Sensex and Nifty, the two key equity benchmarks, on Friday opened in the red, falling for the third day amid an overall bearish trend in global markets.


At 10.45 am, the BSE Sensex tanked 653 points to 58,466, while the broader NSE Nifty dropped by 202 points to 17,427.


Among the 30-share Sensex platform, Power Grid, IndusInd Bank, HDFC, Mahindra & Mahindra, and Axis Bank were the major laggards in early trade. On the flip side, Tata Steel, Hindustan Unilever, Sun Pharma, Infosys, HCL Technologies, and Dr Reddy's were the gainers.


In the broader markets, Nifty SmallCap 100 and Nifty MidCap 100 indices slumped over 0.2 per cent.


All sectors traded on a volatile note. While Nifty Media, Nifty Pharma, Nifty Metal indices opened with marginal gains; Nifty Bank, Nifty Realty, Nifty Energy indices slipped the most, nearly 1 per cent.


"The global risk-off is gaining strength aided by the steadily rising dollar. Dollar is rising against all currencies and this will impact capital flows into emerging markets including India. Resumption of FPI buying since July has been supporting the rally in India. Now this is under threat with FPIs turning sellers in 5 out of the last 7 days," said V K Vijayakumar, chief investment strategist, Geojit Financial Services. The near-term market outlook is bearish, Vijayakumar added.


In the previous session on Thursday, the BSE benchmark had declined 337 points (0.57 per cent) to settle at 59,119, while the Nifty dipped 88 points (0.50 per cent) to end at 17,629.


Elsewhere in Asia, markets in Seoul, Tokyo, Shanghai and Hong Kong were trading lower. The US markets ended in the negative territory on Thursday.


The international oil benchmark Brent crude declined 0.50 per cent to $90.02 per barrel.


Foreign institutional investors (FIIs) offloaded shares worth a net Rs 2,509.55 crore on Thursday, according to data available with the BSE.


Meanwhile, the rupee depreciated 44 paise and slipped below the 81-mark against the US dollar for the first time in early trade on Friday, weighed down by the strong US currency and risk-off sentiment among investors. The rupee opened at 81.08 against the greenback, then fell further to 81.23, registering a fall of 44 paise over its previous closing.