At the NSE, it tumbled 8.45 per cent to Rs 132.10.
His statement assumes significance in the light of scams in the state-owned banks.
The posts of Chairman and MD in the private sector are held separately.
The Central Bureau of Investigation has started a preliminary enquiry looking into the Rs 950 crore (Rs 9.5 billion) alleged bad loan given by IDBI Bank to Kingfisher Airlines ignoring the company's negative credit ratings and net worth.
For the first time, PSU banks will have a non-executive chairman, giving operational responsibility to managing director and chief executive officer.