Google executive chairman Eric Schmidt rejected charges that the Internet giant has "cooked" search results to favor its own services during a grilling on Wednesday by a Senate antitrust panel.
Schmidt, appearing before the Senate Judiciary Subcommittee on Antitrust, Competition Policy and Consumer Rights, also sought to distance Google from Microsoft, which was the target of US antitrust action in the late 1990s.
During an hour-and-a-half of testimony, Schmidt repeatedly stressed that Google's search algorithms are designed to return the best results for users and are not rigged to give preference to its own products or services.
Republican Senator Mike Lee of Utah was not convinced and pointed to a study of product search results in which he said Google Product Search displayed an "uncanny" ability to repeatedly show up third in the rankings.
"You've cooked it so that you're always third," Lee said.
"Senator, may I simply say that I can assure you we have not cooked anything," Schmidt replied.
Lee said Google may not qualify as a monopoly under antitrust laws but the company "is in a position to help determine who will succeed and who will fail on the Internet."
"In the words of the head of Google's search ranking team, Google is, 'The biggest king-maker on Earth,'" he said.
While Lee subjected Schmidt to the toughest questioning of the day, other senators expressed their affection for the company or said they were undecided about whether Google is abusing its power.
"I love Google," said Democratic Senator Al Franken of Minnesota. "Google has utterly transformed the way we locate and use information."
At the same time, Franken said he found Schmidt's answers "fuzzy" about whether Google favors its own products in search results over those of its rivals.
Jeremy Stoppelman, co-founder and chief executive of online restaurant review site Yelp, told the subcommittee that Google "is no longer in the business of sending people to the best sources of information on the Web.
"It now hopes to be a destination site itself for one vertical market after another, including news, shopping, travel and now local business reviews," he said.
"Websites in Google's search results now take a back seat to Google's own competing products," Stoppelman said.
Schmidt, who stepped down after 10 years as Google's chief executive in April for co-founder Larry Page, opened the hearing on whether Google is abusing its dominance in Internet search with a reference to Microsoft.
"Twenty years ago, a large technology firm was setting the world on fire," he said. "But that company lost sight of what mattered and Washington stepped in.
"Many of us in Silicon Valley have absorbed the lessons of that era," Schmidt said. We get it. By that, I mean we get the lessons of our corporate predecessors."
The Mountain View, California-based Google has drawn increasing scrutiny from US and European regulators as it has grown over the years from a scrappy Silicon Valley startup into an Internet powerhouse.
European Union competition watchdogs began an investigation into Google in November and the US Federal Trade Commission (FTC) opened its own probe into the company's lucrative search and advertising business in June.
As it has grown, Google has branched out into various businesses including online mapping, shopping, travel and providing operating systems for mobile phones and tablet computers.
Schmidt said the challenge for Google is to provide the most relevant answers to users of its search engine.
"This means that not every website can come on top," he said. "It's a ranking problem and there are definitely complaints from businesses who want to be first in rankings even when they're not the best match, as best we can tell, for user search."
Schmidt also said that using Google is a choice for consumers and they can always go elsewhere.
"If you don't like the answer that Google search provides, you can switch to another engine with literally one click," he said.
"The ultimate correction against any mistakes that Google makes is how consumers behave," Schmidt said. "And we live in a great fear every day that consumers will switch extraordinarily quickly to other services."
According to the tracking firm comScore, Google accounted for 64.8 percent of US search market share in August followed by Yahoo! with 16.3 percent and Microsoft with 14.7 percent.
Explore further: Microsoft encourages antitrust scrutiny of Google