Indian main stock index Sensex opened at 16,812.30 points Monday, 34.53 points or 0.2 percent lower from previous close of 16,846.83 on profit taking. Metal, banking, oil and gas and IT sector dipped 0.85 percent, 0.82 percent, 0.5 percent and 0.35 percent, respectively. Aluminum refiner Hindalco, Tata Steel, copper maker Sterlite Industries and ICICI Bank dropped 2.37 percent, 2.11 percent, 1.96 percent and 1.75 percent. Still, telecom operator Bharti Airtel, property developer Jaiprakash Associates, DLF and automobile maker Mahindra and Mahindra gained 1.24 percent, 0.97 percent, 0.87 percent and 0.7 percent. Sensex is the common name for the Bombay Stock Exchange Sensitive Index. It consists of the 30 largest and most actively traded stocks, representative of various sectors, on the Bombay Stock Exchange.