Virgin Media Ireland and Vodafone Ireland have agreed a wholesale network access deal.
The agreement will see Vodafone customers being given access to fixed-line broadband services using Virgin Media's fibre broadband network.
The Virgin Media network passes 1 million premises across Ireland with broadband speeds of 1Gbps (gigabits per second).
Virgin Media Ireland said it is the first time it has provided network access opportunities to other operators.
"Our entry into the wholesale market will support more competition while improving service delivery for consumers, businesses and communities across Ireland," said Tony Hanway, Chief Executive of Virgin Media Ireland.
Vodafone said the new partnership was a demonstration of its continued focus on its network investment strategy.
"Our new broadband partnership with Virgin Media means Vodafone customers will be able to avail of their Fibre to the Premise network, as they continue to upgrade to fibre around the country," said Amanda Nelson, CEO of Vodafone Ireland.