John Riordan is to head Calally Ltd, the company which is in the process of taking over Smart Telecom's business.
Mr Riordan is a former chief executive of Dutch-based cable company UPC, and was also chief executive of Princes Holdings, which was part-owner of Irish cable company Chorus.
Smart's acting chief Ciaran Casey is leaving the company, while director Brian Timmons also intends to go once the acquisition by Calally is completed. This is expected in the next couple of months.
The Calally deal was approved by shareholders at an EGM last October. Calally is controlled by businessman Brendan Murtagh.