Google will today announce its long-awaited mobile strategy, according to sources.

Company negotiators were hammering out agreements with wireless carriers, handset makers, software developers and hardware providers, over the weekend. Google is expected to reveal an ambitious platform for creating mobile applications.

Although Google has declined to comment for months, sources said the company will show its hand today at 4pm GMT, and that details of the plan were being finalised this weekend.

Google will announce an open source development platform for mobile applications that will contain an operating system, a set of APIs, a middleware layer, a customisable user interface and even a mobile browser, sources said. Instant messaging protocols will also be supported.

The platform is intended to simplify the process of creating and deploying mobile applications, so that an application can be built once and be compatible with multiple phones.

On the partner side, well over 30 industry heavyweights are already on board, including Intel, Qualcomm, Broadcom, Nvidia, Sprint Nextel, T-Mobile, China Mobile, Telefonica, NTT DoCoMo, LG Electronics and HTC, the sources said.

With talks continuing over the last few days, it's possible that the list could exceed 40 partners. Among those not listed so far are Nokia, Verizon and Apple.

The development platform will be freely available to anyone who wants to use it, and, aside from a common core, will provide a lot of flexibility for modifications and extensions.

The ultimate goal is to lower the costs and simplify the creation of mobile applications and spur innovation that, as Google sees it, has been hampered by technical fragmentation. As such, the Google offering will rival platforms from Microsoft and Symbian.

For Google, the benefit will come indirectly from improvements to phone interfaces, which the company reasons will make it easier for people to access online services, like search engines, and applications, from their mobile phones.

As usage of Google online services increases on mobile devices, so will the advertising revenue the company generates.

As the Google deal takes its final shape, it appears more and more likely that it might pit Google against its traditional ally Apple, and align it with carriers that have been hurt by the success of the iPhone.

Although the platform will be available to anyone, including Apple, it could indirectly accelerate the pace at which competing handsets catch up with the iPhone's user experience innovations.

A few weeks ago, Apple announced it will release a software development kit so that third-party developers can build applications for the iPhone. It expects to make it available in February.

If Apple is absent from the partner list in today's announcement, it could signal that Steve Jobs's company views the Google platform as a negative development, an interesting situation, considering Google's CEO Eric Schmidt sits on Apple's board.

As has been reported previously, the components of the Google platform will not be delivered until at least mid-2008. At some point, the effort might even yield a Google-branded phone, sources said.