when two or more businesses who are competing to do work or provide services for a company, an organization, etc. secretly work together to gain an advantage for themselves and deceive the company buying the work or services. This is an illegal practice. 串通投标，操纵投标，围标（两家或多家投标企业共谋欺骗招标企业以获利，属非法行为）
when two or more people agree not to bid against each other at an auction in order to keep the price of the item lower than it should be. This is an illegal practice. 操纵拍卖（两人或多人商定在拍卖中不互相竞价以达到降低拍卖价格的目的，属非法行为）