MRPL had a net loss of Rs 951 crore in the same period a year ago.
Turnover was lower at Rs 12,488 crore in July-September this fiscal as compared to Rs 16,770 crore in the same period a year ago.
It processed 3.46 million tons of crude oil in the second quarter, almost unchanged from previous year.
MRPL earned 34 cents on turning every barrel of crude oil into fuel in the quarter as compared to a negative gross refining margin of USD 4.04 per barrel in the second quarter of previous fiscal.
The profit was "severely dented due to depreciation of rupee against US dollar during the quarter by 3.05 per cent," the statement said.