According to Ad Age Digital, the U.S. antitrust enforcers are investigating whether Google illegally increased advertising rates 50-fold for rival Microsoft. The Federal Trade Commission is probing the increase, along with other allegations against Google related to advertising, as a result of complaints from Microsoft.
A U.S. Senate panel is holding a hearing entitled "The Power of Google: Serving Consumers or Threatening Competition?" at which Google Chairman Eric Schmidt may be asked about the FTC's antitrust probe.
Google controlled 59% of the U.S. online search advertising market in the second quarter of this year, compared with second-place Microsoft at 9% and Yahoo at 7%, according to a report by IDC this week.
Several companies that advertise on Google's search results declined to comment on its advertising practices. Those declining to comment were AT&T, Monster Worldwide, Vonage and Dell.