Sony unveiled its Xperia Z and the Xperia ZL at the International CES earlier in January this year and it seems these models will soon see a bigger sibling. Recent rumors indicate that Sony may be preparing to launch a 6.44-inch smartphone at the Mobile World Congress (MWC) in February, to rival the upcoming Samsung Galaxy Note S3.

A leaked image of a glass panel for the mystery 6.44-inch Sony smartphone will cover the entire front of the handset. Looking at the glass panel it seems that the device will sport a narrow bezel design while lacking any capacitive navigation buttons. The leaked image of the glass panel also has the Sony logo at the top.

The leaked image is only of the glass panel and does not have a device attached to it. Rumors also indicate that the screen of the alleged 6.44-inch smartphone will have 1080p resolution.

If the leaked image is legit for a Sony Xperia phone in the future, it would make the handset the largest in the smartphone space. The Huawei Ascend Mate measures 6.1-inch with a 720p display, the rumoured ZTE Nubia Z7 has a 6.3-inch 1080p screen, and rumors suggest that Samsung's next phablet will feature a 6.3-inch display.

We have witnessed an increase in smartphone sizes recently and it seems that a 4-inch plus display has become the norm. However, it seems that 2013 will see many smartphones with 6-inch-and-over display sizes.

"We basically are out of the feature-phone business and in the Android-based smartphone business. We are more in toward the high end of the market as opposed to trying to get into the commoditized portion," said Kazuo Hirai, Chief Executive Officer, Sony.

The Xperia Z and the Xperia ZL are due to hit the shelves in Q1 of this year. It will be interesting to see if Sony launches a bigger smartphone at the MWC, even before smartphone users have had the taste of the recently launched Xperia Z and Xperia ZL.