Staff been given 48 hours to return any Fiji Airways property and to collect personal belongings from the office.
The letter said people who had been released could reapply for roles when the situation allowed.
All 79 expatriate pilots with the airline have had their contracts terminated as part of the moves.
Fiji Airways said eight expatriate executives had also been laid off.
The airline had six local executives who have retained their jobs and now constitute the majority of the leadership team.
The staff being let go will be paid a minimum notice period of one month, plus any accumulated leave and other entitlements.
A 20 per cent permanent salary reduction would also be implemented for all employees from June 1.
In the short term, staff are only being asked to work between two and five days a week.
Fiji Airways managing director and chief executive Andre Viljoen said the adjustments were necessary and unavoidable as the Covid-19 crisis continued to cause the further suspension of international services.
He said the company was also negotiating with its lenders and aircraft lessors for loan and lease payment deferrals, and arranging debt finance from a number of financial institutions.
Viljoen said the move was a very difficult one and had only been made after exhausting all other options.
