SECURITIES AND EXCHANGE COMMISSIONSEC FORM 17-C

CURRENT REPORT UNDER SECTION 17
OF THE SECURITIES REGULATION CODE
AND SRC RULE 17.2(c) THEREUNDER

1. Date of Report (Date of earliest event reported)

Oct 7, 2026

2. SEC Identification Number

37535

3. BIR Tax Identification No.

37535

4. Exact name of issuer as specified in its charter

ATN HOLDINGS, INC.

5. Province, country or other jurisdiction of incorporation

Mandaluyong, Philippines

6. Industry Classification Code(SEC Use Only)

7. Address of principal office

9th Floor Summit One Tower 530 Shaw Boulevard, Mandaluyong City Postal Code 1550

8. Issuer's telephone number, including area code

(632) - 7717-0523

9. Former name or former address, if changed since last report

n/a

10. Securities registered pursuant to Sections 8 and 12 of the SRC or Sections 4 and 8 of the RSA

Title of Each Class	Number of Shares of Common Stock Outstanding and Amount of Debt Outstanding
Common	6,825,055,429

11. Indicate the item numbers reported herein

1

The Exchange does not warrant and holds no responsibility for the veracity of the facts and representations contained in all corporate disclosures, including financial reports. All data contained herein are prepared and submitted by the disclosing party to the Exchange, and are disseminated solely for purposes of information. Any questions on the data contained herein should be addressed directly to the Corporate Information Officer of the disclosing party.

ATN Holdings, Inc.ATN

PSE Disclosure Form 4-19 - Declassification of Shares References: SRC Rule 17 (SEC Form 17-C) and
Section 4.4 of the Revised Disclosure Rules

Subject of the Disclosure
SEC Approval - Declassification of Class “A” and Class “B” Common Shares
Background/Description of the Disclosure
Pursuant to SEC Memorandum Circular No. 10, Series of 2025, the Corporation undertook the declassification of its Class “A” and Class “B” common shares into a single class of common shares. The amendment was approved by the Board on 29 September 2025, ratified by the stockholders on 13 November 2025, and approved by the SEC on 06 October 2026.

Date of Approval by Board of Directors	Sep 29, 2025
Date of Approval by Stockholders	Nov 13, 2025
Date of Approval by Securities and Exchange Commission	Oct 6, 2026

Reason or purpose of the declassification of shares
To comply with SEC Memorandum Circular No. 10, Series of 2025 and promote a single-class common share structure for the Corporation’s listed common equity.

Effects on Capital Structure

Issued Shares

Type of Security/Stock Symbol	Before	After
Common - ATN	4,025,055,429	6,825,055,429
Common- ATNB	2,800,000,000	0

Outstanding Shares

Type of Security/Stock Symbol	Before	After
Common- ATN	4,025,055,429	6,825,055,429
Common- ATNB	2,800,000,000	0

Treasury Shares

Type of Security/Stock Symbol	Before	After
n/a	0	0

Listed Shares

Type of Security/Stock Symbol	Before	After
Common- ATN	4,025,055,429	6,825,055,429
Common- ATNB	2,800,000,000	0

Procedure(s) for updating stock certificates

Details of Stock Transfer Agent

Name	Stock Transfer Service, Inc.
Address	6784, Unit D, 34th Floor, Rufino Pacific Tower, Ayala Avenue, Makati City, 1200 Metro Manila
Contact Person	Mr. Richard D. Regala Jr., General Manager

Inclusive dates when the old stock certificates can be replaced

Start Date	TBA
End Date	TBA

Documentary requirements

Individual Shareholders
to be announced
Corporate Shareholders
to be announced

Date of availability of new stock certificates	TBA

Procedures in case of lost stock certificates
to be announced
Other Relevant Information
Attachments: SEC Certificate of Filing of Amended Articles of Incorporation dated 06 October 2026; SEC-approved Amended Articles of Incorporation.