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By Conor Humphries
DUBLIN, July 29 (Reuters) - Ryanair is worried that further delays in the return of Boeing's 737 MAX to service could leave it without any of the jets next summer, forcing it to cut its growth plans further.
Ryanair earlier this month cut the number of 737 MAX jets it plans to fly next summer from 58 to 30, halving its growth rate for the year from 10 million to 5 million passengers.
"I am concerned that the MAX return to service keeps slipping," O'Leary told a conference call with analysts.
While its current estimate is for the company to take 30 aircraft for summer 2020, that could fall to as few as 20, "which would significantly truncate our growth rate," O'Leary told analysts on a conference call.
"It could move to 10 and it could move to zero if Boeing don't get their shit together pretty quickly with the regulator," he added.
Boeing Chief Executive Dennis Muilenburg said on Wednesday he was confident the MAX would be back in service as early as October, though the U.S. Federal Aviation Administration said regulators do not have a timeline for vetting safety upgrades.
Boeing could not immediately be reached for comment on Monday.
Ryanair is facing a pinch point in that it only has the capacity to accept delivery of eight aircraft per month and cannot take any during its peak summer months.
The MAX-200 model it has ordered is also likely to take one to two months longer for regulators to approve, he said.
"It's very difficult to deal with the Boeing delays because they keep getting delayed further and further." The situation, he said, is "moving in the wrong direction".
O'Leary said he had been informed on Friday that Boeing had pushed back software amendments required for the return to service to October rather than September. (Reporting by Conor Humphries; Editing by Louise Heavens and Jan Harvey)