American Airlines says it is delaying the expected return date for its Boeing 737 Max jets.

The airline said Sunday that while it "remains confident" that coming software updates and training will mean recertification of the aircraft this year, it is extending cancellations for Max flights through Dec. 3.

The airline says this means about 140 flights per day will be canceled through Dec. 3. Not all flights scheduled on the Max will be canceled, though. The airline says it will use other aircraft for some of the flights. But some flights not scheduled on the Max jets may also be canceled.

United Airlines had also delayed the Max return date through Dec. 19.

RELATED: United removes Boeing Max from schedule until mid-December

Max jets have been grounded since March after two accidents that killed a total of 346 people. 

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