FARNBOROUGH, England (Reuters) - Airbus announced plane deals with Japan Airlines ( JPNRF ) and Virgin Atlantic at the Farnborough Airshow on Tuesday, while Qatar Airways held out the prospect of a "sizeable" order for wide-body jets around the end of this year or in early 2025.

Delegates are expecting limited deal-making at this year's showcase aviation industry event, with Europe's Airbus and U.S. rival Boeing ( BA ) sold out for several years of production and struggling to ramp up output.

Weak results from several airlines have also stoked concerns that the post-pandemic boom in travel is fading, though the jetmakers say this has not affected demand for planes so far.

Japan Airlines ( JPNRF ) finalised an order for 20 Airbus A350-900 and 11 A321neo jets, worth just over $3 billion in total, according to estimated delivery prices from Cirium Ascend.

The airline had said in March it would buy 21 wide-body A350s and 11 A321neo narrow-body jets, but it is only ordering 20 A350s now as it will receive one as a replacement for a jet destroyed in January in a collision with a Coast Guard aircraft.

Virgin Atlantic, meanwhile, ordered seven more Airbus A330-900s in a deal worth about $807 million, according to Cirium Ascend estimates.

The order builds on the airline's initial A330neo order in 2019 and will take its total A330neo fleet to 19. Reuters reported on Sunday that Virgin Atlantic was close to placing a top-up order for A330neos.

Also at the show, Qatar Airways CEO Badr al Meer said the airline would decide on a "sizeable" new order of wide-body jets around the end of this year or in the first quarter of 2025.

He added the company had also decided to extend the service life of its Airbus A380 jets and would carry out upgrades including new wifi.

Airlines are increasingly looking to run existing planes for longer as jetmakers struggle to deliver on their order backlogs.

Consultancy Bain said in a report last week that airlines faced their longest ever waits for engine maintenance amid the shortfall in new aircraft, adding to their costs.

British Airways CEO Sean O'Brien said at the air show that his airline was being "very vigilant" on new plane deliveries, but that at the moment "our planes are broadly coming in the timelines that we need them to come".

(Addition reporting by Allison Lampert, Tim Hepher, Joe Brock and Abhijith Ganapavaram; Editing by Mark Potter and Jo Mason)