WELLINGTON - New Zealand's national carrier Air New Zealand will increase passenger capacity on routes to China by more than a fifth for the northern winter season to meet growing demand.

Flight capacity to Hong Kong, Beijing and Shanghai would rise by 21.6 percent from November this year to March next year with more frequent flights, the company said in a statement.

Capacity on the Auckland-Beijing route would rise 38.6 percent with the addition of a third year-round Boeing 777-200 service from early December.

The airline's Auckland-Shanghai route would see a capacity increase of 22.7 percent, with the addition of a fourth Boeing 777- 200 service operating from December to March.

"In addition, following strong demand for the overnight service from Auckland to Hong Kong, this route is up by 15.6 percent with a Boeing 777-200 operating daily services from November to mid- December, increasing to nine services per week from mid-December," said Air New Zealand deputy chief executive Norm Thompson.

Air New Zealand would also continue with plans to introduce a Boeing 747-400 on its Japan routes from December to February.

"We will be increasing our Auckland-Tokyo capacity by 16 percent, with the up-gauge of the daily service from a Boeing 777-200 to a Boeing 747-400 aircraft, reflecting our confidence in the return of tourists to New Zealand from this important market," said Thompson.

Auckland-Osaka capacity would rise by 7.7 percent following a reduction earlier in the year as a result of the Japan earthquake and subsequent tsunami. The planned frequency would return to the levels of the last northern winter with a Boeing 767-300 operating all services.

On North American routes, all Auckland-San Francisco services would be serviced by Boeing 747-400 aircraft, increasing capacity by 4.1 percent, while Auckland-Vancouver capacity would rise by 10. 1 percent.