# EDGAR Filing Document

**Accession Number:** 0001073404
**File Stem:** 0001104659-26-044431
**Filing Date:** 2026-4
**Character Count:** 4780
**Document Hash:** 82a8d034263b9b7e9f64f279cd30dc77
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-044431.hdr.sgml**: 20260416

**ACCESSION NUMBER**: 0001104659-26-044431

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 3

**CONFORMED PERIOD OF REPORT**: 20260416

**FILED AS OF DATE**: 20260416

**DATE AS OF CHANGE**: 20260416

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** GERDAU S.A.
- **CENTRAL INDEX KEY:** 0001073404
- **STANDARD INDUSTRIAL CLASSIFICATION:** STEEL WORKS, BLAST FURNACES & ROLLING & FINISHING MILLS [3310]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 000000000
- **STATE OF INCORPORATION:** D5
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-14878
- **FILM NUMBER:** 26868228

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** AV DOUTORA RUTH CARDOSO, 8,501
- **STREET 2:** 8TH FLOOR
- **CITY:** SAO PAULO, SP
- **PROVINCE COUNTRY:** D5
- **ZIP:** 05425-070
- **BUSINESS PHONE:** 011-55-51-3323-2703

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** AV DOUTORA RUTH CARDOSO, 8,501
- **STREET 2:** 8TH FLOOR
- **CITY:** SAO PAULO, SP
- **PROVINCE COUNTRY:** D5
- **ZIP:** 05425-070

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** GERDAU SA
- **DATE OF NAME CHANGE:** 19981112

**U.S. 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**

Dated April 16, 2026

Commission File Number 1-14878

**GERDAU S.A.**

(Translation of Registrant's Name into English)

Av. Dra. Ruth Cardoso, 8,501 – 8° andar

São Paulo, São Paulo - Brazil CEP 05425-070

(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 ◻

<u>Exhibit Index</u>

<u>Exhibit</u> <u>Description of Exhibit</u> <br>[99.1](tm2612024d1_ex99-1.htm) [Notice to the Market – Binding Proposal for Acquisition of Equity Stake](tm2612024d1_ex99-1.htm)

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: April 16, 2026

---

| | |
|:---|:---|
| GERDAU S.A. | GERDAU S.A. |
| By: | /s/ Rafael Dorneles Japur |
| Name: | Rafael Dorneles Japur |
| Title: | Vice-President and Investor Relations Officer |

---

## Exhibit 99.1

**Exhibit 99.1**![](tm2612024d1_ex99-1img001.jpg)

**GERDAU S.A.**

Corporate Tax ID (CNPJ/MF): 33.611.500/0001-19

Registry (NIRE): 35300520696

**NOTICE TO THE MARKET**

**Gerdau S.A.** (B3: GGBR / NYSE: GGB) ("Company") hereby informs its shareholders and the market in general that it has submitted a binding proposal for the acquisition of the entire equity interest in Dona Francisca Energética S.A. ("DFESA"), corresponding to 23.03% of its share capital, currently held by Centrais Elétricas de Santa Catarina S.A. ("CELESC"). The proposal contemplates an enterprise value of R$150 million and was accepted by CELESC on this date.

The acquisition price will be paid in cash on the closing date, using the Company's own available resources. The purchase price is subject to customary closing adjustments in accordance with the terms and conditions set forth in the definitive agreements. The transaction is also subject to the potential exercise of the proportional preemptive rights held by the other shareholders of DFESA. Additionally, closing of the transaction is subject to the satisfaction of customary conditions precedent for transactions of this nature, including approval by the Brazilian antitrust authority.

DFESA is a privately held corporation engaged in electric power generation. It holds an 85% ownership interest in the consortium responsible for the concession of the Dona Francisca Hydroelectric Power Plant, located on the Jacuí River, State of Rio Grande do Sul, between the municipalities of Agudo and Nova Palma. The plant has an installed capacity of 125 MW and a firm energy output of 72.5 average MW, of which approximately 66 average MW are allocated to DFESA.

Currently, Gerdau holds 53.94% of DFESA's share capital, corresponding to 35.6 average MW of energy. Upon completion of the acquisition, the Company will hold a 76.97% equity interest in DFESA, totaling approximately 50 average MW of firm energy.

This acquisition is aligned with Gerdau's strategy to enhance cost competitiveness by increasing its self-production of clean energy, consistent with the Company's decarbonization commitments.

São Paulo, April 16, 2026.

**Rafael Dorneles Japur**

Vice-President and

Investor Relations Officer