Sony Xperia Z Ultra official with 6.4-inch 1080p screen. Source: SONY

New phablet sized handset expands the Xperia range and challenges Samsung's Note series

Expanding its well-received Xperia range and aiming to unseat Samsung’s grip on the phablet market, Sony have announced the launch of the world’s slimmest largest (but not slimmest slimmest) smartphone: the 6.4’’ Xperia Z Ultra.

The new Ultra is bigger even than Samsung’s Galaxy Mega – a 6.3’’ handset announced earlier this month. A study by Transparency Market Research has said that Samsung accounted for 70% of the “superphone and phablet” market in 2012. With the Ultra Sony are looking to snatch some of these sales back.

At 6.5mm thick the Ultra is only slightly larger than the thinnest device on the market – Huawei’s newly announced Ascend P6, which measures only 6.18mm deep. Sony plans to put the Ultra on sale in selected Asian regions in July, before bringing it to Europe in September.

Like its little brother, the Xperia Z, the Ultra is also waterproof, but has improved upon the previous Xperia iteration. Unlike the original Z the Ultra does not need users to plug its headphone socket to protect it from water, and it can be submerged in deeper water (up to 1.5m) for up to half an hour.

And in terms of technical specifications the Ultra is similarly impressive with a 1080p screen, a 2.2GHz quad-core Snapdragon 800, 4G LTE connectivity and 16GB built-in storage (11GB which is user accessible).

There’s also an eight megapixel camera on the back (and a 2mp one on the front), NFC technology and a slightly-heftier-than-normal weight of 212 grams. The Ultra also expands upon normal stylus-only compatibility, with users able to input notes and sketches with “any pencil or selected stylus or pen.”

There’s been no word of price as yet, but the UK version will come with a free £21 voucher to use in Sony’s move, music, and mobile stores, as well as a month’s free access to Music Unlimited – Sony’s on-demand streaming service with over 15 million songs.

Previews of the Ultra so far have been positive, with Aloysius Low at CNET giving a positive verdict of a prototype model, stating he was “impressed with the build quality”, that it was “surprisingly comfortable to hold with one hand” and that the screen was “stunning.”

And for those that consumers that are still (rightly) worried about how they look when actually making a call on such a device, Sony are also pushing the phone with their latest range of Smart Bluetooth Handsets. These can clip to clothing and come with a small OLED screen for browsing calls, receiving texts, or changing music.

We’ve yet to see more details regarding Samsung’s latest phablet – the upcoming Galaxy Note III – but it seems that they’re facing stiff competition from Sony, as their Xperia range really begins to come into its own.