Exhibit
      10.5

    


    LETTER
      AGREEMENT

    


    By
      this
      Letter Agreement entered into as of June 20, 2007, for good and valuable
      consideration the adequacy of which is hereby acknowledged, and intending to
      be
      legally bound, the Shareholders and IMTT Holdings Inc. (collectively with its
      subsidiaries, the “Company”) agree to the following: 

    


    i)
      In the
      event of the issuance of tax exempt Gulf Opportunity Zone Bonds (“GO Zone
      Bonds”) by the Company, the Shareholders shall cause the Members of the Board
      appointed by them to, and the Company shall, declare and pay a dividend with
      respect to each Fiscal Quarter in accordance with the requirements and
      conditions set forth in Section 4 of the Shareholders’ Agreement with
      adjustments as set out in Schedule 1. In the event that it becomes definitively
      known that less than $215 million face value of GO Zone Bonds will be issued
      by
      the Company, the parties agree that the adjustments as set forth in Schedule
      1
      shall be prorated based upon the cumulative GO Zone Bonds actually issued as
      against $215 million of anticipated Go Zone Bonds; and

    


    ii)
      The
      parties agree that for the purposes only of Section 5 of the Shareholders’
Agreement (and specifically not Sections 4(d) and 4(e) of the Shareholders’
Agreement), Net Debt shall be reduced by an amount equal to the cumulative
      net
      adjustments made to dividends declared and paid by the Company pursuant to
      clause (i) of this Agreement (including such adjustments made with respect
      to
      the most recent Fiscal Quarter); and

    


    iii)
      For
      the avoidance of doubt, no provision of this Letter Agreement is intended to
      amend the requirement in Section 4 of the Shareholders’ Agreement that the
      declaration and payment of dividends by the Company be subject to the
      following:

    


    
      	 	
              a)

            	
              such
                dividend is permitted by the terms of the financing agreements of
                the
                Company and by applicable law;

            


    

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    
      	 	
              b)

            	
              the
                payment of the dividend would not result in the Company retaining
                insufficient reserves of cash, cash equivalents and/or committed
                and
                unutilized credit facilities to enable the Company to meet the normal
                requirements of its business and to fund Capital Expenditure previously
                approved by the Board;

            


    

    


    
      	 	
              c)

            	
              Section
                4(d) and 4(e) of the Shareholders’
Agreement.

            


    

    


    The
      Shareholders and the Company further agree that this Letter Agreement
      constitutes an amendment to the Shareholders Agreement dated April 14, 2006
      (as
      amended) between the Shareholders and the Company (the “Shareholders’
Agreement”) and that, except as set forth herein, that Shareholders’ Agreement
      shall remain in full force and effect. Capitalized terms in this Letter
      Agreement shall be as defined in the Shareholders’ Agreement unless otherwise
      defined herein. This Amendment may be executed and delivered (including by
      facsimile transmission) in one or more counterparts, each of which when executed
      shall be deemed to be an original, but all of which taken together shall
      constitute one and the same agreement. This Letter Agreement shall be governed
      by, and construed in accordance with, the laws of the State of Delaware.


     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    
      	 	 	 
	 	IMTT
              HOLDINGS INC.
	 
 	 
 	 
 
	
            	By:  	/s/ Thomas
              B. Coleman
	 	
              
Name:
              THOMAS B. COLEMAN
	 	Title:
              CHIEF EXECUTIVE OFFICER


    

    
      
        	 	 	 
	 	SHAREHOLDERS: 
	 	 
	 	MACQUARIE
                TERMINAL HOLDINGS LLC
	 
 	 
By: 	
                 
Macquarie
                  Infrastructure Company Inc. (d/b/a 

                Macquarie
                  Infrastructure Company (US)) 

              
	 	 	 
	
              	By:  	/s/ Peter
                Stokes
	 	
                
Name:
                PETER STOKES
	 	Title:
                CHIEF EXECUTIVE OFFICER


      

      
        
          	 	 	 
	 	
                  CURRENT
                    BENEFICIAL SHAREHOLDERS ARE 

                  HEREIN
                    REPRESENTED BY:

                
	 	 
	 	
                  JAMES J. COLEMAN JR., THOMAS B. COLEMAN 

                  AND JAMES OWEN COLEMAN, TRUSTEES OF 

                  VOTING TRUST AGREEMENT DATED MAY 2, 2006


                  AS AMENDED ON JANUARY 11, 2007. 

                
	 
 	 
 	 
 
	
                	By:  	/s/ Thomas
                  B. Coleman
	 	
                  
THOMAS
                  B. COLEMAN, TRUSTEE


        

        
          
            	 


            	 	 	 
	
                  	By:  	/s/
                    James J. Coleman 
	 	
                    
JAMES
                    J. COLEMAN JR., TRUSTEE


            	 


            	 	 	 
	
                  	By:  	/s/
                    James O. Coleman 
	 	
                    
JAMES
                    O. COLEMAN,
                    TRUSTEE




          
            
               

            

            
               

              
                

              

            

            
               

            

          

        

      

    

    Schedule
      1

    


    


    THIS
      SCHEDULE IS BASED UPON THE ISSUANCE OF

    $215
      MILLION OF GO ZONE BONDS

    


    For
      each
      Fiscal Quarter beginning with the Fiscal Quarter ended March 31, 2009 through
      the Fiscal Quarter ended December 31, 2010 the dividend declared and paid by
      the
      Company to the Shareholders will be increased
      by the
      following amounts:

    


    
      	
            	·	
              All
                Fiscal Quarters in 2009: $3,400,000 increase per Fiscal
                Quarter 

            


    

    
      	
            	·	
              All
                Fiscal Quarters in 2010: $1,300,000 increase per Fiscal
                Quarter 

            


    

    


    For
      each
      Fiscal Quarter beginning with the Fiscal Quarter ended March 31, 2011 through
      the Fiscal Quarter ended September 30, 2015 the dividend declared and paid by
      the Company to the Shareholders will be decreased
      by the
      following amounts:

    


    
      	
            	·	
              All
                Fiscal Quarters in 2011: $300,000 decrease per Fiscal Quarter  

            


    

    
      	
            	·	
              All
                Fiscal Quarters in 2012: $600,000 decrease per Fiscal Quarter  

            


    

    
      	
            	·	
              All
                Fiscal Quarters in 2013: $1,100,000 decrease per Fiscal
                Quarter 

            


    

    
      	
            	·	
              All
                Fiscal Quarters in 2014: $1,600,000 decrease per Fiscal
                Quarter 

            


    

    
      	
            	·	
              First
                two Fiscal Quarters in 2015: $1,600,000 decrease per Fiscal
                Quarter 

            


    

    
      	 	
              ·

            	
              Fiscal
                Quarter ended September 30, 2015: $1,200,000
                decrease.