The Sensex at the Bombay Stock Exchange dropped 238 points, or 1.4 percent, to 17,095, on heavy selling in IT stocks, after disappointing quarterly results from industry bellwether, Infosys, and amid weak European markets, today. The Nifty at the National Stock Exchange slipped 69 points, or 1.3 percent, to 5,207. But stock markets in Japan, China, Hong Kong, South Korea and Singapore rose between 0.3 percent and 1.8 percent.