Snapping a six-session losing streak, the Sensex at the Bombay Stock Exchange rallied 273 points, or 1.6 percent, to again close above the 17,000 level, at 17,131 on Wednesday. The Sensex rose on value-buying by investors, amid rising global markets, after the US central bank pledged to keep interest rates near zero for at least two years. The Nifty at the National Stock Exchange climbed 88 points, or 1.7 percent, to 5,161.The bourses in Japan, China Hong Kong and South Korea rose between 0.3 percent and 2.3 percent.