The European Commission turned down a request from the UK’s competition authority to lead the probe into Hutchison 3 UK’s proposed acquisition of Telefonica O2.

The commission concluded it was better placed than the Competition and Markets Authority (CMA) because of its recent experience in assessing deals in the mobile sector.

In support of its argument, the EC pointed out it has run investigations in recent years in both mobile and fixed sectors in Denmark, Germany, Ireland, Netherlands, Spain and the UK.

If the commission leads on Hutch/O2 too, then there will be greater consistency in the application of merger rules, it argued.

The CMA, which is assessing BT’s proposed £12.5 billion offer for EE, made its request about the Hutch-O2 deal in October. Member states can use the so-called Article 9 to apply to consider mergers nationally rather than in Brussels, providing the competitive effects of any deal are purely national.

Nonetheless, the commission said it will continue to cooperate with the UK competition authority in its assessment of the case.

The EC’s own in-depth investigation in Hutch/O2 opened on 30 October 15 and has a deadline of of 18 April 2016 to reach a final decision.