(Telecompaper) [Update] Germany's Federal Network Agency (BnA) is considering whether O2 and E-Plus will have to give up some of their frequencies if they proceed with their merger, reports German newspaper 'Frankfurter Allgemeine Zeitung' (FAZ). The regulator believes that their GSM licences as well as their UMTS licences are tied to their competitive independence. According to letters sent to E-Plus CEO Thorsten Dirks and Telefonica Germany CEO Rene Schuster, and seen by the FAZ, the regulator warns it could revoke their frequency allocation in an extreme case. BNA will examine the merger proposal and and has asked the companies to provide information within two weeks, according to the letter dated 25 July of this year. The agency will have to review whether the frequencies will still be "efficiently used" and whether the combination would hamper competition plus seeking comments from competitors, according to Bloomberg also citing from the letters. Both Telefonica and E-Plus commented to Bloomberg that the letters are part of their goal to receive quick regulatory approval.