The U.S. government has launched an investigation into whether Internet search engine Google is using its dominance to promote its products while blocking competitors.

Google controls more than 65 percent of web searches worldwide and earns most of its money - billions of dollars - in search-related advertising.

The U.S. Federal Trade Commission (FTC) says it wants to know whether Google is using its dominance in searches not only to earn advertising revenue but also to channel users to its growing network of services.

The FTC investigation mirrors a similar probe the European Union opened last year.  The U.S. state of Texas also is looking at Google's business practices.

Google executives say they do not believe they are doing anything wrong or violating any antitrust laws.

In the 1990s the FTC looked into the business practices of Microsoft and whether it was using its Windows operating system to kill competing software makers.

That case was settled in 2002.  It was only last month that Microsoft emerged from government oversight.