The merger between Thailand-based operator Dtac and True has hit a regulatory roadblock over fears of competition being stifled despite initial approval.
A supervisory authority for regulator National Broadcasting and Telecommunications Commission (NBTC), known as NBTC super board has urged NBTC acting Chairman Sukit Khamasundara to prevent the merger from going through, citing competition concerns.
"The purpose of the document submission is to raise public awareness and involvement in fact-finding, analysis and criticism, which will lead to an appropriate conclusion," said the board.
Concerns stem from the Thai telecoms market being one with already only a few players, reported Nikkei Asia.
The merger will leave two main operators in Thailand. AIS is currently the market leader with a 46% share, whereas Telenor-owned Dtac holds 22% and True brings 32% to the table if they were to merge.
The merger also saw criticism from the Thailand Consumer Council which warned users might face higher bills, citing a study from the UK which showed a potential 20% rise in tariffs if the Western European country was to see its MNOs cut from four to three.