STOCKHOLM (Reuters) -Turkish Airlines could switch a recently announced order for Boeing 737 MAX jets to rival Airbus if talks with engine supplier CFM fail to make progress, the airline's Chair Ahmet Bolat said.

The warning comes after the Turkish flag carrier announced a tentative order with Boeing ( BA ) for 150 MAX planes coinciding with a meeting on September 25 between Turkish President Tayyip Erdogan and his U.S. counterpart Donald Trump, subject to a separate engine deal.

Transatlantic venture CFM International, co-owned by GE Aerospace and Safran, is the sole engine supplier for the Boeing 737 MAX and competes with RTX unit Pratt & Whitney for airline contracts on the Airbus A320neo family.

DISAGREEMENT ON COSTS

"If CFM comes to feasible economical terms then we are going to sign with Boeing ( BA )," Bolat told Reuters in Stockholm late on Wednesday. He added negotiations had made some progress, but disagreements on costs remained.

"If CFM continues its stance we'll change to Airbus. With Airbus I have choices," Bolat said, referring to the European planemaker's two engine suppliers.

CFM, the world's largest engine maker by the number of units sold, did not immediately respond to a request for comment. Boeing ( BA ) declined to comment.

The deal is part of a major fleet replacement and expansion to around 800 aircraft by 2033, after Turkish Airlines (THY) ordered more than 200 Airbus planes in 2023.

Industry sources said they still expected a deal to be reached, given the recent political attention to it and scarce supplies of competing Airbus jets. But the comments highlight recent tensions in the jet engine market.

A spate of engine shortages and growing maintenance delays have driven up engine parts prices and led to growing discord between suppliers and airlines across the aviation industry.

Airlines globally have voiced frustration over the disruption, including THY which is facing delays linked to Pratt & Whitney engines on its existing Airbus fleet. Engine makers say they need to be rewarded for huge financial risks.

THY OPEN TO PLACING ORDER ON DELAYED BOEING 777X

On a positive note for Boeing ( BA ), Bolat said THY was still considering placing orders for the troubled 777X mini-jumbo, despite recent reports of further setbacks to the long-delayed programme, and was closely monitoring its development.

Boeing's ( BA ) 777X, the world's largest twin-engined passenger plane, has faced repeated delays and is now expected to be ready in 2027, some seven years behind its original schedule.

Bolat said THY remained in regular contact with Boeing ( BA ), including discussions concerning the 777X, and was assessing which routes the aircraft would be best suited for.

"Once we have the right time, we're going to order some 777X," Bolat said, adding that THY was in no rush to order.