The alerts by Qantas and Air France-KLM come as concerns grow over the hit to the global economy.Read more
Air France KLM
Air France is buying 60 Airbus A220-300 aircraft, with an additional 30 purchase options and 30 acquisition rights.
The first aircraft should be delivered in September 2021.
"These decisions support the Air France-KLM Group's fleet competitiveness strategy," said Benjamin Smith, chief executive, of Air France KLM.
Air France KLM has reported a rise in its March passenger numbers compared with the previous year.
The airline said it carried 8.3 million passengers in March, up 3.4% from a year earlier.
However, Air France KLM's March passenger load factor dropped by 0.3 percentage points to 87.6%.
France is still upset with the Dutch government, which decided to suddenly buy a 14% stake in AirFrance-KLM on Tuesday.
The Netherlands government said it chose to buy the stake in order to "protect Dutch interests".
The Dutch now own a 14% stake in AirFrance-KLM, while France owns a 14.3% stake, which makes them almost equal.
"Between two states, which are friendly and close founding members of the European Union, such behaviour is unacceptable," French finance minister Bruno Le Maire told Public Senat television. "It's not reasonable to remain in this situation, which benefits nobody."
There had been concerns in early February that KLM boss Pieter Elbers would not be reappointed as chief executive of the Franco-Dutch airline holding company's division in the Netherlands.
In response, the Dutch government gave him its official backing, and KLM staff threatened to go on strike.
The Dutch government has acquired a stake a 12.7% stake in the Air France-KLM holding group and aims to raise that to equal France's 14.3%, according to media reports.
The Netherland's move is aimed at increasing its influence in the carrier and protecting the country's economic interests, reports said.