Jan 15 (Reuters) - BHP Billiton (L:BLT) Ltd BHP.AX :
* Onshore US asset review BHP.AX
* Expects to recognise 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 assets
* Says charge will be recognised as an exceptional item in the financial results for the half year ended 31 December 2015.
* The company has now also reduced its medium and long-term gas price assumptions"
* US gas price remains low as industry-wide productivity improvements have resulted in higher than expected supply at lower cost
* The oil and gas industry has recently experienced significant volatility and much weaker prices."
* Says the increased volatility in prices has also increased the discount rates applied by BHP Billiton
* Says group will reduce the number of operated rigs in its onshore US business from seven to five in the March 2016 quarter
* Group will reduce the number of operated rigs in its onshore US business from seven to five in the March 2016 quarter"
* Dramatic fall in prices has led to the disappointing write down announced today"
* We are well positioned to respond to a recovery"
* Says "we remain confident in the long-term outlook and the quality of our acreage"
* Impairment will reduce onshore US net operating assets to approximately US$16 billion"
* Investment and development plans for the remainder of the 2016 financial year are under review"
* Although we expect prices to improve from their current lows, we have reduced our oil price assumptions for the short to medium term"
* Source text for Eikon ID:nASX4Fwm33
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