Feb. 24, 2026: Consolidated Financial Results for the Nine Months Ended December 31, 2025 (Completion of the Interim Review by the Audit Firm)

February 24, 2026 Company name: NIPPON STEELCORPORATION

Representative: Tadashi Imai

Representative Director, President and COO (Code number: 5401, TSE Prime, NSE, FSE, and SSE) Contact: Public Relations Department,

Corporate Communications Division (Telephone: +81-3-6867-2135, 2141, and 2146)

NIPPON STEEL CORPORATION ("the Company") hereby announces that the interim review by the audit firm for the Company's quarterly consolidated financial statements in the "Consolidated Financial Results for the Nine Months Ended December 31, 2025 ＜under IFRS＞" disclosed on February 5, 2026, has been completed. There is no change from the quarterly consolidated financial statements disclosed on February 5, 2026.

Company name: NIPPON STEEL CORPORATION

February 24, 2026

Stock listing: Tokyo Stock Exchange / Nagoya Stock Exchange / Fukuoka Stock Exchange

/ Sapporo Securities Exchange

Code number: 5401

URL: https://www.nipponsteel.com/en/index.html

Representative: Tadashi Imai, Representative Director, President and COO

Contact: Shinnosuke Arita, General Manager, Head of Corporate Communications Div.

Telephone: +81-3-6867-2135, 2141, 2146

Scheduled date to commence dividend payments: －

Preparation of supplemental explanatory materials: Yes

Holding of financial results meeting: Yes (for investment analysts)

(All amounts have been truncated to the nearest millions of Japanese yen.)

1. Consolidated financial results for the nine months ended December 31, 2025 (from April 1, 2025 to December 31, 2025)
   1. Consolidated operating results (cumulative)

      (Percentage figures are changes from the same period of the previous fiscal year.)

      	Revenue		Business profit (*1)		Operating	profit	Profit before income taxes		Profit
      Nine months ended	Millions of yen	%	Millions of yen	%	Millions of yen	%	Millions of yen	%	Millions of yen	%
      December 31, 2025	7,256,323	10.7	356,142	(37.1)	107,051	(81.1)	56,110	(89.8)	(20,811)	-
      December 31, 2024	6,552,498	(1.3)	566,125	(18.2)	566,125	(8.5)	548,013	(9.9)	386,394	(17.6)

      	Profit attributable to owners of the parent		Total comprehensive income		Basic earnings per share (*2)	Diluted earnings per share (*2)
      Nine months ended	Millions of yen	%	Millions of yen	%	Yen	Yen
      December 31, 2025	(45,002)	-	142,334	(62.3)	(8.61)	(8.61)
      December 31, 2024	362,077	(17.9)	377,615	(46.9)	73.60	69.30

      (*1)Business Profit on Consolidated Statements of Profit or Loss indicates the results of sustainable business activities, and is an important measure to compare and evaluate the Company's consolidated performance continuously. It is defined as being deducted Cost of sales, Selling, general and administrative expenses and Other operating expenses from Revenue, and added Share of profit in investments accounted for using the equity method and Other operating income. Other operating income and expenses are composed mainly of Dividend income, Foreign exchange gains or losses, and Losses on disposal of fixed assets.

      (*2)The Company implemented a stock split at a ratio of five (5) shares for every one share effective October 1, 2025. Accordingly, basic earnings per share and diluted earnings per share are calculated as if the stock split had occurred at the beginning of the fiscal year ended March 31, 2025.

   2. Consolidated Financial Position

   	Total assets	Total equity	Total equity attributable to owners of the parent	Ratio of total equity attributable to owners of the parent to total assets
   As of	Millions of yen	Millions of yen	Millions of yen	%
   December 31, 2025	14,443,085	5,851,165	5,321,842	36.8
   March 31, 2025	10,942,458	5,903,380	5,383,311	49.2

2. Dividends

   	Dividends per share
   	First quarter-end	Second quarter-end	Third quarter-end	Fiscal year-end	Total
   	Yen	Yen	Yen	Yen	Yen
   Fiscal year ended March 31, 2025	-	80.00	-	80.00	160.00
   Fiscal year ending March 31, 2026	-	60.00	-
   Fiscal year ending March 31, 2026(Forecasts)				12.00	-

   Note: Revisions to the forecast of cash dividends most recently announced: No

   *The Company implemented a stock split at a ratio of five (5) shares for every one share effective October 1, 2025.

   The dividend for the second quarter of the fiscal year ending March 31, 2026, with a record date of September 30, 2025, was applied to the Company's common shares before the stock split. Therefore, the dividend is stated as the amount before the stock split. The year-end dividend for the fiscal year ending March 31, 2026, with a record date of March 31, 2026, will apply to the Company's common shares after the stock

   split. Therefore, the dividend is stated as the amount after the stock split. Due to the impact of the stock split, the second quarter dividend and the year-end dividend cannot be simply added together, so the total annual dividend is stated as "-". Note that if the stock split is not considered, the year-end dividend for the fiscal year ending March 31, 2026, would be 60 yen per share, and the total annual dividend would be 120 yen per share.

3. Consolidated Financial Forecasts for Fiscal year ending March 31, 2026

(Percentage figures are changes from the same period of the previous fiscal year.)

Note: Revisions to the consolidated financial forecasts most recently announced: No

There are no changes to the forecasts of financial results from the recent revision made by the Company in the unreviewed Consolidated Financial Results for the Nine Months Ended December 31, 2025 disclosed on February 5, 2026.

*The Company implemented a stock split at a ratio of five (5) shares for every one share effective October 1, 2025. Accordingly, Basic earnings

per share is calculated as if the stock split had occurred at the beginning of the fiscal year ended March 31, 2026.

• Notes

  1. Significant changes in the scope of consolidation during the period: Yes The changes in the scope of consolidation during the period are as follows; Number of newly consolidated: 107

     Company name: United States Steel Corporation and its subsidiaries, total 87 companies Number of excluded from consolidation: 26

  2. Changes in accounting policies and changes in accounting estimates

     1. Changes in accounting policies required by IFRS: None

     2. Changes in accounting policies other than those in (a) above: None

     3. Changes in accounting estimates: None

  3. Number of shares outstanding (common shares)

     1. Number of shares outstanding at the end of the period (including treasury stock) As of December 31, 2025 5,373,633,760 shares

        As of March 31, 2025 5,373,633,760 shares

     2. Number of treasury stock at the end of the period

        As of December 31, 2025 147,330,767 shares

        As of March 31, 2025 147,691,101 shares

     3. Weighted average number of shares outstanding

        Nine months ended December 31, 2025 5,226,230,350 shares

        Nine months ended December 31, 2024 4,919,296,612 shares

        *The Company implemented a stock split at a ratio of five (5) shares for every one share effective October 1, 2025. Accordingly, the number of shares outstanding at the end of the period, the number of treasury stock at the end of the period, and the weighted average number of shares outstanding are calculated as if the stock split had occurred at the beginning of the fiscal year ended March 31, 2025.

• Review of the attached consolidated quarterly financial statements by certified public accountants or an audit firm: Yes (voluntary)

• Explanation of the appropriate use of performance forecasts and other related items (Explanation of the appropriate use of performance forecasts)

The forward-looking statements included in this consolidated financial results are based on the assumptions, forecasts, and plans of the Company as of the date on which this document is made public. The Company's actual results may differ substantially from such statements due to various risks and uncertainties.

(Financial forecasts after the stock split)

The Company decided at the Board of Directors meeting held on August 1, 2025 to conduct a stock split. The stock split at a ratio of five (5) shares for every one share was effective on October 1, 2025. Accordingly, basic earnings per share in the consolidated financial forecasts for fiscal year ending March 31, 2026 are calculated in consideration of the stock split.

NIPPON STEEL CORPORATION (5401)

Nine months ended December 31, 2025

1. Summary of Operating Results 2

2. Quarterly Condensed Consolidated Financial Statements and Major Notes 3

   1. Quarterly Condensed Consolidated Statements of Financial Position 3

   2. Quarterly Condensed Consolidated Statements of Profit or Loss and

      Quarterly Condensed Consolidated Statements of Comprehensive Income 5

   3. Quarterly Condensed Consolidated Statements of Changes in Equity 6

   4. Notes to the Quarterly Condensed Consolidated Financial Statements 8

(Going Concern Assumption) 8

(Cash-Flows) 8

(Segment Information) 8

(Business Combinations) 9

Independent Auditor's Report on Review of Quarterly Condensed Consolidated Financial Statements 11

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NIPPON STEEL CORPORATION (5401)

Nine months ended December 31, 2025

1. Summary of Operating Results

For the Summary of Operating Results for the nine months ended December 31, 2025, please refer to the supplementary explanation materials "Results for the nine months ended December 31, 2025" disclosed on TDnet and "IR Briefing: Presentation" posted on our company's website on February 5.

For the merger between U.S. subsidiary and United States Steel Corporation ("U. S. Steel"), which was completed on June 18, 2025, please refer to "Nippon Steel Corporation and U. S. Steel Finalize Historic Partnership" posted on the company's website.

Link to IR Briefing: https://www.nipponsteel.com/en/ir/library/settlement.html

(This material is available on the company's website under "IR archive"- "Financial results.")

Link to U. S. Steel Merger Document: https://www.nipponsteel.com/en/ir/news/ (This material is available on the company's website under "IR Topics")

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