Mobile phone contracts with the government have been declared illegal, but the ICT minister says service will not be interrupted even though all contracts must be renegotiated from scratch.
Information and Communication Technology Minister Sitthichai Pookaiyaudom said that the Council of State ruled on Monday that all five concession contracts were illegal.
Mr Sitthichai said negotiations could be completed within a few months, before the military regime is scheduled to hold elections and return democracy.
There was no initial reaction to the announcement from the mobile phone companies. The decision was not totally unexpected, as the military regime had already declared the contracts illegal and had asked the Council of State for a ruling.
There will be no move to freeze or cancel the concessions, in order to avoid disruption to services, Mr Sitthichai claimed.
The Big Three mobile phone companies, serving more than 20 million customers, are Advanced Info Service Plc of Singapore, the Singapore-listed Total Access Communication Plc (DTAC) of Norway, and True Corp, a subsidiary of the Charoen Phokphand conglomerate of Thailand.
Two minor companies are Hutch Communications, held jointly by Hutchison of Hong Kong and the CAT Telecom state enterprise, and Thai Mobile, a small company owned jointly by the state enterprises TOT Plc and CAT Telecom.