Bharat Petroleum Corp Ltd reported on Friday a 77 per cent plunge in third-quarter net profit, dragged down by higher expenses including raw material costs.Profit came in at Rs 495 crore in the three months ended December 31, compared with Rs 2,144 crore a year earlier, the state-run company said.However, it beat analysts' estimate of a profit of Rs 45.78 crore, according to Refinitiv Eikon data.The state-owned oil companies were forced to take a price cut in October as the government wanted to cushion the impact of high crude oil price on the public.Average gross refining margin (GRM) in the third quarter was $2.78 per barrel, compared with $7.89 per barrel a year earlier, while revenue from operations surged 25.7 per cent to Rs 88,238 crore.