Yesterday we brought you a news that rumors of a 4-inch screen for the iPhone 5 had been confirmed. Sources told the Wall Street Journal that Apple was in talks with three manufacturers to supply displays at least 4-inches on the diagonal to Apple for the next iPhone.

Today, those rumors have apparently been confirmed again. Reuters is reporting that Apple is indeed making preparations to expand the display of the iPhone. Citing “people familiar with the situation,” the report pegs the iPhone display at 4 inches (most rumors have said it would be at least 4 inches, maybe bigger). They also confirm that Apple is in talks with Sharp, LG, and Japan Display to build the screens. The report speculates that Apple will order displays from all three manufacturers in order to speed up production, which may start in August.

Reuters also suggests that the increase in screen size is a response to the increasing screen size of Android-based smartphones, particularly made by Apple’s arch-rival Samsung. While that’s possible, it’s not necessarily true. Apple traditionally prefers to create market trends, rather than following them. Though it’s possible that Apple could be just hopping onto the bigger screen bandwagon, it’s also true that they’ve taken the 3.5-inch screen of the previous five iPhone models about as far as they can. Unless they decide to add haptic feedback or some other new technology to the display, there isn’t much they can do to improve it other than make it a little bigger. They’ve hit what appears to be an upper limit on display resolution, and there are only so many ways you can redesign the body around a 3.5-inch display, so bumping the display size a little is an easy way to make the new phone stand out from its predecessors.

There’s one other major factor, though, that Reuters doesn’t take into account and that is probably a major driving factor in the increase in size. Recall, if you will, that in March Apple debuted a shiny new iPad with only a handful of new features. One of the most notable of those features (apart from the retina display) was 4G. Now, it probably goes without saying, but there’s no way that Apple would launch a 4G iPad in March and then not launch a 4G iPhone in October.

But adding 4G comes with a price – the 4G radios take up more space inside the casing of the device. They’re also power hogs, which means that using your new iPhone on a 4G LTE network will drain your battery a lot faster. Battery life has been one of the chief complaints about the iPhone for years now, with the iPhone 4S being one of the poorest of the bunch in this area. Apple can’t afford to increase the new iPhone’s power consumption and leave the battery as is. And since fuel cells for mobile phones haven’t really caught on, that means making the battery bigger. Extra components plus a bigger battery to power them means that the iPhone itself needs to grow.

With reports of the iPhone’s growth spurt coming from increasingly reputable sources, it’s looking like a sure thing at this point. Nevertheless, we’ve still got a few months to wait until we know for sure. In the meanwhile, there are sure to be some interesting things coming at WWDC 2012, and more information about the next iPhone is bound to keep leaking out. We’ll keep you posted as more information becomes available.

[Lead Image: Concept Photo from ADR Studios]