(Bloomberg) -- British Airways is leaning toward ordering Boeing Co. 777X aircraft to replace its aging 747 jumbo jets, people familiar with the matter said.

A deal is set to be announced as early as Thursday, when the airline’s parent company reports earnings, said the people, who asked not to be identified as the talks are confidential. Board members at the carrier’s owner, IAG SA, met Wednesday to review competing offers from Boeing and Airbus SE, one of the people said.

The size of the potential order isn’t known, although British Airways is poised to retire all 34 of its four-engine jumbos by early 2024. The carrier has also been mulling an order of an earlier Boeing model, the 777-300ER, to fill the gap in its network as deliveries of the 777X ramp up following the new jet’s commercial debut next year, the people said.

The endorsement by one of the world’s premier airlines gives new lift to the 777X program ahead of the upgraded model’s factory roll-out and first flight this year. Analysts have questioned the size of the plane, which features the longest wings ever produced by Boeing and can seat upwards of 400 travelers, as sales sputter after an initial order flurry. IAG also considered adding to an existing British Airways order for Airbus A350-1000 jets.

Representatives of IAG, Boeing and Airbus declined to comment.

‘Jumbo Killer’

British Airways’ fleet plan is accelerating the sunset of the iconic, hump-backed Boeing 747, as one the jet’s largest operators turns to a newer behemoth that has been described as a “jumbo-killer.”

The larger of the two 777X models is Boeing’s most expensive plane, with a list price of $442.2 million. Discounts are customary on aircraft purchases.

The U.K airline has stuck with its 747s even as many rivals have swapped their jumbos for the Boeing 777 and 787 Dreamliner, and the Airbus A350. British Airways’ 747-400 models have an average age of 22.1 years, according to Planespotters.com.

Interest has waned in four-engine passenger jets as airlines turn to more economical models for long-range flying. Airbus in recent weeks decided to halt production of its double-decker A380 after Dubai-based Emirates scrapped a crucial order.

To contact the reporters on this story: Benjamin Katz in London at bkatz38@bloomberg.net;Julie Johnsson in Chicago at jjohnsson@bloomberg.net;Richard Clough in New York at rclough9@bloomberg.net

To contact the editors responsible for this story: Brendan Case at bcase4@bloomberg.net, Lena Lee

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