Taipei, Taiwan, August 26, 2004 - United Microelectronics Corporation (TAIEX: 2303, NYSE: UMC), a world leading semiconductor foundry, today announced that a plan to acquire UMCi, its 300mmm subsidiary company in Singapore, was approved in the meeting of the Board of Directors. UMC currently own 95.23% of UMCi.

With this acquisition, UMC will recognize revenues and profits from the operations of UMCi's fab and invest capital expenditure for the fab's further capacity expansion. This acquisition will also allow UMC to achieve greater financial transparency. As demand for advanced process technology continues to gain strength, this transaction will also increase the synergy of UMC's overall 300mm fab operations and expansion plans.

Park. UMCi is in full-scale production, and is focused on manufacturing products based on UMC's 0.13um and below technologies. Capacity for the state-of-the-art 300mm automated facility is expected to reach 10,000 wafers per month by the end of 2004.

UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that manufactures advanced process ICs for applications spanning every major sector of the semiconductor industry. UMC delivers cutting-edge foundry technologies that enable sophisticated system-on-chip (SOC) designs, including 90nm copper, 0.13um copper, and mixed signal/RFCMOS. UMC is also a leader in 300mm manufacturing; Fab 12A in Taiwan and Singapore-based UMCi are both in volume production for a variety of customer products. UMC employs over 10,500 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.