Saudi Arabia gained the whip hand yesterday in its battle against America's shale industry as new figures showed oil production by non-Opec members is set to crash next year by the largest amount in 24 years.

Sharply lower oil prices are set to trigger a slide in production of half a million barrels from outside the Opec cartel to 57.7 million barrels a day in 2016, the International Energy Agency said in its monthly report.

It offered one of the clearest signs yet that Saudi Arabia's attempts to knock out American shale gas production appear to be working.