South Korean tech company Pantech has unveiled Vega No 6, the biggest smartphone to date with a screen capable of showing 1080p HD video at full resolution.

Pantech’s Android-powered Vega No 6 features a 5.9 in (15 cm) display, which packs in 373 pixels per inch.

China’s Huawei recently unveiled a 6.1 in handset, but it was only a 720p display.

They add to the so-called “phablet” category, as manufacturers test how big customers are willing to go.

When Samsung pioneered the format with its 5.3 in Galaxy Note in 2011, many analysts suggested its size was too large to find favor.

But it proved a success for the firm, leading Samsung to announce a larger successor last August.

Pantech has unveiled Vega No 6, the biggest smartphone to date with a screen capable of showing 1080p HD video at full resolution

In recent months other firms, including Sony, LG, HTC and ZTE, have unveiled smartphones with 5 in and larger screens. More super-sized handsets are expected to be announced at the Mobile World Congress in Barcelona which begins on February 25.

Technology consultancy Ovum suggested that demand for the format was proving particularly strong in emerging markets where most customers could not afford both a phone and a tablet.

“The Galaxy Note has been a proof-point that consumers will adopt the larger phone,” said the firm’s researcher Adam Leach.

“It’s an artificial barrier that a phone has to be below 5 in and a tablet above 7 in.

“There is a limit on what can be used with one hand, but there’s an economic point that if a device can be used like a tablet and a phone then it’s got more value, especially to people who can only afford to buy one device.”

The popularity of phablets is taking some manufacturers in unexpected directions.

Taiwan’s HTC recently announced it would bundle a bluetooth remote control with its 5in-screened Butterfly handset in China.

The add-on HTC Mini has its own screen and can be used to make calls or send messages when paired with the larger phone.