Google plans to offer software to make the internet run as smoothly on mobile phones as it does on computers.
In its long-rumoured entry into the mobile phone market, the world's leading internet company said it would start next week by allowing independent designers to tinker with its software, known as "Android."
Google-based phones are due to appear in the latter half of next year marketed by Deutsche Telekom's T-Mobile.
Google, which has no immediate plans to make phones of its own, said it forged an alliance with 33 companies, including phone makers Motorola, Samsung and High Tech Computer Corp.
"We're hoping thousands of different mobile phones will be powered by Android," Google Chief Executive Eric Schmidt said.
Google said it is in no rush to see operators alter the way they charge for service but that new ways of making money such as advertising-subsidised offerings would eventually be possible.
Google said it aims to expand the range of web services it offers to the far-larger mobile phone market, where internet use is hampered by hundreds of conflicting handset designs and software standards.
The move pits Google against mobile operating systems backed by Nokia, Microsoft and Google partner Apple, maker of the iPhone. A number of Google partners said they would still work with rival systems.