Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Table of Contents

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Company Information / Capital Breakdown

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Consolidated Table - Highlights

¹ Adjusted EBITDA is calculated from net income (loss), plus depreciation and amortization, taxes on profit, net financial result, investment participation result, other operating income/expenses result and includes the proportional share of 37.27% of the EBITDA of the joint subsidiary MRS Logística.

² Adjusted EBITDA Margin is calculated from Adjusted EBITDA divided by Management Net Revenue.

³ Adjusted Net Debt and Adjusted Cash/Availability consider 37.27% of MRS, in addition to not considering Forfaiting and Drawn Risk operations.

Consolidated Results

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Adjusted EBITDA

*The Company discloses its Adjusted EBITDA excluding participation in investments and other operating income (expenses) because it understands that they should not be considered in the calculation of recurring operating cash generation.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Adjusted EBITDA (R$ MM) and Adjusted EBITDA Margin¹ (%)

¹ The Adjusted EBITDA Margin is calculated from the division between Adjusted EBITDA and Adjusted Net Revenue, which considers the interests of 100% in the consolidation of CSN Mineração and 37.27% in MRS.

Adjusted Cash Flow

Adjusted Cash Flow in 3Q23 was positive by R$ 1,022 million, as a result of the combination of strong operating performance and efficient working capital management, yet with another reduction in inventory observed during the period.

Adjusted cash flow¹ in 3Q23 (R$ MM)

¹ The concept of Adjusted cash flow is calculated from Adjusted EBITDA, subtracting Ebitda from Joint Subsidiaries, CAPEX, IR, Financial Result and changes in Assets and Liabilities², excluding the effect of the Glencore advance.

² The Adjusted Working Capital is composed of the variation of the Net Working Capital, plus the variation of accounts of long-term assets and liabilities and disregarding the net variation of IR and CS.

Indebtedness

On 09/30/2023, consolidated net debt reached R$ 29,939 million, with the leverage indicator measured by the LTM Net Debt/EBITDA ratio reaching 2.63x, which represents a reduction of 150 basis points compared to the previous quarter. With the peak leverage of the year behind us, the Company remains firm in its path of reducing its debt ratio and is on track to deliver an increasingly solid capital structure, even more so when considering the normalization of the steel operation and the growth potential of the cement segment, after synergy captures are complete. In addition, CSN maintained its policy of carrying a high cash position, which reached R$ 16 billion in this quarter.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Indebtedness (R$ Billion) and Net Debt / Adjusted EBITDA (x)		Net Debt Build-Up (R$ Billions)

¹ Net Debt / EBITDA: For debt calculation considers the final dollar of each period and for net debt and EBITDA the average dollar of the period.

The Company remains very active in its objective of extending the amortization period, focusing on long-term operations and the local capital market. Among the main transactions in 3Q23, CSN's 14^th issuance of simple debentures stands out, in the total amount of R$ 700 million, with the objective of investing in railway infrastructure, in the logistics and transportation segment.

Amortization Schedule (R$ Bi)

¹ IFRS: does not consider participation in MRS (37.27%).

² Management Gross / Net Debt considers participation in MRS (37.27%), without accrued interest.

³ Average Term after completion of the Liability Management Plan.

Foreign Exchange Exposure

The accumulated net foreign exchange exposure in the consolidated balance sheet up to 3Q23 was US$ 456 million, as shown in the table below, in line with the company's policy of minimizing the impacts of exchange rate volatility on the result. The Hedge Accounting adopted by CSN correlates the projected flow of dollar exports in dollars with the future maturities of the debt in the same currency. As a result, the exchange variation of the dollar debt is temporarily recorded in the shareholders' equity and is taken to the result when the dollar revenues from such exports occur.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Investments

A total of R$ 1,191 million were invested in 3Q23, 20.2% higher than the amount invested in 2Q23, with emphasis on repairs to coke batteries at UPV and general repairs to steel operations. In the mining segment, we highlight the current investments to maintain operational capacity and progress in expansion projects (mainly related to P15, recovery of tailings from dams and expansion of the Itaguaí port), accompanied by current investments in cement operations.

Net Working Capital

Net Working Capital applied to the business totaled R$ 1,922 million in 3Q23, a reduction of 36.1% compared to 2Q23, due to (i) the Company's lower inventory volume, in line with the increase in sales recorded in the period, and (ii) an increase in the number of CSN suppliers.

The calculation of the Net Working Capital applied to the business disregards the advance on the sales of ore, as shown in the following table:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

¹ Other CCL Assets: Considers employee advances and other accounts receivable.

² Other CCL Liabilities: Considers other accounts payable, dividends payable, installment taxes and other provisions.

³ Inventories: Does not consider the effect of the provision for inventory/inventory losses. For the calculation of the SME, the balances of warehouse stocks are not considered.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Results by Business Segments

Net Revenue by Segment – 3Q23 (R$ million-before eliminations)

Adjusted EBITDA by Segment – 3Q23 (R$ million - before eliminations)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Results of the Steel Industry

According to the World Steel Association (WSA), global crude steel production totaled 460.4 million tons (Mt) in the third quarter of 2023, which represents a decrease of 4.5% compared to the previous quarter as a consequence of the seasonality of the period, but an increase of 1.9% compared to the same period in 2022, reflecting the higher level of activity in the Chinese market. The European Union reduced its production by 9.9% compared to the previous quarter and 6.5% compared to the same period last year, impacted by the environment of high interest rates, inflation and still high energy costs. In turn, China produced 56.3% of the global volume (259.3 Mt) in 3Q23, which corresponds to a quarterly reduction of 5.3 p.p., but an increase of 2.8 p.p. compared to the same period of the previous year. The expectations for 2023 remain positive as Chinese government incentives indicate a prospect of a 1.8% increase in global steel production, after a 3.3% contraction in 2022. Brazil, on the other hand, produced 8.0 Mt in 3Q23, which corresponds to a decrease of 2.4% in relation to the previous quarter and 3.6% when compared to the same period of the previous year, mainly impacted by the increase in imports. The outlook for local market activity in 2023 is less encouraging, even after the normalization of production by relevant players, but with intense competition with imported material and with demand still responding slowly to the cycle of cuts in the Selic rate and government stimulus through programs such as PAC, Minha Casa, Minha Vida, Plano Safra and etc.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Steel Production (thousand tons)

In the case of CSN, Slab Production in 3Q23 totaled 922 thousand tons, a performance 25.9% higher than in the previous quarter, which reflects the normalization of the operation after a series of bottlenecks faced in the first semester. In turn, the production of flat rolled products, our main market, reached 835 Kton, which represents an increase of 7.8% compared to 2Q23, reflecting the resumption of the production process and bringing the volume produced to numbers closer to previous periods.

Sales Volume (Kton) – Steel

Total sales reached 1,018 thousand tons in the third quarter of 2023, a volume 3.1% lower than in 2Q23. When analyzing the behavior in different markets, it can be seen that the domestic market showed growth even with all the pressure faced with imported products, with emphasis on the hot rolled products performance. Domestic sales totaled 747 thousand tons of steel products in 3Q23, which represents an increase of 1.1% compared to 2Q23 and reinforces the normalization of the operation and the Company's resilience in managing to maintain an assertive commercial strategy even with all the pressure seen in the period. In the foreign market, sales totaled 271 thousand tons in 3Q23 and were 13.0% lower than in 2Q23, as a result of seasonality and weaker dynamics in the European market. During the quarter, 5,000 tons were exported directly, and 267,000 tons were sold by subsidiaries abroad, of which, 67,000 tons were sold by LLC, 132,000 tons by SWT and 68,000 tons by Lusosider.

Regarding total Sales Volume in 3Q23, the main highlight was the flat steel segment for construction, with a 24.1% increase compared to the previous quarter. On the other hand, Automotive (-11.9%) and Home Appliances (-4.2%) appear among the main negative highlights after a stronger start to the year. In the year-on-year comparison, there was a significant recovery in Home Appliances and flat steel for construction, but with decreases in the other segments.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Slab Cost with deprec. (R$/t)		3Q23 Production Cost

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Mining Result

In the mining sector, the quarter was marked by high demand for iron ore in China and an improvement in price levels, with the appreciation of Platts that closed 3Q23 US$ 3.06 above the average observed in the previous quarter. Steel production in China remains at high levels, leading to increases in capacity utilization at Chinese steel mills and low levels of ore inventories at both Chinese mills and ports. This situation ended up weighing favorably on the price of ore and has been driven by the Chinese government's stimulus packages, in an attempt to inject liquidity into the economy and ensure low financing costs for the consumer, manufacturing, infrastructure and real estate segments. Such moves have boosted demand for iron ore, including for lower-quality products as margins at Chinese steel mills remain quite tight. In this scenario, the iron ore price closed 3Q23 with an average of US$ 114.04/dmt (Platts, Fe62%, N. China), 2.8% higher than in 2Q23 (US$ 110.98/dmt) and 10.4% higher than in 3Q22 (US$ 103.31 /dmt). 

Regarding Sea Freight, the BCI-C3 Route (Tubarão-Qingdao) presented an average of US$ 20.3/wmt in 3Q23, which represents a reduction of 3.6% compared to the freight cost of the previous quarter, as a reflection of the increase in spot supply in the Atlantic Ocean. In addition, the rainy season in Africa and the large amount of cargo negotiated within contracts supported this scenario, helping to offset the increase in fuel prices in the period.

Total Production – Mining (Thousand tons)		Sales Volume – Mining (Thousand tons)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Cement Result

According to the National Union of the Cement Industry (SNIC), cement sales in Brazil from January to September 2023 had a slight decrease of 2.0% when compared to the same period of the previous year. This scenario reflects a normalization of the market after the boom experienced during the pandemic, plus the effects of a still high interest rate, the maturation of the new public policies of a government in its first year in office and a volume of rainfall above the historical average, especially in some regions such as the South of the country. On the other hand, even considering all these effects, the market remains quite resilient and already shows some signs of recovery. For example, cement sales in Brazil grew 8.3% in 3Q23 compared to the previous quarter and the consumer confidence index reached the highest level since 2014. In addition, job recovery scenario and GDP, in addition to the cooling of inflation and the beginning of the downward trajectory of interest rates are other indications that should boost sales in the coming months. Finally, the announcement of the new modality of the Growth Acceleration Program (PAC) and the reformulation of Minha Casa, Minha Vida are new evidence that should provide even more support for a new growth cycle in the sector.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

In terms of commercial performance, CSN's sales in 3Q23 totaled 3,263 Kton, which represents a small decrease of 2.1% compared to the previous quarter, but 4% above the same period of the previous year.

Sales Volume - Cement (thousand tons)

* LafargeHolcim's operations were integrated in September 2022.

Energy Result

In 3Q23, energy prices remained at a level still below the average of recent years, due to the high level of water that has been recorded in the reservoirs. As a result, the volume of energy traded in the quarter generated Net Revenue of R$ 122 million, which represents a reduction of 23.5% compared to the previous quarter. Adjusted EBITDA also decreased in the period, reaching R$ 25 million and generating an Adjusted EBITDA Margin of 20.3%, which represents a reduction of 23.1 p.p. compared to the previous quarter, when the recognition of tax credits favored profitability.

Logistics Result

Railway Logistics: In 3Q23, Net Revenue reached RR$ 730 million, with an Adjusted EBITDA of R$ 406 million and Adjusted EBITDA Margin of 55.7%. Compared to 2Q23, revenue increased 9.2% due to the seasonality of the period and a higher volume of goods transported. In the same line of comparison, Adjusted EBITDA was 12.2% higher.

Port Logistics: In 3Q23, 292 thousand tons of steel products were shipped by Sepetiba Tecon, in addition to 14 thousand containers, 4 thousand tons of general cargo and 239 thousand tons of bulk. Compared to the previous quarter, the Company

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

significantly increased its shipments, with the increase in the volume of steel products and in the volume of bulk. As a result, Net Revenue from the port segment was 37.3% higher than in the previous quarter, reaching R$ 75 million in 3Q23, with a positive impact on Adjusted EBITDA for the period, which was R$ 19 million in the quarter and Adjusted EBITDA Margin of 25.2%, or 20.2 p.p. higher than in 2Q23.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

ESG – Environmental, Social & Governance

ESG PERFORMANCE – CSN GROUP

Since the beginning of 2023, CSN has adopted a new format for disclosing its ESG actions and performance, providing its performance in ESG indicators on an individual basis. The new model allows stakeholders to have access to the main results and indicators on a quarterly basis and to monitor them effectively and even more quickly. Access can be made through the results center on CSN's IR website: https://ri.csn.com.br/informacoes-financeiras/central-de-resultados/

The information included in this release was selected based on relevance and materiality to the company. Quantitative indicators are presented compared to the period that best represents the metric for monitoring them. Thus, some are compared to the same quarter of the previous year, and others will be compared to the average of the previous period, ensuring a comparison based on seasonality and periodicity. Additionally, it is important to highlight that the ESG Performance Report also incorporates the performance indicators of the new assets of CSN Cimentos, acquired in 2022, so that some absolute indicators will change significantly when compared to the previous period.

More detailed historical data on CSN's performance and initiatives can be found in the 2022 Integrated Report, released in April 2023 (https://esg.csn.com.br/nossa-empresa/relatorio-integrado-gri ). ESG indicator assurance occurs annually for the Integrated Report's closing, so the information contained in quarterly releases is subject to adjustments resulting from this process.

It is also possible to track CSN's ESG performance in an agile and transparent manner on our website through the following electronic address: https://esg.csn.com.br .

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Capital Markets

In the third quarter of 2023, CSN's shares were practically stable (+0.1%), while the Ibovespa index fell 1.3%. The average daily volume (CSNA3) traded on B3, in turn, was R$ 100.8 million in 3Q23. On the New York Stock Exchange (NYSE), the Company's American Depositary Receipts (ADRs) depreciated 7.7% in dollar terms, while the Dow Jones index decreased 2.6%. The average daily trading of ADRs (SIDs) on the NYSE in 3Q23 was US$ 5.9 million.

Earnings Conference Call:

3Q23 Earnings Presentation Webcast Investor Relations Team

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

INCOME STATEMENT

CONSOLIDATED – Corporate Law – In Thousands of Reais

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

BALANCE SHEET

CONSOLIDATED – Corporate Law – In Thousands of Reais

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

CASH FLOW STATEMENT

CONSOLIDATED – Corporate Law – In Thousands of Reais

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

EXPLANATORY NOTES TO THE FINANCIAL STATEMENTS
(In thousands of reais, unless otherwise noted)

Companhia Siderúrgica Nacional (“CSN”, also referred to as “Company” or “Parent company”), is a publicly held company incorporated on April 9, 1941, under the laws of the Federative Republic of Brazil (Companhia Siderúrgica Nacional, its subsidiaries, joint ventures, joint operations and associates are collectively referred to herein as the "Group”). The Company’s registered office is located in São Paulo, SP, Brazil.

CSN is listed on the São Paulo Stock Exchange (B3 S.A. - Brasil, Bolsa, Balcão) and on the New York Stock Exchange (“NYSE”), reporting its information to the Brazilian Securities and Exchange Commission (“CVM”) and to the U.S. Securities and Exchange Commission (“SEC”).

The Group's main operating activities are divided into five 5 segments as follows:

The Company’s main industrial facility is the Presidente Vargas Steelworks (“UPV”), located in the city of Volta Redonda, State of Rio de Janeiro. This segment consolidates all operations related to the production, distribution and sale of flat steel, long steel, metallic containers and galvanized steel. In addition to the facilities in Brazil, CSN has commercial operations in the United States and operations in Portugal and Germany in order to gain markets and provide excellent services to final consumers. Its steel is used in home appliances, civil construction, package and automobile industries.

The production of iron ore is developed in the cities of Congonhas, Belo Vale and Ouro Preto, State of Minas Gerais, by its subsidiary CSN Mineração S.A. (“CSN Mineração”). The Company’s mining activities also include tin exploration in the state of Rondônia by CSN's subsidiary Estanho de Rondônia S.A. (“ERSA”), to supply the needs of the UPV. The surplus of this raw material is sold to subsidiaries and third parties.

Iron ore is sold basically in the international market, especially in Europe and Asia. The prices charged in these markets are historically cyclical and subject to significant fluctuations over short periods of time, driven by several factors related to global demand, strategies adopted by the major steel producers, and the foreign exchange rate. All these factors are beyond the Company’s control. The ore is transported by rail to the Terminal de Carvão e Minérios from the Itaguaí Port (“TECAR”), a solid bulk terminal, one of the four terminals that comprise the Itaguai Port, located in the State of Rio de Janeiro and from TECAR to customers around the world. The imports of coal and coke are also carried out through this terminal by provision of services by CSN Mineração to CSN.

As a pioneer in the use of technologies that result in the possibility of stacking the tailings generated in the iron ore production process, CSN Mineração has its iron ore production, since January 2020, 100% independent of tailings dams. After significant investments in recent years to raise the level of reliability, disposal and dry stacking, CSN Mineração has advanced to a scenario in which 100% of our tailings goes through a dry filtering process and are stacked in piles, geotechnically controlled, in areas exclusively destined for stacking.

As a consequence of these measures, decommissioning of dams is the natural path for processing filtered tailings. All of our mining dams are positively certified and comply with the environmental legislation in force.

CSN entered the cement market driven by the synergy between this activity and its existing businesses. The cement production unit located next to the UPV facilities, in Volta Redonda/RJ, produces CP-III type cement using slag produced by UPV's own blast furnaces. There is also the exploration of limestone and dolomite at the Arcos/MG unit to meet the needs of the steel industry and the cement factory, as well as the production of clinker at the same unit.

On August 31, 2021, the subsidiary CSN Cimentos S.A. (“CSN Cimentos”) concluded the acquisition of control of Elizabeth Cimentos S.A. and Elizabeth Mineração Ltda., operating in the Northeast region, especially in Paraíba and Pernambuco. On May 1, 2022, Elizabeth Mineração was merged into CSN Cimentos.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

On September 9, 2021, CSN Cimentos entered into the Agreement for the Sale and Purchase of the Shares in LafargeHolcim (Brasil) S.A., for the acquisition of 100% of the shares issued by LafargeHolcim (Brasil) S.A. (“LafargeHolcim”). On September 6, 2022, the acquisition of all shares issued by LafargeHolcim S.A. was completed, with the corporate name of LafargeHolcim being changed to "CSN Cimentos Brasil S.A.", which became controlled by CSN Cimentos. The Company's main activities are: production, industry and general trade of cement, lime, mortar, minerals and metals in general and complementary products for civil construction, in natura with industrial plants, warehouses and branches across a large part of the national territory.

On August 31, 2023, the Extraordinary General Meeting approved the incorporation of CSN Cimentos by CSN Cimentos Brasil with the consequent transfer of all assets, properties (movable and immovable), rights and obligations, in accordance with the terms of the “Protocol and Justification of the Incorporation of CSN Cimentos S.A. by CSN Cimentos Brasil S.A.”. Thus, CSN Cimentos was extinguished, all its shares were canceled and, in replacement, its shareholders received shares in CSN Cimentos Brasil. All activities carried out by CSN Cimentos are now carried out by CSN Cimentos Brasil. The Valuation Report of CSN Cimentos' assets was prepared on June 30, 2023, serving as the basis for determining a capital increase in CSN Cimentos Brasil in the amount of R$2,383,276.

Railroads:

CSN has interests in three railroad companies: MRS Logística S.A. (“MRS”), which manages the former Southeast Railway System of Rede Ferroviária Federal S.A. (“RFFSA”), Transnordestina Logística S.A. (“TLSA”) and FTL - Ferrovia Transnordestina Logística S.A. (“FTL”), which holds the concession to operate the former Northeast Railway System of RFFSA, in the States of Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas - stretches from São Luís to Altos, Altos to Fortaleza, Fortaleza to Sousa, Sousa to Recife/Jorge Lins, Recife/Jorge Lins to Salgueiro, Jorge Lins to Propriá, Paula Cavalcante to Cabedelo, Itabaiana to Macau (Mesh I) and TLSA is responsible for the stretches from Eliseu Martins-Trindade, Trindade-Salgueiro, Salgueiro-Missão Velha and Missão Velha-Pecém (Mesh II), under construction.

Ports:

The Company operates in the State of Rio de Janeiro, by means of its subsidiary Sepetiba Tecon S.A., the Container Terminal (“TECON”) and by means of its subsidiary CSN Mineração, the TECAR, both located at the Itaguaí Port. Established in the harbor of Sepetiba, the mentioned port has a privileged highway, railroad, and maritime access.

TECON is responsible for the movement and storage of containers, vehicles, steel products, general cargo, among other products, and TECAR performs the operational activities of loading and unloading of solid bulk ships, storage and distribution (road and rail) of coal, coke, petroleum coke, clinker, zinc concentrate, sulfur, iron ore and other bulk, intended for the seaborne market, for our own operation and for different customers.

Since the energy supply is fundamental in CSN”s production process, the Company has electricity generation assets to mitigate costs, aiming at greater competitiveness.

On June 30, 2022, the Company's subsidiaries, CSN Cimentos and CSN Energia S.A. ("CSN Energia"), completed the acquisition of Santa Ana Energética S.A. (“Santa Ana”), as well as Topázio Energética S.A. ("Topázio") and, indirectly, Brasil Central Energia Ltda. ("BCE"), a subsidiary of Topázio, under the terms of the Share Purchase Agreement entered into on April 8, 2022 with Brookfield Americas Infrastructure (Brazil Power) Fundo de Investimento em Participações Multiestratégia, managed by Brookfield Brasil Asset Management Investimentos Ltda. On October 7, 2022, subsidiaries CSN Mineração and CSN Energia S.A. concluded the acquisition of 100% of the shares of Companhia Energética Chapecó – CEC, holder of the grant of Quebra-Queixo Hydroelectric Power Plant (“Chapecó”), as provided for in the Agreement for the Purchase and Sale of Shares and Other Covenants and in the Private Instrument of Assignment of Rights and Obligations entered into on July 1, 2022 and July 25, 2022, respectively.

In July 2022, The Company won the auction held by the State of Rio Grande do Sul, for the sale of 100% of the shares in its possession, 6,381,908 equivalent to 66.23% of the share capital, of Companhia Estadual de Energia Elétrica - CEEE-G, as part of the CEEE Group privatization program, in accordance with State Law 15.298/19.On October 21, 2022, the transaction was completed with payment by the company of the auction winning price. On December 22, 2022, the acquisition of Eletrobras' 32.74% interest in CEEE-G was concluded, and the Company currently holds 99% of the share capital of CEEE-G.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Management understands that the Company has adequate resources to continue its operations. Accordingly, the Company's interim financial information for the period ended September 30, 2023, have been prepared on a going concern basis.

The parent company and consolidated interim financial information (“interim financial information”) have been prepared and are being presented in accordance with the accounting practices adopted in Brazil issued by the Brazilian Accounting Pronouncements Committee (“CPC”), approved by the Brazilian Securities and Exchange Commission (“CVM”) and by the Brazilian Federal Accounting Council (“CFC”), and in accordance with the International Financial Reporting Standards (“IFRS”) issued by the International Accounting Standard Board (“IASB”) and disclose all the relevant information of the interim financial information, and only this information, which corresponds to that used by the Company's management in its activities. The consolidated interim financial information are identified as “Consolidated” and the parent company's individual interim financial information are identified as “Parent Company”.

The interim financial statements were prepared based on the historical cost and were adjusted to reflect: (i) the fair value measurement of certain financial assets and liabilities (including derivative instruments), as well as pension plan assets; and (ii) impairment losses. When IFRS and CPCs allows the option between cost or another measurement criterion, the cost of acquisition criterion was used.

The preparation of these interim financial statements requires Management to use certain accounting estimates, judgments and assumptions that affect the application of Accounting Polices and the amounts reported on the balance sheet date of assets, liabilities, income, and expenses may differ from actual future results. The assumptions used are based on history and other factors considered relevant and are reviewed by the Company’s management.

The interim financial information has been prepared and is being presented in accordance with CPC 21 (R1) - “Interim Financial Reporting” and IAS 34 - “Interim Financial Reporting”, consistently with the standards issued by the CVM. This interim financial information does not include all requirements of annual or full financial statements and, accordingly, should be read in conjunction with the Company’s financial statements for the year ended December 31, 2022.

Therefore, in this interim financial information the following notes are not repeated, either due to redundancy or to the materiality in relation to those already presented in the annual financial statements:

Note 10 - Basis of consolidation and investments

Note 12 - Intangible assets

Note 18 - Income tax and social contribution

Note 19 - Installment taxes

Note 20 - Tax, social security, labor, civil, environmental provisions and judicial deposits

Note 29 - Information by business segment

Note 30 - Employee benefits

Note 31 - Commitments

The consolidated financial statements were approved by Board of Directors on November 13, 2023.

The accounting records included in the interim financial statements of each of the Company’s subsidiaries are measured using the currency of the principal of the economic environment in which each subsidiary operates (“the functional currency”). The consolidated and parent company interim financial statements are presented in BRL (reais), which is the Company’s functional and reporting currency.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Foreign currency transactions are translated into the functional currency using the exchange rates prevailing on the transaction or valuation dates, in which the items are remeasured. The balances of the asset and liability accounts are converted using the exchange rate on the balance sheet date. As of September 30, 2023, US$1.00 was equivalent to BRL5.0076 (BRL5.2177 on December 31, 2022) and €1.00 was equivalent to BRL5.3000 (BRL5.5694 on December 31, 2022), according to the rates obtained from Central Bank of Brazil website.

Pursuant to Law 11,638/07, the presentation of the statement of added value is required for all publicly held companies. These statements were prepared in accordance with CPC 09 - Added Value Statement, approved by CVM Resolution 557/08. The IFRS does not require the presentation of this statement and for IFRS purposes is presented as additional information.

Our investments are basically in private and public securities with yields linked to the variation of Interbank Deposit Certificates (CDI) and repo operations backed by National Treasury Notes, respectively. The Company invests part of the funds through exclusive investment funds which have been consolidated in this interim financial information.

Our investments are in private securities in top-rated banks and are remunerated at pre-fixed rates.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

5.      TRADE RECEIVABLES

The composition of the gross balance of accounts receivable from third party consumers is shown as follows:

The changes in estimated credit losses are as follows:

The changes in estimated losses on inventories are as follows:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

Credits arise mainly from ICMS, PIS and COFINS on purchases of raw materials and fixed assets, in accordance with current legislation. These credits are naturally realized through offsetting with debts of the same nature or with other federal taxes, in the cases authorized by law. Based on analyses and projections made by Management, the Company does not expect risks of non-realization of these tax credits.

Other current and non-current assets are as follows:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

The information related to the activities of jointly controlled subsidiaries, joint operations, associates and other investments did not change in relation to what was disclosed in the Company's financial statements as of December 31, 2022. Therefore, Management decided not to repeat them in the accounting information interim of September 30, 2023.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

(*) Dormant companies.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

(1) On June 1, 2023, MAZET - Maschinenbau Zerspanungstechnik GmbH was acquired by the indirect subsidiary Stalhwerk Thüringen GmbH.

(2) On December 26, 2022, the Itaúba Consortium was formed, with Companhia Siderúrgica Nacional S.A., with a 63.4% stake, and CSN Cimentos Brasil S.A., with a 36.6% stake. Additionally, on January 17, 2023, the Passo Real Consortium was formed, with the consortium members Companhia Siderúrgica Nacional S.A., Elizabeth Cimentos S.A., CSN Mineração S.A. and Minérios Nacional S.A., with stakes of 46.97%, 28.18%, 23.29% and 1.56%, respectively.

(3) CEEE-G sold its ownership interest in affiliated companies Ventos Lagoa Energia S.A., Parques Eólicos Palmares S.A., Ventos do Litoral Energia S.A. and Ventos dos Índios Energia S.A.

The positions presented as of September 30, 2023 and the changes refer to the interest held by CSN in these companies:

(1) Refers mainly to the alienation by CEEE-G in the first quarter of its equity interest in affiliates Ventos Lagoa Energia S.A., Parques Eólicos Palmares S.A., Ventos do Litoral Energia S.A. and Ventos dos Índios Energia S.A., consequently, there was a write-off of these investments in the amount of (R$47,611), the effect of the operation was classified under the category of other operating expenses and revenues;

(2) The balance of R$359,024 refers to the Fair Value generated in the acquisition of the company CEEE-G, with the disposals mentioned in the item above, the Fair Value was written off in the amount of (R$39,314) referring to the capital gains of the companies sold, the effect of the write-off was classified under the equity method category;

(3) These are strategic investments in startups made by the subsidiary CSN Inova Ventures, which are valued using the cost method, in the following companies: Alinea Health Holdings Ltda. I.Systems Aut. Ind., 2D Materials, H2Pro Ltda, 1S1 Energy, Traive INC., OICO Holdings, Clarke Software and Global Dot, the latter acquired on June 5, 2023;

(4) The reconciliation of equity income from companies with shared control classified as joint ventures and associates with the amount presented in the income statement is presented below and results from the elimination of the results of CSN's transactions with these companies:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

(1) The operating margin of intercompany transactions with group companies classified as joint ventures, which are not consolidated, are reclassified in the Statement of Income from the Investment group to the costs and income tax and social contribution groups.

The changes in the Parent Company's investment are presented below:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

(1) On August 31, 2023, the reverse incorporation of CSN Cimentos into CSN Cimentos Brasil and the transfer of all assets, properties (movable and immovable), rights and obligations were approved.

The balance sheet and income statement balances of the companies with shared control are shown below and refer to 100% of the companies’ results:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

TSA is primarily engaged in the public service operation and development of a railroad network in the Northeast of Brazil, comprising the rail links Velha-Salgueiro, Salgueiro-Trindade, Trindade-Eliseu Martins, Salgueiro- Porto de Suape, and Missão Velha-Porto de Pecém (“Malha II”). On December 23, 2022, after extensive negotiations involving ANTT, TCU and the then Ministry of Infrastructure, signed first amendment to the Concession Agreement , which redefined the scope and deadlines for completion of the TLSA sections, notably to provide for the return of the section Salgueiro-Porto de Suape, which results in a project with the current 1,206 km of rail network and completion deadline up to December 2029.

Management relies on resources from its shareholders and third parties to complete the work, which is expected to be available, based on previously conducted agreements and recent discussions between the parties involved. After evaluating this matter, Management concluded that the use of the project’s business continuity accounting basis in the preparation of the interim financial information was considered appropriate.

On August 31, 2023, the reverse incorporation of CSN Cimentos into CSN Cimentos Brasil and the transfer of all assets, properties (movable and immovable), rights and obligations were approved. The Valuation Report of CSN Cimentos' net equity was prepared based on a specific balance sheet as of June 30, 2023.

As a result of the incorporation, the net equity of CSN Cimentos Brasil was increased by R$2,383,275,916.52 (two billion, three hundred and eighty-three million, two hundred and seventy-five thousand, nine hundred and sixteen reais and fifty-two cents), of which R$2,300,489,487.22 (two billion, three hundred million, four hundred and eighty-nine thousand, four hundred and eighty-seven reais and twenty-two cents) were allocated to the share capital and R$82,786,429.30 (eighty-two million, seven hundred and eighty-six thousand, four hundred and twenty-nine reais and thirty cents) to the capital reserve account.

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

The Machadinho Consortium is responsible for the exploration of HPP Machadinho, located on the Uruguay River, on the border of the states of Santa Catarina and Rio Grande do Sul, with an installed capacity of 1,140 MW and a physical guarantee of 519.8 average MW. CEEE-G's share in the Consortium was 5.53%, which implied the same percentage of costs and charges for the project under its responsibility.

As provided for in item 5.54 of the Privatization Notice of Auction Notice No. 01/2022 and under the terms of the contract establishing the Machadinho Consortium, the other consortium members exercised their right of preference to acquire the entire stake in CEEE-G. The sale of CEEE-G's stake in Consórcio Machadinho occurred after the parties agreed to all the terms and conditions of the definitive transaction documents and the usual conditions for closing.

Under the terms and conditions of the agreed contract, the completion of the transaction was subject to compliance with the Precedent Condition, with the closure subject to the parties obtaining prior approval from the National Electric Energy Agency – ANEEL to carry out the Transaction, the which was granted in August 2023. The Closing of the transaction was carried out on 09/29/2023, for the amount of R$ 114,763,385.98 (one hundred and fourteen million, seven hundred and sixty-three thousand, three hundred and eighty-five reais and ninety-eight cents).

The balance of investment properties is shown below:

Quarterly Financial Information – September 30, 2023 – Companhia Siderúrgica Nacional (CONVENIENCE TRANSLATION INTO ENGLISH FROM THE ORIGINAL PREVIOUSLY ISSUED IN PORTUGUESE)

The Company’s estimate of the fair value of investment properties was made for December 31, 2022. The fair value of investment property in the consolidated balance as of September 30, 2023, and December 31, 2022 is R$2,163,610 and in the parent company R$2,097,290.

The estimated average useful lives for the periods are as follows (in years):