Malaysian airline Firefly will suspend all flights to Singapore with effect from Dec 1, the day it was scheduled to transfer its operations from Changi to Seletar Airport.
In a notice on its website, the airline said it would resume services once the relevant authorities can sort out regulatory issues with regard to its move to Seletar.
Firefly, a full subsidiary of Malaysia Airlines, did not elaborate further on its decision to suspend flights, but The Straits Times understands that it is in discussion with its country's regulator, the Civil Aviation Authority of Malaysia.
A spokesman for Changi Airport Group (CAG), which runs Seletar Airport, told The Straits Times it has been working with Firefly since 2014 to prepare for the move.
"Singapore has made all preparations and approved all applications by Firefly to conduct scheduled turboprop operations at Seletar Airport from Dec 1, 2018."
The airline said in its notice: "Firefly confirms it has had to suspend flights into Singapore effective Dec 1, 2018, until the relevant authorities have cleared remaining matters in relation to the Singapore authority's plans to move turboprop operations from Changi ... to Seletar."
The plan was for Firefly to move to a new passenger terminal that opened on Monday for scheduled commercial flights, chartered business flights and private jets.
CAG, which announced its opening, said all turboprop operations at Changi would move to the new Seletar Airport terminal from Dec 1.
Seletar Airport will also handle all scheduled turboprop flights in Singapore from that day, CAG said.
Currently, only Firefly operates such turboprop flights to Changi. It offers 20 daily flights, to and from Subang, Ipoh and Kuantan.
In its notice, the airline said: "Firefly has not been provided any definitive timeline by the authorities for the delay. Upon final approval from the authorities, Firefly will then resume its flights into Singapore.
"In the meantime, arrangements are being made for all affected passengers. We apologise to passengers for the inconvenience caused."
It is believed that at least 12,000 people have confirmed bookings on Firefly flights from Dec 1.
A Firefly spokesman had told The Straits Times on Monday: "We will move to Seletar Airport for sure. As to when that will happen, we are still in the midst of settling some issues internally and with CAG."
Seletar Airport's 10,000 sq m new terminal is designed to handle up to 700,000 passengers a year.
It was built to provide more space for Singapore's private and business jet traffic to grow, and free up capacity at Changi for larger planes.
CAG noted that the old Seletar Airport terminal building had not undergone any major refurbishments in the past 40 years, and was due for an infrastructural upgrade. CAG has been in discussion with other airlines which have expressed interest to operate scheduled services to Seletar Airport, it added.