Mobile operator O2 Ireland had just under 1.6 million customers at the end of March, up 4% on the same period a year earlier.
Average revenue per user (ARPU) - the money it makes from each customer - was €552, compared with €544 in the same period a year earlier.
The first quarter of this year was O2's first reporting period since the company's takeover by Spain's Telefónica.
O2 Ireland chief financial officer Paul Whelan said the company was pleased with the performance, given the increased level of competition.
Meanwhile, 02 chief executive Peter Erskine said today that the Telefonica unit was likely to offer customers fixed-line services across its territories in the future, effectively taking on 02's former parent firm BT.
'It is very possible that we will be learning from what we have done in Germany and the Czech Republic and doing similarly in the rest of our business,' Erskine said today. 'We do believe although convergence has been talked about for many years, it's now what customers will want,' he added.
Erskine said 02, which already runs fixed-line operations in Germany through Telefonica Deutschland and the Czech Republic, would look at both the possibility of buying a fixed-line business in its core British market as well as the option of leasing network capacity from former UK state owned monopoly BT.
'We are playing all the horses and working out which is the one for the short term and the long term,' he added.
