The regulator plans to grant three licences to the three winning bidders within the next three weeks, according to Settapong Malisuwan, chairman of NBTC's telecom committee.
"We expect to approve the auction results Thursday at the telecom board meeting," said Col Settapong.
The bid results will be officially endorsed if three out of five members of the telecom committee vote in favour. At present, only one of the members, Prawit Leesatapornwongsa, has indicated he may object.
Mr Prawit, who opposed the auction from the start, said he is waiting for details about the bidding and lack of rivalry from the NBTC. If it turns out there really was no competition during the auction, he would reject the result, he said.
NBTC member Supinya Klangnarong, who is opposed to the revised terms and conditions of the 3G bid, is calling for the agency to delay endorsement to allow the regulator to "contain the damage".
Ms Supinya said the NBTC's credibility is at stake and she has come up with three options for the watchdog to consider to fix it.
First is to scrap the bid results but this will hold up 3G services. The second option is to lay down measures to show that the NBTC does not harbour collusion. The last option is to announce the price ceiling the three operators will be subject to within three months to ensure that consumers will not be overcharged.
"The NBTC is cast in a negative light. We need to undo the damage. When the state is set to lose [income] we have to make sure consumers have access to good and affordable services," she said.
However, she admitted that the proposal is unlikely to protect the watchdog against lawsuits.
According to Col Settapong, any action against the NBTC's auction should occur within 90 days from the result being formally certified or the licences granted.
A bid to challenge the auction results should certainly be filed before actual 3G services are rolled out to limit the impact on consumers, he said.
Col Settapong insisted the threat of lawsuits will not affect the licensing process as long as there is no evidence of collusion among the bidders.
The NBTC is ready to fight any litigation, he said.
The commission has set up a legal team chaired by its commissioner Suthipol Taweechaikarn to handle legal challenges including petitions to the National Anti-Corruption Commission.
The long-overdue sale of 3G mobile spectrum bandwidth on Tuesday attracted a storm of criticism after only three of the nine available slots attracted competition. Six slots, representing 5MHz each, were sold at the minimum reserve price of 4.5 billion baht.
The sale brought in 41.625 billion baht overall, only 1.125 billion or 2.78% above the reserve price.
Col Settapong said critics of the auction cited the study conducted by Chulalongkorn University which recommended that the value of the 3G spectrum be 6.44 billion baht for a 5MHz slot. However, he said the university's working panel proposed the reserve price should be set at 67% of the valuation price.
The NBTC ended up setting the reserve price at 4.5 billion, or 70% of the actual frequency value, he said.
"This study could be a defence against accusations that the final auction prices were too low," Col Settapong said.
Acting Auditor-General Pisit Leelavachiropas said Wednesday it is too early to say if the three bidders had engaged in price collusion.
However, he said the NBTC has so far been transparent.
"The focus is if the watchdog will endorse the auction. I hope the consumers will get good and inexpensive services," he said.
Democrat leader Abhisit Vejjajiva Wednesday called on the NBTC to clearly explain the terms and conditions of the auction and be prepared for the consequences.
"We heard criticism the agency is giving the operators a windfall. So the NBTC must start thinking about what can be done," he said.
An academic familiar with the 3G issue said a spectrum auction is based on two principles _ maximising revenue from spectrum sales in the short-run and efficiently allocating spectrum resources to operators that provide the greatest benefits to consumers through service quality with affordable prices. "The longer the 3G services are delayed in the country, the greater the damage to the economy will be."
A telecom engineer explained that the positions of the frequency band on the international standard 2.1 gigahertz spectrum contained no significant differences in technical advantages as claimed by the NBTC.
The 2.1-GHz spectrum is a clean and stable upgrade bandwidth for the future long-term evolution (4G) technology, he said.