We might just see the advent of large screen smartphones from Apple beginning later this year as reports emerge that the tech giant is seriously considering the global release of a 4.7-inch iPhone 5S and a 5.7-inch iPhone 6.

Citing an anonymous source, Reuters reported on Thursday that tests are now underway for the likely development of the next-generation iPhones and the company is now in the process of active discussion with its supply chain partners on the matter.

These activities will likely produce three iPhone models - two of them to be launched later this year and will go by the name iPhone 5S and the iPhone Mini, also known as the budget iPhone geared for a mass market release.

"For this year (2013), Apple is expected to launch two new models, widely referred to as the iPhone 5S, with new fingerprint technology, and a cheaper version in plastic casing, supply chain sources have said," the Reuters report said.

While the configuration of the cheaper iPhone has been largely determined, it appears that screen size for the 5S and the iPhone 6 is yet to be defined as Apple puts to test the real-world functionalities of giving them over-stretched screen plus Retina display technology.

Should the report proved true, it is a radical departure from Apple's iPhone template, with company big boss Tim Cook earlier insisting that optimal smartphone experience is more realistic within the 4-inch screen display.

Beyond this feature, the technology will suffer severe trade offs, the Apple CEO stressed.

The move, however, makes sense as experts pointed to the glaring adjustments made by Apple engineers with the recently unveiled iOS 7, which they claimed now flashes features and functions optimised for big-screen smartphones.

Also, coming up with a 4.7-inch iPhone and a 5.7-inch iPhone will surely shake the current smartphone industry equilibrium, with most of the impact to be felt by Samsung's 5-inch Galaxy S4 and the soon-to-be unveiled 6-inch Galaxy Note 3.

Battling the two top Android handsets with near-sized iPhone rivals will likely halt the incredible surge that Samsung has been seeing, beginning with the rollout of the GS4 earlier this year. The Galaxy flagship already delivered more than 10 million in global sales for Samsung.

Apple is expected to debut the iPhone 5S between September and October this year while the bigger iPhone 6 is pegged by analysts for a Q1 2014 release date.