Four people familiar with the negotiations told Reuters that an agreement could be signed as soon as next week, although the timing remains subject to the completion of discussions.
Neither Boeing, CFM International nor Turkish Airlines has publicly confirmed the development.
The negotiations have focused largely on the long-term economics of maintaining the aircraft’s engines rather than the MAX aircraft themselves. The 737 MAX is powered by CFM International’s LEAP-1B engine, produced by CFM, a joint venture between GE Aerospace and France’s Safran.
The dispute underscores a growing challenge for airlines and aircraft manufacturers: the cost of operating a new aircraft over several decades can be just as important as the price paid to acquire it.
Engine maintenance at centre of dispute
Turkish Airlines has sought a larger role in maintaining the LEAP-1B engines that would power its expanding MAX fleet, according to industry sources cited by Reuters.
The carrier reportedly wanted to establish what sources described as a CFM “premier” maintenance facility, giving it a position among the engine maker’s highest-tier maintenance partners.
Such an arrangement could provide Turkish Airlines with earlier access to new repair technologies and greater in-house capability to service its engines.
The negotiations have also involved the financial burden created by rising engine repair costs.
For airlines, engine maintenance has become an increasingly important part of fleet planning as repair prices, spare-parts costs and constraints on maintenance capacity put pressure on operating budgets.
Reuters reported that it remained unclear whether the parties had reached a final agreement on the proposed maintenance facility.
The issue is significant because the financial relationship between an airline and an engine manufacturer can extend for decades beyond the delivery of the aircraft. A seemingly attractive aircraft purchase can become substantially more expensive if maintenance, spare parts and engine repairs prove costlier than expected.
Turkish Airlines planning rapid expansion
The 150 MAX aircraft form part of a much larger agreement announced in September 2025.
At the time, Turkish Airlines agreed to acquire up to 75 Boeing 787 Dreamliners and committed to purchasing up to 150 additional 737 MAX jets.
Boeing said the combined commitments would eventually double Turkish Airlines’ Boeing fleet and support the carrier’s ambition to grow to about 800 aircraft by 2033.
The MAX order would also build on an aircraft family already familiar to the Turkish flag carrier.
Turkish Airlines introduced the 737 MAX 9 into its fleet in 2019, meaning a large follow-on purchase would expand an existing narrowbody operation rather than require the airline to introduce an entirely new aircraft type.
The carrier currently operates a fleet of more than 400 Boeing and Airbus aircraft and has embarked on an aggressive expansion programme centred on Istanbul as a major international aviation hub.
Its fleet strategy is not, however, limited to Boeing.
A senior Turkish Airlines finance executive recently said the airline was evaluating regional aircraft including the Embraer E2 and Airbus A220, as well as larger aircraft such as Boeing’s 777X and Airbus’ A350-1000.
Why the deal matters to Boeing
For Boeing, preserving the Turkish Airlines MAX commitment would protect one of its most significant recent narrowbody opportunities.
The original agreement was announced after a meeting between Turkish President Recep Tayyip Erdogan and then-US President Donald Trump, giving the aircraft purchase a wider diplomatic and commercial significance.
A collapse of the MAX portion of the agreement in favour of Airbus would therefore have represented a notable reversal of a high-profile Boeing deal.
The episode also illustrates how competition between Boeing and Airbus increasingly extends beyond aircraft prices.
Airlines are examining delivery schedules, financing, fuel efficiency and aircraft availability, but they are also scrutinising the costs and conditions associated with engines and maintenance.
Engine availability has become particularly important for airlines because repairs can take aircraft out of service for extended periods. Limited repair capacity and shortages of spare parts can consequently affect both operating costs and fleet utilisation.
For Turkish Airlines, which is planning to add hundreds of aircraft, the financial implications of those issues could extend well into the 2030s and beyond.
A test of Boeing’s MAX relationship with Turkish Airlines
A completed agreement would give Boeing a firm foothold in Turkish Airlines’ future narrowbody fleet and deepen an existing relationship with a carrier that already operates the MAX.
For CFM, resolving the dispute would secure a major long-term customer for its LEAP-1B engine while potentially expanding Turkish Airlines’ role in engine maintenance.
The immediate sticking point remains the maintenance arrangement.
If Boeing, Turkish Airlines and CFM can settle the outstanding issues over engine support, maintenance capabilities and associated costs, the long-delayed MAX commitment could finally move towards a firm order.
The outcome would demonstrate that, for major aircraft purchases, negotiations do not end with the aircraft catalogue price. The economics of engines, repairs, spare parts and maintenance support can determine whether a deal worth billions of dollars ultimately gets off the ground.