WASHINGTON (REUTERS) - United States (US) antitrust regulators said on Tuesday they would pounce on Google Inc if they learned that the company, which dominates Internet search, violated the law after reaching an antitrust settlement in January.

The chairman of the Federal Trade Commission (FTC), Ms r Edith Ramirez, who became head of the FTC in early March, defended the agreement with Google at a congressional hearing.

The FTC concluded that Google had not manipulated its Web search results to hurt rivals, but extracted promises that the company would end the practice of "scraping" reviews and other data from rivals' websites - a practice that involved culling material from other websites and then putting them on Google Places - and allow advertisers to export data to independently evaluate advertising effectiveness.

The FTC did not, however, require a legally binding consent decree as is normally the case, an omission that angered Google's critics.

Queried about the decision to not seek a consent decree, Ms Ramirez told the Senate Judiciary Committee's antitrust subcommittee she fully expected Google to live up to its agreement, even in the absence of a court filing.

"The agency will take appropriate action if Google does not," she said.

"I share your concern... that the voluntary commitments would create confusion over settlement practices at the commission. What I can tell you is that that matter should not be considered a precedent," she added.

Mr Bill Baer, the Justice Department's assistant attorney general for antitrust, whose agency shares with the FTC the work of enforcing antitrust law, was asked how the Justice Department would react if Google were found to break antitrust law.

The FTC and Justice Department "would have a prompt conversation about who is best equipped to" investigate, said Mr Baer, who took over as head of the division in early January.

The FTC did seek a consent decree for a Google agreement to no longer request sales bans when suing companies that infringe on patents that are essential to ensuring interoperability, also known as standard essential patents.

The FTC investigation came after Microsoft Corp, Yelp and other Google competitors pressed the agency and European antitrust regulators to bring a broad antitrust case against Google similar to the sweeping Justice Department litigation against Microsoft in the 1990s.

Google gave European Union (EU) competition regulators a package of concessions this month, and the Brussels-based agency said it would begin the process of market testing the offer.

Their probe began in November 2010.