Equity benchmark Sensex surged over 800 points in opening trade on Wednesday as hopes of a resolution in Russia-Ukraine talks boosted market sentiment amid a positive trend in global markets.

The 30-share Sensex was trading 808.69 points or 1.45 per cent higher at 56,585.54, and the broader Nifty advanced 233.20 points or 1.4 per cent to 16,896.20.

HDFC was the top gainer in the Sensex pack, climbing 3.35 per cent, followed by Axis Bank, IndusInd Bank, Bajaj Finserv, HDFC Bank, ICICI Bank and Bajaj Finance.

On the other hand, Sun Pharma was the only loser in the lot, shedding 0.41 per cent.

In the previous session, the index tanked 709.17 points or 1.26 per cent to finish at 55,776.85. Similarly, the NSE Nifty fell 208.30 points or 1.23 per cent to 16,663.

Meanwhile, Ukraine said there is a possible room for compromise in talks with Russia. After officials from Ukraine and Russia held a meeting on Tuesday via video conferencing, Ukrainian President Volodymyr Zelensky on Wednesday said Russia's demands were becoming more realistic.

Both the countries are likely to hold talks again on Wednesday.

Bourses in Hong Kong, Seoul and Tokyo were trading higher, while Shanghai was in the red in mid-session deals.

Stock exchanges in the US closed with significant gains in the overnight session.

International oil benchmark Brent crude surged 1.38 per cent to USD 101.29 per barrel.

Foreign institutional investors continued their selling spree in Indian markets as they offloaded shares worth Rs 1,249.74 crore on a net basis on Tuesday, as per exchange data.