BHP Billiton has posted a 16% increase in iron ore and metallurgical coal output for the fourth quarter but warned growth containment measures in China could hit demand.

The company’s iron ore output for the quarter stood at 31.2 million tons while its metallurgical coal production was 11 million tons.

Western Australia iron ore achieved its tenth consecutive annual production record, BHP said in a statement.

But the company said “measures designed to reduce growth to more sustainable levels means volatility in commodity end-demand is likely to persist”.

China is BHP’s biggest customer, consuming an estimated quarter of the combined output from BHP and its rival Rio Tinto.