The rejection by Apple of a Google Voice application that would allow iPhone owners more options in how they place calls is “very troubling,” according to our colleagues at Consumers Union, the parent company of Consumer Reports.

The app is available now for Blackberrys, and for Google phones such as T-Mobile’s G1, now in our smart phone Ratings (available to subscribers), and the upcoming MyTouch 3G, which will soon be.

Google Voice is designed to route work, home and wireless phones to a single number provided by the Internet search giant. Other features include free local and cheap international calls and even transcripts of voicemail phone messages in your email inbox.

In a blog post on its HearUsNow.org website, CU says that Apple rejected the app because “Google Voice effectively gives away for free many of the services that AT&T makes a lot of money selling." And it links that decision to the exclusivity arrangements that are prevalent for many cell phones, including the iPhone, and that CU opposes.

“It’s safe to say that Apple would not have rejected Google Voice for the iPhone were it not for its exclusive service deal with AT&T, “ CU says.