Gran Tierra Energy Inc. Announces Agreement to Sell its Colombia and Ecuador Business to Maurel & Prom and Reposition the Company for Fully Financed Growth

Gran Tierra Energy Inc. ( “Gran Tierra” or the “Company” ) (NYSE American:GTE) (TSX:GTE) (LSE:GTE) today announced that it has entered into a definitive share sale and purchase agreement (the “Agreement” ) to sell its oil business in Colombia and Ecuador (collectively, the “Divested Business” ) to Établissements Maurel & Prom S.A. ( “Maurel & Prom” or the “Purchaser” ), a Paris-listed international oil and natural gas exploration and production company majority owned by PT Pertamina Internasional Eksplorasi dan Produksi (“ PIEP ”), a subsidiary of Indonesia’s national energy company, PT Pertamina (Persero) ( “Pertamina” ), representing a total consideration of $1.33 billion (the “Transaction” ).

The Transaction values the Divested Business at a total enterprise value of $1.33 billion. This figure includes the assumption by the Purchaser of the Company’s 9.750% Senior Secured Amortizing Notes due 2031 (the “ 2031 Notes ”) and 9.500% Senior Notes due 2029 (the “ 2029 Notes ” and, together with the 2031 Notes, the “Assumed Notes” ), as well as the prepayment facility (the “Prepayment Agreement” ). After the assumption of substantially all liabilities, customary closing adjustments, working capital adjustments, redemption by the Company of its 7.750% Senior Notes due 2027 (the “ 2027 Notes ”), and transaction costs, the Company is expected to have total net cash proceeds of approximately $315 million (the “Net Cash Proceeds” ) of this total, the Company will have approximately $250 million in cash at closing, and the remaining $65 million will be payable 364 days thereafter pursuant to an unsecured note issued by the Divested Business.

The Divested Business comprises all of the Company’s assets in Colombia and Ecuador. The Transaction has been unanimously approved by Gran Tierra’s Board of Directors and is subject to the approval of Gran Tierra’s stockholders, the receipt of the requisite consents from certain creditors and the prepayment buyers under the Prepayment Agreement and customary regulatory approvals in Colombia and Ecuador, and the satisfaction of other closing conditions. Subject to satisfaction of these conditions, the Transaction is targeted to close on or about December 31, 2026, with an economic effective date of March 31, 2026.

The Divested Business represents approximately 29,000 barrels of oil per day of first half 2026 average working-interest production (before royalties), approximately 144 million barrels (MMbbl) of proved-plus-probable (2P) reserves (derived from the GTE McDaniel Reserves Report and before attributing reserves associated with the Tisquirama assets acquired in the first quarter of 2026), and approximately 1.4 million gross acres across Colombia and Ecuador. See “ Presentation of Oil and Gas Information ”.