The decision is based on a legal opinion by senior advocate P P Rao who had been asked by the telecom department to clarify the apex court's orders.
Various industry bodies, including Assocham, the Cellular Operators Association of India (COAI), and Idea Cellular managing director Himanshu Kapania, had been insisting that the SC order should have lead to the quashing of 141 Unified Access Service (UAS) licences, including Tata Tele's 19 GSM permits, instead of 122 as undertaken by the government.
Dual-technology licence holders offer mobile offering services on both GSM and CDMA platforms. Tata Teleservices offers GSM services in all telecom circles of the country except the Northeast, Jammu & Kashmir and Assam.
DoT is expected to soon inform all the groups about the legal opinion of the senior advocate.
According to a DoT note, Rao said there were two sets of applicants. One set was of those that applied for UAS licences till September 25, 2007 and the second set of existing licensees seeking approval to use dual-technology spectrum.
Rao added the SC judgment had not mentioned quashing of the approval given for use of dual-technology spectrum to the existing players that had been given licences before the issuance of two press releases on January 10, 2008.
"The allocation of spectrum quashed by the Supreme Court is limited to the cancelled licences. The existing licensees are not to be affected, as neither their licences were cancelled nor their spectrum quashed," Rao noted.
Tata Tele had got its CDMA licence in 2005 and was allowed in January 2008 to operate GSM services under the same licence through the dual-technology route.
The Supreme Court had on February 2, 2012, quashed the licences given to private firms on or after January 10, 2008, pursuant to two press releases issued by DoT on January 10, 2008.
In one release, DoT had said letters of intent would be issued to all eligible players on the date of their application (if applied on or before September 25, 2007).
In the second, DoT had asked the dual-technology applicants to collect DoTs response on the same day at a specified time.
Rao noted that both DoT and the Telecom Regulatory Authority of India (Trai) had correctly understood the meaning and purport of the Supreme Courts directions.
He added that the interpretation by various groups that 141 UAS licences ought to have been cancelled, and not 122, is not correct.
"The language of the Supreme Court judgment was very clear and unambiguous and it needed to be read and understood with reference to the two press releases issued on January 10, 2008," said the senior advocate in his opinion.
The move also benefits Reliance Communication, which has 22 dual technology licences in the country. RComs UAS licences were amended on October 18, 2007, to also include offering GSM services.
Earlier, COAI had lobbied that the number of licences to be cancelled to go up to 163.
The industry body, which lobbies for incumbent GSM players, also wanted the spectrum given to RCom under the dual-technology route to be taken back.
It had also sought a separate ruling from the Supreme Court.
Tata Teleservices' CDMA licences for the three circles -- of J& K, Northeast and Assam (which it got in 2008) are among the 122 quashed by the Supreme Court directive.
Other companies who got their licences cancelled include Uninor, Loop telecom, Etisalat DB, Videocon, STel, Sistema Shyam Teleservices and Idea Cellular.