Snapping four days of losses, the Sensex at the Bombay Stock Exchange rose a modest 54 points, or 0.3 percent, to 17,560, as investors bought blue-chips at attractive lower levels, today. The Sensex had lost more than 800 points in the past four trading sessions. The Nifty at the National Stock Exchange rose 18 points, or 0.3 percent, to 5,276.Stock markets inJapan, China, Hong Kong, South Korea and Singapore rose between 1 percent and 1.5 percent.