Vodafone has picked Microsoft's Windows Mobile as the third operating system it will offer in its line of mobile phones.

Windows Mobile joins the Symbian operating system and Linux, which Vodafone has already said will drive its phones for the next five years.

Vodafone announced earlier this year that it would whittle down the number of operating systems it supports from more than 15 to two or three. By supporting just a few software platforms, Vodafone can cut application development costs and also offer more services to end users.

The company didn't have many other open operating system platforms to choose from, beyond Symbian OS, Windows Mobile and Linux. The operating system formerly known as Palm OS, bought by Access Co, is now based on Linux. Vodafone also sells BlackBerry devices, which run software from the device's creator, Research In Motion.

"The advantages of having these centralised platforms is it's a lot easier to roll out applications and services so users get a bigger selection of services," said Mark Street, a Vodafone spokesman.

Most mobile phone makers use their own proprietary software to run handsets, particularly lower end devices. Those operating systems typically have been adjusted and modified over the years, making it increasingly difficult for operators or handset makers to add new services to them. The operating systems from Symbian and Microsoft were built to accommodate the addition of new applications, and their creators encourage third-party developers to build applications for the platforms.

Vodafone chose Symbian and Microsoft in part because they have large existing communities of developers creating applications on the platforms. The mobile Linux developer community is also growing.