Telecom stocks tumbled up to 6.5 per cent on Wednesday after Reliance Jio decided to offer extra data on some plans, intensifying the tariff war in the sector. Shares of Bharti Airtel tanked 6.51 per cent to end at Rs 458.95 on BSE. The stock was the worst performer among the 30-Sensex scrips. Idea Cellular plunged 5.38 per cent to Rs 94.05 and Reliance Communications slipped 1.37 per cent to Rs 28.80. Idea shares were also under pressure amid earnings disappointment. Idea Cellular on day posted deeper losses of Rs 1,284.5 crore for the quarter ended December 31, 2017.