Mobile phone operator Three Ireland is to launch its 4G network on January 27.

The network will be the third here to begin offering a fourth generation service, following in the footsteps of Eircom and Vodafone who launched last year.

The Three 4G signal will initially only be available in Galway, Limerick and Waterford, where there will be two thirds coverage, and Dublin and Cork where there will be 40% coverage.

However, the company says its total population coverage will grow quickly during the year.

Three will offer both Bill Pay and Prepay users 4G access for free until July 31, provided they have a compatible phone and carry out a software update that will be available in the coming weeks.

After that, Bill Pay customers will have to purchase an add-on for €4.99 a month. The charging structure for Prepay customers has not yet been revealed.

Three is currently awaiting regulatory approval from Brussels for its €850m purchase of O2. The European Commission opened an in-depth competition investigation into the plans in November, with a final decision due in March this year. 

O2 has not yet launched its 4G service in Ireland.