The miner, which keeps its books in U.S. dollars, said Wednesday it earned US$107.3 million or 23 cents per share for the quarter ended Sept. 30 compared with a profit of $90.9 million or 20 cents per share a year ago.
Sales revenue totalled $724.8 million, up from $651 million.
Copper sales amounted to 77,396 tonnes for the quarter, up from 71,443 tonnes a year ago, while gold sales increased to 48,889 ounces, up from 47,458 in the third quarter of 2011.
Earlier this year, First Quantum sold its operations in the Democratic Republic of Congo to Kazakhstani miner Eurasian Natural Resources Corp. for $1.25 billion.
First Quantum had written off the value of the assets in 2010 after its operations in Congo were nationalized by the government of the mineral-rich central African country.
The company has said it will focus its efforts on Zambia where it has its flagship Kansanshi mine and is developing other projects including a new mine and smelter.
Shares in the company, which reported its results after the close of markets, were up 28 cents at $22.45 on the Toronto Stock Exchange on Wednesday.