New Delhi, Mar 29 (IANS): India's key equity indices -- Sensex and Nifty -- extended their gains from the previous to rise marginally in the opening session on Tuesday.

Strong global cues and retreating crude oil prices buoyed the Indian indices.

At 9.56 a.m., Sensex was 0.5 per cent or 272 points up at 57,865 points, whereas Nifty 0.5 per cent or 79 points up at 17,301 points.

"Stability in global markets, softening crude and chances of a ceasefire in Ukraine can provide the positive backdrop for this breakout," said V.K. Vijayakumar, Chief Investment Strategist at Geojit Financial Services.

However, high US inflation and an increasingly hawkish US Fed are major headwinds for equity markets globally, said Vijayakumar, adding that he expects volatility in the markets.

Adani Ports, Divi's Labs, Ultratech Cement, Bharti Airtel, and Cipla were the top five gainers among the Nifty 50 companies, while ONGC, Coal India, Hindalco, ITC, and Tata Steel the top five losers.