Air New Zealand premium economy fares have been slashed by close to half in a sale this weekend.

The premium economy fares start at $699 return to Rarotonga, Sydney, Melbourne or Brisbane from Auckland.

The two-day sale through Flight Centre also includes Los Angeles, San Francisco and Houston for $2589 return from Auckland, Wellington or Christchurch on selected dates in May and June.

By comparison, premium economy fares to Los Angeles next month - before the sale period - are available on the Air New Zealand website for more than $5000 and about $4600 in early July, just after the sale dates.

Premium economy to Sydney next month starts at around $1100 and more than $1000 in September - after the sale period ends for Australian flights.

Air New Zealand on Thursday announced some cost cutting as it faces a dip in demand which it will hope to stimulate with this weekend's sale and get more certainty about loads on planes.

Premium economy passengers on the airline get more space because there are fewer seats in a row, more legroom, better meals and a more generous luggage allowance.

Since it was introduced 25 years ago, most airlines have installed premium economy to meet growing demand.

Sue Matson, Flight Centre NZ general manager retail, said customer demand for travelling in premium economy cabins had grown exponentially in recent years.

Already this year Flight Centre has experienced almost 65 per cent growth in premium economy fares booked. Throughout 2018, demand grew by almost 30 per cent.

"With a rise in carriers flying to New Zealand offering more premium services at affordable and accessible rates, flying premium economy is no longer the unattainable 'bucket list' style of travel it once was."

She said once passengers got a taste for premium economy they seldom moved back in the plane.

More corporates were opting for premium economy rather than business class but strong demand for the very front of the plane was increasingly coming from leisure travellers prepared to splash out for lie-flat seats.

Discounted economy fares on Air New Zealand are also on sale this weekend; there are $349 fares from Auckland, Wellington and Christchurch to Sydney, Melbourne and Brisbane on selected dates between May and September.