Particular form of coordination between firms which can adversely affect the outcome of any sale or purchasing process in which bids are submitted. For example, firms may agree their bids in advance, deciding which firm will be the lowest bidder. Alternatively, they may agree not to bid or to rotate their bids by number or value of contracts.
Source: Glossary of terms used in EU competition policy, Antitrust and control of concentrations, European Commission, 2002