BPCL's stock dived 4.47 per cent to settle at Rs 729.15 on the BSE. During the day, it slipped 5 pet cent to Rs 725.05.
On the NSE, it tumbled 5.23 per cent to end at Rs 725.30.
Tracking weakness in the stock, the company's market capitalisation fell by Rs 2,469.31 crore to Rs 52,723.69 crore.
In terms of volume, 2.31 lakh shares of the company changed hands at the BSE, while more than 22 lakh shares were traded at the NSE during the day.
Net profit in the July-September period at Rs 464.20 crore, or Rs 6.42 per share, was 50 per cent lower than Rs 931.13 crore, or Rs 12.88 a share, in the same period a year ago, the company had said in a filing to the stock exchanges.
The company earned USD 2.36 on turning every barrel of crude oil into product as opposed to a gross refining margin of USD 4.38 per barrel last year.
