Sony has begun rolling out the Android 4.0 Ice Cream Sandwich upgrade for its smartphone devices in certain territories.
The company confirmed via a blog post that the update would initially be released in Sweden, Denmark, Iceland, Finland and Norway.
When asked by V3 when the update would arrive in the UK, Sony representatives were less forthcoming.
"The availability and scheduling of this software upgrade and specific models upgradeable to Android 4.0 will vary by market and carrier requirements," they said.
"We will publish a list of the released software kits on our support forum and update it on an on-going basis."
Sony also declined to provide guidance on when the ICS update would arrive for its S and P tablets.
"From a tablet and Walkman perspective we have no detail on when this update will arrive," said a Sony spokesperson.
Sony has already confirmed that the update will only be available for download via a PC or companion - meaning it will not be available as a download over 3G or Wi-Fi.
The update was announced by Sony earlier in April alongside a warning that it may affect some older handset's performance.
The company highlighted concerns over ICS's increased RAM usage, explaining that Xperia devices with 512MB RAM could struggle with certain apps and tasks.
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