Arqiva, Cable and Wireless, and Telefonica are bidding for licences in each of the northern, central, and southern regions, while Airwave has made a bid for the northern region licence.
Experts within the industry believe Decc is likely to award two regional licences to one bidder and the final regional CSP licence to another.
One said the option of dividing the northern, central and southern regions two and one would represent better value for money than appointing one licensee per region, while also providing a back-up option should one of the licence holders run into difficulty.
Decc denied the rumour. A spokeswoman said the outcome of each of the regional competitions will determine how many CSPs there are, and “any combination is possible”.
The final four bidders have been invited to provide final tenders and Decc expects to announce the successful bidder for each region in July.