Qantas staff are worried about their employment security with the airline, according to a report.

Concern arose after Qanta's bidder, Airline Partners Australia (APA), revised a key condition of its takeover plan last week, which calls for the airline to take on more debt.

APA plans to pay itself $4 billion from the first year of ownership which almost doubles current debt levels.

The revision was made when some institutional shareholders threatened to reject APA's $11 billion bid, reducing the minimum shareholder acceptance level to 70 percent from the 90 percent required to force the sale of all shares and delist the airline.

What's happened is, it has become clearer that the profit that the Airline Partners seeks as a result of their investment will simply create a greater debt for Qantas and, in the process, put pressure, of course, back on the jobs of working Australians, Australian Council of Trade Unions president Sharan Burrow told Fairfax newspapers.

Qantas unions sent a letter on Friday asking to meet and discuss details of the airline's plans and their impact on employees, according to Fairfax.

Qantas