UMC Announces Adjustment to Cash Dividend Payout Rate

Date of Announcement: June 24, 2026 Date of Statement: June 23, 2026 Time of Statement: 16:16:16 Company Code: 2303 Company Name: United Microelectronics Corporation (UMC) Subject: Announcement of Adjustment to Cash Dividend Payout Rate Applicable Clause: Clause 14 Date of Fact: June 23, 2026 Details: 1. Date of Board or Shareholders' Meeting Resolution: N/A 2. Previous Dividend Type and Amount: Cash dividend for common shares: NT$32,704,164,009, with a payout of NT$2.60 per share. 3. Revised Dividend Type and Amount: Cash dividend for common shares: NT$32,704,164,009, with a payout of NT$2.60808262 per share. 4. Reason for Change: Due to the company's repurchase of its own shares and the reacquisition of restricted employee stock awards, the number of outstanding common shares and the shareholder dividend payout rate have changed. 5. Other Matters to be Disclosed: According to the board resolution dated June 3, 2026, the Chairman has been authorized to adjust the per-share cash dividend amount.