About half of the more than 400 staff employed by Mainzeal Property and Construction have been made redundant.
The country's third largest construction company went into receivership last Wednesday.
One of the receivers, Colin McCloy of PWC, says that with the suspension of work on Mainzeal sites around the country, they've found it necessary to review the staffing level and urgently reduce cash operating costs.
Mr McCloy says those made redundant are a mix of tradespeople and head-office staff.
He can't confirm whether they will receive a payout.
"Redundancy forms part of the preferential claim in a receivership," Mr McCloy says. "To the extent we can pay that out, we'll be paying on the assets we'll be recovering in the receivership, so I can't actually answer that question as of today."
The receivers issued affected employees with letters on Friday, but only made the news public on Monday afternoon.
Mr McCloy says the receivers are in talks with about half a dozen parties interested in buying the business and assets.
The future of the remaining staff is still up in the air.