Eric Schmidt, Google Inc.'s CEO, stood up to U.S senators Wednesday to defend his company against allegations that it skews search results in favor of its own online services.

Schmidt opened with a statement about the Microsoft antitrust case. Microsoft had to defend itself from government efforts to break the company up.

"Many of us in Silicon Valley have absorbed the lessons of that era," Schmidt said. "I ask you to remember that not all companies are cut from the same cloth, and that one company's past need not be another's future."

Senator Mike Lee (R-Utah) was one of Google's sharpest critics at the hearing and said that the search engine had "cooked it" to let Google's products and services appear before other companies in search results.

"Senator, may I simply say that I can assure you we've not cooked anything," Schmidt replied.

He also reiterated that Google's goal is to steer users to the most relevant information. He also pointed out that users can opt to use other search engines and that the antitrust probe targeting Google was instigated by Web sites that didn't like their rankings.

"There are definitely complaints from businesses who want to be first in rankings even when they're not the best match," he said.

Sen. Herb Kohl, D-Wis., chairman of the antitrust subcommittee, said Google's acquisition binge had transformed the search engine into a "major Internet conglomerate."

"These acquisitions raise a very fundamental question: Is it possible for Google to be both an unbiased search engine and at the same time own a vast portfolio of Web-based products and services?" he asked. "Does Google's transformation create an inherent conflict of interest which threatens to stifle competition?"

That is not the case, Schmidt replied. "I'm not sure Google is a rational business trying to maximize its own profits," he said.

For the most part Schmidt was able to remain unruffled from the senators' questions. But at some points he did make some lapses. At one point he seemed to admit that Google's market share in Internet search was "in the area" of a monopoly. Google's outside counsel, Susan Creighton, contradicted him later saying that Google didn't have a monopoly.

At another point, Schmidt was unable to answer definitively whether Google's own services were subject to the same standards as other companies in ranking search results.

"That seemed like a pretty fuzzy answer to me, coming from the chairman," said Sen. Al Franken, D-Minn. "If you don't know, who does?"

At the heart of the hearing is whether Google has hurt consumers with its aggressive acquisitions of other businesses like Motorola Mobility. The issue will also be studied in another antitrust investigation by the Federal Trade Commission. The Justice Department and European Union are also examining Google.

So far Google's rivals have failed to give proof that Google has harmed the fair competition.

"At this stage, all we know is that some rival firms have suffered as a result of Google's practices," said Keith Hylton, an antitrust expert at Boston University's School of Law. "But that doesn't tell us whether consumers have been harmed in any way."