Analysts had been expecting the company to average around 700,000 barrels of oil a day during 2012 – a 9 per cent rise on last year’s output. But the explorer said production would only increase by 3 per cent this year.
News of the loss came as it revealed it faces a fine over allegations that it rigged electricity prices in the US and a separate probe by US authorities into payments made to Middle East investors.
The US stock markets end the day mostly unchanged after a two-day shutdown because of Superstorm Sandy.
Barclays reports a pre-tax quarterly loss of £47m, as it reveals two new official investigations into its conduct in the US.