Boeing Co. won a jet order from Ryanair Holdings Plc valued at $15.1 billion, selling 170 of its 737-model planes as that aircraft is phased out in favor of the Max version, people familiar with the matter said.

The deal between Boeing and Dublin-based Ryanair may be announced as soon as next week, said one of the people, who asked not to be identified because the talks aren’t public.

The 737 is the world’s most widely flown jetliner, and the -800 version, the top-selling variant in Boeing’s current lineup, has a catalog price of $89.1 million on which airlines typically get a discount. Chicago-based Boeing is preparing to introduce the 737 Max with more efficient engines in 2017 to compete with Airbus SAS’s upgraded A320neo.

“We do not discuss publicly our conversations with our customers,” Marc Birtel, a Boeing spokesman, said Tuesday in an e-mail when asked about Ryanair. “We are in regular contact with them and all customers about their ongoing fleet requirements.”

Robin Kiely, a Ryanair spokesman, said the airline “does not comment upon, or engage in, rumor or speculation.”

The Irish Independent newspaper reported earlier Tuesday that Ryanair had placed a Boeing order for as many as 200 planes.