Results of the Previously Announced Solicitation of Consents to Proposed Amendments to the Indenture Governing its Senior Secured Amortizing Notes due 2031

CALGARY, Alberta, Sept. 22, 2026 (GLOBE NEWSWIRE) -- Gran Tierra Energy Inc. (“Gran Tierra” or the “Company”) (NYSE American: GTE) (TSX:GTE) (LSE:GTE) today announced the results of its previously announced solicitation (the “Consent Solicitation”) of consents (the “Consents”) from Holders of its 9.750% Senior Secured Amortizing Notes due 2031 (the “Notes”) to effect certain proposed amendments (the “Proposed Amendments”) to the indenture dated as of February 18, 2026, under which the Notes were issued (the “Indenture”), pursuant to the terms and subject to the conditions set forth in the Consent Solicitation Statement, dated September 11, 2026 (the “Consent Solicitation Statement”). Any capitalized terms used in this press release without definition have the respective meanings assigned to such terms in the Consent Solicitation Statement.

As previously announced, the Consent Solicitation was conducted in connection with the previously announced sale of Gran Tierra’s Colombian and Ecuadorian businesses to Maurel & Prom for total consideration of approximately $1.33 billion, subject to adjustment (the “Sale”), pursuant to the terms and conditions of the Share Sale and Purchase Agreement entered into on August 5, 2026.

As of September 22, 2026 and according to the information received by D.F. King & Co. Inc., consents to the Proposed Amendments had been provided and not validly revoked by holders of not less than 50% in aggregate principal amount of the Notes outstanding. Accordingly, the Company has obtained the consents required to effect the Proposed Amendments.

On September 22, 2026, the Company, the Note Guarantors and the Trustee executed a supplemental indenture (the “Supplemental Indenture”) to effect the Proposed Amendments in accordance with the Consent Solicitation Statement, dated as of September 11, 2026. The Supplemental Indenture became effective immediately upon execution but will only become operative on the closing date of the Sale, at which time it will be binding on all holders of the Notes, including those who did not deliver a consent at or prior to such execution. The consent fee payable to Holders who validly delivered (and did not validly revoke) their consents prior to the Expiration Time will be payable on the closing date of the Sale.

BofA Securities, Inc. served as sole Solicitation Agent in the Consent Solicitation and D.F. King & Co. Inc. served as the Information and Tabulation Agent. Persons with questions regarding the Consent Solicitation should contact BofA Securities, Inc. at (toll free) (888) 292-0070 or (collect) (646) 855-8988. Requests for the Consent Solicitation Statement should be directed to D.F. King & Co. Inc., at (toll free) (888) 548-6498, (banks and brokers) (646) 582-9168 or by email to gte@dfking.com.

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, Ecuador and Azerbaijan. Upon completion of the Sale described in this press release, the Company’s producing operations will be focused on Canada, and the Company will continue to pursue its exploration interests in Azerbaijan and 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.