Staff at Bus Éireann face cuts in overtime, shift payments and expenses under a Labour Court recommendation.
In addition, clerical and executive staff will have to increase their working week from 36 hours to 39.
However, Labour Court Chairman Kevin Duffy said the changes should only constitute a temporary derogation from their existing terms and conditions and should be reviewed annually from 2014 until the company returns to a reasonable and sustainable level of profitability.
Bus Éireann is seeking a €9 million cut in payroll costs due to rising fuel costs, falling passenger numbers and a cut in its Government subvention.
It told the Labour Court the cuts were essential to ensure the viability of the company.
However unions; including SIPTU, the National Bus and Rail Union, the TSSA and craft unions; were resisting the cuts, which they argued would impact to an unacceptable extent on low-paid workers.
In the recommendation, Mr Duffy accepted that Bus Éireann was experiencing serious financial difficulties which have the potential to undermine its continued viability and put employment at risk.
He said he was satisfied that significant reductions in operating costs including payroll were essential to address those difficulties effectively.
However he noted that employees' terms and conditions were of long standing and not out of line with similar employments.
Mr Duffy said the Court could only recommend retrenchment of the type proposed by the company if it is plainly and unambiguously necessary in order to protect employment.
Under the proposals, self-certified sick leave will fall from four days a year to two, with staff also giving up three days of annual leave for the next three years.
Expense payments will be cut by 20%.
Overtime rates will fall from time and a half to time and a quarter for the first two hours overtime in any given day. Other overtime will remain at time and a half.
The bonus for rostered duty on Sundays will remain at double time. However, Sunday overtime falls from double time to time and a half.
Public holidays will be paid at time and a quarter plus statutory entitlements for a basic day.
All overtime on public holidays is reduced to a maximum of time and a half.
Shift payments are reduced from time and a sixth to time and a seventh, though if Bus Éireann’s financial situation improves significantly this should be reviewed next year with a view to restoring shift rates to current levels.