Meteor has asked the Commission for Communications Regulation (ComReg) to regulate Vodafone more strictly in the market for international roaming calls.
The State's third mobile firm has also begun talks to join one of two new pan-European alliances of mobile firms in an attempt to compete with the mobile giant.
Details of Meteor's strategy on international roaming, the term given to using a mobile phone abroad on a new network, are contained in a paper to ComReg.
The paper, which has been seen by The Irish Times, warns ComReg that Vodafone may use its dominance in European markets to undermine competition to the detriment of consumers.
Meteor is concerned that Vodafone will offer its sister firms in Europe preferential roaming rates that Meteor will not be able to compete with. It is also concerned that Vodafone is using technologies that prevent its overseas customers from roaming on Meteor's network when they arrive in the Republic.
"We are concerned that Vodafone appears to be developing handsets which do not allow the selection of any other networks whilst roaming other than a Vodafone group network," says the paper submitted to ComReg.
Meteor believes these types of systems limit customer choice as some of their roaming tariffs are cheaper than Vodafone's rates.
Vodafone Ireland confirmed yesterday that it had already introduced a system called "SIM-assisted roaming", which automatically moves its subscribers to a Vodafone group network.
But a Vodafone spokeswoman said the firm did not prevent its subscribers from roaming on Meteor's network when they selected manual on their mobile.
International roaming is becoming an increasingly important market for mobile firms and typically accounts for up to 15 per cent of a firm's revenues. Small mobile groups in Europe, such as Western Wireless International - which owns Meteor and a few other networks - is fearful that Vodafone's scale will undermine its ability to compete abroad.
Vodafone is the world's biggest mobile firm with 26 global subsidiaries and a further 10 franchise networks that have adopted the Vodafone brand.
Meteor's paper also discloses that it is in talks about entering a pan-European alliance of mobile operators to help it compete in the roaming market.
Last month, four of Europe's biggest mobile operators - Telefónica, T-Mobile, Telecom Italia Mobile and Orange - announced they would set up a pan-European partnership, FreeMove. The partnership will enable the firm's subscribers to check voicemails and access other services when abroad.
Britain's mmO2 and Spain's Amena joined a separate alliance called Starmap earlier this year.
So far Meteor's talks have not lead to an agreement to enter either of the two big alliances.
