Advanced Info Service Plc (AIS) has threatened to ask the national telecom regulator to investigate True Corp Plc for allowing only its cellular subscribers to vote via SMS for contestants in a popular reality show.

The threat is part of its retaliation against True's plan to ask the National Telecommunications Communications (NTC) to look into whether AIS's latest call promotion would overload smaller networks and prompt call jams.

AIS vice president Titipong Khiewpaisal said yesterday that if True filed a case against AIS with the NTC, AIS would retaliate in kind against True.

True Corp had allowed subscribers of its cellular operator, True Move, to vote via SMS for contestants in the "Academy Fantasia 3" reality show, which was screened on the corporation's UBC True pay-television station. The show ran from July 3 to September 9.

"Academy Fantasia", launched two years ago by UBC True, is the country's most popular reality show, where viewers can vote

for and rate their favourite

contestants via SMS. The contestants compete in a singing contest.

The plan quickly attracted criticism from AIS and Total Access Communication (DTAC) that the SMS limitation to True would damage the wireless-content industry.

True Move also gave away SIM cards to all 480,000 UBC True subscribers.

AIS's latest prepaid promotion charges Bt1 per call for during off-peak hours and Bt1 per minute during peak hours.

True believes the AIS package will prompt a price war in the industry, followed by the call jams on all cellular networks.

AIS has more than 17.5 million subscribers, True Move more than 5 million and DTAC more than 10 million.