A benchmark index of Indian equities markets, the 30-scrip BSE Sensitive Index (Sensex) was trading flat at 23.52 points or 0.09 percent in the afternoon session on Wednesday.The wider 50-scrip Nifty of the National Stock Exchange (NSE) was also trading 23.70 points or 0.28 percent down at 8,315.65 points.The Sensex of the S&P Bombay Stock Exchange (BSE), which opened at 27,447.40 points, was trading at 27,507.89 points (at 2.30 p.m.) down 23.52 points or 0.09 percent from the previous day's close at 27,531.41 points.The Sensex has touched a high of 27,574.88 points and a low of 27,363.72 points in the intra-day trade so far.Heavy selling pressure was seen in auto, information technology and technology media and entertainment (TECK) sectors.