Internet calling companies such as eBay unit Skype have called on European policymakers to adopt policies that let consumers access their services through smart phones on any public network.

The Voice on the Net (VON) coalition Europe, which also includes Google Inc, Microsoft Corp and Intel Corp, argues carriers are blocking their applications on their cellular or 3G networks, which limits consumer choice.

The appeal was sparked by news that German mobile operator T-Mobile, the wireless unit of Deutsche Telekom, did not allow customers to use the Skype application on the iPhone.

T-Mobile is the exclusive carrier of Apple's iPhone in Germany.

Blocking of voice applications on mobile devices, such as the announcement of T-Mobile to block Skype on iPhones in Germany, is highly detrimental for consumer welfare in Europe, VON said in a statement.

Internet phone providers want to expand beyond desktop computers but carriers such as T-Mobile, AT&T or UK's O2 worry this could lead to a fall in their voice revenue.

While carriers can block Skype -- the Internet telephone unit of eBay Inc -- on their networks, they cannot distinguish whether customers are using Skype through a Wi-Fi link, a person familiar with the matter said.

Essentially, you can use Skype via Wi-Fi on a T-Mobile iPhone, the person said. I have tried, it works.

T-Mobile blocks Skype usage on its network, arguing the high level of traffic would hinder network performance.

Since Tuesday, Skype's iPhone application can be downloaded through the Apple application store on iPhones and allows free calls between Skype users.

As with Skype on the desktop, fees will be charged for calls to traditional phones.

In May it will launch Skype for Research In Motion's BlackBerry devices, which popularized mobile email.

It has already announced Skype for Nokia phones and for phones based on Android, Google mobile system, and Windows Mobile, from Microsoft.

(Reporting by Nicola Leske; Editing by Andrew Macdonald)

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