Takorn Tantasith, secretary-general of the NBTC, said recently that the bonds would give the government funds in advance to spend to stimulate the economy and give people more choices for investment.

According to the rules governing the auctions of licences to bandwidth, the NBTC passes all upfront licence fees to the government.

The auction winners pay the upfront fees in instalments.

The Bt170 billion is made up of the total upfront fees for licences to the 1,800-megahertz spectrum their holders will pay in the second and third instalments and the total upfront fees of 900MHz licences that will be paid in the second, third and fourth years.

The NBTC has already received Bt80.78 billion as the first instalment of fees for the two 1,800MHz licences.

The second and third instalments of a combined Bt20.19 billion each will be paid in the second and third years.

The NBTC received Bt8.04 billion from True Corp for the first instalment of the 900MHz licence fee.

Advanced Info Service, which won the other 900MHz licence in the re-auction of the licence that was forfeited by a unit of Jasmine International, is expected to pay the first instalment on June 27.

They will pay the second and third instalments of a combined Bt8.04 billion for each instalment in the second and third years and a combined Bt119.79 billion in the fourth year.