Sony Corp. has started work on developing a successor to its popular PlayStation2 game console by 2005 with a view to putting it on the market after use of fiber-optic networks becomes widespread, according to Sony sources.

The third-generation PlayStation will feature a powerful micro processing unit roughly 200 times faster than those currently used for video game consoles and personal computers, they said.

Sony Computer Entertainment Inc., a unit of Sony, along with Toshiba Corp. and IBM Corp. plan to spend $400 million developing the MPU, they said.

The next-generation PlayStation will be designed for online use on high-speed fiber-optic networks, making it likely it will be free of memory devices such as DVDs, they said.

Connection to the Internet will place no limits on memory capacity for the envisioned game console, making it possible to play an "endless" game, the sources said.

The newly developed MPU will be capable of processing data at the same speed as supercomputers, enabling users to download video and music data on the Internet and edit and save on a server with specially designed software, they said.

Sony intends to make the new product free of peripherals other than a monitor screen and a game control unit, and has yet to decide whether to use the PlayStation brand name for it, they said.

Sony is considering providing the new MPU to other companies as it is designed for use in TVs and audio equipment as well, they said.

Sony Corp. said last month that shipments of the PlayStation2 game console doubled in fiscal 2001, which ended March 31, from the year before to 18.07 million units.

Shipments of the console since March 2000 totaled more than 28 million units, according to Sony.