Erasing initial gains, the Bombay Stock Exchange Sensex was down by 101 points at 17,885 points when reports last came in. The Sensex, which had gained nearly 79 points in opening trade, after a while fell by over 82 points, after stocks of technology, oil and gas, capital goods and auto companies succumbed to profit-booking. The broad-based National Stock Exchange Nifty index was also trading in red at 5,369, down by 28 points.