Sony has announced the launch of the Sony Xperia Z Ultra, confirming the much-rumoured move into the phablet segment of the market.

Announced at a launch event in Shanghai, with a parallel event in London, the new Sony Xperia Z Ultra brings with it the features of the Sony Xperia Z, such as that slim design and the waterproofing, but adds to it with a larger 6.4-inch display.

The 1920 x 1080 Triluminos display, however, brings an additional benefit with it. Not only will it work with a stylus, but it will also let you scribble with any pen or pencil making it ideal for quick note-taking.

Sitting at the core of the Sony Xperia Z Ultra is the new quad-core Qualcomm Snapdragon 800 chipset, clocked at 2.2GHz. There's a 3000mAh battery, which Sony claims will give you 11 hours of 3G talk time. It's a 4G LTE handset, offering 16GB of internal memory, expandable via microSD up to 64GB.

The handset measures 179.4 x 92.2 x 6.5mm, sticking to that slim design that we liked from the Sony Xperia Z and Sony Xperia Tablet Z. It weighs 212g, so despite the size, isn't going to weigh you down too much. It will come in black, white and purple.

There's an 8-megapixel camera around the back, offering all the features you'd expect from an Xperia handset, like face detection, HDR, burst shooting and so on. This is joined by a 2-megapixel front-facing camera.

The Sony Xperia Z Ultra sits within an aluminium frame with a thin design which Tony Walder, senior design manager at Sony Mobile, talking at the London launch of the new phablet, said was limited by the size of the connectors.

The 3.5mm jack now almost spans the thickness of the device, making it difficult to get much smaller. An interesting twist, however, is that the 3.5mm jack is now waterproof too, like the Samsung Galaxy S4 Active, so you won't have to use a cover to keep it proofed.

The Sony Xperia Z Ultra will be available globally from September 2013; no word on carriers or pricing just yet.

READ: Sony Xperia Z Ultra pictures and hands-on