PARIS, April 6 (Reuters) – European planemaker Airbus delivered between 140 and 142 aircraft in the first quarter, up almost 13% from the same period last year, industry sources said on Wednesday.

Airbus declined comment ahead of monthly orders and deliveries data due on Friday.

The figures imply March deliveries of some 62 jets, at least some of which came from long-term storage, the sources said.

Airbus is in the midst of planned production increases of single-aisle jets, but faces growing concern over manufacturing supply chains.

Jefferies analyst Chloe Lemarie this week estimated total quarterly deliveries of 139 aircraft but said “production challenges” and demand were under scrutiny.

According to an Airbus court filing connected to a legal dispute with Qatar Airways, as of March the planemaker was producing 50 narrowbodies a month, including 27 A321neos.

It plans to increase this to 61 a month by end-2022 of which 33 will be A321neos, the filing said, adding that the planemaker ultimately aims to raise production above 70 a month by 2025.

“This is clearly a challenging target, and the pressure on suppliers to keep pace is high,” it said.

Airbus has so far publicly committed to raising output to 65 a month by the summer of 2023, without giving interim steps.

It has said it is asking suppliers to be ready for output of 70 a month by the first quarter of 2024, if a decision to raise output again is taken, while exploring rates up to 75 by 2025. Read more