Eircom is set to sell its masts division to Threefold Project Management, a Sandyford-based company which was involved in the construction of 3's mobile phone network.
Threefold is believed to have offered more than €160 million for the business and the two sides are expected to sign contracts shortly.
Threefold was one of three groups shortlisted by Babcock & Brown, Eircom's Australian owners, in the sales process.
It topped offers made by Seán Melly's Powerscourt Investments, and Arqiva, a UK-based mobile communications group owned by a consortium led by Australian investment company Macquarie.
Eircom declined to comment on the sale.
Threefold employs more than 100 people and provides managed services in network infrastructure. Its customers include Eircom, NTL, 02 and Meteor.
The company was founded in 2002 by Tony Killarney, Tom Scanlon and Niall Savage. Mr Killarney also heads Maynooth-based Killarney Communications, a family-owned business involved in the design and building of telecoms and power transmission infrastructure.
Latest accounts for Killarney Communications show that it earned after-tax profits of €2.4 million on turnover of €34.6 million in 2005. The company has a 55 per cent stake in Threefold.
Eircom is believed to have attached a number of clauses to the sale of the masts. These include it being afforded "super preferred customer status", according to sources involved in the sale process.
The masts generate about €10 million in revenues annually, with Eircom the biggest customer, followed by mobile operator Vodafone.
Eircom was also thought to be seeking a clause giving it up to a 25 per cent share of any property development which might accrue from land around the masts.
