EXHIBIT 10.6.8 AMENDMENT NO. 4 TO SECURITY AGREEMENT AND CHATTEL MORTGAGE (AIRCRAFT NO. N5O5MC)(1) THIS FOURTH AMENDMENT TO THE SECURITY AGREEMENT AND CHATTEL MORTGAGE is dated as of May 31, 2005, (this "AMENDMENT"), and entered into by and between Atlas Freighter Leasing III, Inc., a Delaware corporation ("BORROWER"), and Deutsche Bank Trust Company Americas, as agent for and representative of ("ADMINISTRATIVE AGENT") the financial institutions ("LENDERS") party to the Amended and Restated Credit Agreement referred to below. W I T N E S S E T H; WHEREAS, Borrower is party to that certain Credit Agreement, dated as of April 25, 2000, among Borrower, the Lenders from time to time party thereto and the Administrative Agent (as amended, modified and/or supplemented to, but not including, the date hereof, the "CREDIT AGREEMENT"). WHEREAS, pursuant to that certain Amended and Restated Credit Agreement, dated as of July 27, 2004, among Borrower, the Lenders from time to time party thereto and the Administrative Agent (as amended, modified and/or supplemented from time to time, the "AMENDED AND RESTATED CREDIT AGREEMENT"), Borrower has agreed to further amend and restate the Credit Agreement. WHEREAS, Borrower and the Administrative Agent are parties to that certain Security Agreement and Chattel Mortgage with respect to one Boeing 747-2D3B, U.S. Registration No. N5O5MC, Manufacturer's Serial Number 21251, dated as of April 25, 2000, between the Borrower and the Agent, recorded by the Federal Aviation Administration on May 24, 2000, as Conveyance No. DD018943, supplemented by Supplemental Chattel Mortgage No. 1 dated as of November 13, 2000, recorded on December 20, 2000, as Conveyance No. SS016138, amended by Amendment No. 1 to Security Agreement and Chattel Mortgage dated as of October 30r20(0)l, recorded January 9, 2002, as Conveyance No. SS018002, amended by Amendment No. 2 to Aircraft Chattel Mortgage dated as of June 14, 2002, recorded August 21, 2002, as Conveyance No. YY034496, amended by Amendment No. 3 to Security Agreement and Chattel Mortgage dated as of July 27, 2004, recorded August 24, 2004 as Conveyance No. NN027686 (the "AIRCRAFT CHATTEL MORTGAGE"). - ---------- (1) This Amendment to the Security Agreement and Chattel Mortgage has been executed in several counterparts. To the extent, if any, that this Amendment to the Security Agreement and Chattel Mortgage constitutes chattel paper (as such term is defined in the Uniform Commercial Code as in effect in any applicable jurisdiction), no security interest in this Amendment to the Security Agreement and Chattel Mortgage may be created through the transfer or possession of any counterpart other than the original. The counterpart to be deemed the original shall be the counterpart that contains the receipt therefor executed by Deutsche Bank Trust Company Americas, as Administrative Agent, on the signature page thereof and no security interest in this Amendment to the Security Agreement and Chattel Mortgage may be created through the transfer of any counterpart other than said original counterpart. WHEREAS, subject to the terms and conditions set forth below, the parties hereto wish to amend certain provisions of the Aircraft Chattel Mortgage as provided herein. NOW THEREFORE, it is agreed: A. AMENDMENT TO AIRCRAFT CHATTEL MORTGAGE 1. The proviso to Section 4(g)(ii) of the Aircraft Chattel Mortgage is hereby amended by (x) deleting the text "$50,000,000" appearing therein, and (y) inserting the text "$15,000,000" in lieu thereof. B. MISCELLANEOUS PROVISIONS 1. This Amendment may be executed in any number of counterparts and by the different parties hereto on separate counterparts, each of which counterparts when executed and delivered (including by way of facsimile or electronic transmission) shall be an original, but all of which shall together constitute one and the same instrument. A complete set of counterparts shall be lodged with Borrower and the Administrative Agent. 2. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAW OF THE STATE OF NEW YORK. 3. This Amendment is limited as specified and shall not constitute a modification, acceptance or waiver of any other provision of the Aircraft Chattel Mortgage. 4. From and after the date hereof, all references in the Aircraft Chattel Mortgage to the Aircraft Chattel Mortgage shall be deemed to be references to the Aircraft Chattel Mortgage as modified hereby. * * * -2- IN WITNESS WHEREOF, the undersigned have caused this Amendment to be duly executed and delivered as of the date first above written. ATLAS FREIGHTER LEASING III, INC. By: /s/ William C. Bradley ------------------------------ Name: William C. Bradley Title: Treasurer & Secretary Mortgage Amendment (N505MC) DEUTSCHE BANK TRUST COMPANY AMERICAS, as Agent By: /s/ Mark B. Cohen ------------------------------ Name: Mark B. Cohen Title: Managing Director By: /s/ Steven A. Cohen ------------------------------ Name: Steven A. Cohen Title: Director Mortgage Amendment (N505MC) Schedule to Exhibit 10.6.8 The agreements listed below are substantially identical to this exhibit and are not being filed separately as exhibits pursuant to instruction 2 to Regulation S-K, Item 601. - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- REGISTRATION MANUFACTURER'S SERIAL AGENT BORROWER AGREEMENT NUMBER NUMBER(S) - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N509MC 21221 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N509MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N512MC 21220 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N512MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N517MC 23300 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N517MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N522MC 21783 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N522MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N523MC 21782 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N523MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N524MC 21784 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N524MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N526MC 22337 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N526MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N527MC 22471 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N527MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N528MC 22472 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N528MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N534MC 21832 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N534MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N808MC 21048 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N808MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- N809MC 20887 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Trust Company III Agreement (N809MC) dated as Americas of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- CF6-50E2 Spare 530168; 517530; Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Engines 517790; 517602; Trust Company III Agreement (CF6-50E2 Spare 517547; 517,538; Americas Engines) dated as of May 517,539; 455167; 530255 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- ----------------------------- CF6-80C2 BSF Spare 704,699; 704860; 704918 Deutsche Bank Atlas Freighter Leasing Amendment No. 4 to Security Engines Trust Company III Agreement (CF6-50E2 Spare Americas Engines) dated as of May 31, 2005 - -------------------- ------------------------ ---------------- ------------------------- -----------------------------