Thailand’s third largest operator True Move is expected to launch 4G service on the 850MHz band by Q3 after the telecoms regulator approved the upgrade of its existing 3G network it operates in partnership with state-owned CAT Telecom.

True, which has a wholesale-resale agreement with CAT, will fund the 4G network upgrade on CAT’s 15MHz of spectrum and be allowed to rent up to 80 per cent of the network’s capacity until 2025, the Bangkok Post reported. True has installed almost 14,000 3G base stations on the low-frequency 850MHz band.

In addition to the 850MHz spectrum, True has 15MHz of 2.1GMHz spectrum as well as 15MHz of 1.8GHz and 10MHz of 900MHz it won in auctions in November and December. The operator acquired the two blocks of 4G spectrum for a staggering THB116 billion ($3.22 billion).

True has a 22 per cent market share and 11 per cent of its 18 million connections are 4G, according to GSMA Intelligence. Second ranked dtac has about 2.2 million 4G connections, which account for 8.6 per cent of its total subscriber base.

Meanwhile, CAT aims to upgrade 20MHz of unused 1.8GHz spectrum to 4G. Dtac has a concession from the state-run firm to use 50MHz of 1.8GHz spectrum, which expires in 2018, but has launched service on only 25MHz. CAT transferred 5MHz of the unused spectrum to the National Broadcasting and Telecommunications Commission for the 4G auction in November and has asked the regulator to use the remaining 20MHz to offer its own 4G service.