Nine general trading houses and computer companies have started to jointly develop an open computer network system to exchange trade documents over the Internet, the firms said Monday.

The Trade Electronic Data Interchange project is developing the new system, which will be open to smaller trading companies that do not have their own computer network system.

The project is also intending to simplify trade documents for easier online transfers.

The nine companies plan to start experimental operation of the TEDI system in April in cooperation with financial institutions and transport firms. The member companies plan to launch full-scale operation of the new system next September, they said.

The Ministry of International Trade and Industry is funding the development of the system. The member firms include Mitsubishi Corp., Mitsui & Co., NTT Communications, Hitachi Ltd. and Fujitsu Ltd.