AT&T on Tuesday opened its 3G network to VoIP calls on the iPhone, reversing its previous position, as federal regulators consider applying proposed net neutrality rules to mobile phones.

AT&T's decision applies only to Apple's smartphone. The wireless carrier does not allow the use of voice over Internet protocol, or VoIP, over its 3G network on other mobile phones. Before the reversal, VoIP applications from Skype and other companies could make calls on the iPhone only over a Wi-Fi connection.

AT&T said it notified Apple and the Federal Communications Commission of its decision Tuesday. "Today's decision was make after evaluating our customers' expectations and use of the device compared to dozens of others we offer," Ralph de la Vega, president and chief executive of AT&T mobility and consumer markets, said in a statement.

The FCC is considering a proposal to formalize network neutrality principles, which will direct which competing services Internet providers must allow. The commission is also looking at whether to apply those principles to wireless networks.

Wireless providers and their supporters in Congress will likely fight having network neutrality principles applied to them. In general, their services haven't been affected by established rules governing wired networks.

AT&T has been among the most outspoken against applying net neutrality to wireless networks. AT&T argues that the nation's wireless landscape is very competitive without additional government involvement.

"We would thus be very disappointed if (the FCC) has already drawn a conclusion to regulate wireless services despite the absence of any compelling evidence of problems or abuse that would warrant government intervention," AT&T said in a recent statement.

AT&T's latest decision has no affect on Apple's denial of the Google Voice application for the iPhone. The application makes it possible to use one number to manage and receive calls from multiple numbers. AT&T has said it played no role in Apple's decision not to offer Google Voice. Apple's stand is under review by the FCC.

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