The Indian main stock index Sensex opened at 16,819.74 points Thursday, 57.32 points or 0.34 percent lower from the previous close of 16,877.06 on reported contraction of industrial output in October. Capital goods, power, metal and oil and gas sectors dipped 0.89 percent, 0.75 percent, 0.73 percent and 0.63 percent, respectively. Coal India, telecom operator Bharti Airtel, aluminum refiner Hindalco and copper maker Sterlite Industries lost 1.62 percent, 1. 59 percent, 1.42 percent and 1.41 percent. Still, Hero Motors, software outsourcing player WIPRO, Bajaj Auto and consumer goods maker ITC gained 1.44 percent, 0.81 percent, 0.53 percent and 0.39 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.