Alleging irregularities in allocation of additional spectrum during the NDA regime, the CBI on Friday filed a chargesheet in a Delhi court against three telecom companies.

The CBI accused them of causing a loss of Rs. 846 crore to exchequer.

In its chargesheet filed before special CBI judge OP Saini, CBI named  Bharti Airtel, Vodafone India, Hutchison Max and Sterling Cellular, and former telecom secretary Shyamal Ghosh as accused.

The court has fixed January 14 for considering the chargesheet.

The CBI alleged that the DoT had increased the base spectrum for telecom companies from 4.4 MHz to 6.2 MHz during former telecom minister Pramod Mahajan's tenure.