Cosan (NYSE: CSAN) trims Compass stake in BRL 2.15B share sale

Rhea-AI Filing Summary

Cosan S.A. priced and sold 76,785,715 common shares of its subsidiary Compass Gás e Energia in a secondary public offering at BRL 28.00 per share, raising BRL 2,150,000,020.00 for Cosan. The overall offering, including other selling shareholders, totaled 100,892,857 shares for BRL 2,824,999,996.00.

Cosan also granted the stabilizing agent an over-allotment option of up to 13,392,857 additional Compass shares at the same price. If fully exercised, total offering proceeds may reach BRL 3,199,999,992.00, with Cosan receiving BRL 2,525,000,016.00. Cosan’s ownership in Compass will fall from 88% to 77.25%, and potentially to 75.37%, while it remains the controlling shareholder together with Cosan Dez Participações S.A.

Insights

Equity capital markets analyst

Cosan monetizes part of its Compass stake while keeping control.

Cosan is using a secondary public offering of Compass shares to unlock BRL 2,150,000,020.00 of value, potentially rising to BRL 2,525,000,016.00 if the over-allotment is fully exercised. All proceeds described here go to Cosan as a selling shareholder, not to Compass.

Post-transaction, Cosan’s direct and indirect stake in Compass declines from 88% to 77.25%, and may reach 75.37% with full over-allotment. Despite this dilution of its ownership percentage, Cosan, together with Cosan Dez Participações S.A., remains Compass’ controlling shareholder according to the disclosure.

The transaction introduces more Compass shares into the market through a bookbuilding-led offering and a stabilization mechanism via over-allotment. The actual impact on Cosan’s balance sheet, leverage, and capital allocation will depend on how it ultimately uses the cash proceeds, which is not detailed in the provided text.

Key Figures

Cosan shares sold: 76,785,715 shares Price per Compass share: BRL 28.00 per share Cosan base proceeds: BRL 2,150,000,020.00 +5 more

8 metrics

Cosan shares sold 76,785,715 shares Compass common shares in secondary public offering

Price per Compass share BRL 28.00 per share Set after bookbuilding procedure

Cosan base proceeds BRL 2,150,000,020.00 Proceeds to Cosan from base offering

Total base offering size BRL 2,824,999,996.00 All selling shareholders in Compass offering

Potential total offering size BRL 3,199,999,992.00 If over-allotment shares fully placed

Cosan stake post-offering 77.25% Compass ownership after base offering

Cosan stake with full over-allotment 75.37% Compass ownership if all over-allotment shares sold

Over-allotment shares 13,392,857 shares Additional Compass shares held by Cosan for stabilization

Key Terms

secondary public offering, Bookbuilding Procedure, stabilizing agent, Over-Allotment Shares, +1 more

5 terms

secondary public offering financial

"the pricing of the secondary public offering of common shares issued by Compass"

A secondary public offering is when a company sells additional shares to the public after its initial sale, often to raise more money or allow early investors to cash out. For investors, it can impact the stock's price by increasing the number of shares available, potentially making the stock more or less valuable depending on demand.

Bookbuilding Procedure financial

"at a price per Share of BRL 28.00, set after the conclusion of the Bookbuilding Procedure"

stabilizing agent financial

"Cosan granted to the stabilizing agent an option for a over-allotment lot"

Over-Allotment Shares financial

"intended exclusively for the activity of stabilizing the price of the Shares within the scope of the Offering ("Over-Allotment Shares")"

controlling shareholder financial

"with Cosan, together with Cosan Dez Participações S.A., remaining as Compass' controlling shareholder"

A controlling shareholder is a person or entity that holds enough voting power in a company—often a majority of votes or decisive influence through agreements—to determine its board, strategy and major decisions. For investors this matters because that control shapes corporate direction, risk and who benefits from deals; like a driver steering a car, a controlling shareholder can speed up or block changes, which can affect minority shareholders’ returns and the company’s value.

Form 6-K: How Foreign Companies Report to the SEC →

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16
OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2026

Commission File Number: 001-40155

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, – 16th 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 X Form 40-F

COSAN S.A.

CNPJ No. 50.746.577/0001-15

NIRE 35.300.177.045

Publicly-held company

CVM Code 19836

MATERIAL FACT

COSAN S.A. (B3: CSAN3; NYSE: CSAN) ("Cosan" or "Company"), pursuant to CVM Resolution No. 44 and Article 157, paragraph 4, of Brazilian Law No. 6,404/76, and further to the Material Facts disclosed on February 23, 2026, March 5, 2026 and April 27, 2026, hereby informs its shareholders and the market in general of the pricing of the secondary public offering of common shares issued by Compass Gás e Energia S.A. ("Compass" and "Shares", respectively) and held by the Company and the other selling shareholders indicated in the Final Brazilian Prospectus ("Offering").

In this context, Cosan's Board of Directors approved, on this date, the sale, within the scope of the Offering, of 76,785,715 Shares held by it, at a price per Share of BRL 28.00, set after the conclusion of the Bookbuilding Procedure, resulting in a total amount of BRL 2,150,000,020.00 for the Company. The Offering totalized 100,892,857 Shares sold by Cosan and other selling shareholders, representing a total amount of BRL 2,824,999,996.00.

In addition, Cosan granted to the stabilizing agent an option for a over-allotment lot of up to 13,392,857 Shares held by Cosan, equivalent to up to 15% of the total Shares of the base Offering, under the same conditions and at the same Price per Share, intended exclusively for the activity of stabilizing the price of the Shares within the scope of the Offering ("Over-Allotment Shares”). If the Over-Allotment Shares are fully placed, the total amount of the Offering may reach up to BRL 3,199,999,992.00, with Cosan having received BRL 2,525,000,016.00.

As a result of the Offering, Cosan's direct and indirect ownership in Compass' capital stock, currently equivalent to 88%, will be 77.25%, and may be reduced to 75.37% in case of full placement of the Over-Allotment Shares, with Cosan, together with Cosan Dez Participações S.A., remaining as Compass' controlling shareholder.

Cosan will keep its shareholders and the market in general duly informed about the progress of the Offering, in accordance with the applicable regulations.

This Material Fact is for informational purposes only and does not constitute an offer to sell or a solicitation of an offer to buy securities in Brazil, the United States or any other jurisdiction. The Offering and the securities described in this material fact have not been and will not be registered under the U.S. Securities Act of 1933, as amended (the “Securities Act”) or any other U.S. federal or state securities law, and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements under the Securities Act. The Offering and the Shares will not be registered with any securities regulatory authority, except in Brazil with the CVM and ANBIMA. This Material Fact shall not, under any circumstances, be considered and/or construed as, nor constitute, an investment recommendation or offer to sell, solicitation or offer to buy any securities issued by the Company or Compass.

São Paulo, May 7, 2026

Rafael Bergman

Chief Financial and Investor Relations Officer

JUR_SP - 57764736v6 - 599057.56897

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:  May 7, 2026

	COSAN S.A.
	By:	/s/ Rafael Bergman
		Name:            Rafael Bergman
		Title: Chief Financial Officer

FAQ

What secondary offering did Cosan (CSAN) announce involving Compass shares?

Cosan announced a secondary public offering of Compass common shares it holds. The company is selling 76,785,715 Compass shares at BRL 28.00 each, as part of a larger offering totaling 100,892,857 shares sold by Cosan and other shareholders.

How much cash will Cosan (CSAN) receive from selling Compass shares?

Cosan expects to receive BRL 2,150,000,020.00 from the base offering. If the stabilizing agent fully exercises the over-allotment option for up to 13,392,857 additional shares, Cosan’s proceeds could increase to BRL 2,525,000,016.00.

At what price were the Compass shares sold in Cosan’s offering?

The Compass shares were priced at BRL 28.00 per share. This price was set after completion of a bookbuilding process and applies to both the base shares sold in the offering and any over-allotment shares placed by the stabilizing agent.

How does the Compass share sale affect Cosan’s ownership stake?

Cosan’s ownership in Compass will decrease but it will remain the controller. The stake falls from 88% to 77.25% after the base offering, and may decline further to 75.37% if the full over-allotment of shares is exercised.

What is the total size of the Compass share offering mentioned by Cosan?

The total base offering amounts to BRL 2,824,999,996.00. This corresponds to 100,892,857 Compass shares sold by Cosan and other selling shareholders. With full over-allotment, the total offering value may reach BRL 3,199,999,992.00.

Are the Compass shares in Cosan’s offering registered in the United States?

No, the Compass shares are not registered under the U.S. Securities Act. They may not be offered or sold in the United States without registration or an applicable exemption, and the offering is registered only in Brazil with the CVM and ANBIMA.