Collusion

secretive cooperation or deceitful agreement in order to deceive others, which may involve unions, wage fixing, kickbacks, or misrepresenting the independence of the relationship between the colluding parties

A collusion is a secret agreement between two or more people or groups, usually to create unlawful advantages over other groups. Collusions often organize secret agreements to gain an advantage by modifying the market unfairly. In businesses, this is often done by intentionally by secretly changing the supply and demand of goods and services.

Sometimes major companies will use collusions to make significant advantages over other companies by the use of cartels (the creation of unfair trade deals).