OSAKA -- The Osaka Securities Exchange launched the OptiMark electronic trading system for institutional investors Friday morning, with an inaugural ceremony attended by top OSE officials.

The new trading system is a completely automated exchange where sell and buy orders are executed automatically by the exchange's computer network.

Dealers say institutional investors favor such an automated system since it would avoid any leakage of insider information that might occur under manually executed transactions.

Stock prices are sometimes subject to fluctuations in reaction to massive orders placed by trust funds and other institutional investors.

"We set up the system in response to the diversified needs of investors," OSE President Goro Tatsumi said. "With the OptiMark system, we believe the OSE will become more convenient."

Trading on the OptiMark system officially got under way with an initial listing of 30 major companies, including Osaka-based Matsushita Electric Industrial Co.

OSE officials said the listing will cover all companies traded on the exchange, including Nasdaq Japan, by February.