The reports from The New York Times, Bloomberg News and Reuters cited unnamed people briefed on the FTC's investigation.
FTC spokesman Peter Kaplan declined to comment.
The agency has been investigating Google's business practices. The probe was triggered by complaints that Google Inc. has been highlighting its peripheral services in its influential search results and relegating offerings from its rivals to the back pages.
The FTC also has been looking into whether Google has rigged its results in a way that has prodded websites to pay more to promote their services through Google's advertising network.
In a statement Friday, Google said, "We are happy to answer any questions that regulators have about our business."
Google is based in Mountain View, Calif.