However, shares of consumer durable and healthcare sectors firmed up on good buying enquiries.
The BSE-30 share index Sensex resumed lower at 20,479.03, and hovered in a range of 20,480.35 to 20,391.96 before quoting 20,439.95 points at 1030 hours.
It showed a loss of 73.90 points or 0.36 per cent from its last weekend's close.
The NSE Nifty also moved down by 23.80 points, or 0.39 per cent, to 6,065.70 at 1030 hours.
Major losers were - Hindalco Industries 2.60 pct, Bharti Airtel 2.21 pct, Mahindra & Mahindra 2.21 pct, Tata Steel 1.87 pct, Tata Motors 1.83 pct, ICICI Bank 1.25 pct and Oil & Natural Gas Corpn 1.23 pct.
Foreign institutional investors (FIIs) sold shares worth a net Rs 652.97 crore on last Friday, as per provisional data from the stock exchanges.
Asian stocks fell in their early trade after a slowdown in Chinese manufacturing growth added to concern that the global economic recovery is faltering.
Key benchmark indices in Indonesia, Japan, Singapore and South Korea shed by 0.7 to 1.41 per cent.
US stocks fell sharply on Friday amid continued unease over emerging markets and a number of high-profile earnings disappointments.