# EDGAR Filing Document

**Accession Number:** 0001430162
**File Stem:** 0001554855-25-001899
**Filing Date:** 2025-10
**Character Count:** 4420
**Document Hash:** f246efc58793e120169c451a30b81f0d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001554855-25-001899.hdr.sgml**: 20251031

**ACCESSION NUMBER**: 0001554855-25-001899

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20251030

**FILED AS OF DATE**: 20251031

**DATE AS OF CHANGE**: 20251030

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Cosan S.A.
- **CENTRAL INDEX KEY:** 0001430162
- **STANDARD INDUSTRIAL CLASSIFICATION:** RETAIL-AUTO DEALERS & GASOLINE STATIONS [5500]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 000000000
- **STATE OF INCORPORATION:** D5
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-40155
- **FILM NUMBER:** 251437659

**BUSINESS ADDRESS:**
- **STREET 1:** AV. BRIGADEIRO FARIA LIMA
- **STREET 2:** 4100, 16TH FLOOR
- **CITY:** SAO PAULO, SP
- **STATE:** D5
- **ZIP:** 04538-132
- **BUSINESS PHONE:** 55-11-3897-9797

**MAIL ADDRESS:**
- **STREET 1:** AV. BRIGADEIRO FARIA LIMA
- **STREET 2:** 4100, 16TH FLOOR
- **CITY:** SAO PAULO, SP
- **STATE:** D5
- **ZIP:** 04538-132

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Cosan S.A. Industria e Comercio
- **DATE OF NAME CHANGE:** 20080319

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 October 2025

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**<br>São Paulo, SP 04538-132 Brazil<br>(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 ☒

------

![Graphics](cb6a2c99ccb1a89609e6.jpg)

**COSAN S.A.**

CNPJ No. 50.746.577/0001-15

NIRE 35.300.177.045

Publicly-held company

CVM Code 19836

**<u>MATERIAL</u> <u>FACT</u>**

**COSAN** **S.A. (B3: CSAN3; NYSE: CSAN)** ("Cosan" or "Company"), in compliance with the provisions of CVM Resolution No. 44, of August 23, 2021, in the context of the Material Fact disclosed on September 21, 2025, hereby informs its shareholders and the market in general that the Conselho Administrativo de Defesa Econômica ("CADE") has approved without restrictions the subscription of shares issued by Cosan, by the funds Perfin Rally Fundo de Investimento em Participações Multiestratégia Responsabilidade Limitada, Classe Única BTG Pactual Infraestrutura III Fundo de Investimento em Participações Multiestratégia, and Classe Única Fundo de Investimento em Participações BPAC3 - Multiestratégia Responsabilidade Limitada (collectively, "Investors"). The eventual subscription of the shares by the Investors, under the terms of the Investment Agreement, depends on the conclusion and allocation in the first public offering in progress.

CADE's decision is still awaiting the expiration of the legal period of 15 days, under the terms of the applicable legislation.

The Company will keep its shareholders and the market informed about the conclusion of the first public offering, whose closing of the *Bookbuilding* Procedure is expected to take place on November 3, 2025, pursuant to the law and CVM regulations. More information may be obtained in due course on the CVM (www.gov.br/cvm) and the Company's Investor Relations (www.cosan.com.br) websites.

São Paulo, October 30, 2025.

**Rodrigo Araujo Alves** 

Chief Financial and Investor Relations Officer

------

**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: October 30, 2025

---

| | |
|:---|:---|
| &nbsp;&nbsp; COSAN S.A. | &nbsp;&nbsp; COSAN S.A. |
| &nbsp;&nbsp; By: | &nbsp;&nbsp; /s/ Rodrigo Araujo Alves |
|  | Name:Rodrigo Araujo Alves |
|  | Title:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Chief Financial Officer |

---