BRUSSELS, Aug 27 (Reuters) - Ryanair Group Chief

Executive Michael O'Leary on Tuesday said that relations with

Boeing's ( BA ) new management were "difficult" and that deliveries

continued to be 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,

O'Leary told Reuters in an interview.

"It's a day-by-day challenge with Boeing ( BA )," he said.