WASHINGTON (Dow Jones) -- Asarco LLC is asking for an additional three months to file a reorganization plan to deal with its labor unions and to address its asbestos and environmental liabilities, according to a news report from the Dow Jones Newswire.

The mining company is asking the judge overseeing its bankruptcy case for an extension to Jan. 5, 2007, of its sole right to develop a Chapter 11 plan. The company also wants an extension of its exclusive right to lobby its creditors to accept a plan through March 9, 2007.

Asarco's current exclusive filing period ends Oct. 6.

Companies operating under Chapter 11 must submit a plan to the court outlining how creditors will be paid. Exclusive periods prevent other groups from submitting rival plans and allow a firm to keep control of its bankruptcy case.

In court papers, Asarco said it needs the extension because of the complexity of the issues it has faced since seeking bankruptcy protection in April 2005.

For instance, Asarco said it couldn't begin restructuring its business until months after filing for bankruptcy because of a four-month strike by workers at some of its U.S. facilities. About 1,500 company employees went on strike last year, threatening Asarco with collapse before the workers returned to work in December.

The 107-year-old copper mining company is also the subject of more than 75,000 asbestos-related personal-injury claims and is working with federal and state governments on environmental cleanups at 94 sites in 21 states.

"Any one of the issues, whether it be environmental, asbestos, bond debt or labor unrest, makes any chapter 11 case difficult, but the combination of all four issues makes this case particularly challenging and justifies an extension of exclusivity," the company said in court papers.

A bankruptcy court hearing on the company's request hasn't yet been scheduled.

Asarco is a Tucson, Ariz.-based integrated copper mining, smelting and refining company with nearly 2,000 employees, primarily in Arizona and Texas.

The company also owns the defunct lead smelter in East Helena.

Asarco, a subsidiary of copper giant Grupo Mexico SA filed for Chapter 11 on April 11, 2005, in U.S. Bankruptcy Court in Corpus Christi, Texas.