TOKYO - KDDI Corp, Japan's second-biggest mobile phone operator, on Tuesday unveiled the world's thinnest folding phone handsets, which it plans to market to older fashion-conscious men.

KDDI's year-end lineup of eight phones includes credit card-sized phones 9.9 millimetres thick when folded, dubbed 'Gold Card', 'Black Card' and 'Platinum Card', which it displayed alongside an array of neckties and suits.

Japanese men in their 40s and 50s, who in previous generations typically received monthly allowances from their wives, have been spending more money and growing more fashion-conscious. That has spurred Tiffany & Co to open a men's jewellery boutique and department store chain Isetan Co Ltd to create a 'men's building' both in Tokyo, among others.

For its part, KDDI, which competes with NTT DoCoMo Inc and Softbank Corp , is looking for ways to lure subscribers in Japan's nearly 9 trillion yen (S$112.8 billion) mobile market, over 50 per cent controlled by DoCoMo.

'Men are more interested in buying ultra-slim mobile phones than women,' KDDI Senior Vice President Makoto Takahashi said in a news conference to unveil the Toshiba Corp-made handsets.

KDDI is also expanding its lineup of phones using organic light-emitting diode (OLED) panels, for crisper digital broadcasts, which are popular among men in their 40s and 50s. -- REUTERS