Consolidation Prevention and Competition Promotion Act of 2017 This bill amends the Clayton Act to revise merger requirements. Specifically, the bill: prohibits a merger that materially (currently, substantially) lessens competition in more than a de minimis amount or tends to create a monopsony (a market situation in which there is only one buyer), shifts the burden of proof to the merging companies that their consolidation will not harm competition, requires companies that enter into a settlement agreement with the Federal Trade Commission (FTC) or Department of Justice regarding a merger to report information that allows the agencies to assess the competitive impact of the merger, and establishes the Office of the Competition Advocate within the FTC.