Tata Sons wrote off Rs 28,651 crore on its telecom business in the previous financial year, Economic Times reported.
Tata Sons, the holding company for the Tata group, agreed to sell the mobile service business of Tata Teleservices (TTSL) to Bharti Airtel. Airtel is leading the consolidation drive in the Indian telecom market by acquiring assets from TTSL, Videocon and Telenor Group.

Tata Sons posted 14 percent increase in total revenue to Rs 1,96,903 crore in the year ended March 2018 from Rs 1,73,178 crore in the previous year.

Profit after tax declined to Rs 4,379 crore from Rs 18,432 crore, after exceptional items worth Rs 21,216.2 crore, compared with Rs 7,352.7 crore a year ago, Tata Sons said in filings with the Registrar of Companies.