It's official - the Telefónica takeover bid for the O2 Group has been accepted, which means that O2 customers are now part of the third largest telecoms operator worldwide by customer numbers, and the second largest mobile operator outside China.

Joining the Telefónica Group is a momentous move for O2. It brings together two dynamic and successful companies with real momentum and ambition. Not only does it give O2 the extra strength of a huge organisation and the ability to leverage better deals for O2 customers (on issues such as technology, handsets, roaming and i-mode), but it also gives O2 a fantastic opportunity to really go from 'good to great'.

"Telefónica have paid us the biggest compliment possible in asking us to continue as we have been, backing us to keep delivering the goods and allowing O2 to be run as an autonomous business division. This move is about carrying on the O2 way of doing business, but doing it within a much bigger market place. We welcome in the new era and look forward to the start of something great," an O2 spokesman explained.

Initially the European Commission expressed concerns that the acquisition would result in distortions of competition on the market for international roaming services, as Telefónica are members of the FreeMove low-cost roaming alliance, where it cooperates on roaming with several of Europe's other top wireless players: France Telecom SA, Telecom Italia SpA and Deutsche Telekom AG. O2 is a member of the smaller Starmap alliance, where a range of smaller telecommunications cooperate in a similar framework.

However, the deal was approved in January by the European Commission, with a condition that it quits the FreeMove alliance. "In light of this commitment, the Commission has concluded that the transaction will not significantly impede effective competition in the European Economic Area," a European Union statement said.

Telefónica, the world's fifth-largest telecommunications company by market value prior to the acquisition, plans to pay roughly EUR28 billion for 02. The combined operators will have annual sales of around EUR40 billion. The deal means that in addition to O2's customer base in Ireland, Telefónica will be able to enter the fiercely competitive British market and to re-enter Germany which it abandoned in 2002 after failing to build an operation there.