Report of Foreign Issuer Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

United Microelectronics Corporation (UMC) filed a Form 6-K report detailing significant transactions in May 2026. The filing includes an announcement regarding the disposal of Novatek Microelectronics Corporation securities, involving the conversion of zero-coupon exchangeable bonds due 2026. UMC sold 1,174,694 shares of Novatek for an average price of 479.8 NTD per share, totaling 563,618,180 NTD. This disposal is expected to impact retained earnings by 386,963,843 NTD, with no impact on net income. The company currently holds 15,269,893 shares of Novatek, representing 2.51% of its holdings. Additionally, the report provides information on the trading and pledging of UMC common shares by its directors, executive officers, and 10% shareholders during May 2026.