Apple wanted to release a 4.8-inch iPhone 6 this year, but it ran into manufacturing problems, says Jefferies analyst Peter Misek.
The plan was to release the bigger iPhone at the end of the year (October time frame) prevent market share loss, but Misek reports Apple's screen suppliers are struggling to increase the size of the 4-inch iPhone to 4.8-inches.
Apple's iPhone uses a technology called "in-cell," which essentially meshes the touch screen with the glass screen into one thin display. Its partners can't get good enough yields making those displays bigger to launch the iPhone 6 this year.
If Apple had released the iPhone 6 this year, it would have been the third new iPhone model for the year, according to Misek's roadmap. He says Apple will release a low-cost iPhone in June, as well as an iPhone 5S, which is a slight bump over the current iPhone 5.
Misek believes there is another reason Apple could be holding back on the iPhone 6.
He thinks the next iPhone will run on a 20 nm processor, allowing it to add more cores, possibly four or eight. To take advantage of the new processing speed, iOS will have to be upgraded. The new iOS architecture might not be ready until 2014.