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 2, 2026

2. SEC Identification Number

0000091447

3. BIR Tax Identification No.

0001903240000

4. Exact name of issuer as specified in its charter

Semirara Mining and Power Corporation

5. Province, country or other jurisdiction of incorporation

Philippines

6. Industry Classification Code(SEC Use Only)

7. Address of principal office

2/F DMCI Plaza, 2281 Don Chino Roces Avenue, Makati City Postal Code 1231

8. Issuer's telephone number, including area code

8246-2280/8246-2238

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	4,250,547,620

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.

Semirara Mining and Power CorporationSCC

PSE Disclosure Form 4-31 - Press Release References: SRC Rule 17 (SEC Form 17-C)
Section 4.4 of the Revised Disclosure Rules

Subject of the Disclosure
SMPC aligns workforce as seawater inflows limit Acacia operations
Background/Description of the Disclosure
Semirara Mining and Power Corporation (SMPC) has been managing seawater entering its Acacia mine. Despite ongoing efforts to control these inflows, the flow rate has increased to approximately 30,000 cubic meters per hour—enough to fill 12 Olympic-sized swimming pools every hour. This volume exceeds current pumping capacity and heightens the risk of flooding at Acacia. Managing these seawater inflows over the longer term requires substantial investment in pumping equipment, power systems and other infrastructure. Uncertainty surrounding the coal bid round complicates planning for these investments. Without adequate capital spending, the risk of flooding and losing access to Acacia’s remaining coal reserves increases. These conditions have limited operations and led to the partial suspension of stripping activities at the Acacia mine, which are needed to access coal for future production. Management is therefore aligning manpower with reduced operating requirements through a supplemental redundancy program affecting 996 employees. SMPC recognizes the impact on affected employees and their families and is committed to supporting them through the transition. SMPC’s 2026 coal production target remains at 12 million metric tons. Disrupted stripping activities at Acacia will affect 2027 production, as the mine was expected to supply most of next year’s coal output. The Department of Energy (DOE) conducted a site visit at Acacia from September 24 to 26. SMPC continues to coordinate with the DOE on the mine’s operating challenges and longer-term options.
Other Relevant Information
See SEC Form 17-C.