The Sensex at the Bombay stock Exchange tumbled 334 points, or 2 per cent, to 16,154 in opening trade, on Friday morning. Later the Sensex remained weak, and stood 316 points, or 1.9 percent in the negative zone, at 16,172, in afternoon deals, a short while ago. The Sensex fell on concerns about slowing industrial growth, and as regional markets declined on receding hopes for a speedy resolution to the euro zone's debt crisis. Other Asian bourses in Japan, China, Hong Kong, Indonesia, Singapore, South Korea and Taiwan were down by between 0.7 percent and 2.4 percent, today, after after the Europan Central bank damped speculation that it would step up debt purchases, and a European Union summit disappointed. Across in the US, the Dow Jones Industrial Average had slipped 1.6 per cent, overnight.