Auckland Airport could contribute nearly a fifth of national gross domestic product and sustain more three quarters of a million jobs by 2031, according to a new study.

The Market Economics study, commissioned by Auckland Airport, said the airport was expected to grow faster than the regional and national economies during the next two decades.

The airport was projected to generate and facilitate 14-19 per cent of national GDP, and 528,000-756,000 jobs by 2031, up from 13 per cent and 319,000 jobs in 2006.

The projection of sustained jobs related to direct and indirect employment across the country associated with the flow of freight and passengers through the airport and were mainly tourism related.

The airport already played a significant role in regional and national economies, the study said.

The airport corridor - comprising the airport company itself, and related businesses on airport-owned, neighbouring land and access routes - generated or facilitated about $3 billion of annual gross domestic product, which was expected to grow to $5-6 billion by 2031.

The airport corridor would be a major focus of business activity and a catalyst for economic growth across the region, the study said.

The airport was expected to generate or facilitate up to $25 billion of regional GDP by 2031, up from $11 billion in 2006.

Auckland Airport chief executive Simon Moutter said the study reinforced the important role the airport played in helping to grow tourism and trade by improving the air services connections.

"The more successful we are at encouraging new and existing airlines to fly here more frequently, the greater the flow-on economic benefits for New Zealand," Moutter said.

"Each international visitor, for instance, generates around $2,500 for New Zealand tourism."

China Southern Airlines this month said it would start direct flights from Guangzhou in April, which Moutter said would inject an additional $75 million annually into the economy.

It was important the airport was seen as a key driver of the supercity's economic prosperity, he said.

"By commissioning this study, we hope to improve understanding about the strong growth potential of both Auckland Airport and the airport corridor."