Telefonica tweaked the concessions it offered to make to secure European Union approval for its proposed acquisition of KPN’s German unit E-Plus, reports Reuters.

Telefonica last month offered to lease spectrum above 2GHz and provide access to its network to rivals, in an effort to placate the concerns of the EU’s antitrust body.

Rivals and third parties were subsequently invited to provide their views on the package of concessions for the proposed €8.6 billion deal. The deadline for comments passed last week.

A spokesperson told Reuters that the company has submitted a modified set of concessions to the European Commission based on the feedback from the consultation.

The modifications include “fine-tuning” the conditions for access to the combined company’s network, the Telefonica representative said, adding that the Spanish-based group has not offered to lease lower-frequency spectrum.

While both the EC and Germany’s telecoms regulator reportedly want Telefonica and E-Plus to give up spectrum at 900MHz and 1.8GHz as a condition for any merger approval, it appears the Spanish giant is still only willing to give ground at the higher frequency band.

It is believed the first package of concessions was not deemed sufficient to provide the opportunity for a fourth national mobile operator to take the place of E-Plus, ensuring the German market remains competitive.

A second round of feedback with a deadline of 5 May is now being conducted by the European antitrust body, according to sources. The deadline for the European Commission has been set for 23 June.

Germany, along with Ireland, is seen as an important test case for the commission on its willingness to reduce the number of mobile network operators in EU member states.

Hutchison’s 3 Ireland has also submitted a number of potential “remedies” to try and allay anti-trust concerns about its bid for Telefonica’s Irish unit.