Mumbai, Aug 19 - A key index of Indian equities markets dipped sharply a little before noon Wednesday, almost reversing the previous day's gains.

At 11.30 a.m., the 30-scrip benchmark index of the Bombay Stock Exchange (BSE), the Sensex, which opened slightly higher at 14,079.04 points, fell sharply to 14,811.54 points -- 223.72 points or 1.49 percent lower than Tuesday's close.

At around the same time, the S&P CNX Nifty of the National Stock Exchange (NSE) was trading in the negative terrain at 4,395 points, down 1.43 percent.

Broader market indices also came under selling pressure, with the BSE midcap index trading 0.76 percent lower and the BSE smallcap index moving down 0.16 percent.

All the 13 sectoral indices on the BSE were in the red, with those for auto, energy and banking stocks losing the most.

The market breadth was negative, with 998 stocks on the rise, compared to 1,190 on the decline, while 72 remained unchanged.