BENGALURU, May 27 (Reuters) - Indian blue-chip indexes hit record highs at the open on Monday before easing back as energy stocks dropped and as volatility remained high due to nerves over the results of the ongoing general elections.

The NSE Nifty 50 was up 0.2% at 22,991.05 points as of 10:38 a.m. IST, while the S&P BSE Sensex added 0.24% to 75,588 points.

They had risen about 0.4% near the open to hit record highs for a third straight session in a row.

But, like in previous sessions, volatility remained elevated as reports of lower voter turnout in the elections and voter fatigue fan doubts about the margin of victory for the ruling party when the results are announced on June 4.

The volatility index has surged almost 78% so far this month, including climbing 5% on the day.

"This would be last week where we await the outcome of the national general elections so volatility will continue to remain at elevated levels ... due to nervousness about the outcome," said Siddhartha Khemka, head of retail research at Motilal Oswal Financial Services.

Moreover, it is the last leg of earnings and that would also be an important factor this week, Khemka added.

Life Insurance Corp and National Aluminium Co among the companies reporting results, on the day.

Banks and heavyweight financials were the top sectoral gainers, up 0.7% each on the day. Energy stocks , however, dropped 0.8%.

Divi's Labs advanced 4.2%, leading gains on the Nifty 50, after posting strong quarterly results.

Adani Ports rose 1.5% while Wipro dropped 1.6% on news that Adani Ports will replace Wipro in the 30-stock Sensex, effective June 24. (Reporting by Dimpal Gulwani and Manvi Pant in Bengaluru; Editing by Savio D'Souza)