Indonesia's anti-trust agency, KPPU, will escalate an investigation into alleged price-fixing of tariffs for mobile phone text messages, a member of KPPU's investigative team, quoted by a Reuters report, said.
The Reuters report said the KPPU's chairman said last week that the agency had launched a probe into alleged price fixing of tariffs for short message services to all operators.
News of an escalation of the investigation sent telecommunication shares tumbling, dragging the overall market to its lowest in three weeks, the report said.
'In the council meeting on December 14, we decided to go to an advanced investigation on all operators of SMS services,' Erwin Syahril of the KPPU was quoted as saying.
'The investigation document will be distributed to all operators as soon as possible and we will conduct the probe for the next 60 days,' he added.
The Reuters report further said shares of the country's largest telecommunication company PT Telekomunikasi Indonesia, which controls the largest mobile phone operator PT Telekomunikasi Selular , plunged as much as 4.8% after the news.
Its main rival, PT Indosat dropped 2.7%, the report added.
The latest anti-trust investigation follows a ruling last month over alleged price fixing in mobile phone calls by the country's two biggest mobile phone operators, the report further said.