Scoot will acquire several SilkAir routes over the next two years, ahead of the latter's announced merger into Singapore Airlines (SIA).
Scoot, SIA's budget arm, will also transfer some of its services to existing destinations served by SIA and SilkAir.
The changes are expected to take place between next April and the second half of 2020, SIA said yesterday.
They are the result of a detailed review to identify which airlines in the SIA Group portfolio are best suited to meet evolving customer demand, the airline said.
Among the changes: SilkAir will transfer to Scoot flights to Luang Prabang and Vientiane in Laos; Coimbatore, Trivandrum and Visakhapatnam in India; and Changsha, Fuzhou, Kunming and Wuhan in China.
Scoot will also operate existing SilkAir services to Chiang Mai in Thailand, Kota Kinabalu in Malaysia and the Indonesian cities of Balikpapan, Lombok, Makassar, Manado, Semarang and Yogyakarta.
Apart from the transfers, there will also be several other net-work changes.
SilkAir will convert its Mandalay route to a seasonal service. Existing services will end next March and will resume next November, continuing until January 2020.
Meanwhile, Scoot will suspend services to Honolulu with effect from next June as a result of weak demand.
Customers with existing bookings on all affected routes will be provided the option to switch to the new Scoot, SIA or SilkAir flights where possible, or will be given refunds.
SIA chief executive Goh Choon Phong said: "We are now at the half-way mark in our three-year transformation programme, and today's announcement represents another significant development.
"The route review will strengthen the SIA Group for the long term, with the right vehicles in our portfolio of airlines deployed to the right markets," he said.
SIA announced in May that its regional wing SilkAir would undergo a significant investment programme to upgrade its cabin products ahead of its eventual merger into SIA.
The programme will see SilkAir's cabins fitted with new lie-flat seats in business class and the installation of seat-back in-flight entertainment systems in both business and economy classes.
The investments will ensure closer product and service consistency across the SIA Group's full-service network, the airline said then.
Scoot's fleet will meanwhile be expanded, with the transfer of 14 Boeing 737-800s from SilkAir, while SilkAir will continue growing its operations in the years ahead as it takes delivery of new Boeing 737 MAX 8 aircraft.