WASHINGTON – A published report says federal regulators are preparing to issue subpoenas to Google and other companies as authorities gather information for a broad antitrust probe into the Internet search leader’s business practices.

The Wall Street Journal reported Thursday that the Federal Trade Commission will issue subpoenas “within days,” which would signal that it has opened a formal investigation.

The FTC is looking into whether Google abuses its dominance of Internet search to extend its influence into other lucrative online markets, such as mapping, comparison shopping and travel.

Rivals complain that Google Inc., which handles two out of every three Internet searches in the United States, manipulates its results to steer users to its own sites and services and bury links to competitors.

The European Commission and the Texas attorney general have already opened investigations into whether Google uses its enormous clout as a major gateway to the Internet to stifle competition online.

The EU launched its investigation after competitors — U.K.-based price comparison site Foundem, French legal search engine ejustice.fr and Microsoft-owned shopping site Ciao — complained that their services were being buried in Google search results.

The Senate Judiciary Committee’s antitrust subcommittee is also examining whether Google gives its own services favorable treatment in search results and is seeking to have either Google Chairman Eric Schmidt or Chief Executive Larry Page testify before the panel.