The European Commission said Thursday it expressed its concerns to Spain's Telefonica about the proposed 8.55-billion-euro ($11.7-billion) purchase of mobile operator E-Plus by the Spanish giant's German subsidiary.

"I can confirm that the Commission on Wednesday sent a statement of objections related to the proposed acquisition of E-Plus by Telefonica Deutschland," Antoine Colombani, the EC's spokesman for competition policy, said at a press conference.

He refused to provide details about the letter, saying it was "confidential" and only intended for viewing by the affected parties.

The spokesman said Telefonica Deutschland may now respond to the objections expressed by the EC and request a hearing to express its point of view.

The EC will issue a decision on whether or not to allow the acquisition by May 14, Colombani said.

Last December, the EC said it had opened an in-depth investigation to assess whether Telefonica's bid to acquire E-Plus, the German unit of Dutch mobile operator KPN, may violate EU rules by reducing competition.

European and German anti-trust investigators are still studying the legality of the transaction.

Telefonica agreed last July to acquire E-Plus from KPN for 8.1 billion euros ($11.1 billion) to create Germany's largest mobile-phone operator by customers and a powerful rival for Deutsche Telekom and Vodafone in that market.

A month later, Mexico City-based America Movil, a telecommunications giant controlled by Mexican magnate Carlos Slim and KPN's largest single shareholder, said it had agreed to vote in favor of the transaction after Telefonica agreed to improve the takeover terms.

Telefonica agreed then to raise the transaction value from 8.1 billion euros to 8.55 billion euros, with KPN to receive 5 billion euros in cash and a 20.5 percent stake in Telefonica Deutschland post-transaction.

The deal, if approved, will leave Telefonica with a 62.1 percent stake in the new Telefonica Deutschland. EFE