Tata Teleservices, one of the smallest mobile operators in India, is preparing to shut down its operations with the heads of its regional units told to leave by the end of March 2018, The Economic Times (ET) said.

Company executives of Tata Sons, the parent company of Tata Teleservices, are holding talks with the Department of Telecommunications about offloading its spectrum holdings after informing the government of plans to close the business. It is expected to try to sell spectrum awarded through auctions to pay down its debt, but it will have to return any spectrum allocated administratively by the government.

The operator holds debt of INR300 billion ($4.59 billion), ET reported. It had 42 million mobile subscribers at end-September, giving it a 3.5 per cent market share.

A source told ET few of the operator’s 5,000 employees will be transferred to other Tata Group companies. The company reportedly already stopped accepting new subscribers in several regions.

Tata Teleservices, which was set up in 1996 as a fixed-line operator, received INR140 billion in funding from NTT Docomo in 2008, but the Japanese operator pulled out of the loss-making joint venture in 2014.

Attempts by Tata Sons to find new partners were not successful.