Ryanair isn’t keeping costs low when it comes to buying planes.
The budget airline is said to be close to finalising a potential $10bn (£6bn) deal with Boeing for around 100 of its new 737 Max jetliners.
Shares closed 0.75 per cent higher on Friday and a significant fleet announcement is due from both companies tomorrow.
Ryanair boss Michael O'Leary and Boeing chief executive Ray Conner will make an announcement at a meeting on Monday morning in New York, Boeing said.
Boeing recently said it was considering plans to increase seating capacity on the new planes, which would reduce airlines' costs per seat.
Ryanair’s existing fleet of Boeing 737-80s carries 189 passengers at a time, while the 737 Max could have 200 seats. Boeing is hoping to target low-cost carriers such as Ryanair with increased capacity as airlines seek to reduce costs.
A deal is expected to be agreed by as early as the middle of September Reuters reports, citing unnamed people familiar with the matter.
An additional 100 planes would increase the size of Ryanair’s fleet to 403 as part of ambitious plans to expand to nearly 500 by 2019 and boost passenger numbers to 120m a year by 2022.
Michael O’Leary’s airline last year signed a $15.6bn deal with boeing for 175 of the 737-800s.
There had previously been speculation that Ryanair might turn to Boeing's rival Airbus for future orders, choosing an Airbus' A350 over Boeing’s troubled Dreamliner for its planned transatlantic flights
Ryanair declined to comment and Boeing did not comment on further details of the announcement.
Update: This story was updated with Boeing's confirmation of a fleet announcement.