The world's second-largest gold miner warned in August it could exceed its gold production cost guidance as miners battle with inflation and rising costs of labor, energy and mining supplies. It said its third-quarter gold output fell due to weak production from its Veladero, Carlin and Turquoise Ridge mines. Adds Q3 production details, background Oct 13 (Reuters) - Barrick Gold Corp ABX.TO, GOLD.N on Thursday reported a fall in third-quarter gold output from the previous quarter and said it expects full-year gold production to be at the low end of the range it forecast earlier.