New Zealand Refining's profit has increased by 7.5 per cent to $31 million for the first half of the year despite margins being buffeted by the high value of the New Zealand dollar.
Chief executive Ken Rivers said the business environment had been difficult but the refiner's margins had strengthened.
Margins are calculated in US dollars and although they had increased from around US$5.50 to US$6.56 a barrel the greenback has ranged from NZ74c to NZ89c, averaging 78c during the six months to June 30.
"The business environment has been difficult - the outlook for the next six months is continuing US dollar weakness," Rivers said.
The company had been able to strengthen its liquidity position substantially, reducing debt from $86 million at the beginning of the year to around $54 million at the end of June. Margins around the world were strong because of continuing high demand, said Rivers.