Australian flag carrier Qantas could shrink by half within a year if unions pursue their rolling strike action to protest pay and restructuring plans, its chief executive was reported as warning.

The grim caution came a day after a fiery annual general meeting at which Qantas management came under fire for its plans to refocus the airline on Asia and a union boss said the series of strikes could go on until mid-2012.

"If action continues as the unions have promised, we will have no choice but to shrink the airline bit by bit," chief executive Alan Joyce told the Daily Telegraph newspaper on Saturday.

"If it goes for more than a year, we estimate we will have to shut down half of Qantas operations. That's 50 percent of Qantas, gone," he said explaining that parts of Qantas would begin to be shut down if the dispute continued.

Joyce told the embattled company's annual general meeting on Friday that months of strikes by baggage handlers, engineers and pilots were costing the company AU$15 million (US$ 15.6 million) per week.

The industrial action had already cost the company AU$68 million, he said, accusing the unions of "slowly crippling our business and trashing our brand".

"It goes without saying that this would have very grave consequences for jobs," Joyce told the Daily Telegraph, raising the spectre of about 17,000 jobs being put at risk if around half the airline withers.

Baggage handlers, engineers and pilots have been staging industrial action aimed at forcing Qantas to scrap its "pan-Asian" plans, which will see it launch two new airlines and axe 1,000 jobs.

The unions claim Qantas will employ cheaper foreign pilots to staff the new Asian airlines who have less experience and training and are therefore more risky. Some workers are demanding larger pay increases to combat inflation too.

But Qantas says the demands are unreasonable and could jeopardise the future of the 90-year-old airline by severely limiting management's room to manoeuvre in a fast-changing market.

The leaders of the states of New South Wales and Victoria have called on Prime Minister Julia Gillard to intervene in the increasingly acrimonious row to prevent damage to business and tourism.

Gillard has however indicated the issue would be best settled by the company and its staff.