State-owned explorer Oil and Natural Gas Corp. Ltd (ONGC) signed a deal with the President of India to acquire 51.11% stake in Hindustan Petroleum Corp. Ltd (HPCL), a state-run refiner, for Rs.36,915 cr. ONGC’s acquisition of HPCL will make the explorer a more integrated energy company and is a revenue booster for the government in a fiscally challenged year that saw falling indirect tax revenue and lower dividend receipts from the Reserve Bank of India.