The launch of Apple's iPhone 3G in Japan has been greeted by lines of enthusiastic buyers up to half a mile long, according to local press reports.

The new phone went on sale this morning at 7am at a Tokyo outlet of Apple's local partner, SoftBank Mobile.

Japan's mobile handset market is dominated by local firms like Sharp, Panasonic and Fujitsu which account for more than 90 per cent of sales, according to the Yano Research Institute.

Foreign companies, with the partial exception of Sony's joint venture with Ericsson, have little presence in the Japanese market.

Apple's key advantage over other foreign handset vendors in Japan is that its brand is already fairly well known, thanks to respectable sales of computers and the iPod series.

However, the iPhone's entry into Japan was delayed while Apple developed the 3G version which is the first to be compatible with local networks.

Competitors have downplayed the hype surrounding the launch. Kaoru Yanu, president of competing vendor NEC, told the Asahi Shimbun that the design of the phone and the lack of a numerical keypad would make it hard for Japanese users to operate with one hand as they are used to doing.

Japan's mobile phone market is heavily saturated, with more than 100 million subscribers out of a population of 128 million.

However, the introduction of mobile number portability has made it easier for subscribers to switch operators. Every year, more than 40 million Japanese buy a new handset.

SoftBank is selling the 8GB iPhone 3G to new customers for $215 with a two-year contract. An unlimited data plan costs $55 per month.