AT&T allowing iPhone users to access Skype.

AT&T, the biggest U.S. cellphone provider, said Tuesday that Apple iPhone users will be able to use Skype over its cellphone network, a move that will lower the cost of local and international voice calls.

The wireless network provider did not allow users of voice chat services like Skype from connecting over its wireless data network. The Skype application on Apple's iPhone could make calls only when connected to a Wi-Fi network.

"All of us at Skype applaud today's announcement by AT&T (in an FCC filing to be published shortly) that it'll open up its 3G network to internet calling applications such as Skype," wrote Skype president Josh Silverman.

"It's the right step for AT&T, Apple, millions of mobile Skype users and the internet itself."

Skype rolled out its internet calling application for the iPhone, as well as the iPod Touch, in many countries six months ago, and in Canada last month.

AT&T and other cellphone carriers have not allowed Skype to connect to their 3G networks as they showed concerns that customers would drop their voice plans, which are a big source of revenue. By allowing cellular Skype connections, AT&T is risking customers paring down their monthly bills to just data plans.

Silverman said that although AT&T's move was a good step, the FCC's rules are still needed.

"Nonetheless, the positive actions of one company are no substitute for a government policy that protects openness and benefits consumers," he wrote.