Apple is preparing to launch its next iteration of iPhone devices with 4.7-inch and 5.5-inch screen sizes as early as September.

Apple Inc., the second largest smartphone maker in the world, is reportedly readying itself to launch the next iPhone smartphones with bigger screens in September. The production of two devices with 4.7-inch and 5.5-inch LCD panels is underway and will begin in the April-June quarter. The purported iPhone 6, which will come in two variants, will be a major shift in the company's traditional 4-inch screen offering.

According to a report by Japanese business news publication Nikkei, manufacturers have already commenced the production of key components such as fingerprint sensors and LCD driver chips. These features will reportedly be used in the new devices.

Several reports hinted at an upgrade in iPhone's screen size, in addition to a higher pixel density for larger screens. An earlier report last month showed a leaked image of a rear casing panel of the rumored iPhone 6. The image suggested a larger, thinner and round-edged smartphone is in the works. Other reports also hinted at a bezel-free iPhone 6 with sapphire glass display, adding to the durability and light weight of the device.

With so many rumors spinning around the iPhone 5S successor, the latest report by Nikkei sits on the top of the pile. It echoes previous speculations that have been around for almost two months. All major news sites including Bloomberg and the Wall Street Journal have also pointed towards two larger phones under development by Apple. Larger screen size will also call for an improvement to the device's screen resolution, the report says. Apple will most likely include Full HD resolution displays in its next iPhone.

Nikkei has a well-supported background with regards to iPhone-related rumors. When Apple still hadn't confirmed the launch of its iPhone 5S and 5C, the paper speculated the launch date in Japan to be September 20, which was exactly when the devices were unveiled, TechCrunch reports.

Sources have also confirmed to Nikkei that the LCD panels of the device in the making will be manufactured at the Sharp's Kameyama factory, Japan Display's Mobara plant. Reports also have it that LG Electronics will participate in the making of the device.

Only time can tell if these rumors should be taken with a pinch of salt or be trusted.