Airbus is in talks with U.S.-based private equity firm Indigo Partners about a potential sale of its new A321XLR passenger jet, industry sources said on Thursday.

Airbus, which declined to comment, is trying to cement the launch of its longest-range single-aisle jet at the Paris Airshow next week.

Indigo Partners, which also declined comment, buys aircraft on behalf of four airlines in which it holds stakes, using its bulk purchasing power to squeeze lower prices from planemakers.

Led by airlines investor Bill Franke, Indigo Partners placed a record order for 430 narrow-body Airbus A320neo-family jets spread among four low-cost carriers in 2017.

Airbus hopes to persuade the veteran airlines promoter to invest in a longer-range version of the same aircraft family.

The European planemaker is widely expected to announce the launch of the roughly 4,500-mile A321XLR model at the showcase event in Paris on June 17-23. The model will enter service in late 2023 or early 2024.

It was not immediately clear to what extent a new Indigo Partners deal would involve conversions from existing models included in the big 2017 order.

American Airlines Group is also considering the A321XLR as one new aircraft option, an American source said, but noted that it was premature to discuss whether any potential order would be new or a conversion of existing Airbus orders.

Airbus is expected to insist that airlines wanting to reserve some of the early production slots reserved for the A321XLR must place new orders, though it is also likely to allow buyers to trade some existing purchases for the new jet.

Boeing had a similar mix of new orders and conversions when it announced the Boeing 737 MAX 10 in 2017.

Asked by shareholders on Wednesday about new aircraft purchases, American Chief Executive Doug Parker said "there's nothing that we haven't announced coming to us".