from www.ft.com – AT&T, the largest US telecommunications group, called on federal regulators to force Google, the internet search and advertising giant, to “play by the same rules as its competitors” and ensure that its Google Voice application does not block calls to some rural areas.

The call, which came in a strongly worded letter from AT&T to the Federal Communications Commission’s competition bureau was signed by Robert Quinn, AT&T’s senior vice president for federal regulations. It marks a significant escalation in the dispute over Google Voice and proposed new rules on “net-neutrality.”

The FCC is already investigating Apple’s decision to reject the Google Voice application for the iPhone which enables customers to send and receive calls from a single telephone number on multiple devices and access voice mail. AT&T is the exclusive provider for the iPhone in the US.

Last week, Julius Genachowski, FCC chairman, proposed new rules requiring operators to open their networks to any legitimate internet content or service without discrimination. If adopted, the move would be a victory for big internet companies at the expense of network operators.

AT&T and other traditional US carriers have argued that the existing net neutrality guidelines are sufficient and some have rejected the need to extend them to mobile services. Carriers argue that they want the flexibility of being able to protect their networks from bandwidth-hogging applications including video services.

In its letter on Friday, AT&T described Google as “one of the most troublesome trumpeters of so-called net-neutrality” regulation, but said it failed to abide by “level playing-field” principles “at least when it comes to its own services.”

AT&T noted that numerous press reports have suggested that Google “is systematically blocking telephone calls from consumers that use Google Voice to call telephone numbers in certain rural areas.”

By blocking these calls, AT&T claimed that Google is able to reduce its access expenses while, “other providers, including those with which Google Voice competes, are banned from call blocking” by a 2007 FCC ruling.

The dispute over Google Voice has at its core, an argument over whether Google Voice is a telecommunications service, and therefore subject to regulation or, as Google maintains, “an online software tool” and therefore outside the regulatory framework.

However AT&T contends that even if Google Voice is an application, it is still bound by the Commission’s Internet Policy Statement principles. ”To the extent ’net neutrality’ is animated by a concern about ostensible internet ’gatekeepers,’ that concern must necessarily apply to application, service, and content providers,” said Mr Quinn.