Fluor Buys Rest of Ownership in Mining Concern : Acquisition: The Irvine-based engineering and construction company will pay $125 million for sole control of a lead-producing operation it co-founded in 1986 with Homestake Mining Co.

Fluor Corp. said Monday that it has agreed to buy the remaining 42.5% ownership in the largest primary lead-producing firm in North America for $125 million from Homestake Mining Co.

The agreement to acquire the remainder of the Doe Run Co. was announced in statements issued separately by Fluor, the Irvine engineering and construction giant, and by Homestake Mining Co., a major gold-mining company in San Francisco.

Pending customary antitrust clearance, the proposed cash sale, which also would release Homestake from responsibility for Doe Run’s liabilities, is expected to close within 90 days.

Industry analysts said they believe that Fluor, which previously owned 57.5% of Doe Run, wants to acquire the rest of the company in order to sell the entire lead-mining and production concern on the open market.

“(Fluor) has been actively trying to sell its percent ownership in Doe Run during the last year but was unable to get its price,” said Kathy Maag, a securities analyst with Duff & Phelps in Chicago. “I believe the plan is still to sell the unit, but it is easier to sell as a whole rather than have someone buy into a partnership.”

Fluor officials said that Doe Run “is not on the block” and that currently Fluor is not in negotiations with any potential buyer.

But Fluor did acknowledge that it considers Doe Run an investment rather than an essential part of its core engineering and construction business.

“This purchase does not signal a change in Fluor’s long-term strategy of focusing on engineering and construction through Fluor Daniel, its (engineering and construction) unit,” Les G. McCraw, Fluor’s chief executive officer, said in a statement. “Full ownership merely enhances Doe Run’s investment value and increases the strategic options available to Fluor.”

One option would be to sell. Fluor spokesman Rick Maslin said that last year Fluor received “a number of inquiries from people who wanted to buy 100% of (Doe Run),” while no one expressed interest in buying only part of the firm.

“If there was an offer that was attractive and enhanced our shareholder value, we would be interested in it,” Maslin said.

Fluor’s stock closed down 50 cents at $43.50 in trading Monday on the New York Stock Exchange.

Fluor and Homestake, which merged their lead-mining and smelting operations when they founded Doe Run in 1986, said Monday that it had become difficult to jointly run the lead company because of differences in their business goals and strategies. Under the existing partnership agreement, virtually all decisions required approval by both companies.

“The sale will resolve differences of opinion about the direction of the business,” said Harry M. Conger, chairman and chief executive officer of Homestake. “After long discussion, Homestake and Fluor concluded that one company or the other should control Doe Run.”

Janet M. Bley, Homestake’s manager of industrial relations, said that Homestake had made an offer to purchase Fluor’s ownership interest in Doe Run but that “Fluor declined to sell.”

Doe Run, based in St. Louis, generates about 60% of the lead that is marketed in the United States, much of which is used in the making of automobile batteries. Last year, the company made $68 million in operating profit.

Fluor said it now intends to expand Doe Run’s activities into the secondary, or recycled, lead market.