The Sensex at the Bombay Stock Exchange, which had opened 86 points lower, this morning, later lost further ground, and stood 138 points, or 0.7 per cent in the red, at 20,084, a short while ago. Continued profit-booking, off-loading of positions by participants ahead of tomorrow's monthly expiry in the derivatives segment, and weak Asian and European bourses dragged the domestic market lower. Other Asian markets in Japan, Hong Kong, South Korea, Singapore and Taiwan were down by between 0.5 percent and 1 percent.