The communications regulator published a list of regulations yesterday designed to force Vodafone and O2 to provide access to their mobile networks.
The Commission for Communications Regulation (ComReg) wants to use its influence to persuade the two dominant mobile operators to offer deals to so-called "virtual mobile operators".
Virtual operators are firms that do not own a mobile network but that lease space on other firms' networks to offer consumers a mobile service.
Under ComReg's regulations, which are likely to be appealed by the mobile operators, it would have the power to intervene in negotiations between network operators and virtual operators.
The regulations will also force Vodafone and O2 to provide monthly reports on their commercial negotiations with virtual operators to allow ComReg to assess if it needs to intervene.
Following the publication of the regulator's decision yesterday, O2 and Vodafone will have to provide this monthly report to the regulator within 28 days after a meeting with a virtual operator .
In its decision notice, ComReg says that it would prefer commercial negotiations between firms to succeed and reflects on the objections of the mobile operators.
On the contentious issue of whether the third player, Meteor, is providing competition in the market, ComReg says that the national roaming deal agreed between O2 and Meteor has enabled the third mobile operator to compete more effectively in the market.
But it says there is no evidence that it is significantly altering the development of the market.
ComReg says that it will monitor Meteor's impact on the market at a retail and wholesale level. However, three of the four mobile phone firms in the Republic have appealed ComReg's earlier ruling that Vodafone and O2 are jointly dominant in the market.
If this appeal to the State's new electronic communications appeals panel succeeds, then ComReg's new regulations on "virtual operators" will not come into force.