The Sensex at the Bombay Stock Exchange fell 172 points, or 1 per cent, to 17,529, in opening trade, today, amid weak global markets. Remaining subdued, the Sensex stood 187 points, or 1.1 percent in the red, at 17,514, a short while ago. Global markets also lost ground, after Chinese manufacturing growth slowed, and Moody's Investors Service placed Spain's credit rating on review for a possible downgrade, fueling concern over the strength of the global economy. So the Asian bourses in Japan, China, Taiwan, South Korea, Singapore and Indonesia lost between 0.5 percent and 2 percent, today. The US Dow Jones Industrial average had ended almost one per cent lower, overnight.