Google Chief Executive Eric Schmidt told reporters at a news conference at the company's Silicon Valley headquarters that it anticipated objections to Google's growing ad market power and its impact on competition.

"We are quite certain that Microsoft is busy helping everyone get upset about these things," Schmidt said in response to a reporter's question about antitrust issues raised by rivals and industry trade groups to government regulators.

Schmidt said U.S. government regulators are doing their "proper job" in investigating his company's contract with Yahoo. He added that Google has answered questions raised by regulators but did not know how they would respond.

The executive underscored that Google believes it does not need to receive specific government approval to go ahead with its contract to supply advertising to run alongside a portion of Yahoo's Web search results. Schmidt said Google is committed to going ahead with the Yahoo deal, as planned, in October.

In response to a reporter's question, Schmidt declined to say whether Google and Yahoo would agree to set a limit on how many ads it delivers to Yahoo.