As Sony Corporation prepares to launch its new Xperia Z5 handset sometime next month, another variant, called the Xperia Z5 Plus or Z5 Ultra, is expected to be available as well, according to a recent leak.

The Xperia Z5 Plus/Ultra is rumored to sport a display screen with 4K resolution (3840 x 2160 pixels), according to Techno Buffalo. Inside, reports say there will be Qualcomm's Snapdragon 810 processor.

As of this time, other specs and features for the Xperia Z5 Plus/Ultra still remain unknown, as the recent leak didn't mention anything else aside from the phablet's screen resolution and processor.

The Japanese tech giant is expected to unveil the Xperia Z5 and the Xperia Z5 Compact at the upcoming IFA 2015 event that will take place in Berlin, Germany from September 4 to 9. In terms of availability, there's no information about whether Sony plans to unveil the Xperia Z5 Plus/Ultra at the upcoming IFA event or at a later time.

In comparison, Sony's Xperia Z5 is rumored to sport a 5.5-inch display screen with 1080 x 1920 pixel resolution. Inside, this phone will pack a Qualcomm Snapdragon 810 processor as well, along with 3GB of RAM. In addition, the Z5 is expected to have a very sharp 20.7-megapixel rear-facing camera.

Another new smartphone expected to roll out this month is Sony's Xperia M5. This phone will feature a 5.5-inch display screen with a 1080 x 1920 resolution as well, and will run on Mediatek MT6795 processor along with 3GB of RAM. It will have a slightly higher 21.5-megapixel rear camera, in comparison with the Z5.

Also, according to recent reports, another Sony handset, called the Xperia C5 Ultra, has been rumored to be in the works. As for this phone, there's also no information yet on when it will arrive in the market.