Mumbai, July 29 - A key index of the Indian equities markets opened slightly lower Wednesday, and slid further into the red about five minutes into trade.

The sensitive index (Sensex) of the Bombay Stock Exchange (BSE) opened at 15,293.19 points, as against Tuesday's close at 15,331.94 points, and then moved further down to 15,253.1 points.

The broader S&P CNX Nifty of the National Stock Exchange (NSE) was also ruling in the red at 4,531.9 points, a loss of 0.71 percent.

Broader market indices were almost flat, with the BSE midcap index trading 0.05 percent lower, and the BSE smallcap index up 0.04 percent.