General Announcement::Notice to Bonholders for Closed Period for Bond Exchange

Issuer & Securities

Announcement Title: General Announcement
Date &Time of Broadcast: 22-Jun-2026 15:44:50
Status: New
Announcement Sub Title: Notice to Bonholders for Closed Period for Bond Exchange
Announcement Reference: SG260622OTHR9KO5
Submitted By (Co./ Ind. Name): Chitung Liu
Designation: CFO
Effective Date and Time of the event: 22/06/2026 15:30:00
Description (Please provide a detailed description of the event in the box below): NOTICE IS HEREBY GIVEN that Exchange Period in relation to the Bonds shall expire at the close of business (at the place where such Bonds is deposited for exchange) on June 27, 2026, which is the tenth calendar day prior to the Maturity Date. In addition, Novatek announced a cash dividend of NT$23.0 per common share on June 22nd, 2026 and the register will be closed from July 14th, 2026 to July 18th, 2026. Such declaration of dividends was approved at a general meeting of the Novatek s shareholders held on May 29th, 2026 before such dividends were legally made.

As a result, UMC informs the holders of the Bonds that a Closed Period (as defined in the Indenture) will be in effect during the period between June 23, 2026 to July 7, 2026, and the last Exchange Date is June 22, 2026.

Total size =984K