The changes to the Qantas Sales Act will lift the 49 per cent foreign ownership limit, as well as alter the restrictions on foreign airlines holding more than a 35 per cent stake and 25 per cent for any single foreign shareholder.
The airline, which is set to unveil a six-month loss on Thursday, has argued the laws distort the market and inhibit its ability to grow.
"We have indicated an interest in being prepared to seek to legislate to take away the legislative and government-imposed disadvantages that Qantas faces on the domestic market," Mr Truss told reporters in Canberra on Tuesday.
"We are working on legislation to achieve that.
"The government is philosophically attracted to levelling the playing field."
The laws also require the airline to keep most of its maintenance, catering, flight operations and training facilities for its international services in Australia.
Labor, Greens vow to block legislation
Labor and the Greens have vowed to block the legislation in the Senate.
Deputy Greens leader Adam Bandt says his party won't support a government debt guarantee for Qantas that's linked to job cuts.
"If the government is required to bring legislation to give effect to the debt guarantee before parliament -- which we have some initial advice that they will be required to do -- the Greens won't be waving it through without looking seriously at how we can protect local jobs.
"The Greens will look at the legislation and will explore amending it to ensure that government support comes with strings attached, and in particular that we retain a proper national carrier and that jobs stay onshore."
End the speculation on Qantas jobs: Union
The Transport Workers Union says Qantas needs to put an end to the speculation over its future after the company refused to comment on reports it will axe 5,000 jobs and sell its Melbourne Airport lease.
National secretary of the Transport Workers Union, Tony Sheldon, says Qantas needs to put an end to the speculation over its future.
"We've seen yet another day where Qantas has spread more rumours right across all the media outlets saying about what is or isn't going to be happening at Qantas. Quite clearly the company has made some very poor strategic decisions about its investment in Asia with its Jetstar operations."
Qantas 'not in a position to comment on speculation'
A report from News Corp Australia says the airline is planning to axe up to 5,000 workers, well above the 2,000 jobs losses previously expected, with 1,500 of those jobs expected to come from the company's executive and support divisions.
It also claimed Qantas was looking to sell its lease on Melbourne Airport and would announce the sale of its Brisbane Airport lease this week.
Qantas says it won't comment on the reports.
"There is fresh speculation about what things we will or won't announce on Thursday as part of our half year results," the airline said in a statement on Tuesday.
"We are not in a position to comment on that speculation."
But the airline acknowledged it would be making some "tough decisions" as part of its cost-cutting program.
"We have said that we will be making some tough decisions in order to achieve $2 billion in cost savings over the next three years, which is a consequence of an unprecedented set of market conditions now facing Qantas," it said.
Qantas has been lobbying the federal government for assistance, most likely in the form of a debt guarantee, though possibly also through the lifting of foreign ownership restrictions on the airline.
