Z widened its gross margin on fuels 8 percent to $225 million in the half, by trimming out marginal business, while its non-fuels margin increased 7 percent to $31 million and its refining margin more than doubled to $24 million, earned through its shareholding in the country's only oil refinery, which reflected a weaker kiwi dollar and strong regional conditions supporting refineries.
The company reported a trebling in net profit to $67 million, bouncing back from a year earlier when it was dragged down by falling prices for oil and refined fuels.
The board declared an interim dividend of 8.5 cents per share, payable on Dec. 2 with a Nov. 20 record date.
The shares last traded at $6.75 and have gained 45 percent this year.
Z is seeking regulatory approval to buy Chevron's Caltex and Challenge! brands, which would give it 49 percent of the nation's retail market. In September, it raised its estimated savings from the merger to between $25 million and $30 million from an earlier range of $15 million to $25 million.
The company affirmed guidance for annual earnings to be within $245 million and $265 million, which included a one-off $24 million charge from additional Customs duties and penalties and the timing of the Chevron cut-over date.
Read the full Z Energy release here: