The power utility's scrip ended the day 14.76 per cent lower at Rs 71.35 on the BSE. During the day, the stock had plunged 18.45 per cent to Rs 68.25 -- its 52-week low.
At the NSE, the scrip nosedived 14.35 per cent to close the day at Rs 71.95.
The blue-chip stock was the worst performer on both the key indices -- Sensex and Nifty.
Following the slump in the share price, the market value of the company fell by Rs 2,931 crore to Rs 16,931 crore.
Tata Power today reported a consolidated loss of Rs 114.70 crore in the three months ended June, hurt by weakening rupee and higher financing costs related to Mundra project.
The country's leading power utility had a consolidated net profit of Rs 145.93 crore in the year-ago period.
These figures are after tax, minority interest and share of profit/(loss) of associates.
In a regulatory filing, the company said its total income in the first quarter of current fiscal jumped to Rs 9,111.57 crore from Rs 7,316.47 crore.
However, on a standalone basis, the power producer saw its net profit after tax rise to Rs 357 crore for the June quarter.
The company's total income climbed to Rs 2,787.39 crore in the first quarter of current financial year.
Meanwhile, the broader market was also weak, with the BSE benchmark Sensex ending the day 2.34 per cent or 449.22 points lower at 18,733.04.