Meanwhile, the BSE Sensex was up 181.27 points, or 0.61%, to 29,757.01.

Shares of Tata Power Company dropped 2.99% to Rs 84.50. The stock hit high of Rs 90.20 and low of Rs 81.30 so far during the day. On BSE, so far 25.11 lakh shares were traded in the counter, compared with an average volume of 3.47 lakh shares in the past two weeks.

Shares of Adani Power dropped 16.01% to Rs 37.25. The stock hit high of Rs 46.30 and low of Rs 36.55 so far during the day. On BSE, so far 1.16 crore shares were traded in the counter, compared with an average volume of 13.23 lakh shares in the past two weeks.

The Supreme Court (SC) today, 11 April 2017, set aside an earlier Appellate Tribunal for Electricity (Aptel) ruling that allowed Tata Power and Adani Power to charge compensatory tariff from consumers.

A bench comprising justices Pinaki Chandra Ghose and Rohinton F. Nariman ruled in a batch of appeals filed against an April 2016 ruling of Aptel which held that an unforeseen increase in the cost of coal would be a “force majeure event” under the power purchase agreements (PPAs) between power generating companies and distributors. SC said higher tariffs could be allowed only if there was a change in Indian laws.

The companies had cited a change in Indonesian regulations in 2010 as a force majeure event that increased the cost of coal imported by Tata Power and Adani Power from that country to fuel their electricity plants.

Tata Power's wholly-owned subsidiary Coastal Gujarat Power (CGPL) and Adani Power's Mundra project in Gujarat have PPAs with state discoms in Rajasthan, Gujarat, Haryana and Punjab. Both generating plants are fueled by coal imported from Indonesia.

On a consolidated basis, Adani Power reported net loss of Rs 323.61 crore in Q3 December 2016, compared with the net profit of Rs 109.49 crore in Q3 December 2015. Net sales declined 6.15% to Rs 5803.52 crore in Q3 December 2016 over Q3 December 2015.

Adani Power is the largest private thermal power producer in India with an installed capacity of 10,480 MW.

On a consolidated basis, net profit of Tata Power Company rose 38.30% to Rs 599.20 crore on 8.68% decline in net sales to Rs 6677.89 crore in Q3 December 2016 over Q3 December 2015.

Tata Power is India's largest integrated power company with a significant international presence. The company has a presence in all the segments of the power sector viz generation (thermal, hydro, solar and wind), transmission, distribution and trading.