Tokyo, Japan - September 7, 2006

Yokogawa Signs Partnership Agreement with OSIsoft
– RtPM Platform Adopted to Enhance Total ETS for the Japanese and East Asian Markets –

Yokogawa Electric Corporation has entered into a strategic partnership agreement with OSIsoft, Inc. Under this agreement, Yokogawa will incorporate the OSIsoft Real-time Performance Management (RtPM) Platform technology in the solutions that it provides under the Total Enterprise Technology Solutions (ETS) concept.

This partnership gives Yokogawa the use of a world-leading technology for the real-time operational decision making and enterprise management that is a part of its Total ETS concept. Through Yokogawa, OSIsoft can expand its strategic access to the fastest-growing automation markets in the world.

Yokogawa Information Systems Corporation, a wholly owned subsidiary of Yokogawa, has been an OSIsoft distributor since 1993. As the relationship with OSIsoft has developed into a more comprehensive partnership, Yokogawa can provide OSIsoft's RtPM technology on the basis of its Total ETS. Yokogawa plans to use Total ETS to expand its business beyond traditional IA applications to include enterprise performance management. Also, Yokogawa sees this partnership agreement as an important step toward achieving the goal of being the frontrunner in the global IA market by the year 2010.

Within the context of this partnership agreement, Yokogawa will develop RtPM-based Total ETS business in the IA sector in Japan, China, Korea, and Taiwan. In the Japanese market, the two companies will work closely not only to enhance the localization of RtPM Platform products, but also to provide users with first-line technical support and inquiry response.

About ETS
Enterprise Technology Solutions, or ETS, are a pivotal component of Yokogawa's business concept - the proposal of high-level, comprehensive solutions for all aspects of its customers' corporate activities. ETS addresses every type of issue relating to a corporation's activities, such as the need to increase efficiency by improving productivity and reducing costs.

About the Real-time Performance Management (RtPM) Platform
The Real-time Performance Management (RtPM) Platform, or the RtPM Platform, is a software application that helps optimize operations by collecting and displaying information about plant operations in real time.

About OSIsoft
OSIsoft (www.osisoft.com ) delivers the PI System as the core of its powerful operational data management framework - the RtPM Platform (Real-time Performance Management Platform). The world's leading process manufacturing, life sciences, and utility companies rely on OSIsoft's platform wherever real time data fuels performance. With more than 11,000 installations worldwide, OSIsoft's real time data platform crosses IT and process boundaries to incorporate and display operational information. Providing comprehensive visibility into operations, the OSIsoft platform unlocks the potential for timely analysis and the ability to make critical, informed, and profitable decisions.

Founded in 1980, OSIsoft, Inc. is headquartered in San Leandro, California, USA, with operations worldwide and is privately held.