The shares were last traded at Rs 19.75, down by 5.73 per cent.
As many as 19 cases of alleged corruption and irregularities in the projects of state-run NHPC have been reported, Parliament was informed on Thursday.
"These cases, which pertain to the construction work of various projects of NHPC, have been reported during the years 2010, 2011 and 2012, " Power Minister Jyotiraditya Scindia said in a reply to the Lok Sabha.
He said the records of action taken on these allegations are in accordance with the instructions of the Central Vigilance Commission and other departments.
Investigations are on in the cases, and in certain cases reports have also been filed.