The process of reconnecting 55,000 Smart Telecom customers begun today.
So far around 100 customers have had a partial service reconnected and it is expected that it will take three days before all customers will have a partial service where they can make local and national calls only.
Eircom, which controls fixed-line telephone services disconnected its leased lines to Smart without warning Smart customers on Monday evening. A spoikesperson for Eircom said it was up to Smart to warn its customers about the disconnection.
Eircom said it told ComReg of its intention to end Smart Telecom's service a month ago and asked the regulator to prepare an emergency plan.
The company says Smart owes €4 million, with arrears totalling €1.7 million.
Last night, the telecoms operator ComReg and the two companies came to an agreement about reconnecting the 55,000 customers to a partial service.
An Eircom spokesperson said that as it is an interim service, the process of reconnection will take three days.
Smart has been in financial difficulty, with its biggest shareholder, Brendan Murtagh, providing up to €3 million a month to keep it afloat.
Last night, it appeared that a consortium led by Mr Murtagh had agreed to refinance the company, thereby drawing it back from the brink of liquidation.