U.S. planemaker Boeing faces a December deadline to win approval for the 737 MAX 10, otherwise it must meet new cockpit alerting requirements under a 2020 law, unless waived by Congress. Last month it said it was working with regulators on the certification.

"I think Boeing accepts that it won't get certified by year end, but I suspect that Congress will approve an extension to that certification process out into early 2023," said Ryanair Group Chief Executive Michael O'Leary, who is negotiating with Boeing on a possible MAX 10 order.

(Reporting by Muvija M; Writing by Conor Humphries; Editing by David Goodman)