Material event report (merger)

What happened

Material Event Report / Korea Exchange Reporting Obligation To the Financial Services Commission / Korea Exchange August 26, 2026

Company name: SK Gas Co., Ltd. CEO: Yoon Byung-seok Head office: 332 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do Tel: 02-6200-8114 Website: https://www.skgas.co.kr Preparer: (Title) Head of Finance Office (Name) Choi Yi-ruk (Tel) 02-6200-8114

Company merger decision

1. Merger method SK Gas Co., Ltd. will absorb SK Advanced Co., Ltd. - Surviving company: SK Gas Co., Ltd. - Dissolving company: SK Advanced Co., Ltd. - Merger type: Small-scale merger

2. Purpose of merger To optimize SK Gas's propane business value chain. By integrating SK Advanced, which is connected as a 100% subsidiary as of the merger date, the Company aims to combine propane feedstock procurement competitiveness with PDH business operating competitiveness, raising business efficiency and generating financial synergies.

3. Material effects of the merger (1) Effect on management: The surviving company will be SK Gas Co., Ltd., and SK Advanced Co., Ltd. will be dissolved after the merger. SK Gas Co., Ltd. will succeed to SK Advanced Co., Ltd.'s business as is. As of the date of this report, the largest shareholder of surviving company SK Gas Co., Ltd. is SK Discovery Co., Ltd., holding 71.90%. The shares of dissolving company SK Advanced Co., Ltd. are held 70.00% by SK Gas Co., Ltd. and 30.00% by SK Gas International Pte. Ltd. (SK Gas's wholly owned subsidiary); under the merger agreement's conditions precedent, SK Gas Co., Ltd. will acquire the entire issued shares of SK Advanced Co., Ltd. before the merger date. After completion of the merger, SK Advanced Co., Ltd. will be dissolved by absorption into SK Gas Co., Ltd., which will succeed to all of SK Advanced's rights, obligations and status. (2) Effect on finances and operations: Since SK Advanced Co., Ltd. is already a wholly (100%) owned company of SK Gas Co., Ltd. and its consolidated subsidiaries, the effect of this merger on consolidated financial position and operations is expected to be limited; rather, synergies and improved management efficiency are expected from value-chain integration, including reduced interest expense from a lower funding cost for the absorbed company and reduced duplicate operating costs, improving the financial structure and consolidated cash flow even amid industry fluctuations. (3) Effect on operations: By integrating the business value chain from propane sourcing through petrochemical product production and distribution, the merger is expected to strengthen both companies' operating competitiveness, respond more flexibly to market volatility, speed up decision-making, unify previously dual organizational and operational functions, remove internal inefficiencies, and reduce cost, improving the surviving company's medium- to long-term competitiveness and profitability. (4) Effect on shareholder value: This merger proceeds at a merger ratio of 1:0.0000000 with no new shares issued, so there is no change in existing shareholders' ownership ratio and no structural issue of conflicts of interest between shareholders or unfair benefit to any particular shareholder. Shareholders of surviving company SK Gas Co., Ltd. can expect economic benefits from the financial combination (reduced funding cost of the absorbed company, consolidated profit/loss) and improved cash flow and financial stability from greater market responsiveness and operating flexibility, ultimately enhancing shareholder value for all of the Company's shareholders.

4. Merger ratio SK Gas Co., Ltd. : SK Advanced Co., Ltd. = 1.0000000 : 0.0000000 (merger without capital increase)

5. Basis for calculating the merger ratio As of the date of this report, surviving company SK Gas Co., Ltd. owns 70.0% of the issued shares of dissolving company SK Advanced Co., Ltd., with the remaining 30.0% owned by SK Gas Co., Ltd.'s wholly owned subsidiary SK Gas International Pte. Ltd. Under the merger agreement's conditions precedent, SK Gas Co., Ltd. will acquire the entire issued shares of SK Advanced Co., Ltd. before the merger date. Accordingly, this merger proceeds without issuing new shares, and the merger ratio was calculated as 1.0000000 : 0.0000000. - Corporate value: surviving company -, dissolving company -

6. External appraisal Not applicable. Basis and reason: Under the proviso to 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, an external appraisal institution's evaluation of the appropriateness of the merger value is not required, so this merger was not evaluated by an external appraisal institution. Name of institution: -; appraisal period: -; appraisal opinion: -

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

8. Merger counterparty Company name: SK Advanced Co., Ltd. Main business: Manufacture of basic petrochemical chemicals Relationship with the Company: Subsidiary Most recent fiscal year financial details (KRW): Total assets: 939,256,434,782 Capital: 34,006,600,000 Total liabilities: 754,136,018,148 Revenue: 610,098,449,522 Total equity: 185,120,416,634 Net income: -244,813,278,032 External audit: Hanyoung Accounting Corporation, opinion unqualified; representative, date of incorporation, head office, expected securities registration filing date for a SPAC-dissolution merger: not applicable, -

9. Newly incorporated merger company: all items -; relisting application: Not applicable

10. Merger schedule Merger contract date: August 27, 2026 Record date for determining shareholders: September 10, 2026 Shareholder register closure period: - Period for receiving notices of opposition to merger: September 10, 2026 - September 28, 2026 Expected general shareholders' meeting date: - Appraisal rights exercise period: - Old share certificate submission period: - Expected trading suspension period: - Creditor objection period: October 1, 2026 - November 3, 2026 Merger date: November 4, 2026 Closing report general meeting date: November 4, 2026 Expected merger registration date: November 5, 2026 Expected date of delivery of new share certificates: - Expected listing date of new shares: -

11. Backdoor listing: Not applicable 12. Whether another company's backdoor listing requirements are met: Not applicable

13. Appraisal rights Exercise requirements: As this merger constitutes a small-scale merger under Article 527-3 of the Commercial Act, appraisal rights for dissenting shareholders are not recognized under Article 527-3, Paragraph 5 of the same Act. Expected purchase price: -; exercise procedure, method, period, location: -; expected payment timing and method: -; restrictions on appraisal rights: -; effect on the contract: -

14. Board resolution date (decision date): August 26, 2026 - Independent (outside) directors present: 4, absent: 0 - Attendance of auditor (audit committee member who is not an independent (outside) director): -

15. Put option or similar contracts: No; contract details: -

16. Subject to securities registration statement: No Reason for exemption: As this merger proceeds without issuing new shares, there is no offering or sale of securities, so filing of a securities registration statement is exempted.

17. Future plans for corporate restructuring As of the date of this report, the surviving company has no confirmed plans for corporate restructuring currently being pursued or determined to proceed following this merger.

18. Other important matters relevant to investment decisions a. As this is a merger without capital increase, there is no change in the surviving company's capital after the merger. b. As this merger constitutes a small-scale merger under Article 527-3 of the Commercial Act, appraisal rights for dissenting shareholders are not recognized, and approval of the merger is replaced by board approval under that article. The board meeting scheduled to approve the merger is October 1, 2026 (Thursday). c. If shareholder(s) holding 20% or more of the surviving company's total issued shares notify in writing their opposition to the merger within two weeks of the merger announcement date, the merger cannot proceed as a small-scale merger under Article 527-3, Paragraph 4 of the Commercial Act. d. The "8. Merger counterparty - most recent fiscal year financial details (KRW)" above is financial information as of the end of 2025. e. Under Article 526, Paragraph 3 of the Commercial Act, the merger closing report meeting will be replaced by board resolution and announcement, and the "10. Merger schedule - closing report meeting date" above is the expected date of the board's merger-closing report and announcement. f. The "10. Merger schedule" above is the expected schedule as of the date of submission of this report and may change due to agreement between the merging companies, permits/approvals under relevant laws, and consultation with relevant authorities. The merging companies may also change or terminate the terms of this merger by mutual agreement between the contract date and the merger date.

Related disclosure: None

[Detailed particulars of the merger] 1. Overview of the merger (1) Basic matters a. Merger parties: Surviving company SK Gas Co., Ltd., located at 332 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do (ECO Hub), represented by Yoon Byung-seok, a KOSPI-listed corporation. Dissolving company SK Advanced Co., Ltd., located at 299 Yongyeon-ro, Nam-gu, Ulsan (SK Advanced), represented by Kim Han-jo, an unlisted corporation. b. Purpose of merger: as described in item 2 above. c. Backdoor listing: Not applicable. d. Material effects on management, business, profit/loss and finances: SK Advanced's assets, liabilities, rights and obligations as of the merger date will be succeeded by SK Gas without separate procedures or contracts. As SK Advanced is a 100%-owned, already-consolidated subsidiary of SK Gas, the merger is not expected to have a significant effect on SK Gas's management, business, profit/loss or finances; rather, business synergy and management efficiency from organizational integration, reduced financing costs and operating efficiencies are expected to contribute to the merged entity's improved overall financial structure and more stable cash flow. e. Future restructuring plans: As of the date of this report, SK Gas has no confirmed plans for corporate restructuring currently being pursued or determined following completion of the merger; restructuring of the Ulsan petrochemical industry will continue to be discussed after realizing the integration synergies first. f. Overview of the merger counterparty: see "2. Matters concerning the merger counterparty" below. g. Form of merger: 1) Method - SK Gas Co., Ltd. (merging company) absorbs SK Advanced Co., Ltd. (company to be merged); SK Gas Co., Ltd. survives and SK Advanced Co., Ltd. is dissolved. 2) Small-scale/simplified merger basis - this merger is a small-scale merger for SK Gas Co., Ltd. under Article 527-3 of the Commercial Act, and a simplified merger for SK Advanced Co., Ltd. under Article 527-2; approval for both companies is replaced by board approval. 3) Surviving company's listing - SK Gas Co., Ltd. is currently a KOSPI-listed corporation and will maintain that status after the merger. h. Key merger schedule: Board resolution to enter merger agreement August 26, 2026; announcement of record date for determining shareholders August 26, 2026 (company website and KRX disclosure); submission of material event report August 26, 2026; merger contract date August 27, 2026; record date for determining shareholders September 10, 2026; small-scale merger announcement September 10, 2026; period for receiving notices of opposition to merger September 10, 2026 - September 28, 2026; board resolution approving the merger (replacing shareholders' meeting) October 1, 2026; creditor objection announcement October 1, 2026; creditor objection period October 1, 2026 - November 3, 2026; merger date November 4, 2026; board resolution on merger closing report (replacing shareholders' meeting) November 4, 2026; merger closing announcement November 4, 2026; expected merger registration date November 5, 2026. (The record date for determining shareholders is to determine SK Gas's rights-holding shareholders entitled to express opposition to the small-scale merger; the closing report meeting will be replaced by board resolution and announcement; the schedule may change through agreement between the parties and permits/approvals/consultation with relevant authorities.) i. Securities registration statement: Not applicable; reason for exemption: merger without capital increase. j. Conditions for completion of the merger: see "(4) Investment risk factors" below. k. Regulations or special provisions under relevant law: The merger must comply with creditor protection procedures under Article 527-5 of the Commercial Act and all other Commercial Act and KOSPI listing rule requirements. Business combination reporting is exempted under Article 11 of the Monopoly Regulation and Fair Trade Act as this is a merger between a parent and subsidiary.

(2) Merger value and basis for calculation a. As SK Gas Co., Ltd. owns 100% of SK Advanced Co., Ltd.'s shares as of the merger date and no new shares will be issued, the merger ratio was set at 1.0000000 : 0.0000000. b. External appraisal was not performed, per the proviso to Article 176-5, Paragraph 8, Item 2(b) of the Capital Markets Act Enforcement Decree, as described above.

(3) Merger procedure a. Allotment of new shares: Not applicable. b. Payment of cash consideration: Not applicable. c. Compensation to specific shareholders: Not applicable. d. Merger-related costs: to be handled by agreement between SK Gas Co., Ltd. and SK Advanced Co., Ltd. e. Treasury shares: merging company SK Gas Co., Ltd. holds 235,198 treasury shares as of the date of this report; as no new merger shares will be issued, there will be no change in treasury shares after the merger. f. Transfer of employment relationships: the merging company will, in principle, succeed to the employment and related legal relationships of all employees of the company to be merged while maintaining existing employment conditions; details to be agreed between the two companies. g. Damages to class shareholders: Not applicable. h. Creditor protection procedures: under Article 527-5 of the Commercial Act, a creditor objection period of at least one month will be announced within two weeks of the shareholders' meeting date (or the replacing board resolution date), and known creditors will be separately notified. i. Other merger conditions: any matters not specified in the merger agreement will be determined by agreement between the representative directors of the Company and the target companies.

(4) Investment risk factors a. Risk factors that may hinder completion of the merger 1) Conditions for loss of effect under the merger agreement (Article 12): the agreement takes effect upon execution but may be immediately terminated before or on the merger date if: (1) both parties agree in writing to terminate; (2) either party fails to satisfy the conditions precedent under Article 11 by the merger date, at the other party's election; (3) either party fails to obtain required government approvals, or such approvals carry conditions reasonably expected to cause material adverse change or that are impossible or extremely difficult to satisfy, at either party's election; (4) either party breaches the agreement and fails to cure within 10 days of a cure request, at the other party's election (the breaching party cannot invoke this ground); (5) if shareholders holding 20% or more of SK Gas Co., Ltd.'s total issued shares notify opposition to the small-scale merger within two weeks of the announcement or notice date, at SK Gas Co., Ltd.'s election. Effects of termination: materials/information must be returned or destroyed within 14 days; termination does not affect either party's claims for damages or other remedies arising from breach; certain articles (12.2, 15, 16) survive termination. 2) Board resolution requirement: as SK Gas Co., Ltd.'s merger is a small-scale merger, the merger agreement loses effect if the board meeting (replacing the shareholders' meeting) fails to obtain attendance of a majority of directors and approval of two-thirds of attending directors. 3) Dissenting shareholders' notice: as this is a small-scale merger, under Article 527-3, Paragraph 4 of the Commercial Act, if shareholders holding 20% or more of the surviving company's total issued shares notify in writing their opposition within two weeks of the small-scale merger announcement date, the small-scale merger cannot proceed. b. Listing of new merger shares and delisting risk: Not applicable, as this is a merger without capital increase and not a backdoor listing. c. Risk factors to consider when investing in related securities if the merger proceeds: Not applicable. d. Option contracts related to the merger: Not applicable.

(5) Appraisal rights: as this merger is a small-scale merger under Article 527-3 of the Commercial Act, appraisal rights for dissenting shareholders are not recognized, and merger approval is replaced by board approval.

(6) Relationship between the merging companies a. Relationship: 1) As of the report date, SK Gas Co., Ltd. owns 70.0% of SK Advanced Co., Ltd.'s issued shares, with the remaining 30.0% owned by SK Gas Co., Ltd.'s wholly owned subsidiary SK Gas International Pte. Ltd. 2) Overlapping officers: Son Cheol-seung (SK Gas Co., Ltd. - Head of Finance Division, unregistered; SK Advanced Co., Ltd. - Other non-standing director, registered); Hong Jong-beom (SK Gas Co., Ltd. - Head of Optimization Office, unregistered; SK Advanced Co., Ltd. - Other non-standing director, registered); Choi Yi-ruk (SK Gas Co., Ltd. - Head of Finance Office, unregistered; SK Advanced Co., Ltd. - Auditor, registered). 3) As SK Advanced Co., Ltd. is a consolidated subsidiary of SK Gas Co., Ltd., SK Gas's largest shareholder and related parties are related parties of SK Advanced. 4) The two companies are in a complementary relationship in propane supply and propylene production business activities. b. Transactions between the merging companies: 1) Investment - on June 14, 2016, SK Gas Co., Ltd. sold a 25% stake (850,165 shares) in SK Advanced Co., Ltd. to PIC (Petrochemical Industries Company K.S.C), and on June 15, 2016 purchased a 5% stake (170,033 shares) from AGIC (Advanced Global Investment Company), changing its stake from 65% (2,210,429 shares) to 45% (1,530,297 shares). On February 10, 2026, SK Gas Co., Ltd. purchased a 25% stake (850,165 shares) from PIC, changing its stake from 45% (1,530,297 shares) to 70% (2,380,462 shares). 2) Loans: Not applicable. 3) Debt guarantees - SK Gas Co., Ltd. has provided fund-reimbursement commitments to third parties in connection with SK Advanced Co., Ltd.'s debt (as of August 25, 2026; KRW thousand): guarantee to Reverse Jeil-cha Co., Ltd., period from 2025-11-28, total guaranteed amount 70,000,000 (Notes 1,2); guarantee to KIS-SF 49th Co., Ltd., period from 2025-11-28, total guaranteed amount 100,000,000 (Note 1); total 170,000,000. (Note 1) These are fund-reimbursement commitments for asset-backed securities issued by SPCs secured by the dissolving company's loans and unregistered unsecured bonds, running until final repayment of principal and interest; amounts exclude interest. (Note 2) As of end-Q2 2026, the Company has established a maximum-amount mortgage of KRW 84,000 million on land and buildings it owns in consideration for these commitments. 4) Collateral provided: Not applicable. 5) Sales and purchase transactions (KRW thousand): 2024 - sales 567,058,504; other income and asset disposals 512,628; purchases -; other expenses and capital expenditures 291,758. 2025 - sales 515,905,372; other income and asset disposals 3,220,001; purchases -; other expenses and capital expenditures 611,916. (Based on 2024 and 2025 year-end.) 6) Trade receivables/payables, accrued items (KRW thousand): 2024 - trade receivables 157,392,391; other receivables 102,076; trade payables -; other payables 244,025. 2025 - trade receivables 166,031,590; other receivables 578,282; trade payables -; other payables 5,730,618. c. Transactions with the largest shareholder: credit extension - Not applicable; asset acquisition/disposal - Not applicable; business transactions - Not applicable.

(7) Other matters necessary for investor protection a. Past merger history: Not applicable. b. Largest shareholder's ownership status: as this merger proceeds without issuing new shares, there is no change in the surviving company's governance structure before or after the merger. c. Change in capital after the merger: as this is a merger without capital increase, there is no change in SK Gas Co., Ltd.'s total issued shares or capital after the merger. d. Officer composition and management policy: notwithstanding Article 527-4, Paragraph 1 of the Commercial Act, under the agreement between the companies, SK Gas Co., Ltd.'s directors will serve out their terms regardless of this merger unless a cause for termination of office arises; SK Advanced Co., Ltd.'s directors and auditor will lose their status as registered officers as of the merger registration date. e. Post-merger business plan: the Company aims to integrate business capabilities through this merger to improve management efficiency, expecting this to maximize cross-business synergy and enhance corporate value. f. Special committee operation: to secure objectivity and fairness in decision-making, the Company established a special committee composed entirely of independent directors, and received multi-faceted advice from external business, legal, financial and accounting experts. The special committee's final judgment was that proceeding with the merger is reasonable.

I. Special committee: (1) Composition - 4 independent directors (Chairman Jeong Yeong-chae, directors Park Ju-gyeong, Son Yang-hoon and Song Ji-yeon), all of whom attended all four meetings; composed solely of independent directors with no interest relationship with management or the controlling shareholder; members have expertise in capital markets, industry structure, management process, finance and law. (2) Authority - an independent pre-review and deliberation body granted authority to request materials, direct internal review, and request and verify opinions from external experts. (3) Established by board resolution on July 15, 2026, with the board secretariat as the dedicated communication channel; began operating with its first meeting the same day. (4) Activities - held four meetings reviewing the legitimacy of the transaction's purpose, fairness of terms, adequacy of procedure and potential shareholder conflicts of interest per Ministry of Justice guidelines, concluding the merger is reasonable and adopting a final review report for the board: 1st meeting (July 15, 2026) established review principles and the committee's operating plan; 2nd meeting (July 24, 2026) verified medium- to long-term economics from a propane value-chain perspective and the financial/operational benefits of the merger; 3rd meeting (August 11, 2026) reviewed integrated value-chain business value, legal/financial/business risks and responses, and fairness/procedural adequacy; 4th meeting (August 20, 2026) adopted the final Special Committee Review Report and resolved to report it to the board.

II. External experts: (1) Legal review by Shin & Kim LLC; accounting/financial review by Samil PwC, selected for continuity with existing analysis and expertise in corporate restructuring and capital markets law; both acted as independent third parties. (2) Shin & Kim LLC reviewed the merger's legal validity, related regulations, the legal suitability of the no-capital-increase structure, absence of shareholder conflicts of interest, and procedural legitimacy from a director's duty-of-care perspective. (3) Samil PwC performed a business valuation from an integrated value-chain perspective, a conservative corporate valuation, and verified the economic benefits and medium- to long-term cash-flow improvement from the merger versus standalone operation.

III. Protection of general shareholders' interests: (1) As this is a no-capital-increase absorption-merger of a wholly owned subsidiary, the merger ratio of 1:0.0000000 was set without a separate merger-value appraisal, and external appraisal is exempted; there is no structural issue of a merger ratio favoring any particular shareholder or unfair benefit to the controlling shareholder. (2) Procedural legitimacy was secured through the independent special committee and external experts' verification, and the Company will faithfully comply with the statutory small-scale merger procedure. (3) The Company will provide information on the merger through disclosures and communicate fully with investors regarding the merger's purpose and effects.

2. Matters concerning the merger counterparty (1) Company overview: Company name SK Advanced Co., Ltd.; Representative Kim Han-jo; Business registration number 610-86-30246; Head office 299 Yongyeon-ro, Nam-gu, Ulsan (SK Advanced); Phone 02-6200-8707; Website http://www.skadvanced.co.kr; Industry manufacture of basic petrochemical chemicals; Fiscal year-end December; Date of incorporation September 12, 2014; Listing status unlisted; SME status not applicable. (2) Business description: SK Advanced Co., Ltd. was established via a corporate spin-off from SK Gas Co., Ltd. under the Commercial Act, producing and selling propylene (byproducts: hydrogen, steam, C5+) from propane feedstock. SK Gas Co., Ltd. owns 70.00% of its shares, with the remaining 30.00% owned by SK Gas International Pte. Ltd. (3) Financial matters a. Summary balance sheet, most recent 3 fiscal years (KRW million) - 12th FY (2025) / 11th FY (2024) / 10th FY (2023): Current assets: 299,505 / 279,651 / 169,028 - Cash and cash equivalents: 132,199 / 163,448 / 69,872 - Short-term financial assets: - / - / 14,677 - Trade and other receivables: 146,602 / 102,420 / 58,483 - Current income tax assets: 351 / 625 / 375 - Derivative financial assets: 93 / - / 2,347 - Inventories: 12,579 / 10,150 / 15,835 - Other current assets: 7,681 / 3,008 / 7,439 Non-current assets: 639,751 / 769,130 / 803,962 - Long-term financial instruments: 98 / 2 / 2 - Long-term trade and other receivables: 2,375 / 2,483 / 2,592 - Derivative financial assets: 579 / 1,147 / - - Investments in joint ventures: 41,204 / 68,109 / 77,264 - Property, plant and equipment: 591,828 / 679,430 / 703,807 - Intangible assets: 750 / 1,209 / 1,645 - Right-of-use assets: 332 / 495 / 187 - Long-term guarantee deposits: 129 / 129 / 123 - Other non-current assets: 1,009 / 979 / 807 - Defined benefit assets: 1,447 / 1,709 / 610 - Deferred income tax assets: - / 13,438 / 16,925 Total assets: 939,256 / 1,048,781 / 972,990 Current liabilities: 697,163 / 490,167 / 295,440 Non-current liabilities: 56,973 / 326,444 / 280,622 Total liabilities: 754,136 / 816,611 / 576,062 Capital: 34,007 / 34,007 / 34,007 Capital surplus: 353,695 / 353,695 / 353,695 Other components of equity: 199,198 / - / - Accumulated other comprehensive income: (23) / (23) / (20) Retained earnings: (401,757) / (155,509) / 9,246 Total equity: 185,120 / 232,170 / 396,928 Valuation method for subsidiary/associate/joint-venture investments: cost method (all years) b. Summary income statement, most recent 3 fiscal years (KRW million) - 12th FY (2025) / 11th FY (2024) / 10th FY (2023): Revenue: 610,098 / 688,078 / 599,093 Operating profit (loss): (140,047) / (116,133) / (82,525) Net income: (244,813) / (165,712) / (112,359) Other comprehensive income: (812) / 955 / (1,082) Total comprehensive income: (245,626) / (164,757) / (113,441) Basic and diluted EPS (KRW): (72,173) / (48,729) / (33,040) c. Financial statement restatements: Not applicable. d. SPAC financial regulations and costs: Not applicable. e. Dividends: no dividend history in the most recent 3 fiscal years. f. Equity securities issuance: none in the most recent 3 fiscal years. (4) Auditor's opinion: 2023, 2024 and 2025 - Hanyoung Accounting Corporation, unqualified each year. (5) Board: as of the report date, SK Advanced Co., Ltd.'s board comprises 1 standing (in-house) director, 2 other non-standing directors and 1 auditor (4 total). (6) Shareholders (shares, %): SK Gas Co., Ltd. 2,380,462 shares, 70.00%; SK Gas International Pte. Ltd. 1,020,198 shares, 30.00%. (7) Officers and employees a. Officer status (as of August 25, 2026): Kim Han-jo (M, born Jan. 1977) - CEO, standing in-house director, registered, B.A. Economics Seoul National University, formerly Head of Corporate Culture Office at SK Gas/SK Discovery, officer of the largest shareholder, tenure 0 years 1 month, term expires March 31, 2029. Hong Jong-beom (M, born May 1977) - Other non-standing director, registered, Columbia University MBA, currently Head of Optimization Office at SK Gas Co., Ltd., officer of the largest shareholder, tenure 1 year 3 months, term expires March 31, 2029. Son Cheol-seung (M, born Jul. 1971) - Other non-standing director, registered, University of Chicago MBA, currently Head of Finance Division at SK Gas Co., Ltd., officer of the largest shareholder, tenure 4 years 3 months, term expires March 31, 2029. Choi Yi-ruk (M, born Feb. 1974) - Auditor, registered, Korea University Trade, currently Head of Finance Office at SK Gas, officer of the largest shareholder, tenure 1 year 3 months, term expires March 31, 2028. Kim Gyu-woong (M, born Jul. 1970) - Office head, unregistered, standing, Yeungnam University Business Administration, formerly Accounting Group PL at SK Gas, not a related party, tenure 4 years 2 months. Other non-standing directors Mishal Al Subaie and Wael Al Jassim resigned February 10, 2026; Mamdouh Al-Amri and Abdulaziz Al-Ardhi resigned April 16, 2026; in-house director Kim Cheol-jin resigned and Kim Han-jo was newly appointed as in-house director on June 1, 2026. b. Employee status (as of June 30, 2026; KRW thousand): PDH business male - 83 regular + 2 fixed-term = 85 employees, average tenure 9.6 years, total annual salary 5,170,153, average salary per person 60,825. PDH business female - 7 regular + 0 fixed-term = 7 employees, average tenure 8.1 years, total annual salary 246,597, average salary per person 35,228. Total - 90 regular + 2 fixed-term = 92 employees, average tenure 9.5 years, total annual salary 5,416,749, average salary per person 58,878. c. Unregistered officer compensation (as of June 30, 2026; KRW thousand): 1 unregistered officer, total annual salary 94,554, average per person 94,554. (8) Affiliates: SK Gas Co., Ltd. and SK Advanced Co., Ltd. both fall within the SK business group under the Monopoly Regulation and Fair Trade Act, and the largest shareholder and related parties of either party are related parties of the other. (9) Other matters necessary for investor protection a. Material litigation: Not applicable. b. Other contingent liabilities: 1) Guarantees and borrowing arrangements as of end-Q2 2026 (limit / executed, end-Q2 2026; limit / executed, end-2025): Hana Bank comprehensive limit (Note 1) USD 7,500,000 / USD 6,487,188; USD 7,500,000 / USD 6,969,127. Hana Bank KRW general borrowing KRW 10,000 million / KRW 10,000 million; KRW 10,000 million / KRW 10,000 million. Woori Bank foreign-currency guarantee (Note 2) USD 15,300,000 / USD 15,300,000; USD 15,300,000 / USD 15,300,000. Shinhan Bank KRW loan limit KRW 10,000 million / KRW 10,000 million; same at end-2025. NongHyup Bank KRW loan limit KRW 20,000 million / KRW 20,000 million; same at end-2025. KB Kookmin Bank KRW loan limit KRW 10,000 million / KRW 10,000 million; same at end-2025. KDB working-capital loan KRW 72,000 million / KRW 72,000 million; same at end-2025. Bank of China trade-finance comprehensive limit USD 5,000,000 / nil; same at end-2025. (Note 1) Comprehensive limit covering foreign-currency working-capital loans, trade bill loans, import L/C issuance and other foreign-currency guarantees. (Note 2) Woori Bank issued a guarantee of USD 15,300,000, equal to 102% of the 3rd foreign-currency private placement bond issuance amount. 2) Credit enhancement provided: Not applicable. (3) Fund-reimbursement commitment: as of end-Q2 2026, in connection with related party Ulsan PP Co., Ltd.'s facility loan of KRW 209,196 million, SK Advanced Co., Ltd. entered into a commitment with KDB and other lenders to contribute or lend up to KRW 10,000 million if there is a shortfall in principal/interest repayment. 4) Future receivables securitization and debt ratio: Not applicable. c. Sanctions: Not applicable.

(condensed translation)