CALGARY, ALBERTA--(Marketwired - July 1, 2016) - Gran Tierra Energy Inc. ("Gran Tierra" or the "Company") (NYSE MKT:GTE)(TSX:GTE) is pleased to announce that the Company has entered into an agreement (the "Acquisition Agreement") to acquire PetroLatina Energy Ltd. ("PetroLatina") for cash consideration of $525 million (the "Acquisition"), consisting of an initial payment of $500 million at closing, subject to closing adjustments, and a deferred payment of $25 million prior to December 31, 2016. PetroLatina is a private, independent exploration and production company with assets primarily in the Middle Magdalena basin of Colombia.

"The Acquisition represents a unique material opportunity in Colombia in terms of scale and upside potential, and will add a new core area for Gran Tierra in the prolific Middle Magdalena Basin," commented Gary Guidry, Gran Tierra's President and CEO, "The combination of Gran Tierra's strong, positive cash-flowing asset base and PetroLatina's attractive portfolio of development opportunities will create a premier Colombia-focused exploration and production company."

The Acquisition is expected to be funded through a combination of Gran Tierra's current cash balance, available borrowings under Gran Tierra's existing credit facilities, a new $130 million debt facility, and a private placement of up to $173.5 million of subscription receipts ("Subscription Receipts") priced at $3.00 per Subscription Receipt entitling each holder thereof to one share of common stock in the capital of the Corporation ("Common Shares"). The pricing reflects a 7.9 percent discount from the five day volume weighted average price of $3.26.

"Our balance sheet and financial strength along with low cost operations allow us to execute on our growth strategy in a low oil price environment," said Guidry. "We are acquiring significant proved, probable and possible reserves in a new core area in the Middle Magdalena basin which we expect to enhance our long-term growth strategy and to be an excellent fit with Gran Tierra's current reserves and resources base in the Putumayo basin."

Below are certain transaction highlights relating to the Acquisition.

Key Transaction Highlights⁽¹⁾

• Growth platform in Middle Magdalena basin with significant proved plus probable ("2P") reserves additions of 53 million barrels ("MMbbl") (100% oil), increasing Gran Tierra's pro forma December 31, 2015 2P reserves by 70% to 129 million barrels of oil equivalent ("MMBOE")⁽⁷⁾
• Complementary acreage positions in Middle Magdalena basin, Llanos basin and Putumayo basin; addition of 469 thousand working interest ("WI") acres across Colombian portfolio
• Expected PetroLatina H2/2016 WI before royalties 2P average daily production of 5,400 barrels of oil per day ("bopd")
• Expected PetroLatina 2018 WI before royalties 2P average daily production of 14,800 bopd
• Long term free cash flow generation and attractive pro forma operating netbacks⁽²⁾ of approximately $30 per barrel ("bbl")
• Pro forma Gran Tierra will have a diversified portfolio of three large producing oil fields and a diversified exploration portfolio of 694 MMBOE⁽⁵⁾ of unrisked mean prospective resources.
• Accretive on a per share basis to Gran Tierra's production, reserves and net asset value
• Expected cost savings from operational synergies and efficiencies
• Combined company work program is expected to be self-funding for at least the next five years.

Key Attributes of PetroLatina⁽¹⁾

PetroLatina's core asset is a 100% operated WI in the Midas Block located in the Middle Magdalena basin, which contains the Acordionero conventional oil field which PetroLatina discovered in 2013.

The Acquisition further enhances Gran Tierra's dominant land position in the Putumayo basin (addition of 79,069 WI acres) by increasing the Company's WI in the PUT-4 Block from 70% to 100% WI and adding the 100% WI PUT-25 block. The PUT-4 block has 7 prospects and consolidates an incremental 5 MMBOE⁽⁶⁾ of mean risked prospective resources. Gran Tierra is planning to drill the Siriri prospect on PUT-4 in 2016, which will test the N-Sands exploration play.

The Llanos blocks (addition of 310, 940 WI acres), LLA-1, LLA-53 and LLA-70, further diversify Gran Tierra's position in the basin and provide additional, operated, exploration acreage which may include stratigraphic and structural prospectivity.

To view Figure 1: Gran Tierra Energy and PetroLatina's Land Position in Colombia, visit the following link: http://media3.marketwire.com/docs/1061339-F1.pdf

Summary of Transaction

PetroLatina operational figures as follows:

Acquisition metrics, based on the purchase price of $525 million, are expected to be as follows:

Acquisition Process

The Acquisition has been unanimously approved by the board of directors of Gran Tierra. The Acquisition Agreement was entered into among an indirect subsidiary of the Company, PetroLatina and three key shareholders of PetroLatina that hold more than 80% of the shares of PetroLatina. Under the terms of the Acquisition Agreement, it is a condition of closing that all of the remaining shares of PetroLatina are acquired pursuant to provisions of the Articles of Association of PetroLatina upon the closing of the Acquisition. The Acquisition is also subject to customary closing conditions, including, among other things, any required regulatory approval, and is expected to close prior to October 31, 2016.

Financing of the Transaction

Consideration for the Acquisition will consist of an initial payment of $500 million at closing, subject to closing adjustments, and a deferred payment of $25 million prior to December 31, 2016. The Acquisition will be funded through a combination of Gran Tierra's cash and current restricted cash balance of $170 million⁽⁸⁾, concurrent private placement of up to $173.5 million of Subscription Receipts, a new $130 million debt facility, and Gran Tierra's existing credit facilities. Pro forma for the Acquisition and the financings, the Company had $123.5 million of available borrowings as of March 31, 2016.

In connection with the Acquisition, Gran Tierra has agreed to issue up to 57,835,134 Subscription Receipts priced at $3.00 per Subscription Receipt to certain institutional investors and certain directors and executive officers of Gran Tierra for aggregate gross proceeds of up to $173.5 million. Scotiabank, RBC Capital Markets and Dundee Securities Inc. served as placement agents (the "Agents") for the Subscription Receipt financing. Each Subscription Receipt will entitle the holder thereof to receive one Common Share upon satisfaction of certain conditions.

The proceeds from the sale of Subscription Receipts (less 50% of the placement agents' fees, the "Escrowed Funds"), will be held in escrow and will be released to Gran Tierra when (i) other than the payment of the purchase price, all conditions precedent to the completion of the Acquisition pursuant to the Acquisition Agreement, as may be amended from time to time, have been satisfied in accordance with the terms of the Acquisition Agreement or waived (provided no such amendment or waiver is materially adverse to the holders of the Subscription Receipts) and (ii) the parties to the Acquisition Agreement are ready, willing and able to consummate the transactions contemplated thereby concurrent with the release of the Escrowed Funds (the "Escrow Release Condition"). In the event the Escrow Release Condition is not satisfied prior to 5:00 p.m. (Toronto time) on October 31, 2016, the Acquisition Agreement is terminated in accordance with its terms, or we have announced that we do not intend to proceed with the Acquisition, each holder of Subscription Receipts will be entitled to its pro rata share of the Escrowed Funds, interest earned on Escrowed Funds, net of any applicable withholding taxes, and 50% of the placement agents' fees.

The offer and sale of the Subscription Receipts was conducted by way of a private placement in reliance on Section 4(a)(2) of the U.S. Securities Act of 1933, as amended, and in Canada by way of private placement in all provinces of Canada under applicable accredited investor and director and officer private placement exemptions. This press release does not constitute an offer to sell or the solicitation of an offer to buy the securities herein described, and shall not constitute an offer, solicitation or sale in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of that jurisdiction. The private placement of Subscription Receipts is expected to close on or about July 8, 2016.

Gran Tierra has entered into a commitment letter with Scotiabank, its lead lender, to provide up to $130 million in bridge financing to fund a portion of the Acquisition. The bridge facility is expected to have a tenor of 364 days, bear interest at USD LIBOR plus 6%, and would have customary bridge facility repayment terms allowing for multiple longer term financing options.

Updated Guidance

Gran Tierra expects to provide additional updated 2016 guidance for funds flow from operations and operating netback with the release of its second quarter 2016 results on or around August 8, 2016.

Advisors

Scotia Waterous acted as lead financial advisor and RBC Capital Markets also served as a financial advisor to Gran Tierra in connection with the Acquisition. Scotiabank, RBC Capital Markets and Dundee Securities acted as Joint Lead Agents to Gran Tierra in connection with the private placement. Scotiabank provided bank financing in connection with the Acquisition.

About Gran Tierra Energy Inc.

Gran Tierra Energy Inc. together with its subsidiaries is an independent international energy company focused on oil and natural gas exploration and production in Colombia. The Company also has business activities in Peru and Brazil.

Gran Tierra's Securities and Exchange Commission filings are available on a web site maintained by the Securities and Exchange Commission at http://www.sec.gov and on SEDAR at http://www.sedar.com.

Disclaimer

General Advisory

The information contained in this press release does not purport to be all-inclusive or contain all information that readers may require. You are encouraged to conduct your own analysis and review of Gran Tierra and of the information contained in this press release. Without limitation, you should read the entire record of publicly filed documents relating to the Company, consider the advice of your financial, legal, accounting, tax and other professional advisors and such other factors you consider appropriate in investigating and analyzing Gran Tierra. You should rely only on the information provided by Gran Tierra and are not entitled to rely on parts of that information to the exclusion of others. Gran Tierra has not authorized anyone to provide you with additional or different information, and any such information, including statements in media articles about Gran Tierra, should not be relied upon.

An investment in the securities of Gran Tierra is speculative and involves a high degree of risk. Gran Tierra's business is subject to the risks normally encountered in the oil and gas industry and certain other risks that are associated with Gran Tierra's current stage of development. An investment in the Company's securities is suitable only for those purchasers who are willing to risk a loss of some or all of their investment and who can afford to lose some or all of their investment. You should carefully consider the risks described under the heading "Risk Factors" in the Company's Annual Report on Form 10-K for the year ended December 31, 2015 and in the Company's subsequent SEC filings. Of particular significance, there is no certainty that the Acquisition will be completed.

Forward-Looking Information Advisory

This press release contains forward-looking statements within the meaning of the United States Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and financial outlook and forward looking information within the meaning of applicable Canadian securities laws (collectively, "forward-looking statements"). Such forward-looking statements include, but are not limited to, our ability to successfully complete the Acquisition, integrate the acquired assets with our own and realize the anticipated benefits, the scale, growth, diversity opportunities, planned synergies, expected production of Gran Tierra following completion of the Acquisition, the combined work program and operations going forward. Statements respecting reserves are forward-looking statements as they involve the implied assessment, based on estimates and assumptions, that the reserves described exist in the quantities predicted or estimated and can be profitably produced in the future.

Estimates of future production may be considered to be future-oriented financial information or a financial outlook for the purposes of applicable Canadian securities laws. Financial outlook and future-oriented financial information contained in this press release about prospective financial performance, financial position or cash flows are based on assumptions about future events, including economic conditions and proposed courses of action, based on management's assessment of the relevant information currently available, and to become available in the future. In particular, this press release contains projected operational information. These projections contain forward-looking statements and are based on a number of material assumptions and factors set out above. Actual results may differ significantly from the projections presented herein. These projections may also be considered to contain future-oriented financial information or a financial outlook. The actual results of Gran Tierra's operations for any period will likely vary from the amounts set forth in these projections, and such variations may be material. See above for a discussion of the risks that could cause actual results to vary. The future-oriented financial information and financial outlooks contained in this presentation have been approved by management as of the date of this presentation. Readers are cautioned that any such financial outlook and future-oriented financial information contained herein should not be used for purposes other than those for which it is disclosed herein. Gran Tierra and its management believe that the prospective financial information has been prepared on a reasonable basis, reflecting management's best estimates and judgments, and represent, to the best of management's knowledge and opinion, Gran Tierra's expected course of action. However, because this information is highly subjective, it should not be relied on as necessarily indicative of future results.

The forward-looking statements contained in this press release are based on certain assumptions made by Gran Tierra based on management's experience and perception of historical trends, current conditions, anticipated future development and other factors believed to be appropriate. Such statements are subject to a number of assumptions, risks and uncertainties, many of which are beyond Gran Tierra's control, which may cause actual results to differ materially from those implied or expressed by the forward-looking statements. These include the factors discussed or referenced under the heading "Part 1. Item 1A. Risk Factors" in Gran Tierra's 2015 Annual Report on Form 10-K, under the heading "Part II. Item 1A. Risk Factors" in Gran Tierra's Quarterly Reports on Form 10-Q and in the other reports and filings with the Securities and Exchange Commission.

All forward-looking statements speak only as of the date on which such statements are made, and Gran Tierra undertakes no obligation to correct or update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law. Gran Tierra's forward-looking statements are expressly qualified in their entirety by this cautionary statement.

Presentation of Oil and Gas Information

BOEs have been converted on the basis of six thousand cubic feet ("Mcf") natural gas to 1 barrel of oil. BOEs may be misleading, particularly if used in isolation. A BOE conversion ratio of 6 Mcf: 1 bbl is based on an energy equivalency conversion method primarily applicable at the burner tip and does not represent a value equivalency at the wellhead. In addition, given that the value ratio based on the current price of oil as compared with natural gas is significantly different from the energy equivalent of six to one, utilizing a BOE conversion ratio of 6 Mcf: 1 bbl would be misleading as an indication of value.

Estimates of reserves and future net revenue for individual properties may not reflect the same level of confidence as estimates of reserves and future net revenue for all properties, due to the effect of aggregation.

Proved reserves are those reserves that can be estimated with a high degree of certainty to be recoverable. It is likely that the actual remaining quantities recovered will exceed the estimated proved reserves.

Probable reserves are those additional reserves that are less certain to be recovered than proved reserves. It is equally likely that the actual remaining quantities recovered will be greater or less than the sum of the estimated proved plus probable reserves.

Possible reserves are those additional reserves that are less certain to be recovered than Probable reserves. There is a 10% probability that the quantities actually recovered will equal or exceed the sum of Proved plus Probable plus Possible reserves.
Estimates of Gran Tierra's and PetroLatina's reserves and the net present value of future net revenue attributable to the Gran Tierra's and PetroLatina's reserves, are based upon the GTE McDaniel Reserves Report and the PetroLatina McDaniel Reserves Report. The estimates of reserves provided in this presentation are estimates only and there is no guarantee that the estimated reserves will be recovered. Actual reserves may be greater than or less than the estimates provided in this in this presentation and the differences may be material. Estimates of net present value of future net revenue attributable to the disclosed reserves do not represent fair market value and there is uncertainty that the net present value of future net revenue will be realized. There is no assurance that the forecast price and cost assumptions applied by McDaniel in evaluating the disclosed reserves will be attained and variances could be material.

Prospective Resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from undiscovered accumulations by application of future development projects. Prospective resources have both an associated chance of discovery and a chance of development. Not all exploration projects will result in discoveries. The chance that an exploration project will result in the discovery of petroleum is referred to as the "chance of discovery." Thus, for an undiscovered accumulation the chance of commerciality is the product of two risk components-the chance of discovery and the chance of development. There is no certainty that any portion of the prospective resources will be discovered. If discovered, there is no certainty that it will be commercially viable to produce any portion of the prospective resources.

The estimates of prospective resources provided in this press release are estimates only and there is no guarantee that the estimated prospective resources will be recovered. Actual prospective resources may be greater than or less than the estimates provided in this in this press release and the differences may be material. There is no assurance that the forecast price and cost assumptions applied by McDaniel or a member of management who is a qualified reserves evaluator in evaluating the prospective resources will be attained and variances could be material. There is no certainty that any portion of the prospective resources will be discovered. If discovered, there is no certainty that it will be commercially viable to produce any portion of the prospective resources.

Estimates of prospective resources are by their nature more speculative than estimates of proved reserves and would require substantial capital spending over a significant number of years to implement recovery. Actual locations drilled and quantities that may be ultimately recovered from our properties will differ substantially. In addition, we have made no commitment to drill, and likely will not drill, all of the drilling locations that have been attributable to these quantities. Product types reasonably expected from the prospective resources are light and medium crude oil and conventional natural gas.

Except as otherwise set forth herein, the prospective resources estimates that are referred to herein are un-risked as to both chance of discovery and chance of development. Risks that could impact the chance of discovery and chance of development include, without limitation: geological uncertainty and uncertainty regarding individual well drainage areas; uncertainty regarding the consistency of productivity that may be achieved from lands with attributed resources; potential delays in development due to product prices, access to capital, availability of markets and/or take-away capacity; and uncertainty regarding potential flow rates from wells and the economics of those wells.

The following classification of prospective resources is used in the presentation:

In general, the significant factors that may change the prospective resources estimates include further delineation drilling, which could change the estimates either positively or negatively, future technology improvements, which would positively affect the estimates, and additional processing capacity that could affect the volumes recoverable or type of production. Additional facility design work, development plans, reservoir studies and delineation drilling is expected to be completed by the Company in accordance with its long-term resource development plan.

Readers should refer to the prospective resources disclosure under the heading 'Disclosure of Oil and Gas information' in Gran Tierra's press release dated January 21, 2016, for additional information.

Also, as non-GAAP measures:

Gran Tierra's before tax net present values of 2P reserves prepared in accordance with NI 51-101 and COGEH and discounted at 10% ("PV-10") differs from its standardized measure under generally accepted accounting principles in the United States ("U.S. GAAP") because (i) the U.S. Securities and Exchange Commission ("SEC") and the U.S. Financial Accounting Standards Board ("FASB") standards require that the standardized measure reflects reserves and related future net revenue estimated using average prices for the previous 12 months, whereas NI 51-101 reserves and related future net revenue are estimated based on forecast prices and costs and (ii) the standardized measure reflects discounted future income taxes related to Gran Tierra's operations. Gran Tierra believes that the presentation of PV-10 is useful to investors because it presents (i) relative monetary significance of its oil and natural gas properties regardless of tax structure and (ii) relative size and value of its reserves to other companies. Gran Tierra also uses this measure when assessing the potential return on investment related to its oil and natural gas properties. PV-10 and the standardized measure of discounted future net cash flows do not purport to present the fair value of Gran Tierra's oil and gas reserves. Gran Tierra has not provided a reconciliation of PV-10 to the standardized measure of discounted future net cash flows because it is impracticable to do so.

Disclosure of Reserve Information and Cautionary Note to U.S. Investors

Unless expressly stated otherwise, all estimates of proved, probable and possible reserves and related future net revenue disclosed in this presentation have been prepared in accordance with NI 51-101. Estimates of reserves and future net revenue made in accordance with NI 51-101 will differ from corresponding estimates prepared in accordance with SEC rules and disclosure requirements of FASB, and those differences may be material. NI 51-101, for example, requires disclosure of reserves and related future net revenue estimates based on forecast prices and costs, whereas SEC and FASB standards require that reserves and related future net revenue be estimated using average prices for the previous 12 months. In addition, NI 51-101 permits the presentation of reserves estimates on a "company gross" basis, representing Gran Tierra's working interest share before deduction of royalties, whereas SEC and FASB standards require the presentation of net reserve estimates after the deduction of royalties and similar payments. There are also differences in the technical reserves estimation standards applicable under NI 51-101 and, pursuant thereto, the COGEH, and those applicable under SEC and FASB requirements.

In addition to being a reporting issuer in certain Canadian jurisdictions, Gran Tierra is a registrant with the SEC and subject to domestic issuer reporting requirements under U.S. federal securities law, including with respect to the disclosure of reserves and other oil and gas information in accordance with U.S. federal securities law and applicable SEC rules and regulations (collectively, "SEC requirements"). Disclosure of such information in accordance with SEC requirements is included in the Company's Annual Report on Form 10-K and in other reports and materials filed with or furnished to the SEC and, as applicable, Canadian securities regulatory authorities. The SEC permits oil and gas companies that are subject to domestic issuer reporting requirements under U.S. federal securities law, in their filings with the SEC, to disclose only estimated proved, probable and possible reserves that meet the SEC's definitions of such terms. Gran Tierra has disclosed estimated proved, probable and possible reserves in its filings with the SEC. In addition, Gran Tierra prepares its financial statements in accordance with United States generally accepted accounting principles, which require that the notes to its annual financial statements include supplementary disclosure in respect of the Company's oil and gas activities, including estimates of its proved oil and gas reserves and a standardized measure of discounted future net cash flows relating to proved oil and gas reserve quantities. This supplementary financial statement disclosure is presented in accordance with FASB requirements, which align with corresponding SEC requirements concerning reserves estimation and reporting.

Investors are urged to consider closely the disclosures and risk factors in the Company's Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and in the other reports and filings with the SEC, available from the Company's offices or website. These forms can also be obtained from the SEC via the internet at www.sec.gov or by calling 1-800-SEC-0330.