QANTAS has offered voluntary redundancies all 7,000 of its cabin crew in response to high oil and jet fuel prices.

"Qantas issued a voluntary redundancy registration of interest pack to all cabin crew members today," a Qantas spokesperson said.

Chief executive Alan Joyce says Qantas is facing its most serious challenge since the peak of the global financial crisis.

"We need to act decisively to respond to rising fuel costs and natural disasters, just like we did during the global financial crisis, to ensure the ongoing sustainability of our business," he said.

Qantas wants to reduce its planned capacity growth on domestic flights from 14 to eight per cent, and on international routes from ten to seven per cent.

Qantas will also suspend up to four Jetstar services from Australia to Japan, as well as Qantas flights between Perth and Tokyo, and put a smaller capacity aircraft on the Sydney-Tokyo route.

The airline is also cutting three daily New Zealand domestic flights to Christchurch and one Melbourne to Christchurch flight, the ABC reports.

The announcement came on the same day the airline announced its international unit carried 509,000 passengers in April 2011, up 7.4 per cent from April 2010.

Qantas last month announced it will lift the price of its European flights after the EU, under its emissions trading scheme, said it would force the airline to pay a tax on 15 per cent of its carbon emissions from its nearest port of departure.

Meanwhile, a recent US study placed Qantas fourth in the world for revenue raised by ancillary charges for items such as baggage.

Qantas earned about $1.5 billion in 2010 as a result of the charges, consultancy firm IdeaWorks found, placing it fourth below US airlines Delta, American and United.

The move towards voluntary redundancy for cabin crew is the latest in a series of industrial issues for the airline.

The Australian and International Pilots Association (AIPA) is currently considering industrial action over wages and conditions following a canvas of its 1700 members.

If the pilot's strike goes ahead, it will be the first of its kind in 45 years.