This brings the number of companies picking up the documents to five.
TrueMove H Universal Communication, the mobile-phone unit of True Corp, was the first company to pick up the documents, on January 3, a day after the NBTC made the documents available.
Dtac TriNet Co Ltd, a subsidiary of Total Access Communication (DTAC), picked up the bid documents on Wednesday, followed by state firms TOT and CAT Telecom.
The documents will be available until February 3 and bids must be submitted on February 4.
The NBTC will auction the 700 megahertz, 1800MHz, 2600MHz and 26 gigahertz spectrum licences.