Material Fact. Approval of RIGI Projects (Form 6-K)

City of Buenos Aires, October 6, 2026.

E-NOTA-20261113-64135

Messrs.

Comisión Nacional de Valores (Argentine Securities and Exchange Commission)

Bolsas y Mercados Argentinos S.A. (Argentine Stock Exchanges and Markets)

Bolsa de Comercio de Buenos Aires (Buenos Aires Stock Exchange)

Gerencia Técnica y de Valores Negociables (Technical and Negotiable Securities Management)

A3 Mercados S.A. (A3 Markets)

Re: Material Fact. Approval of RIGI Projects

Dear Sirs,

I am writing to you in my capacity as Head of Market Relations of Transportadora de Gas del Sur S.A. ("tgs" or the "Company"), in compliance with the regulations of the Argentine Securities and Exchange Commission and the applicable rules of the Buenos Aires Stock Exchange and A3 Markets.

We hereby inform you that, on November 12, 2026, pursuant to Resolutions No. 1976/2026 and No. 1977/2026 issued by the Argentine Ministry of Economy and published in the Official Gazette of the Argentine Republic on the date hereof, the applications submitted by Midstream de Gas del Sur S.A. ("MGS") and Procesadora de Gas del Sur S.A. ("PGS") for admission to the Large Investment Incentive Regime (Régimen de Incentivo para Grandes Inversiones - "RIGI") were approved.

Said companies were incorporated by tgs for the purpose of participating in the RIGI and developing the NGLs Project, which was previously disclosed to the market in a material fact notice dated June 10, 2026. In both cases, admission to the RIGI is effective as of October 14, 2026.

Yours sincerely.

Hernán Diego Flores Gómez

Head of Market Relations