The Belgian Competition Authority ("BCA") published Guidelines, addressed to procurement officials, with a view to preventing and detecting "bid-rigging". The Guidelines find their inspiration in texts such as the OECD Guidelines for Fighting bid rigging. They provide an overview (i) of indications that bid-rigging practices occur, (ii) of market circumstances that facilitate bid-rigging, and (iii) of best practices to prevent bid-rigging.
First, after identifying the different forms of bid-rigging schemes (cover bidding, bid suppression, bid rotation and market allocation) and concomitant compensation schemes within a cartel (e.g. through sub-contracting to competitors), the Guidelines list several indicators that may hint at the existence of a bid-rigging cartel including: