Exhibit 10.44 ------------- 6-1162-MDH-638 United Air Lines, Inc. P.O. Box 66100 Chicago, Illinois 60666 Subject: Letter Agreement No. 6-1162-MDH-638 to Purchase Agreement No. 1485 - [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] Reference is made to Purchase Agreement No. 1485 dated October 25, 1988, between The Boeing Company {Boeing} and United Air Lines, Inc. {Buyer} {the Purchase Agreement} relating to the sale by Boeing and the purchase by Buyer of Model 757-222 aircraft {the Aircraft}. All terms used herein and in the Purchase Agreement, and not defined herein, shall have the same meaning as in the Purchase Agreement. [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] United Air Lines, Inc. 6-1162-MDH-638 Page 2 Boeing and Buyer will maintain a [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] is set forth in Attachment A to this Letter Agreement. b. Credit Memorandum. ----------------- Within ten {10} days of the date of signing of this Letter Agreement Boeing shall issue to Buyer a credit memorandum for the Aircraft scheduled for delivery to Buyer [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]. Boeing shall transfer the amount of such Credit Memorandum to a bank designated in writing by Buyer. At the time of delivery of the Aircraft scheduled for delivery [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]. On or before March 31, 1999, [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]. United Air Lines, Inc. 6-1162-MDH-638 Page 3 [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]. United Air Lines, Inc. 6-1162-MDH-638 Page 4 [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT]. Very truly yours, THE BOEING COMPANY By /s/ M.D. Hurt ------------- Its Attorney-in-Fact ---------------- ACCEPTED AND AGREED TO this Date: January 5, 1998 --------------- UNITED AIR LINES, INC. By /s/ Douglas A. Hacker --------------------- Douglas A. Hacker Its Senior Vice President and ------------------------- Chief Financial Officer Attachment A to 6-1162-MDH-638 Page 1 [*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT] United Air Lines, Inc. 6-1162-MDH-638 Page 2 United Air Lines, Inc. 6-1162-MDH-638 Page 3