Cosan S.A.

6-K 1 MainDocument.htm 6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Issuer

Pursuant To Rule 13a-16 Or 15d-16 of the

Securities Exchange Act of 1934

For the month of March 2026

Commission File Number: 333-251238

COSAN S.A.

(Exact name of registrant as specified in its charter)

N/A

(Translation of registrant’s name into English)

Av. Brigadeiro Faria Lima, 4100, – 16 th floor

São Paulo, SP 04538-132 Brazil

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40‑F:

Form 20-F ☒ Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Yes ☐ No ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Yes ☐ No ☒ cosan

Management Report 2025

Cosan S.A. (“Cosan” or “Company”) submits for consideration by its shareholders the Management Report regarding the activities performed in the fiscal year ended December 31, 2025. The results are presented in accordance with accounting practices adopted in Brazil and International Financial Reporting Standards (IFRS). Unless otherwise indicated, the comparisons presented in this report consider 2025 versus 2024.

The Company also provides a detailed version of its Financial Statements and its 4Q25 and 2025 earnings release on its website: https://www.cosan.com.br/en/

1. Management Message

We concluded 2025 amid a still challenging macroeconomic environment in Brazil. Despite this backdrop, we were able to take fundamental steps towards strengthening Cosan’s capital structure and reducing leverage. We completed the capitalization process and welcomed new strategic shareholders, reinforcing our governance framework and providing long-term capital stability.

Across our business portfolio, following a year marked by significant challenges, our controlled companies demonstrated resilience and adaptability in their operational results, which are detailed in Section C. Portfolio Performance of the 4Q25 and 2025 earnings release.

We started 2026 with a simplified organizational structure and the execution of debt prepayments totaling approximately R$6.2 billion. At Compass, we announced the intention to carry out a secondary public equity offering, with a focus on further advancing the reduction of Cosan’s indebtedness.

2. Annual Results

Cosan Consolidated

Below we present Cosan’sconsolidated accounting results for 2025 and its business units. With the exception of Raízen (a joint venture formed between Cosan and Shell which is accountedvia equity pickup method), all other information reflects the full consolidation (100%) of the subsidiaries’ results, regardless of Cosan’sstake. For further information, see Note 9 – “Investment in Subsidiaries and Associates” of the individual and consolidated financial statements as of December 31, 2025 (“Financial Statements”).

It is important to clarify that the Cosan Corporate segment represents the Company’s corporate structure, which comprises: (i)senior management and corporate teams that incur G&A and other operating expenses (revenues), including pre-operating investments; (ii) equity pickup results from investments; and (iii) financial results attributable to cash and debt at the holding company level, intermediate holding companies (Cosan Nove and Cosan Dez), and offshore financial entities, among other expenses, as detailed in Notes 1 and 4 to the Financial Statements. The tables below reflect thecomplete information disclosed in the Company’s Financial Statements.

Information by Segment:

Note: Although Raízen SA is a joint venture recorded using the equity method and is not proportionally consolidated, Management continues to review the information by segment. The reconciliation of these segments is presented in the column "Deconsolidation of a Joint Venture".

Below we present the material changes in the income statement:

Net Revenue

Cosan’s consolidated net operating revenue totaled R$40.4 billion in 2025, representing an 8% decrease compared to 2024. The main factors contributing to this variation by segment are described below:

Rumo recorded net operating revenue of R$13.8 billion in 2025, remaining virtually stable compared to 2024, due toa combination of operational and market-related factors. Performance reflected higher transported volumes, despite a reduction in the average tariff. The main growth driver was the Northern Operation, with emphasis on the contribution from new logistics flows of pulp, liquid fuels, and bauxite, as well as higher volumes transported in the grain portfolio.

At Compass, net operating revenue totaled R$16.6 billion in 2025, 10%lower in comparison to R$18.4 billion in 2024, mainly reflecting the migration of customers from the regulated market to the free market.

Moove reported net operating revenue of R$9.3 billion in 2025, a 9% decreasev ersus the prior year. This performance was primarily impacted by lower lubricant sales, reflecting operational impacts resulting from the fire at the Rio de Janeiro plant. Despite the adverse scenario, the company sought to mitigate impacts through portfolio management strategies and optimization of the product mix, aiming to maintain competitiveness and operational efficiency.

At Radar, net operating revenue reached R$654 million in 2025, representing a reduction compared to R$1.4 billion in 2024, mainly reflecting the lower number of agricultural properties sold from the portfolio compared to the previous year.

Cost of sales

The cost ofsales provided by Cosan’s subsidiaries totaled R$27.2 billion in thefiscal year ended, representing a 10% decrease compared to 2024. This reduction mainly reflects: (i) at Compass, the impact of customer migration from the regulated to the free market; (ii) at Radar, an 89% reduction in operating costs due to the lower number of agricultural property sales in 2025; and (iii) at Moove, a 4% decrease in operating costs, reflecting the impacts of the fire that occurred in 2025 at the Rio de Janeiro plant.

Gross profit

Based on the results presented, Cosan recorded gross profit of R$13.2 billion in 2025, 4%lower than the previous year. This decline was mainly driven by the performance of the Moove segment, which was significantly impacted as described above. Additionally, the Radar segment also contributed to the reduction in gross profit due toa reduction in the number of agricultural property sales during the year compared to the prior year.

Selling, General, Administrative Expenses, Other operating income (expenses) and Impairment

Consolidated selling, general and administrative expenses, other operating income (expenses), and impairment losses totaled R$ 2.7 billion in 2025, representing a reduction compared to the prior period, mainly impacted by the following factors:

At Rumo, selling, general and administrative expenses, other operating income (expenses), and impairment losses totaled R$1.8 billion in 2025 (-55%). This performance reflects continuous control of fixed costs and efficiency gainsin personnel and operational management, in line with the company’s operational discipline and cost optimization strategy. Additionally, results were positively impacted by compensation for loss of profits related to the Southern Operation, recognition of tax credits, and impairment losses.

At Moove, selling, general and administrative expenses and other income totaled R$1.3 billion in 2025, with the reduction mainly driven by the other income line, reflecting the receipt of compensation for lost profits and property damage related to the fire that occurred in early 2025 at the Rio de Janeiro plant.

At Cosan Corporate, selling, general and administrative expenses, other operating income (expenses), and impairment losses totaled R$401.2 million, representing a 54% decrease compared to the same period of the previous year, mainly due to: (i) reduction in costs associated with the Long-Term Incentive Program, reflecting the decline in the share price; (ii) the the accrual of cost sharing from businesses activities centrally performed; and (ii) the impact of the partial divestment of the stake in Vale carried out in 2024.

Financial Result

In 2025, Cosan’s consolidated financial result totaled an expense of R$7.8 billion, compared to an expense of R$8.8 billion in 2024. This reduction is mainly explained by:

At Rumo, the financial result totaled R$3.0 billion (+17%), mainly impacted by the higher net debt cost, reflecting increased leverage and the effect of a higher average CDI. Higher interest rates also contributed to an increase in the monetary variation of concession liabilities. Other financial income was positively impacted by higher capitalization of interest on ongoing investment projects.

At Compass, the financial result reached R$ 1.6 billion in 2025, representing a 92% increase versus the prior year, mainly driven by higher debt costs, increased interest rates, and a non-recurring effect in 2024, as detailed in Note 32 to Compass’ Financial Statements.

At Cosan Corporate, the financial result amounted to R$2.9 billion in 2025, a 44% decrease compared to 2024, mainly reflecting:

(i) the positive result from foreign exchange variation on bonds and the lower impact of interest expenses, thanks to the reduction in gross debt; and (ii) higher cash balance resulting from the follow-on offering at Cosan and the sale of a partial stake in Rumo, carried out in November and December 2025, respectively, in addition to a higher interest rate environment.

Equity Pickup

Equity pickup results were negative R$10.7 billion in 2025, compared to negative R$4.2 billion in 2024, mainly due to the non-recurring and non-cash recognition of impairment losses on certain Raízen’s assets, recordeddue to the application of accounting procedures arising from significant uncertainty regarding its ability to continue (going concern).

Income Tax and Social Contribution

As of December 31, 2025, income tax and social contribution expenses totaled R$2.2 billion, 31%lower in compa rison to R$3.2 billion in 2024. The effective tax rate was 27.6% in 2025, compared to 60.8% in the prior year. This reduction mainly reflects tax losses and unrecognized temporary differences totaling R$2.4 billion, representing a 44% decrease compared to 2024, which also included the write-off of tax losses from prior periods at the parent company level.

Profit (loss)

Cosan ended 2025 with a consolidated net loss of R$10.2 billion, representing a negative variation of R$2.0 billion compared to 2024, mainly reflecting the accounting recognition of the recoverable amount of certain assets at Raízen.

3. Proposal for allocation of the Company'sresults for thef iscalyeare nded December 31, 2025

The allocation of results will be submitted for deliberation at the next Annual General Meeting, in accordance with Note 17 to the Financial Statements.

4. Human capital

Safety and well-being remain priorities for the Company, with a permanent ambition of zero accidents. In this context, the LTIF¹ safety indicator was 0.282 in 2025, remaining stable compared to 2024. Cosan and its investee companies continue to focus on maintaining high safety standards in their operations, with ongoing investments in training, technology, and safe practices, as well as health benefits that reinforce care for people’s physical and mental well-being.

The Development agenda was strengthened through structured programs and initiatives aimed at expanding capabilities, developing leadership, and supporting employee growth, connecting people development with the Company’s strategic business priorities.

In terms of Diversity, partnerships with the Forum of Companies and LGBTI+ Rights and the Business Initiative for Racial Equality were maintained, and a new partnership was established with Movimento Mulher 360º, further strengthening the Company’s actions related to equity and inclusion.

At the end of 2025, Cosan’s administrative structure underwent a simplification process, resulting in a significant reduction in headcount. This movement led to a greater transfer of activities from the holding company to the operating entities.

In compliance with Law No. 15,177/2025, which amends Law No. 6,404/1976, the Company presents:

Note: (1) Amounts consider annual compensation, including an estimate of short-term variable compensation. To ensure comparability, only employees who worked the full 12 months of the year were considered. There are differences in hierarchical level, seniority, tenure, performance, among other factors, among employees grouped within the same classification. The segmentation considers a minimum number of employees of both genders in each group; however, highly specific roles in which there are employees of only one gender were not included.

Note:(2) Lost time injury frequency = Number of accidents per million hours worked.

Cosan reiterates its commitment to promoting gender equity, in line with the guidelines of its Diversity, Equity and Inclusion Policy, and reinforces that it fosters an internal culture that promotes and respects the values and needs of all people, without distinction of color, gender, religion, culture, sexual orientation, physical condition, appearance, or age.

5. Capital Market & Corporate Governance

In 2005, Cosan entered the capital markets, with its shares listed on the Novo Mercado segment of B3 S.A. – Brasil, Bolsa, Balcão (“B3”), under the ticker CSAN3. Cosan also has American Depositary Shares (ADSs) traded on the New York Stock Exchange (NYSE) since March 2021.

In November 2025, the Company’s controlling shareholders, Aguassanta Investimentos S.A. and Queluz Holding Limited, investment vehicles of the family of Mr. Rubens Ometto Silveira Mello, entered into a shareholders’ agreement with BTG Pactual Holding and Perfin Infraestrutura (together, the “Investors”), and the Company also carried out two primary public offerings of common shares, raising R$ 10.5 billion, with the objective of strengthening its capital structure and reducing holding company indebtedness. The new Investors are strategic business groups with diversified investments, including in infrastructure, and aim to contribute to the enhancement of corporate governance and to the execution of the Company’s long-term strategy.

Following the public offerings mentioned above, as of December 31, 2025, Cosan’s share capital was represented by 3,966,570,932 registered, book-entry common shares with no par value, all of which carry voting rights, in accordance with the Novo Mercado regulations of B3.

Management remains committed to the continuous evolution of the Company’s governance environment. The Board of Directors is supported by committees that address the Company’s priority matters, including the Fiscal Council and the Statutory Audit Committee, both of which operate independently from Management. Cosan also has a dedicated area responsible for risk management, information security, internal controls, and internal audit, which strengthens governance at the holding company level and provides support to the companies in our portfolio.

In addition, Cosan adopts best market practices and procedures with the objective of complying with applicable legislation and regulations, as well as with the rules set forth in its Code of Conduct and policies related to the prevention, detection, and mitigation of misconduct, fraud, corruption, bribery, irregularities, and unlawful acts, especially in dealings with the Public Administration. The Code of Conduct is available on the Company’s website (https://www.cosan.com.br/en/).

6. Commitment to Sustainability

Cosan annually discloses environmental, social, and governance (ESG) information through its Sustainability Report, presenting priority topics in accordance with its materiality matrix, in addition to addressing matters such as risk management. Since 2023, the reporting of annual sustainability information has followed the format of Cosan’s Integrated Report, in compliance with CVM Resolution No. 14/20.

In June 2023, the International Sustainability Standards Board (ISSB) issued IFRS S1 – General Requirements for Disclosure of Sustainability-related Financial Information and IFRS S2 – Climate-related Disclosures, which establish new disclosure requirements regarding, respectively, sustainability-related risks and opportunities and climate-related disclosures. The Company is taking the necessary measures to comply with these standards, whose adoption is required for fiscal years beginning on or after January 1, 2026, pursuant to CVM Resolution No. 193, issued in October 2023.

Cosan has also been a signatory to the United Nations Global Compact since 2020 and has been recognized in leading ESG benchmarks: (i) by the Carbon Disclosure Project (CDP), the Company advanced to an “A” score in CDP Climate, one of the world’s leading references for transparency and climate risk management; and (ii) by S&P Global, the Company was once again included in the “Sustainability Yearbook 2026”, being recognized as one of the top-performing companies in its sector based on its S&P Global ESG Score.

7. Investments in subsidiaries and associates

In accordance with Article 243 of Law No. 6,404/1976, the Company reports that it holds material investments in subsidiaries and associates operating in strategic areas of its business. These investments are recordedon the balance sheet and detailed in Note 9 to the Financial Statements, which presents the composition of the portfolio and the respective interests.

Investments in subsidiaries and associates are accounted for using the equity pick upmethod, whereby the Company’s share in the results and changes in equity of these investees is recognized proportionally in its financial statements. The main companies that comprise this portfolio, as well as the respective amounts invested, are disclosed in the balance sheet and are summarized in the investment table below.

8. Relationship with the Independent Auditor

Cosan engaged PricewaterhouseCoopers Auditores Independentes Ltda. (PwC) to provide external audit services for its financial statements for the fiscal year 2025.

The Company has a Policy on the Engagement of Independent Auditors and Non-Audit Services (“Policy”) aimed at establishing rules related to the engagement of independent auditors and audit firms, including guidelines and procedures to ensure the independence of independent auditors and consulting service providers of the Company, its controlled entities, subsidiaries, joint ventures, and relevant associates. The Policy is available at: https://www.cosan.com.br/en/about-cosan/corporate-governance/bylaws-policies-and-codes/.

During 2025, PwC was also engaged to provide other independent audit services related to subsidiaries and associates, including the annual audit of the individual and consolidated financial statements for the year ended December 31, 2025, as well as the review of the Company’s interim individual and consolidated financial statements for the periods ended March 31, June 30, and September 30, 2025. Such services did not result in any implications for the independence principle established in the Policy.

Based on these principles, PwC has informed that the provision of the services described above does not affect the independence and objectivity required for the performance of the services rendered to the Company.

9. Management Declaration

In compliance with the provisions of CVM Resolution No. 80, Management declares that it has discussed, reviewed, and agreed with the Financial Statements for the fiscal year ended December 31, 2025, as well as with the opinions expressed in the independent auditors’ report on the Company’s Financial Statements.

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