Taipei, Taiwan, R.O.C. - August 23, 2007 - United Microelectronics Corporation (TAIEX: 2303, NYSE: UMC, or "the Company"), today announces its schedule for 2007 Share Conversion Operations Plan. The shares issued before this capital reduction were 18,952,184,690 common shares. The capital reduction ratio is 30.283357% (302.83357 shares will be reduced per 1,000 shares) and 5,739,357,807 shares will be cancelled. The total issued shares after the reduction will be 13,212,826,883 shares. The book value per share will be changed from NT$16.53 to NT$19.36 after the reduction, which is the pro forma data based on the 2007Q1 financial report.

For common shareholders, the last trading date will be 2007/09/19, the trading suspension period will be from 2007/09/20 to 2007/10/08 and the record date for common shareholders is 2007/09/30. Starting from 2007/10/09, the common share can be traded in the market again. For ADR holders, the record date is 2007/10/08, effective date is 2007/10/09 and there will be no suspension period.

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 volume production 90nm, industry-leading 65nm, and mixed signal/RFCMOS. UMC's 10 wafer manufacturing facilities 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 13,000 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.