(Adds production, costs, forecast, free cash flow)
TORONTO, Oct 29 (Reuters) - Goldcorp Inc , the world's biggest gold miner by market value, reported a bigger third-quarter loss and missed estimates, as an inventory writedown and declining bullion prices offset lower costs and a 42 percent jump in production.
The Vancouver-based miner on Thursday also confirmed its 2015 forecast for production at the high end of a range between 3.3 million and 3.6 million ounces of gold, all-in sustaining costs of $850 to $900 an ounce and capital spending of $1.2 billion to $1.4 billion.
Its net loss widened to $192 million, or 23 cents a share, from $44 million, or 5 cents a share, in the same period last year.
The adjusted loss was $37 million, or 4 cents a share, compared with an adjusted profit of $70 million, or 9 cents a share. The adjusted loss included a reduction in the carrying values of inventory stockpiles of $40 million, or 5 cents a share, and noncash, stock-based compensation costs of about $14 million, or 2 cents a share.
Analysts, on average, expected Goldcorp to earn an adjusted profit of 4 cents a share, according to Thomson Reuters I/B/E/S.
Free cash flow was $243 million, compared with a negative $355 million in the prior-year period.
All-in sustaining costs to produce an ounce of gold, which includes sustaining capital, exploration and general expenses, fell to $848 in the quarter from $1,066 last year.
In the quarter, gold production increased to a record 922,200 ounces from 651,700 as the average realized price fell to $1,114 per ounce from $1,266 ounce.
In September, the company trimmed its full-year production estimate for its Eleonore mine in Canada. Due to lower gold grades from unexpected folds and faults in the ore body, Goldcorp clipped the forecast to 250,000-270,000 ounces of gold from 290,000-330,000 ounces.
Goldcorp decided to cut its dividend by 60 percent, it said in July, to fortify its financial position in a volatile gold market. (Reporting by Susan Taylor; Editing by Jeffrey Benkoe)