Eir said its revenue rose by 2% to €304m in the first quarter of 2023 - in line with expectations.
But the company's EBITDA decreased by 9% to €128m on an annual basis on the back of increased sales and marketing and mobile network.
Operating costs of €105m increased by 6%, with non-pay costs up by 15% and pay costs decreasing by 3%.
Eir said its fibre broadband base increased by 2% year on year to 845,000 customers.
It noted that multi-play bundling accounted for 46% of eir fixed households, up 5 percentage points on last year.
Eir said its total mobile customers now stand at 1.339 million, up 9% on the same time last year, while it now also has 87,000 eir TV customers, an increase of 9%.
Oliver Loomes, eir's chief executive, said the first quarter of 2023 proved a solid start to the year and the company remains on course to add another 250,000 homes and businesses to its fibe-to-the-home broadband network, already available to more than one million premises.
"When combined with eir's existing fibre-to-the-cabinet network, more than 2 million premises now have access to fibre broadband," the CEO said.
"Eir is investing €250m annually in new technologies and networks which is truly transforming Ireland, allowing individuals and businesses to access new services or markets at speeds and capacity unimaginable before now," he added.
Oliver Loomes also said that people are becoming increasingly reliant on mobile data to live and work.
The company recorded a 41% increase in the use of mobile data in the first quarter of 2023 compared to first quarter of 2022.
"Eir has responded to this growing demand for data by, not only enabling incredible 5G speeds on all of its mobile plans, but by significantly expanding its 5G mobile network, which now offers ultrafast data access to customers across 547 towns and cities in Ireland," the CEO said.
"The market has responded to this investment, with this quarter demonstrating yet another significant jump in eir mobile customers, up 9%, or 105,000, on the equivalent period last year. eir TV has also grown by a similar proportion, showing that a growing number of customers are availing of product bundling to generate extraordinary value for their households and families.
Yesterday eir was hit with a €2.45m penalty by the Commission for Communications Regulation, ComReg, as part of a settlement following investigations into the overcharging of its customers.
Around 76,000 customers may be affected with up to €6.7m in refunds potentially involved.
Eir said it will implement a series of "backward-looking measures" to identify customers who have been overcharged historically and have not been refunded for the overcharge and will refund these customers appropriately.
