O2 is offering the Android smartphone on contract, while online outlets such as The Clove and Play are selling the handset.
The Xperia Ray is 9.4mm thick with a 3.3 inch touch-screen and Mobile Bravia technology at its core. It also features a 1GHz processor and an eight mega-pixel camera. Android 2.3 is pre-installed and an 8GB microSD card comes bundled in.
The handset is priced between £299 and £315 in the UK, or is available for no additional payment from O2 on contracts from £18.50. It comes in black, while, pink or gold.
Vodafone and Orange have also announced that they will be offering the phone at a later date. Details of the call plans they will offer are yet to be revealed.
Sony released the PlayStation-certified Xperia Play smartphone earlier this year.
> PopCap games bundled with Sony Xperia Smartphones