The U.S. Federal Trade Commission has subpoenaed Apple in order to get details about its mobile-search deal with Google, according to a report by Bloomberg.

Going by the report, the FTC has asked Apple particulars about the manner in which it is incorporating Google search on its iPad and iPhone. Google has long been the default search engine on Apple's iPad and the iPhone.

This move by the FTC is a clear suggestion that it is reinforcing its inspection of the business practices followed by Google. The focus is on concerns that Google unjustly promotes its own services in its search results.

The major concern is that Google, being the market leader among search engines, is further using its strength to cut off its competitors from its businesses. It is highly possible that the search results provided by Google could put business services it offers much higher than those of its competitors.

The regulators are also investigating Google+, which is the social networking service offered by Google. The major concern is to find out on whether Google is promoting Google+ in its search results and sidelining its competitors like Twitter and Facebook.