SYDNEY, AAP – Woodside Petroleum has swung back to a half-year profit a day after agreeing to acquire BHP’s entire petroleum division in an all-stock deal.

Australia’s biggest oil and gas producer on Wednesday posted a first half profit of $US317 million ($A437 million) on the back of a rebound in oil and gas prices.

The company had posted a $US4.06 billion loss at the same time last year after hefty writedowns.

Revenue for the six months to June 30 lifted by 31 per cent to $US2.5 billion.

“Our revenue was buoyed by higher realised prices driven by the recovery in demand for LNG and oil,” Meg O’Neill, who was named permanent chief executive on Tuesday, said.

“Sales volumes increased by 6 per cent to 53.9 million barrels of oil equivalent for the half, as we increased trading activity in response to favourable market conditions,” she added.

The result follows the announcement on Tuesday that Woodside would acquire mining giant BHP’s entire petroleum division spanning Australia, the Americas and North Africa.

The deal will give BHP shareholders a 48 per cent stake in the expanded company.

The combination would increase Woodside’s cash flow and financial strength to fund near-term projects and new energy sources, Ms O’Neill said.

“The proven capabilities of both Woodside and BHP will deliver long-term value for shareholders through our geographically diverse and balanced portfolio of tier-one operating assets and low-cost and low-carbon growth opportunities,” she said.

Woodside has declared a first-half dividend of 30 US cents per share, up from 26 US cents at the same time last year.