Taipei, Taiwan, R.O.C. - March 23, 2004, - United Microelectronics Corporation (TAIEX: 2303, NYSE: UMC) – , held a meeting of the Board of Directors and Supervisors, at which the Board passed a resolution to buy-back 360 million shares from the open market. This is the seventh stock buy-back program announced by the company. In addition, the Board passed a resolution to grant stock options to its employees. The details for the share buy-back program and employee stock options are as follows:

1. The Seventh Share Buy-back Program
   
   
   1. Purpose of the share buy back: Transfer to employees
   2. Planned buyback period: Between March 24, 2004 and May 23, 2004.
   3. Number of shares: 360,000,000 shares
   4. Target price range for buyback: NT$19.6 to NT$47.5. If the price falls below the lowest range, the company is still authorized to purchase the shares.
   5. The shares will be purchased from the open market.
   6. The number of shares to be bought back is 2.23% of the total outstanding shares of the company.
   7. The company currently holds 198,842,000 shares of its stock from the previous six stock buyback programs.
      
      
2. Employee Stock Options
   
   

1. 1. UMC has granted 33.33 million stock options to its employees at the exercise price of NT $27.9, which equals the TAIEX closing price of UMC common shares on the grant date of March 23, 2004.
   2. The 2003 Options Plan is a follow-up issue to make up the 150 million shares previously approved by the relevant authorities on October 8, 2003. UMC granted 57.33 million stock options on November 26, 2003.
   3. The 2003 Stock Option Plan applies to employees of UMC and its affiliate companies. The number of options issued to an employee will be determined by a number of factors, including seniority, rank, and job performance.
   4. Each option certificate is equivalent to one UMC common share.
   5. The settlement upon the exercise of share options will be made through the issue of new shares.
   6. The options expire on March 22, 2010, 6 years from the grant date. The vesting schedule is as follows: option holders can exercise up to 50% of the options after two years, up to 75% after three years and up to 100% after 4 years. Proceeds received by the Company from exercises are credited to Common Stock and capital in excess of par value.

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, embedded DRAM, and mixed signal/RFCMOS. UMC is also a leader in 300mm manufacturing; Fab 12A in Taiwan is currently in volume production for a variety of customer products, while Singapore-based UMCi has just entered volume production. UMC employs over 8,500 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.