Antofagasta, the Chilean copper miner, posted an 86% hike in full-year profits to $2.9bn (£1.5bn), but warned that the record copper prices seen in 2006 might not be repeated.
The FTSE 100 company said it benefited from record copper prices last year, with copper production above forecasts at all three mines.
Production of molybdenum, which is used to harden steel, rose 13%. Sales grew 58% to $3.9bn.
Marcelo Awad, chief executive, said: "The copper market has declined somewhat since mid-December, although more recently appears to have rebalanced.
"We currently expect the copper and molybdenum markets to remain well above historical levels in 2007 with the potential, through the year, for copper prices to recover from recent weakness and molybdenum prices to continue on their upward trend of recent months."
But he added: "The exceptional average copper price of 2006 might not be repeated and the recent volatility that has characterised the market is likely to continue."
The group will pay a total dividend of 48.2 cents a share, up 119% from last year, including a special dividend of 38 cents.
Analysts welcome the dividend as better than expected, and reflecting a strong cash flow.
The company also said it had diversified out of Chile in 2006 with new ventures for exploration in Pakistan, Colombia and Ecuador.
But analysts at Teather & Greenwood warned: "Looking forward, it will be difficult to beat this year's results as production from the mines is expected to be flat year-on-year, though the acquisition of the minority interest in the El Tesoro mine should mean that attributable production is slightly up.
"However, we expect both copper and molybdenum prices to fall slightly from 2006 averages."