Insurance Ireland, which covers over 90% of the Irish motor vehicle insurance market, runs a data system called Insurance Link and sets conditions for accessing it.
The platform offers a non-life insurance claims data pool and a facility for its users to request certain data about such claims, enabling insurers to better assess risk and combat potential fraud.
The European Commission said preliminary findings showed that Insurance Ireland arbitrarily delayed or de facto denied the access of certain insurers and their agents to Insurance Link.
It said access since at least 2009 and until today was linked to membership in the association.
"We have concerns that certain insurers and their agents were put at a competitive disadvantage," European Competition Commissioner Margrethe Vestager said in a statement.
"This prevented competitive entry of new players and thus reduced Irish drivers' choice of motor insurance policies at competitive prices," she said.
The Commission said it had sent a so-called statement of objections to Insurance Ireland outlining charges of anti-competitive practices.
Insurance Ireland said it would respond to the charges in the coming weeks.
"We are confident that we can allay the European Commission's perceived concerns," the association said in a statement.
Companies found guilty of breaching EU antitrust rules face fines as much as 10% of their global turnover and orders to change their business practices.
(Reporting by Foo Yun Chee, additional reporting by Padraic Halpin in Dublin;Editing by Mark Potter and Louise Heavens)
By Foo Yun Chee
