9958 Century Steel Announces Board Resolution to Acquire Equity via Subsidiary Share Conversion

Release Date: June 26, 2026 Statement Date: June 25, 2026 Statement Time: 16:34:49 Company Code: 9958 Company Name: Century Steel Subject: Announcement of Board Resolution to Acquire Equity from Related Party Due to Subsidiary’s Share Conversion Applicable Clause: Clause 20 Factual Date: June 25, 2026

1. Name and Nature of the Subject Asset (if preferred shares, specify issuance terms such as dividend rate): Name of Asset: Century Offshore Wind Power Equipment Co., Ltd. Nature of Asset: Common Shares

2. Factual Date: June 25, 2026 ~ June 25, 2026

3. Board Approval Date: June 25, 2026 (Minguo Year 115)

4. Other Approval Dates: Not applicable

5. Transaction Quantity, Unit Price, and Total Transaction Amount: Transaction Quantity: 92,908,568 shares of Century Huaxin Wind Energy Co., Ltd. (hereinafter referred to as “Century Huaxin”) held by the Company will be exchanged as consideration for 20,439,884 newly issued shares of Century Offshore Wind Power Equipment Co., Ltd. (hereinafter referred to as “Century Wind”). Unit Price: 0.22 new shares of Century Wind for each share of Century Huaxin. Total Transaction Amount: The transaction is settled in shares. Based on the closing price of Century Wind’s stock on June 17, 2026 (NT$175), the total value is NT$3,576,980 thousand, which serves as the basis for this announcement.

6. Counterparty and Its Relationship with the Company (if the counterparty is a natural person and not a related party, name disclosure may be omitted): Counterparty: Century Wind Relationship with the Company: A significant subsidiary of the Company

7. If the counterparty is a related party, disclose the reason for selection, previous transferor, relationship among the previous transferor, the Company, and the counterparty, transfer date, and transfer amount: Reason for Selection: The Company considered the overall strategic synergy of group development and the long-term operational needs of subsidiaries Century Wind and Century Huaxin, and proceeded in accordance with the relevant regulations on asset acquisition and disposal procedures. Previous Transferor: Not applicable (acquired through share exchange for newly issued shares) Relationship among Previous Transferor, Company, and Counterparty: Not applicable

8. If the ownership of the subject asset was held by a related party of the Company within the past five years, disclose the acquisition and disposal dates, prices, and relationship with the Company at the time: Not applicable

9. Matters related to the disposal of receivables (including types of collateral, and if receivables from related parties, disclose the name and book amount): Not applicable

10. Gain (or loss) from disposal (not applicable for acquisition of securities) (if previously deferred, explain recognition): Not applicable

11. Delivery or payment terms (including payment period and amount), contractual restrictions, and other important agreements: Delivery or Payment Terms: To be executed according to the share conversion agreement between Century Huaxin and Century Wind. Contractual Restrictions and Other Important Agreements: None

12. Decision-making method of this transaction, reference basis for price determination, and decision-making unit: The boards of Century Huaxin and Century Wind resolved on June 25, 2026 to proceed with the share conversion. Each ordinary share of Century Huaxin will be exchanged for 0.22 ordinary shares of Century Wind. The Company conducted relevant evaluations in accordance with Article 10 of its 'Asset Acquisition and Disposal Procedures,' and obtained an independent expert opinion titled 'Opinion on the Reasonableness of the Transaction Price and Impact on Shareholders’ Interests Regarding Century Steel Structure Co., Ltd.’s Acquisition of Equity in Century Offshore Wind Power Equipment Co., Ltd. and Disposal of Holdings in Century Huaxin Wind Energy Co., Ltd.' The Audit Committee and Board of Directors of the Company have approved the transaction.

13. Net asset value per share of the securities-issuing company (if applicable): Not applicable

14. Cumulative holdings of the securities involved in this transaction (including this transaction) to date: Company (Century Steel) Quantity: 120,942,068 shares Amount: NT$10,069,057 thousand Ownership Ratio: 51.25% Restrictions on Rights: None

Subsidiary (Century Huaxin Wind Energy Co., Ltd.) Quantity: 7,669,797 shares Amount: NT$1,413,666 thousand Ownership Ratio: 3.25% Restrictions on Rights: None

Subsidiary (Century Heavy Industry International Co., Ltd.) Quantity: 978,200 shares Amount: NT$222,000 thousand Ownership Ratio: 0.41% Restrictions on Rights: None

15. Proportion of securities investments (including this transaction) under Article 3 of the 'Regulations on the Acquisition or Disposition of Assets by Publicly Issued Companies' to the Company’s total assets and equity attributable to owners of the parent in the most recent financial statements, and the amount of working capital in the most recent financial statements: Proportion to Total Assets: 7.24% Proportion to Equity Attributable to Owners of the Parent: 31.19% Working Capital in Most Recent Financial Statements: NT$4,506,690 thousand

16. Broker and Brokerage Fees: Not applicable

17. Specific Purpose or Use of the Acquisition or Disposition: Considering the future operational development needs of Century Huaxin and Century Wind, and in accordance with asset acquisition and disposal procedures, on the share conversion benchmark date (tentatively December 31, 2026), the Company will exchange its full holding of 92,908,568 shares in Century Huaxin for 20,439,884 new shares in Century Wind. As a result, the Company’s total holdings in Century Wind will increase from the current 100,502,184 shares (52.34%) to 120,942,068 shares (51.25% post-increase), maintaining its position as the largest shareholder.

18. Dissenting Director’s Opinion on the Transaction: None

19. Is this transaction a related-party transaction? Yes

20. Date of Approval by Supervisors or Audit Committee: June 25, 2026 (Minguo Year 115)

21. Did the accountant issue a non-reasonable opinion? No

22. Name of Accounting Firm: Yuanhe United Certified Public Accountants

23. Name of Accountant: Juan Qionghua

24. Accountant’s Practice Certificate Number: Taiwan Finance Certificate Registration (6) No. 2719

25. Does this involve a change in business model? No

26. Explanation of Business Model Change: Not applicable

27. Transaction Status with Counterparty in the Past Year and Expected in the Next Year: Not applicable

28. Source of Funds: Not applicable

29. Previous Material Information Disclosure Date for the Same Event: Not applicable

30. Other Explanatory Matters: None