Earlier this week Newbury, UK-based Vodafone trumpeted an agreement with Microsoft Corp, whereby Microsoft’s Windows Mobile 5.0 is one of the three platforms Vodafone will support for its next five years of development. The other two are Linux and Symbian/Series 60, which is Symbian with the S60 user interface that was developed by, belongs to and is licensed by Nokia Corp.

London-based Sony Ericsson, on the other hand, develops phones on the Symbian OS, but uses the UIQ interface and yesterday announced the acquisition of UIQ Technology AB from its former owner, Symbian Ltd. Of course, Sony Ericsson is a shareholder in Symbian, the consortium set up in 1998 to develop and drive the adoption of the smart phone OS.

However, Nokia holds the largest stake, and as such was also the biggest shareholder in UIQ, and as the primary licensee of that UI, Sony Ericsson has moved to gain control of that technology (see accompanying story in this edition).

Neither the handset manufacturer nor the carrier, which currently has Sony Ericsson phones in its portfolio, were particularly demonstrative about the latest turn of events in terms of UIQ’s exit from the family of platforms of choice for Vodafone’s smart phone offerings.

A spokesperson for Sony Ericsson said that the information contained in the Vodafone announcement of its three-OS strategy wasn’t news to us, but that it formed part of the internal discussions between business partners, and so could not be the subject of any further comment. We don’t want to be drawn into commenting on our customers’ business plans, the spokesperson went on.

A counterpart at Vodafone, meanwhile, remarked that basically, before announcing this we did full evaluation of the industry. UIQ was considered but ruled out, presumably on rationalization issues. As to the acquisition of UIQ by Sony Ericsson, he said it was not a surprise, adding that we however remain committed to our three core platforms, and comment-wise that is as far as we can go at the moment. We will continue to look at the market.

The options open to Sony Ericsson, if it wants to stay on Vodafone’s books with its smart phones, are to add an S60 phone to its line-up, though that would stick in the gullet in that it would have to license the technology from its larger rival, or to start to develop phones on WM5 or Linux, neither of which it appears willing to do at the moment.

Of course, it could still attack the phone retail channels rather than go through the carrier, and indeed its phones could still be sold with Vodafone SIM cards, but that would exempt them from the subsidies handsets enjoy from carriers, as well as representing a more complicated sale from the point of view of support.