Updated

Apple and its Asian suppliers are testing larger screens for iPhones and tablets, officials at the company's suppliers say.

In recent months, Apple has asked for prototype smartphone screens larger than 4 inches and has also asked for screen designs for a new tablet device measuring slightly less than 13 inches diagonally, they said. The current iPhone 5 has a four-inch screen, while the iPad has a 9.7-inch screen. The iPad Mini, a stripped-down version of its tablet computer, has a 7.9-inch screen.

Whether the designs will make their way to market is unclear. The Cupertino, Calif., company routinely tests different designs for its products as it refines them during development. The company also changed its offerings of the iPhone and iPod last year to include larger screens, while adding a variant of the iPad with a smaller display.

An Apple spokeswoman declined to comment.

The tests with suppliers seem to suggest that Apple is exploring ways to capture diversifying customer needs at a time when many mobile device makers offer smartphones and tablets in various sizes.

Read more about Apple's bigger iPads at The Wall Street Journal.