Mumbai, Feb 3 (IANS): A benchmark index of Indian equities markets plunged by 105.31 points or 0.51 percent in the pre-noon trade Monday.

Selling pressure was seen in the metal, banking index (bankex) and auto sectors, while some good buying was observed in the healthcare sector.

The 30-scrip sensitive index (Sensex) of the S&P Bombay Stock Exchange (BSE), which opened at 20,479.03 points, was trading at 20,408.54 points in the pre-noon session, down 105.31 points or 0.51 percent from the previous day's close at 20,513.85 points.

The Sensex touched a high of 20,480.35 points and a low of 20,391.96 points during the trade so far.

The S&P BSE metal index plummeted by 152.16 points, auto index dropped by 81.28 points and bankex went down by 54.33 points. However, healthcare index gained 82.76 points.

The wider 50-scrip Nifty of the National Stock Exchange (NSE) was also trading down by 31.65 points or 0.52 percent at 6,057.85 points.