The Sensex at the Bombay Stock Exchange lost 68 points, or 0.4 percent, to 18,220, on profit-booking, and amid weak global markets, today. The Nifty at the National Stock Exchange fell 25 points, or 0.5 percent, to 5,461. Stock markets in Japan, China, Singapore, Hong Kong and South Korea lost between 0.2 percent and 3 percent, on weaker-than-expected Chinese import data.