Exhibit 4.3



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|                                                             |             | 



|                                            | Section I - ESTF                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                       
|------------------------------------------- | ----------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Natural
        Gas Transportation Contract
|                                            | Firm Transportation Service                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                       
|1. Identification                           | Contract Number                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                       
|                                            | ESTF-029 -2008                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                       
|2. Transporter                              | 2.1Corporate Name                                                                                           | 2.2 Tax Identification                                                                                                                                                                                                                                                                                                                                                                                                
|                                            | Transportadora de Gas del Interior S.A. E.S.P.                                                              | 900.134.459-7                                                                                                                                                                                                                                                                                                                                                                                                         
|                                            | 2.3 Legal Representative                                                                                    | 2.4 Identification                                                                                                                                                                                                                                                                                                                                                                                                    
|                                            | JORGE ARMANDO PINEDA SÁNCHEZ                                                                                | 91.241.552 of Bucaramanga                                                                                                                                                                                                                                                                                                                                                                                             
|                                            |                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                       
|3. Shipper                                  | 3.1 Corporate Name                                                                                          | 3.2 Tax Identification                                                                                                                                                                                                                                                                                                                                                                                                
|                                            | ECOPETROL S.A.                                                                                              | 899.999.068-1                                                                                                                                                                                                                                                                                                                                                                                                         
|                                            | 3.3 Legal Representative                                                                                    | 3.4 Identification                                                                                                                                                                                                                                                                                                                                                                                                    
|                                            | CAMILO MARULANDA LÓPEZ                                                                                      | 10.008.868 of Pereira                                                                                                                                                                                                                                                                                                                                                                                                 
|4. Description                              | 4.1 Entry Hub                                                                                               | 1-
        4.2 Exit
        Hub                                                                                                                                                                                                                                                                                                                                                                                       
|                                            | Ballena                                                                                                     | Barrancabermeja                                                                                                                                                                                                                                                                                                                                                                                                       
|                                            | 4.3 Entry Point                                                                                             | 4.4 Exit Point                                                                                                                                                                                                                                                                                                                                                                                                        
|                                            | 1. Outlet flange of the meter located at the Centragas Ballena Station.                                     | 1.
        Outlet flange of the meters located in the 16" line in the COGB unless otherwise agreed by the Parties.
        
        2.
        Hot tap made on the 20" Gas line between Centragas and the COGB located on the property of Petrosantander that transports
        Gas to the gas turbine of the Barrancabermeja Refinery Department (GRB) owned by the Shipper, unless otherwise agreed by the Parties.
|                                            | 4.5 Diversion point:                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                       
|                                            | Inlet flange of the scraper trap at the Cuisiana CPF on the Cusiana – El Porvenir – La Belleza gas pipeline |                                                                                                                                                                                                                                                                                                                                                                                                                       



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|5. Dates and terms         | 5.1 Contract Date                                      | 5.2 Service Commencement Date                        
|-------------------------- | ------------------------------------------------------ | -----------------------------------------------------
|                           | October 1, 2008                                        | December 1, 2012                                     
|                           | 5.3 Completion Period                                  | 5.4 Trial Period                                     
|                           | Until December 31, 2020                                | None                                                 
|6. Capacity                | 6.1 Contracted Firm Capacity (kcf/d)                   |                                                      
|                           | From December 1, 2012 to December 31, 2012             | Point 1: 70,000                                      
|                           |                                                        | Point 2: 17,786                                      
|                           |                                                        | Total: 87,786                                        
|                           | From January 1, 2013 to December 31, 2020              | Point 1: 80,000                                      
|                           |                                                        | Point 2: 20,000                                      
|                           |                                                        | Total: 100,000                                       
|7. Fees and Contract Price | 7.1 Structure of Charges                               | 7.2 Fixed Charge (USD/kcf/d-year)                    
|                           | 100% F - 0% V                                          | 223,558                                              
|                           | 7.3 Variable Charge (USD/kfc)                          | 7.4 Fixed
        Charge for AO&M ($/kcf/d-year)     
|                           | 0                                                      | 398,349                                              
|                           | 7.5 Reference Capacity Charge
        (USD/kcf/d-year) | 7.6 Daily Reference Capacity
        Charge (USD/kcf)
|                           | 126                                                    | 0.345                                                
|                           | 7.6 Estimated Contract Price                           | USD                                                  
|                           | From December 1, 2012 to December 31, 2012             | 180,513,410                                          
|8. Addresses               | 8.1.1 Postal                                           | 8.1.2 Telephone                                      
|8.1 Transporter            | Carrera 34 No 41-51 
Bucaramanga                       | (7) 6320002                                          
|                           | 8.1.3 Fax                                              | 8.1.4 E-mail                                         
|                           | (7) 6320002 Ext 455                                    | sonia.sanabria@tgi.com.co                            
|8.2 Shipper                | 8.2.1 Postal                                           | 8.2.2 Telephone                                      
|                           | Carrera 13A No. 87-10                                  | (57)(1)234-4437                                      
|                           | 8.2.3 Fax                                              | 8.2.4 E-mail                                         
|                           | (1) 2344492                                            | ccg@ecopetrol.com.co                                 
|                           |                                                        |                                                      



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| | 8.2.5 Fax for billing | 
| | --------------------- | 
| | (1) 2344500           | 



|9. Nature of the Parties |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|9.1 The Shipper          | A decentralized national government agency, created by Statute 165 of 1948 with TIN899.999.068-1, organized as a Mixed Economy Corporation pursuant to Article 2 of Statute 1118 of 2006, related to the Ministry of Mines and Energy, with registered office in Bogotá D.C., all of whose bylaws are contained in Notarial instrument No. 5314 of December 14, 2007 and the modifications thereto, executed at the Office of Notary Public No. 2 of the Notarial Circuit of Bogotá D.C. and registered with the Chamber of Commerce of Bogotá D.C.
|                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|9.2 The Transporter      | A Corporate Provider of Public Services formed on February 16, 2007 by means of notarial instrument No. 67 executed at the office of notary public No. 11 of the notarial circuit of Bucaramanga, registered in the chamber of commerce, business register number 05-138524-04, subject to regulation, supervision, and control by the competent authorities, such as the Energy and Gas Regulation Commission (CREG), the Mining and Energy Planning Unit (UPME), and the Superintendency of Domestic Public Services (SSPD).                     



CHAPTER
I



GENERAL CONDITIONS



1.          IDENTIFICATION
OF THE PARTIES



The
signatories, to wit: 1)JORGE ARMANDO PINEDA SÁNCHEZ,
of legal age, identified as shown beneath the signature, acting as First Alternate of the President on behalf and as legal representative
ofTRANSPORTADORA DE GAS DEL INTERIOR S.A. E.S.P. a Corporate Provider of Public
Services formed on February 16, 2007 by means of notarial instrument No. 67 executed at the office of notary public No. 11 of the
Bucaramanga circuit, registered with the chamber of commerce on February 19, 2007 with business registration number 05-138524-O4
and TIN 900-134-459-7 and 2)CAMILO MARULANDA LÓPEZ, of legal age, identified with
citizenship card number 10.008.868, issued in Pereira, in his capacity as Vice President of Supply and Marketing of ECOPETROL S.A.,
who, in exercise of the authority contained in the Delegation Manual, is acting in the name, place, and stead of ECOPETROL, S.A.,
a decentralized national government agency, created by Statute 165 of 1948 with TIN899.999.068-1, organized as a
Mixed Economy Corporation pursuant to Article 2 of Statute 1118 of 2006, related to the Ministry of Mines and Energy, with registered
office in Bogotá D.C., all of whose bylaws are contained in Notarial instrument No. 5314 of December 14, 2007 and the modifications
thereto, executed at the Office of Notary Public No. 2 of the Notarial Circuit of Bogotá D.C. and registered with the Chamber of
Commerce of Bogotá D.C. (hereinafter THE SHIPPER) have entered into the following firm Natural Gas Transportation Contract,
contained in the following clauses.



2.          RECITALS



2.1.       Whereas
the TRANSPORTER owns and operates a system of gas pipelines within the country (System), which pass close to the SHIPPER’s
facilities.



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2.2.          Whereas
the Shipper on June 11, 2008 notified the TRANSPORTER of its interest in contracting firm transportation capacity from Ballena
to the exit point specified in number 4.4 of Section I ESTF, for which it requires, inter alia, the transportation of natural gas
through the Ballena – Barrancabermeja gas pipeline.



2.3.          Whereas
the TRANSPORTER does not currently have sufficient primary capacity available in the Ballena – Barrancabermeja gas pipeline
to meet the SHIPPER’s request and, therefore, as a result of the SHIPPER’s request for capacity, has decided to increase
the capacity of said gas pipeline.



2.4           Whereas
the SHIPPER agrees to enter into the Contract subject to the execution of the increase in capacity that the TRANSPORTER will make
in the Ballena – Barrancabermeja gas pipeline.



2.5           Whereas
the TRANSPORTER and the SHIPPER, on the basis of Article 5.5 of Resolution CREG-001-2000 have freely agreed upon the charges for
the remuneration of the natural gas transportation service in accordance with Resolution CREG 125 of 2003.



2.6           Whereas
in the schedule of transportation fees of this Contract the Parties have agreed to apply 100% of the stamp taxes for branch and
main pipelines.



2.7           Whereas
the SHIPPER has entered into or will enter into the agreements necessary to acquire the volumes of Gas for which it is contracting
the Service.



2.8           Whereas
the Parties recognize and accept that, because Gas Transportation is a complementary public service activity pursuant to Statute
142 of 1994, both this Contract and the transportation service are subject to State regulation, control, and supervision, which
may result in modifications to this Contract.



2.9           Whereas
the SHIPPER has already verified in the Bulletin of Fiscal Debtors prepared and published by the General Accounting Office that
the TRANSPORTER is not listed therein as a person who has been declared a tax debtor in a final and unappealable judgment.



2.10         Whereas
the TRANSPORTER establishes with a clearance certificate issued by its statutory auditor within the month prior to the date of
signature hereof, that it is not in arrears with its payments to the health, occupational hazards, and pensions systems, or with
its contributions to the Family Subsidy Funds, the Colombian Family Welfare Institute, and the National Apprenticeship Services
with regard to any of its employees.



2.11         Whereas
the representatives of both THE TRANSPORTER and THE SHIPPER are authorized to sign this Contract.



2.12         Whereas
neither the TRANSPORTER nor THE SHIPPER are legally disqualified from entering into this Contract.



2.13         Whereas
all the contents hereof and the Exhibits hereto form an integral part of this Contract.



2.14         Whereas
the TRANSPORTER’s Commercial Committee No. 9 recommended that TGI S.A. E.S.P. enter into this contract.

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3.DEFINITIONS



Whenever terms with an initial capital letter appear (in singular
or plural) in this Contract or in the Exhibits, clarification, or modifications hereto, they shall be considered definitions for
the purposes hereof and shall have the meanings set forth below, without prejudice to their definitions in the Law:



|Contract Year                           |  | One year of contractual performance. The first Contract Year shall commence on the Service Commencement Date and shall end twelve (12) months later.                                                                                                                                                                                                              
|--------------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Firm Capacity                           |  | Capacity that, in accordance with the contracts entered into, may not be interrupted by the Transporter, except in cases of emergency or force majeure.                                                                                                                                                                                                           
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Daily Reference Capacity Charge         |  | (Reference Capacity Charge) / 365 in USD/kcf                                                                                                                                                                                                                                                                                                                      
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Fixed Charge                            |  | Annual charge to pay for the investment costs applicable as from the Service Commencement Date to the Contracted Capacity expressed in US$/kcf/d-year                                                                                                                                                                                                             
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Reference Capacity Charge               |  | The Capacity Charge for the Barrancabermeja - La Dorada Section, applicable to the determination of sanctions payable by the SHIPPER or recognitions payable by the TRANSPORTER in US$/kcf/d-year. This charge is indicated in Section I.                                                                                                                         
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|AO&M Charge                             |  | Annual Fixed Charge to
    pay for the costs of Administration, Operation, and Maintenance. It is applied to the Contracted Capacity expressed in pesos
    ($)/kcf/d-year                                                                                                                                                                                        
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Variable Charge                         |  | Charge to pay for the investment cost. It is applied to the volume of Gas transported expressed in USD/kcf.                                                                                                                                                                                                                                                       
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Transportation Nomination Cycle         |  | Process that begins with the request for transportation services made by a Shipper to the Primary Control Center (CPC) concerning the Amount of Energy and the calorific value of the gas that it is going to deliver at the Entry Point and receive at the Exit Point of a Transportation System on a Gas Day and that ends with the Confirmation of the request.
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Gas Transportation Contract or Contract |  | The present Contract for the provision of thefirm Natural Gas Transportation Service. It includes the following Exhibits: (i) Exhibit I: Quality Specifications of the Natural Gas for Transportation. (ii) Exhibit II: Measurement. (iii) Exhibit III: Guarantee Amount                                                                                          
|                                        |  |                                                                                                                                                                                                                                                                                                                                                                   
|Primary Control Centers (CPC)           |  | Centers belonging to the different gas pipelines (Transportation Systems) that make up the National Transportation System. They are responsible for advancing the operational, commercial, and other processes defined in the Single Code on Natural Gas Transportation (RUT).                                                                                    





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|Balance Account              |  | The accumulated difference between the Amount of Energy Delivered and the Amount of Energy Taken by a Shipper during one month                                                                                                                                                                                                                        
|---------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Diversion                    |  | A change at the Entry and/or Exit Points affecting the initial or primary origin or destination specified in this Contract.                                                                                                                                                                                                                           
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Gas Day                      |  | Official day of the Republic of Colombia running from 00:00 hours until 24:00 hours, during which the Natural Gas Transportation Service is provided by the System in Firm Capacity mode in exchange for payment of the appropriate fee.                                                                                                              
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Service Commencement Date    |  | Day on which the performance of the Contract begins. It is specified in Section I or earlier, depending on the minute signed by the Parties in which they agree to it.                                                                                                                                                                                
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Contract Date                |  | Date on which the Contract is executed.                                                                                                                                                                                                                                                                                                               
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Natural Gas or Gas           |  | A mixture of light hydrocarbons mainly consisting of methane that is found in pools in its free form or associated with oil. When necessary, Natural Gas must be treated so that it meets the gas quality conditions specified in the Single Code on Natural Gas Transportation (RUT), and in any standards that supplement, modify, or substitute it.
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Transportation Gas Pipelines |  | For the purposes of this Contract it is the Ballena -Barrancabermeja section.                                                                                                                                                                                                                                                                         
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|GHV                          |  | Gross Heating Value of Gas in BTU/CFE.                                                                                                                                                                                                                                                                                                                
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Penalty Interest             |  | The maximum penalty interest rate for commercial transactions authorized under Colombian law for late payment.                                                                                                                                                                                                                                        
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|MBTU                         |  | 1,000,000BTU (British Thermal Units) referred to the higher calorific value.                                                                                                                                                                                                                                                                          
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Delivery Month               |  | One calendar month during which the SHIPPER has nominated the Service.                                                                                                                                                                                                                                                                                
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Entry Hub                    |  | Geographical region where the Entry Point is located.                                                                                                                                                                                                                                                                                                 
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Exit Hub                     |  | Geographical region where the Exit Point is located.                                                                                                                                                                                                                                                                                                  
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|Parties                      |  | The SHIPPER and the TRANSPORTER, their assignees and representatives.                                                                                                                                                                                                                                                                                 
|                             |  |                                                                                                                                                                                                                                                                                                                                                       
|cf/d, kcf/d, mcf/d           |  | Units of Gas flow measurement, which mean respectively: cubic feet per day, thousands of cubic feet per day, and millions of cubic feet per day.                                                                                                                                                                                                      





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|Completion Period                                  |  | Period between the Service Commencement Date and the last day of Service.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|-------------------------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Transportation Schedule                            |  | The hourly schedule for the transportation of Amounts of Energy prepared each day by a Primary Control Center in accordance with the Shippers’ Nominations and the technical feasibility of transporting the Nominations in the gas pipelines concerned.                                                                                                                                                                                                                                                                                                                                                                                                                                        
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Monthly Schedule                                   |  | The daily gas transportation program for one Month of Deliveries expressed in kcf/d that the SHIPPER must deliver to the TRANSPORTER before the Delivery Month begins.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Flow Rate                                          |  | The SHIPPER’s hourly consumption profile, which the SHIPPER shall specify and update daily within the Transportation Nomination Cycle in the TRANSPORTER’s nominations system.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|SHIPPER                                            |  | The Party that contracts the Service                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Firm Natural Gas Transportation Service or Service |  | The provision of the Natural Gas Transportation Service through the System in Firm Capacity mode in exchange for payment of the appropriate fee.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Transportation System or System                    |  | The collection of main and regional gas transportation pipelines and their branch lines, compression stations, connections, and terminals at the city gates, or installations used to provide the Service.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Representative Market Rate                         |  | The exchange rate
    between the dollar and the Colombian peso set by the Board of Governors of the Colombian Central Bank or the competent
    body.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|TRANSPORTER                                        |  | The Party that provides the Service.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Remaining Value of the Contract                    |  | Value of the Contract
    from the date of early termination until the termination date specified in number 5.3 of Section I - ESTF. Said value is
    calculated by taking the Contracted Firm Capacity multiplied by the Fixed Daily Charges to pay for the investment plus the
    Contracted Firm Capacity multiplied by the variable charges, then multiplying both values by the number of days remaining
    until the termination of the contract and adding the Contracted Firm Capacity times the daily AO&M charged times the
    number of days remaining until the termination of the contract. The results are expressed in U.S. dollars and Colombian pesos
    ($) respectively.
|                                                   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Exit Variation                                     |  | Absolute value of the difference between the Amount of Energy Confirmed and the Amount of Energy Taken in each hour by the SHIPPER.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             





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|Life of the Contract            |  | Period between the Contract Date and the date on which the Contract settlement document is signed.                                                                                                          
|------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                                |  |                                                                                                                                                                                                             
|Authorized Volume               |  | The Volume that the Primary Control Center allows to be transported during a Gas Day by a transportation subsystem or system after studying the nomination made by the SHIPPER.                             
|                                |  |                                                                                                                                                                                                             
|Unaccounted-for Volume          |  | Volume of Gas for which the SHIPPER cannot produce title of ownership or possession when requested to do so by the TRANSPORTER.                                                                             
|                                |  |                                                                                                                                                                                                             
|Volume Delivered by the SHIPPER |  | The Volume of Gas
    delivered or to be delivered to the TRANSPORTER at the SHIPPER’s expense and risk and to be taken by the SHIPPER at the
    Exit Point. This corresponds to the Transportation Volume.
|                                |  |                                                                                                                                                                                                             
|Volume Taken by the SHIPPER     |  | Volume of Gas taken by the SHIPPER at the Exit Point                                                                                                                                                        



4.          GUIDING
PRINCIPLES



4.2.1It
is in the common interest of the Parties that the Transportation System operates, in respect of reliability, safety, efficiency,
continuity, and quality, in the conditions specified in this Contract.



4.2.2The
System is an interconnected and interdependent network in which the activity of one of the agents involved in the transportation
process may affect the rights of one or more other agents. Accordingly, the main objective of the coordination of this System is
to preserve the common interest of the Parties, pursuant to the Contract and the Single Code on Natural Gas Transportation (RUT).



4 2.3The
Parties agree to use the Transportation System efficiently, pursuant to the terms of this Contract and the regulations.



CHAPTER II



PARTICULAR CONDITIONS



1.          SUBJECT
MATTER



The subject matter of this Contract is
the provision of the Firm Natural Gas Transportation Service through the System pursuant to the terms and conditions hereof.



The transportation capacity contracted
by the SHIPPER in the Ballena–Barrancabermeja section will be available as from the Service Commencement Date specified in
number 5.2 of Section I ESTF, after the TRANSPORTER has put into operation the facilities that will make it possible to increase
the capacity of the Ballena–Barrancabermeja gas pipeline, which it undertakes to do by no later than June first (1st), 2010.



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2.          SCOPE



The scope of this Contract is the Firm
Natural Gas Transportation Service through the System from the Entry Point(s) to the Exit Point(s) specified in Section I –
ESTF.



3.          APPLICABILITY



3.1           Subject
to the considerations and terms of this Contract, on each Gas Day as per the assignments of the SHIPPER’s producer and provided
that said Service is authorized by the TRANSPORTER pursuant to Chapter III number 4 (Nominations and Confirmed Amount of Energy),
the SHIPPER shall deliver to the TRANSPORTER and the TRANSPORTER shall receive at the Entry Point a Delivered Amount of Energy.
Said Gas shall be transported by the TRANSPORTER and the SHIPPER shall take the same amount at the Exit Point(s), which amount
will be known as Amount of Energy Taken.



3.2           On
each Gas Day, the SHIPPER shall deliver at the Entry Point and take at the Exit Point the Authorized Amount of Energy, according
to the Flow Rate reported by the SHIPPER.



3.3           As
soon as the gas is delivered to the TRANSPORTER at the Entry Point, the TRANSPORTER may blend said Gas with any other
gas provided that the resulting mixture delivered at the Exit Point(s) complies with the quality specifications established
in the Regulation for the time being in force, which specifications on the date of the execution of this Contract are those
set forth in Exhibit I hereto.



4.          SERVICE
INITIAL DATE



The Service Commencement Date shall be
the date specified in number 5.2 of Section I ESTF, once the TRANSPORTER has put into operation the facilities that will make it
possible to increase the capacity of the Ballena–Barrancabermeja gas pipeline, which it undertakes to do by no later than
June first (1st), 2010.



5	          ENTRY AND EXIT POINTS



The Entry Point(s) and Exit Point(s) are
specified in numbers 4.3 and 4.4 of Section I – ESTF of this Contract, as are the obligations to deliver and receive the
gas covered by this Contract.



6.          TRANSPORTATION
CHARGES



The charges for provision of the Service
covered by this Contract shall be those established in number 7 of Section I – ESTF and in number 2 of Chapter IV and shall
be subject to modification by the Energy and Gas Regulation Commission – CREG.



7.          TERM
OF THE CONTRACT

The term of the Contract is the period
between the Service Commencement Date and the last day of the Completion Period, as specified in number 5.3 of Section I –
ESTF.



8.          NOTICES



8.1           All
notifications, communications, requests, required or allowed under this Contract must be made in writing and be delivered either
personally, by fax, by registered mail or by electronic data transmission to the address specified in number 8 of Section I –
ESTF.



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8.2           The
addresses, fax numbers and e-mail addresses for notifications under this Contract, may be changed by giving the other Party at
least fifteen (15) calendar days’ prior written notice.



9.          PERFECTION
OF THE CONTRACT



9.1           This
Contract is perfected upon its execution by the representatives of the Parties.



10.         TAXES



The transportation
tax laid down in the Oil Code and in Statute 756 of 2003 and the Infrastructure Development Charge laid down in Article 15 of Law
401 of 1997 and regulated by Decree 3531 of 2004 issued by the National Government shall be paid by the SHIPPER.



As a
Transportation Contract, this Contract is exempt from stamp tax in accordance with Article 530 number 27 of the Tax Statute Legislative
Decree 624 of 1989. Each company shall be responsible for its obligations relating to income tax, industry and commerce tax, or
any other type of tax related to this Contract.



11.         GUARANTEE



By virtue
of their legal personalities and their credit and portfolio policies, both Parties agree not to require any kind of guarantee from
the other.



12.         APPLICABLE
LAW



This
Contract is governed by the Constitution, Statute 142 of 1994, the Commercial Code, the Civil Code, Resolutions adopted by the
CREG, and other applicable rules and regulations.



In
accordance with the aforementioned regulatory framework, this Contract establishes a commercial relationship between the
Parties, governed by the relevant provisions of Private Law. With regard to labor workforce, the Parties declare that the workers or
contractors hired by each of them for the performance of this Contract have no employment or contractual relationship with
the other Party and therefore are not dependent on or subordinate to the other Party. Each Party shall perform this Contract
with full autonomy in respect of technical, administrative, financial, and labor matters.



13.         REGULATIONS ADJUSTMENTS



Both
the conditions for provision of the Service and the technical and financial conditions included in this Contract are governed by
the regulations issued by the CREG or whichever other body performs its functions. Accordingly if said regulations are modified,
the Parties agree to review the conditions hereof in order to accommodate them to the regulations for the time being in force.





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14.         DOMICILE



For all contractual purposes the designated
domicile of the Parties is the city of Bucaramanga, Department of Santander.



15.         DELEGATION



For the TRANSPORTER, this Contract will
be managed by the Commercial Department of TGI S.A. E.S.P. or by whichever department may subsequently be designated for that purpose.
The SHIPPER, delegates the management of this Contract and the appointment of the officers that will be in charge of monitoring
it to the Gas Manager of ECOPETROL S.A. or to whichever other person the SHIPPER may subsequently appoint.



16.         TITLE
OF OWNERSHIP OF THE GAS



The SHIPPER guarantees that it will enjoy
free and clear ownership and possession of the Gas and be entitled to effect delivery of the Gas to the TRANSPORTER when it enters
the Transportation System. Ownership of the Gas shall be proven with the assignment of the Agent that delivers Gas to the SHIPPER’s
System.



17.         
INDEMNITY



The SHIPPER shall hold the TRANSPORTER
harmless from any and all liability and damages that may result from lawsuits, claims, and actions brought in or out of court by
third parties disputing the ownership or possession of the Natural Gas transported under this Contract. During the time that the
TRANSPORTER has the gas in its custody, the TRANSPORTER shall hold the SHIPPER harmless from any and all liability and damage that
may result from lawsuits, claims, and actions related to said gas brought in or out of court by third parties.



18.         
CUSTODY OF THE GAS



The TRANSPORTER shall have custody, possession,
and control of the Gas pursuant to the terms and conditions of this Contract and the regulations issued by the Energy and Gas Regulation
Commission (CREG), from the time at which it receives the Gas at the Entry Point until the time at which the SHIPPER takes it at
the Exit Point.



In the event of loss of Gas in the
System due to force majeure or Act of God and excusable Event, the loss shall be prorated and borne assume by the different
shippers that are using the System. This shall be done taking into account the Gas Balance calculated by the Primary Control
Center based on the Confirmed Amount of Energy.



Operational losses exceeding 1% shall
be borne assume by the TRANSPORTER. Losses of gas that do not exceed 1% will be distributed between the shippers in
proportion to the Amount of Energy transported and shall be recognized by said shippers to the TRANSPORTER in the monthly
service invoice.



19.         CHANGE
OF HUBS OR ENTRY AND EXIT POINTS



Changes
of Hubs or Entry and Exit Points may be made by written agreement between the Parties. New Hubs or Entry and Exit Points may be
added in the same way provided that they are technically and operationally feasible and that there is primary Available Capacity
in the new gas pipeline sections to be used.



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20.         
ASSIGNMENT OF THE CONTRACT



20.1       The
SHIPPER may assign the whole or part of this Contract with the TRANSPORTER’s prior written authorization. The TRANSPORTER
may assign the whole or part of this Contract with the SHIPPER’s prior written authorization, and said authorization for
the assignment shall not be refused without due cause. If, as a result of the assignment, a performance bond or bank Guarantee
has to be furnished by the assignee, the assignment shall only take effect once said Guarantee is approved in writing. The performance
bond or bank Guarantee must be issued by an insurance company or bank legally established in Colombia and supervised by the Office
of the Financial Superintendent in an amount that will be equal to the value in pesos ($) given by applying the formula contained
in Exhibit III.



20.2       The
authorized assignee must take on all the responsibilities and obligations of the SHIPPER or the TRANSPORTER (as the case may be)
under this Contract, and this requirement must be clearly stipulated in the assignment agreement.



21.         FORCE
MAJEURE OR ACT OF GOD OR EXCUSABLE EVENT



21.1       If
circumstances of force majeure, acts of God or excusable events arise directly affecting the obligations under this Contract, compliance
with said obligations shall be suspended for the period during which the force majeure, act of God or excusable event persists.



The Party affected by the event of force
majeure, act of God or excusable event shall notify the other Party of said situation within a period of twenty-four (24) hours
following the occurrence of same, and undertakes to forward all the details within five (5) business days thereafter.



For the purposes of this Contract, force
majeure and acts of God shall mean, cover and include, inter alia, the following abnormal acts, facts or events when they are unforeseeable
and irresistible, provided they are unrelated to the Parties and occur without cause or negligence, and are duly proven, such as:



a)	        Acts of nature, including landslides,
hurricanes, floods, avalanches, lightning strikes, earthquakes, fires, tsunamis, shipwrecks.



b) 	        Land, air, river or maritime transportation
disasters.



c)	        Acts or omissions by the government
or the competent legislative or judicial branch, including laws, agreements, ordinances, orders, rulings, decrees, judgments, legal
actions, regulations, issue, renewal or confirmation of permits and licenses, which directly contribute or lead to the inability
of one of the Parties to comply with all its obligations, or which seriously and unfairly undermine the interests of one or both
Parties or severely compromise their financial capacity.



d)	        Acts of civil disobedience, including
war, blockades, insurrections, mutinies, mass protests, and actions by military forces related or in response to any act of civil
disobedience.



For the purposes of this Contract, an excusable
event shall be any violent act by a third party, including, but not limited to guerrilla or terrorist acts which cause damage to
the System or the SHIPPER’S facilities at each Exit Point or which interrupt or delay compliance with the obligations undertaken
by the Parties.



21.2         The
Party affected by the event of force majeure or act of God shall do everything reasonably required to resume as soon as possible
compliance with the obligations of the Contract. Likewise, it shall make every effort to minimize or mitigate any delay or additional
costs which may be caused.



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21.3       The
provisions set forth in these clauses shall in no way release the Parties from their obligations prior to the occurrence of the
event.



22.         DIRECT
SETTLEMENT



22.1       The
Parties agree that in the event that differences arise between them, due to or caused by this Contract, they will seek direct settlement
mechanisms, such as direct negotiation or conciliation. For this purpose, the parties shall have a term of sixty (60) business
days, as from the date on which either of said parties makes a request in this respect. Said period may be extended by mutual agreement.



23.         EARLY
TERMINATION OF THE CONTRACT



23.1       Either
of the Parties may declare early termination when:



a)	         Due to circumstances of force majeure
or act of God or excusable event, the performance of the Contract is totally suspended for a continuous period in excess of three
hundred sixty-five (365) calendar days in each event, in which case no liability whatsoever shall be generated for the Parties.



b)	        By mutual agreement in writing between
the parties.



23.2      The
TRANSPORTER may declare early termination in the following cases:



a)	        When,
more than three (3) times in a period of three hundred sixty-five (365) consecutive calendar days the TRANSPORTER has
suspended the Service due to the cause set forth in sub-paragraph c of paragraph 11.3 of Chapter III or when the late payment
persists for a period of sixty (60) calendar days, in accordance with paragraph 5 of Chapter IV, except when said late
payment is the subject of controversy.



b)	        When, within a period of three hundred
sixty-five (365) calendar days, the SHIPPER has incurred indemnities in an amount which exceeds the Estimated Annual Value of the
Contract.



23.3       The
SHIPPER may declare early termination when, due to causes attributable to the TRANSPORTER, the minimum pressure guarantee set forth
in paragraph 9 of chapter III is not maintained for more than fifteen (15) consecutive days or thirty (30) non-consecutive days
per Contract year or the Gas is of poor quality.



In the event of early termination of the
Contract due to causes attributable to either of the Parties, the non-compliant Party shall recognize and pay, as sole indemnity
to the other Party by virtue of penalty, a sum equivalent to 100% of the Remaining Value of the Contract.



PARAGRAPH: Within a period of ten (10)
calendar days following the occurrence of any of the foregoing events, the Party entitled to terminate the Contract shall notify
its decision in writing to the other Party, indicating the causes of said determination and the effective termination date of the
Contract. The termination of the Contract shall not excuse or relieve the Parties from their respective obligations attributable
to the period prior to the effective date of termination.



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24.         FULL
SETTLEMENT OF THE CONTRACT



No later than thirty (30) calendar days
following the termination of the Contract Performance Term or, in the event of early termination, the Parties shall sign the respective
“Full Settlement Document”, which shall contain a summary of the most significant aspects of the performance of the
Contract, indicating the balances in favor of either of the Parties, if any. In the event discrepancies exist in this respect,
the Parties shall include applicable evidence and may resort to the dispute resolution mechanisms set forth in paragraph 22 of
this Chapter, on the thirty-first (31) calendar day following the date of completion of the Performance Period or early termination.
The Full Settlement Document signed by the Parties shall give right of execution.



In the event that, two (2) months following
the termination of the Contract Performance Period or the Early Termination, the Full Settlement Document mentioned in the preceding
paragraph has not been signed, and there is no dispute, the proposed full settlement document shall be forwarded to the address
set forth in this Contract, and if no objection is received from the SHIPPER within a period of twenty (20) business days after
having sent the proposed full settlement document, it shall be understood to have been approved.



CHAPTER III



OPERATING CONDITIONS



1.          GAS
QUALITY



1.1           The
Gas delivered by the SHIPPER to the TRANSPORTER at the Entry Point and the Gas which the TRANSPORTER delivers to the SHIPPER at
the Exit Point shall meet the quality specifications set forth in Exhibit I to this Contract.



1.2           If
the Gas delivered by the SHIPPER to the TRANSPORTER, in order for the latter to commence the Transportation of same fails to comply
with the quality specifications set forth in Exhibit I to this Contract, the TRANSPORTER shall notify the former of the quality
deficiency and shall have the right but not the obligation to reject said Gas while the situation is being rectified. If, within
a period of no more than three (3) calendar days, the SHIPPER fails to remedy the quality deficiency, the TRANSPORTER, at its discretion
and without being obligated to do so by virtue of this Contract, may: (i) carry out the activities permitting it to accept said
Gas, in which event the SHIPPER shall reimburse the TRANSPORTER for the additional costs incurred by the latter by virtue of said
activities, the estimate for which shall be agreed to in advance, or (ii) reject the Gas for transportation. In this case, the
liability of the SHIPPER shall terminate with the payment of the additional costs incurred by the TRANSPORTER.



1.3           In
the event the Gas delivered by the TRANSPORTER to the SHIPPER is not in compliance with the quality specifications set forth in
Exhibit I to this Contract due to circumstances attributable exclusively to the transportation, the SHIPPER shall notify it of
the quality deficiency and shall have the right to reject said Gas until such time as the situation is remedied, which shall be
notified in advance to the TRANSPORTER, and which shall be considered a failure of service with the same consequences as those
set forth in paragraph 10 of chapter III. In the event that within a period of no more than three (3) calendar days, the TRANSPORTER
fails to remediate the quality deficiency, the SHIPPER may, at its discretion, and without being obligated to do so by virtue of
this Contract, carry out the activities permitting it to accept said Gas, in which event the TRANSPORTER shall reimburse the SHIPPER
the additional costs which in fact were incurred by such activities, the estimate for which shall be agreed to in advance. In this
case the liability of the TRANSPORTER shall terminate with the payment of the additional costs incurred by the SHIPPER.



1.4           The
SHIPPER is responsible for arranging for the equipment required at the Entry Point for the volumetric metering and determination
of the gas quality.



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In the event that, in the judgment of the
SHIPPER, it needs to perform volumetric metering and gas quality determination at the Exit Point, the SHIPPER shall arrange, at
its own expense, for the equipment necessary for the respective calibration after reaching agreement with the TRANSPORTER on the
procedures to be followed.



1.5           The
verification of the Gas quality, both at the Entry Point and the Exit Point shall be performed by the TRANSPORTER, but the SHIPPER
reserves the right to witness the sampling and analysis. All this may be carried out notwithstanding the SHIPPER’S responsibility
to deliver Gas to the TRANSPORTER at the Entry Point outside the quality specifications established in accordance with this Contract.
Likewise, the TRANSPORTER shall verify the minimum variables determined in the RUT, the SHIPPER being responsible for ensuring
permanent and continuous compliance with all Natural Gas quality specifications set forth in this Contract for its delivery at
the Entry Point.



2.          GAS
METERING



2.1         The
SHIPPER is responsible for arranging, both at the Entry Point, through its Producer –Supplier and at the Exit Point, all
items necessary for the installation, operation and maintenance of the metering system, including calibration.



2.2         The
installation of the metering systems shall be carried out as follows:



2.2.1       EXIT
POINT 1 METERING



Until otherwise agreed to between the Parties,
the Exit Point 1 metering system shall be located at the TRANSPORTER’S COGB. Its technical and operating characteristics
shall be agreed to in a document signed by the Parties prior to the Service Commencement Date, which document shall form an integral
part of this Contract.



In the event that the Exit Point 1 metering
system and skid, installed and conditioned by the TRANSPORTER at its COGB, continues to be the official meter, the SHIPPER shall
pay a lease, administration, operation and maintenance charge for said system and metering skid, which shall be agreed to prior
to the Service Commencement Date, by means of a Lease, Operation and Maintenance Agreement executed between the TRANSPORTER and
the SHIPPER’S Barrancabermeja Refinery Management.



In the event that the SHIPPER elects to
install a meter at a location other than the COGB, initially established by the TRANSPORTER, the installation of said meter shall
be agreed to in advance between the Parties, taking into account that it shall be carried out immediately after Exit Point 1, with
the prior acceptance by the SHIPPER of the costs and investments which have not been or cannot be recovered, and those which in
fact were incurred by the TRANSPORTER for the construction and conditioning of the metering system and skid located at Exit Point
1 and for which respective supporting documents shall be provided.



In the event that it is possible for the
SHIPPER to install the official Exit Point 1 meter within the COGB, it shall pay the TRANSPORTER for the lease of the land occupied
by said meter.



2.2.2        EXIT
POINT 2 METERING



Unless otherwise agreed to between the
Parties, the Exit Point 2 metering system shall be located in the Petrosantander facilities or in the TRANSPORTER’S COGB.
The technical and operating characteristics of said meter shall be established by means of a document signed by the Parties prior
to the Service Commencement Date, which document shall form an integral part of this Contract.



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In the event that the installation and
conditioning of the Exit Point 2 metering system is carried out by the TRANSPORTER in the COGB, the TRANSPORTER shall charge the
SHIPPER a lease, administration, operation and maintenance fee for the metering system and skid, which shall be formalized by means
of a Lease, Operation and Maintenance Agreement executed between the TRANSPORTER and THE SHIPPER’S Barrancabermeja Refinery
Management. The installation and conditioning of this metering system may be carried out by the TRANSPORTER, following validation
and approval by the SHIPPER of the procedure for the execution of such activities, as well as the assurance that the performance
of said activities does not involve any risk for the storage of the gas and the continuous operation of the Barrancabermeja Refinery
owned by the SHIPPER, for which purpose a detailed risk analysis shall be carried out by the Parties within a period of twenty
(20) calendar days as from the delivery of the pertinent documentation by the TRANSPORTER to the SHIPPER.



In the event that, following the date of
execution of the Exit Point 2 metering system and skid lease, operation and maintenance contract, the SHIPPER elects to install
a meter at a location other than the COGB, the installation and conditioning of that system shall be agreed to in advance between
the Parties, taking into account that same shall be carried out immediately after Exit Point 2, with the prior acceptance by the
SHIPPER of the costs and investments which have not been or may not be recovered, and which the TRANSPORTER in fact incurred in
the construction and conditioning of the meter located at Exit Point 2 in the COGB, and for which the pertinent supporting documents
shall be submitted.



The type of meter to be installed in either
case shall be agreed to between the Parties.



In the event that, on the Service Commencement
Date, the Exit Point 2 metering system is not available, the natural gas imbalances as from the Service Commencement Date until
such time as said system is installed and operational shall be assumed by the SHIPPER, and shall be calculated as the difference
between the volumetric Gas measurements between the Centragas meters on the high pressure line, Meriléctrica and the inlet
to the TRANSPORTER’S COGB.



In those cases in which the TRANSPORTER
installs and conditions the metering systems and skids, it must possess the hardware necessary for the SHIPPER to obtain information
on line regarding the gas metering in its facilities, provided that the communications protocols are compatible.



2.3           The
obligation to read the meters and verify their calibration both at the Entry Point and at the Exit Points lies with the TRANSPORTER.
The SHIPPER reserves the right to be present during the verification of the meter calibration and for this purpose shall be notified
by THE TRANSPORTER with at least seventy-two (72) hours advance notice. The SHIPPER reserves the right to be present at the calibration
verification of the TRANSPORTER’S meters installed in Centragas, Meriléctrica and the COGB (gas to the Central-Eastern
Gas Pipeline) related to the gas balance and for this purpose shall be notified by the TRANSPORTER with at least seventy-two (72)
hours advance notice.



2.4           The
determination of volumetric quantities shall be carried out in accordance with the calculation methods established by the manufacturer
in the specific manuals for each type of meter and the recommendations of the American Gas Association AGA.



2.5           In
the event that it is verified that the SHIPPER or the TRANSPORTER has engaged in fraud in the connections or metering equipment,
the TRANSPORTER or the SHIPPER, as may be the case, may suspend the service and impose a penalty on the other Party for 100% of
the value of such fraud, notwithstanding the provisions set forth in the RUT and the filing of the pertinent legal actions. The
value of the fraud shall be determined subsequently.



2.6           The
cost associated with the installations necessary for the SHIPPER to receive the gas as of the Exit Point, including its construction,
operation and maintenance, shall be borne by the SHIPPER.



2.7           The
metering equipment shall be in compliance with metering and calibration regulations and standards currently in force.



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3.          TRANSPORTATION
REQUIREMENTS



No later than three (3) business days prior
to the end of the month preceding the Deliveries Month the SHIPPER shall send to the TRANSPORTER the estimated average transportation
requirements for the six (6) months following the Deliveries Month.



4.          NOMINATIONS
AND CONFIRMED AMOUNT OF ENERGY



The Nominations for each hour of the Gas
Day shall be made in accordance with the provisions set forth in the Single Code on Natural Gas Transportation (RUT) or subsequent
modifications thereto.



4.1         The
SHIPPER shall deliver to the TRANSPORTER the Nomination for each hour of the Gas Day by electronic data transmission prior to 04:20
pm on the day prior to the Gas Day on which it carries out the Nomination. In the event of communication problems, the SHIPPER
shall deliver the Nomination via fax or e-mail.



4.2         In
the event the TRANSPORTER does not receive the hourly Nomination from the SHIPPER or if said Nomination is not transmitted in accordance
with the terms and periods stipulated, the nomination included in the Monthly Schedule shall be considered to be the Nomination
for that Gas Day, and said Schedule shall remain in force until such time as the SHIPPER delivers a new Nomination.



4.3         The
TRANSPORTER shall totally or partially accept the Nomination in accordance with the conditions set forth in this Contract, taking
into account that in those cases in which the SHIPPER nominates quantities which are lower or equivalent to the Firm Contracted
Capacity, the Authorized Amount of Energy shall be at least the Nominated Quantity. In the event said nomination is higher than
the Firm Contracted Capacity, the Authorized Amount of Energy shall be as a minimum the Firm Contracted Capacity. The TRANSPORTER
shall notify the SHIPPER by electronic data transmission prior to 4:20 p.m., with respect to the viable Natural Gas Transportation
Schedule and the Authorized Amount of Energy. In the event of communication problems, this shall be done by fax. In the event the
TRANSPORTER fails to notify the Authorized Amount of Energy in a timely manner, the Authorized Amount of Energy shall be understood
to be the Nominated Amount of Energy. After having received this communication, and no later than 6:50 p.m. on the same day, the
SHIPPER shall forward to the TRANSPORTER a Confirmed Amount of Energy for an Amount of Energy which is less than or equal to the
Authorized Amount of Energy. In the event the TRANSPORTER does not receive a Confirmed Amount of Energy within the period mentioned
or if the Confirmed Amount of Energy is greater than the Authorized Amount of Energy, the Confirmed Amount of Energy shall be considered
to be the Authorized Amount of Energy.



The TRANSPORTER shall forward to the SHIPPER
its gas transportation schedule prior to 8:20 p.m.



If, due to causes attributable to the SHIPPER,
the stability of the Transportation System is affected, the SHIPPER shall assume the cost for which it is proportionally liable
of the damages caused to the TRANSPORTER and the other System Agents by virtue of said situation. In order to determine the final
liability of the SHIPPER, it shall be necessary to verify the SHIPPER’S consumption as well as that of the other shippers
against the nomination which each of them shall submit, as set forth in the RUT. The TRANSPORTER shall supply all the information
necessary to carry out this analysis.



The SHIPPER shall guarantee that the gas
consumption rate in its facility is maintained at all times within the operating limits of the metering system installed. In the
event the consumption rate is outside the meter range, or is outside the operating limits, the SHIPPER shall indemnify the TRANSPORTER
for the gas which is not metered and shall be responsible for the operating problems caused by such situation. The Parties agree
that in order to determine the quantity of power consumed which could not be metered, a power balance shall be carried out on each
of the Exit Points indicated under paragraph 4.4 of Section I, taking into account the following meters:



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For Exit Point 1, the meters installed
in Centragas for the low pressure line (FQI-3-02 and FQI-3-03)m, gas meter to Ferticol (UPBM-11) and gas meter to Gases de Barrancabermeja
(UPBM-10).



For Exit Point 2, the meters installed
in Centragas for the high pressure line (FQI-3-01 and FQI-3-04), Meriléctrica meter (UPBM-12) and gas meter to the Central-Eastern
gas pipeline (UPBM-02).



In addition, if the SHIPPER needs to increase
its consumption capacity (both pressure and volume increase), it shall assume all the costs required to carry out the Exit Point
and Connection.



PARAGRAPH 1: The Parties agree that the
schedules and the Nomination process may be modified in the future, based on the provisions established by the CREG on the matter.



5.        CALCULATION
FOR VARIATIONS



During the first twenty (20) calendar days
of each month following the Deliveries Month, the TRANSPORTER shall calculate the SHIPPER’S Output Variation for each Gas
Day of the Deliveries Month.



6.        COMPENSATION
FOR VARIATIONS



When the cases referred to in this paragraph
arise, the TRANSPORTER may notify and coordinate with the SHIPPER the operating corrections necessary in order to rectify the Shipper’s
Output Variation. Compliance with the agreement will exonerate the SHIPPER from compensations.



In the event that the SHIPPER fails to
apply the operating corrections to the satisfaction of the TRANSPORTER, it shall apply the compensation set forth below:



For each hour of the Deliveries Month Gas
Day, when the SHIPPER’S Output Variation exceeds 4% of the Confirmed Amount of Energy, the SHIPPER shall pay a charge equivalent
to five (5) times the Reference Capacity Daily Charge multiplied by the volume equivalent to the excess in the Output Variation
in excess of 4%.



These payments shall not grant the SHIPPER
the right to incur Output Variations.



When the CREG approves the tables of Compensation
for Output Variations caused by the SHIPPER, they shall begin to be applied and shall replace those initially stated. Said compensation
shall be calculated daily and shall be invoiced monthly, as set forth in paragraph 3 of Chapter IV.



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7.          BALANCE
ACCOUNT



7.1         During
the first twenty (20) calendar days of each month following the Deliveries Month, the TRANSPORTER shall calculate the Power Imbalances
for the Deliveries Month. The Energy Balance Account shall be updated daily in accordance with the measurements made by the TRANSPORTER.



7.2         The
SHIPPER undertakes to supply to the TRANSPORTER the information requested from it by the latter when it considers necessary and
which the SHIPPER is able to supply, for the purpose of calculating the Imbalances. At the discretion of the TRANSPORTER, this
information shall be provided in electronic format.



7.3         The
TRANSPORTER shall maintain the SHIPPER’S Balance Account duly updated.



8.          COMPENSATION
FOR IMBALANCES



In the event that the Power Imbalance exceeds
0.5% in the Deliveries Month, the TRANSPORTER may first seek to reach an agreement with the SHIPPER with respect to the accounting
procedures to be followed, in order to handle, reconcile and eliminate the Power Imbalances. In the event that said situation is
not rectified to the satisfaction of the TRANSPORTER, the TRANSPORTER may require the SHIPPER to pay, by way of indemnity, a sum
equal to the excess multiplied by the Reference Capacity Daily Charge.



Such payment shall not grant the SHIPPER
the right to incur Power Imbalances.



PARAGRAPH I. The amounts paid for each
Deliveries Month by virtue of Indemnities owed by the SHIPPER shall be invoiced monthly together with the amount of the Service,
as set forth in paragraph 3 of Chapter IV.



9.          PRESSURE
AT THE ENTRY AND EXIT POINTS



9.1         The
TRANSPORTER shall make available to the SHIPPER the Gas at the Exit Point at the minimum defined pressure of 350 Psig.



9.2         From
the Exit Point onward, the SHIPPER shall take the measures necessary to guarantee its capacity to take from the system the volume
of the transportation capacity contracted.



9.3         The
SHIPPER, through its producer, shall make the necessary arrangements for the Gas to enter the system at the Entry Point without
exceeding the maximum operating pressure defined as 1200 psig. The TRANSPORTER may decline to receive Gas which is not in compliance
with this pressure requirement.



10.        NON-COMPLIANCE
DUE TO LOW PRESSURE OR POOR GAS QUALITY AT THE EXIT POINT



In the event that the pressure at the Exit
Point is lower than the minimum pressure defined in paragraph 9 of this Chapter, and for this reason the SHIPPER is unable to receive
the amount of Power confirmed, or in the event that the SHIPPER elects to exercise the right not to receive the Gas in accordance
with paragraph 1.3 of Chapter III, the procedure below shall be followed:



10.1       The
TRANSPORTER shall not make any charge whatsoever for the difference between the Authorized Volume and the Volume Received by the
SHIPPER.



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10.2       The
SHIPPER shall have the right to request in the Nomination, within a period of (60) calendar days following the date on which the
non-compliance arises at the Exit Point, an Amount of Energy in excess of the Nominated Amount of Energy for the same quantity
as the Amount of Energy Not Received, under the conditions set forth in paragraph 4 of this Chapter, provided this does not affect
other shippers who have engaged the Firm Service. For each day on which the TRANSPORTER fails to accept the nomination of the amount
of energy not received by the SHIPPER, the aforementioned 60-day period shall be extended by one additional day.



10.3       The
SHIPPER shall have the right to have the TRANSPORTER recognize the following items:



a)	         Payment of the penalties, surcharges,
indemnities and/or excess costs actually incurred by the SHIPPER with respect to its clients and/or the GCB, as a direct consequence
of the events set forth in this clause.



b)		         The value of the investments or expenses
actually incurred by the SHIPPER to carry out the work necessary to make good or replace the amount of Gas not transported as a
direct consequence of the events set forth in this clause.



PARAGRAPH 1: The Transporter shall
deduct the foregoing items from the next transportation invoice.



11.         SUSPENSION



11.1         The
Parties may, by mutual accord, suspend the obligations set forth in this Contract.



11.2         The
SHIPPER may suspend its obligations in the following cases:



a)	         	For maintenance of its facilities
for a period of no more than seven hundred twenty (720) consecutive or non-consecutive hours at each Exit Point during each Contract
Year. For this purpose, the SHIPPER shall notify its maintenance schedule to the TRANSPORTER monthly.



b)		         Due to force majeure or act of God
or excusable event.



c)		         Due to the inspection and maintenance
activities of its meters at the Exit Points, which affect the gas flow to the SHIPPER, for the duration of such activities.



11.3       The
TRANSPORTER may suspend its obligations in the following cases:



a)		         To carry out technical repairs or
maintenance at the facilities which form a part of the System, for a period of no more than seven hundred twenty (720) consecutive
or non-consecutive hours at each Exit Point per Contract year. To this effect, the TRANSPORTER shall notify its maintenance schedule
monthly to the SHIPPER, which schedule shall be sent by no later than the last business day of the Month prior to the month during
which the maintenance is to be performed, indicating the date, duration and estimated capacity of the maintenance.



b)		         Due to force majeure, act of God
or excusable event.



c)		         Due to delinquency in any payment
by the SHIPPER in excess of ten (10) calendar days, except when such payment is the subject of dispute.



d)		         Due to failure to renew on a timely
basis the guarantees required by the TRANSPORTER, or to submit the premium payment certificate, in the event that this contract
is assigned by the SHIPPER.



11.4        The
events set forth in sub-paragraphs a) and b) of paragraphs 11.2 and 11.3 shall suspend the obligations of both Parties. The provisions
set forth in this paragraph 11 shall not exempt the Parties from their payment obligations caused up to the time of the suspension.



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11.5         Except
in unforeseen cases, the suspending Party shall notify the suspension to the other Party with at least forty-eight (48) hours advance
notice. In unforeseen cases, the notification shall be made as quickly as possible.



11.6         The
suspension shall cease when the cause which originated it ceases, for which purpose the suspending Party shall notify the other
Party of the cessation of the suspension and the Contract shall be automatically resumed under the terms in force prior to the
suspension.



11.7         Any
non-compliance or delay in compliance of any obligation related to the metering for which the SHIPPER is responsible for a period
in excess of 30 calendar days shall likewise be cause for suspension of the Service.



CHAPTER IV



FINANCIAL CONDITIONS



1.          APPLICABILITY
OF THE SERVICE



The SHIPPER may require the Service described
herein each Gas Day during the Contract Performance Period. To this effect, Nominations shall be made as described in paragraph
4 of Chapter III. The Service shall not be subject to restrictions or interruptions except as set forth in paragraph 11 of Chapter
III, provided the SHIPPER is able to demonstrate at the request of the TRANSPORTER that it has title to the volume of Gas to be
transported, which requirement shall be verified in accordance with the provisions set forth in Paragraph 16 of Chapter II of this
Contract. In the event that the SHIPPER is unable to comply with this condition, the SHIPPER shall be considered in breach for
an amount equivalent to the Volume Deficiency and the TRANSPORTER shall have the right to refrain from authorizing the Service
up to a volume equivalent to the Volume Deficiency.



The TRANSPORTER shall not be obligated
to transport a volume of Gas greater than the Firm Contracted Capacity, unless it has agreed to do so during the Transportation
Nomination Cycle.



PARAGRAPH: Occasional Transportation



A.           At
its discretion, the TRANSPORTER may authorize the transportation of volumes in excess of the Firm Contracted Capacity for a specific
Gas Day, in accordance with the SHIPPER’s request within the Nomination process, which shall be invoiced as indicated in
paragraphs 2.3 and 2.4 hereinbelow.



2.          CHARGES



2.1         The
charges caused by this Contract include the Fixed Charge, Variable Charge and AO&M Fixed Charge set forth in Section I-ESTF.



2.2         The
value of the Service during the Deliveries Month; and which is invoiced monthly corresponds to the sum of the three items.



2.2.1       Fixed
Charge, equivalent to the Firm Contracted Capacity multiplied by one twelfth of the Fixed Charge described in paragraph 7.1 of
section I-ESTF for the respective Transportation Gas Pipeline. The Fixed Charge shall be applicable as from the Service Commencement
Date, regardless of whether it is used or not.



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2.2.2         Variable
Charge, which is equivalent to the Volumes Delivered by the SHIPPER, multiplied by the Variable Charge described in paragraph 7.2
of Section I-ESTF for the respective Transportation Gas Pipeline. The Variable Charge shall be applicable as from the Service Commencement
Date.



2.2.3         AO&M
Fixed Charge, equivalent to the Firm Contracted Capacity, multiplied by one twelfth of the AO&M Fixed Charge described in paragraph
7.3 of Section I-ESTF for the respective Transportation Gas Pipeline. The AO&M Fixed Charge shall be applicable as from the
Service Commencement Date, regardless of whether or not it is used.



2.3           In
the event that, for any Gas Day, the TRANSPORTER authorizes an average daily transportation greater than the Firm Contracted Capacity
as set forth in the Single Paragraph of paragraph 1 of this Chapter, the transportation of this greater daily volume shall have
a special charge in dollars and a special charge in pesos of USD 0.793/kpc plus USD1.091/kpc corresponding to the maximum rate
of the 0% fixed - 100% variable pair set forth in CREG Resolution 125 of 2003. The preceding charges are as of December 31, 2007
applicable to the year 2008.



2.4           The
Charge Amounts set forth in dollars shall be taken to three (3) decimal places as follows: if the fourth decimal place is less
than 5, the third decimal place is maintained, and if the fourth decimal place is greater than or equal to 5, the third decimal
place is increased by 1, and the charge amounts expressed in pesos shall be taken in round numbers, which figures shall be updated
in accordance with the provisions set forth in paragraphs 5.7 and 5.8 of Article 5 of CREG Resolution 001 dated January 20, 2000.



2.5           The
TRANSPORTER agrees that, in the event it has primary capacity available at a better rate than that agreed to in this Contract,
it will apply said rate to the SHIPPER as of the date on which it starts to apply said rate to third parties, notwithstanding that
the parties may execute agreements between themselves or with third parties to promote market growth, in which event said conditions
shall not affect the rates of this contract.



2.6           In
the event that the TRANSPORTER’S Policy for the interruptible transportation establishes interruptible transportation rates
lower than those agreed to in this contract, the TRANSPORTER shall adjust the charges to the SHIPPER, deducting from the fixed
charges to be paid by the SHIPPER the amount of the income obtained by the TRANSPORTER under the interruptible transportation modality
and for a capacity equivalent to the lesser amount between the capacity not sold by the SHIPPER and the capacity sold as interruptible
by the TRANSPORTER. In order to comply with the provisions set forth in this paragraph, the SHIPPER undertakes to publish daily
in the TRANSPORTER’S Electronic Operations Bulletin (BEO) its surpluses of capacity for resale.



PARAGRAPH: The provisions set forth in
the preceding paragraph shall not apply when the TRANSPORTER wishes to develop or promote a specific market, previously approved
by an institutional policy of the TRANSPORTER.



3.          INVOICING



3.1         The
TRANSPORTER shall invoice monthly the amount of the Service, the indemnities caused by Output Variations, Imbalances, gas losses
and other services during the prior Deliveries Month, in Colombian pesos, utilizing for the invoicing of the portion of the charges
established in dollars, the representative market rate certified by the Bureau of Finance for the last day of the month in which
the transportation is carried out.



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3.2         The
invoice shall be based on the sum total of the Daily Amounts Requested and Accepted by the SHIPPER at the Entry Point.



3.3         The
invoice must contain the minimum requirements set forth in the Single Code on Natural Gas Transportation (RUT)
and, once issued by the TRANSPORTER, shall be enforceable per se.



3.4         For
the purposes of invoicing the solidarity contribution factor to the SHIPPER, the TRANSPORTER shall use the information for the
month immediately prior to the Delivery Month, and shall make the respective adjustments to the billing the following month.



3.5         For
all the purposes of this Contract, the invoice shall be considered delivered by the TRANSPORTER to the SHIPPER on the date on which
it is forwarded electronically or by fax to the fax number recorded for that purpose in Section I – ESTF. The TRANSPORTER
shall simultaneously submit the original invoices with their respective supporting documentation by registered mail, not later
than the calendar day following the fax transmission. Failure to send the original invoice within the established timeframe shall
result in an extension of the payment term for a period equal to that of the delay.



4.          PAYMENTS



The SHIPPER shall pay the invoice in the place and manner that
the TRANSPORTER designates for that purpose, in Colombian pesos, no more than fifteen (15) calendar days after the invoice is delivered.



If the SHIPPER disputes an invoice or part
of it or one of its line items before the payment due date, the SHIPPER may abstain from paying the disputed sum, stating the grounds
for the rejection. If the Parties reach an agreement regarding the disputed amount within the next eight (8) business days, and
if the dispute is resolved in favor of the TRANSPORTER, the SHIPPER shall pay the amount owed not later than the ninth (9th)
business day following resolution of the dispute, with the corresponding penalty interest, if appropriate.



If the Parties do not reach an agreement
regarding the disputed amount, the SHIPPER must pay, at a minimum, the undisputed amount of the invoice corresponding to the transportation
service provision in the same period established above and may, once the payment is made, resort to the procedures set forth in
Chapter II, paragraph 22.



Should the SHIPPER prevail in the claim,
the TRANSPORTER must repay the overpaid amount, if any, within the five (5) business days following the mutual agreement or judicial
decision, as the case may be, with the corresponding penalty interest from the date on which the payment was made.



Should the TRANSPORTER prevail in the claim,
the SHIPPER must pay the sum pending payment, if any, plus the penalty interest for the unpaid amount from the due date of the
invoice containing the disputed sum until the corresponding decision is issued. The payment shall be made within five (5) business
days following the decision that settles the dispute.



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5.          DEFAULT



If the Party obligated to do so does
not pay on the dates fixed for that purpose any sum owed to the other Party pursuant to the provisions of this Contract, it
shall pay Default Interest. Default Interest shall be applied to the balance of the sum owed in pesos and in
proportion to the time transpired from the date on which the payment should have been made, according to the stipulations
herein, until the date on which the payment is made.



When the SHIPPER defaults, the TRANSPORTER
shall have the right to suspend the Service as of the eleventh (11th) calendar day of the default. If the default continues
for fifty (50) more calendar days, the TRANSPORTER may terminate the Contract and enforce the guarantees, should this Contract
be assigned by the SHIPPER.



PARAGRAPH: The debtor shall be
considered in default without the need for any formal notice.



6.          ESTIMATED
VALUE OF THE CONTRACT



It is considered equal to the Contracted
Firm Capacity multiplied by the Fixed Charges that compensate the investment plus the Contracted Firm Capacity multiplied by the
variable charges for three hundred sixty-five (365) days and the Contracted Firm Capacity for the AO&M expenses, expressed
in U.S. dollars and in Colombian pesos ($).



7.          DISCOUNTS
ON THE FIXED CHARGE



7.1         If
during the Performance Period of the Contract the Excusable Events, Force Majeure, or Acts of God set forth in Chapter II, number
21, occur, or the TRANSPORTER fails to deliver to the SHIPPER the Authorized Volume in an amount equal to the Contracted Firm Capacity,
the TRANSPORTER shall give the SHIPPER a discount, in dollars and pesos, for each Gas Day the events or failures are in effect,
according to the following formula:



Discount in dollars = [Contracted Firm Capacity (kcf/d) –
Volume Received by the SHIPPER (kcf/d)] x (Fixed Charge (USD/kcf/d-year) / 365 days)



Discount in pesos = [Contracted Firm Capacity
(kcf/d) – Volume Received by the SHIPPER (kcf/d)] x (Charge for AO&M (Pesos ($)/kcf/d-year) / 365 days).



7.2         If
the TRANSPORTER refuses to accept delivery of the SHIPPER’s Gas or restricts the SHIPPER’s deliveries based on
the right of refusal in Chapter III, paragraph 1, regarding Gas Quality, the TRANSPORTER shall not be obligated to provide
any Fixed Charge discount.



7.3         Likewise,
in the event the Contract obligations are suspended under the terms of Chapter III, paragraph 11, by either of the
Parties, this shall give rise to a discount on the fixed charges corresponding to both pesos and dollars, with regard to the
capacity that the TRANSPORTER did not have available, applied as follows:



Discount in dollars = [Contracted Firm
Capacity (kcf/d) – Available Firm Volume that the TRANSPORTER reported during the maintenance (kcf/d)] x (Fixed Charge (USD/kcf/d-year)
/ 365 days)



Discount in pesos = [Contracted Firm
Capacity (kcf/d) – Available Firm Volume that the TRANSPORTER reported during the maintenance (kcf/d)] x (Charge for
AO&M (Pesos ($)/kcf/d-year) / 365 days).



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8.          SIGNATURES



In witness whereof, the Parties sign this Contract in two originals
with identical content, on October first (1st), 2008.



|The Transporter                             |  | The Shipper               
|------------------------------------------- |  | --------------------------
|                                            |  |                           
|[signature]                                 |  | [signature]               
|JORGE ARMANDO PINEDA SÁNCHEZ                |  | CAMILO MARULANDA LÓPEZ    
|C.C. [Citizen ID] 91.241.552 of Bucaramanga |  | C.C. 10.008.868 of Pereira
|                                            |  | [initials]                
|[initials]                                  |  |                           



|Prepared by: | DCO/Maria C. Gomez G.   
|------------ | ------------------------
|Reviewed by: | DCO/Sonia R. Sanabria M.
|             | SEG/Luis M. Carvajal A. 
|Approved by: | PRE/Jorge A. Pineda S.  

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EXHIBIT I



SPECIFICATIONS REGARDING NATURAL GAS



TO BE TRANSPORTED VIA A GAS PIPELINE



|SPECIFICATIONS                                           |  | International System |  | British System    
|-------------------------------------------------------- |  | -------------------- |  | ------------------
|Minimum Gross Heating Value (GHV). (Note 1)              |  | 35.4 MJ/m3           |  | 950 BTU/ft3       
|Maximum Gross Heating Value (GHV). (Note 1)              |  | 42.8 MJ/m3           |  | 1,150 BTU/ft3     
|Liquid content. (Note 2)                                 |  | Free of liquids      |  | Free of liquids   
|Total maximum H2S content                                |  | 6 mg/m3              |  | 0.25 grain/100 cfs
|Total maximum sulphur content                            |  | 23 mg/m3             |  | 1.0 grain /100 cfs
|CO2 content, maximum, in % volume                        |  | 2%                   |  | 2%                
|N2 content, maximum, in % volume                         |  | 3%                   |  | 3%                
|Inert content, maximum, in % volume. (Note 3)            |  | 5%                   |  | 5%                
|Oxygen content, maximum, in % volume                     |  | 0.1%                 |  | 0.1%              
|Maximum water vapor content                              |  | 97 mg/m3             |  | 6.0 lb/mcfs       
|Delivery temperature, maximum                            |  | 49 oC                |  | 120 oF            
|Delivery temperature, minimum                            |  | 7.2 oC               |  | 45 oF             
|Maximum content of dust and suspended material. (Note 4) |  | 1.6 mg/m3            |  | 0.7 grain/1000 cf 



|Note 1: All data regarding cubic meters or cubic feet of gas
        refer to Standard Conditions, that is, 14.65 psia and 15.6 oC (60 oF),
        
        Note 2: Liquids may be: hydrocarbons, water, and other contaminants
        in liquid state.
        
        Note 3: The sum of the contents of CO2, nitrogen, and oxygen
        are considered inert contents.
        
        Note 4: The maximum particle size is 15 microns.
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



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EXHIBIT II



MEASUREMENT



The purpose of this Exhibit is to establish
a general guide for the design, installation, operation, calibration, and maintenance of the gas measurement systems that are used
for transfer of custody.



It summarizes the minimum requirements
that must be met to guarantee measurement quality and reliability, enabling the systems to be within the margins of error that
the standards and recommendations applicable to natural gas measurement establish.



It is important to note that in all
cases, the document that is the basis for measurement and invoicing is Resolution CREG 071 of 1999 Single Code on Natural Gas
Transportation (“RUT”).



1. Definitions:

The general definitions in the area of
metrology shall be those referred to in the Vocabulario Internacional de Metrología (VIM) International Vocabulary
of Metrology, published by ICONTEC as Colombian Technical Standard NTC-2194 (most recent edition).



In the case of specific definitions applicable
to metrology and measurement technology, the most recent edition of the glossaries of the respective standards and applicable recommendations
shall be used as a reference.



2. Applicable Technical References

In the area of measurement, the most recent
versions of the standards and recommendations published by the following institutions shall be used:



| |  ̈ | ICONTEC
| | - | -------

| |  ̈ | ISO
| | - | ---

| |  ̈ | API
| | - | ---

| |  ̈ | AGA
| | - | ---

| |  ̈ | ASTM
| | - | ----

| |  ̈ | ISA
| | - | ---

| |  ̈ | ASME
| | - | ----

| |  ̈ | ANSI
| | - | ----

| |  ̈ | GPA
| | - | ---

| |  ̈ | NEMA
| | - | ----

| |  ̈ | IEC
| | - | ---



3. Traceability of Measurements



All the measurements must be traceable
to national and/or international standards.



This will be accomplished by the use of
accredited laboratories in the country, recognized by the Superintendency of Industry and Commerce or the body that replaces it,
for the performance of calibrations, analysis, and testing. Should the means or infrastructure not be available at the national
level, international laboratories recognized by the equivalent body abroad shall be used.



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The master instruments used in the verification
activities must have a margin of error at least two (2) times smaller than that of the instruments to be evaluated. In addition,
they must be included in a measurement assurance plan to guarantee their reliability, bearing in mind the masters are used to determine
the maximum calibration interval.



2. Energy Measurement



2.1 Entry Points

All the Entry Points must have an on-line
gas chromatograph, as set forth in paragraph 5.2.1 of the RUT.



The chromatograph and the sampler must
be selected, installed, and operated in a manner that guarantees the capture of representative samples and the performance of analysis
with a low margin of error for measurements, pursuant to the applicable technical references in effect.



The on-line chromatograph must be integrated
with the flow computer for the purposes of precise volume and energy measurement.



The chromatograph calibration gas must
be a Certified Reference Material, and its analytical characteristics shall be better than the chromatograph’s technical
specifications in order to allow its use as a master standard.



2.2 Exit Points



A monthly adjustment of the composition
shall be performed at the exit points that operate with fixed chromatography. The composition shall be obtained from chromatographic
sampling and analysis or via the monthly average taken from a nearby chromatograph that measures the same current with a negligible
time difference regarding the period between adjustments.



The installation of on-line chromatographs
at the exit points, where required, by mutual agreement of the parties, shall be the responsibility of the shipper and shall be
subject to the criteria indicated above for the Entry Points.



3. Volumetric Measurement



For the measurement of gas volume, only
those meters that are recognized for use in custody transfer operations and are supported by a standard and/or recognized technical
recommendation shall be used.



The instruments for measurement of magnitudes
other than volume (for example: pressure, temperature, density) but that influence the measurement result must be integrated with
the flow computer.



Orifice plate measurement systems must
comply with the most recent version of AGA Report No. 3 and have a plate-holder element that allows the performance of inspections
and/or replacements without interruption of the flow. All plate measurement systems must have an inspection certificate issued
by a recognized body that guarantees system compliance with the tolerances expressed in the standard.



Ultrasonic meters must have multiple trajectories
and be calibrated in a recognized laboratory, under conditions similar to operating conditions. Sufficient space shall be provided
for their installation, operation, and maintenance, and the tools necessary for on-the-spot removal of the transducers shall also
be provided, in order to internally inspect, clean, and/or replace them in case of defect. Likewise, they must comply with the
most recent version of AGA Report No. 9.



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Turbine-type meters must be calibrated
in a recognized laboratory, under conditions similar to operating conditions. The meter must have an oil injector or pump that
guarantees periodic lubrication of the bearings. Likewise, they must comply with the most recent version of AGA Report No. 7.



Mass meters must be calibrated in a recognized
laboratory. When technically justifying the appropriateness of their use, it must be shown that the effect of the density variations
on the volume calculation from the mass does not affect the measurement more than the ±1% margin of error indicated in the
RUT. Otherwise, installation of equipment for ongoing determination of the specific gravity of the gas shall be required, integrated
with the flow computer. Likewise, they must comply with the most recent version of AGA Report No. 11.



Rotameters may be calibrated to atmospheric
pressure. A pressure gauge shall be installed on the rotameters for measurement of differential pressure, between the meter inlet
and outlet. Likewise, they must comply with the most recent version of ANSI standard B109.3.



Diaphragm meters shall not be used as it
is not possible to diagnose their performance throughout their useful life. The use of rotameters is recommended in their stead.



All of the measurement systems must have
full bore and by-pass valves that facilitate operation and the execution of calibration, maintenance, and inspection activities.
Likewise, the space and conditions around the system must be safe and of an appropriate size for access to the system and for the
execution of future inspections and maintenance.



Measurement systems that may fail due to
excessive acceleration in their components (for example: turbine, rotameter, diaphragm, mass, etc.) must have a restriction element
for protection in case of over-revolution.



The method to guarantee transparency in
measurements that have a by-pass without an alternate meter shall be decided by mutual agreement. The installation of seals, blind
plates, or electronic locks integrated with the SCADA is recommended.



After a repair, the parties shall assess
whether it is necessary for the meter to be recalibrated in a recognized laboratory. Should this be necessary, the system owner
shall be responsible for the associated costs.



Should operating conditions change from
the time when the measurement system was originally designed, causing its performance to not comply satisfactorily with the required
measurement capacity and/or margin of error, the system shall be redesigned or replaced by one that satisfies the new operating
condition. The system owner shall be responsible for the associated costs.



The flow computer must be approved pursuant
to its compliance with the most recent edition of API MPMS standard 21.1 and be compatible with the Transporter’s SCADA System
communication protocol. Therefore, the parties shall evaluate the communication protocol with the most appropriate flow computer,
among which shall be considered Bristol Babcock’s BSAP.



4. Measurement of Other Variables



4.1 Temperature



Flow temperature must be determined according
to the applicable technical references. The determination of error and the measurement margin of error associated with the flow
temperature include the unit made up of the sensor and the transmitter or analog-digital converter, forming a single loop.



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4.2 Pressure



Static pressure must be determined according
to the applicable technical references. Should absolute pressure transmitters not be used, it shall be determined from the average
atmospheric pressure of the site where the measurement system will be installed, using the best and most up-to-date resources for
its precise characterization (for example: in-situ monitoring, correlation by altitude, GPS, etc.).



4.3 Compressibility Factor



The gas compressibility factor shall be
determined using the methods described in the most recent edition of AGA Report No. 8.



4.4 Speed of Sound in Natural Gas



For the purpose of ultrasonic meter diagnosis,
the speed of sound in the natural gas shall be calculated using the methods described in the most recent edition of AGA Report
No. 10.



4.5 Heating Value and Composition

At the points where there is on-line chromatography,
the heating value shall be taken from the chromatograph and included in the flow computer calculations. The heating value shall
be evaluated according to the most recent edition of ASTM standard D3588.



At those points with fixed chromatography,
the parameters associated with gas composition and required for the calculation of its properties shall be adjusted monthly. These
shall be obtained by chromatographic sampling and analysis or using the monthly average taken from a nearby chromatograph that
measures the same current with a negligible time difference regarding the period between adjustments.



5. Margin of Error in Measurements

The measurement systems must operate within
a combined margin of error of ±1%. To that end, the expanded margin of error, associated with the volume and energy measurements,
and stated for a confidence level of 95% must be less than 1%.



The Guía para la expresión de
la Incertidumbre en las Mediciones (GUM) Guide for the Statement of Margin of Error in Measurements, published by ICONTEC
in the most recent edition of the Colombian Technical Guide GTC-51, shall be used to evaluate the interval that characterizes the
dispersion of values that may reasonably be attributed to the measurement system as results.



6. Calibration of Measurement Equipment



6.1 First Calibration

The first calibration of the meter and
of the instruments and equipment associated with the measurement system shall be performed in a recognized laboratory before their
installation.



6.2 Verifications

Verification of metrological performance,
accuracy, and the internal condition of the measurement systems shall be performed periodically, starting with the following intervals:



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| |  ̈ | Meters (primary element): annual inspection
| | - | -------------------------------------------

| |  ̈ | Other instruments and flow computer: monthly
verification
| | - | ---------------------------------------------------------



After the first year, the initially-established
verification periods may be extended up to a maximum of three (3) years for the meters and three (3) months for the other instruments
and flow computer, provided the results of the inspection and historical data fully support the action.



Likewise, once extended, the periods may
be shortened if for any reason the performance of the elements degrades in such a way that the extended interval would not allow
appropriate metrological monitoring of the system.



Should there be instruments, equipment,
and/or components that do not maintain their stability between successive one (1)-month periods, the owner shall proceed to repair
or replace the element with one of better quality and stability.



7. Conservation of Readings



The TRANSPORTER and the SHIPPER shall keep
original documents or supporting documentation regarding all testing or graphic data, or any other similar type of record, on optical
and/or magnetic media for a period of four (4) years or the shortest period permitted by the applicable rules of the Energy and
Gas Regulatory Committee (CREG), counted from the date on which the evaluation is performed.



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EXHIBIT III



GUARANTEE AMOUNT



|Guarantee Amount= | (Fixed Charge/365*RMR+Variable Charge*RMR+AOM/365) * 70 days * Q +
|----------------- | ------------------------------------------------------------------
|                  | (Fixed Charge/365*RMR+AOM/365) * 15 days * Q, where               



Guarantee Amount: Guarantee Amount in Pesos ($)



Fixed Charge: Fixed Charge in USD/kcf/d-year, takes effect when
the guarantee is established



Variable Charge: Variable Charge in USD/kcf, takes effect when
the guarantee is established



AOM: Fixed Charge for Administration, Operation, and Maintenance
in Pesos ($)/kcf/d-year, takes effect when the guarantee is established



RMR: Representative Market Rate for the day on which the guarantee
is established, expressed in Pesos ($)/USD.



Q: Contracted capacity, in kcf/d.



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TABLE OF CONTENTS



NATURAL GAS TRANSPORTATION CONTRACT



|SECTION I – ESTF                    | 1 
|----------------------------------- | --
|                                    |   
|Natural Gas Transportation Contract | 1 
|                                    |   
|CHAPTER I                           | 3 
|                                    |   
|GENERAL CONDITIONS                  | 3 
|                                    |   
|1. IDENTIFICATION OF THE PARTIES    | 3 
|                                    |   
|2. RECITALS                         | 3 
|                                    |   
|3. DEFINITIONS                      | 5 
|                                    |   
|4. GUIDING PRINCIPLES               | 8 
|                                    |   
|CHAPTER II                          | 8 
|                                    |   
|PARTICULAR CONDITIONS               | 8 
|                                    |   
|1. PURPOSE                          | 8 
|                                    |   
|2. SCOPE                            | 9 
|                                    |   
|3. APPLICABILITY                    | 9 
|                                    |   
|4. SERVICE COMMENCEMENT DATE        | 9 
|                                    |   
|5. ENTRY AND EXIT POINTS            | 9 
|                                    |   
|6. TRANSPORTATION CHARGES           | 9 
|                                    |   
|7. TERM OF THE CONTRACT             | 9 
|                                    |   
|8. NOTICE                           | 9 
|                                    |   
|9. PERFECTION OF THE CONTRACT       | 10
|                                    |   
|10. TAXES                           | 10



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|11. GUARANTEE                                      | 10
|-------------------------------------------------- | --
|                                                   |   
|12. APPLICABLE LAW                                 | 10
|                                                   |   
|13. CHANGES TO REGULATIONS                         | 10
|                                                   |   
|15. DELEGATION                                     | 11
|                                                   |   
|16. OWNERSHIP OF THE GAS                           | 11
|                                                   |   
|17. INDEMNITY                                      | 11
|                                                   |   
|18. CUSTODY OF THE GAS                             | 11
|                                                   |   
|19. CHANGES OF HUBS AND ENTRY OR EXIT
    POINTS   | 11
|                                                   |   
|20. ASSIGNMENT OF THE CONTRACT                     | 12
|                                                   |   
|21. FORCE MAJEURE OR ACT OF GOD OR EXCUSABLE EVENT | 12
|                                                   |   
|22. DIRECT SETTLEMENT                              | 13
|                                                   |   
|23. EARLY TERMINATION OF THE CONTRACT              | 13
|                                                   |   
|24. FULL SETTLEMENT OF THE CONTRACT                | 14
|                                                   |   
|CHAPTER III                                        | 14
|                                                   |   
|OPERATING CONDITIONS                               | 14
|                                                   |   
|1. GAS QUALITY                                     | 14
|                                                   |   
|2. GAS METERING                                    | 15
|                                                   |   
|3. TRANSPORTATION REQUIREMENTS                     | 17
|                                                   |   
|4. NOMINATIONS AND CONFIRMED AMOUNT OF ENERGY      | 17
|                                                   |   
|5. CALCULATION FOR VARIATIONS                      | 18
|                                                   |   
|6. COMPENSATION FOR VARIATIONS                     | 18
|                                                   |   
|7. BALANCE ACCOUNT                                 | 19
|                                                   |   
|8. COMPENSATION FOR IMBALANCES                     | 19
|                                                   |   
|9. PRESSURE AT THE ENTRY AND EXIT POINTS           | 19



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|10. NON-COMPLIANCE DUE TO LOW PRESSURE OR POOR GAS QUALITY AT THE EXIT POINT | 19
|---------------------------------------------------------------------------- | --
|                                                                             |   
|11. SUSPENSION                                                               | 20
|                                                                             |   
|CHAPTER IV                                                                   | 21
|                                                                             |   
|FINANCIAL CONDITIONS                                                         | 21
|                                                                             |   
|1. APPLICABILITY OF THE SERVICE                                              | 21
|                                                                             |   
|2. CHARGES                                                                   | 21
|                                                                             |   
|3. INVOICING                                                                 | 22
|                                                                             |   
|4. PAYMENTS                                                                  | 23
|                                                                             |   
|5. DEFAULT                                                                   | 24
|                                                                             |   
|6. ESTIMATED VALUE OF THE CONTRACT                                           | 24
|                                                                             |   
|7. DISCOUNTS ON THE FIXED CHARGE                                             | 24
|                                                                             |   
|8. SIGNATURES                                                                | 25
|                                                                             |   
|EXHIBIT I                                                                    | 26
|                                                                             |   
|SPECIFICATIONS REGARDING NATURAL GAS                                         | 26
|                                                                             |   
|EXHIBIT II                                                                   | 27
|                                                                             |   
|MEASUREMENT                                                                  | 27
|                                                                             |   
|EXHIBIT III                                                                  | 32
|                                                                             |   
|GUARANTEE AMOUNT                                                             | 32



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