Apple Inc., which is expected to launch its next-generation iPhone later this year, has ordered screens from its Asian suppliers that are bigger than the ones used in iPhones since they debuted in 2007, people familiar with the situation said.

Production is set to begin next month for the screens, which measure at least 4 inches diagonally compared to 3.5 inches on the iPhone 4S, the latest phone from Apple, the people said.

The move suggests that the Cupertino, Calif.-based company is trying to make its popular Smartphone more appealing amid intensifying competition from rival Samsung Electronics Co. of South Korea. Samsung, which became the world's biggest cell phone maker in the first quarter, recently unveiled its new flagship Smartphone with a 4.8-inch display, one of the largest Smartphone screens.

Until now, Apple has never changed the size of the iPhone's screen, which has always been 3.5 inches from the first model that debuted in 2007. For the next iPhone, which analysts predict will come out in the fall, 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.