The Federal Communications Commission, the US telecoms regulator, is seeking clarification as to why Apple has barred Google’s voice application from its App Store, reports Reuters. The regulator has submitted open letters to Google, Apple and AT&T – the mobile operator that offers Apple’s iPhone on an exclusive basis in the US – as part of its recent investigation into open access and handset exclusivity in the country’s mobile market. The investigation into the matter follows concerns that Apple may have colluded with AT&T to block a service that threatened to cannibalise the operator’s voice revenue. In its letter to Apple, the FCC asked for the reason behind the rejection and the decision to remove the third-party application. It also asked whether Apple acted alone or in consultation with AT&T, and what role AT&T plays in the approval process for iPhone apps. The Google Voice application can be used to make low-priced international calls, and offers a single phone number that can route incoming calls to home, office and mobile phones. A separate third-party Google Voice application for the iPhone – GV Mobile – has also been removed from the App Store.

Meanwhile, another US government body – the Federal Trade Commission (FTC) – has said it will continue its investigation into the relationship between Google and Apple despite Google chief executive Eric Schmidt’s decision yesterday to resign from Apple’s board. According to Reuters, Richard Feinstein, director of the FTC’s bureau of competition, praised Schmidt’s move in light of the increasing competition between the two firms, but noted that “we will continue to investigate remaining interlocking directorates between the companies.” Anti-trust experts believe the FTC is keeping the case open because another person – former Genentech CEO Arthur Levinson – remains a director of both companies.