San Francisco - Hoping to challenge the popular iPhone and carve out a dominant position in the transition of the internet to mobile networks, Google launched its first mobile phone Tuesday in the US in conjunction with the German-owned carrier T-Mobile.

The new device, called the T-Mobile G1, functions on 3G networks and is specially designed to offer high-speed access to popular Google services such as search, Gmail, Google maps with directions and YouTube.

It also features a touch screen and a slide-out keyboard, a feature that could give it an advantage over the iPhone.

A mobile version of Amazon's MP3 store will be preloaded onto the G1, which will allow users to search, download, buy and play music directly from the popular music store.

The G1 will support the Android Market, a mobile application in which third party developers can offer additional programmes for the device, which is manufactured by Taiwanese electronics maker HTC.

It also features the Android operating system that had been developed by teams of Google engineers over the last three years. Android is an open source system than can be used and changed by any device manufacturer.

Google, which currently dominates advertising on the internet, hopes that with Android it will become the standard operating system for increasingly sophisticated mobile phones, which experts believe will provide the main access to the internet for billions of people without computers.

The G1 is priced at 179 dollars, 20 dollars less than the iPhone, and will be available from October 22.

Its data plans are also far less than those available for the iPhone in the US, with an unlimited text and internet plan costing just 35 dollars, in addition to regular voice plans.

The G1 will be available in the UK in November and across Europe in the first quarter of 2009. (dpa)