* Antofagasta Q3 output up 9 pct year over year
* Chilean miner on track to meet full-year target
* Annual output seen roughly 700,000 tns in next 2 yrs- CEO
By Clara Ferreira-Marques and Fabian Cambero
LONDON/SANTIAGO, Oct 31 Chilean miner Antofagasta said third-quarter copper output rose almost 9 percent year-on-year, boosted by improved production at its trouble-plagued flagship mine Esperanza and steadier volumes elsewhere.
The London-listed mining group's third quarter was broadly within analysts' expectations, producing 179,800 tonnes of copper, up almost 4 percent on the second quarter.
Antofagasta said that put it on track to meet its full-year target of 700,000 tonnes, having produced 515,800 tonnes in the first nine months of the year.
"Production is stable and we're advancing towards 700,000 tonnes which is the aim this year and probably the level of production for the next two years," CEO Diego Hernandez told reporters as he presented results in Santiago.
Gold production also increased in the quarter, again in line with full-year targets, rising almost 43 percent to 77,400 ounces, thanks to Esperanza.
Esperanza, a key growth project for Antofagasta, has been hit by nagging operational trouble as it ramps up production and in August the miner said it would need to spend another $200 million to $250 million over 2013 and 2014 to improve processes at the copper-gold mine.
Group cash costs, net of by-product credits, came in at 99.3 cents per pound, flat on the previous quarter.
Over the nine months, cash costs were down almost 5 percent, helped by increased by-product credits from higher gold production at Esperanza and improved molybdenum production at Los Pelambres.
"We are expecting Group production of 695,248 tonnes of copper at cash cost of 102.5 U.S. cents/lb of copper after by-products, after adjusting for the better performance at Esperanza," Scotia Capital analyst Tom Meyer said in a note to clients.
Volume growth and healthy margins compared with the rest of the sector have helped Antofagasta outperform its peers in the past months. Copper prices have helped, rising over the reporting period, though they have since eased.
Hernandez said the copper market should remain tight at least until the first semester of 2013.
Under Hernandez, who took over as chief executive in August, Antofagasta has outperformed the UK mining sector this year by more than 8 percent, recovering from the hiccup-prone ramp-up for Esperanza.