BRUSSELS, Aug 27 (Reuters) - Ryanair Group Chief

Executive Michael O'Leary on Tuesday said that Boeing's ( BA ) new

management "continue to disappoint" and that deliveries were

behind schedule.

The Irish airline, one of Boeing's ( BA ) largest customers, said

there was a risk it would take delivery of just 20-25 of the 737

MAX aircraft ahead of next summer, rather than the 29 scheduled.

"Things are continuing to slip slightly, it's been

disappointing," O'Leary told Reuters in an interview.

"We're working closely with Stephanie Pope and the new team

in Boeing ( BA ), but they continue to disappoint us," he said,

referring to the head of Boeing Commercial Airplanes, who was

appointed in March.

Boeing ( BA ) last month named aerospace industry veteran Kelly

Ortberg as its chief executive.

Boeing ( BA ) has pledged to grow output by the end of the year,

after wrestling with supply chain snags and operating a slower

assembly line since a Jan. 5 in-flight blowout of a door plug on

a 737 MAX 9 jet that heightened regulatory scrutiny.

O'Leary said Ryanair had received five aircraft in July

instead of the seven scheduled and that it looked like it would

get just five of 10 scheduled for August.

"Boeing ( BA ) have had significant production problems. We think

they're getting to the end of that," he said.

Ryanair said in July that Boeing ( BA ) had warned it some 737 MAX

deliveries due by next spring would be delayed until the peak

summer months of 2025 - a repeat of delays this year that forced

a cut in its summer traffic volumes.

Ryanair, Europe's largest by passenger numbers, already has

150 firm orders for the MAX 10, the largest jet in the 737

family, and options for 150 more, with the first deliveries due

in 2027.

O'Leary said the smaller MAX 7 was supposed to be certified

by the end of this year, but that looks like slipping into the

first half of 2025.

He said it was "impossible to know" if certification of the

MAX 10 would be on time in the first half of 2025. "It's a

day-by-day challenge with Boeing ( BA )."