The curved LG G Flex smartphone is now available to pre-order in the UK, with an eye-watering price tag of £690 without a contract.

Featuring a curved 6in display, the G Flex was announced back in October, just weeks after fellow South Korean smartphone maker Samsung revealed the Galaxy Round, also with a concave display.

The difference between the two is that the G Flex's screen curves from top to bottom, whereas the Galaxy Round bends from left to right (with the phones held in portrait). LG claims this difference makes the G Flex more comfortable to make phone calls on, while providing a more immersive video experience.

With 32GB of storage, the G Flex is £60 more expensive than the equivalent iPhone 5s. On contract, the G Flex starts from £29.99 per month, but this requires an up-front payment of £449. For £42 per month the handset price drops to a more reasonable £149 up-front.

LG has previosuly said the G Flex will go on sale in the UK in February, but online retailer Expansys is claiming a release date of 20 January.

'Self-healing' technology

Aside from the curved screen, the G Flex also boasts a rear cover with "self-healing" technology, which is a protective skin LG claims can remove scratches from the phone within minutes of them appearing.

Also on the rear of the device is a 13-megapixel camera, along with the home button and volume controls - a design mirrored by the company's flagship G2 smartphone.

As for specifications, the G Flex's screen has an HD resolution of 1,280 x 720 - giving a pixel density of 245 per inch, which is much less than the Samsung Galaxy S4's 440ppi.

Inside, the phone is powered by a 2.3GHz quad-core processor with 2GB of RAM and running Android 4.2 (Jelly Bean), which is two generations behind Google's newest version of its mobile operating system - Android 4.4.2 (KitKat).

Thanks to the huge screen, LG has managed to fit the phone with a 3,500mAh battery, much larger than the 2,600mAh capacity of the Samsung Galaxy S4.

Both the LG G Flex and Samsung Galaxy Round are likely only being launched to test customer reaction to curved screens, although claimed improvements in strength and durability will go same way to reassuring consumers wary of the ease with which the glass displays of some phones can be damaged.