BT Ireland has secured a wholesale contract with Sky Ireland to support the TV and broadband provider's rollout of ultrafast broadband across the country.
The agreement is the largest single deal that BT Ireland has ever signed.
Under the terms of the deal, BT Ireland will provide Sky Ireland with a managed service to help bring its ultrafast broadband offering to the market, including rural homes to be covered by the National Broadband Plan.
BT has also retained an existing deal with Sky Ireland for a further four years, covering an entire range of managed services, broadband and fixed line products.
Shay Walsh, managing director of BT Ireland, said the deal is "great news" for the market in general, because competition brings choice.
"Consumers and businesses will have more providers to choose from for phone and broadband services," he added.
JD Buckley, Managing Director of Sky Ireland, said the deal with BT reflects Sky's "continued commitment to investment in infrastructure in Ireland".
"It will also allow us to bring fibre to currently underserved rural customers as part of the Government’s National Broadband Plan," Mr Buckley said.