Shares of Bharat Petroleum Corporation gained 4.05 per cent on the BSE after UBS upgraded the stock to "buy" from "neutral".
UBS said BPCL has the best marketing and refinery operations, the least debt, and offers superior ROE.
It added that the diesel-price deregulation has given rise to too much optimism.
UBS reiterated "neutral" on Indian Oil Corp and "sell" on Hindustan Petroleum Corporation.
At 11.30 am, the BPCL stock was up 4.05 per cent or Rs 32.25 at Rs 828.15 on the BSE.