BHP Billiton, the world’s largest mining group, is to reduce the number of shale oil rigs that it is operating in the USA from 26 to 16 by the end of June in response to the fall in the price of oil.

CEO Andrew Mackenzie said: “In petroleum, we have moved quickly in response to lower prices and will reduce the number of rigs we operate in our onshore US business by around 40% by the end of this financial year. However, the revised drilling programme will benefit from significant improvements in drilling and completions efficiency. Shale volumes are still forecast to grow by about 50% over the coming year.”

Mr Mackenzie said that, while the Anglo-Australian group’s drilling operations will focus on its Black Hawk field in Texas, “we will keep this activity under review and make further changes if we believe that deferring development will create more value than short-term production”.

BHP reported that its iron-ore output rose by 16% in the last quarter of 2014 (compared to a year earlier), reaching a total of 56.4 million tonnes. However, the price of iron ore — one of the group’s core commodities — fell by 47% last year because of a global supply glut and softening demand from China.

Mr Mackenzie said that the company remains committed to its planned de-merger, which is due to be completed by the end of the financial year. This will see a new independent company called South32 created by spinning-off non-core assets, including aluminium, manganese and silver, plus selected coal and nickel operations.