<p><b>A bird flies by the Vedanta office building in Mumbai</b> <p></p><p> <p>Regulatory hurdles could delay Vedanta Resources' purchase of a stake of up to $9.6 billion in Cairn India, but the buyer and analysts see them as unlikely to derail the deal. <p></p><p> <p>Vedanta, in its first move into the energy sector, is buying a controlling stake in India's 4th largest oil and gas company from Britain's Cairn Energy to capitalise on rising energy demand, economic growth and an expanding population. <p></p><p> <p>The deal will need the Indian government's approval because Cairn India has production-sharing contracts (PSCs) with the government for its oil and gas exploration blocks. According to their agreement, any change of ownership would require the government approval. <p></p><p> <p>Approval from state-run explorer ONGC, which has a 30 per cent stake in Cairn India's Rajasthan oil block called RJ-ON-90/1, is also crucial for any change of ownership at British firm's Indian unit. <p></p><p> <p>ONGC has not yet raised concerns on the Cairn India-Vedanta deal, Indian Oil Secretary S Sundareshan said on Tuesday, adding the government would take into account ONGC's views on the deal. <p></p><p> <p>Cairn Energy Chairman Bill Gammell arrived in New Delhi late Monday to speak with government officials in hopes of ironing out the approval process for the acquisition. <p></p><p> <p><b>(Pictures by Reuters)</b> <p></p>