ESAT Telecom has been haemorrhaging staff since the company has been bought by British Telecom, the Irish Independent has learned.
In the past six week it has lost up to 90 workers including a team of senior directors.
Among them have been the Esat Telecom marketing director Tara O'Sullivan, head of activations Eoin Pearson, director of human resources Martin Walshe, sales directors Brendan Lundy and Todd Larson, general manager of data Mark McCloskey and Jarleth Burke their head of regulatory and legal counsel.
Esat Telecom was bought by the British phone company in January for £1.9bn and the staff at the Irish firm enjoyed significant payouts when their shares were bought by BT as part of the deal.
British Telecom also bought the 50pc of Dublin-based phone company Ocean, which it did not already own, from the ESB. Ocean is currently being merged with Esat.
Sources suggested that many of the staff left as they felt there would be significant job losses because both Esat and Ocean have sales and marketing departments and there would be an overlap.
Excluding Esat founder Denis O'Brien, the management, directors and staff owned shares worth $150m before they sold the stock to British Telecom.
An Esat spokesman said: ``Yes, a number of people have left of their own accord after contributing significantly to the growth of Esat however the numbers leaving are not significant.''
All of the workers who have left were in Esat Telecom, which is a subsidiary of the Esat Telecom Group employing a total of 2,300 workers.