The wide-ranging agreement - subject to regulatory approvals - comes months after a memorandum of understanding in June and includes SIA’s subsidiaries SilkAir and Scoot, as well as Firefly, the sister airline of MAS.
Under the deal, SIA and MAS plan to operate flights between Singapore and Malaysia under a joint business arrangement.
This will see the carriers - which split out from Malaysia-Singapore Airlines in 1972 - coordinate flight schedules, offer joint fare products, align corporate programmes, explore tie-ups between their frequent-flyer programmes and share revenue on such flights.
In addition, SIA and MAS also plan to work on joint marketing activities to boost long-haul tourism to Malaysia and Singapore, including the potential development of airpasses.
Such airpasses will enable customers travelling to Malaysia through the Kuala Lumpur and Singapore hubs more choices to visit other parts of the country such as Kuantan, Kuching and Kota Kinabalu on a single ticket, the airlines said.
“We are very pleased to take our partnership with Malaysia Airlines to a new level,” said SIA CEO Goh Choon Phong. “This will be a win-win for both our airline groups, and provide new benefits for our customers.”
The two airlines also agreed to expand their codeshare routes.
SIA and MAS currently codeshare on flights between Singapore and Kuala Lumpur, Kota Kinabalu, Kuching and Penang.
Under the agreement, SIA and SilkAir plan to codeshare on MAS flights to 16 destinations in Malaysia - Alor Setar, Bintulu, Johor Bahru, Kota Bahru, Kota Kinabalu, Kuala Lumpur, Kuala Terengganu, Kuantan, Kuching, Labuan, Langkawi, Miri, Penang, Sandakan, Sibu, Tawau
The deal will also allow MAS to progressively codeshare on flights between Singapore and Malaysia, Europe, South Africa, and other destinations.
The agreement “represents a significant expansion of the existing codeshare agreement and will provide Malaysia Airlines with more opportunities to expand connectivity to and from Malaysia,” said the two airlines.
“We are honoured to collaborate alongside SIA in providing our customers a more competitive product between Malaysia and Singapore and the opportunity to travel to more global destinations,” added MAS CEO Izham Ismail.
“This partnership is more than a conventional partnership and we believe in the mutual benefits for both airline groups and countries.”
The cooperation between the carriers comes amid financial trouble at MAS.
The airline has been trying to transform its operations and return to profitability, as it continues to recover from two disasters in 2014, when flight MH370 disappeared in what remains a mystery and when flight MH17 was shot down over eastern Ukraine.
MAS is strengthening its operations and internal management via cost-cutting and service improvements, as well as strengthening codesharing pacts and joint ventures with other airlines to stay competitive.
The airline this month announced a codeshare arrangement with British Airways for 14 destinations.
Malaysian Economic Affairs Minister Mohamed Azmin Ali was reported as saying last week that the government is considering four strategic investors to form a synergy for the long-term operation of MAS.