Extending losses for the third straight day, the benchmark BSE Sensex lost over 45 points in early trade on Monday on sustained selling by funds and retailers, amid a weak trend in other Asian markets.

The 30-share barometer, which had lost nearly 226 points in the previous two sessions, fell further by 45.15 points, or 0.21 per cent, to 21,018.47. Realty, banking, oil & gas and capital goods sectors stocks led the fall.

Similarly, the National Stock Exchange index Nifty declined by 9.75 points, or 0.16 per cent, to 6,251.90.

Brokers said sustained selling by funds and retailers amid a weak trend in other Asian markets mainly dampened the trading sentiment here.