Telenor Asia vice-president Tor Odland sent an email answer to Aftenposten, a Norwegian newspaper, on Monday saying the company received a call from the NBTC asking that it temporarily prevent its customers from accessing Facebook.
The NBTC told Thai media on Wednesday it would be more stringent with the qualifications of operators seeking to take part in the coming 1800MHz and 900 MHz auctions for 4G/LTE.
Although the regulator did not spell it right out, the two incidents were related. Thai media speculated the cause for the NBTC's suddenly tough move was the Telenor Asia comment.
Naew Na daily quoted Col Settapong Malisuwan, vice chairman of the NBTC, as saying Telenor Asia's announcement was inappropriate and disrespectful of Thailand's rules during this difficult time.
The NBTC would thoroughly scrutinise Dtac's shareholding structure and if it finds any cause to believe the company might have violated the 49% foreign shareholding rule, it would ban Dtac from taking part in the 4G frequency auction, Naew Na quoted Col Settapong as saying.
"In fact we are setting up a panel to examine Dtac's shareholding. If we find some inconsistencies we'll take legal action, not just ban it from the 4G auction," he reportedly said.
Thai Rath Online reported that Col Settapong had denied Telenor Asia's claim it was asked to block Facebook and added that the shareholding scrutiny would involve all operators.
According to Stock Exchange of Thailand data, Telenor Asia holds 42.61% in Total Access Communication Plc as of the latest shareholder register closing date on May 16 .
Total Access Communication Plc (Dtac) shares had fallen 5.35% to 115 baht at noon on Wednesday.
The NBTC was expected to hold a briefing later today.
As capital-intensive businesses, all mobile operators in Thailand are partially owned by foreign firms. For example, Singapore Telecom has a major stake in Advanced Info Service and China Mobile is buying 18% of True Corporation's shares.