The Sensex at the Bombay stock Exchange rose 89 points, or 0.5 per cent, to 17,488 in opening trade, this morning, on fresh buying by funds and retail investors, amid rising Asian markets. Later, the Sensex remained firm, and stood 72 points, or 0.4 percent in the green, at 17,471 in afternoon trade, a short while ago.Key stock indices in Japan, Hong Kong, Indonesia, South Korea, Singapore and Taiwan were up by between 0.7 percent and 1.2 percent.