The number of traditional text messages being sent by Irish mobile users has continued to fall sharply, according to data from the communications regulator, ComReg.

Irish customers sent almost 1.9bn text messages between April and June, according to its latest market report, which was down 23.2% on the same three month period of 2013.

The number of multimedia messages being sent was also lower, falling 6.1% year-on-year.

While text messaging has been a hugely popular service in Ireland for many years, its usage has been in free-fall due to the proliferation of data-based messaging services like Whatsapp.

Quarterly usage of text messages has fallen by 42.3% since its peak in late 2011, according to ComReg data.

The amount of minutes spent on mobile calls has remained broadly stable, however, despite the increasing availability of data-based voice services on smartphones such as Viber.

There were 2.9bn minutes of call time during the second quarter of 2014, according to the figures, which was a slight increase on the same three months of last year.

Unsurprisingly, data usage has continued to rise sharply, with 15.7 petabytes (15,724,000 gigabytes) used during the quarter.

This is a 54% increase on the same period of 2013.

This was driven primarily by the increasing usage of smartphones in Ireland, with 59% of all mobile voice subscriptions now using such devices. This is up 14.7% on a year ago.

Despite this increased activity in the mobile market, average revenues generated from each customer were down €2 per month to €25.

In the wider broadband market, ComReg said that total subscriptions - counting both fixed line and mobile services - fell 0.3% to 1.7 million by the end of June.

It set the broadband penetration rate at 67% by the end of the second quarter, though as it includes both mobile and fixed services there may be instances where one household is counted twice.