The transport regulator has confirmed that 10% of public bus routes will be transferred to private operators.
The National Transport Authority said that it will seek private operators to run 23 of the routes currently serviced by Dublin Bus.
It will also look for private operators to run bus services within Waterford city, and some commuter services around west Dublin.
Bus Éireann said it is concerned about the quality of services that could be provided on those routes, and that it will submit a tender to keep running them itself.