"BHP Billiton expects to recognize an impairment charge of approximately US$4.9 billion post-tax (or approximately US$7.2 billion pre-tax) against the carrying value of its Onshore US asset," the firm said. " This charge will be recognized as an exceptional item in the financial results for the half year ended 31 December, 2015."
CEO Andrew Mackenzie said BHP Billiton responded quickly by "dramatically" scaling down its operating and capital costs. He said the number of onshore rigs in the United States had been reduced from 26 a year ago to five by the end of the current quarter.
"While we have made significant progress, the dramatic fall in prices has led to the disappointing write down announced today," Mackenzie added.
The latest is the British-Australian miner's third writedown in the United States, after a $2.8-billion cut in July 2015 and another $2.8-billion in 2012.
The mining giant entered the oil and gas market with a $20.6-billion investment in 2011.
