BEIJING — China's airline industry association has thrown its support behind 13 Chinese carriers seeking compensation from Boeing Co. for groundings of the 737 Max 8.

The China Air Transport Association said in a statement Friday that the groundings and delayed deliveries of the planes were causing "serious damage" to the companies' businesses. It estimated their losses at $580 million should the planes remain grounded through the end of next month.

The group said it would "actively support and coordinate member companies to carry out their compensation work."

It was unclear if the push to penalize the American aircraft maker over losses resulting from the grounding of the aircraft was in any way linked to trade tensions between Beijing and Washington.

China was among the first governments to order 737 Max jets grounded in March after crashes in Ethiopia and Indonesia that killed 346 people.

The Chinese airlines, including major carriers Air China, China Eastern and China Southern, have 96 Max aircraft in their fleets, with more than 30 more due to be delivered this year.

Aviation officials from more 30 countries met Thursday with the FAA to hear the U.S. regulator's approach to reviewing changes that Boeing is making.

The company has not yet submitted a final, formal application for approval of its update to a flight-control system that has been implicated in the crashes. That submission will be followed by test flights to demonstrate the changes to FAA experts.

Acting FAA administrator Daniel Elwell declined to give a timetable for the agency's review, saying the agency won't allow the Max to return to the skies until it is convinced the plane is safe.

In a setback to FAA's prestige, other regulators around the world grounded the plane in March after the second crash without waiting for the FAA to do so. The FAA hopes that this time, other regulators — some of whom are doing their own separate reviews — will approve Boeing's changes at the same time or soon after FAA does.

"Our review of the Max design changes, the software upgrade, is already under way," said Nicolas Robinson, the head of civil aviation for Transport Canada, that country's counterpart to FAA.

Robinson said, however, that it's "difficult to put a time limit on that" because the length of the review will depend on how quickly Canada gets answers to questions it has about Boeing's work.

Robinson said that at Thursday's meeting some attendees put timelines on the review process but the consensus — and the view of FAA — was that "this is not about meeting a deadline, it's about getting safety done properly. It will be done when we feel comfortable."

Separately, United Airlines is canceling another month's worth of flights on 737 Max planes.

The U.S.-based carrier said Friday it has removed the Max from its schedule through Aug. 3 and will cancel about 2,400 flights in June and July as a result. It had previously canceled all Max flights through early July.

Southwest and American have already dropped the Max from their schedules into August.

United is using other planes to cover some flights that had been scheduled with its 14 Max jets. However, the airline said that because of the Max's grounding it will cancel about 1,120 flights in June and about 1,290 in July.

Contact John McDermott at 843-937-5572 or follow him on Twitter at @byjohnmcdermott

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