South Korea’s three mobile operators have put aside their usual fierce rivalries and teamed up to fight the record high reserve price the Ministry of Science, ICT and Future Planning (MSIP) set for the 2.1GHz band in next month’s auction.

The MSIP put the base price of 20MHz of the spectrum at KRW382 billion ($309 million) for a five-year licence, the Korea Times reported. The reserve price for the 140MHz of spectrum being sold in the auction exceeds KRW2.5 trillion.

The three operators — SK Telecom (SKT), KT and LG Uplus – joined forces after the regulator announced the highest ever reserve price for a spectrum auction last Friday. The operators said the auction is a huge burden at a time when they need to expand investments to build 5G networks, the Times reported.

SKT and KT currently operate 4G services on 60MHz and 40MHz in the 2.1GHz band, respectively. The 20MHz to be auctioned is held by SKT.

The MSIP said it will reallocate the remaining 40MHz based on the auction price for the 20MHz block.

Although LG Uplus won’t be affected by the regulator’s reallocation of the 2.1GHz band, it has complained that the reserve price is the highest in history and questioned why the 20MHz block has a five-year licence, while other bands up for sale will be auctioned with 10-year licences.

The company claimed a five-year term is not enough for operators to make a return on their investment.