The auction is likely to take place this month, officials of the Bhutan Infocom and Media Authority (BIMA) have said.

An informed source in the Thai telecom industry said that Bhutan initially invited Advanced Info Service (AIS), Thailand's largest cellular operator, to participate in the bidding but Shin Corp, AIS's parent company, assigned ShinSat to the mission instead.

"It's because AIS has no history of doing business in overseas markets, while ShinSat has operated telecom businesses in Cambodia and Laos," the source said.

According to Kuensel, three of the four short-listed companies are joint ventures. The Singye Group is tied with Indian giant Reliance; Druktel, a consortium of Bhutanese companies, is linked with Airtel India; and ShinSat is amalgamated with Bhutan Steel. The Tashi Group is the only independent company taking part in the bidding.

The BIMA has ruled that the Bhutanese partner of any joint venture must hold an equity share of at least 51 per cent.

The winner of the 15-year licence is required to pay for 25 per cent of it up front, with the remainder to be paid throughout their operating tenure. The new operator must begin providing their service within one year of being granted the licence.

With about 200,000 potential cellular service users in Bhutan and Bhutan Telecom's Bmobile having already captured about 70,000 of them, the country's cellular market is not huge. But the operators in contention have their reasons for wanting to enter Bhutan.

"Mobile is the future of telecommunications," said vice chairman of the Tashi Group, Wangchuk Dorji. "Mobile is more than just conversing, it is the future and with globalisation, we can't ignore it."

"The business has a lot of potential," said the chairman of the Singye Group Dasho Ugen Tsechup Dorji. "There is enough market for two operators and at the end of the day it will be the services one provides for the customers that will attract users."

These developments are naturally of concern to Bmobile, which currently operates a monopoly cellular service in the country. When it started in 2003, BMobile was given a five-year licence that will end next June. The biggest question for BMobile is whether it will have to pay as much as its new private competitor when it renews its licence next year.

"Three of the companies are partnering with giants in the region," said Bmobile's general manager Tashi Tshering. "They are huge conglomerates with deep pockets and can afford to raise their bid to any limit, as the bidding will be conducted in an open auction. If their bid is beyond our financial capability I see only two options: either the government comes to our rescue or we stop providing our service."

Even if BMobile were able to renew its licence, Tshering said, it could still mean increased tariffs for its services.