Apple will most certainly build a phablet-size iPhone 6 and it will be gorgeously thin and light but release date of the giant smartphone will have to wait until early 2015, according to new reports.

From Taiwan's Commercial Business Times and picked up by numerous tech sites, it is alleged that Apple's blueprint for the first iOS phablet calls for an incredibly thin device - its battery supposedly measuring only 2mm in depth.

The same report, according to Apple Insider, speculated that Apple will nickname the larger iPhone as iPhone Air, obviously due to its slimmed down profile and following the naming approach that the company had introduced via the MacBook Air and the iPad Air.

The iPhone Air branding, however, remains unofficial, CNET said in a report, adding that the device may still end up sporting an entirely different name come the unwrapping time.

It appears though that Apple engineers are hell-bent to deliver a giant but sexy smartphone, somehow affirming the report from KGI Securities analyst Ming-chi Kuo that the larger iPhone 6 will have a screaming 5.5-inch viewing window.

Now to achieve the sleek but huge device profile, iPhone designers reportedly thought of further shaving down the standard battery depth ( that is for slim devices) of 3mm. The design is doable but clearly a challenge during the production phase considering that the same power pack will need to supply more battery juice or higher rating from the previous builds.

BGR recalled on its related report that the next-generation iPhone battery will pack some 70 per cent more of operating hours, again per the projections made by Kuo.

So there would be likely delays in the larger iPhone 6 rollout, again as predicted by Kuo's April note to investors. Information from Taiwan indicates that waiting time for the iPhone Air could extend beyond the 2014 Christmas season.

The latest would be in the initial months of 2015.

But 9to5Mac remains upbeat on the likelihood that the iPhone Air will see the light of the day before 2014 draws to a close, noting that "the report (from Taiwan) says that Apple will launch the device as soon as suppliers can produce good yields of the necessary components."

The Apple-centric site hinted as well that even if the 4.7-inch iPhone 6 will enjoy an earlier commercial debut than its bigger sibling, the likelihood is Apple will unveil the two devices simultaneously in September 2014.

And regardless of the separate release dates, the two iPhone 6 builds are expected to showcase premium specs - bannered by a 64-bit A8 chip plus more durable housing thanks to Liquidmetal case and sapphire coating - and killer features stuffed with iOS 8 coming out of the box.