On Friday, Reuters reported that Ryanair, Europe's largest budget airline, was in advanced talks to order at least 100 Boeing 737 MAX 8 jetliners, modified to include 11 extra seats, bringing total seating in the new plane up to 200.
One source told Reuters the order could be for as many as 150 of the jets. A deal for 100 jets would be worth about $10.4 billion, at the 737 MAX 8's list price of $104 million, but airlines usually negotiate steep discounts, particularly on large orders.
Ryanair's order, if confirmed, would mark another major win for Boeing's 737 MAX program, which has garnered 2,219 orders since its launch in 2011.
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A deal also would be the first MAX order by Ryanair, continuing Ryanair's reliance on an all-Boeing, single-aircraft fleet. The airline only flies the 737-800.
Boeing also would further widen its lead over Airbus in the order tally so far this year if the deal is confirmed. At the end of August, Boeing had 1,004 total orders, and Airbus had 1,001.
Boeing also leads Airbus in orders this year after adjusting for cancellations, with 941 net orders from Jan. 1 to Sept. 2, compared with 722 net orders between January and August for Airbus.
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Boeing's 737 MAX competes with Airbus' A320neo. Both jets are based on the companies' top selling single-aisle planes, fitted with next-generation engines that reduce fuel consumption significantly.
Boeing says the MAX family will burn 16 percent less fuel than current competitors. Airbus has said its A320neo will provide similar savings.
The promise of such fuel savings has spurred strong demand from airlines eager to cushion rising oil prices. The MAX family is powered with engines made by CFM International, a joint venture of General Electric and Safran SA.
The A320neo offers a choice of engines, made either by CFM or Pratt & Whitney, a unit of United Technologies.
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Ryanair's O'Leary has said he would put slightly less than 200 seats on board the modified 737 MAX jetliner that Ryanair is expected to purchase, known as the 737 MAX 8, to avoid staffing the plane with an extra flight attendant, since one is required for every 50 passengers.
Last year Ryanair placed a $15.6 billion order for 175 Boeing 737-800 jets, and O'Leary said in July he would maintain that order, even as he studied a higher-density MAX version.