Freeport-McMoRan Inc, the U.S. miner that was targeted by activist investor Carl Icahn earlier this year, is planning to run an auction process for its oil and gas assets in early 2016, according to people familiar with the matter.

The process would be the company's first concrete move to end its ill-fated foray into oil and gas after it said in October it would explore strategic options for the assets, including a spinoff, joint venture or public offering.

Phoenix, Arizona-based Freeport-McMoRan's board has retained investment bank Lazard Ltd to advise on possible sale of the company's entire oil and gas interests, which could be worth more than $3 billion, the people said this week.

The sale process may not result in any deal, the people said. It will, however, help Freeport-McMoRan with valuing the assets, so it can decide which strategic alternative offers the most value, the people added.

The sources asked not to be identified because the deliberations are confidential. Freeport-McMoRan and Lazard declined to comment.

Freeport's big bet on oil and gas came in 2013 with the acquisitions of Plains Exploration and McMoRan Exploration for $19 billion, including debt. The moves were big contributors to the company's heavy debt load. Since these acquisitions, oil prices have roughly halved.

Freeport-McMoRan's energy division includes assets in the Deepwater Gulf of Mexico, onshore and offshore assets in California and in the Haynesville natural gas shale formation, along with other natural gas assets in Louisiana.

Shedding the oil and gas business would leave Freeport-McMoRan with mainly copper and gold mining assets. Roughly 60 percent of Freeport's $21 billion of revenue in 2014 came from copper, with about 20 percent from oil.

The company's operations include the massive Grasberg copper and gold mine in Indonesia, the Cerro Verde copper mine in Peru and seven copper mines in North America.

Freeport-McMoRan agreed in October to add two new directors to its board as part of a deal with Icahn, who had taken aim at the company's spending, capital structure and executive compensation.

Earlier this month, Freeport-McMoRan suspended its annual dividend and made deeper cuts in capital spending and copper production to deal with a downturn in commodities prices that has entered its fifth year.