After various reports that the Federal Trade Commission was going to launch a big investigation into Google’s business practices, this was finally confirmed in late June, though little information was revealed as to what specifically the FTC was looking at.

The Wall Street Journal is now reporting, citing “people familiar with the probe,” that Google’s Android and web search businesses will be key areas of focus. This is hardly surprising, but it does shed a little more light on the investigation. The WSJ’s Thomas Catan and Amir Efrati report:

Federal Trade Commission lawyers, in conjunction with several state attorneys general, have been asking whether Google prevents smartphone manufacturers that use its Android operating system from using competitors’ services, these people said.

They also have inquired whether Google grants preferential placement on its website to its own products, such as Google’s “Places” business listings, its “Shopping results” and Google Finance services above most other results.

When Google first officially acknowledged the probe in June, it outlined five principles of its business strategy that it says will stand up to scrutiny, including: doing what’s best for the user, providing the most relevant answers as quickly as possible, labeling ads clearly, being transparent, and “loyalty, not lock-in”. That last one refers to control over data (see Google’s Data Liberation Front efforts).

“It’s still unclear exactly what the FTC’s concerns are, but we’re clear about where we stand,” Google’s Amit Singhal said at the time. He also sprinkled in a bit at the end about Google “ensuring that businesses can grow and create jobs.”

Google is also scheduled to give testimony with the U.S. Senate Judiciary Subcommittee on Antitrust on September 21. Former CEO and current executive chairman Eric Schmidt will testify.