Updated contract terms.

Samsung C&T / Single Sales and Supply Contract Execution / (2026.09.18) Single Sales and Supply Contract Execution Correction Notice (Report)

Correction Date: 2026-09-18

1. Disclosure Document Subject to Correction Single Sales and Supply Contract Execution

2. Submission Date of Disclosure Document Subject to Correction 2020.09.21

3. Reason for Correction Change in contract amount and period

4. Correction Details Correction Item | Before Correction | After Correction 2. Contract Details - Contract Amount (KRW) | 1,295,873,938,920 | 1,333,126,655,850 2. Contract Details - Percentage of Sales (%) | 4.21 | 4.33 5. Contract Period - End Date | 2026-10-31 | 2027-08-31

9. Other Material Matters Related to Investment Decisions ※ Previous disclosure contract amount: approximately 1,210.0 billion KRW. ※ Previous disclosure contract amount: approximately 1,295.9 billion KRW.

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Single Sales and Supply Contract Execution

1. Sales and Supply Contract Classification Construction Project Bid

Contract Name: Saewul Nuclear Power Plant Units 3 and 4 Main Equipment Construction Project

2. Contract Details Contract Amount (KRW): 1,333,126,655,850 Recent Sales (KRW): 30,761,501,059,039 Percentage of Sales (%): 4.33 Large Corporation Status: Applicable

3. Contracting Party Korea Hydro & Nuclear Power Co., Ltd. Relationship with Company: -

4. Sales and Supply Region Ulsan Metropolitan City, Ulju County, Seosaeng-myeon, Sinam-ri area

5. Contract Period Start Date: 2015-12-01 End Date: 2027-08-31

6. Major Contract Terms Deposit and Advance Payment: None Payment Terms and Conditions: -

7. Contract (Bid) Date 2020-09-21

8. Disclosure Reservation Related Content Reason for Reservation: - Reservation Period: -

9. Other Material Matters Related to Investment Decisions -

Project Overview: Construction of Saewul Nuclear Power Plant Units 3 and 4 (1,400MW × 2 units)

The above contract is a change order to the initial contract executed with Korea Hydro & Nuclear Power Co., Ltd. on 2015.06.12, titled "Shin-Kori Nuclear Power Plant Units 5 and 6 Main Equipment Construction Project" (approximately 600.6 billion KRW, representing 2.11% of the consolidated sales of the former Samsung C&T as of the end of 2014).

※ Previous disclosure contract amount: approximately 1,295.9 billion KRW. ※ On 2022.11.23, the contract name "Shin-Kori Nuclear Power Plant Units 5 and 6 Main Equipment Construction Project" was changed to "Saewul Nuclear Power Plant Units 3 and 4 Main Equipment Construction Project."

The contract amount in Section 2 above represents the Company's portion of the total contract amount and includes the existing contract amount and value-added tax.

The contract period in Section 5 above is the construction period.

The construction period, contract amount, and other terms may change in the course of project execution.

※ Related Disclosures: 2020-09-21 Single Sales and Supply Contract Execution 2021-08-25 Single Sales and Supply Contract Execution 2021-12-16 Single Sales and Supply Contract Execution 2022-01-13 Single Sales and Supply Contract Execution 2022-07-22 Single Sales and Supply Contract Execution 2022-11-23 Single Sales and Supply Contract Execution 2023-04-11 Single Sales and Supply Contract Execution 2023-06-30 Single Sales and Supply Contract Execution 2023-12-28 Single Sales and Supply Contract Execution 2024-05-14 Single Sales and Supply Contract Execution 2024-09-30 Single Sales and Supply Contract Execution 2024-12-24 Single Sales and Supply Contract Execution 2025-11-21 Single Sales and Supply Contract Execution 2025-12-19 Single Sales and Supply Contract Execution 2026-01-30 Single Sales and Supply Contract Execution