Leading GSM telecom operators Airtel, Vodafone and Idea along with their association COAI  approached the Supreme Court with a plea to be made in the case relating to 2G spectrum allocation scam which is being probed by the CBI.

Senior Advocate Fali S Nariman, appearing for them, submitted before a bench comprising justices G S Singhvi and A K Ganguly that they should be heard in the matter as they have challenged the Centre''s policy of allocating GSM spectrum to CDMA operators under dual technology to service providers like Reliance Communication and Tata Teleservices.

It was alleged that the two companies were alloted GSM spectrum under the dual technology regime ignoring several applicants who had applied before them for the licence.

"It is in the interest of justice that the applicants be permitted to intervene at the hearing and to make appropriate submission especially the submission that the investigation by the CBI should not in any way be influenced by the TDSAT judgement (allowing the use of dual technology)," the GSM lobby group COAI along with leading operators -- Airtel, Vodafone and Idea -- said in its application.

It is pointed out in the application that GSM telecom operators and Cellulor Operators Association of India should be allowed to present their views before the court as the CBI is also probing into the loss caused to the public exchequer due to the government decision of allowing use of dual technology.

It pleaded that the government decision was illegal, arbitrary and was intended for the benefit of a few telecom companies.

The impleadment application was however opposed by the Reliance Infocom and Tata Teleservices which pleaded that there was no need to implede COAI and other GSM operators.