Google chairman Eric Schmidt has survived a Senate antitrust hearing, though questions definitely remain about the search giant's practices.

After starting the hearing by explaining how Google is different to frequent antitrust targets Microsoft, Schmidt was forced to defend his company from panel members, who queried whether it was possible for Google to be both an unbiased search engine and a provider of web-based products and services.

Republican Senator Mike Lee showed a chart comparing search rankings for Google Product Search alongside three comparison shopping sites, Nextag, PriceGrabber and Shopper.

Google ranked consistently third, while the others ranked anywhere from first to 50th, Lee said.

Schmidt responded that the comparison was an ‘apples to oranges' demonstration, as the Google service was not a product comparison site like the others.

When Lee continued to argue that Google ‘cooked' the results to make sure it was always number three, Schmidt replied testily, "Senator, may I simply say that I can assure you we've not cooked anything.

Later it was the turn of Google's rivals to speak before the panel, and they were vehement that Google is not fighting a fair fight.

Nextag chief executive, Jeff Katz, stated outright, "Google doesn't play fair. Google rigs its results.

"What Google engineering giveth, Google marketing taketh away.

Jeremy Stoppelman, chief executive and co-founder of search site Yelp, was equally critical.

"They prefer to send consumers to the most profitable sites on the web: their own,” Stoppelman said.