The Sensex at the Bombay Stock Exchange slumped 299 points, or 1.7 percent, to again close below the 17,000 mark, at 16,867, on heavy profit-booking by investors, amid falling global markets, today. The Nifty at the National Stock Exchange lost 94 points, or 1.8 percent, to 5,059.Stock markets in Japan, China, Hong Kong, Singapore, and South Korea lost between 0.1 percent and 1.8 percent, on fresh worries about global economic growth.