Rising for the third straight session, the Sensex at the Bombay Stock Exchange gained a good 226 points, or 1.3 percent, to 17,814, today, as indications of higher advance tax payout by corporates, and firm global markets boosted investor sentiment. The 30-share Sensex had climbed more than 440 points in the previous two trading sessions. The Nifty at the National Stock Exchange rose 70 points, or 1.3 percent, to 5,430.Stock markets in Japan, China, Hong Kong, South Korea and Singapore added between 0.1 percent and 1 percent.