The Sensex at the Bombay Stock Exchange fell 23 points, or 0.1 per cent, to 19,982 in early trade, today, ahead of the monthly expiry in the derivatives segment. Later, the Sensex lost some more ground, and stood 81 points, or 0.4 percent in the red, at 19,925 in afternoon deals, a short while ago.Key stock indices in Japan, China, Indonesia, Taiwan, South Korea, Hong Kong and Singapore had gained between 0.3 percent and 2.3 percent, today. But the US Dow Jones Industrial Average had ended 0.3 per cent lower in yesterday's trade, after data showed that the US economy unexpectedly shrank in the last quarter of 2012.