Apple Inc plans to use a larger screen on the next-generation iPhone and has begun to place orders for the new displays from suppliers in South Korea and Japan, people familiar with the situation said on Wednesday.

Early production of the new screens has begun at three suppliers: Korea's LG Display, Sharp Corp and Japan Display Inc, a Japanese government-brokered merger combining the screen production of three companies.

The new iPhone screens will measure 4 inches from corner to corner, one of the sources said.

It is likely all three of the screen suppliers will get production orders from Apple, which could begin as soon as June. That would allow the new iPhone to go into production as soon as August if the company follows its own precedent in moving from orders for prototypes for key components to launch.

Apple's decision to equip the next iPhone with a larger screen represents part of its competitive response to Samsung Electronics. Samsung unveiled its top-of-the line Galaxy smartphone with a 4.8-inch touch screen and a faster processor earlier this month.

Samsung, which this year became the world's largest cell phone maker, sold 45 million smartphones in the first quarter and sales of the Galaxy phones outstripped the iPhone.

Apple was not immediately available to comment.

Apple's move toward a larger display for the next generation iPhone was first reported by The Wall Street Journal.