New Zealand's national airline has posted a record profit thanks to surging tourism and lower fuel costs, but warns it expects increased competition from rival international carriers in the year ahead.

Air New Zealand on Friday announced an after-tax profit of 463 million New Zealand dollars ($339 million) for the year ending June, an increase of 42 percent over the previous year. Revenue was up 6.2 percent over the previous year to a record NZ$5.2 billion.

A record 3.3 million people visited New Zealand in the year ending July, up 11 percent from the previous year.

Air New Zealand Chief Executive Christopher Luxon said competition is increasing because tourism to the South Pacific nation remains strong and lower fuel costs make New Zealand a more viable destination for rivals.