Freeport also said on Monday that it appointed Gerald Ford non-executive chairman, effective Dec. 31. Ford has been the company's lead independent director since 2013.
Freeport entered the oil and gas business in 2013 with the acquisitions of Plains Exploration and McMoRan Exploration for $9 billion. The move raised eyebrows because Moffett was also McMoRan's largest individual shareholder and its chief executive.
In his new role, Moffett will receive an annual consulting fee of $1.5 million, Freeport said in a regulatory filing.
Moffett's departure comes a couple of months after Freeport scrapped its unusual "Office of the Chairman" structure.
The "office," which comprised Moffett, Chief Executive Richard Adkerson and the company's oil and gas business President James Flores, was seen as drowning out the voice of the lead independent director.