The BSE benchmark Sensex erased early gains and plunged by 152 points in the first hour of the trading on Friday, as funds and retail investors indulged in booking profits in heavy-weight stocks.

The 30-share index, which opened at over 80 points, fell by 152.31 points to 20,345.33 at 1000 hrs, following weakness in IT, banking and capital goods sector counters.

The broad-based National Stock Exchange index Nifty, too, moved down by 50.55 points or 0.82 per cent to 6,126.80 points after regaining 6,200 points in the opening trade.

Brokers said profit-booking at prevailing prices by participants amid weak trend on other Asian bourses dragged the Sensex down.

Besides, share price of IT major Infosys Technologies had also tumbled by 1.35 per cent to Rs 3,141.20 in the first hour of trade. This was in contrast to its opening at Rs 3,249 on the back of impressive 13.15 per cent consolidated net profit growth for the second quarter, ending September 30.