Mumbai, Aug 27 - After a choppy start Thursday, a key Indian equities index ended higher for the sixth straight trading day, even as the session was marked by high volatility due to profit taking and weak global cues, especially in other Asian markets.

The sensitive index (Sensex) of the Bombay Stock Exchange (BSE) ended at 15,781.07 points, over the previous close at 15,769.85 points, to log a marginal gain of 11.22 points, or 0.07 percent.

Within the Sensex, the losers and the gainers were equally matched at 15 stocks each, with Bharti Airtel leading the stocks that ended higher, and Tata Steel emerging as the top loser.

Three sector-specific indices of the exchange - those for metals, banking and realty stocks - ended in the red, while all the remaining 10 ended higher, led by the index for consumer goods.

At the National Stock Exchange (NSE), however, the broader S&P CNX Nifty closed at 4,688.2 points, against the previous close at 4,680.85 points, with a marginal gain of 0.16 percent, data with the exchange showed.