The highly rumored 12.9-inch iPad model has been reportedly delayed until September due to production problems involving the supply of display panels, according to media reports. Production on the bigger tablet had been scheduled to begin this quarter, Bloomberg reported, citing people familiar with the company's plans.

Apple suppliers have been told to start production of the larger-screen iPad in the second half of this year, the Wall Street Journal reported.

Existing suppliers to Apple include Sharp, Japan Display and LG Display.

Among the new featues of the new iPad include faster USB ports as well as ports to connect to a keyboard and mouse, the Journal report said.