Apple is reportedly working to release its iPhone 6 in both 4.7- and 5.5-inch display sizes, with a launch pegged for as early as September.

The company has yet to make an official announcement or confirm ongoing rumors, but it is widely expected to launch its next-generation iPhone with a significantly larger screen. Rumors of two large-screen iPhone models have been doing rounds for quite some time now, and a new report further bolsters such claims.

The latest bits of information come from Japanese business news publication Nikkei, which claims that the iPhone 6 production cycle is already ramping up. Component makers are reportedly developing parts such as fingerprint sensors and LCD driver chips already, while LCD mass production is set to kick off in the quarter from April to June.

"Suppliers of LCD panels for Apple's new iPhone will ramp up production soon, in line with a timetable for a worldwide launch as early as September," Nikkei reveals. "Manufacturers have apparently begun making such components as fingerprint sensors and chips for liquid-crystal drivers."

"Mass production of liquid crystal display panels will start as early as the April-June quarter at Sharp's Kameyama factory, Japan Display's Mobara plant, and elsewhere, according to sources. LG electronics will supply panels as well. The new handset's display resolution is expected to be significantly higher than that of current models."

In other words, the new iPhone 6 could launch with Ultra Retina displays designed to keep the pixel density high despite the increase in screen size.

The latest report from Nikkei falls in line with previous claims regarding the next-generation iPhone. Both Bloomberg and the Wall Street Journal have previously reported earlier this year that the iPhone 6 would come in two large-screen versions.

Moreover, Nikkei also proved to be accurate with its predictions last year, when it revealed that Apple would launch its iPhone 5S and iPhone 5C models on Sept. 20 in Japan. The date proved to be spot on, as Apple launched its current iPhone lineup precisely on Sept. 20 in the country.

The publication believes that Apple will follow a similar launch schedule this year and will unveil its new-generation iPhone 6 sometime in September.

Keep in mind, however, that nothing is official just yet. All signs point to at least one large-screen iPhone model set to debut this year, but until Apple makes an announcement it's still advisable to take everything with a grain of salt.