Snapping two days of gains, the Sensex at the Bombay Stock Exchange fell 101 points, or 0.6 percent, to 18,394 on Wednesday on profit-booking by investors, and in tandem with weak global markets. The Nifty at the National Stock Exchange dropped 29 points, 0.5 percent, to 5,527.Stock markets in Japan, China, Hong Kong, South Korea and Singapore were largely subdued, on concerns about the slowing US economic recovery.