Dublin light rail operator Transdev, which is locked in a protracted pay dispute with Luas drivers, is seeking to win the right to run bus services under new Government reforms.
Under the Government's plans about 20 routes in the capital operated by Dublin Bus, as well as some run elsewhere around the country by Bus Éireann, will be put out to tender.
While the State transport companies can compete to continue to operate the services, the process which is now getting under way will also be open to private firms.
A spokeswoman for Transdev said it would be bidding to operate routes as part of the tendering process which will be carried out by the National Transport Authority.
Staff in Dublin Bus and Bus Éireann are strongly opposed to the reforms, which they fear could lead to the privatisation of bus services traditionally operated by the State sector.
The proposals led to a strike by workers in the companies in 2015.
Under a formula drawn up by the Labour Relations Commission last year, safeguards were put in place for workers in the State companies if the contracts for the routes went to private sector operators.
Private company
Former minister for transport
Paschal Donohoe
also insisted that no Dublin Bus or Bus Éireann employee would be forced to move to a private bus company even if the State firms lost the right to operate any route.
Some of the Dublin routes going out to tender include the 18 route (Palmerstown to Sandymount), 17 (Rialto to Blackrock), 33a (Swords to Balbriggan), 33b (Swords to Portrane) and 76 (Chapelizod to the Square in Tallaght).
Bus Éireann routes being tendered include the 120 Edenderry-Tullamore route, the 130 Naas-Athy route and a number of routes in Waterford.
Meanwhile on Saturday, new Minister for Transport Shane Ross again ruled out intervening in the Luas dispute which has led to services being halted on 11 days in recent months due to industrial action.
More strikes are planned for later this month and for June.