New Zealand's national airline has posted a 24 percent jump in annual profit as it benefits from lower fuel costs and continues to expand in Asia and North America.

Air New Zealand announced Wednesday its profit after tax was 327 million New Zealand dollars (US$212 million) for the year ended in June. Revenue was up 6 percent to NZ$4.9 billion.

The company says domestic passenger numbers were up 3.4 percent and long-haul international numbers up 9.3 percent. The company says it plans to add new routes to Houston and Buenos Aires over the coming year as it expands its international capacity by 15 percent.

The airline's growth contributed to its net debt more than doubling to NZ$836 million.

The carrier is majority owned by the New Zealand government.