The approval follows additional concessions made by Hutchison in April to secure the deal.
Hutchison must sell approximately 30% of the merged company's network capacity to two mobile virtual network operators (MVNOs), as well as divest five blocks of spectrum in the 900MHz, 1800MHz and 2100MHz bands to the MVNOs.
The EU has also obliged the company to continue a network-sharing agreement with Irish operator Eircom.
Telefónica agreed the sale of O2 Ireland to Hutchison Whampoa’s subsidiary, 3 Ireland, in June last year.
However, there were concerns that the deal will shrink competition by reducing the number of operators in Ireland down to three and the EU launched an investigation at the end of last year.
The EU is also investigating the $12 billion acquisition of E-Plus by Telefónica Deutschland. A takeover would combine the two companies and create a player of similar size to the two leading operators, Deutsche Telekom and Vodafone.
