The Sensex at the Bombay Stock Exchange gained 135 points, or 0.8 percent, to 18,289 today, on renewed buying by funds, in line with rising global markets. The Nifty at the National Stock Exchange rose 42 points, or 0.8 percent, to 5,564. Stock markets in Japan, Hong Kong, Singapore and South Korea climbed between 0.8 percent and 1.6 percent, on robust US economic data.