India’s plan to privatise Bharat Petroleum Corp. has run into rough weather with bidders struggling to find partners and spread their financial risks, according to people familiar with the matter. The three suitors -- the Vedanta group, Apollo Global Management and I Squared Capital -- are talking to global energy giants and sovereign and pension funds, but haven’t been able to finalize partners, the people said, asking not to be identified as the deliberations are private. Some bidders are finding it difficult to invest due to sustainability rules that make it tougher for them to buy a stake in an oil refiner, some of the people said. The fresh hurdle to sell the government’s entire stake could temper some of the euphoria generated by the recent sale of Air India Ltd. to the Tata Group and slow down the nation’s biggest privatisation drive. The sale of the state-run refiner-cum-fuel retailer would have fetched about $13 billion for the exchequer and other shareholders.