Hutchison's Three Ireland has completed the €850 million buyout of 02 Ireland from Telefonica in a move that makes it the second biggest telecoms provider in the State.

The acquisition went ahead despite opposition from Comreg, the communications regulator. Comreg had said competition remedies proposed by Three to enable the deal to go through were "insufficient, inadequate and ineffective."

Authorities had been concerned that the deal, which has led to a reduction in the number of network operators from four to three, could lead to higher consumer prices.

Despite this, the European Commission cleared the takeover at the end of May, subject to a number of conditions which included allowing other providers, including UPC to become a movile virtual network operator (MVNO) offering services over Three's network.

The combined entity has a market share of about 40 per cent.

Three has said it intends to invest about €300 million in its network following the deal.

"This is a big day for the Irish telecoms market. We will now get down to the task of combining the strengths and talents of the two businesses to create a major force in the Irish mobile market, which will be good for competition, good for consumers and good for Ireland," said Three Ireland chief executive Robert Finnegan.