A bench headed by Justice H L Dattu which perused the status report and other materials filed in sealed cover on the progress of the probe, said "after the opinion of Attorney General(Mukul Rohatgi), CBI has talked about the filing of the charge sheet at the end of the particular month".
The bench made the remarks after senior advocate K K Venugopal, who placed the status report on behalf of the CBI, said that the apprehension was not justified that the agency was not moving forward for filing the charge sheet.
He explained the sequence of events for delay due to difference of opinion between CBI Director and Director Prosecution on filing of charge sheet which was finally decided after AG's opinion.
"The Attorney General has concurred with the opinion of Director of Prosecution and not with the CBI Director," Venugopal said, adding that "all steps have been taken for filing of the charge sheet and that is going to be done".
He said that Rohatgi's July 27 opinion was received by the CBI on August 4.
CBI had earlier said that its domestic investigation was complete but was facing hurdles in its overseas probe as it was not getting cooperation from Malaysian authorities.
The Aircel-Maxis deal also involved Kuala Lumpur-based business tycoon T Ananda Krishnan.
Maran has been accused of "forcing" Chennai-based telecom promoter C Sivasankaran to sell the stake in Aircel to Malaysian firm Maxis Group in 2006 owned by Ananda Krishnan.
Venugopal said Malaysian authorities have been asking clear proof of criminality and their Attorney General wrote strong letter to Indian Embassy officials in Kuala Lumpur.
At this, the bench said, "Union of India has to take up the matter with Malaysian Government".
The NGO, Centre for Public Interest Litigation and Janata Party President Subramanian Swamy, had filed applications in the apex court alleging that Foreign Investment Promotion Board (FIPB) approval to the Aircel-Maxis deal was granted fraudulently.
The agency had earlier said the overseas probe was being delayed due to the influence of the firm's owner in Malaysia who is "powerful politically".
The agency had submitted that overseas probe was important to track the money trail as the funds for the deal had come through Mauritius.
The agency in July 2011 had placed a status report in the court stating that during 2004-07 when Maran was Telecom Minister, Sivasankaran was coerced to sell the stake in Aircel to Maxis Group.
The report, part of which was read, had said the Malaysian firm was favoured by Maran and was granted licence within six months after taking over Aircel in December 2006.
Maran was the Telecom Minister between February 2004 and May, 2007.