Fibre optic network connections are now the most popular high-speed internet access method for customers of Japan's largest ISP, according to local press reports.

Over six million subscribers to Nippon Telegraph and Telephone (NTT) broadband internet services were using fibre optic links by the end of March, surpassing the number using slower ADSL links for the first time. 

NTT now has 5.32 million ADSL customers, a drop of 360,000 over the past year, reported the Asahi Shimbun newspaper. 

Japan is estimated to have a total of more than 26 million broadband internet subscribers.

The fibre optic links provide data speeds at least two times higher than conventional ADSL or ADSL2+.

Japan's fibre optic links currently offer speeds up to 100Mbps and, unlike ADSL, do not show a pronounced fall in bandwidth over intra-city ranges.

Home fibre internet subscribers in the country will increase by an average of more than three million a year to exceed 27 million by 2011, according to Tokyo-based consulting firm the Yano Research Institute. 

NTT aims to increase its fibre optic user base to 30 million by 2010, and is strongly promoting high-resolution video and low cost VoIP phone services over the high speed lines.

Some 60 to 70 per cent of new customers at major fixed-line telecoms carriers have been simultaneously signing up for an optical fibre-based internet phone service, Yano Research reported late last year.

The companies are attracted in part by lower basic monthly fees than for a combined ADSL and conventional analogue phone package.