FDI is limited to 40% in electricity transmission and distribution; no foreign shareholding restriction applies to electricity commercialisaiton (supply to contestable market) nor to power generation.
On 9 April 2022, Act RA 11659 amending the Public Service Act entered into force. The Act limited the scope of 'public utility' services subject to the 40% foreign ownership limitation under the Constitution, but it did not alter the treatment for the following activities: (a) distribution and transmission of electricity; (b) petroleum and petroleum products pipeline transmission systems; (c) water pipeline distribution systems; (d) wastewater and sewerage pipeline systems; (e) seaports; and (f) public utility vehicles. These activities continue to be considered 'public utilities' and thus remain subject to the above-mentioned restrictions. Other activities that were previously considered as public utilities, such as surface transportation companies (excluding road transportation activities (i.e.  public utility vehicles') that continue to be considered 'public utilities'), are no longer considered  'public utilities' and thus are no longer subject to such restrictions. 
"Only the investment areas and/or activities listed in the attached Eleventh Regular Foreign Investment Negative List shall be reserved for Philippine nationals, subject to the exceptions and conditions indicated therein.
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LIST A: FOREIGN OWNERSHIP IS LIMITED BY MANDATE OF THE CONSTITUTION AND SPECIFIC LAWS [...]
Up to Forty Percent (40%) Foreign Equity
18. Operation of public utilities (Art. XII, Sec. 11 of the Constitution; Sec. 16 of C.A. No. 146; Sec. 2(a) of R.A. No. 7718),8 except power generation and the supply of electricity to the contestable market (Sec. 6 and Sec. 29, respectively, of R.A. No. 9136) and such other like businesses or services not covered by the definition of public utilities9 [8 The Participation of foreign investors in the governing body of any public utility enterprise shall be limited to their proportionate share in its capital, and all the executive and managing officers of such corporation or association must be citizens of the Philippines (Article XII, Section 11 of the Constitution); 9 A “public utility” is a business or service engaged in regularly supplying the public with some commodity or service of consequence such as electricity, gas, water, transportation, telephone or telegraph service (Supreme Court ruling in JG Summit Holdings v. Court of Appeals, et al., September 24, 2003).][...]" (Eleventh Regular Foreign Investment Negative List (Executive Order No. 65 / 2018))
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"ARTICLE XII - National Economy and Patrimony [...]
SECTION 11. No franchise, certificate, or any other form of authorization for the operation of a public utility shall be granted except to citizens of the Philippines or to corporations or associations organized under the laws of the Philippines at least sixty per centum of whose capital is owned by such citizens, nor shall such franchise, certificate, or authorization be exclusive in character or for a longer period than fifty years. Neither shall any such franchise or right be granted except under the condition that it shall be subject to amendment, alteration, or repeal by the Congress when the common good so requires. The State shall encourage equity participation in public utilities by the general public. The participation of foreign investors in the governing body of any public utility enterprise shall be limited to their proportionate share in its capital, and all the executive and managing officers of such corporation or association must be citizens of the Philippines." (Art XII, Section 11 1987 Constitution of the Republic of The Philippines)
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"Section 4. Definition of Terms. - [...]
(h) "Contestable Market" refers to the electricity end-users who have a choice of a supplier of electricity, as may be determined by the ERC in accordance with this Act;
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Section 6. Generation Sector. - Generation of electric power shall be competitive and open.
Upon the effectivity of this Act, any new generation company shall, before it operates, secure from the Energy Regulatory Commission a certificate of compliance pursuant to the standards set forth in this Act, as well as health, safety and environmental clearances from the appropriate government agencies under existing laws.
Any law to the contrary notwithstanding, power generation shall not be considered a public utility operation. For this purpose, any person or entity engaged or which shall engage in power generation and supply of electricity shall not be required to secure a local or national franchise.
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Section 29. Supply Sector. - The supply of electricity to the contestable market shall require a license from the ERC, except for distribution utilities and electric cooperatives with respect to their existing franchise areas.
For this purpose, the ERC shall promulgate rules and regulations prescribing the qualifications of electricity suppliers which shall include, among other requirements, a demonstration of their technical capability, financial capability, and creditworthiness: Provided, That the ERC shall have authority to require electricity suppliers to furnish a bond or other evidence of the ability of a supplier to withstand market disturbances or other events that may increase the cost of providing service.
Any law to the contrary notwithstanding, supply of electricity to the contestable market shall not be considered a public utility operation. For this purpose, any person or entity which shall engage in the supply of electricity to the contestable market shall not be required to secure a local or national franchise.[...]" (Sec. 6 and Sec. 29 of R.A. No. 9136)
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"Sec. 13. (a) The Commission shall have jurisdiction and supervision over all public services, including public utilities, [...] 
(d) Public Utility. — Public utility refers to a public service that operates, manages or controls for public use any ofthe following: (1) Distribution of Electricity; (2) Transmission of Electricity; (3) Petroleum and Petroleum Products Pipeline Transmission Systems; (4) Water Pipeline Distribution Systems and Wastewater Pipeline Systems, including sewerage pipeline systems; (5) Seaports; and (6) Public Utility Vehicles. [...] A public service which is not classified as a public utility under this Act shall be considered a business affected with public interest for purposes of Sections 17 and 18 of Article XII of the Constitution. [...]
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Sec. 16. Proceedings of the Commission, upon notice and hearing. - The Commission shall have the power, upon proper notice and hearing in accordance with the rules and provisions of this Act:
(a) To issue certificates authorizing the operation of public service within the Philippines whenever the Commission finds that the operation of the public service proposed and the authorization to do business will promote the public interest in a proper and suitable manner: Provided, That any certificate authorizing the operation, management or control of a pubhc service shall only be issued to corporations, partnerships, associations or joint stock companies that are constituted and organized under the laws ofthe Philippines. [...]" (Republic Act No. 11659, 21 March 2022, (consolidation of House Bill No. 78 and Senate Bill No. 2094))
Eleventh Regular Foreign Investment Negative List (Executive Order No. 65 / 2018)
Art XII, Section 11 1987 Constitution of the Republic of The Philippines
Sec. 6 and Sec. 29 of R.A. No. 9136
Republic Act No. 11659, 21 March 2022, (consolidation of House Bill No. 78 and Senate Bill No. 2094)
[<a href="https://www.officialgazette.gov.ph/downloads/2018/10oct/20181029-EO-65-RRD.pdf">List</a>],[<a href="http://www.officialgazette.gov.ph/constitutions/1987-constitution/">Constitution</a>],[<a href="https://lawphil.net/statutes/repacts/ra2001/ra_9136_2001.html">Act</a>],[<a href="https://legacy.senate.gov.ph/republic_acts/ra%2011659.pdf">Act</a>],[<a href="https://www.aseanbriefing.com/news/philippines-senate-passes-bill-allowing-100-percent-foreign-ownership-of-public-services/">Other</a>]