Senator Herb Kohl, a Wisconsin Democrat, listed search and broadband competition among the top issues that the antitrust subcommittee of the Senate Judiciary will explore between now and the end of 2012.

"Millions of consumers rely every day on competitive markets to keep prices low, and quality of goods and services high," Kohl, the subcommittee's chairman, said in a statement this week. "On the antitrust subcommittee we have found, in industry after industry, that the best way to ensure full and fair competition is through the vigorous enforcement of antitrust law. We will continue to work on the subcommittee to ensure that antitrust law is strongly applied."

Kohl's focus on search-engine competition comes after complaints from some websites about the fairness of Google rankings. Kohl has also questioned the search-engine giant's recent acquisitions, including a planned purchase of travel and airline vendor ITA Software. In December, Kohl to carefully review the ITA acquisition.

"Participants in the on-line travel industry are concerned that Google could refuse to make the key components of ITA software available on reasonable terms to other online travel industry participants by raising the price for a renewed license or refusing to license improvements to the software," Kohl wrote to the DOJ. "As a result, consumers would suffer harm if there is less price transparency from competing air travel search providers, which would harm consumers' ability to obtain the lowest airfares."

The antitrust subcommittee will focus on Google acquisitions and on general competition in the search industry, Kohl said in a press release.