New York, New York and HSINCHU, Taiwan, September 4, 2006 - UMC (NYSE: UMC; TSE: 2303), a leading global semiconductor foundry, today announced that it has received the "Outstanding Risk Management Performance Award" from American International Group, Inc. (AIG), a world leader in insurance and financial services and one of the top three companies ranked in the Forbes Global 2,000. The award demonstrates UMC's positive corporate image worldwide and underscores the company's achievements in risk management and damage prevention. In the area of risk management, UMC has already received the National Sustainable Development Award from the Executive Yuan and the Gold Medal at the National QCC Awards from the Ministry of Economic Affairs.

UMC addresses risk through measures such as maintaining modern fire fighting facilities, performing earthquake risk evaluation, and engaging the services of EQE, an engineering consulting firm specializing in earthquake risk. All UMC fabs conform to the necessary earthquake protection measures prescribed in the 1997 Uniform Building Code/Zone 4 Requirements. UMC is pursuing the goal of HPR (Highly Protected Risk) status in the semiconductor industry through the implementation of strict engineering safety procedures, regular enforcement of safety codes and standards, and following detailed industry safety guidelines.

Risk and safety issues are administered by the Group Risk Management Division, which was established in 1997. Activities include promoting a culture of safety within the organization and equipping each fab with BCP to lower the risk of production breakdown. UMC's professionally trained Fire Brigade is on duty 24-hours a day and is armed with state-of-the-art equipment to provide services for UMC as well as other local companies. Its self-developed mobile smoke discharging system in cleanrooms is also unique to the industry.

UMC fabs have been ranked as top-class following AIG's risk evaluation. Ross Matthews, president of AIG Greater China, will present the Outstanding Risk Management Performance Award during an awards ceremony that will take place at UMC's Headquarters on September 5th.

UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that manufactures advanced system-on-chip (SoC) designs for applications spanning every major sector of the IC industry. UMC's SoC Solution Foundry strategy is based on the strength of the company's advanced technologies, which include production proven 90nm, 65nm, mixed signal/RFCMOS, and a wide range of specialty technologies. Production is supported through 10 wafer manufacturing facilities that include two advanced 300mm fabs; Fab 12A in Taiwan and Singapore-based Fab 12i are both in volume production for a variety of customer products. The company employs approximately 12,000 people worldwide and has offices in Taiwan, Japan, Singapore, Europe, and the United States. UMC can be found on the web at http://www.umc.com.