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)

Sep 23, 2026

2. SEC Identification Number

A1996-11593

3. BIR Tax Identification No.

005-038-428-000

4. Exact name of issuer as specified in its charter

MANILA WATER COMPANY, INC.

5. Province, country or other jurisdiction of incorporation

Philippines

6. Industry Classification Code(SEC Use Only)

7. Address of principal office

MWSS Administration Building, No. 489 Katipunan Road, Balara, Quezon City Postal Code 1105

8. Issuer's telephone number, including area code

09171547921

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	2,606,510,172
Preferred	3,563,756,068

11. Indicate the item numbers reported herein

9

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.

Manila Water Company, Inc.MWC

PSE Disclosure Form 9-1 - Share Buy-Back Transactions References: Section 9 of the Revised Disclosure Rules

Subject of the Disclosure
Share Buy-Back Transaction
Background/Description of the Disclosure
Manila Water Company, Inc. purchased common shares today, as disclosed below.

Type of Securities

• Common
• Preferred-
• Others-

Details of Share Buy-Back Transaction(s)

Date of Transaction	Number of Shares Purchased	Price Per Share
Sep 23, 2026	96,000	33.90
Sep 23, 2026	104,000	33.95
Sep 23, 2026	400,000	34.00
	600,000

Effects on Number of Shares

	Before	After
Outstanding Shares	2,606,510,172	2,605,910,172
Treasury Shares	279,285,725	279,885,725

Cumulative Number of Shares Purchased to Date 1	1,850,000
Total Amount Appropriated for the Buy-Back Program	105,000,000.00
Total Amount of Shares Repurchased	64,225,455.00

Other Relevant Information
-

¹ From the date when the share buy-back program commenced.