Texas chemical plant that caught fire to close for extended period -document

* Federal, state agencies begin search for blast cause

HOUSTON, Dec 2 (Reuters) - A Texas petrochemical plant, still burning on Monday after a series of explosions last week that injured three and prompted thousands of evacuations, will be out of operation for an extended period, according to a letter to workers viewed by Reuters.

TPC Group Chief Executive Edward Dineen told the plant’s about 175 workers they would be paid through year-end but the facility which makes chemicals used in synthetic rubber and gasoline, would close “for an extended period,” the Friday letter to staff said.

A TPC spokeswoman was not immediately available to discuss Dineen’s message.

The Port Neches, Texas, site has been burning for six days after an explosion that injured three workers and prompted the evacuation of about 60,000 residents over worries storage tanks could ignite and explode. The fire was contained and officials allowed residents to return to their homes on Friday.

By end of the year, “if not sooner, we hope to have a better handle on the situation at (Port Neches), including recovery team needs and potential rebuild team needs,” Dineen said in his letter to workers.

Federal and state investigators have began probing the blasts and ensuing blaze.

Dineen wrote the Houston-based company has just begun the process of working with its insurance carriers on claims from the explosions and fire. The cause remains unknown, he wrote.

Records from the Texas Commission on Environmental Quality, the state’s pollution regulator, show it began investigations of the plant in September 2014 after the company failed to meet carbon monoxide limits between 2011 and 2013. Those investigations have remained open into this year.

TPC received citations from the commission for failure to meet pollution limits on units, failure to maintain required equipment and maintain proper records between 2014 and 2019.

But the regulator rated the company’s performance at the Port Neches site as “satisfactory,” according to a compliance history report provided by the agency on Monday.

The company and fire officials said on Monday there have been no new injuries, air monitoring continues to show no health hazards, and the fire “continues to be contained.”

Workers are checking nearby properties for fallout from the fire and TPC insurance representatives are visiting properties damaged by the initial explosion, which could be felt miles away.

In addition to the company’s staff, another 50 people work at the plant, but are employed by other companies who contract with TPC to provide services such as maintenance of equipment. (Reporting by Erwin Seba; Editing by David Gregorio)