Copper mining giant Antofagasta (ANTO) beat its full-year production forecasts for 2009, but failed to keep speed with its 2008 levels as the downturn in market prices took its toll.

The FTSE 100 (UKX) group recorded output of 442,500 tonnes over the last twelve months, ahead of the original forecast of 433,000 tonnes. However, it failed to reach 2008 levels of 477,700 as a result of a downturn at it Los Pelambres mine and unfavourable copper prices.

Annual production at Chilean Los Pelambres was 311,600 tonnes, compared with 339,200 tonnes a year earlier. The downturn in output was caused by higher levels of harder primary ore and a decrease in ore grades, the company said. However, on a positive note, the fourth quarter enjoyed a 7.8% rise in payable copper production over third quarter levels to 80,000 tonnes.

In contrast, molybdenum production, used in steel alloys, was down 4.7% in the final three months of 2009 from the previous quarter as a result of marginally lower ore grades. Annual production however was largely unchanged from 2008 at 7,800 tonnes.

Meanwhile, copper prices averaged 234.2 cents per pound in 2009, down from 315.3 cents per pound for the 2008 full year. Antofagasta's full year cash costs for the mine rose to 80.4 cents per pound compared with 57.3 cents per pound for 2008 as a result of lower molybdenum market prices, it added.

Nevertheless, Antofagasta looked to assure investors that 2010 would prove more fruitful, with copper output from the mine forecast to be 407,000 tonnes, while molybdenum production is to rise to 9,500 tonnes.

Construction work on the mine was completed by the close of 2009, with a ramp up to the increased plant throughput level of 175,000 tonnes per day taking place during the first quarter of this year, the group said.

The South American copper producer also suffered a downturn at its El Tesoro operations. Copper cathode production fell almost 6% in the fourth quarter to 24,300 tonnes, while full-year levels of 90,200 tonnes failed to match the 90,800 tonnes seen in 2008. Looking ahead, the company expects to ramp up 2010 full year production output to 96,000 tonnes.

It was much the same story at Antofagasta's Michilla mine, with full year copper cathode production down to 40,600 tonnes from 2008 production of 47,700 tonnes following its suspended operations at the Lince open pit.

However, the outlook for its 2010 production levels was less sparkling, with the company not expecting to exceed levels of 40,000 tonnes for the year.

Dominic O'Kane, mining analyst at Liberum Capital, commented: "What stuck out was the surprising rise in cash costs during the fourth quarter, which increased more than was expected. This shows the inflationary pressure they are under.

"That said, molybdenum contract prices have now been fixed and the spot price is rising so they should be able to enter 2010 on a better footing."

Antofagasta's shares were down marginally to 928p.