BHP Billiton has posted a statutory net full-year loss of $US6.385 ($8.3 billion) on significant one-off write-downs.

It is the company's first annual loss since BHP and Billiton merged 15 years ago.

The company was expected to post a $US5.9 billion ($7.7 billion) loss according to the average of 11 analysts' estimates compiled by Bloomberg.

BHP Billiton's slump in profit was largely driven by a 31 per cent dive in revenue due to plunging commodity prices.

The company said weaker commodity prices wiped $US10.7 billion off its pre-tax earnings.

Chief executive Andrew Mackenzie said there were positives in the result, including reduced production costs and increased efficiency.

"We are clearly very disappointed with this result, however, the underlying performance of our business because of this focus on safety and productivity remains and is getting stronger," he told a media briefing.

The FY2016 result is expected to be the BHP Billiton's first annual loss since its merger. ( Bloomberg )

BHP Billiton's results were decimated by billions of dollars in asset value write-downs and other one-off costs.

The major costs came from cutting the value of its US shale oil and gas assets ($US4.9 billion), the Samarco iron ore disaster in Brazil ($US2.2 billion) and money set aside for global taxation reassessments ($US570 million).

Even excluding those write-downs, BHP Billiton's underlying net profit crashed 81 per cent to $1.22 billion.

However, metals and mining analyst Peter O'Connor from Shaw and Partners said BHP Billiton's underlying result beat expectations of a number around $1.1 billion.

"It included contributions from their key four assets, of which three also beat the expectations of the market - that was from their petroleum unit, their copper unit and their coal unit - the only area that disappointed was in iron ore," he told ABC News Online.

"The benefit of a benefit of a better operating result came from the cost line, which is something they can control."

The Anglo-Australian mining giant declared a final dividend of 14 US cents per share, fully-franked, down 77 per cent from last year's final payout of 62 US cents.

Mr O'Connor said the size of that dividend cut and an increase in debt will be the market's two main concerns.

"Their dividend was below what people thought it would be, firstly, secondly, their debt went up, not flat to slightly down as I thought it could be," he said.

BHP Billiton shares closed up 0.5 per cent at $20.25 on the Australian market ahead of the results release and were up 1.5 per cent in early London trade around 6:00pm (AEST).