Exhibit 10.5 Supplemental Agreement No. 4 to Purchase Agreement No. 2061 between The Boeing Company and Continental Airlines, Inc. Relating to Boeing Model 777 Aircraft THIS SUPPLEMENTAL AGREEMENT, entered into as of February 3, 1999, by and between THE BOEING COMPANY, a Delaware corporation with its principal office in Seattle, Washington, (Boeing) and CONTINENTAL AIRLINES, INC., a Delaware corporation with its principal office in Houston, Texas (Customer); WHEREAS, the parties hereto entered into Purchase Agreement No. 2061 dated October 10, 1997, (the Purchase Agreement) relating to Boeing Model 777-200IGW aircraft, (Aircraft); and WHEREAS, Boeing and Customer have mutually agreed to revise the delivery of Option Aircraft in Letter Agreement 2061-1R1 by deleting Option Aircraft delivering in [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] and adding Option Aircraft in [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]; and WHEREAS, Boeing and Customer have mutually agreed to amend the Purchase Agreement to incorporate the effect of these and certain other changes; NOW THEREFORE, in consideration of the mutual covenants herein contained, the parties agree to amend the Purchase Agreement as follows: 1. Table of Contents: Remove and replace, in its entirety, the "Table of Contents", with the Table of Contents attached hereto, to reflect the changes made by this Supplemental Agreement No. 4. 2. Letter Agreements: Remove and replace, in its entirety, Letter Agreement 2061-1R1 "Option Aircraft" with the revised Letter Agreement 2061- 1R2, attached hereto, to reflect the revised delivery of Option Aircraft. The Purchase Agreement will be deemed to be supplemented to the extent herein provided as of the date hereof and as so supplemented will continue in full force and effect. EXECUTED IN DUPLICATE as of the day and year first written above. THE BOEING COMPANY CONTINENTAL AIRLINES, INC. By: /s/ D. M. Hurt By: /s/ Brian Davis Its: Attorney-In-Fact Its: Vice President TABLE OF CONTENTS ARTICLES Revised By: 1. Quantity, Model and Description 2. Delivery Schedule 3. Price 4. Payment 5. Miscellaneous TABLE 1. Aircraft Information Table SA No. 2 EXHIBIT A. Aircraft Configuration B. Aircraft Delivery Requirements and Responsibilities SUPPLEMENTAL EXHIBITS BFE1. BFE Variables CS1. Customer Support Variables EE1. Engine Escalation/Engine Warranty and Patent Indemnity SLP1. Service Life Policy Components TABLE OF CONTENTS LETTER AGREEMENTS Revised By: 2061-1R2 Option Aircraft SA No. 4 2061-2 Demonstration Flights 2061-3 Installation of Cabin Systems Equipment 2061-4 Spares Initial Provisioning 2061-5 Flight Crew Training Spares [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUST FOR CONFIDENTIAL TREATMENT] TABLE OF CONTENTS CONFIDENTIAL LETTER AGREEMENTS Revised By: 6-1161-GOC-087 Aircraft Performance Guarantees 6-1162-GOC-088 Promotion Support 6-1162-GOC-089R1 Special Matters SA No. 3 6-1162-GOC-172 Additional Matters SA No. 1 SUPPLEMENTAL AGREEMENTS Dated as of: Supplemental Agreement No. 1 December 18, 1997 Supplemental Agreement No. 2 July 30, 1998 Supplemental Agreement No. 3 September 25, 1998 Supplemental Agreement No. 4 February 3, 1999 February 1999 2061-1R2 Continental Airlines, Inc. 1600 Smith Street Houston, TX 77002 Subject: Option Aircraft Reference: Purchase Agreement No. 2061 (the Purchase Agreement) between The Boeing Company (Boeing) and Continental Airlines, Inc. (Customer) relating to Model 777- 200IGW aircraft (the Aircraft) Ladies and Gentlemen: This Letter Agreement amends and supplements the Purchase Agreement. All terms used but not defined in this Letter Agreement have the same meaning as in the Purchase Agreement. This Letter Agreement supersedes and replaces in its entirely Letter Agreement 2061-1 dated October 10, 1997. Boeing agrees to manufacture and sell to Customer additional Model 777-200IGW aircraft as Option Aircraft. The delivery months, number of aircraft, Advance Payment Base Price per aircraft and advance payment schedule are listed in the Attachment to this Letter Agreement (the Attachment). 1. Aircraft Description and Changes 1.1 Aircraft Description: The Option Aircraft are described by the Detail Specification listed in the Attachment. 1.2 Changes: The Detail Specification will be revised to include: (i) Changes applicable to the basic Model 777 aircraft which are developed by Boeing between the date of the Detail Specification and the signing of the definitive agreement to purchase the Option Aircraft; (ii) Changes required to obtain required regulatory certificates; and (iii) Changes mutually agreed upon. 2. Price 2.1 The pricing elements of the Option Aircraft are listed in the Attachment. 2.2 Price Adjustments. 2.2.1 Optional Features. The Optional Features Prices for the Option Aircraft will be adjusted to Boeing's current prices as of the date of execution of the definitive agreement for the Option Aircraft. 2.2.2 Escalation Adjustments. The Airframe Price and the Optional Features Prices for Option Aircraft delivering before January 2003, will be escalated on the same basis as the Aircraft. The engine manufacturer's current escalation provisions, listed in Exhibit Supplement EE1 to the Purchase Agreement, have been estimated to the months of scheduled delivery using commercial forecasts to calculate the Advance Payment Base Price listed in the Attachment to this Letter Agreement. The engine escalation provisions will be revised if they are changed by the engine manufacturer prior to the signing of a definitive agreement for the Option Aircraft. 2.2.3 Base Price Adjustments. The Airframe Price and the Engine Price of the Option Aircraft delivering before January, 2003, will be adjusted to Boeing's and the engine manufacturer's then current prices as of the date of execution of the definitive agreement for the Option Aircraft. 2.2.4 Prices for Long Lead Time Aircraft. Boeing and the engine manufacturer have not established prices and escalation provisions for Model 777-200IGWaircraft and engines for delivery in the year 2003 and after. When prices and the pricing bases are established for the Model 777-200IGW aircraft delivering in the year 2003 and after, the information listed in the Attachment will be appropriately amended. 3. Payment. 3.1 Customer will pay a deposit to Boeing in the amount shown in the Attachment for each Option Aircraft (Deposit), on the date of this Letter Agreement. If Customer exercises an option, the Deposit will be credited against the first advance payment due. If Customer does not exercise an option, Boeing will retain the Deposit for that Option Aircraft. 3.2 Following option exercise, advance payments in the amounts and at the times listed in the Attachment will be payable for the Option Aircraft. The remainder of the Aircraft Price for the Option Aircraft will be paid at the time of delivery. 4. Option Exercise. Customer may exercise an option by giving written notice to Boeing on or before the date [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATEMENT] months prior to the first business day of the applicable delivery month listed in the Attachment (Option Exercise Date). 5. Contract Terms. Boeing and Customer will use their best efforts to reach a definitive agreement for the purchase of an Option Aircraft, including the terms and conditions contained in this Letter Agreement, in the Purchase Agreement, and other terms and conditions as may be agreed upon to add the Option Aircraft to the Purchase Agreement as an Aircraft. In the event the parties have not entered into a definitive agreement within 30 days following option exercise, either party may terminate the purchase of such Option Aircraft by giving written notice to the other within 5 days. [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATEMENT] Very truly yours, THE BOEING COMPANY By: /s/ D. M. Hurt Its Attorney-In-Fact ACCEPTED AND AGREED TO this Date: February 3, 1999 CONTINENTAL AIRLINES, INC. By /s/ Brian Davis Its Vice President Attachment Attachment to Letter Agreement 2061-1R2 Option Aircraft Delivery, Description, Price and Advance Payments [CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATEMENT]