IranAir has abandoned plans to take early delivery of a Boeing 777-300ER jetliner because the passenger plane is no longer available, the head of the Islamic Republic's national flag carrier was quoted as saying by Iranian media.

Iran had been expected to receive the first of 80 aircraft ordered from the U.S. planemaker in April or May 2018, but Iranian media and industry sources said this month it might get the first Boeing jet a year earlier than expected under a proposal to swap deliveries with Turkish Airlines.

"Boeing had proposed to hand over a 777-300ER by summer after Turkish Airlines withdrew its order for it. We welcomed it ... However, when we were almost certain that we wanted the plane, it was no longer available," Chairman Farhad Parvaresh was quoted by Iran's English language Press TV as saying.

Industry sources had said Boeing was in negotiations to release at least one 777-300ER originally built for Turkish Airlines, which is deferring deliveries due to weaker traffic following last year's failed coup attempt in Turkey.

"We have currently stopped our negotiations in absence of the plane," Parvaresh was quoted as saying.

Boeing said it does not comment on specific deliveries.

"Boeing and Iran Air continue to work on implementing the sales contract for commercial passenger airplanes signed in December 2016, at which time we announced first deliveries are scheduled to start in 2018," a spokesman said.

"We continue to follow the lead of the U.S. government on all our dealings with approved Iranian airlines."

Since last year, when most sanctions imposed on Iran were lifted under a 2015 nuclear deal with six major powers, Tehran has joined a long waiting list for new airplanes and the swap would have allowed it to speed up its fleet renewal.

IranAir has also ordered 100 aircraft from Europe's Airbus under a deal to lift most sanctions in return for curbs on Iran's nuclear program, and has taken three deliveries.

Iran's return to the aviation market after decades of sanctions is a boon to planemakers trying to dispose of some new planes discarded by airlines facing economic difficulties.

But Western banks continue to shy away from financing deals between IranAir and Western companies, fearing U.S. banking sanctions that remain in force or a new chill in relations between Tehran and the West under U.S. President Donald Trump.