Staff at Dublin and Cork Airports operator DAA will be put on a four-day week and see their pay cut to 80pc of salary from April 24.
It is understood to be the first semi-state company or Government agency to seek such dramatic cost-cutting measures.
DAA employs more than 3,300 people in Ireland.
A memo to staff warns that, in some cases, people will suffer the temporary pay cut while still having to perform their full role, but in others people will not have enough work even for their reduced hours.
Staff were also warned a quick recovery from the Covid-19 crisis is no longer likely, and that air travel in particular will take time to recover.
The semi-state company said it would use the Government's Covid-19 temporary wage subsidy scheme to help pay staff but that it would cover only about 25pc of its total salary bill for the next 10 weeks.
In a memo to staff, DAA chief executive Dalton Philips said the wage subsidy scheme was "hugely complicated".
"It seems that its impact is not nearly as wide-ranging as it may have initially appeared," he said.
The collapse in air travel as a result of the Covid-19 means it is carrying costs of €10m a week with little income to pay for it.
The airport remains open and is designated an essential service to help repatriate Irish people from abroad and cargo flights, including medicine and health equipment.
But with its income mostly gone, management said they would move most staff to a four-day week from April 26 until June 20.
Pay will be reduced to 80pc of its current level, and will then be reviewed.
A very small number of highly skilled designated and essential frontline staff at Dublin Airport would continue to work full-time and would be paid their normal income, the company said.