Gigabit Fibre was founded last year with the aim of securing business under the government's National Broadband Plan, which pledged that 750,000 rural homes and businesses would have access to fast broadband services by 2020.
Gigabit CEO Peter Cook told the Irish Independent that while Gray has resigned as chair, she will continue to attend board meetings and act in an advisory capacity to the business.
She has been succeeded as chair by one of Gigabit's co-founders, Alan Harper, who was formerly the managing director of Vodafone UK.
