New Zealand's a2 Milk Co said on Wednesday its full-year profit nearly tripled in 2017 to hit its highest-ever level, fuelled by soaring demand for its infant formula products in China.

Net profit after tax rose to NZ$90.6 million ($83.4 million) for the year ended June, from NZ$30.4 million a year ago, beating an average estimate of NZ$81.5 million from three analysts polled by Thomson Reuters.

The a2 Milk Company has avoided the carnage felt at rival Bellamy's, seeing its sales jump by more than half. Credit:Louie Douvis

Revenue jumped 56 per cent to NZ$549.5 million, in line with the company's June guidance of NZ$545 million.

Infant formula sales accounted for almost a quarter of total revenue.