PARIS, May 31 (Reuters) - Airbus is facing new

pressure on its planned production ramp-up for passenger jets as

the world's largest planemaker struggles to overcome continued

parts and labour shortages, industry sources said on Thursday.

It was not immediately clear whether the slowdown would put

at risk overall delivery targets for 2024 since deliveries lag

output decisions by months, but the sources said assembly of

several dozen jets could be delayed in the second half.

Several airlines could see individual deliveries - already

running an average of 1.5 months behind schedule - further

delayed, the sources said, asking not to be identified.

A spokesperson for Airbus referred back to the group's last

quarterly results, in which it reiterated a 2024 delivery target

of 800 airplanes, and declined further comment.

Airbus shares were down around 2% in the wake of the Reuters

report, within a flat French blue-chip index.

By the end of April, Airbus had delivered 204 airplanes

since the beginning of the year.

Airbus plans to raise underlying production of aircraft by

about 50% to 75 narrowbody planes a month in 2026.

Sources have previously said it hopes that any delays can be

recovered in time to meet the medium-term goal, but the

available buffer for delays is shrinking.

The supply chain is responsible for up to 80% of the content

of Airbus jets and stretches as much as nine layers deep.

Details of Airbus' industrial process were disclosed in

legal filings during a dispute with Qatar Airways in 2022 and in

conversations with sources who spoke on condition of anonymity.

Each month Airbus holds an internal meeting to match

industrial production to demand several years ahead.

Parts are typically ordered 12-13 months ahead for standard

narrowbody aircraft like the in-demand A321neo single-aisle, or

longer for variants that require more customisation.

But lead times for some scarce parts like forgings have more

than doubled to as much as two years, the industry sources said.

Disruption to seat supplies remains an issue especially for

wide-body aircraft, leading to delays in handling customised

orders.

The rolling forecasts are translated into fixed production

plans for specific aircraft for the next three months and then

final adjustments are made on a monthly basis.

Suppliers said these monthly requests known as "call-offs,"

are being regularly deferred, which signals more delays in

putting aircraft onto the assembly lines later this year.

The mounting pressure comes as airline leaders prepare for a

high-profile annual summit in Dubai, with concerns about plane

shortages expected to be voiced publicly for a second year

running by the International Air Transport Association.

On a positive note, Airbus is increasingly confident of

winning delayed certification for its A321XLR passenger jet in

time for the Farnborough Airshow in July, industry sources said.

A spokesperson for the European Union Aviation Safety Agency

(EASA) said it expected to certify the aircraft by the summer

and declined to comment on a specific date.