Ratification of its Onshore Exploration, Development and Production Sharing Agreement in Azerbaijan

CALGARY, Alberta, Oct. 05, 2026 (GLOBE NEWSWIRE) -- Gran Tierra Energy Inc. (“Gran Tierra” or the “Company”) (NYSE American:GTE)(TSX:GTE)(LSE:GTE) is pleased to announce that the Milli Majlis, the Parliament of the Republic of Azerbaijan, has ratified the exploration, development and production sharing agreement (the “EDPSA”) for the onshore Guba-Khazaryani region (the “Contract Area”) that the Company signed with the State Oil Company of the Republic of Azerbaijan on February 18, 2026.

“We would like to thank our partner, the State Oil Company of the Republic of Azerbaijan, the Government of the Republic of Azerbaijan and all of its agencies involved in the ratification process, and the Milli Majlis for their hard work and commitment in passing this bill during the first plenary session of the autumn term,” said Gary Guidry, President and Chief Executive Officer of Gran Tierra.

Airborne dFTG Program Update

Gran Tierra has completed the flying of its airborne digital full tensor gradiometry (“dFTG”) survey in Azerbaijan. Gran Tierra flew 102 lines for 5,775-line kilometers, covering a total area of 4,815 square kilometers. The dFTG information will be used to help define the geometry of sedimentary basins and fault-related structures that potentially trap oil and gas in the Contract Area. This information will be integrated with existing seismic and exploratory well data to optimize the selection of future seismic acquisition areas and exploration and appraisal drilling locations.

About Gran Tierra Energy Inc.

Gran Tierra Energy Inc., together with its subsidiaries, is an independent international energy company currently focused on oil and natural gas exploration and production in Canada, Colombia and Ecuador. The Company is the operator of, and holds a 65% working interest in, an onshore exploration, development and production sharing agreement in Azerbaijan. Upon completion of the previously announced sale of its Colombian and Ecuadorian businesses (the “Sale”), the Company’s operations will be focused on Canada and Azerbaijan, and the Company will continue to pursue additional new growth opportunities that would further strengthen the Company’s portfolio. The Company’s common stock trades on the NYSE American, the Toronto Stock Exchange and the London Stock Exchange under the ticker symbol GTE. Additional information concerning Gran Tierra is available at www.grantierra.com. Except to the extent expressly stated otherwise, information on the Company’s website or accessible from our website or any other website is not incorporated by reference into and should not be considered part of this press release. Investor inquiries may be directed to info@grantierra.com or (403) 265-3221.

Additional Information and Where to Find It

This press release may be deemed to be solicitation material in respect of the Sale. In connection with the Sale, the Company filed a definitive proxy statement on Schedule 14A (the “Proxy Statement”) with the SEC on September 23, 2026, for the special meeting of stockholders to be held on October 9, 2026 (the “Special Meeting”). This press release is not a substitute for the Proxy Statement or any other document the Company may file with the SEC in connection with the Sale. Stockholders are urged to read the Proxy Statement and any other relevant documents filed with the SEC carefully and in their entirety because they contain important information about the Sale. Stockholders may obtain free copies of the Proxy Statement and other documents filed by the Company with the SEC at www.sec.gov and on the Company’s website at www.grantierra.com.

Participants in the Solicitation

The Company and its directors and executive officers may be deemed to be participants in the solicitation of proxies from the Company’s stockholders in respect of the Special Meeting. Information regarding the Company’s directors and executive officers and their interests in the Sale is contained in the Proxy Statement, which may be obtained free of charge from the sources indicated above.