UPDATE 2-Antofagasta's Q1 copper output falls, repeats target

* Q1 copper output down 2.4 pct to 111,900 tonnes

* Reiterates 2009 copper output target of 433,000 tonnes

* Molybdenum output off 5.5 pct at 1,700 tonnes

* Shares rise 3.6 pct, in line with mining index

(Adds share price, reiterates outlook, more details)

By Eric Onstad

LONDON, April 30 (Reuters) - Chilean copper miner Antofagasta Plc (ANTO.L) posted a drop in its first-quarter copper output on Thursday and higher costs, but the output figure was in line with a lower full-year forecast.

The London-listed group said copper production in the first three months of the year was 111,900 tonnes, down 2.4 percent on the same period last year.

The quarterly output was slightly more than a quarter of the full year target of 433,000 tonnes.

Thursday's statement did not mention the target, issued when the firm released annual results last month, but a spokesman said it was unchanged.

At the time Antofagasta said 2009 copper production was forecast to fall 9.4 percent, mainly due to lower grades at its flagship Los Pelambres mine.

The company -- which owns three copper mines in Chile -- said its expansion project at Los Pelambres and development of the new Esperanza mine were both on schedule.

The firm's shares, which have gained 35 percent this year, were up 3.6 percent at 573 pence by 1028 GMT, when the London market's mining index .FTNMX1770 was up 3.2 percent.

COSTS JUMP

Molybdenum production fell 5.5 percent to 1,700 tonnes compared with the same quarter last year.

Cash costs in the quarter jumped 35 percent to 97.5 cents per pound from 72.2 cents in the same period of 2008, mainly due to lower by-product credits after molybdenum prices fell.

This was higher than the 94 cents forecast for 2009 as a whole, but the firm said costs were in line with the year-to-date forecast.

The firm did not give an update of its financial situation after saying last month it had a net cash position of $2.9 billion.

In March it posted a sharper-than-expected 39 percent fall in 2008 net profit due to a slide in metals prices, but pleased shareholders by boosting dividends by over a fifth. [ID:nL9197127] (Editing by Dan Lalor, Greg Mahlich)