Mumbai, Aug 6 - A key index of the Indian equities markets was ruling in the red Thursday after a weak start and shortly before noon was 81 points lower than its previous close.

At 11.30 a.m., the 30-scrip benchmark index of the Bombay Stock Exchange (BSE), the Sensex, which opened lower at 15,881.47 points, was at 15,822.66 points -- 81.17 points or 0.51 percent lower than Wednesday's close.

At around the same time, the S&P CNX Nifty of the National Stock Exchange (NSE), too, was trading in the red at 4,674.2 points, down 0.42 percent.

However, broader market indices were trading in the green, with the BSE midcap index trading 0.22 percent higher and the BSE smallcap index moving up 0.80 percent.

On the BSE, consumer durables, auto and IT stocks came under selling pressure, while healthcare and PSU stocks found favour among buyers.

The market breadth was tilted towards the positive, with 1,315 stocks rising, compared to 953 declining on the BSE and 83 remaining unchanged.