TORONTO - Freeport-McMoRan Inc (FCX.N), the world's second-largest copper miner by production, reported a bigger-than-expected jump in fourth-quarter profit on Thursday, lifted by stronger commodity prices and productivity gains.

The Arizona-based company, which formed a framework agreement with Indonesia's government last August to secure a new permit for its massive Grasberg copper and gold mine, said talks were advancing.

"We are continuing to make significant progress in our ongoing negotiations with the Indonesian government to restore long-term stability for our Grasberg operations," Chief Executive Richard Adkerson said in a statement.

Freeport reported an adjusted profit of 51 cents a share, bettering analyst expectations of 45 cents, and revenue of US$5.04 billion.

Average realized prices rose to US$3.21 per pound of copper, from US$2.48 in the same period last year, while the average price of gold rose to $1,285 an ounce from $1,174.

Freeport reported consolidated sales of 1 billion pounds of copper and 593,000 ounces of gold for the quarter. In October, it forecast sales of 1 billion pounds of copper and 625,000 ounces of gold.

For 2018, Freeport expects consolidated sales of 3.9 billion pounds of copper and 2.4 million ounces of gold, including 1 billion pounds of copper and 675,000 ounces of gold in the first quarter.

It sold 3.7 billion pounds of copper and 1.6 million ounces of gold in 2017, matching its twice-lowered estimate.