The Sensex at the Bombay Stock Exchange fell 40 points, or 0.2 per cent, to 17,661, in early trade on Thursday, on profit-booking. Falling further, the Sensex stood 103 points, or 0.6 percent in the red, at 17,598, a short while ago. Stock markets in China, Japan, South Korea, Singapore, Hong Kong, Taiwan and Indonesia were down by between 1 percent and 1.3 percent on profit-booking, after recent strong gains.