The open source offering called Tizen, based on the Linux operating system, is expected to be installed on telephones sold from the end of March, NTT Docomo spokesman Jun Otori told AFP.
Tizen is the product of a tie-up among companies from Japan, China, South Korea, Europe and the United States and comes despite tensions among the Asian neighbours over territorial disputes.
"Unlike Android and iOS, Tizen allows us to develop freely whatever we envision because it is an open-source operating system," said Otori.
Open-source operating systems are not proprietary.
Japanese mobile phones once led the world with cutting-edge technologies such as Docomo's i-mode, the world's first mobile web service, and software including electronic payment systems.
But their glory faded quickly with the emergence of Apple's iPhone, as their concentration on catering to the quirks of domestic consumers saw them diverge from the rest of the world, a phenomenon dubbed "Galapagos Syndrome".
"With Tizen, we hope to revitalise Japanese-developed services and create new services more freely," Otori said.
Tizen is among a handful of new smartphone platforms expected to become available this year, challenging the stranglehold of the two market leaders, Android and iOS.
Phones using operating systems based on the open-source platforms Linux and Mozilla's Firefox will be hitting the market this year, most likely in emerging markets.
Samsung's Tizen-equipped smartphone was likely to be unveiled next month around the time of the industry-wide exhibition Mobile World Congress in Barcelona, Spain, Japan's Mainichi Shimbun said Wednesday.
Samsung will put a Tizen smartphone on the market as early as this spring, the daily said, citing unnamed industry sources.
Separately, NTT Docomo, China's number two carrier China Mobile and South Korea's second-largest carrier KT are planning to share their mobile networks using high-speed LTE technology this year, in a bid to internationalise their businesses, the Mainichi said.The reported move comes against the backdrop of rising cross-border business and tourism, and Docomo expects the planned cooperation to help stimulate the Asian market, it said