The company posted a net profit of Rs 450.24 crore, or Rs 5.67 per share, in April-June compared with Rs 494.41 crore, or Rs 6.17 per share, in the same period of the previous fiscal.
"The reduction in profit after tax (net profit) was primarily due to the reduction in price of natural gas from USD 3.06 per million British thermal unit in Q1 FY 2016-17 to USD 2.48 per mmBtu in Q1 FY 2017-18," Oil India said in a statement.
Oil production rose 5.6 per cent to 0.848 million tons in April-June, for which it got USD 48.41 per barrel as against USD 43.09 in Q1 of the previous year.
During the quarter, OIL completed buy back of its 4.49 crore shares, representing 5.60 per cent of the total paid up equity shares, at an offer price of Rs 340 per share.
"As a result the share capital has decreased to Rs 756.60 crore as on June 30," the statement added.