An agreement between actual or potential competitors that sets, increases, or stabilizes their prices or that has an equivalent effect. Examples of cartels include agreements to:

The agreements are usually secret and informal. Cartel agreements are per se illegal under Section 1 of the Sherman Act.

For more information, see Practice Notes, Criminal Antitrust Enforcement in the US and US Antitrust Laws: Overview: Per Se Illegality and Cartels Toolkit.