At its monthly meeting, the agencyreleased findings of a study of unreported mergers for these five companies.
UnderHart-Scott-Rodino Act, companies are required to report to regulators only transactions that exceed $92 million in value.
Khan added she hoped the report would also be useful to Congress as itconsider reforming antitrust law.
Instead, she said it’s important to look at a company’s acquisitions in aggregate.
“I think of serial acquisitions as a Pac-Man strategy,” Slaughter said. "
Each individual merger viewed independently may not seem to have significant impact.
But the collective impact of hundreds of smaller acquisitions, can lead to a monopolistic behavior."
Commissioner Christine Wilson, a Republican, called for a similar study of health care mergers.
Last year, the commission sued Facebook, alleging that the social media company has violated antitrust law.
Both those deals had been reviewed by the FTC.
The FTC rarely intervenes in such deals.
The companies are each working to develop and market a blood test that diagnoses multiple cancer types.
