Yahoo CEO Jerry Yang has told Microsoft executives that the company's search advertising deal with Google would reduce the Internet search market from two poles to one, Microsoft general counsel Brad Smith told U.S. lawmakers Tuesday.

The deal, which would allow Yahoo to display Google search advertising on its search pages, will make for reduced competition, and Yahoo has recognized that, Smith told the U.S. Senate Judiciary Committee's antitrust subcommittee . He told senators that Yang's comments came during a June 8 meeting between Yahoo and Microsoft executives.

Yang described the Internet search market as "bipolar," with Google on one side and Yahoo and Microsoft on the other, said Smith, who attended the meeting in San Jose, California. Yang told Microsoft executives that if the company signed the advertising deal with Google, it would become "part of Google's pole," and Microsoft would not be strong enough to compete, Smith recalled.

"The principle question is this: Can a single company establish effective control of 90 percent of the market for search advertising by entering into an agreement with its single largest competitor?" Smith told senators.

Michael Callahan, general counsel at Yahoo, said he didn't recall hearing Yang make the comments Smith attributed to him, but he disputed Smith's description of the tone of the June 8 meeting. Microsoft in recent months has made multiple offers to buy Yahoo or its search functionality, and the meeting was part of those talks, but Yahoo has so far rejected the Microsoft offers.

While the deal with Google, announced in June, would allow Yahoo to display Google search ads, the company plans to continue to offer its own search advertising system and compete with Google in basic search functionality and other areas, Callahan said.

"We are confident that the more one learns about this agreement, the more clear it becomes that it is good for competition -- good for consumers, good for advertisers, and yes, good for Yahoo," Callahan said. "The intent of Yahoo moving forward is to help make our company an even stronger competitor to Google, to Microsoft and to others in the dynamic and rapidly growing online advertising world."

Microsoft, the main opponent to the Yahoo/Google deal, owns about 90 percent of the operating system market and 80 percent of the Web browser market, said David Drummond, Google's chief legal officer. Microsoft has been trying to "destabilize" or buy Yahoo, he said, but the Google deal would leave Yahoo as a viable competitor online.