Dublin's Grand Canal Theatre is to be rebranded next year.
The flagship arts venue, which opened just 18 months ago, will be renamed the Bord Gais Energy Theatre as part of a new sponsorship package.
The energy provider will invest millions in advertising for the theatre as part of a six-year partnership.
Bord Gais chief executive officer John Mullins said the sponsorship will be a key pillar in the provider's marketing strategy.
"The expense of acquiring new customers is a significant cost to our business and to address this we must seek ways to encourage our customers to stay with us for longer by offering them compelling benefits that differentiate us from our competitors," he said.
All tickets, adverts and branding for the theatre will carry the Bord Gais name in a deal which the company said has a media value of 4.5 million euro.
Bord Gais also hopes to boost customer retention by rewarding loyal consumers with tickets to the theatre.
Mike Adamson, chief executive of Live Nation, the company behind Grand Canal Theatre, said he is confident the partnership will be innovative.
"The Grand Canal Theatre has only been in existence for 18 months and has already established itself as an important national asset with something to offer people from all walks of life," he said.