Magyar Telekom (a subsidiary of Deutsche Telekom) and Telenor Hungary entered into a cooperation agreement on the sharing of mobile frequencies and the joint development and operation of their 4G networks in the 800 MHz spectrum band. The cooperation covers the whole territory of Hungary apart from Budapest. While the National Media and Infocommunications Authority approved the cooperation, the Hungarian Competition Office launched an investigation concerning the arrangement. Although network sharing arrangements are unprecedented in Hungary, many previous cases from across the EU show that well designed structures bring economic benefits outweighing potential competition concerns, hence competition law should not form an obstacle to the joint exploitation of new mobile network technologies.