Snapping a four session winning streak, the Sensex at the Bombay Stock Exchange fell 241 points, or 1.4 per cent, to 17,337 in opening trade, today, after the Reserve Bank of India last week unexpectedly raised its key short-term lending and borrowing rates. Recovering partially, the Sensex stood 83 points, or 0.5 percent in the red ,at 17,496, a short while ago. Stock markets in Hong Kong, Indonesia, South Korea, Singapore and Taiwan were down by between 0.2 percent and 1.5 percent.