Sony Corp. in April will overhaul its internal company system, elevating its mobile phone division to the rank of a network company and splitting its personal computer division into portable and desktop computer operations, company sources said Wednesday.

The reshuffle is designed to help the consumer electronics giant sharpen its competitive edge in the four fields of digital TV, video game machines, cellular phones and personal computers.

In 1999, the company divided its mainstay operations into network companies, each having the latitude to make decisions about its own investments.

Sony will turn the mobile phone business, now part of the Personal IT Network Company, into a network company on its own right. The greater freedom to make decisions about investments is intended to pave the way for expanding business in third-generation cellular phones as well as overseas.

Meanwhile, splitting the PC operations will create a division that concentrates on notebook computers, personal digital assistants and other mobile terminals.

Sony will also consolidate management of its monitor and projector operations, now separated into commercial and personal markets.

In addition, the communications business division, now part of the Communication System Solutions Network Company, will be placed on equal footing with the robot company, which is responsible for the Aibo robot dog.