Merger decision (subsidiary)

What happened

Report on material management matter of subsidiary SK Advanced Co., Ltd.

1. Merger method SK Gas Co., Ltd. will absorb SK Advanced Co., Ltd. (small-scale, simplified merger)

2. Purpose of merger To strengthen the competitiveness and operating efficiency of the PDH business and generate financial synergies by integrating SK Gas's propane value chain.

3. Merger ratio 0.0000000

4. Basis for calculating the merger ratio SK Gas Co., Ltd., the surviving company, owns 100% of the shares of SK Advanced Co., Ltd., the company to be dissolved, as of the merger date, and since no merger shares will be issued for the dissolving company's shares in the merger, the merger ratio was calculated as 1.0000000 : 0.0000000. - Corporate value: surviving company -, dissolving company -

5. Type and number of new merger shares (shares) Common shares: -, preferred shares: -

6. Counterparty to the merger Company name: SK Gas Co., Ltd. Main business: Wholesale of gaseous fuel and related products Relationship with the Company: Largest shareholder Most recent fiscal year financial details (KRW million): Total assets: 8,031,886 Capital: 46,226 Total liabilities: 4,887,337 Revenue: 7,676,319 Total equity: 3,144,549 Net income: 233,819

7. Newly incorporated merger company Company name: - Financial details at formation (KRW million): total assets -, total liabilities -, total equity -, capital - - Current new business segment: most recent fiscal year revenue (KRW million) -, main business -

8. Merger schedule Expected general shareholders' meeting date: - Old share certificate submission period: start -, end - Creditor objection period: start 2026-10-02, end 2026-11-03 Merger date: 2026-11-04 Expected merger registration date: 2026-11-05 Expected date of delivery of new share certificates: -

9. Appraisal rights As this proceeds under the small-scale merger procedure of Article 527-3 of the Commercial Act, shareholders of SK Gas Co., Ltd. are not entitled to appraisal rights.

10. Board resolution date (decision date): 2026-08-26 - Outside directors present (persons): 4, absent (persons): - - Attendance of auditor (audit committee member who is not an outside director): -

11. Future plans for corporate restructuring As of the date of this report, there are no confirmed plans for corporate restructuring currently being pursued or planned following completion of this merger.

12. Other important matters relevant to investment decisions 1) Since this merger of surviving company SK Gas Co., Ltd. is conducted as a small-scale merger under Article 527-3 of the Commercial Act, shareholders of SK Gas Co., Ltd. are not entitled to appraisal rights, and the general shareholders' meeting for approval of the merger is replaced by board approval. However, if shareholders holding 20% or more of SK Gas Co., Ltd.'s total issued shares notify in writing their opposition to the merger within two weeks of the small-scale merger announcement date, the merger cannot proceed as a small-scale merger. 2) For the dissolving company SK Advanced Co., Ltd., this constitutes a simplified merger under Article 527-2 of the Commercial Act, so shareholders' meeting approval is replaced by board resolution. As of the date of this report, 70.0% of the shares of the company to be absorbed are held by surviving company SK Gas Co., Ltd., and the remaining 30.0% by SK Gas International Pte. Ltd., SK Gas Co., Ltd.'s wholly owned subsidiary; under the merger agreement's conditions precedent, SK Gas Co., Ltd. will acquire the entire issued share capital before the merger date. Accordingly, there are effectively no minority shareholders to exercise opposition, so no procedures for receiving opposition notices or exercising appraisal rights are involved. 3) As this merger falls under the proviso of Article 176-5, Paragraph 8, Item 2(b) of the Enforcement Decree of the Financial Investment Services and Capital Markets Act (where a company owning the entire issued shares of another company merges with that company without issuing new shares), the evaluation by an external appraisal institution is omitted, and accordingly the "corporate value" basis for the merger ratio above is omitted. 4) The "6. Merger counterparty - most recent fiscal year financial details" above are based on the financial statements as of the end of 2025. 5) The "8. Merger schedule" above is the expected schedule as of the date of submission of this report, and may change due to permits, approvals and consultations with relevant authorities under applicable laws. 6) The "closing report general meeting date" in "8. Merger schedule" above will be replaced by board resolution and announcement pursuant to Article 526, Paragraph 3 of the Commercial Act.

Related disclosure: 2026-08-26 Merger decision Related disclosure regulation: Financial Investment Services and Capital Markets Act

[Matters concerning the subsidiary] Subsidiary name: SK Advanced Co., Ltd. English name: SK Advanced Co., Ltd. - Representative: Kim Han-jo - Main business: Manufacture of basic petrochemical chemicals - Whether it is a major subsidiary: Applicable Total assets of the subsidiary (KRW): 939,256,434,782 Total consolidated assets of the parent company (KRW): 8,031,885,593,897 As % of the parent company's total consolidated assets: 11.69