Rio Writes Down $4.7 Billion of Unit Operating Mongolia Mine

Rio Tinto Group wrote down the value of a “cash-generating” unit developing Mongolia’s Oyu Tolgoi copper and gold mine by $4.7 billion as an impasse with the government persisted over starting underground operations.

The $1.1 billion pretax impairment of goodwill and $3.6 billion property and equipment writedown are the result of Oyu Tolgoi remaining an open-pit only operation, Rio Tinto said in its annual report published yesterday. A further $800 million may be written down should underground mining fail to begin in the next 12 months, Rio said.