(Telecompaper) The European Commission has opened an in-depth investigation into the planned acquisition of KPN's E-Plus by Telefonica Deutschland, rejecting a request from the German competition regulator to examine the proposed merger of the third- and fourth-largest mobile operators in Germany. The EC has 90 working days, until 14 May 2014, to take a decision. The investigation will focus on the possible reduction in competition in the retail mobile telephony market as well as in the market for wholesale access and call origination on mobile networks in Germany. Moreover, the commission has concerns that after the transaction the remaining MNOs might have fewer incentives to grant access to their network to MVNOs and service providers. Prospective and existing MVNOs and service providers would have less choice of host networks and hence weaker negotiating power to obtain favourable wholesale access terms.