The Czech Republic has launched a tender for selling spectrum for 5G networks, its telecoms regulator CTU said on Friday.

The auction of 5G spectrum in the 700 MHz and 3.4-3.5 GHz bands is aimed at boosting competition in a market where high prices have long been a gripe of customers and politicians.

Interested bidders have until Sept. 30 to apply, CTU said.

The regulator said that after public consultations it had reserved a section of 2×10 MHz in the 700 MHz band for new entrants.

CTU also set spectral limits in both bands and said existing operators would need to provide national roaming services for newcomers should they succeed in the auction.

Telefonica’s O2 Czech Republic, Deutsche Telekom’s T-Mobile and Vodafone are the existing operators.

“Given the mistakes and problems in the conditions, it can be expected that the auction will result in clashes at courts and also the European Commission,” Vodafone said in a statement.

T-Mobile said it was surprised by the CTU’s action.

“We have to study the conditions and ponder our next steps, including possible charges,” T-Mobile spokesman Jiri Janecek said.

Last month, O2 Czech Republic complained to the European Commission over some 5G auction conditions.

The planned auction for new 5G frequencies has been hit by delays as the state seeks to attract a fourth operator.

In January, the former head of CTU resigned over government changes to the auction, saying they risked slowing the rollout of the technology and were likely to result in court disputes.

O2 in July started commercially offering 5G mobile services in a small part of Prague and Kolin. O2 said its 5G will be available to 15 percent of the capital’s population during the summer.

O2 launched the technology at a frequency of 3.7 GHz, said Jan Hruska, O2’s technology director.

O2 is building the network together with Cetin. O2 launched 5G with Ericsson last year in Cologne, and is testing with Huawei and Nokia.

Vodafone would test 5G in Karlovy Vary, where commercial operation is also ready, as well as in Usti nad Labem and Jesenik.

T-Mobile, which announced a 5G test network on the campus of the University of Mining in Ostrava, is also preparing a commercial launch.