Equity benchmark Sensex dropped over 200 points in opening trade on Thursday tracking losses in index majors TCS, ICICI Bank and HDFC Bank amid weak cues from global markets. The 30-share BSE index was trading 248.36 points or 0.61% lower at 40,546.38, and the broader NSE Nifty fell 62.05 points or 0.52% to 11,909. Tech Mahindra was the top loser in the Sensex pack, shedding around 2%, followed by HCL Tech, TCS, ICICI Bank, Bajaj Finance and ITC. On the other hand, Tata Steel, ONGC, NTPC, Asian Paints, M&M, Nestle India and Bharti Airtel were among the gainers. In the previous session, Sensex ended at 40,794.74, up 169.23 points or 0.42%, while the broader Nifty rose 36.55 points or 0.31% to 11,971.05. Exchange data showed that foreign institutional investors bought equities worth ₹821.86 crore on a net basis on Wednesday. According to traders, weak cues from global markets led domestic benchmark indices lower. Bourses in Shanghai, Hong Kong, Tokyo and Seoul were trading on a negative note in mid-session deals. Stock exchanges in the U.S. too ended in the red in overnight session amid uncertainty over U.S. economic stimulus. Meanwhile, international oil benchmark Brent crude was trading 0.16% higher at USD 43.39 per barrel.