Seven operators, including market leaders Bharti Airtel and Vodafone as well as new entrant Reliance Jio, will participate in India’s spectrum auction, starting 1 October.

The country’s Department of Telecommunications (DoT) revealed the list of applicants, following Wednesday’s deadline, with the list filled out by Idea Cellular, Reliance Communications (RCom), Aircel and Tata Teleservices.

RCom and Aircel this week signed a merger agreement, although the deal is not expected to close until 2017.

As expected, Telenor was the only notable absentee after it confirmed in July it would not take part.

The Norwegian operator is rumoured to be considering an exit from the country, but said its decision was because of high pricing.

Set to be India’s biggest auction ever, the contest could raise as much as INR5.6 billion ($83 billion) in line with the reserve price set, but the government has since moved to dampen forecasts.

It is offering 2.354.55MHz of spectrum in seven bands – 700MHz, 800MHz, 900MHz, 1800MHz, 2100MHz, 2300MHz and 2500MHz.

Both Vodafone India and Idea Cellular are tipped to bid aggressively in the auction to boost their 4G presence.

Economic Times reported the companies only have 4G airwaves in about half of the country’s 22 circles, while rivals Airtel and Jio are better placed to support 4G services.

Vodafone Group reportedly plans to inject as much as $3 billion equity into its Indian operations, in preparation for the auction next month and increased competition from Reliance Jio.

Telecoms minister Manoj Sinha said he expects operators to bid in the auction to address coverage gaps, added ET, but refused to comment on how much the auction will generate.