staffing model as we respond to improved conditions post the ITC tank terminal event," said Dow spokeswoman Ashley Mendoza.
Dow and USW officials met at least twice this week with a federal mediator in an attempt to restart negotiations, Mendoza said.
"The company is willing and has offered to negotiate with the union on a continual basis until our differences are resolved," she said. Union workers will be able to return once an agreement has been reached, she said.
USW officials declined to discuss the negotiations.
Prior to the meetings this week, the two sides met on April 30 with the mediator.
Workers at the Dow plant have twice rejected the company's proposed contract terms. In the first vote, 96 percent of the members rejected the company's proposal, and that widened to 98 percent rejection on the second try, the union has said.
Local, state and federal agencies are investigating what caused the ITC fire, which spread from a single storage tank on March 17 to 10 other tanks over the next two days and required hundreds of emergency workers and fire specialists to extinguish.
Dow acquired the 900-acre (364-hectare) Deer Park site when it bought Rohm and Haas in 2009. The plant makes chemicals used in the production of plastics. (Reporting by Erwin Seba; Editing by Peter Cooney)