The UK needs to look at why three of the world’s leading operators – Deutsche Telekom (DT), Orange and Telefonica – are looking to reduce their involvement in the market, Ronan Dunne, O2 UK CEO, said.

Talking to The Telegraph, he said: “If you were the regulator or minister responsible for telecoms in the UK, you would be surprised that in one of the most open economies in the world that has strong foreign direct investment, you would be surprised that three of the largest telecoms companies in the world are selling. It does imply there is something not quite perfect in the model.”

Telefonica is in the process of selling O2 to CK Hutchison, which will merge it with its own 3 UK unit. Meanwhile, fixed incumbent BT is buying EE, the mobile operator jointly owned by Deutsche Telekom and Orange.

Actually, following the BT-EE deal, Deutsche Telekom will hold a 12 per cent stake in BT and Orange will hold a four per cent stake, although it’s certainly true they are reducing their direct involvement in the UK market.

For a three year period, DT will not be able to increase its share in BT above 15 per cent or Orange above 4 per cent, and the companies cannot sell down shares for 18 and 12 months respectively, although Orange can sell shares to DT up to the 15 per cent limit.

If both deals are approved then the UK will see a reduction in the number of mobile operators from four (EE, Vodafone, 3 and O2) to three (BT/EE, Vodafone and 3/O2)

The combination of BT and EE will control 45 per cent of spectrum in the UK, compared with 27.5 per cent for Vodafone and 27.5 per cent for 3/O2 , said Dunne.

Both 3 and O2 won less spectrum than they wanted from the country’s last auction. For 3 this meant closing an unlimited data tariff to conserve its spectrum supply. Dunne feels aggrieved, arguing it will struggle to match offerings from BT or Vodafone.

“We will have the same spectrum combined as Vodafone has today and less than EE has even before it combines with BT,” he said.

Spectrum share is expected to be part of Hutchison’s argument to regulators about why the O2 deal should be given a green light. The company will make its submission to Brussels in September.

However, the EU has not yet formally stated it will investigate 3/O2. A media report earlier this year said the UK’s Competition and Markets Authority (CMA) wanted to investigate the deal.

BT’s takeover of EE is being investigated by the CMA.