Apple will quit the metal casing design of the future iPhones and will use glass instead, in order differentiate itself in the smartphone market in 2017, said Allen Horng, chairman and chief executive of Apple supplier Catcher Technology. There has been media speculation that the Taiwanese metal casing maker will lose Apple business next year to China's Biel Crystal Manufactory and Lens Technology, which already supplies glass screen covers for iPhones.

"As far as I know, only one [iPhone] model will adopt glass casing next year," Horng told reporters after the annual shareholder meeting on Thursday. "I don't think this move will have an impact on Catcher's revenue as glass casing still needs a durable metal frame which requires advanced processing technology and would not be cheaper than the current model."

Horng said there will be no Apple handsets using glass-only casings without metal frames next year.

Apple is obviously under pressure to improve iPhone sales by making iPhones more distinctive.