[Amended] Change of largest shareholder

What happened

Oscotec / Change of Largest Shareholder / (2026.07.23)

Amendment Report Amendment date: 2026-07-23 1. Disclosure document being amended: Change of largest shareholder 2. Original filing date: 2026-02-05 3. Reason for amendment: Change of largest shareholder due to inheritance 4. Amendments

Item 1. Change details - Largest shareholder after change - Before: None stated; shares held: None; ownership ratio: None - After: Kim Seong-yeon and 1 other; shares held: 4,765,055; ownership ratio: 12.45%

Item 2. Reason for change - Before: Commencement of inheritance following death of largest shareholder - After: Completion of inheritance following death of largest shareholder

Item 4. Change date - Before: 2026-02-05 / After: 2026-07-15 Item 5. Date of confirmation of change - Before: 2026-02-05 / After: 2026-07-23

Item 6. Other matters relevant to investment judgment - Before: The above item 4 (change date) is the date of confirmation of death of the largest shareholder, Kim Jeong-geun. As the inheritance process is ongoing, the final allocation of shares and details of the new largest shareholder (name, shares held) have not been determined; the company will make an amended or additional disclosure as soon as these are determined. - After: The above item 4 (change date) is the date the inheritance division agreement was completed. The above item 5 (date of confirmation of change) is the date the company confirmed the change through a "report on large shareholding of stocks, etc."

- Change of Largest Shareholder 1. Change details: largest shareholder before change Kim Jeong-geun, shares held 4,763,955, ownership ratio 12.45%; largest shareholder after change Kim Seong-yeon and 1 other, shares held 4,765,055, ownership ratio 12.45% 2. Reason for change: Completion of inheritance following death of largest shareholder - change due to acquisition of forfeited shares: No - lock-up obligation on transferred shares: No 3. Purpose of equity acquisition: None stated - source of acquisition funds: own funds: None; borrowed funds: None; lender: None; borrowing period: None; collateral: None - plan for appointment/dismissal of executives after acquisition: None stated 4. Change date: 2026-07-15 5. Date of confirmation of change: 2026-07-23 6. Other matters relevant to investment judgment: the above item 4 (change date) is the date the inheritance division agreement was completed; item 5 (date of confirmation of change) is the date the company confirmed the change through a "report on large shareholding of stocks, etc." ※ Related disclosure: 2026-07-23 Report on large shareholding of stocks, etc. (general)

[Detailed breakdown of changes] Kim Jeong-geun - largest shareholder before change - before: 4,763,955 shares, 12.45% - after: None - note: None Kim Seong-yeon - largest shareholder after change - before: None - after: 3,334,768 shares, 8.72% - note: None Choi Eun-sil - special related party of largest shareholder after change - before: None - after: 1,430,287 shares, 3.74% - note: None

[Information on the new largest shareholder (individual)] 1. Basic individual information: Name: Kim Seong-yeon; Nationality: Republic of Korea - executive career history: None - history as largest shareholder of a listed company: None 2. Relationship between the listed company and the new largest shareholder (individual): None 3. Transactions between the listed company and the new largest shareholder (individual) in the past 3 years (excluding ordinary transactions): current year: None; prior year: None; year before that: None