ExxonMobil warns of $30bn writedown of shale assets amid energy price slump

Announcement follows record quarterly loss of $680m, its third quarterly deficit in a row

ExxonMobil has warned it may write down the value of its US shale assets by up to $30bn (23.2bn) following a steep drop in global energy prices that has led to the oil giant's third consecutive quarterly loss.

The US oil and gas producer told investors it plans to reassess its North America gas business over the coming months, which could lead to impairment charges as high as $25bn to $30bn if it changes its long-term strategy.