South Korea’s three mobile operators applied earlier this week to participate in the spectrum auction later this month that will offer five blocks in the 700MHz, 1.8GHz, 2.1GHz and 2.6GHz bands.

The sale of 140MHz of spectrum, with a total reserve price of KRW2.5 trillion ($2.6 billion), is expected to raise far more than that amount for the government given operators’ keen interest. The auction is expected to begin next Monday after the applications are reviewed.

The stakes are high as each operator is looking to acquire bands adjacent to their existing ones to increase efficiency in operating their networks with broader bands, the Korean Herald reported.

If no winners emerge in the first round, the bidders go onto a second stage involving a one-round sealed-bid auction process.

Last month SK Telecom (SKT), KT and LG Uplus put aside their usual fierce rivalries and teamed up to oppose the record high reserve price set by the Ministry of Science, ICT and Future Planning (MSIP) for the 2.1GHz band. The MSIP put the base price of 20MHz of the spectrum at KRW382 billion ($309 million) for a five-year licence.

The operators have said the auction is a huge burden at a time when they need to expand investments to build 5G networks.

The three operators spent KRW2.9 trillion on spectrum in 2013 and KRW1.7 trillion in 2011.