Indian Oil Corporation (IOC) has reported a 40% surge in its fourth-quarter profit, owing to higher refinery margin and inventory gains. IOCs total income rose during the quarter by 10 per cent to Rs 136,980 crore from Rs 124,405 crore in the corresponding quarter, as stated in its Bombay Stock Exchange (BSE) filing. This comes against the backdrop of diesel and petrol prices reaching all-time highs in the international market.