Exhibit 99.3

UNAUDITED PRO FORMA CONDENSED CONsolidAteD FINANCIAL INFORMATION

All amounts expressed in Thousands of U.S. Dollars, except share and per share amounts or otherwise noted

On October 31, 2024, Gran Tierra Energy Inc. (“Gran Tierra” or the “Company”) acquired all of the issued and outstanding common shares of i3 Energy plc (“i3 Energy”), through a court sanctioned scheme arrangement under Part 26 of the UK Companies Act 2006 (the “Acquisition”) for a total consideration of $204,478.

Gran Tierra will transfer the entire issued share capital of i3 Energy to its wholly owned, indirect subsidiary, Gran Tierra Energy International Holdings GmbH (“Gran Tierra EIH”). Gran Tierra EIH is the holding entity for Gran Tierra's Colombian assets.

Under the terms of the Acquisition, each i3 Energy shareholder received:

Pursuant to the scheme arrangement, a mix and match facility was available to i3 Energy shareholders which enabled them to elect to vary the proportions in which they receive cash and New Gran Tierra Shares. Elections have been made and are reflected in the figures above.

New Gran Tierra Shares

5,808,925 new shares of common stock with par value of USD$0.001 per share in Gran Tierra were issued on November 1, 2024. As a result, Gran Tierra has total issued share capital of 36,460,141 common shares as of November 1, 2024 and holds no common shares in treasury.

Deferred Shares

In addition to its ordinary share capital, i3 Energy had 5,000 Deferred Shares in issue subscribed to by two of i3 Energy’s then founding directors for an aggregate subscription price of $65. Gran Tierra purchased the Deferred Shares for an aggregate consideration of $65 (£50) pursuant to share purchase agreements.

Stock Option Settlement

As part of the Acquisition, Gran Tierra settled all of i3 Energy’s outstanding stock options by paying participants of i3 Energy’s share plans a cash settlement of $1,994 (net of the option exercise price).

Financing

On September 18, 2024, Gran Tierra completed an offering of an additional $150,000 aggregate principal amount of its 9.50% senior secured amortizing notes due 2029, the net proceeds of which were used to satisfy a portion of the $161,786 cash consideration paid as part of the Acquisition.

The Unaudited Pro Forma Condensed Consolidated Financial Information does not give effect to any cost savings, operating synergies or revenue synergies that may result from the Acquisition. Assumptions and estimates underlying the pro forma adjustments are described in the Unaudited Pro Forma Condensed Consolidated Financial Information. The pro forma adjustments represent management’s estimates based on information available as of the date of this document and are subject to change as additional information becomes available and analyses are performed.

The Unaudited Pro Forma Condensed Consolidated Financial Information contains estimated adjustments, based upon available information and certain assumptions that we believe are reasonable under the circumstances. The assumptions underlying the pro forma adjustments are described in greater detail in the Unaudited Pro Forma Condensed Consolidated Financial Information. In many cases, these assumptions were based on preliminary information and estimates. In many cases, these assumptions were based on preliminary information and estimates. As of the date of this document, Gran Tierra has not finalized the detailed valuation studies necessary to determine the required estimates of fair value of the assets acquired and liabilities assumed of i3 Energy; based on preliminary work, we would anticipate potential changes, if any to the fair values of the oil & gas assets and associated deferred tax liabilities. However, as indicated in Note 2, Note 3, and Note 4, Gran Tierra has made certain adjustments to i3 Energy’s historical assets and liabilities book values, and adjustments to reflect certain preliminary estimates of fair value necessary to prepare the Unaudited Pro Forma Condensed Consolidated Financial Information.

The Unaudited Pro Forma Condensed Consolidated Financial Information has been prepared to give effect to the following:

unaudited pro forma condensed CONSOLIDATED statement of operations

For the Nine Months Ended September 30, 2024

(Thousands of U.S. Dollars, except share and per share amounts)

unaudited pro forma condensed CONSOLIDATED statement of operations

For the Year Ended December 31, 2023

(Thousands of U.S. Dollars, except share and per share amounts)

unaudited pro forma condensed CONSOLIDATED balance sheet

As at September 30, 2024

(Thousands of U.S. Dollars)

Notes to Unaudited Pro Forma Condensed Consolidated Financial Information

(Thousands of U.S. dollars, except share and per share amounts, or unless otherwise indicated)

Note 1. Basis of Presentation

The unaudited pro forma condensed consolidated balance sheet as of September 30, 2024 and the unaudited pro forma condensed consolidated statements of operations for the year ended December 31, 2023 and for the nine months ended September 30, 2024 of Gran Tierra (together, “the Unaudited Pro Forma Condensed Consolidated Financial Information”) were prepared for illustrative purposes only in compliance with Article 11 of Regulation S-X of the United States Securities and Exchange Commission. All dollar amounts are presented in U.S. dollars unless otherwise specified.

The unaudited pro forma condensed consolidated statement of operations for the year ended December 31, 2023 and the nine months ended September 30, 2024 have been prepared as if the Acquisition had been consummated on January 1, 2023, the beginning of the earliest period presented. The unaudited pro forma condensed consolidated balance sheet was prepared as if the Acquisition had been consummated on September 30, 2024.

The Unaudited Pro Forma Condensed Consolidated Financial Information is prepared as a business combination using the acquisition method of accounting in accordance with Financial Accounting Standards Board Accounting Standards Codification (“ASC”) Topic 805, Business Combinations (“Topic 805”), using the fair value concepts defined in ASC Topic 820, Fair Value Measurements and Disclosures. Gran Tierra has been treated as the acquirer for financial reporting purposes. Under the acquisition method of accounting, the purchase consideration allocated to i3 Energy’s assets and liabilities for preparation of the Unaudited Pro Forma Condensed Consolidated Financial Information is based upon their estimated preliminary fair values assuming the Acquisition was completed as of October 31, 2024.

The Unaudited Pro Forma Condensed Consolidated Financial Information depicts the Acquisition of i3 Energy by Gran Tierra, including adjustments to align i3 Energy’s historical accounting policies under International Financial Reporting Standards as issued by the International Accounting Standards Board (“IFRS”) to Gran Tierra’s significant accounting policies under U.S. Generally Accepted Accounting Principles (U.S. GAAP), as further discussed below.

The Unaudited Pro Forma Condensed Consolidated Financial Information has been compiled using accounting policies consistent with those adopted by Gran Tierra in accordance with U.S. GAAP as described in the consolidated financial statements of Gran Tierra for the year ended December 31, 2023, but do not include all of the disclosures required by U.S. GAAP. The unaudited pro forma condensed consolidated balance sheet and the unaudited pro forma condensed consolidated statement of operations was derived from and should be read in conjunction with:

The Unaudited Pro Forma Condensed Consolidated Financial Information may differ from the final purchase accounting given that the purchase price allocation is preliminary and subject to finalization of customary closing adjustments and that the identification and measurement of assets acquired and liabilities assumed are preliminary and subject to change as detailed valuation studies are finalized. The final purchase accounting adjustments may be materially different from the audited pro forma adjustments; based on preliminary work, we would anticipate potential changes, if any to the fair values of the oil & gas assets and associated deferred tax liabilities Additionally, exchange rate have move each period, so the assumptions of when the transactions occur for the purposes of pro forma presentation also impacts the U.S. dollar values assigned. Since the Unaudited Pro Forma Condensed Consolidated Financial Information have been developed to retroactively show the effect of the Acquisition that has occurred on a later date (even though this was accomplished by following generally accepted practice and using reasonable assumptions), there are limitations inherent in the very nature of such pro forma data.

The Unaudited Pro Forma Condensed Consolidated Financial Information does not give effect to any anticipated synergies, operating efficiencies, tax savings or cost saving that may be associated with the transaction. The Unaudited Pro Forma Condensed Consolidated Financial Information are not necessarily indicative of the results of operations that would have occurred had the Acquisition occurred on the date indicated, nor are the unaudited pro forma condensed consolidated financial information indicative of the results of operation of future periods.

Purchase Consideration

The purchase consideration of $204,478 (see Note 4.) was based on the closing price of Gran Tierra’s common share on October 31, 2024 ($6.31 per share) and the cash consideration and dividend cash payment translated at a rate of USD:GBP of $0.78 as at October 31, 2024.

Note 2. i3 Energy - IFRS to U.S. GAAP Adjustments

Historical balances derived from i3 Energy’s audited consolidated financial statements and unaudited condensed interim consolidated financial statements as described above, are presented under IFRS and are in Pounds Sterling (£, GBP).

Condensed Consolidated Statement of Comprehensive Income of i3 Energy

For the nine months ended September 30, 2024

Consolidated Statement of Comprehensive Income of i3 Energy

For the Year Ended December 31, 2023

Consolidated Statement of Financial Position of i3 Energy

As at September 30, 2024

Gran Tierra reports its historical financial information in U.S dollars, while i3 Energy reports its historical financial information in pound sterling (GBP). For purposes of this presentation:

Adjustment reflects the following differences in the measurement of asset retirement obligations between IFRS and U.S. GAAP:

The US GAAP value of ARO was determined using credit adjusted risk-free rates which ranged from 5.41% to 11%. The change in discount rate and application of a layered approach results in a reduction to PP&E of £29,458, and a reduction of ARO of £32,861 as at September 30, 2024.

Additional accretion expense of £65 was recognized for the nine-month period ended September 30, 2024 (£188 for the year-ended December 30, 2023).

Under IFRS, i3 Energy’s producing wells are depleted on a units-of-production basis based on proved and probable reserves. The adjustment reflects depletion calculated based on the revised PP&E values and on a units-of-production basis based on proved reserves, in accordance with U.S. GAAP.

Proved oil and gas assets net carrying amount was reduced by £29,943 as at September 30, 2024. Depletion expense decreased by £1,510 and increased by £772, respectively, for the nine months ended September 30, 2024 and year ended December 31, 2023. Refer to Note D for the details of impairment in 2020 as a result of the ceiling test completed on proved oil and gas assets.

Gran Tierra accounts for exploration and development activities under the full cost method of accounting under US GAAP. Entities who use the full cost method must conduct an annual full cost ceiling impairment test on its proved oil and gas assets using the 12-month unweighted arithmetic average of the first-day-of-the-month pricing. As a part of the conversion i3 Energy completed ceiling test for its proved oil and gas assets on an annual basis from the date at which it had depletable assets (the year ended 2020). As a result, as at December 31, 2020 there was an impairment charge of $43,443 which impacts the net book value of proved oil and gas properties as at December 31, 2020 subsequent years and the subsequent depletion expense under US GAAP. Under U.S. GAAP there is no reversal of impairment. Under IFRS, i3 Energy did not record any impairment (as under IFRS, future pricing may be used), this results in higher PP&E balances and larger DD&A under IFRS.

Under IFRS, i3 Energy recognized compensation expense on its graded vesting awards (stock options) as if each tranche was a separate share-based payment arrangement. Under U.S. GAAP, Gran Tierra’s accounting policy is to account for awards with graded vesting, ratably over the longest vesting tranche. As a result, an additional charge of £700 and £520, was recorded to administrative expenses for the year-ended December 31, 2023 and nine-months ended September 30, 2024, respectively.

Gran Tierra has performed a preliminary assessment of the potential U.S. GAAP differences for exploration and evaluation expenditures, inventory, and lessee leases, and have determined these differences are not material. As such, these adjustments have not been reflected in the unaudited pro forma financial information.

The deferred income tax asset, and liability have been adjusted to account for different U.S. GAAP book values as a result of the adjustments above, creating a different taxable temporary difference.

Tax expense was adjusted for the nine-month period ended September 30, 2024, and year-ended December 31, 2023 by applying i3 Energy’s statutory tax rate of 23% to tax effect the U.S. GAAP adjustments in the corresponding periods.

Note 3. i3 Energy’s Historical Financial Statements

The historical balances reflect certain reclassifications of i3 Energy’s consolidated statements of comprehensive income and consolidated statement of financial position categories to conform to Gran Tierra’s presentation in its consolidated statement of operations and consolidated balance sheets. Further review may identify additional reclassifications that could have a material impact on the unaudited pro forma financial information of the Company.

Note 4. Purchase Consideration and Preliminary Purchase Allocation Adjustments

The acquisition of all of the issued and outstanding common shares of i3 Energy is accounted for as a business combination under ASC 805 – Business Combinations.

The aggregate consideration for the acquisition of the i3 Energy was estimated to be $204,478. The consideration was comprised of:

Under the i3 Energy share option plan, i3 Energy had 48,463,468 options outstanding, immediately prior to the Acquisition. In accordance with the i3 Energy share option plan, these options will immediately vest upon a change in control event. The consideration for i3 Energy stock options, a total sum of $1,994, was calculated based on:

A total value of 13.92 pence per share, which resulted in 43,263,465 options in the money. The cash consideration for i3 Energy’s stock option was based on 13.92 pence per share less the option exercise price per share.

Under the acquisition method of accounting, the identifiable assets acquired and liabilities assumed are recorded at their acquisition date fair values. Gran Tierra is currently assessing the identification and measurement of the assets acquired and liabilities assumed as of the date of the Acquisition. As the values of certain of these assets and liabilities are preliminary in nature, they are subject to adjustment as additional information is obtained about the facts and circumstances that existed as of the acquisition date. The preliminary purchase price allocation below is based on estimates of the fair value as of October 31, 2024. Gran Tierra has made certain adjustments to the historical book values of the assets and liabilities of i3 Energy to reflect preliminary estimates of fair value necessary to prepare the Unaudited Pro Forma Condensed Consolidated Financial Information. Upon final completion of the fair value assessment, the ultimate purchase price allocation may materially differ from the preliminary assessment outlined below.

The table below summarizes the preliminary allocation of the purchase price to the assets acquired and liabilities assumed for the purposes of the unaudited pro forma financial information as if the transaction occurred on September 30, 2024:

The following steps are required to complete the purchase price allocation and are expected to be completed during 2025:

The fair value of the assumed accounts receivable, which represents the estimated worth of these receivables in an open market transaction, is approximately equal to their net book value.

The fair value of proved oil and gas assets is $262,046, and the fair value of unproved oil and gas assets is $7,684 based on Gran Tierra’s preliminary assessment. As stated above, this represents management’s preliminary estimates of the fair value of i3 Energy’s assets and liabilities acquired. Management is still undertaking the final valuation and this may be materially different than included in the pro forma financial information.

The fair value of unproved oil and gas assets of $7,684 is attributable to i3 Energy’s Canadian unproved oil and gas assets. The fair value of i3 Energy’s UK unproved oil and gas assets was determined to be $nil, as i3 Energy’s application for the P.2358 license related to the Serenity license has been extended. Serenity as a stand-alone is viewed as uneconomical to further develop. i3 Energy continues to explore whether Serenity in conjunction with surrounding areas may be viable, however there is no guarantee that i3 Energy could obtain necessary licenses.

As at September 30, 2024, i3 Energy had 48,463,468 share options outstanding. As part of the Acquisition, on behalf of Gran Tierra, i3 Energy paid stock option holders cash consideration of $1,994 to settle the outstanding stock options, net of the option excise price. Based on the cash settlement per stock option of 13.91 pence, 43,263,468 options were in the money.

Note 5. Assumptions and Adjustments to Unaudited Pro Forma Financial Information

Adjustments to Unaudited Pro Forma Condensed Consolidated Balance Sheet

The unaudited pro forma condensed consolidated balance sheet of Gran Tierra as of September 30, 2024 has been adjusted to reflect the following transactions as if the Acquisition date had occurred as of September 30, 2024:

Note 6. Assumptions and Adjustments to Unaudited Pro Forma Financial Information

Adjustments to Unaudited Pro Forma Condensed Consolidated Statement of Operations for the nine months ended September 30, 2024

The unaudited pro forma condensed consolidated statement of operations of Gran Tierra for the nine months ended September 30, 2024 have been adjusted to reflect the following transactions as if the Acquisition had occurred on January 1, 2023:

Note 7. Assumptions and Adjustments to Unaudited Pro Forma Financial Information

Adjustments to Unaudited Pro Forma Condensed Consolidated Statement of Operations for the year ended December 31, 2023

The unaudited pro forma condensed consolidated statement of operations of Gran Tierra for the year ended December 31, 2023 have been adjusted to reflect the following transactions as if the Acquisition had occurred on January 1, 2023:

On August 19, 2024, Gran Tierra entered into a credit facility agreement with a borrowing base of $107,000 (“Loan Facility”) in connection with the acquisition of i3 Energy. As at September 30, 2024, there was no outstanding balance under the Loan Facility and the Loan Facility was terminated on October 31, 2024, Gran Tierra did not incur interest on the Loan Facility. Additionally, on September 18, 2024, Gran Tierra issued $150,000 of 9.5% senior notes due October 2029 and received cash proceeds of $139,800. The net proceeds were used to pay a portion of the $167,824 cash consideration paid in the Acquisition. For the nine months ended September 30, 2024 and year ended December 31, 2023, if the Acquisition had occurred on January 1, 2023, the interest expense would be $10,688 and $14,250, respectively. The incremental interest expense has not been reflected in the unaudited pro forma financial information.

Note 8. Net Income (Loss) Per Share

The pro forma net earnings per share for the year ended December 31, 2023 and nine-months ended September 30, 2024 is as follows:

[1] Pro forma net income (loss) per share includes the related pro forma adjustments as referred to in section “Unaudited Pro Forma Condensed Consolidated Statement of Operations”.