Germany’s communications regulator confirmed it was processing applications from four companies to take part in its 5G auction, a process scheduled for late March despite ongoing legal action by operators.

Although regulator Bundesnetzagentur did not reveal the identity of the contenders, given comments last week from potential newcomer United Internet, it looks likely that company will take part alongside the market’s three existing operators: Telefonica, Deutsche Telekom and Vodafone.

Another potential bidder floated by German media was MVNO Freenet, however in an interview with Handelsblatt last week its CEO Christoph Vilanek ruled his company out due to the expected cost of acquiring spectrum and uncertainty around 5G licence rules.

The regulator said it would “quickly assess” the suitability of the applications as it aims for an auction starting date in the second half of March. But this date could be under threat as the country’s three operators reportedly filed legal action against the terms of the auction.

Formal challenges followed a number of grievances including the extent of coverage obligations and some of the concessions being made to encourage a new entrant.