Both the WSJ and Reuters are reporting that they have heard from manufacturers that screen orders have come in from Apple for displays “which measure at least 4 inches diagonally” for the iPhone5.

Apple is working with multiple screen makers including South Korea’s LG Display Co., Japan’s Sharp Corp. and Japan Display Inc., a new company created last month by three Japanese companies and the government, some of the people said.

The move indicates that Apple is recognising and responding to the trend toward larger screens, with devices like the Samsung Galaxy S3 (4.8 inch screen) and the HTC One X (4.7 inch screen) setting the bar, and even devices like the Galaxy Note are proving far more popular then many expected.

If correct, this size increase will need to be managed well by Apple so that the existing ecosystem of Apps are unaffected.