Some 300 staff had been employed at the Broadmeadow Place site, which will close by the end of October.
A spokesperson for the telecommunications giant said: “Earlier this year, we announced a review of our contact centre in Enniskillen as part of our ambitious workplace transformation programme modernising and consolidating the number of offices we have.
“We recently closed our voluntary paid leavers offer for colleagues and over 80% of colleagues have taken the opportunity to take this up.
“We have now made the difficult decision to propose closing the site to the small number of remaining desk-based colleagues on 31st October and have entered into consultation with colleagues and trade union partners.
“We will continue to support all impacted colleagues throughout this process. These proposals will have no impact for customers. BT Group continues to make significant investments in the rollout of full fibre broadband and 5G mobile connectivity across Northern Ireland.”
Economy Minister Deirdre Hargey said the announcement on Tuesday “is extremely disappointing”.
“As a major employer in the region for over three decades, this decision is devastating for the workers and their families, and also for the wider community,” she added.
“In line with his commitment to regional balance Conor Murphy met with both CWU representatives and BT to retain these skilled jobs.
“He also supported Invest NI’s concerted efforts to work with BT to find an alternative site within Enniskillen so these jobs could be retained. I have asked Invest NI to ensure every step possible is taken to support the staff impacted.”
Deborah Erskine MLA agreed that that decision “is a major blow” to the local community and those directly affected.
“When the news first emerged in February, staff were told that the site was not likely to be a long-term location for a customer care centre, but that no final decision had been made,” the DUP representative explained.
“There has been a significant campaign since that time in an attempt to retain jobs in Enniskillen if possible.
“I am currently engaging with the chief executive of Invest NI and I am awaiting a meeting in relation to Enniskillen with the Economy Minister. The consequences for the local economy in Enniskillen as a result of such a decision to close the BT/EE site are far reaching.
“Regional balance in our economy is very important and particularly for areas in the west like Enniskillen which are further away from some of the main population centres and so opportunities are more difficult to access.
“Whilst those staff who have not signed up to the voluntary paid leaver scheme have been given the option of moving to another location, this is not likely to be feasible for many people.
“The company has previously been warned about the reputational damage they could suffer as a result of how this has been handled, so it is incumbent upon them to ensure that the terms of redundancies put in place treat staff fairly.”
The Fermanagh and South Tyrone branch of the Ulster Unionist Party said its colleagues have been pushing for a solution to the long term future of the Enniskillen site in both council and Assembly Chambers.
“Our MLA Tom Elliott had been lobbying the then Economy Minister Conor Murphy to step up and provide support to the Enniskillen site,” a spokesperson stated.
“This decision follows what we suggest was a deliberate ambiguous exercise that BT/EE carried out with the workers, elected representatives and department officials that was deeply frustrating about the future of Enniskillen.”