Singhal also noted that on labeling advertisements correctly, being transparent about how their rankings work and providing the most relevant search results. "These are the principles that guide us, and we know they'll stand up to scrutiny," he said.

On Thursday, the that the FTC was gearing up to serve Google with civil subpoenas in what looked to be a formal, wide-ranging antitrust investigation into whether the company has abused its Web dominance.

Past federal investigations into Google focused on mergers and acquisitions. The new probe is a much broader look into the company's business practices and how much it might use its dominant position to muscle other players out of various markets.

The FTC action isn't the only antitrust investigation that Google has to deal with.

Late last fall, the European Commission launched an investigation into allegations that its heavily dominant position in online search to promote the company's other services.