Freeport-McMoRan Copper & Gold Inc. said Tuesday that fourth-quarter profit rose 16 percent on a combination of rising sales and lower copper-production costs, and the mining company’s stock rose.

Net income was $743 million, 78 cents per share, compared with $640 million, or 67 cents per share, a year earlier. Excluding one-time items such as a charge for environmental costs, the company said it would have earned 74 cents per share, beating the forecast of 71 cents per share among analysts surveyed by FactSet.

Revenue increased 8 percent to $4.51 billion. Analysts expected $4.50 billion, on average.

Copper sales rose 18 percent, gold sales jumped 91 percent, and molybdenum sales gained 11 percent, the company said.

Cost of producing one pound of copper dipped to $1.54 from $1.57 a year earlier, reflecting lower employees costs partially offset by higher mining costs.

In December, the company announced that it will buy Plains Exploration & Production Co. and McMoRan Exploration Co. for $20 billion in total, including the assumption of debt. The deals are expected to close in the second quarter.

For the full year, Freeport-McMoRan earned $3.04 billion, or $3.19 per share, compared with $4.56 billion, or $4.78 per share, in 2011.