The 30-share index resumed lower at 21,079.27 points, later rose to 21,140.00 on buying in banks and realty sector stocks and was trading at 21,108.61, lower by 11.51 points, or 0.05 per cent, at 1040 hours.
The NSE Nifty was also trading flat by 1.70 points, or 0.03 per cent higher, at 6,275.25 during the period.
Major losers were Dr Reddy's (1.64 per cent), L&T (1.51 per cent), ONGC (1.27 per cent), Bajaj Auto (1.23 per cent) and SSTL (1.18 per cent).
Key benchmark indices in Hong Kong, Singapore, China, Japan and South Korea fell by 0.71-1.75 per cent.