Control of a corporation occurs when a single institutional unit owning more than a half of the shares, or equity, of a corporation is able to control its policy and operations by outvoting all other shareholders, if necessary.

Similarly, a small, organised group of shareholders whose combined ownership of shares exceeds 50 per cent of the total is able to control the corporation by acting in concert.

In practice, when ownership of shares is widely diffused among a large number of shareholders, control may be secured by owning 20 per cent or less of the total shares.