Mumbai, Aug 7 - A key index of the Indian equities markets opened in the red Friday and was 51 points down about 15 minutes into trade.

The sensitive index (Sensex) of the Bombay Stock Exchange (BSE) opened lower at 15,440.95 points, as against Thursday's close at 15,514.03 points. After 15 minutes, it was at 15,462.34 points, 51.69 or 0.33 percent down from its previous close.

The broader S&P CNX Nifty of the National Stock Exchange (NSE) too was in the red and was at 4,565.15 points, a fall of 0.44 percent.

Broader market indices were trading mixed, with the BSE midcap index ruling 0.21 percent down, and the BSE smallcap index up 0.11 percent.