Even as Sensex and Nifty were dragged lower for the third consecutive session on Tuesday, shares of PSU oil marketing companies like\u00a0Bharat Petroleum Corp Ltd (BPCL), Hindustan Petroleum Corp Ltd (HPCL), and Indian Oil Corporation (IOC) reversed their morning losses to end flat following a slide in crude oil prices.\u00a0Shares of major oil marketing companies shrug off their losses after Brent crude slipped nearly 1.83% to $78.37\/bbl in the global market. HPCL shares, which dipped nearly 4% to an intra-day low of Rs 201.80 on the BSE in early morning trade, ended 3.31% higher, reversing nearly all of its day's losses. IOC shares ended 0.12% higher, while BPCL shares ended marginally lower by 0.79% after falling nearly 3.8% intra-day. In early morning trade, oil marketing companies were the worst drag on the BSE energy index and were among the major contributors to the fall in the benchmark indices. Also read:\u00a0Share market HIGHLIGHTS: Sensex extends losses for 3rd straight day, Nifty ends below 10,150 as IT, pharma stocks drag Oil marketing companies shares took a knock on Tuesday after\u00a0Japanese brokerage firm\u00a0Nomura downgraded the three PSU oil companies\u00a0citing concerns over confidence on marketing reforms. Shares of BPCL, HPCL and IOC fell up to 4% on the domestic bourses following the downgrade from 'buy' to 'neutral'. According to Nomura, the government's India govt's decision to ask OMCs to absorb 1 rupee per litre on petrol\/diesel is a big dent to the confidence on marketing reforms, and\u00a0with elections in 2019 and weak macros, investor confidence may not recover any time soon.\u00a0Nomura believes OMCs are making losses on petrol currently that will unlikely be made good, as officially the fuel prices remain deregulated. The Japanese brokerage also cut its earnings forecasts for FY19 by 11-18% and acknowledged "earnings cuts are sharp and confidence is lower." However, GAIL India and Reliance Industries remained Nomura's preferred picks in the oil and gas sector. Despite the oil companies shares losing after the downgrade, the PSU oil companies' shares reversed their losses during the last hour of trade on Tuesday after\u00a0oil prices slipped below the $79\/bbl-mark on Saudi Arabia's reassurance ahead of US sanctions on Iran's crude exports that start next month. According to a Reuters report, Saudi Arabia reassured investors that it could supply more crude\u00a0oil at a faster pace. Benchmark Brent crude oil fell $1.51 a barrel to a low of $78.32, down 1.9% and below its 50-day moving average for the first time in two months, before recovering a little to around $78.35.