By Brendan Sasso - 12/19/11 11:34 PM EST
Sens. Herb Kohl (D-Wis.) and Mike LeeMike LeeThe impact of silence: The incarceration of children who have committed no crime Fidelity denies lobbying for student loan tax break Cruz, Lee question legality of Iran payment MORE (R-Utah), the top lawmakers on the Judiciary Committee's antitrust subpanel, are urging Federal Trade Commission (FTC) Chairman Jon Leibowitz to take a hard look at whether Google is engaging in anticompetitive business practices.
The lawmakers said their Sept. 21 hearing on Google left them with concerns that "warrant a thorough investigation by the FTC."
The FTC has acknowledged it is probing the Web giant.
They noted that at the hearing, when Google Executive Chairman Eric Schmidt was asked whether his company has a monopoly on online search, he said, "I would agree, senator, that we're in that area."
"Given the scope of Google's market share in general Internet search, a key question is whether Google is using its market power to steer users to its own web products or secondary services and discriminating against other websites with which it competes," the lawmakers wrote in a letter sent Monday.
A Google spokesman noted that the senators did not take a position on whether the company has run afoul of antitrust law.
“These letters are customary, and we appreciate that the committee reserved judgment as we continue to cooperate with the FTC," the spokesman said in an email. "We are committed to competing fairly on the Internet’s level playing field.”
Google acknowledges that it sometimes supplies its own answer to user questions at the top of its search results. For example, if a user asks about a company's stock price, Google will supply an answer using Google Finance.
The lawmakers said that because the vast majority of users click on one of the top three links, supplying a top answer could be a "significant when analyzing Google's potentially anti-competitive practices."
Kohl and Lee noted that at the September hearing, Nextag CEO Jeffrey Katz accused Google of penalizing his company's search results..
"If these allegations are true, they raise serious questions as to whether Google is penalizing these competing websites simply in order to maintain its dominant share in Internet search," they wrote.
The senators urged Chairman Leibowitz to scrutinize Google's dominance of searches on mobile phones. About 97 percent of mobile searches use Google.
The lawmakers are worried that Google might require phone companies to use its search engine as the default on devices using its Android Operating System. Google denies that it makes this demand.