Japan has been at the forefront of high-speed mobile services

The handsets, due for early 2005 launch in Japan, are aimed at business users, and will boost Motorola's presence in the Japanese market.

The phones will work on high-speed 3G networks, and GSM/GPRS networks - making them operational outside Japan.

The sets will come in a shape similar to personal digital assistants (PDAs).

The tie-up should provide DoCoMo with bargaining strength in price talks with existing Japanese suppliers.

If the move is a success, it could also benefit Motorola by raising its profile as a 3G handset maker and boosting its global sales.

Japan represents less than one-tenth of global mobile phone demand, but is highly innovative when it comes to high-speed services.

DoCoMo became the world's first mobile operator to launch a commercial 3G service based on the W-CDMA standard in 2001.

The new high-end phones will be capable of providing access to regular web sites and compatible with wireless local area network (LAN) services.