Feb 6 (Reuters) - Barrick Gold Corp ABX.TO said on Tuesday it expects to record an estimated pre-tax impairment of $429 million at its Pascua-Lama project in South America in the fourth quarter due to reclassifying its gold reserves.
Barrick, the world's biggest gold miner by output, also said it had formed a working group with Shandong Gold 600547.SS to study a potential partnership at Pascua-Lama, which straddles the border of Chile and Argentina.