The stock plunged 5.62 per cent to Rs 40.30 on BSE.
At NSE, shares of the company slipped 6.43 per cent to Rs 40.
The company's total income stood at Rs 15,213.4 crore, from Rs 15,706.6 crore a year ago, Amtek Auto had said in a BSE filing on Saturday.
For the quarter ended September, the firm reported a standalone net loss of Rs 158.62 crore as against a net profit of Rs 74.37 crore in the same period of the previous fiscal.
Amtek Auto follows October-September financial year.
The Delhi-based company had defaulted on repayment of bonds worth Rs 800 crore in September, thus signaling a crisis.