Foreign investment firms, especially private equity, are jittery about the Indian market as uncertainty continues to shroud the energy sector.
Higher power tariff would have fetched Tata's Mundra UMPP Rs 25,000 crore (Rs 250 billion) and Adani's project an additional Rs 18,500 crore (Rs 185 billion)
Auto and index heavyweights Reliance Industries and ITC were the top losers in early trades.
Rates to go up as Delhi power regulator works out plan to liquidate past dues.
The 30-share BSE Sensex closed down 162 points at 28,338 and the 50-share Nifty was down 67 points at 8,463.