Highly placed sources said Rohtagi's opinion is being analysed by the officials handling the probe.
They said the AG's opinion is not binding on the agency but rarely CBI has taken a contrary view.
The sources said a considered view will be taken how to finalise a legally sound charge sheet based on the available evidence in the light of observations of Rohtagi.
Meanwhile, Malaysian telecom giant Maxis has written to Directorate of Prosecution, O P Verma, CBI claiming that the deal was done with the full consent of the Aircel Board of Directors.
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"Chairman Aircel informed about the Board that the offer price quoted Ms Maxis Communication Berhad is quite attractive...Exchange of correspondence with Mr Sivasankaran in the course of negotiations which will show that Mr Sivasankaran was a willing and that he had obtained the valuation that he so desired or his investment in Aircel," it said.
The sources said the matter was escalated to the office of the attorney general as there was a difference of opinion between the views of investigation team and the CBI director Ranjit Sinha on charge sheeting Maran brothers in the case.