Aubrey McClendon, the oil and natural gas wildcatter ousted from Chesapeake Energy Corp. last year, is exploring a purchase of Freeport-McMoRan Inc.’s operations in California for as much as $5 billion, people with knowledge of the matter said.

McClendon’s American Energy Partners LP has been seeking to raise capital to fund the potential deal, said the people, who asked not to be identified because the matter is not public. American Energy, which has raised $13 billion since it was started last April, would fold the assets into a newly created operating unit, the people said.

The deal isn’t finalized and Freeport-McMoRan is talking to other potential buyers, the people said.

McClendon has used American Energy to acquire shale basins and pipeline networks from Appalachia to the Great Plains. A purchase of the California oil and gas fields would be the largest acquisition yet for the company, which in June agreed to buy acreage in the Marcellus, Utica, and Permian Basins in three deals worth a total $4.25 billion.

Charlie Rexford, a spokesman for American Energy, declined to comment. Phoenix-based Freeport-McMoRan didn’t respond to a request for comment.

Freeport-McMoRan declined 0.4 percent to $32.17 at 9:34 a.m. in New York. The shares have dropped 15 percent this year.

The world’s largest publicly traded copper producer has been selling assets to reduce debt incurred in its $9 billion acquisitions of Plains Exploration & Production Co. and McMoRan Exploration Co.

At a conference in June, chief financial officer Kathleen Quirk said Freeport-McMoRan would continue to evaluate whether to keep its California operations or sell them.

California “has been a steady cash flow producer. It’s a good asset,” Quirk said at the time. “We will continue to evaluate whether it makes sense to keep that as a way to fund ongoing growth” or “monetize that in some fashion.”

Freeport-McMoRan’s onshore operations in California include 16,000 net acres in the San Joaquin Basin and control of the Arroyo Grande Field, an oil-producing property in San Luis Obispo County, according to the company’s website.

At Chesapeake, which he helped found, McClendon amassed a shale empire that rivaled Exxon Mobil Corp.’s before he was dismissed last year amid conflict-of-interest probes and a shareholder revolt led by billionaire Carl Icahn. American Energy’s various subsidiaries will eventually go public, McClendon said last month.

Subscribe Now

Complete access to real-time information and analysis of news and trends in the industry.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.