The top U.S. communications regulator praised recent moves by big wireless companies to open their networks and said he would work to overcome a looming shortage of airwaves used by the industry.

U.S. Federal Communications Commission Chairman Julius Genachowski said on Wednesday that consumers would benefit from the latest move by AT&T Inc to open its network to Internet voice services and a partnership between Verizon Wireless and Google Inc.

In a speech to the CTIA wireless industry trade association convention in San Diego, Genachowski sympathized with wireless industry fears that the explosive growth in smartphones would lead to a shortage of airwaves.

I believe that that the biggest threat to the future of mobile in America is the looming spectrum crisis, he said.

Last year the FCC auctioned a swathe of spectrum that generated more than $19 billion in revenue for the U.S. government. A block allocated for shared use with public safety officials did not sell. Companies are clamoring for more with an expected jump in the use of voice, email and videos.

We must promote more efficient use of spectrum, he said.

T-Mobile, a unit of Deutsche Telekom AG, is among the carriers seeking more spectrum to better compete with AT&T and Verizon Wireless, a venture of Verizon Communications Inc and Vodafone Group Plc.

The industry's efforts to erect cellphone towers in communities have been stymied by local municipalities concerned that they are eyesores.

He said the FCC will soon move forward with a deadline proposal designed to speed the process, while taking into account local authorities' concerns.

Genachowski's remarks come one day after industry announcements that would allow cellphone users to make cheap calls via the Internet.

The issue of cheaper Internet voice calls is tied into his efforts to propose a Net neutrality rule aimed at ensuring that network operators like AT&T, Verizon and cable provider Comcast Corp treat the flow of Internet content and applications without discrimination.

There shouldn't be any confusion, he said. I believe firmly in the need for the FCC to preserve Internet openness, whether a person accesses the Internet from a desktop computer or a wireless laptop or netbook.

The president of AT&T Mobility & Consumer Markets, Ralph de la Vega, said at the convention, We believe there is no abuse taking place and no need to burden the Internet with more regulations.

As the FCC prepares for an October 22 meeting to propose the rule, the agency is also examining the spat between Google and Apple over why the Google Voice app is not available on the iPhone.

Google said Apple rejected it. But Apple said it was still studying it because the application alters the iPhone's telephone functionality and user interface.

We take Apple at its word that it is looking at it and hasn't made a decision yet, Genachowski said in a CNBC interview. We encourage them to continue to look at it.

Google, the world's largest Internet search company, said it was teaming up with Verizon Wireless to co-develop multiple phones based on its Android operating system. Google's Voice application would be on the new phones.

Separately, AT&T, which has exclusive rights to Apple Inc's iPhone in the United States, said it will open its third-generation wireless network to third-party Internet voice applications, clearing the way for services such as Skype.

(Reporting by Gina Keating; Writing by John Poirier; Editing by Tim Dobbyn, Leslie Gevirtz)