O2 is one of a score of operators to have licensed i-mode technology from its creator and owner, Japan’s NTT DoCoMo, launching a mobile internet service to rival the WAP-based ones from the likes of Vodafone and France Telecom’s Orange division.

The service debuts in the UK with 100 sites in operation from content providers as varied as Sony BMG and Bloomberg (the latter’s first foray into mobile content delivery in the UK).

These are, of course, only the official i-mode sites, which pay a 14% commission to O2 on each content transaction carried out (compared to an estimated 40% charged by Vodafone on the Vodafone live! portal), in exchange for which O2 handles their billing.

O2 will hope to see, and indeed will foment, the development of so-called unofficial sites, such as those from retailers that write to the i-mode API but bill under their own steam and pay nothing to the carrier. The importance of these sites is to broaden the overall offering: Japan has some 80,000 i-mode sites, only 4,000 of which are official.

As for handsets, the service debuts with two from NEC and two from Samsung, but Grahame Riddell, head of the i-mode initiative at O2, said phones are scheduled from LG, Sony Ericsson, Nokia and Motorola in the coming months.