A bench led by Justice H L Dattu termed Maran's plea as pre-mature and said that an investigating agency cannot be stopped from filing a chargesheet if it deemed its probe was over.
Maran had claimed that the CBI probe was not completed and that it was in a haste to file the chargesheet, which was bound to have serious ramifications as far as his reputation was concerned.
The court however told him that if the CBI files a defective chargesheet, he could always come back to the court to demonstrate the flaws and have it quashed.
Meanwhile, Maran also claimed that Aircel-Maxis deal case was not related to the 2G spectrum matter.
The bench, which disposed of his petition as withdrawn, told Maran's counsel that all the contentions are being kept open for him to ague at an appropriate stage and before an appropriate forum.
The CBI was likely to file its chargesheet in the case on Thursday. The agency has taken into consideration the opinion of attorney-general Mukul Rohtagi, the representations sent by Maxis and material evidence collected by it through judicial requests and other methods.
Meanwhile, the Centre for Public Interest Litigation, an NGO that drew the Supreme Court's attention to wrongdoing in 2G spectrum allotments, has also accused the CBI director Ranjit Sinha of trying to shield Maran and Reliance Telecom.
The NGO cited three such instances and wanted Sinha to recuse himself from the case in a plea.
The CBI had earlier told the Supreme Court that it would be filing chargesheet against Maran in the Aircel-Maxis deal by the end of Augist. It had said that the decision to file chargesheet was taken after the Attorney General disagreed with the views of its Director Ranjit Sinha to drop the prosecution.
Senior counsel KK Venugopal, appearing for the CBI, had told the court that the chargesheet would be based on evidence collected within the country as the Malaysian authorities were refusing to cooperate.
CBI had 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.