The first mobile phones fitted with Google's Android software platform made their debut at an industry trade show on Monday, a key advance in the struggle to bring the power of desktop computing to handsets.

Google launched Android last year, hoping to establish its software as the dominant operating system for mobile phones and to improve the quality of web-browsing for handset users.

What is happening with Android today is that we are seeing a number of technology companies demonstrating how Android will operate on their technology, Google spokesman Barry Schnitt told AFP on the sidelines of the Mobile World Congress.

Although the technology on display Monday is in prototype form, experts and journalists were so eager to witness its demonstration that all places for private displays were booked out on Monday within the first hour of the show.

It's definitely very promising, an analyst for technology research firm Gartner, Carolina Milanesi, told AFP. This means that we should be on track to see commercial devices in the second half of 2008.

She stressed however that the road between a prototype and commercial handset is a long one.

Google announced a broad 34-member group called the Open Handset Alliance in November last year to develop Android, including China Mobile, HTC, Intel, Motorola, Qualcomm, T-Mobile, Telefonica, LG and eBay.

The demonstrations Monday were by a handful of chip makers -- ARM, Marvell, Texas Instruments, Qualcomm, NEC and ST Microelectronics -- which showed Android working in prototype form, the companies and sources confirmed.

We're demonstrating a prototype of Android, a spokesman for ARM told AFP.

US chip maker Texas Instruments is to demonstrate another prototype phone later Monday in public.

Android is open-source software, meaning its code is available to other developers for free allowing them to build applications and features that can function on the operating platform.

The idea for Google is that Android will lead to radically improved functionality, notably for web browsing, meaning more people will use their mobile phones for Internet surfing.

Currently, surfing the Internet on a mobile phone can still be a frustrating experience, with clunky software and slow download speeds.

There are few phones that provide a compelling web experience, explained Google's Schnitt.

As people use the web more, they'll use Google more, and we'll be able to sell more relevant advertising.

Milanesi said that the ultimate test of Android's success would be how easily applications could be used.

It should have everything that we see on the PC, not just shrunk down to work on a mobile phone but really being optimised for a mobile phone, she said.

Android faces competition from the world's biggest mobile phone maker, Nokia, and its Symbian system; US software giant Microsoft, the maker of Windows; and a separate consortium working on an open-source Linux solution.

The interest in a new software platform from Google stems from the company's desire to establish its brand in emerging markets.

If you look at emerging markets, people are more likely to have their first browsing experience on a phone not a PC (personal computer), said Milanesi.

Google surprised analysts when it unveiled Android last November. They had expected the Internet giant to announce the launch of its own gPhone to compete against Apple's popular iPhone.

Imagine not just a single Google phone, or G-phone, but thousands of G-phones made by a variety of manufacturers, said Google chief executive Eric Schmidt at the time.

This could be Android's weak spot, however.

Taiwan's HTC and ailing US manufacturer Motorola are the two main handset manufacturers in the Open Handset Alliance.

For it to become a worldwide platform and drive uptake, they need more manufacturers onboard, said Milanesi.