Apple Inc is developing new iPhone designs including bigger screens with curved glass and enhanced sensors that can detect different levels of pressure, Bloomberg reported on Sunday, citing a unnamed person familiar with the plans.

With screens of 4.7 inches and 5.5 inches, the two new models would be Apple's largest iPhones, the person told Bloomberg.

The new handsets are still in development and plans haven't been completed, Bloomberg said citing the person, adding Apple probably would release them in the third quarter of next year.

Natalie Kerris, a spokeswoman for the Cupertino, California-based technology company, declined to comment.