"That display is now being manufactured by the supplier's plant in Korea," he added. Its screen will boast an an almost ultra high-definition (UHD) resolution, the report added.
Previously, Taiwan-based Quanta Computer was said to be the maker of the large-size 12-inch iPad.
A Wall Street Journal report in July also claimed that Apple was in the process of testing displays "slightly less than 13 inches diagonally".
In the meantime, Apple rival Samsung Electronics aims to become the world?s biggest tablet supplier.
Samsung Display, a unit of Samsung Electronics, is developing OLED displays sized over 10 inches and 13 inches to be used in Samsung?s upcoming Galaxy-branded tablets next year.