The attorney general is likely to give his opinion on Thursday on the alleged irregularities in awarding extra spectrum to Airtel and Vodafone during the tenure of the then Telecom minister Pramod Mahajan.
Following divergent views in CBI on whether a case was made out against the two companies, the issue was referred to law ministry seeking its advice.
Agency sources said a final view on the charge sheet in the case would be taken once AG gives his opinion on the matter which is likely to come on Thursday.
While a group of CBI officials believed a case against the two Telecom companies was made out as they were main beneficiaries of the laid down policy, another team of officials involved in decision-making differed, official sources said on Wednesday.
The matter, therefore, was referred to attorney general GE Vahanvati who is yet to give his opinion, the sources said, adding CBI would file a charge sheet in the case only after getting the opinion of the top law officer of the government.
The agency, in its FIR, had alleged the two companies had entered into a criminal conspiracy which resulted in a loss of over Rs 500 crore to the state exchequer.
Both companies have refuted any wrong doing in the case.
CBI had registered a case against the then Telecom secretary Shyamal Ghosh and deputy director general (Value Added Services) JR Gupta and unnamed officials of Bharti Cellular (now known as Bharti Airtel), and Hutchinson Max and Sterling Cellular (now known as Vodafone Essar) last November.
The agency had alleged the Telecom department had increased the base spectrum for Telecom companies from 4.4 MhZ to 6.2 MhZ during Pramod Mahajan's tenure as Telecom minister from 2001 to 2003 and also allocated extra spectrum on subscriber-based criteria.