The US senator who chairs the subcommittee on anti-trust issues has announced plans to examine Google's "dominance" of the Internet search market.

Herb Kohl, a Democrat from Wisconsin who chairs the Senate Judiciary Committee's Subcommittee on Antitrust, Competition Policy, and Consumer Rights, put online search on the agenda for the new session of Congress.

Kohl said the subcommittee planned to address competition in online markets and Internet search issues.

"Access to the wealth of information and e-commerce on the Internet is essential for consumers and business alike," the senator said in a statement.

"The subcommittee will strive to ensure that this sector remains competitive, that Internet search is fair to its users and customers, advertisers have sufficient choices, and that consumers' privacy is guarded.

"In recent years, the dominance over Internet search of the world's largest search engine, Google, has increased and Google has increasingly sought to acquire e-commerce sites in myriad businesses," Kohl said.

"In this regard, we will closely examine allegations raised by e-commerce websites that compete with Google that they are being treated unfairly in search ranking, and in their ability to purchase search advertising.

"We also will continue to closely examine the impact of further acquisitions in this sector," Kohl said.

The Justice Department is currently reviewing Google's proposed $700 million acquisition of flight information company ITA Software, a deal which is facing opposition from several leading online travel sites.

According to figures released on Friday by tracking firm comScore, Google remains the overwhelming leader of the US search market although its US market share slipped to 65.4 percent in February from 65.6 percent in January.

Yahoo!'s share of the US search market was unchanged at 16.1 percent while Microsoft's share increased to 13.6 percent in February from 13.1 percent in January.