SIA said the decision was taken in light of the "long road to recovery for the global airline industry" and the "urgent need" for the group’s airlines to adapt to an uncertain future.
In line with global traffic estimates, SIA expects to operate at less than 50% capacity versus pre-Covid levels until the end of its 2020/21 financial year, and does not expect numbers to recover to pre-Covid levels before 2024.
Additionally, the group said it was particularly vulnerable as it does not have a domestic market, which is likely to recover before the international long-haul market.
"In order to remain viable in this uncertain landscape, the group’s airlines will operate a smaller fleet for a reduced network compared to their pre-Covid operations in the coming years," said the group in a statement on Thursday (10 September).
Across Singapore Airlines, SilkAir and Scoot, some 4,300 roles will be lost, falling to 2,400 after taking March recruitment freeze, natural attrition, and the take up of voluntary departure schemes into account.
Discussions are under way with the group’s Singapore-based unions, with whom the group pledged to work closely to finalise the arrangements as soon as possible for those affected and "minimise stress and anxiety" for its employees.
Chief executive Goh Choon Phon said: “When the battle against Covid-19 began early this year, none of us could have predicted its devastating impact on the global aviation industry.
"From the outset, our priorities were to ensure our survival and save as many jobs as possible. Given that the road to recovery will be long and fraught with uncertainty, we have to unfortunately implement involuntary staff reduction measures."
Choon Phon continued: "Having to let go of our valuable and dedicated people is the hardest and most agonising decision that I have had to make in my 30 years with SIA.
"This is not a reflection of the strengths and capabilities of those who will be affected but the result of an unprecedented global crisis that has engulfed the airline industry."
He added: “The next few weeks will be some of the toughest in the history of the SIA Group as some of our friends and colleagues leave the company.
"We will conduct this process in a fair and respectful manner and do our best to ensure that they receive all the necessary support during this very trying time.”