HTC is planning to release a larger version of the One, dubbed the One Max. See also: HTC One review: a fantastic high-end Android smartphone.
Leaked images of the purported device have been published by Twitter account @evleaks.
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The evleaks Twitter account, which has a solid track record when it comes to publishing rumours, describes the image as "non-final artwork".
The device looks like a larger version of the HTC One. It appears to have the same aluminium construction, dual-speakers and non-removable battery as the One, but is expected to have a larger 5.9in screen.
The current HTC One has a 4.7in screen, while the company released the smaller HTC One mini last month with a 4.3in display.
The larger screen means the HTC One Max will be expected to compete directly with the Samsung's popular Galaxy Note range.
It will reportedly come with a 2.3Ghz quad-core Snapdragon 800 processor, 2GB of RAM, and will be powered by a 3300mAh battery.
The One Max will also come with HTC's "UltraPixel" camera. The custom image sensor uses enlarged pixels that the company says can absorb up to three times more light than those inside "most leading 13-megapixel phone cameras."