Google has ended months of speculation about its plans for mobile phones by revealing details of Android, an open source software platform for mobile devices.

Android has been developed by Google in conjunction with the Open Handset Alliance, a new consortium of 34 global players from the mobile and technology industries. Qualcomm, Motorola and T-Mobile are among the group's founders, along with online auctioneer eBay and speech specialist Nuance.

The free software will act as an operating system for mobile phones but will also provide middleware functionality. Software development kits will be available from 12 November, while Google expects the first Android-enabled handsets to appear from the middle of next year.

The announcement thwarts previous predictions that Google was planning to launch a "G-phone" device to compete with Apple's iPhone, which is due to be released in the UK at the end of this week.

The open platform approach will instead offer wider opportunities for innovation and the growth of mobile applications, according to Google.

"This partnership will help unleash the potential of mobile technology for billions of users around the world," said chief executive Eric Schmidt.

"A fresh approach to fostering innovation in the mobile industry will help shape a new computing environment that will change the way people access and share information in the future," he said.

"Today's announcement is more ambitious than any single 'Google Phone' that the press has been speculating about over the past few weeks. Our vision is that the powerful platform we're unveiling will power thousands of different phone models."