The broader NSE Nifty 50 index slipped 0.2% to 11,131.85 and the S&P BSE Sensex fell 0.17% to 37,668.42. Both the indexes have shed more than 3% so far this week.
Shares of telecom operator Bharti Airtel Ltd fell as much as 10% to their lowest since April 3, after rival Jio, the telecom unit of Reliance Industries, rolled out new postpaid plans on Tuesday bundled with video-streaming services.
TCS fell as much as 4.5% after, Shapoorji Pallonji (SP) group, the largest minority shareholder in Tata Group, said on Tuesday it wanted to separate interests from the autos-to-steel conglomerate.
"Tatas have to make some back to back arrangements for raising money if they are parting ways with Shapoorji Pallonji and investors may be asked to contribute directly or indirectly," said Deepak Jasani, head of research, HDFC Securities.
Meanwhile, India's coronavirus infections surged again on Wednesday. Britain re-imposed some lockdown measures as a second wave of coronavirus infections sweeps across Europe, while the death toll in the United States crossed 200,000.
"As the fresh covid cases are rising day by day ... it is increasing tension among retailers as well as big players in the market," said Rahul Sharma, head of research, Equity99 Advisors in Mumbai.
Both the benchmark indexes had earlier risen nearly 1%, boosted mainly by Reliance that rose as much as 3%, after it said U.S. private equity firm KKR would invest 55.50 billion rupees ($755.09 million) in the conglomerate's retail arm.
By Sethuraman N R