Apple's new iPhones head for assembly lines next month: sources

Apple's suppliers will begin mass production of new iPhones in China next month, according to people familiar with the plans of the US smartphone giant.

Apple was ramping up on two bigger-screen iPhones, said the people, who asked not to be identified because the plans are private. One model will have a 4.7-inch screen that may be available to ship to retailers by about September, said two of the people. A larger, 5.5-inch version is also being prepared for manufacturing and may be available at the same time, the people said.

Apple is getting ready for its annual unveiling of new iPhones, with bigger screens beyond the 4 inches of its current iPhone 5s after rivals including Samsung Electronics and HTC released smartphones with displays that are as large as 5.7 inches.

Consumers have been gravitating toward larger-screen devices - in China, 40 per cent of mobile gadgets based on Google's Android operating system that were sold in 2014 had display sizes of more than 5 inches, according to an estimate from Forrester Research.

Apple's iPhone generates more than half of the company's annual revenue. Last year, the smartphone produced US$91 billion in revenue alone, more than the total sales of Oracle, Yahoo!, Facebook and Twitter combined. Apple spokeswoman Natalie Kerris declined to comment.