BHP Billiton (LON:BHP) saw profits fall 37 percent in the second half of 2017, after recording an exceptional loss of $2 billion.

Profit for the half year to December came in at $2.0 billion, down from $3.2 billion reported in the same period the year before. The mining group attributed this to the $2 billion hit relating to the failure of the Samarco dam, as well as the effect of US tax reform.

However, underlying attributable profit climbed 25 per cent to just over $4 billion over the period, driven by an increase in sales of both copper and oil.

BHP cut net debt by 23 percent to $15.4bn from $20.1bn at the close of the last financial year, and announced a bumper dividend of 55 cents per share, up 38 percent or 15 cents per share from a year ago.

Chief executive Andrew Mackenzie said: “Higher commodity prices and a solid operating performance delivered free cash flow of US$4.9 billion. We used this cash to further reduce net debt and increase returns to shareholders through higher dividends.

“We are on track to deliver further productivity gains of US$2 billion by the end of the 2019 financial year as we secure improvements in both operating and capital productivity, aided by smarter technology application across our value chain.”

Shares in BHP Billiton (LON:BHP) are currently down 3.19 percent at 1,512.20 (0819GMT).