Gulf Air appears to be the customer which cancelled an order for eight Boeing 787 aircraft last month.
The airline ordered 16 of the twinjets in January 2008 and supplemented them with a further eight in April 2009.
But Boeing's latest backlog figures show that the 2008 order has been halved to eight of the type, slashing the Bahraini flag-carrier's 787 total from 24 to 16.
Boeing disclosed in June that eight 787s had been removed from its order books, taking total 787 cancellations this year to 20.
Gulf Air could not immediately be reached to confirm the cancellation or to comment.
But the Middle Eastern carrier has been restructuring its fleet in favour of smaller-capacity aircraft, and during the Paris air show selected International Aero Engines powerplants for a batch of six Airbus A320-family twinjets, to be delivered next year.