[UMC] Board of Directors Resolution to Issue First Domestic Unsecured Convertible Corporate Bond

1. Date of Board Resolution: 2026/06/03 2. Name: United Microelectronics Corp. (UMC) 1st Domestic Unsecured Convertible Bond 3. Shelf Registration: No 4. Total Issuance Amount: Up to NT$12 billion 5. Par Value: Tentatively NT$100,000 per bond 6. Issuance Price: Not less than 101% of par value 7. Term: Tentatively 5 years 8. Coupon Rate: Tentatively 0% 9. Collateral: N/A 10. Purpose: Purchase of machinery and equipment 11. Underwriting Method: Book-building process 12. Bond Trustee: To be determined 13. Underwriting Institution: HungYuan Securities 14. Guarantor: N/A 15. Principal & Interest Agent: To be determined 16. Auditor: N/A 17-21. Conversion terms: Will be announced separately upon approval by regulatory authorities. 22. Reasonableness of fund-raising post capital reduction: N/A 23. Other: Bonds will be issued via book-entry system. Authority is granted to the Chairman to finalize issuance details and application to the Taipei Exchange.