Qantas has said a proposed merger with British Airways is not guaranteed and could be affected by BA's merger talks with Spain's Iberia.
Qantas chief executive Alan Joyce, who took on the position last month, said the Australian airline was still in negotiations with BA to create a global carrier.
But he said there were significant issues to resolve, against the backdrop of the financial crisis which is threatening a global recession and plummeting passenger numbers.
'We will only proceed with the transaction if we are assured that it will maximise value for Qantas shareholders,' he said.
Qantas and British Airways announced last week they were exploring a merger. But BA is already in parallel merger talks with Iberia, and Mr Joyce said it would be impossible for BA to tie up with both airlines.
Mr Joyce, who met BA chief Willie Walsh in Hong Kong over the weekend, said another potential problem was BA's pension fund, which reportedly has liabilities of around £1.7 billion.
