Aboitiz Equity Ventures, Inc. remained the country's biggest power generation group this year, but its 24.3-percent national market share has brought it within striking distance of the 25-percent ownership ceiling under the Electric Power Industry Reform Act (EPIRA).

The Energy Regulatory Commission (ERC) on Friday released Resolution No. 17, Series of 2026, setting this year's installed generating capacity and market share limitation for the Luzon, Visayas, and Mindanao grids, as well as the national grid.

Under EPIRA, no company or related entity may own, operate, or control more than 30 percent of the installed generating capacity in any power grid or 25 percent of the country's total installed generating capacity.

This year, the national installed generating capacity was pegged at 28.2 million kilowatts (kW), placing the maximum allowable national market share at about 7.05 million kW.

Against that threshold, the Aboitiz group accounted for 6.85 million kW, or 24.3 percent of national installed capacity. It also held the largest share in Luzon at 27.53 percent, alongside 16.99 percent in the Visayas and 14.85 percent in Mindanao.

San Miguel Corp. ranked second with a 19.62-percent national market share, followed by First Gen Corp. at 10.74 percent, Ayala Corp. at 6.91 percent, and Manila Electric Co. at 6.70 percent.

Despite the delayed release of the data, the ERC said it first conducted a more comprehensive review of shareholder agreements and ownership structures before finalizing the assessment.

The computation was based on the maximum stable load of all generation facilities as of 30 April.

"The annual determination of the Installed Generating Capacity and Market Share Limitation is a critical safeguard under EPIRA that prevents excessive concentration in electricity generation," ERC Chairperson and CEO Atty. Francis Saturnino C. Juan said.

"Healthy competition encourages greater investment, promotes innovation, and helps ensure that consumers benefit from more reliable, efficient, and competitively priced electricity. Through this exercise, the ERC continues to uphold a level playing field where no single market participant can unduly influence the generation sector to the detriment of consumers."

The ERC clarified that identifying dominant generation players does not, by itself, constitute a finding of any violation of the law.

Rather, the annual exercise serves as a regulatory monitoring mechanism to ensure compliance with EPIRA's ownership limits and enable the commission to act when necessary.

Under the rules, entities that exceed the prescribed market share must notify the ERC within 15 days from the start of the occurrence and explain the reasons for the non-compliance.