The decision would help the government raise close to Rs 60,000 crore from the sale of shares in around 36 listed PSUs where the public shareholding is less than 25 per cent.
Under current norms, government undertakings should have at least 10 per cent public shareholding whereas for non-PSU firms the minimum level is 25 per cent.
"Sebi believes that all the rules for markets should be neutral to the promoters. It should not be dependent upon who is the promoter," Securities and Exchange Board of India (Sebi) Chairman U K Sinha said after its board meeting here.
According to Sebi, the different minimum shareholding level for private and public sector companies is discriminatory and inconsistent with broader market design.
Sinha said: "Securities Contract Regulations (Rules) will be amended to provide that all public sector companies will also have 25 per cent (public shareholding).
"In order not to make it disruptive we have given them a three-year time frame within which they will have to meet our requirements.