Earnings before tax were down 12% to $216 million for the six months to December, while after-tax profit was down 6% to $133 million.
However, its record normalised earnings - those not recognising fuel hedge contracts losses or gains - were up 20% to $216 million.
Chairman Tony Carter said the result again demonstrated that Air New Zealand continued to be one of the few airlines in the world able to generate sustainable profits.
''The result was driven by strong revenue growth, underpinned by increased capacity and improved yields across the network,'' he said in a statement.
Operating cashflow was up 26% to $378 million on a year ago.
The dividend was increased 44% from a year ago to 6.5c per share. Air New Zealand's shares were up 3.3% at $2.66 following the announcement.
Craigs Investment Partners broker Peter McIntyre described Air New Zealand's result as ''solid'', saying the increased dividend highlights the board's confidence in second-half trading due to lower fuel prices and continued sales momentum.
Revenues were up 3%, year-on-year at $2.4 billion, passenger revenue increased to 3.2% at $1.93 billion, cargo revenue gained 5% but other revenues were down 2% and contract services were up 5%, he said.
''While the first half was a solid result, our key focus is on the impact of the significant decline in oil prices on Air New Zealand's earnings from January 1, given its hedging meant it did not benefit much over the first half,'' Mr McIntyre said.
In November, Air New Zealand stated that second-half earnings would see a significant additional improvement due to lower oil prices, which at that stage had fallen by 23%.
But since then, they declined a further 25%, Mr McIntyre said.
Mr Carter said the company stated in November that, should the then current level of jet fuel price persist, there would be a significant additional improvement in earnings in the second half of the financial year.
''Fuel prices are lower than in November and the sales momentum has been maintained, further strengthening the company's outlook for the current year and beyond,'' Mr Carter said.
Forsyth Barr broker Andrew Rooney described the airline's first-half result as ''strong'', driven by yield improvement, higher passenger numbers, some early fuel price benefit and stable unit costs - not including fuel.
''While the first-half result was short of our expectations, the potential fuel price benefit in second-half 2015 and full-year 2016 has been quantified by management. That could lead to some further material upgrades in market expectations for near-term earnings,'' Mr Rooney said.
He said there were some fuel benefits in the first half, where the average US dollar fuel cost, excluding the timing of hedge contracts was 4% down on a year ago, meaning overall fuel costs benefitted the normalised profit before tax by more than $22 million.
Mr Rooney noted Air New Zealand had outlined the potential fuel price benefit in second-half 2015 and 2016, should current spot rates persist.
He described Air New Zealand as having a ''favourable'' US dollar forward hedging position; being 94% hedged at US84.52 for second-half 2015 against the US dollar and 80% hedged at US81.75 for 2016.
